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    • 专利摘要:
    rotary valve actuator, and, damping apparatus rotary valve actuators having a partial stroke damping apparatus are described herein. an example of the rotary valve actuator described herein includes a housing containing a first piston and a second piston opposite the first piston, in which the pistons move in opposite directions to rotate an axis of the rotary valve actuator. a shock absorber is operatively coupled to at least one of the first piston or the second piston to slow the movement of the piston to only part of a stroke of the rotary valve actuator.
    公开号:BR112012002900B1
    申请号:R112012002900-2
    申请日:2010-08-30
    公开日:2020-08-11
    发明作者:Gerard ter Horst；Erwin van Dorp
    申请人:Emerson Process Management Valve Automation, Inc；
    IPC主号:
    专利说明:

    FIELD OF DISSEMINATION
    [0001] This patent refers generally to actuators and, more particularly, to rotary valve actuators with partial stroke damping apparatus. FUNDAMENTALS
    [0002] Plants or process control systems often employ rotary valves, such as butterfly valves, to control the flow of process fluids. In general, rotary valves typically include a fluid flow control element arranged in a fluid flow path between an inlet and an outlet of the rotary valve. The fluid flow control element is rotatably coupled to the rotary valve body via an axis. Normally, a portion of the shaft extending from the rotary valve is operationally coupled to an actuator (for example, a pneumatic actuator, a hydraulic actuator, etc.) that rotates the valve shaft in the first direction and in the second direction opposite the first direction .
    [0003] In operation, a control unit (for example, a positioner) can supply a control fluid (for example, air) to the actuator to position the fluid flow control element in a desired position to regulate or suppress the fluid flow through the rotary valve. The actuator can move the fluid flow control element through a full stroke between a fully open position to allow fluid to flow through the valve and a fully closed position to prevent fluid from flowing through the valve.
    [0004] Rotary valve actuators, such as rack and pinion actuators, are widely used to implement, for example, quarter-turn rotary valves. A rack and pinion actuator converts the straight movement of two opposed pistons into rotational movement of the valve shaft. Rack and pinion actuators generally provide relatively high output torque and a compact physical footprint or envelope. However, rack and pinion actuators may require a damping mechanism to provide a cushioning and / or deceleration effect to prevent noise, impact and / or damage to the actuator components.
    [0005] However, some known damping mechanisms used with rotary actuators dampen the movement of the actuator over an entire stroke of the actuator. For example, these known damping mechanisms can dampen or slow the pistons over an entire closing stroke. This configuration significantly reduces the efficiency of the actuator and significantly reduces or limits the overall closing speed and output torque provided by the actuator. SUMMARY
    [0006] An exemplary rotary valve actuator described here includes a housing that contains a first piston and a second piston opposite the first piston, where the pistons move in opposite directions to rotate a rotary valve actuator shaft. A damper is operationally coupled to at least one of the first piston or the second piston to show the movement of the piston for only a portion of a rotary valve actuator stroke.
    [0007] In another example, a damping apparatus for use with a rotary valve actuator includes a valve shaft operatively coupled to a rotary valve actuator where the rotary valve actuator rotates the valve shaft in the first and second directions direction opposite the first direction. A cam is attached to one end of the valve shaft. A viscosity damper is coupled to a rotary valve actuator housing. The viscosity damper includes a moving element that must be engaged by the cam only over a portion of a rotary valve actuator stroke. BRIEF DESCRIPTION OF THE DRAWINGS
    [0008] FIGS. 1A-1B illustrate a known double-acting rotary valve actuator.
    [0009] FIG. 2 illustrates a known damping apparatus operationally coupled to the rotary valve actuator of FIGS. 1A-1B.
    [0010] FIG. 3 illustrates exemplary actuator with an exemplary damping apparatus described here.
    [0011] FIGS. 4A-4D illustrate another exemplary damping apparatus described here that can be used to implement the exemplary actuator of FIGS. 3A-3B.
    [0012] FIGS. 5A-5E illustrate another exemplary damping apparatus described here that can be used to implement the exemplary actuator of FIGS. 3A-3B.
    [0013] FIGS. 6A-6B illustrate yet another exemplary damping apparatus described here that can be used to implement the exemplary actuator of FIGS. 3A-3B.
    [0014] FIGS. 7A-7C illustrate yet another exemplary actuator with a damping apparatus described here.
    [0015] FIG. 8 illustrates another exemplary damping apparatus described here that can be used to implement the exemplary actuator of FIGs. 7A-7C.
    [0016] FIGS. 9-17 illustrate an exemplary alternative damping apparatus described here that can be used to provide an actuator of FIGs. 1A-1B with partial stroke damping. DETAILED DESCRIPTION
    [0017] The exemplary actuator device described here can be used with, for example, rotary valves (for example, quarter-turn valves). The exemplary actuator devices described here are implemented with a damper to decrease the actuator speed for only a portion of the complete stroke of the actuator. More specifically, the exemplary actuator apparatus described here provides partial stroke damping at, for example, an end of a closing stroke, as the actuator moves a flow control member of a rotary valve between an open position and a closed position. The exemplary actuator may be a double-acting actuator, a single-acting actuator, a Scottish yoke actuator, a vane type actuator, or any other suitable rotary actuator.
    [0018] In general, the exemplary damping devices described here are operationally coupled to an actuator to provide damping for only a portion of the complete stroke of the actuator. In one example, the damping apparatus includes a damper operationally coupled to at least one of a first piston or a second piston of the actuator to decrease the movement of the pistons to only a portion of an actuator stroke. Examples of such devices are described in more detail below in connection with FIGs. 5A-5B, 6A-6C, 9-17.
    [0019] Additionally, in some examples, the damping apparatus also includes a first circuit and fluid path and a second circuit or fluid path in fluid communication with the inner chamber of the actuator. Examples of these devices are described in more detail below in connection with FIGs. 4A-4E, 7 and 8.
    [0020] In comparison to the exemplary damping apparatus described here, some known actuating apparatus implement a flow restrictor in an escape path from the actuator to provide stroke damping. However, this stroke damping apparatus is known to slow the pistons over an entire stroke (e.g., a complete closing stroke) of the actuator, thereby affecting the efficiency and performance of the actuator. In addition, this known damping device is often mounted externally in relation to an actuator housing, which generally increases the limit or physical or dimensional area of the actuator.
    [0021] Before discussing the exemplary actuators with partial stroke damping apparatus in detail, a brief description of a known rotary control valve assembly 100 is provided in FIGs. 1A and 1B. Referring to FIGs. 1A and 1B, the rotary valve actuator 102 (for example, the rack and pinion type actuator) is coupled to a valve body 104 of the rotary valve 106 via a castle 108. The valve body 104 defines a flow path of fluid between an inlet 110 and an outlet 112. A fluid flow control element 114 is disposed within the fluid flow path to regulate the fluid flow between inlet 110 and outlet 112. The flow control member 114 it is rotatably coupled with respect to a valve seat (not shown) disposed within the valve body 104 via a valve shaft 116. As shown, one end17 of the valve shaft 116 is operationally coupled to actuator 102 via a drive shaft 118 of actuator 102.
    [0022] Actuator 102 includes a first piston 120 and a second piston 122 arranged within a housing 124 to define an internal control chamber 126 and respective external control chambers 128 and 130. The pistons 120 and 122 include respective body portions 132 and 134 having racks or gears 136 and 138 to fit a pinion 140 of the drive shaft 118. The housing 124 includes a first port 142 in fluid communication with the external control chambers 128 and 130 via a passage 144 defined by the housing 124 compartment 124 also includes a second port 146 in fluid communication with the internal control chamber 126 to provide and / or remove pressurized fluid from the internal control chamber 126.
    [0023] FIG. 2 schematically illustrates a known damping apparatus 200 operatively coupled to the set of known control rotary valves 100 of FIGs. 1 A and 1B. Referring to FIG. 2, the damping apparatus 200 includes a solenoid valve 202 mounted externally in relation to the actuator 102. The solenoid valve 202 moves between a first position 204 to fluidly couple the second port 146, and an internal control chamber 126 for a source of fluid supply 206 and a second position 208 for fluidly coupling the second port 146 and an internal control chamber 126 for a fluid flow restrictor 210. In this example, in comparison to the exemplary damping apparatus described here, the damping apparatus known 200 dampens or slows down the stroke of pistons 120 and 122 to a full or full stroke (e.g., a full closing stroke) of actuator 102 when pistons 120 and 122 move toward the axis of valve 116.
    [0024] In operation, referring to FIGs. 1A, 1B, and 2, the inner chamber 126 and the outer control chambers 128 and 130 receive pressurized fluid to move the pistons 120 and 122 in a straight line moving away and towards the valve axis 116. The straight movement of the pistons 120 and 122 is converted into rotation movement of valve shaft 116 via racks 136 and 138 and both pinion 140 and pistons 120 and 122 move in opposite directions within housing 124. The rotation of valve shaft 116 makes the member flow control 114 rotate to the desired angular position to vary or control the flow of fluid through valve 106. For example, rotation of valve shaft 116 in the first direction (for example, counterclockwise) moves a limb flow control 114 of valve 106 to an open position to allow or increase fluid flow through valve 106 and rotation of valve shaft 116 in the second direction (e.g., clockwise) moves the control member and flow from valve 106 to a closed position to decrease or prevent fluid flow through valve 106.
    [0025] To rotate the valve shaft 116 in the first direction (for example, counterclockwise) indicated by arrow 148 of FIG. 1B, the solenoid valve 202 is moved to the first position 204 to fluidly couple the fluid supply source 206 to the internal control chamber 126 of the actuator 102. The internal control chamber 126 receives the pressurized fluid (for example, compressed air) from a fluid supply source 206 via a first fluid path 212 and a second port 146. A control fluid (e.g., air) supplied in the internal control chamber 126 via the second port 146 having a pressure greater than a pressure of a fluid (for example, air) in the external control chambers 128 and 130 moves the pistons 120 and 122 in the direction indicated by arrows 150 and 152 and makes the valve shaft 116 rotate in the first direction 148. Any fluid in the control chambers external 128 and 130 is ventilated via passage 144 of compartment 124 and the first port 142.
    [0026] To rotate the valve shaft 116 in the second direction opposite the first direction 148, the damping apparatus 200 is moved to the second position 208 to fluidly couple the internal control chamber 126 to the fluid flow restrictor 210 via the second fluid path 214. The pressurized fluid from the internal control chamber 126 is vented via the second port 146 and pressurized fluid is supplied in the external control chambers 128 and 130 via the first port 142 and the passage 144. The pressurized fluid in the chambers external control valves 128 and 130 cause pistons 120 and 122 to move towards valve shaft 116 (for example, a closing stroke) to cause valve shaft 116 to rotate in the second direction (for example, clockwise). As pistons 120 and 122 move towards the axis of valve 116, fluid flow restrictor 210 restricts fluid flow through second fluid path 214. As a result, the movement or speed of pistons 120 and 122 is reduced or damped for a full stroke of the actuator 102 in which the pistons 120 and 122 are moved towards the valve shaft 116 (for example, a complete closing stroke).
    [0027] In comparison with the exemplary damping apparatus described here, the known damping apparatus 200 includes fluid flow restrictor 210 in a configuration that is disadvantageous due to damping apparatus 200 damping or slowing pistons 120 and 122 over substantially an entire or full stroke for which pistons 120 and 122 move towards the valve shaft 116. Therefore, the damping device 200 restricts the travel speed over the entire stroke, thereby significantly affecting performance and the efficiency of actuator 102. In addition, the damping apparatus 200 is mounted externally in relation to compartment 124 of actuator 102, thus generally increasing the dimensional limit of the set of rotary control valves 100.
    [0028] FIG. 3 illustrates an exemplary rotary valve actuator 300 having a damping apparatus 302 described here. The exemplary damping device 302 described here can be used with double acting actuators, single acting actuators, rack and pinion actuators, Scottish yoke actuators, vane actuators or any other suitable actuator.
    [0029] In this example, the exemplary actuator 300 is a rack and pinion type actuator, with simple action. The actuator 300 includes a housing 304 having a first piston 306 and a second piston 308 arranged therein to define an inner chamber 310, a first outer chamber 312 and a second outer chamber 314. The first and second piston 306 and 308 include respective portions of body or rack 316 and 318 that mate with a drive shaft or pinion 320 of a valve shaft 322. The valve shaft 322 is operationally coupled to a fluid flow control element (for example, the flow control element fluid 114 of FIG. 1A) from a valve (e.g., rotary valve 106). Induction elements or springs 324 and 326 are arranged within the respective outer chamber 312 and 314 of housing 304 to induce pistons 306 and 308 towards valve shaft 322. In this example, housing 304 includes a first port 328 and a second port 330 in fluid communication with inner chamber 310. Housing 304 also includes a third port 332 in fluid communication with outer chambers 312 and 314 via a passage 334.
    [0030] In general, the damping apparatus 302 decreases the movement of pistons 306 and / or 308 over only a portion of a stroke of the actuator 300. In this example, the damping apparatus 302 includes a damper or locking element 336 operably coupled to the first piston 306. The first piston 306 moves the buffer 336 between a first position to allow fluid flow between the inner chamber 310 and the first port 328 and a second position to substantially restrict fluid flow between the inner chamber 310 and the first port 328 along a portion of the stroke of the actuator 300. For example, damper 336 can be configured to block or restrict the flow of fluid through the first port 328 over only a portion of the stroke of the actuator during which the fluid in the inner chamber 310 is removed or exhausted by ventilation 352.
    [0031] Additionally, in this example, the damping apparatus 302 also includes a first fluid circuit 338 and a second fluid circuit 340. In this example, the first fluid circuit 338 includes a first fluid path 342 fluidly coupled to the inner chamber 310 of compartment 304 via the first port 328. The second fluid circuit 340 includes the second fluid path 344 fluidly coupled to the inner chamber 310 via the second port 330. The second fluid circuit 340 also includes a restrictor 346 such as, for example, example, a fluid restrictor (for example, a drain valve) to restrict the flow of fluid through the second fluid path 344. In other words, the restrictor 346 restricts the flow of fluid through the second fluid path 344 so that fluid flows through the second fluid path 344, when the first piston 306 is in the second position (for example, damper 336 is restricting the flow of fluid through the first port 328), is less than the fluid flow between the inner chamber 310 and the first port 328 when the buffer 336 is positioned away from the first port 328. The restrictor 346 can be adjustable to increase or decrease the constraint (for example, the fluid flow rate) through the second fluid path 344.
    [0032] Additionally, in this example, the damping apparatus 302 includes the third fluid path 348 having a one-way valve 350 (e.g., a check valve) that allows fluid to flow in the first direction and that substantially restricts or prevents flow of fluid in a second direction opposite the first direction. In this example, the third fluid path 348 is fluidly coupled to an inner chamber 310 via the second port 330. However, in other examples, the third fluid path 348 can be fluidly coupled to the inner chamber via the first port 328. In yet other examples, the one-way valve 350 can be integrally formed with the buffer 336.
    [0033] Although the first and second fluid circuit 338 and 340 are schematically illustrated, the first and second fluid circuit 338 and 340 can be integrally formed with, arranged within, or coupled to compartment 304, ports 328 and / or 330, and / or pistons 306 and 308. For example, restrictor 346 and / or one-way valve 350 can be arranged within second port 330, within compartment 304, and / or coupled to piston 306 (for example, disposed within the body portion 316). For example, restrictor 346 and one-way valve 350 can be integrally formed with damper 336. An example of this is illustrated in FIGs. 5A-5E and 6A-6B. In another example, the one-way valve 350 can be integrally formed with the buffer 336 and the restrictor 346 can be disposed within the second port 330. An example of this is illustrated in FIGS. 7A-7C and FIG. 8. In yet another example, the one-way valve 350 and the restrictor 346 can be disposed within the body portion 316 of piston 306. An example of this is illustrated in FIG. 15.
    [0034] As shown, the first fluid path 342 fluidly couples the inner chamber 310 of the actuator 300 for, for example, ventilation 352. The third fluid path 348 fluidly couples the inner chamber 310 to a source of fluid supply 354 (for example, a source of compressed air supply).
    [0035] The unidirectional valve 350 allows the flow of fluid in the first direction from a fluid supply source 354 to an inner chamber 310 (for example, in a supply fluid it is provided in an inner chamber 310) and prevents the flow of fluid in the second direction from the inner chamber 310 to the vent 352 (for example, when fluid is removed or exhausted from the inner chamber 310). The second fluid path restrictor 346 substantially restricts or decreases the rate of fluid flow flowing through the second fluid path 344 when the fluid is removed or exhausted from the inner chamber 310 as described below. In other examples where restrictor 346 and one-way valve 350 are integrally formed with buffer 336, second port 330 and / or second and third fluid path 344 and 348 are not required.
    [0036] The inner chamber 310 receives pressurized fluid (e.g., compressed air) from a fluid supply source 354 to move pistons 306 and 308 in the first direction opposite the forces provided by induction elements 324 and 326 (for example example, an opening course). The inner chamber 310 can receive the pressurized fluid via the third fluid path 348 and the second port 330. For example, if the buffer 336 is blocking the first port 328, the pressurized fluid from a fluid supply source 354 does not. it can flow freely into the inner chamber 310 via the first fluid path 342. Instead, the unidirectional valve 350 moves to an open position via the supply fluid pressure to allow the pressurized fluid to flow between the supply source. fluid 354 and the inner chamber 310 via the third fluid path 348. The outer chambers 312 and 314 can be vented to the atmosphere via the passage 334 and the third port 332 so that the pressure of the inner chamber 310 needs only to exceed the forces exerted by the respective induction elements 324 and 326.
    [0037] When the pressurized fluid is removed from the inner chamber 310, the induction elements 324 and 326 tilt or move the pistons 306 and 308 towards the valve stem 322 (e.g., a closing stroke). As pistons 306 and 308 move towards valve stem 322, the fluid in the inner chamber 310 flows mainly between the first port 328 and the vent 352 via the first fluid path 342 to a first predetermined stroke length (for example , 80% of the course). When the buffer 336 is positioned away from the first port 328, the fluid in the inner chamber 310 flows mainly through the first fluid path 342 due to the increased flow resistance provided by the restrictor 346 in the second fluid path 344.
    [0038] However, pistons 306 and 308 move towards valve stem 322 over a second predetermined stroke length (for example, the remaining 20% of stroke), first piston 306 moves shock absorber 336 in one position that blocks the first port 328 to substantially restrict or prevent the flow of fluid through the first fluid path 342. As a result, fluid in the inner chamber 310 flows into the vent 352 primarily via the second port 330 and the second fluid path 344 As noted above, the one-way valve 350 prevents fluid flow from the inner chamber 310 to the vent 352 via the third fluid path 348. Instead, the fluid in the inner chamber 310 flows to the vent 352 via the second path fluid 344, where restrictor 346 restricts the rate of fluid flow through the second fluid path 344. When buffer 336 is blocking first port 328, fluids mainly flow through the second v fluid ia because the restrictor 346 provides a restriction through the second fluid path 344 which is less than the flow restriction between the inner chamber 310 and the first port 328 when the buffer 336 is blocking the first port 328. Thus, the speed of pistons 306 and 308 is reduced or damped (i.e., the movement of pistons 306 and 308 is decreased) over the second predetermined stroke length, providing partial stroke damping as pistons 306 and 308 move towards the valve shaft 322 (for example, a portion of an actuator closing stroke 300).
    [0039] Therefore, the first piston 306 moves the buffer 336 between a first position to allow fluid flow between the inner chamber 310 and the first port 328 and a second position to substantially restrict fluid flow between the inner chamber 310 and the first port 328 on only a portion of the stroke of actuator 300. In other words, buffer 336 allows fluid to flow through the first fluid path 342 as the fluid in the inner chamber 310 is removed or exhausted over a first predetermined portion of the stroke (e.g., 80% of a closing stroke) and substantially restricts the flow of fluid through the first fluid path 342 over a second predetermined portion of the stroke (e.g., 20% of a closing stroke). When the first port 328 is blocked by the buffer 336, the fluid in the inner chamber 310 flows to the vent 352 via the second fluid path 344 and the restrictor 346. In this way, the travel speed of the actuator is only reduced over the second predetermined stroke length (for example, one end of a closing stroke).
    [0040] Although not shown, the buffer 336 can be dimensioned so that in the first position the buffer 336 blocks the first port 328 along a larger portion (for example, 30%) or a smaller portion (for example, 10% ) of the full stroke of the rotary valve actuator 300. In yet other examples, the damping apparatus 302 may include a first damper disposed adjacent to a second damper to increase an amount or the duration of the partial stroke so that the first and second dampers lock the first port 328.
    [0041] FIGS. 4A-4D illustrate an example of damping apparatus 400 that can be used to implement, for example, the exemplary rotary valve actuator 300 of FIG. 3. FIG. 4A illustrates a partial sectional view of the example of compartment 304 of FIG. 3. In this example, the damping apparatus includes a damper 402 operatively coupled to a portion of the body 404 of a piston 406. Referring to FIGs. 4B-4D, shock absorber 402 is a cushion or bearing 408 coupled (for example, via interference fit or adjustment, etc.) in a slot or opening 410 of body portion 404 of piston 406. Pad 408 can be made of an elastomeric material, a plastic material, a metallic material, and / or any other suitable material. As shown in FIG. 4C, a first side 412 of the exemplary pad 408 includes protruding members 414 that fit tightly into slot 40 of the body portion 404. A second side 416 of the pad includes a surface 418 (e.g., a relatively smooth surface, a surface relatively rough) which is to restrict fluid flow through the first port 328 over only a portion of the actuator stroke as piston 406 moves towards the valve shaft 322 (for example, a portion of an actuator closing stroke 300).
    [0042] The operation of the exemplary damping apparatus 400 is similar to the function or operation of the exemplary damping apparatus 302 described above in relation to FIG. 3 and therefore will not be repeated. Instead, the interested reader is directed to the description described above in relation to FIG. 3.
    [0043] FIGS. 5A-5E illustrate another example of damping apparatus 500 described herein that can be used to implement, for example, the exemplary rotary valve actuator 300 of FIG. 3. As shown in FIG. 5A, the exemplary damping apparatus 500 includes a piston 502 disposed within housing 304 of actuator 300. Piston 502 includes a portion of the body or rack 504 operatively coupled to the drive shaft or pinion 320 of the valve shaft 322. In this example , the damping apparatus 500 includes a damper or locking element 506 operatively coupled (for example, via fitting, interference fit, etc.) for body portion 504 of piston 502.
    [0044] As shown more clearly in FIGs. 5C and 5D, the damper 506 is disposed (for example, via fitting, interference adjustment, a fastener, etc.) inside a slot or opening 508 of the body portion 504 of piston 502. Referring to FIGs. 5C and 5D, the damper 506 includes a flexible member or strip 510 coupled to the support 512 so that a portion of the flexible element can bend or deform. The flexible element 510 and / or the support 512 can be made of a metal material, an elastomeric material, a plastic material, and / or any other suitable material. As shown, the flexible element 510 comprises an elongated portion 514 and the base portion 516. The holder 512 includes slot 518 having a recess 520 which is larger than slot 518 (for example, to provide a T-shaped profile ) to interlacedly receive an end 522 (e.g., a T-shaped end) of the base portion 516. In other examples, the flexible element 510 and the support 512 can be integrally formed as a single piece or structure via, for example, overmoulding, injection molding, etc. In yet other examples, a second damper may be disposed within slot 508 of body portion 504 adjacent to damper 506 to increase the length of the stroke to which damper 506 restricts or prevents (i.e. blocks) the flow of fluid for the first port 328.
    [0045] FIG. 5B illustrates the damper 506 in a locked position. As shown, in operation, piston 502 moves damper 506 through a full stroke of actuator 300.
    [0046] However, damper 506 blocks first port 328 when piston 502 moves toward valve shaft 322 to substantially restrict fluid flow between inner chamber 310 and first port 328 along only the predetermined portion of the full stroke of actuator 300 (for example, 20% of a closing stroke) as piston 502 moves towards valve shaft 322. As noted above, the exemplary damping device 500 provides a flow restrictor (for example, flow restrictor 346) and one-way valve (e.g., exemplary one-way valve 350) of FIG. 3 integrally formed with the shock absorber 506.
    [0047] When the buffer 506 is in the locked position, fluid can be delivered to the inner chamber 310 via the first fluid path 342 and the first port 328. In particular, the pressurized fluid makes flexible element 506 (for example , the elongated portion 514) deform or move away from the first port 328 when pressurized fluid is supplied in the inner chamber 310 via the first path 342. Therefore, flexible element 506 provides a one-way valve to allow fluid flow within the inner chamber 310 when flexible member 506 is in the locking position and pressurized fluid is supplied via first path 346.
    [0048] As the pressurized fluid in the inner chamber 310 is removed or exhausted, piston 502 moves towards the valve shaft 322. As piston 502 moves towards the axis of valve 322, the fluid in the inner chamber 310 flows between first port 328 and vent 352 via first fluid path 342 for a first predetermined stroke length (e.g., 80% of stroke) without restriction (i.e., damper 506 is moving away from first port 328) .
    [0049] However, as piston 502 moves towards valve stem 322 over a second predetermined stroke length (for example, the remaining 20% of stroke), piston 502 moves shock absorber 506 in one position which blocks the first port 328. The pressure of the pressurized fluid in the inner chamber 310 causes the flexible element 510 to deform or move towards the first port 328 to substantially restrict (e.g., obstruct) fluid flow through the first fluid path 342. In this way, the buffer 506 reduces the fluid flow rate for the vent 352 via the first fluid path 342 when the buffer 506 is blocking or impeding the flow of fluid to the first port 328. In other words, the fluid flow between inner chamber 310 and first port 328 when buffer 506 is blocking first port 328 is less than the fluid flow between inner chamber 310 and first port 328 when buffer 502 is closed positioned away from the first port 328. In this way, the damping device 500 provides partial stroke damping as piston 502 and the second piston (not shown) move towards the valve shaft 322 (for example, a closed position of a valve operationally coupled to actuator 300.
    [0050] Additionally, the second port 330 and / or the second fluid path 348 shown in FIG. 3 is not necessary. Therefore, although not shown, in other examples, the exemplary damping apparatus 500 can be used to provide partial stroke damping for, for example, actuator 102 of FIGs. 1A and 1B. For example, piston 120 can be replaced with exemplary piston 502 having the exemplary damping apparatus 500. Therefore, in other examples, the actuator 102 of FIGs. 1A and 1B can be retrofitted with the exemplary damping device 500.
    [0051] FIGS. 6A and 6B illustrate another example of damping apparatus 600 described here. Referring to FIGs. 6A and 6B, the damping apparatus 600 includes a damper or locking element 602. In this example, damper 602 is a spring 604 coupled to a spring support or clip 606. Spring 604 is described as a spring that can be made from metal, plastic and / or any other suitable material. The spring support 606 is arranged inside a slot or opening 608 of a piston 610 via interference fit or adjustment to couple the spring 604 to piston 610.
    [0052] The spring support 606 includes a lower clip portion 612 which has a surface 614 that protrudes from the lower clip portion 612. Additionally, opening 608 is recessed and shaped (for example, tapered) to receive shape the spring support 606 is interwoven so that when disposed within opening 608, surface 614 engages with surface 616 of opening 608 so that the lower clip portion 612 is angled or compressed toward an upper clip portion 618 of the spring support 606 for coupling spring 604 to piston 610. Additionally, the upper clip portion 618 engages a surface 620 of piston 610 to orient or maintain the position of spring 604.
    [0053] The spring support 606 is arranged along a portion of the opening 608 so that the spring 604 blocks the first port 328 as piston 610 moves along the portion of a stroke of the actuator 300. For example, in operation, spring 604 blocks first door 328 along a partial or final portion of a closing stroke. The operation of the exemplary damping apparatus 600 is similar to the function or operation of the exemplary damping apparatus 500 described above in connection with FIGs. 5A-5E and therefore will not be repeated. Instead, the interested reader is directed to the description described above in connection with FIGS. 5A-5E.
    [0054] FIGS. 7A-7C illustrates the rotary valve actuator 700 having another example of damping apparatus 702 described here. In this example, actuator 700 is a double-acting actuator and includes a first piston 704 and a second piston 706 disposed within a compartment 708 to define an inner chamber 710 and its outer chamber 712 and 714.
    [0055] The compartment 708 includes a first port 716 and a second port 718 in fluid communication with the inner chamber 710 and a third port 720 fluidly coupled to the outer chambers 712 and 714 via a passage 722 (for example, integrally formed with compartment 708) and respective openings 724 and 726. Pistons 704 and 706 include respective body or rack portions 728 and 730 operably coupled to a valve shaft 732. Body portion 728 of first piston 704 includes an opening 734 for engaging fluidly the first port 716 to the inner chamber 710 when the first piston 704 is positioned inside the compartment 708 so that the opening 734 is aligned with the first port 716 (for example, when the first piston 704 is in a first position or in closed position shown in Figure 7A).
    [0056] In this example, the damping device 702 includes a first fluid path 736 fluidly coupled to the inner chamber 710 via the first port 716 and the second fluid path 738 fluidly coupled to the inner chamber 710 via the second port 718. The first fluid path 736 fluidly couples the inner chamber 710 to a fluid supply source 737 and a vent 739. The second fluid path 738 fluidly couples the inner chamber 710 to the vent 739 and includes a flow restrictor 740 to reduce or restrict the rate of fluid flow through the second fluid path 738. More specifically, fluid flow through the second fluid path 738 when the damping device 702 is blocking fluid flow to the first port 716 is less than the flow of fluid between the inner chamber 710 and the first port 716 when the damping apparatus 702 is not blocking the flow of fluid to the first port 716.
    [0057] Referring also to FIGs. 7B and 7C, in this example, the damping device 702 includes a damper or a locking element 742 (e.g., a flow control device) coupled to the first piston 704 so that damper 742 is aligned with the opening 734 of the first piston 704. The exemplary damper 742 includes a body or compartment 744 having a flap or movable element 746. As shown, the movable element 746 is rotatably coupled to compartment 744. an induction element 748 (e.g., a spring) tilts the element moving 746 towards compartment 744 so that buffer 742 is in a closed position as shown in FIG. 7B. FIG. 7C illustrates buffer 742 in an open position. When coupled to the first piston 704, a first face 750 of the compartment 744 facing the first door 716 and a second 752 of the compartment 744 facing the opening 734 of the first piston 704.
    [0058] In operation, the inner chamber 710 receives pressurized fluid from a fluid supply source 737 via the first fluid path 736. If the first piston 704 is in the position shown in FIG. 7A, the fluid pressurized from a fluid supply source 737 causes the movable element 746 to move to the open position as shown in FIG. 7C to allow fluid flow to the inner chamber 710 via the first port 716 and the opening 734 of the first piston 704. The pressurized fluid in the inner chamber 710 causes the pistons 704 and 706 to move in a straight motion in a direction away from the valve shaft 732, causing valve shaft 732 to rotate in the first direction (for example, counterclockwise). As the first piston 704 moves away from the valve shaft 732, the buffer 742 moves away from the first port 716 and the pressurized fluid continues to flow into the inner chamber 710 via the first fluid path 736 and the first port 716 (for example around the body portions 728 and 730 of the respective pistons 704 and 706). The fluid in the external chambers 712 and 714 is removed or vented via the respective openings 724 and 726 and the passage 722 as pistons 704 and 706 move towards respective surfaces 754 and 756 of compartment 708.
    [0059] Pistons 704 and 706 cause valve shaft 732 to rotate in the second direction (for example, clockwise) when pistons 704 and 706 move towards valve shaft 732. To move pistons 704 and 706 in towards the valve shaft 732, the pressurized fluid is supplied in the external chambers 712 and 714 via the third port 720 and the passage 722, and the pressurized fluid in the internal chamber 710 is removed or exhausted. As pistons 704 and 706 move towards the valve shaft 732, the pressurized fluid in the inner chamber 710 flows to, for example, the atmosphere via the first port 716 along the portion of the piston stroke for which the damper 742 does not. aligns with or blocks the first port 716. Due to flow restrictor 740 in the second fluid path 738, the fluid in the inner chamber 710 flows mainly between the inner chamber 710 and the first port 716 because it has less fluid flow resistance in the first fluid path 736 when buffer 742 is not blocking first port 716.
    [0060] As the pistons 704 and 706 move towards the valve shaft 732 and the damper 742 aligned with or blocks the first port 716, the pressurized fluid in the inner chamber 710 acts on the second face 752 of the moving element 746 and makes the element mobile 746 to move to the closed position shown in FIG. 7C. Therefore, in the closed position, the buffer 742 substantially restricts or prevents fluid flow through the first port 716. As a result, pressurized fluid in the inner chamber 710 is removed or vented mainly via the second port 718 when the buffer 742 blocks the first port 716 as the pistons 704 and 706 move towards the valve shaft 732. With the buffer 742 in the closed position, the flow restrictor 740 restricts the fluid flow rate through the second fluid path 738. More specifically, fluid flow through the second fluid path 738 when the buffer 742 is blocking fluid flow to the first port 716 is less than the fluid flow between the inner chamber 710 and the first port 716 when the buffer 742 is spaced apart or not blocking the first port 716.
    [0061] Therefore, in operation, the pressurized fluid in the inner chamber 710 provides a cushion effect to reduce the speed of the pistons 704 and 706 as the damper 742 moves and aligned with the first port 716 along only the partial stroke of the actuator 700. For example, this partial stroke can be 20 percent of a closing stroke. Also, when the buffer 742 is misaligned with or blocking the first port 716, the buffer 742 provides the one-way valve to allow fluid flow into the inner chamber 710 via the first port 716 and substantially prevent fluid flow from the inner chamber 710 for ventilation via the first port 716. In other words, as noted above, the exemplary damping apparatus 702 provides a one-way valve function that is integrally formed with damper 742.
    [0062] FIG. 8 illustrates another example of damping apparatus 800 described here that can be used to implement the rotary valve actuator 700 of FIG. 7A. In this example, actuator 700 includes a piston 802 having an orifice 804 that is substantially perpendicular to an opening 805 of the piston 802. Opening 805 fluidly couples first port 716 to inner chamber 710 when opening 805 aligned with first port 716 .
    [0063] In this example, the damping apparatus 800 includes a damper or rod 806 (e.g., a flow control assembly) slidably disposed within orifice 804 of piston 802. an induction element 808 is disposed within orifice 804 between a spring seat 810 and stem 806 to induce stem 806 towards a surface 812 of piston 802. a housing 814 having an opening (not shown) therethrough is coupled within opening 805 of piston 802 and fluidly couples the first door 716 and the opening 805 when the opening is misaligned with the first door 716.
    [0064] In operation, the pressurized fluid is supplied in the inner chamber 710 via the first port 716 and the opening 734. When the opening of compartment 814 aligned with the first port 716, compartment 814 directs the pressurized fluid into the opening 805. The pressurized fluid fits or acts on the conical surface or edge 816 of stem 806, thereby causing stem 806 to move in a direction opposite to the force exerted by induction element 808. Piston 802 moves towards SURFACE 754 as the inner chamber 710 receives pressurized fluid. The pressurized fluid continues to flow through the first port 716 when the piston 802 and therefore the housing 814 moves away from the first port 716.
    [0065] To move the piston 802 towards the valve shaft 732 (for example, a closed position), pressurized fluid is supplied in the outer chambers 712 and 714 via the third port 720 and the passage 722, and the pressurized fluid in the inner chamber 710 is removed or exhausted. As piston 802 moves towards the valve shaft 732, the pressurized fluid in the inner chamber 710 flows to, for example, the atmosphere via the first port 716 and the first fluid path 736 over a portion of the travel of the actuator 700 in which the compartment 814 (and the stem 806) is moving away (for example, does not line up with or block) the first port 716.
    [0066] As piston 802 moves towards valve shaft 732 and compartment 814 aligned with the first port 716, the face or surface 818 of stem 806 prevents fluid flow between the inner chamber 710 and the first port 716 Instead, the pressurized fluid in the inner chamber 710 is removed or vented via the second port 718 along a portion of the stroke of actuator 700 to which stem 806 blocks the first port 716 as piston 802 moves towards the valve shaft 732. Flow restrictor 740 restricts the flow of fluid through the second fluid path 738 so that the flow of fluid through the second fluid path 738 is less than the flow of fluid between the inner chamber 710 and the first port 716 when compartment 814 is moving away or not blocking the first port 716. As a result, the pressurized fluid in the inner chamber 710 is vented at a reduced or decreased rate and provides the cushioning or cushioning effect p to reduce the speed (i.e., decrease movement) of piston 802 as housing 814 and stem 806 align with or block fluid flow to first port 716 over only a portion of the travel of actuator 700.
    [0067] FIGS. 9-17 illustrate another example of the damping apparatus described here that can be used to provide partial stroke damping to, for example, actuator 102 of FIGs. 1A and 1B. In yet another example, the actuator 102 of FIGs. 1A and 1B can be retrofitted with the exemplary damping apparatus 900-1600 described in FIGS. 9-16, respectively. For example, pistons 120 and 122 of actuator 102 of FIGs. 1 A and 1B can be replaced with the exemplary pistons and damping apparatus described here in connection with FIGS. 9-16. In addition, the damping apparatus described in FIGS. 9-16 do not need a second fluid circuit or flow path (for example, the second fluid circuit 340 and 738 of FIGS. 3A and 7A, respectively) or a second port (for example, second ports 330 and 718 of Figures 3A and 7A, respectively) described above in connection with the exemplary actuators 300 and 700.
    [0068] FIG. 9 illustrates another example of the cushioning apparatus 900 described here. In this example, a first piston 902 includes a first recessed orifice 904 that coaxially aligned with a first orifice 906 of a second piston 908. Additionally, as shown, the first piston 902 includes a second orifice 910 that coaxially aligned with a second recessed orifice 912 of the second piston 908. A first induction element 914 is disposed within the first orifice 906 of the second piston 908 and a second induction element 916 is disposed within the second orifice 910 of the first piston 902.
    [0069] In operation, as pistons 902 and 908 move away from each other (for example, an open position), the damping device 900 does not provide damping. In other words, the first recessed hole 904 is spaced apart or does not engage the first end 918 of the first induction element 914 and the second recessed hole 912 is spaced apart or does not engage the first end 920 of the second induction element 916. Also, the damping apparatus 900 does not provide damping for a first portion of the stroke for which the first and second pistons 902 and 908 are moved towards each other and when the first piston does not engage the first induction element 914 and the second piston 908 does not engage the second induction element 916.
    [0070] The first recessed hole 904 engages the first end 918 of the first induction element 914 and the second recessed hole 912 engages the first end 920 of the second induction element 916 to activate the damping apparatus 900 over only a portion of the stroke for which the first piston 902 moves towards the second piston 908. The induction elements 914 and 916 exert forces on the respective pistons 902 and 908 which increases significantly when pistons 902 and 908 move towards each other. The induction elements 914 and 916 exert forces that increase as the induction elements 914 and 916 compress the pistons 902 and 908 move towards each other (for example, to a closed position). In turn, the forces exerted by induction elements 914 and 916 increase significantly to reduce the speed of pistons 902 and 908 as pistons 902 and 908 move towards each other. Therefore, the induction elements 914 and 916 decreasing more and more the speed of the pistons 902 and 908 as the pistons move close to each other.
    [0071] Induction elements 914 and 916 can have a linear or constant spring rate or a non-linear or constant spring rate. As shown in this example, induction elements 914 and 916 are coiled spring. However, exemplary induction elements 914 and 916 are not limited to spiral springs as shown in FIG. 9 and can be any suitable induction elements. For example, referring to FIG. 10 the damping apparatus 1000 may instead be an induction element 1002 such as, for example, a bellows spring, a spring-type seal bellows, a shock absorber, a mechanical seal, a pneumatic spring, etc. and / or any other suitable induction element.
    [0072] In yet other examples, the damping apparatus may be non-mechanical induction elements such as, for example, the damping apparatus 1100 and 1200 of FIGs. 11 and 12, respectively.
    [0073] Referring to FIG. 11, the damping apparatus 1100 includes a pneumatic spring or damper 1102 coupled to a surface 1104 of a first piston 1106 and extending or projecting the surface 1104 towards a second piston 1108. The second piston 1108 includes a portion of the body 1110 having an orifice 1112 coaxially aligned with, and slidably sized to receive, pneumatic spring 1102. Pneumatic spring 1102 has a cylindrical shaped body 1114 that includes channels or fluid paths 1116 to fluidly couple the first end 1118 of the body 1114 and the second end 1120 of body 1114. When coupled within orifice 1112, pneumatic spring 1102 and orifice 1112 defines a fluid chamber 1122.
    [0074] In operation, the internal chamber 126 of actuator 102 receives pressurized fluid to move pistons 1106 and 1108 away from each other (for example, to an open position). When the air spring 1102 is spaced away from the orifice 1112, the orifice 1112 receives pressurized fluid from the inner chamber 126 of the actuator 102.
    [0075] Damping device 1100 does not provide damping when air spring 1102 is spaced apart or does not engage second piston 1108. Also, damping device 1100 does not provide damping for a first portion of the stroke for which the first and second pistons 1106 and 1108 are moved towards each other and when the air spring 1102 does not engage (that is, it is not received by) orifice 1112 of the second piston 1108. Instead, the first piston 1106 moves the air spring 1102 inside orifice 1112 to activate the damping device 1100 for only a second portion of the stroke. Specifically, the first piston 1104 moves the air spring 1102 into the orifice 1112 between a first position and a second position towards a surface 1124 of the orifice 1112 to compress the fluid in the chamber 1122. As a result, the fluid pressure in the chamber 1122 increases to provide significantly greater resistance or force in one direction to the first piston 1106.
    [0076] Also, the fluid in chamber 1122 drains into the inner chamber 126 via channels 1116 of air spring 1100. Channels 1116 are relatively small in diameter to substantially restrict fluid flow between first end 1118 (e.g., chamber 1122) and the second end 1120 (for example, the inner chamber 126) of the air spring 1100. Therefore, the air spring 1102 provides the cushioning or cushion effect to reduce the speed (i.e., decrease movement) of the first piston 1106 during only a portion of the stroke of the actuator 102 for which the air spring 1102 moves within the orifice 1112, thereby providing partial stroke damping. A plug 1126 can be coupled to at least one of the channels 1116 to vary the drain rate between chamber 1122 and inner chamber 126. Additionally, pneumatic spring 1102 may include a seal 1128 to prevent leakage of fluid into the body portion 1114 of air spring 1102. In this example, second piston 1106 also includes damping apparatus 1100 to provide additional damping (i.e., to decrease movement) over only a portion of the stroke.
    [0077] Referring to FIG. 12, the exemplary damping apparatus 1200 is also a pneumatic spring or damper 1202 similar to the pneumatic spring 1102 of FIG. 11. However, pneumatic spring 1202 of FIG. 12 includes an adjustable member 1204 for adjusting or varying the damping to be provided by the damping apparatus 1200. The adjustable member 1204 (for example, a screw clamp) can be adjusted to move or position a cylindrical body part 1206 of the pneumatic spring 1202 with respect to a surface 1208 of a first piston 1210. For example, the adjustable member 1204 can be adjusted to position a portion of the body 1206 later away from the second surface 1208 of the first piston 1210. Thus, the portion of the body 1206 of pneumatic spring 1202 will move close to a surface 1216 of orifice 1212 when the first piston 1210 and a second piston 1214 move towards each other and the pneumatic spring 1202 is received by orifice 1212. As a result, the fluid within the orifice 1212 is compressed to provide a force towards the first piston 1210 which is v greater than a force provided by the compressed fluid in orifice 1212 when the body portion 1206 is positioned close to or adjacent the surface 1208 of the first piston 1210 as shown, for example, in FIG. 12. Thus, adjusting the position of body portion 1206 within orifice 1212 varies the rate of fluid drainage between orifice 1212 and inner chamber 126 of actuator 102 via channels 1218 of body portion 1206. Additionally, as a result, the amount or length of the stroke portion for which the damping apparatus 1200 provides damping can also be adjusted because the body portion 1206 can be positioned to move within orifice 1212 a greater distance towards surface 1216 than, for example, the position shown in FIG. 12. In this example, the second piston 1214 also includes the damping apparatus 1200 to provide additional damping over only a portion of the stroke.
    [0078] FIG. 13 illustrates another example of damping apparatus 1300 described here that can be used to implement, for example, the actuator 102 of FIGs. 1 A and 1B. In this example, the exemplary damping apparatus 1300 is disposed within an orifice 1302 of a first piston 1304. a second piston 1306 may also include a damping apparatus 1300. The damping apparatus 1300 includes a slidingly coupled body or cylinder 1308 or disposed within orifice 1302. Cylinder 1308 includes an orifice or chamber 1310 for slidably receiving rod 1312 (e.g., a piston) at a first end 1311 of cylinder 1308 and has a second end 1320 protruding from the first orifice 1302 of the first piston 1304.
    [0079] Cylinder 1308 includes an opening 1314 to form a fluid path 1316 between chamber 1310 and inner chamber 126 when a surface 1318 of second piston 1306 is spaced away from the second end 1320 of cylinder 1308. Also, the cylinder 1308 includes openings 1322 adjacent the second end 1320 to fluidly couple chamber 1310 and inner chamber 126 of actuator 102 when SURFACE 1318 of second piston 1306 engages second end 1320 of cylinder 1308. The diameter of openings 1322 is smaller than the diameter of the fluid path 1316, which is smaller than the diameter of the chamber 1310. an induction element 1324 is disposed within the orifice 1302 to induce the cylinder 1308 away from the stem 1312.
    [0080] In operation, chamber 1310 receives pressurized fluid via fluid path 1316 when pressurized fluid is supplied to inner chamber 126 of actuator 102. When the pressurized fluid in inner chamber 126 is removed or exhausted, pistons 1304 and 1306 moves towards each other. The damping apparatus 1300 does not provide damping for a first portion of the stroke to which the second piston 1306 is moved towards the first piston 1304 and to which the second piston 306 does not engage the second end 1320 of cylinder 1308. Instead furthermore, the damping apparatus 1300 provides damping only for a second portion of the stroke to which the second piston 1306 engages cylinder 1308.
    [0081] More specifically, as the second piston 1306 moves towards the first piston 1304, the surface 1318 of the second piston 1306 engages the second end 1320 of cylinder 1308 to activate the damping apparatus 1300. When engaged, the second piston 1306 causes cylinder 1308 to move towards stem 1312. As cylinder 1308 moves towards stem 1312, the fluid pressure in chamber 1310 increases to provide significantly greater resistance or force in one direction towards second piston 1306.
    [0082] Additionally, the surface 1318 of the second piston 1306 substantially restricts the flow of fluid between the second end 1320 of the fluid path 1316 and the inner chamber 126 when the surface 1318 engages the second end 1320. As a result, the stem 1312 forces the fluid in the chamber 1310 to flow into the inner chamber 126 via the fluid path 1316 and the openings 1322.
    [0083] As noted above, because the diameter of the fluid path 1316 is smaller than the diameter of the chamber 1310 and the diameter of the openings 1322 is less than the diameter of the fluid path 1316, the fluid flow to the inner chamber 126 is substantially restricted through the openings 1322. In other words, the flow of fluid between the inner chamber 126 and the chamber 1310 via the openings 1322 (when the surface 1318 of the second piston 1306 fits the second end 1320 of cylinder 1308) is less than the flow of fluid between flow between the inner chamber 126 and the chamber 1310 via the fluid path 1316 when the surface 1318 is spaced away from the second end 1320.
    [0084] Therefore, the pressurized fluid in chamber 1310 provides the cushioning or cushioning effect to decrease the speed of the first piston 1304 only during the portion of the stroke to which the second piston 1306 fits the cylinder 1308. In other words, the pressure of the increased fluid in the chamber 1310 provides damping over only a portion of the stroke of actuator 102 for which the second piston 1306 engages the second end 1320 of cylinder 1308. The damping apparatus 1300 of the second piston 1306 also provides partial stroke damping as the second piston 1306 moves towards the first piston 1304.
    [0085] FIG. 14 illustrates yet another example of damping apparatus 1400 described here that can be used to implement, for example, the exemplary rotary valve actuator 102 of FIGS. 1A and 1B. In this example, a first piston 1402 includes a body portion 1404 (e.g., a rack portion) having an orifice 1406 for receiving the damping apparatus 1400. As shown, the damping apparatus 1400 includes the draining rod or piston 1408 , an induction element 1410, and a spring seat 1412. Induction element 1410 tilts stem 1408 toward a shoulder 1414 of body portion 1404 formed by orifice 1406. A surface 1416 of a second piston 1418 fits a end 420 of the stem 1408 to activate the damping apparatus 1400. The stem 1408 includes a fluid path 1422 for fluidly coupling the inner chamber 126 of the actuator 102 and a chamber 1424 defined by the orifice 1406 and the stem 1408.
    [0086] In operation, the inner chamber 126 of the actuator 102 receives the pressurized fluid to move the pistons 1402 and 1418 away from each other. Chamber 1424 receives pressurized fluid from inner chamber 126 via fluid path 1422. When the pressurized fluid is removed or exhausted from inner chamber 126, pistons 1402 and 1418 move towards each other. The damping apparatus 1400 does not provide damping for a first portion of the stroke for which pistons 1402 and 1418 are moved towards each other and when the surface 1416 of second piston 1418 does not engage stem 1408. Instead, damping apparatus 1400 provides damping for only a second portion of the stroke to which second piston 1418 engages stem 1408. Also, the pressurized fluid in chamber 1424 flows into inner chamber 126 via fluid path 1422 substantially without restriction when the second piston 1418 is spaced away from the stem 1408.
    [0087] For the second portion of the stroke, the surface 1416 of the second piston 1418 engages the end 1420 of the stem 1408 to activate the damping apparatus 1400. The second piston 1418 engages the end 1420 to make the stem 1408 move between a first position and a second position in a direction towards spring seat 1412. in turn, stem 1408 compresses the fluid in chamber 1424 and causes the fluid pressure in chamber 1424 to increase. Also, the surface 1416 of the second piston 1418 and the end 1420 of the stem 1408 do not wrap in a sealed manner, thus allowing the fluid in the chamber 1424 to drain or flow into the inner chamber 126 via the fluid path 1422 when the second piston 1418 engages the rod 1408. Also, although not shown, end 1420 of rod 1408 may include a channel or slot to allow fluid flow between chamber 424 and inner chamber 126 when the second piston 1418 engages rod 1408. However, this flow of the inner chamber 126 via the fluid path 1422 is substantially restricted or reduced due to the surface 1416 of the second piston 1418 being engaged with the opening of the fluid path 1422 at an end 1420 of the stem 1408.
    [0088] Therefore, as the second piston 1418 makes the stem 1408 to move toward a spring seat 1412, the fluid in chamber 1424 drains into inner chamber 126. As a result, the pressurized fluid in chamber 1424 increases over of a portion of the stroke to which the second piston 1418 engages the stem 1408. Therefore, the damping apparatus 1400 provides the damping or pad effect to reduce the speed of the second piston 1418 during only a portion of the stroke of the actuator 102 to which second piston 1418 engages stem 1408, thereby providing partial stroke damping.
    [0089] FIG. 15 illustrates yet another example of the cushioning apparatus 1500 described here. In this example, the damping apparatus 1500 is arranged within a hole 1502 of a piston 1504 to define a chamber 1506. The damping apparatus 1500 includes a movable element or rod 1508, an induction element 1510, and a valve assembly 1512 The induction element 1510 is arranged between the movable element 1508 and the valve assembly 1512 to induce the movable element 1508 towards a shoulder 1514 formed by the orifice 1502. The movable element 1508 includes a stem portion 1516 that protrudes from orifice 1502 and which must be fitted by a second piston (not shown). Valve assembly 1512 includes a first fluid path 1518 having a one-way valve 1520 (e.g., a check valve) and the second fluid path 1522 having a flow restrictor 1524. Flow restrictor 1524 can be adjustable to increase or reduces the restriction or rate of fluid flow through the second fluid path 1522.
    [0090] In operation, chamber 1506 receives pressurized fluid via an inlet 1526 of the first fluid path 1518. For example, the first fluid path 1518 can be fluidly coupled to an external chamber or the port of an actuator such as, for example, the outer chamber 130 and the path 144 of the exemplary rotary valve actuator 102 of FIGs. 1A and 1 B. The damping apparatus 1500 does not provide damping for a first portion of the stroke to which the second piston is moved towards piston 1504 and when the second piston does not engage moving element 1508. Instead, the damping apparatus 1500 is activated or provides damping on only a second portion of the stroke as the second piston moves towards piston 1504 and engages rod portion 1516 of moving element 1508 to make moving element 1508 to move towards valve assembly 1512. As the mobile element 1508 moves towards the valve assembly 1512, the mobile element 1508 compresses or reduces the volume of the fluid in the chamber 1506, thereby causing the fluid pressure in the chamber 1506 to increase.
    [0091] Additionally, the one-way valve 1520 moves towards a seating surface 1528 to prevent fluid flow from the chamber 1506 to the inlet 1526 via the first fluid path 1518. Therefore, the moving element 1508 moves in a straight motion towards the valve assembly 1512, the fluid in chamber 1506 flows through the second fluid path 1522. The flow restrictor 1524 substantially restricts the flow of fluid through the second fluid path 1522. As a result, the fluid pressurized in chamber 1506 provides the cushioning or cushioning effect to slow piston 1504 during the second portion of the stroke to which the second piston engages rod portion 1516 of moving element 1508.
    [0092] FIG. 16 illustrates yet another example of damping apparatus 1600 described here that can be used to implement or retrofit, for example, the rotary valve actuator 102 of FIGs. 1A and 1B to provide partial stroke damping. In this example, a first piston 1602 includes a body portion 1604 (e.g., a rack portion) having a first orifice 1606 for slidably receiving rod 1608. The stem 1608 includes a first portion 1610 disposed within the first orifice 1606 and a second portion 1612 protruding from an end614 of the body portion
    [0093] 1604. The first orifice 1606 and the first portion 1610 of stem 1608 define a chamber 1616 for holding a fluid such as, for example, a viscous fluid. Chamber 1616 is filled with fluid via an access port 1618. A plug (not shown) is coupled to access port 1618 and stem 1608 includes seal 1620 to fluidly seal a chamber 1616 and prevent leakage of fluid between the chamber 1616 and an inner chamber (for example, inner chamber 126) of an actuator (for example, actuator 102). A surface 1622 of a second piston 1624 engages the second portion 1612 of the stem 1608 to activate the damping apparatus 1600 over only a portion of the stroke to which the second piston 1624 engages the stem 1608.
    [0094] In operation, the first piston 1602 and the second piston 1624 move in a first position or an open stroke and the second direction or opposite the first direction or a closing stroke. The pistons 1602 and 1624 move away from each other (for example, an open position), the damping device 1600 does not provide damping and the volume of fluid in the chamber 1616 causes the rod 1608 to move away from a surface 1626 of the first orifice 1606. Also, the damping device 1600 does not provide damping for a first portion of the stroke to which the second piston 1624 is moved towards the first piston 1602 and when the second piston 1624 does not engage the second portion 1612 of the rod 1608.
    [0095] Instead, the damping apparatus 1 00 is activated or provides damping over only a second portion of the stroke as the second piston 1624 moves towards piston 1602 and surface 1622 fits the second portion 1612 of stem 1608 to cause the stem 1608 to move towards the surface 1626 of the first orifice 1606. As the stem 1608 contacts and moves towards the surface 1626, the first portion 1610 of the stem 1608 compresses or reduces the volume of the fluid in the chamber 1616, thereby causing the fluid pressure in the 1616 chamber to increase. Increasing fluid pressure in chamber 1616 provides a cushion effect to slow pistons 1602 and 1624 as pistons 1602 and 1624 move toward each other and the first portion 1610 of stem 1608 moves toward surface 1626 over a portion of a stroke (e.g., a portion of the closing stroke), thereby providing partial stroke damping.
    [0096] FIG. 17 illustrates another example of damping apparatus 1700 described here that provides partial stroke damping to a rotary valve actuator 1702. In this example, damping apparatus 1700 includes viscosity damper 1704 which is mounted in a housing 1706 of actuator 1702. The viscosity damper 1704 includes a coating 1708 having a viscous fluid therein and a sliding piston member 1710. Actuator 1702 includes a valve shaft 1712 having a cam 1714 coupled to valve shaft 1712 to fit sliding piston member 1710. In this example, the meat 1714 has an arcuate or curved surface that includes an edge or surface 1716 to fit the piston member 1710 of the viscosity damper 1704. The actuator 1702 includes pistons (not shown) with rack portions (not shown) that fit on an axis drive or pinion (not shown) of the 1712 valve shaft to rotate the 1712 valve shaft.
    [0097] In operation, the pistons (not shown) reciprocate inside compartment 1706 in a straight motion to rotate the 1712 valve shaft in the first direction (for example, counterclockwise) or an opening stroke and the second direction (for clockwise) or a closing course. As the pistons move towards the valve shaft 1712, the flesh 1714 rotates with the valve shaft 1712 and engages the piston member 1710 of the viscosity damper 1704 for only a portion of the stroke of the actuator 1702. The viscous fluid of the damper viscosity 1704 provides the cushion effect to reduce the speed of the pistons as the pistons move towards each other during the portion of a stroke to which the flesh 1714 engages the piston member 1710 of the viscosity damper 1704, thereby providing partial stroke damping.
    [0098] Although certain examples of apparatus and articles of manufacture have been described here, the scope of coverage of this patent is not limited by them. On the contrary, this patent covers all apparatus and articles of manufacture reasonably within the scope of the claims attached literally or under the doctrine of equivalents.
    权利要求:
    Claims (9)
    [0001]
    1. A rotary valve actuator (300), comprising: a housing (304) containing a first piston (306, 406) and a second piston (308) opposite the first piston; an inner chamber (310) defined in the housing (304) between the first piston (306) and the second piston (308), in which the pistons (304, 306) must move in opposite directions to rotate an axis (320) of the rotary valve actuator (300); and a damping apparatus (302) operatively arranged to slow the movement of the pistons (304, 306) for only part of a stroke of the rotary valve actuator (300), characterized by the fact that the damping apparatus (302) comprises: a first port (328) and a second port (330) in fluid communication with the inner chamber (310); a first fluid circuit (338) and a second fluid circuit (340), the first fluid circuit (338) including a first fluid path (342) fluidly connecting the first port (328) and the inner chamber (310) to a fan (352) and the second fluid circuit (340) including a second fluid path (344) fluidly connecting the second port (330) and the inner chamber (310); and a locking element (336) operatively coupled to the first piston (306), wherein the first piston (306) causes the locking element (336) to move between a first position to allow fluid to flow between the inner chamber (310) and the fan (352) through the first port (328) and a second position to substantially restrict the flow of fluid between the inner chamber (310) and the fan (352) through the first port (328) on the portion the travel of the rotary valve actuator (300); and the second fluid circuit (340) includes a fluid flow restrictor (346) so that the fluid flow through the second fluid path (344) when the locking element (336) is in the second position is less than the flow of fluid between the inner chamber (310) and the first port (328) when the locking element (336) is in the first position, so that when the locking element (336) is in the first position, the fluid in the inner chamber (310) flows first through the first fluid path (342) due to the increased flow resistance provided by the fluid flow restrictor (346) and when the locking element (336) is in the second position, the fluid in the chamber internal (310) is directed to flow mainly through the second port (330) and the second fluid path (344).
    [0002]
    2. Rotary valve actuator (300) according to claim 1, characterized by the fact that it also comprises a third fluid path (348) fluidly coupled to the second port (330) and having a unidirectional valve (350) arranged for allow fluid flow through the third fluid path in a first direction to the inner chamber (310) and restrict fluid flow through the third fluid path in a second direction out of the inner chamber.
    [0003]
    3. Rotary valve actuator (300) according to claim 2, characterized in that the second fluid path (344) fluidly couples the inner chamber (310) to the fan (352) when the locking element (336 ) is in the second position, and the third fluid path (348) fluidly couples the inner chamber (310) to a fluid supply source.
    [0004]
    Rotary valve actuator (300) according to any one of claims 1 to 3, characterized in that the first piston (306) includes a first body portion (316, 404) which fits the shaft (320) , and wherein the locking element (336) is coupled to the first body portion (316) of the first piston.
    [0005]
    5. Rotary valve actuator (300) according to claim 4, characterized in that the first body portion (404) has an opening (410) for receiving the locking element.
    [0006]
    6. Rotary valve actuator (300) according to claim 5, characterized in that the locking element (336) is coupled within the opening (410) of the first piston through an interference fitting.
    [0007]
    Rotating valve actuator (300) according to any one of claims 1 to 6, characterized in that the locking element (336) comprises a pad (408).
    [0008]
    Rotary valve actuator (300) according to any one of claims 1 to 6, characterized in that the locking element (336) comprises a flexible element (510) coupled to a handle (512).
    [0009]
    A rotary valve actuator (300) according to claim 8, characterized in that the flexible element (510) comprises a spring (604).
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    同族专利:
    公开号 | 公开日
    WO2011028663A2|2011-03-10|
    WO2011028663A3|2011-05-12|
    CN102483179B|2014-12-17|
    JP2013504025A|2013-02-04|
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    CA2955431C|2019-04-30|
    CN102483179A|2012-05-30|
    US8567752B2|2013-10-29|
    CA2955431A1|2011-03-10|
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    法律状态:
    2019-01-08| B06F| Objections, documents and/or translations needed after an examination request according art. 34 industrial property law|
    2019-08-06| B06U| Preliminary requirement: requests with searches performed by other patent offices: suspension of the patent application procedure|
    2020-03-17| B09A| Decision: intention to grant|
    2020-08-11| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 30/08/2010, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    US12/552814|2009-09-02|
    US12/552,814|US8567752B2|2009-09-02|2009-09-02|Rotary valve actuators having partial stroke damping apparatus|
    PCT/US2010/047151|WO2011028663A2|2009-09-02|2010-08-30|Rotary valve actuators having partial stroke damping apparatus|
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