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    • 专利摘要:
    The cooling and lubricating system (1) is provided for a piston sealing device (2) for a piston (3) having a fixed skirt (7) and a sliding skirt (12) interconnected by a connection inter-skirt mechanism (13) for axially compressing an expandable continuous segment (15) under the action of a slidable skirt spring (20), said system (1) adding to said device (2) a sliding skirt ring abutment (21) so as to interpose between the fixed skirt (7) and the extensible continuous segment (15) a flow valve (22) traversed by the inter-skirt mechanical connection (13), said valve (22) being at rest maintained remote from the fixed skirt (7) by a valve return spring (30) on the one hand, and comprising a flow calibration orifice (27) on the other hand.
    公开号:FR3046205A1
    申请号:FR1563316
    申请日:2015-12-24
    公开日:2017-06-30
    发明作者:Vianney Rabhi
    申请人:Vianney Rabhi；
    IPC主号:
    专利说明:

    COOLING AND LUBRICATION SYSTEM FOR PISTON SEALING DEVICE
    The present invention relates to a cooling and lubrication system for a piston sealing device. Said invention is an improvement of the piston sealing device subject of the patent application FR 3009037 dated July 23, 2013 belonging to the applicant. Said device is particularly suitable for any piston operating under high pressure.
    The piston sealing device according to the patent application FR 3009037 is provided for a piston operating in a cylinder whose one end is closed by a fluid chamber, said piston comprising at least one piston head which comprises at least a fixed skirt, said head having on the one hand a plunger bearing face for exerting a force on any mechanical, hydraulic or pneumatic transmission means and, on the other hand, a compression face opening into the fluid chamber and able to receive the pressure of a fluid.
    Still according to the patent application FR 3009037, the piston sealing device comprises a sliding skirt of cylindrical shape housed in a cylinder with a small clearance. Said skirt is further placed in the extension of the piston head on the side of the piston. compression side and in the axis of said head.
    It is noted that said sliding skirt is connected to said head by an inter-skirt mechanical connection which allows it to move in longitudinal translation relative to said head while a pressure transmission channel arranged inside the sliding skirt crosses the latter from side to side in the axial direction. The invention of the patent application FR 3009037 is also characterized by an extensible continuous ring-shaped continuous segment which is interposed between the fixed skirt and the sliding skirt. Said segment comprises an internal cylindrical segment face subjected to the pressure of the fluid via the pressure transmission channel, an outer cylindrical segment face that can come into contact with the cylinder, a fixed skirt-side segment axial face maintained directly or indirectly by sealing contact with the fixed skirt and an axial side segment sliding skirt side directly or indirectly in sealing contact with the sliding skirt.
    Finally, the invention relating to the patent application FR 3009037 is also characterized by a sliding skirt spring which tends to bring the sliding skirt closer to the fixed skirt and compress axially the continuous segment extensible or at least, which prohibits said slippery skirt to move away from the fixed skirt like a stop. When reading patent FR 3009037, it is understood that the maximum leakage rate of fluid flowing between the piston and the cylinder is found when the pressure in the fluid chamber is sufficiently high to maximize the flow of fluid passing through. in the game left between the sliding skirt and the cylinder, but not yet high enough that the extensible continuous segment is plated in circumferential contact with the cylinder, which achieves almost complete sealing.
    Thus, according to the piston sealing device according to the patent application FR 3009037, a leak therefore remains transiently between the piston and the cylinder. This leak is in addition to that which occurs during the low-pressure phase found during the discharge stroke of a hydraulic motor or during the suction stroke of a hydraulic pump. Indeed, during said phase, the extensible continuous segment is parked and does not perform any other seal than that constituted by the restriction of fluid passage that forms the game left between said segment and the cylinder.
    This leak is necessary for the lubrication and cooling of the extensible continuous segment on the one hand, and the piston on the other hand.
    Depending on the type of pump or hydraulic motor to which the piston sealing device is addressed according to the patent application FR 3009037, the need for lubricating and cooling fluid may vary, in particular according to the importance of the effort radial force exerted by the piston on the cylinder.
    Indeed, the greater the effort, the greater the energy dissipated by friction and shearing oil at the interface between the piston and the cylinder, is important. To evacuate said energy, sufficient circulating oil is required.
    In addition, the need for lubricating oil tends to increase with said force because it is necessary in all circumstances to ensure a sufficient thickness of the oil film which separates the piston and the cylinder, so as to prevent any metal-metal contact between said piston and said cylinder.
    Furthermore, it will be noted that certain pumps or hydraulic motors comprise mechanical parts which are positioned opposite the fluid chamber receiving the fluid under pressure and which are lubricated and / or cooled by the leakage flow passing between the piston. and the cylinder. The tight seal of the piston sealing device according to the patent application FR 3009037 may, as the case may be, cause a problem of insufficient lubrication flow and / or cooling for both the piston itself and for any parts mechanical means with which said piston cooperates.
    One solution would be to place in various places of the pump housing or hydraulic motor one or more oil injectors to lubricate and / or cool the components that have just been listed. The problem is that such injectors inevitably complicate the hydraulic pump or the hydraulic motor that receives them. In addition, the lubrication of the piston in its cylinder may still be insufficient because the oil flow supplied by such injectors must reach parts of the cylinder made inaccessible by the piston.
    The cooling and lubrication system for a piston sealing device according to the invention is therefore mainly intended for hydraulic pumps and motors equipped with the piston sealing device according to the patent application FR 3009037, the flow rate of cooling fluid and lubrication has become insufficient because of the tightness achieved by said device. As such, depending on the type of application, the cooling and lubrication system for piston sealing device according to the invention allows, depending on its embodiment: • To generate a leakage flow of lubricating oil and significant cooling at the cost of a minimal reduction in volumetric efficiency and energy of the hydraulic pump or the hydraulic motor that receives it; • To avoid developing a injector (s) of lubrication and cooling in the housing of any pump or hydraulic motor that receives the piston sealing device according to the patent application FR 3009037; • Provide a flow of lubricating oil and cooling at the interface between the piston and the cylinder, in areas usually inaccessible to the jet of oil of an oil injector; • To increase only marginally the manufacturing cost of the pump piston or hydraulic motor that receives the piston sealing device according to the patent application FR 3009037.
    It is understood that besides its application to hydraulic pumps and hydraulic motors with axial or radial pistons, the cooling and lubrication system for a piston sealing device according to the invention can be applied to any other pump, motor, motor -pump or hydraulic or pneumatic cylinder whose configuration advantageously allows to operate said system.
    The other features of the present invention have been described in the description and in the dependent claims directly or indirectly dependent on the main claim.
    The cooling and lubricating system according to the present invention is provided for a piston sealing device, the latter being itself provided for a piston operating in a cylinder so as to constitute a fluid chamber, said piston comprising a piston head which comprises a fixed skirt and which has, on the one hand, a plunger bearing face for exerting a force on transmission means and, on the other hand, a compression face opening into the fluid chamber to receive the pressure of a fluid while a sliding skirt is housed in the cylinder with a small clearance, in the extension of the piston head on the side of the compression face and in the axis of said head, said sliding skirt being connected to said head by a mechanical inter-skirt connection while a pressure transmission channel is arranged inside the slippery skirt and passes through the latter through and through ns the axial direction, the piston sealing device also comprising an extensible continuous segment interposed between the fixed skirt and the sliding skirt, said segment comprising a segment internal cylindrical face subjected to the pressure of the fluid via the pressure transmission channel, a cylindrical outer face of a segment that can come into contact with the cylinder, a fixed skirt-side segment axial face held directly or indirectly in sealing contact with the fixed skirt and a sliding skirt-side segment axial face held directly or indirectly in sealing contact with the slippery skirt even as a sliding skirt spring tends to bring the sliding skirt closer to the fixed skirt and axially compress the extensible continuous segment, said system comprising: At least one skirt ring stopper which prevents the skirt slippery to move away from the piston beyond a certain distance; • At least one flow valve axially traversed and more or less sealed by the inter-skirt mechanical connection and interposed between the extensible continuous segment and the piston head, said valve comprising firstly, an axial face of the valve head side plunger which has a circular flow closure range, the latter defining with a valve contact surface arranged on the compression face a circular contact line whose diameter is significantly smaller than that of the cylinder, said valve comprising second part, an axial slider-side valve-facing side held directly or indirectly in sealing contact with the expandable continuous segment, said valve comprising thirdly, a flow calibration orifice which passes axially through said valve; At least one intermediate fluid outlet chamber whose volume is formed inside the circular contact line by the axial face of the valve on the piston head side, by the compression face and by the external surface of the piston. inter-skirt mechanical connection; • At least one valve return spring that tends to move the flow valve away from the piston head.
    The cooling and lubricating system according to the present invention comprises a valve return spring which acts as a sliding skirt spring.
    The cooling and lubricating system according to the present invention comprises a flow calibration orifice which consists of the clearance left between the flow valve and the inter-skirt mechanical connection.
    The cooling and lubricating system according to the present invention comprises a valve return spring which is housed inside the intermediate fluid outlet chamber.
    The cooling and lubrication system according to the present invention comprises a slidable skirt spring which is housed inside a spring cup arranged or attached in the sliding skirt.
    The cooling and lubricating system according to the present invention comprises a sliding skirt ring abutment which is traversed right through by at least one fluid passage opening.
    The cooling and lubricating system according to the present invention comprises an outer cylindrical face of the piston head which has a circular decompression groove which limits the tightness of said head.
    The following description with reference to the accompanying drawings and given by way of non-limiting example will better understand the invention, the features it has, and the benefits it is likely to provide:
    Figure 1 is a schematic sectional view of a variable displacement axial piston hydraulic pump whose pistons receive the cooling system and lubrication according to the invention.
    Figure 2 is a schematic sectional view of the cooling system and lubrication according to the invention.
    Figure 3 is a schematic sectional view of the cooling and lubrication system according to the invention, the valve return spring acts as sliding skirt spring.
    Figures 4 and 5 are schematic sectional views that illustrate the operation of the cooling system and lubrication according to the invention, the pressure in the fluid chamber being respectively low and high.
    Figure 6 is a three-dimensional view of an assembled piston which is equipped with the cooling and lubricating system according to the invention, and the piston sealing device which it perfects.
    Figure 7 is an exploded three-dimensional view of a piston which is equipped with the cooling and lubrication system according to the invention, and the piston sealing device that it perfects. DESCRIPTION OF THE INVENTION
    FIGS. 1 to 7 show the cooling and lubricating system 1 for the piston sealing device 2, various details of its components, its variants and its accessories.
    The cooling and lubricating system 1 is provided for a piston sealing device 2, the latter being itself provided for a piston 3 operating in a cylinder 4 so as to constitute a fluid chamber 5, said piston 3 comprising a head piston 6 which has a fixed skirt 7 and which has, on the one hand, a piston bearing face 8 for exerting a force on transmission means 9 and on the other hand, a compression face 10 opening into the chamber fluid 5 for receiving the pressure of a fluid 11.
    The piston sealing device 2 to which the cooling and lubricating system 1 according to the invention applies further comprises a sliding skirt 12 which is housed in the cylinder 4 with a small clearance, in the extension of the piston head. 6 on the side of the compression face 10 and in the axis of said head 6, said sliding skirt 12 being connected to said head 6 by an inter-skeletal mechanical connection 13 while a pressure transmission channel 14 is arranged at the inside of the sliding skirt 12 and crosses the latter from one side to the other in the axial direction.
    The piston sealing device 2 to which the cooling and lubricating system 1 according to the invention applies also comprises an extensible continuous segment 15 interposed between the fixed skirt 7 and the sliding skirt 12, said segment comprising a cylindrical internal face of segment 16 subjected to the pressure of the fluid 11 via the pressure transmission channel 14, an outer cylindrical surface of segment 17 that can come into contact with the cylinder 4, an axial face of fixed skirt segment segment 18 maintained directly or indirectly in leaktight contact with the fixed skirt 7 and an axial side segment sliding skirt segment 19 maintained directly or indirectly in sealing contact with the sliding skirt 12 even as a sliding skirt spring 20 tends to bring the sliding skirt 12 of the fixed skirt 7 and axially compressing the extensible continuous segment 15.
    As shown in FIGS. 1 to 5 and FIG. 7, the cooling and lubricating system 1 for a piston sealing device 2 according to the invention comprises at least one sliding skirt ring stop 21 which prevents the sliding skirt 12 to move away from the piston 3 beyond a certain distance;
    FIGS. 1 to 7 illustrate that the cooling and lubricating system 1 for a piston sealing device 2 according to the invention comprises at least one flow valve 22 traversed axially and more or less tightly sealed by the inter-skid mechanical connection 13 and interposed between the continuous expandable segment 15 and the piston head 6.
    Said valve 22 comprises, firstly, an axial piston-head-type valve face 23 which has a circular flow closure surface 24, the latter defining with a valve contact surface 26 arranged on the compression face 10 a nip circular 25 whose diameter is significantly smaller than that of the cylinder 4.
    Said valve 22 comprises, on the other hand, an axial sliding-side valve face 28 held directly or indirectly in sealing contact with the extensible continuous segment 15.
    Said valve 22 comprises thirdly, a flow calibration orifice 27 which passes through said valve 22 from one side to the other in the axial direction.
    Note that according to a particular embodiment of the cooling and lubricating system 1 according to the invention, the flow valve 22 can be held radially centered in the cylinder 4 by the interjupes mechanical connection 13 around which it is mounted at low clearance , while the outer cylindrical face of said valve 22 remains at a distance from the inner wall of the cylinder 4 without ever coming into contact with said wall.
    As is evident from FIGS. 1 to 5, the cooling and lubricating system 1 for a piston sealing device 2 according to the invention comprises at least one intermediate fluid outlet chamber 29 whose volume is formed the inside of the circular contact line 25 - by the axial face of the valve on the piston head side 23, by the compression face 10 and by the external surface of the inter-skirt mechanical connection 13.
    Finally, FIGS. 1 to 5 and FIG. 7 show that the cooling and lubricating system 1 for a piston sealing device 2 according to the invention comprises at least one valve return spring 30 which tends to move the flow valve away from the valve 22 of the piston head 6.
    FIG. 3 illustrates that the cooling and lubricating system 1 for a piston sealing device 2 according to the invention provides that the valve return spring 30 can act as a sliding skirt spring 20.
    In fact, the valve return spring 30 tends to bring the flow valve 22 closer to the sliding skirt 12 and to axially compress the extensible continuous segment 15 between said valve 22 and said skirt 12 as is provided by the device sealing ring for the piston according to the patent application FR 3009037.
    This substitution can be acceptable especially when the cooling and lubricating system 1 for piston sealing device 2 according to the invention applies to certain hydraulic pumps. As a variant, the flow calibration orifice 27 may consist of the clearance left between the flow valve 22 and the inter-skirt mechanical connection 13, said clearance being calculated to allow the desired flow of fluid 11 to flow from the chamber fluid 5 to the fluid outlet intermediate chamber 29.
    FIGS. 1 to 5 and FIG. 7 illustrate that the valve return spring 30 can be housed inside the intermediate fluid outlet chamber 29, said spring being able to be of helical, compression, traction or torsion, consisting of one or more "Belleville" washers stacked in series or in parallel, or of a type known to those skilled in the art.
    As shown in FIGS. 1, 2, 4, 5 and 7, the sliding skirt spring 20 can be housed inside a spring cup 31 fitted or attached in the sliding skirt 12, said spring 30 being able to be helical type, compression, traction or torsion, consisting of one or more "Belleville" washers stacked in series or in parallel, or of a type known to those skilled in the art.
    It is particularly visible in FIGS. 4 and 5 that according to the cooling and lubricating system 1 for a piston sealing device 2 according to the invention, the sliding skirt ring abutment 21 can be traversed right through by at least one fluid passage opening 32 which allows the fluid 11 contained in the fluid chamber 5 to pass freely through said abutment 21 to, on the one hand, exert pressure on the internal cylindrical segment face 16 and, on the other hand, cool and lubricate the piston 3 opening out of the intermediate fluid outlet chamber 29 after having entered the latter in particular via the flow calibration orifice 27.
    As can be seen in FIGS. 2 to 7, the outer cylindrical face of the piston head 6 may have a circular decompression groove 33 which limits the sealing of said head 6, which favors the operation of the continuous expandable segment 15, said circular groove 33 which - according to a particular embodiment of the articulated hitch 1 according to the invention - cooperate with at least one axial decompression groove 34 as shown in Figures 6 and 7 which connects said circular groove 33 with the face d piston support 8.
    It is noted that advantageously, the axial decompression groove 34 may be helical to distribute the bearing pressure exerted by the outer cylindrical face of the piston head 6 on the cylinder 4. OPERATION OF THE INVENTION:
    The operation of the cooling and lubricating system 1 for a piston sealing device 2 according to the invention is easily understood in the light of FIGS. 1 to 7.
    Figure 1 shows the cooling and lubrication system 1 applied to a variable displacement axial piston hydraulic pump 35 known per se. It will be noted that the pistons 3 of said pump 35 are naturally equipped with the piston seal 2 which is the subject of the patent application FR 3009037 which is perfected by the cooling and lubricating system 1 according to the invention.
    When a transmission shaft 36 that has said pump 35 is rotated by a drive source not shown, said shaft 36 in turn drives a barrel 37 in rotation, the latter being integral with said shaft 36.
    When a tilt plate 38 provided by said pump 35 tilts, concomitantly, the pistons 3 of said pump 35 start to go back and forth in the cylinder 4 with which they cooperate. As a result, said pistons 3 draw fluid 11 into an intake duct 39 which is fed with said fluid 11 under a low pressure of, for example, ten bars, and then expel said fluid 11 into a delivery duct 40 in which said fluid It is brought to a pressure of, for example, four hundred bars.
    In accordance with the patent application FR 3009037 relating to the piston sealing device 2, the extensible continuous segment 15 of each piston 3 passes successively from the parked state when the pressure prevailing in the fluid chamber 5 with which it cooperates is ten bars in the sealed contact state with the cylinder 4 when the pressure in said chamber 5 is four hundred bars. The tight seal that the extensible continuous segment 15 achieves with the cylinder 4 when the pressure in the fluid chamber 5 is four hundred bars allows only a very small amount of fluid 11 to flow between the said segment 15 and the said cylinder 4. when the pressure in the fluid chamber 5 is only 10 bar, although said segment 15 is parked, the small clearance left between the sliding skirt 12 and the cylinder 4 on the one hand, and between the continuous segment extensible 15 and the same said cylinder 4 on the other hand, leaves only very little fluid 11 to escape from the fluid chamber 5 via the clearance left between the piston 3 and the cylinder 4.
    However, the cooling and lubrication of the piston 3 may require more fluid 11 than the stretched continuous segment 15 and the sliding skirt 12 with which it cooperates. This is why - as is clearly illustrated in FIG. 4 - according to the cooling and lubrication system 1 according to the invention, it is possible for additional fluid 11 to pass directly from the fluid chamber 5 to the space that constitutes the clearance left between the piston 3 and the cylinder 4 without passing either by the clearance left between the sliding skirt 12 and the cylinder 4, nor by the gap left between the extensible continuous segment 15 and the same said cylinder 4.
    According to the cooling and lubricating system 1 according to the invention, said additional fluid 11 can in fact pass successively via the fluid passage orifice 32 arranged in the sliding skirt ring stop 21, the pressure transmission channel 14, the flow calibration orifice 27, the intermediate fluid outlet chamber 29 and the clearance left between the circular flow closure area 24 and the valve contact surface 26. It should be noted that this last set exists only when the pressure in the fluid chamber 5 is low, or in the vicinity of only ten bars according to the example retained here.
    In fact, as illustrated in FIG. 4, when the pressure prevailing in the fluid chamber 5 is low, the force exerted by the pressure of the fluid 11 on the axial face of the slide-skirt-side valve 28 is less than the force exerted by the valve return spring 30 on the axial face of the valve on the piston head side 23.
    As a result, the flow valve 22 remains remote from the piston 3 and the clearance left between the piston 3 and the cylinder 4 is supplied with fluid 11 intended to cool and lubricate the piston 3. It is noted that the diameter and the length of the Flow calibration orifice 27 are provided to produce the pressure drop required to obtain the desired fluid flow at low pressure.
    It will also be noted that the force exerted by the pressure of the fluid 11 on the axial face of the sliding skirt valve 28 corresponds approximately to the product of the pressure of said fluid 11 by the area of the section of the cylinder 4 minus that defined by inside the circular closing range 24.
    Thus, the pressure prevailing in the fluid chamber 5 above which the flow valve 22 is closed - i.e. above which the circular flow closure surface 24 is in contact with the contact surface valve 26 - depends on the relationship between the tare and the stiffness of the valve return spring 30 on the one hand, and the area defined by the inside of the circular flow closing range 24 on the other hand.
    It is understood that at low pressure, the continuous extensible segment 15 is kept strongly compressed between the flow valve 22 and the sliding skirt 12 because the force produced by the valve return spring 30 is significantly greater than that produced by the spring. As soon as the pressure in the fluid chamber 5 exceeds the threshold of displacement of the flow valve 22 - as illustrated in FIG. 5, the sliding skirt 12 takes off from the stop of the sliding skirt ring 21. and the extensible continuous segment 15 is no longer held compressed by the sliding skirt spring 20. Said segment 15 can then operate in conditions identical to those provided by the piston sealing device 2 as described in the application of patent FR 3009037.
    If the cooling and lubricating system 1 according to the invention is provided so that the force exerted by the pressure of the fluid 11 on the axial face of the sliding skirt valve 28 becomes greater than the force exerted by the return spring. valve 30 on the axial face of the piston head valve 23 from a pressure of fifteen bars in the fluid chamber 5 and that, taking into account the stiffness of the valve return spring 30, the flow valve 22 is completely closed at twenty-five bars, then, fluid 11 for cooling and lubricating the piston 3 will pass through the flow calibration orifice 27 as soon as the pressure in the fluid chamber 5 is between a few millibars and twenty-five bars.
    Also, the ratio between the flow rate of fluid 11 for cooling and lubrication on the one hand, and the pressure in the fluid chamber 5 on the other hand, is well fixed by the pressure drop constituted by the calibration orifice. flow rate 27 to which is added the sum of the pressure losses encountered on its path between the fluid chamber 5 and the outlet of the cylinder 4 opposite said chamber 5, by the flow 11 fluid. It is noted that the total energy lost due to said flow of fluid 11 remains in all cases low because the pressure at which said flow rate remains low.
    Thus, the cooling and lubrication system 1 for a piston sealing device 2 according to the invention makes it possible to provide the piston 3 with significant additional cooling and lubrication at a lower energy cost, without jeopardizing the almost complete seal. -perfect and the low friction losses of the piston sealing device 2 as provided in the patent application FR 3009037.
    The cooling and lubrication system possibilities 1 for piston sealing device 2 according to the invention according to the invention are not limited to the applications which have just been described and it must also be understood that the description which precedes has been given as an example and it does not limit the scope of said invention which would not be out by replacing the execution details described by any other equivalent.
    COOLING AND LUBRICATION SYSTEM FOR PISTON SEALING DEVICE
    The present invention relates to a cooling and lubrication system for a piston sealing device. Said invention is an improvement of the piston sealing device subject of the patent application FR 3009037 dated July 23, 2013 belonging to the applicant. Said device is particularly suitable for any piston operating under high pressure.
    The piston sealing device according to the patent application FR 3009037 is provided for a piston operating in a cylinder whose one end is closed by a fluid chamber, said piston comprising at least one piston head which comprises at least a fixed skirt, said head having on the one hand a plunger bearing face for exerting a force on any mechanical, hydraulic or pneumatic transmission means and, on the other hand, a compression face opening into the fluid chamber and able to receive the pressure of a fluid.
    Still according to the patent application FR 3009037, the piston sealing device comprises a sliding skirt of cylindrical shape housed in a cylinder with a small clearance. Said skirt is further placed in the extension of the piston head on the side of the piston. compression side and in the axis of said head.
    It is noted that said sliding skirt is connected to said head by an inter-skirt mechanical connection which allows it to move in longitudinal translation relative to said head while a pressure transmission channel arranged inside the sliding skirt crosses the latter from side to side in the axial direction. The invention of the patent application FR 3009037 is also characterized by an extensible continuous ring-shaped continuous segment which is interposed between the fixed skirt and the sliding skirt. Said segment comprises an internal cylindrical segment face subjected to the pressure of the fluid via the pressure transmission channel, an outer cylindrical segment face that can come into contact with the cylinder, a fixed skirt-side segment axial face maintained directly or indirectly by sealing contact with the fixed skirt and an axial side segment sliding skirt side directly or indirectly in sealing contact with the sliding skirt.
    Finally, the invention relating to the patent application FR 3009037 is also characterized by a sliding skirt spring which tends to bring the sliding skirt closer to the fixed skirt and compress axially the continuous segment extensible or at least, which prohibits said slippery skirt to move away from the fixed skirt like a stop. When reading patent FR 3009037, it is understood that the maximum leakage rate of fluid flowing between the piston and the cylinder is found when the pressure in the fluid chamber is sufficiently high to maximize the flow of fluid passing through. in the game left between the sliding skirt and the cylinder, but not yet high enough that the extensible continuous segment is plated in circumferential contact with the cylinder, which achieves almost complete sealing.
    Thus, according to the piston sealing device according to the patent application FR 3009037, a leak therefore remains transiently between the piston and the cylinder. This leak is in addition to that which occurs during the low-pressure phase found during the discharge stroke of a hydraulic motor or during the suction stroke of a hydraulic pump. Indeed, during said phase, the extensible continuous segment is parked and does not perform any other seal than that constituted by the restriction of fluid passage that forms the game left between said segment and the cylinder.
    This leak is necessary for the lubrication and cooling of the extensible continuous segment on the one hand, and the piston on the other hand.
    Depending on the type of pump or hydraulic motor to which the piston sealing device is addressed according to the patent application FR 3009037, the need for lubricating and cooling fluid may vary, in particular according to the importance of the effort radial force exerted by the piston on the cylinder.
    Indeed, the greater the effort, the greater the energy dissipated by friction and shearing oil at the interface between the piston and the cylinder, is important. To evacuate said energy, sufficient circulating oil is required.
    In addition, the need for lubricating oil tends to increase with said force because it is necessary in all circumstances to ensure a sufficient thickness of the oil film which separates the piston and the cylinder, so as to prevent any metal-metal contact between said piston and said cylinder.
    Furthermore, it will be noted that certain pumps or hydraulic motors comprise mechanical parts which are positioned opposite the fluid chamber receiving the fluid under pressure and which are lubricated and / or cooled by the leakage flow passing between the piston. and the cylinder. The tight seal of the piston sealing device according to the patent application FR 3009037 may, as the case may be, cause a problem of insufficient lubrication flow and / or cooling for both the piston itself and for any parts mechanical means with which said piston cooperates.
    One solution would be to place in various places of the pump housing or hydraulic motor one or more oil injectors to lubricate and / or cool the components that have just been listed. The problem is that such injectors inevitably complicate the hydraulic pump or the hydraulic motor that receives them. In addition, the lubrication of the piston in its cylinder may still be insufficient because the oil flow supplied by such injectors must reach parts of the cylinder made inaccessible by the piston.
    The cooling and lubrication system for a piston sealing device according to the invention is therefore mainly intended for hydraulic pumps and motors equipped with the piston sealing device according to the patent application FR 3009037, the flow rate of cooling fluid and lubrication has become insufficient because of the tightness achieved by said device. As such, depending on the type of application, the cooling and lubrication system for piston sealing device according to the invention allows, depending on its embodiment: • To generate a leakage flow of lubricating oil and significant cooling at the cost of a minimal reduction in volumetric efficiency and energy of the hydraulic pump or the hydraulic motor that receives it; • To avoid developing a injector (s) of lubrication and cooling in the housing of any pump or hydraulic motor that receives the piston sealing device according to the patent application FR 3009037; • Provide a flow of lubricating oil and cooling at the interface between the piston and the cylinder, in areas usually inaccessible to the jet of oil of an oil injector; • To increase only marginally the manufacturing cost of the pump piston or hydraulic motor that receives the piston sealing device according to the patent application FR 3009037.
    It is understood that besides its application to hydraulic pumps and hydraulic motors with axial or radial pistons, the cooling and lubrication system for a piston sealing device according to the invention can be applied to any other pump, motor, motor -pump or hydraulic or pneumatic cylinder whose configuration advantageously allows to operate said system.
    The other features of the present invention have been described in the description and in the dependent claims directly or indirectly dependent on the main claim.
    The cooling and lubricating system according to the present invention is provided for a piston sealing device, the latter being itself provided for a piston operating in a cylinder so as to constitute a fluid chamber, said piston comprising a piston head which comprises a fixed skirt and which has, on the one hand, a plunger bearing face for exerting a force on transmission means and, on the other hand, a compression face opening into the fluid chamber to receive the pressure of a fluid while a sliding skirt is housed in the cylinder with a small clearance, in the extension of the piston head on the side of the compression face and in the axis of said head, said sliding skirt being connected to said head by a mechanical inter-skirt connection while a pressure transmission channel is arranged inside the slippery skirt and passes through the latter through and through ns the axial direction, the piston sealing device also comprising an extensible continuous segment interposed between the fixed skirt and the sliding skirt, said segment comprising a segment internal cylindrical face subjected to the pressure of the fluid via the pressure transmission channel, a cylindrical outer face of a segment that can come into contact with the cylinder, a fixed skirt-side segment axial face held directly or indirectly in sealing contact with the fixed skirt and a sliding skirt-side segment axial face held directly or indirectly in sealing contact with the slippery skirt even as a sliding skirt spring tends to bring the sliding skirt closer to the fixed skirt and axially compress the extensible continuous segment, said system comprising: At least one skirt ring stopper which prevents the skirt slippery to move away from the piston beyond a certain distance; • At least one flow valve axially traversed and more or less sealed by the inter-skirt mechanical connection and interposed between the extensible continuous segment and the piston head, said valve comprising firstly, an axial face of the valve head side plunger which has a circular flow closure range, the latter defining with a valve contact surface arranged on the compression face a circular contact line whose diameter is significantly smaller than that of the cylinder, said valve comprising second part, an axial slider-side valve-facing side held directly or indirectly in sealing contact with the expandable continuous segment, said valve comprising thirdly, a flow calibration orifice which passes axially through said valve; At least one intermediate fluid outlet chamber whose volume is formed inside the circular contact line by the axial face of the valve on the piston head side, by the compression face and by the external surface of the piston. inter-skirt mechanical connection; • At least one valve return spring that tends to move the flow valve away from the piston head.
    The cooling and lubricating system according to the present invention comprises a valve return spring which acts as a sliding skirt spring.
    The cooling and lubricating system according to the present invention comprises a flow calibration orifice which consists of the clearance left between the flow valve and the inter-skirt mechanical connection.
    The cooling and lubricating system according to the present invention comprises a valve return spring which is housed inside the intermediate fluid outlet chamber.
    The cooling and lubrication system according to the present invention comprises a slidable skirt spring which is housed inside a spring cup arranged or attached in the sliding skirt.
    The cooling and lubricating system according to the present invention comprises a sliding skirt ring abutment which is traversed right through by at least one fluid passage opening.
    The cooling and lubricating system according to the present invention comprises an outer cylindrical face of the piston head which has a circular decompression groove which limits the tightness of said head.
    The following description with reference to the accompanying drawings and given by way of non-limiting example will better understand the invention, the features it has, and the benefits it is likely to provide:
    Figure 1 is a schematic sectional view of a variable displacement axial piston hydraulic pump whose pistons receive the cooling system and lubrication according to the invention.
    Figure 2 is a schematic sectional view of the cooling system and lubrication according to the invention.
    Figure 3 is a schematic sectional view of the cooling and lubrication system according to the invention, the valve return spring acts as sliding skirt spring.
    Figures 4 and 5 are schematic sectional views that illustrate the operation of the cooling system and lubrication according to the invention, the pressure in the fluid chamber being respectively low and high.
    Figure 6 is a three-dimensional view of an assembled piston which is equipped with the cooling and lubricating system according to the invention, and the piston sealing device that it perfected.
    Figure 7 is an exploded three-dimensional view of a piston which is equipped with the cooling and lubrication system according to the invention, and the piston sealing device that it perfects. DESCRIPTION OF THE INVENTION
    FIGS. 1 to 7 show the cooling and lubricating system 1 for the piston sealing device 2, various details of its components, its variants and its accessories.
    The cooling and lubricating system 1 is provided for a piston sealing device 2, the latter being itself provided for a piston 3 operating in a cylinder 4 so as to constitute a fluid chamber 5, said piston 3 comprising a head piston 6 which has a fixed skirt 7 and which has, on the one hand, a piston bearing face 8 for exerting a force on transmission means 9 and on the other hand, a compression face 10 opening into the chamber fluid 5 for receiving the pressure of a fluid 11.
    The piston sealing device 2 to which the cooling and lubricating system 1 according to the invention applies further comprises a sliding skirt 12 which is housed in the cylinder 4 with a small clearance, in the extension of the piston head. 6 on the side of the compression face 10 and in the axis of said head 6, said sliding skirt 12 being connected to said head 6 by an inter-skeletal mechanical connection 13 while a pressure transmission channel 14 is arranged at the inside of the sliding skirt 12 and crosses the latter from one side to the other in the axial direction.
    The piston sealing device 2 to which the cooling and lubricating system 1 according to the invention applies also comprises an extensible continuous segment 15 interposed between the fixed skirt 7 and the sliding skirt 12, said segment comprising a cylindrical internal face of segment 16 subjected to the pressure of the fluid 11 via the pressure transmission channel 14, an outer cylindrical surface of segment 17 that can come into contact with the cylinder 4, an axial face of fixed skirt segment segment 18 maintained directly or indirectly in leaktight contact with the fixed skirt 7 and an axial side segment sliding skirt segment 19 maintained directly or indirectly in sealing contact with the sliding skirt 12 even as a sliding skirt spring 20 tends to bring the sliding skirt 12 of the fixed skirt 7 and axially compressing the extensible continuous segment 15.
    As shown in FIGS. 1 to 5 and FIG. 7, the cooling and lubricating system 1 for a piston sealing device 2 according to the invention comprises at least one sliding skirt ring stop 21 which prevents the sliding skirt 12 to move away from the piston 3 beyond a certain distance;
    FIGS. 1 to 7 illustrate that the cooling and lubricating system 1 for a piston sealing device 2 according to the invention comprises at least one flow valve 22 traversed axially and more or less tightly sealed by the inter-skid mechanical connection 13 and interposed between the continuous expandable segment 15 and the piston head 6.
    Said valve 22 comprises, firstly, an axial piston-head-type valve face 23 which has a circular flow closure surface 24, the latter defining with a valve contact surface 26 arranged on the compression face 10 a nip circular 25 whose diameter is significantly smaller than that of the cylinder 4.
    Said valve 22 comprises, on the other hand, an axial sliding-side valve face 28 held directly or indirectly in sealing contact with the extensible continuous segment 15.
    Said valve 22 comprises thirdly, a flow calibration orifice 27 which passes through said valve 22 from one side to the other in the axial direction.
    Note that according to a particular embodiment of the cooling and lubricating system 1 according to the invention, the flow valve 22 can be held radially centered in the cylinder 4 by the interjupes mechanical connection 13 around which it is mounted at low clearance , while the outer cylindrical face of said valve 22 remains at a distance from the inner wall of the cylinder 4 without ever coming into contact with said wall.
    As is evident from FIGS. 1 to 5, the cooling and lubricating system 1 for a piston sealing device 2 according to the invention comprises at least one intermediate fluid outlet chamber 29 whose volume is formed the inside of the circular contact line 25 - by the axial face of the valve on the piston head side 23, by the compression face 10 and by the external surface of the inter-skirt mechanical connection 13.
    Finally, FIGS. 1 to 5 and FIG. 7 show that the cooling and lubricating system 1 for a piston sealing device 2 according to the invention comprises at least one valve return spring 30 which tends to move the flow valve away from the valve 22 of the piston head 6.
    FIG. 3 illustrates that the cooling and lubricating system 1 for a piston sealing device 2 according to the invention provides that the valve return spring 30 can act as a sliding skirt spring 20.
    In fact, the valve return spring 30 tends to bring the flow valve 22 closer to the sliding skirt 12 and to axially compress the extensible continuous segment 15 between said valve 22 and said skirt 12 as is provided by the device sealing ring for the piston according to the patent application FR 3009037.
    This substitution can be acceptable especially when the cooling and lubricating system 1 for piston sealing device 2 according to the invention applies to certain hydraulic pumps. As a variant, the flow calibration orifice 27 may consist of the clearance left between the flow valve 22 and the inter-skirt mechanical connection 13, said clearance being calculated to allow the desired flow of fluid 11 to flow from the chamber fluid 5 to the fluid outlet intermediate chamber 29.
    FIGS. 1 to 5 and FIG. 7 illustrate that the valve return spring 30 can be housed inside the intermediate fluid outlet chamber 29, said spring being able to be of helical, compression, traction or torsion, consisting of one or more "Belleville" washers stacked in series or in parallel, or of a type known to those skilled in the art.
    As shown in FIGS. 1, 2, 4, 5 and 7, the sliding skirt spring 20 can be housed inside a spring cup 31 fitted or attached in the sliding skirt 12, said spring 30 being able to be helical type, compression, traction or torsion, consisting of one or more "Belleville" washers stacked in series or in parallel, or of a type known to those skilled in the art.
    It is particularly visible in FIGS. 4 and 5 that according to the cooling and lubricating system 1 for a piston sealing device 2 according to the invention, the sliding skirt ring abutment 21 can be traversed right through by at least one fluid passage opening 32 which allows the fluid 11 contained in the fluid chamber 5 to pass freely through said abutment 21 to, on the one hand, exert pressure on the internal cylindrical segment face 16 and, on the other hand, cool and lubricate the piston 3 opening out of the intermediate fluid outlet chamber 29 after having entered the latter in particular via the flow calibration orifice 27.
    As can be seen in FIGS. 2 to 7, the outer cylindrical face of the piston head 6 may have a circular decompression groove 33 which limits the sealing of said head 6, which favors the operation of the continuous expandable segment 15, said circular groove 33 which - according to a particular embodiment of the articulated hitch 1 according to the invention - cooperate with at least one axial decompression groove 34 as shown in Figures 6 and 7 which connects said circular groove 33 with the face d piston support 8.
    It is noted that advantageously, the axial decompression groove 34 may be helical to distribute the bearing pressure exerted by the outer cylindrical face of the piston head 6 on the cylinder 4. OPERATION OF THE INVENTION:
    The operation of the cooling and lubricating system 1 for a piston sealing device 2 according to the invention is easily understood in the light of FIGS. 1 to 7.
    Figure 1 shows the cooling and lubrication system 1 applied to a variable displacement axial piston hydraulic pump 35 known per se. It will be noted that the pistons 3 of said pump 35 are naturally equipped with the piston seal 2 which is the subject of the patent application FR 3009037 which is perfected by the cooling and lubricating system 1 according to the invention.
    When a transmission shaft 36 that has said pump 35 is rotated by a drive source not shown, said shaft 36 in turn drives a barrel 37 in rotation, the latter being integral with said shaft 36.
    When a tilt plate 38 provided by said pump 35 tilts, concomitantly, the pistons 3 of said pump 35 start to go back and forth in the cylinder 4 with which they cooperate. As a result, said pistons 3 draw fluid 11 into an intake duct 39 which is fed with said fluid 11 under a low pressure of, for example, ten bars, and then expel said fluid 11 into a delivery duct 40 in which said fluid It is brought to a pressure of, for example, four hundred bars.
    In accordance with the patent application FR 3009037 relating to the piston sealing device 2, the extensible continuous segment 15 of each piston 3 passes successively from the parked state when the pressure prevailing in the fluid chamber 5 with which it cooperates is ten bars in the sealed contact state with the cylinder 4 when the pressure in said chamber 5 is four hundred bars. The tight seal that the extensible continuous segment 15 achieves with the cylinder 4 when the pressure in the fluid chamber 5 is four hundred bars allows only a very small amount of fluid 11 to flow between the said segment 15 and the said cylinder 4. when the pressure in the fluid chamber 5 is only 10 bar, although said segment 15 is parked, the small clearance left between the sliding skirt 12 and the cylinder 4 on the one hand, and between the continuous segment extensible 15 and the same said cylinder 4 on the other hand, leaves only very little fluid 11 to escape from the fluid chamber 5 via the clearance left between the piston 3 and the cylinder 4.
    However, the cooling and lubrication of the piston 3 may require more fluid 11 than the stretched continuous segment 15 and the sliding skirt 12 with which it cooperates. This is why - as is clearly illustrated in FIG. 4 - according to the cooling and lubrication system 1 according to the invention, it is possible for additional fluid 11 to pass directly from the fluid chamber 5 to the space that constitutes the clearance left between the piston 3 and the cylinder 4 without passing either by the clearance left between the sliding skirt 12 and the cylinder 4, nor by the gap left between the extensible continuous segment 15 and the same said cylinder 4.
    According to the cooling and lubricating system 1 according to the invention, said additional fluid 11 can in fact pass successively via the fluid passage orifice 32 arranged in the sliding skirt ring stop 21, the pressure transmission channel 14, the flow calibration orifice 27, the intermediate fluid outlet chamber 29 and the clearance left between the circular flow closure area 24 and the valve contact surface 26. It should be noted that this last set exists only when the pressure prevailing in the fluid chamber 5 is low, or in the vicinity of only ten bars according to the example retained here.
    In fact, as illustrated in FIG. 4, when the pressure prevailing in the fluid chamber 5 is low, the force exerted by the pressure of the fluid 11 on the axial face of the slide-skirt-side valve 28 is less than the force exerted by the valve return spring 30 on the axial face of the valve on the piston head side 23.
    As a result, the flow valve 22 remains remote from the piston 3 and the clearance left between the piston 3 and the cylinder 4 is supplied with fluid 11 intended to cool and lubricate the piston 3. It is noted that the diameter and the length of the Flow calibration orifice 27 are provided to produce the pressure drop required to obtain the desired fluid flow at low pressure.
    It will also be noted that the force exerted by the pressure of the fluid 11 on the axial face of the sliding skirt valve 28 corresponds approximately to the product of the pressure of said fluid 11 by the area of the section of the cylinder 4 minus that defined by inside the circular closing range 24.
    Thus, the pressure prevailing in the fluid chamber 5 above which the flow valve 22 is closed - i.e. above which the circular flow closure surface 24 is in contact with the contact surface valve 26 - depends on the relationship between the tare and the stiffness of the valve return spring 30 on the one hand, and the area defined by the inside of the circular flow closing range 24 on the other hand.
    It is understood that at low pressure, the continuous extensible segment 15 is kept strongly compressed between the flow valve 22 and the sliding skirt 12 because the force produced by the valve return spring 30 is significantly greater than that produced by the spring. As soon as the pressure in the fluid chamber 5 exceeds the threshold of displacement of the flow valve 22 - as illustrated in FIG. 5, the sliding skirt 12 takes off from the stop of the sliding skirt ring 21. and the extensible continuous segment 15 is no longer held compressed by the sliding skirt spring 20. Said segment 15 can then operate in conditions identical to those provided by the piston sealing device 2 as described in the application of patent FR 3009037.
    If the cooling and lubricating system 1 according to the invention is provided so that the force exerted by the pressure of the fluid 11 on the axial face of the sliding skirt valve 28 becomes greater than the force exerted by the return spring. valve 30 on the axial face of the piston head valve 23 from a pressure of fifteen bars in the fluid chamber 5 and that, taking into account the stiffness of the valve return spring 30, the flow valve 22 is completely closed at twenty-five bars, then, fluid 11 for cooling and lubricating the piston 3 will pass through the flow calibration orifice 27 as soon as the pressure in the fluid chamber 5 is between a few millibars and twenty-five bars.
    Also, the ratio between the flow rate of fluid 11 for cooling and lubrication on the one hand, and the pressure in the fluid chamber 5 on the other hand, is well fixed by the pressure drop constituted by the calibration orifice. flow rate 27 to which is added the sum of the pressure losses encountered on its path between the fluid chamber 5 and the outlet of the cylinder 4 opposite said chamber 5, by the flow 11 fluid. It is noted that the total energy lost due to said flow of fluid 11 remains in all cases low because the pressure at which said flow rate remains low.
    Thus, the cooling and lubrication system 1 for a piston sealing device 2 according to the invention makes it possible to provide the piston 3 with significant additional cooling and lubrication at a lower energy cost, without jeopardizing the almost complete seal. -perfect and the low friction losses of the piston sealing device 2 as provided in the patent application FR 3009037.
    The cooling and lubrication system possibilities 1 for piston sealing device 2 according to the invention according to the invention are not limited to the applications which have just been described and it must also be understood that the description which precedes has been given as an example and it does not limit the scope of said invention which would not be out by replacing the execution details described by any other equivalent.
    权利要求:
    Claims (7)
    [1" id="c-fr-0001]
    1. Cooling and lubrication system (1) for a piston sealing device (2), the latter being provided for a piston (3) operating in a cylinder (4) so as to constitute a fluid chamber (5), said piston (3) comprising a piston head (6) which has a fixed skirt (7) and which, on the one hand, has a piston bearing face (8) for exerting a force on transmission means (9) and on the other hand, a compression face (10) opening into the fluid chamber (5) to receive the pressure of a fluid (11) while a sliding skirt (12) is accommodated in the cylinder (4) with a slight clearance, in the extension of the piston head (6) on the side of the compression face (10) and in the axis of said head (6), said sliding skirt (12) being connected to said head ( 6) by an inter-skirt mechanical connection (13) while a pressure transmission channel (14) is arranged inside the sliding skirt (12) e t passes therethrough axially in the axial direction, the piston sealing device (2) also comprising an extensible continuous segment (15) interposed between the fixed skirt (7) and the sliding skirt (12), said segment ( 15) comprising a cylindrical inner segment face (16) subjected to fluid pressure (11) via the pressure transmission channel (14), an outer cylindrical segment face (17) engageable with the cylinder (4). ), a fixed skirt-side segment axial face (18) held directly or indirectly in sealing contact with the fixed skirt (7) and a sliding skirt-side segment axial face (19) maintained directly or indirectly in sealing contact with the sliding skirt (12) even though a sliding skirt spring (20) tends to bring the sliding skirt (12) closer to the fixed skirt (7) and axially compress the continuous expandable segment (15), said system (1) being characterized in that it includes: • To me ns a sliding skirt ring stop (21) which prevents the sliding skirt (12) from moving away from the piston (3) beyond a certain distance; • At least one flow valve (22) traversed axially and more or less tightly by the inter-skirt mechanical connection (13) and interposed between the extensible continuous segment (15) and the piston head (6), said valve (22) comprising, firstly, an axial piston head-side valve face (23) which has a circular flow closure surface (24), the latter defining with a valve contact surface (26) provided on the compression (10) a circular contact line (25) whose diameter is significantly smaller than that of the cylinder (4), said valve (22) comprising secondly, an axial axial valve side sliding skirt (28) held directly or indirectly in sealing contact with the expandable continuous segment (15), said valve (22) comprising thirdly, a flow calibration orifice (27) which passes axially through said valve (22); • At least one intermediate fluid outlet chamber (29) whose volume is formed - within the circular contact line (25) - by the axial face of the piston head-side valve (23), by the face compression member (10) and the outer surface of the inter-skirt mechanical link (13); • At least one valve return spring (30) which tends to move the flow valve (22) away from the piston head (6).
    [2" id="c-fr-0002]
    Cooling and lubrication system according to Claim 1, characterized in that the valve return spring (30) functions as a sliding skirt spring (20).
    [3" id="c-fr-0003]
    Cooling and lubrication system according to Claim 1, characterized in that the flow calibration orifice (27) consists of the clearance left between the flow valve (22) and the inter-skirt mechanical connection (13).
    [4" id="c-fr-0004]
    Cooling and lubrication system according to claim 1, characterized in that the valve return spring (30) is housed inside the intermediate fluid outlet chamber (29).
    [5" id="c-fr-0005]
    5. Cooling and lubrication system according to claim 1, characterized in that the slidable skirt spring (20) is housed inside a spring cup (31) arranged or reported in the sliding skirt (12).
    [6" id="c-fr-0006]
    Cooling and lubrication system according to Claim 1, characterized in that the sliding skirt ring stop (21) is traversed right through by at least one fluid passage opening (32).
    [7" id="c-fr-0007]
    Cooling and lubrication system according to claim 1, characterized in that the outer cylindrical face of the piston head (6) has a circular decompression groove (33) which limits the sealing of said head (6).
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    同族专利:
    公开号 | 公开日
    WO2017109329A1|2017-06-29|
    FR3046205B1|2018-02-16|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    FR2351263A1|1976-05-14|1977-12-09|Dana Corp|Articulated piston with head with gudgeon pin bearing - has mantle carried on bearing surface outside pin bearing element|
    WO2004074716A1|1994-05-02|2004-09-02|Michel Chatelain|Stepped piston for an engine, pump or compressor|
    US7730866B2|2005-12-05|2010-06-08|Jean Frederic Melchior|Sealing device|
    FR3009037A1|2013-07-23|2015-01-30|Vianney Rabhi|SEALING DEVICE FOR PISTON|CN110360095A|2019-08-20|2019-10-22|四川航天烽火伺服控制技术有限公司|Plunger assembly and plunger pump with the component|
    FR3070731B1|2017-09-05|2019-09-06|Vianney Rabhi|HYDRAULIC PISTON WITH COOLING VALVE AND LUBRICATION|
    FR3108690B1|2020-03-30|2022-03-04|Vianney Rabhi|depressurized throat hydraulic piston|
    法律状态:
    2016-12-20| PLFP| Fee payment|Year of fee payment: 2 |
    2017-06-30| PLSC| Publication of the preliminary search report|Effective date: 20170630 |
    2017-12-22| PLFP| Fee payment|Year of fee payment: 3 |
    2019-12-26| PLFP| Fee payment|Year of fee payment: 5 |
    2020-12-27| PLFP| Fee payment|Year of fee payment: 6 |
    2021-12-27| PLFP| Fee payment|Year of fee payment: 7 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1563316|2015-12-24|
    FR1563316A|FR3046205B1|2015-12-24|2015-12-24|COOLING AND LUBRICATION SYSTEM FOR PISTON SEALING DEVICE|FR1563316A| FR3046205B1|2015-12-24|2015-12-24|COOLING AND LUBRICATION SYSTEM FOR PISTON SEALING DEVICE|
    PCT/FR2016/053342| WO2017109329A1|2015-12-24|2016-12-12|Cooling and lubrication system for a piston sealing device|
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