• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    ROTOR FOR AN IPM ENGINE, AND, IPM ENGINE A rotor iron core is described which is formed by rolling a base steel plate with a magnetic flux density (B8000) of 1.65 T or more, measured at a magnetic field strength of 8,000 A / m and also with coercivity of 100 A / m or more.
    公开号:BR112013023948B1
    申请号:R112013023948-4
    申请日:2012-03-27
    公开日:2021-02-23
    发明作者:Tomonaga Iwatsu；Yukio Katagiri；Susumu Fujiwara；Shigeru Morikawa
    申请人:Nisshin Steel Co., Ltd；
    IPC主号:
    专利说明:

    TECHNICAL FIELD
    [001] The present invention relates to a rotor for an indoor permanent magnet motor (hereinafter “IPM motor”) which is used for electric vehicles, hybrid vehicles and machine tools, for example, and an IPM motor equipped with the rotor. BACKGROUND OF THE INVENTION
    [002] In general, IMP motors, which use expensive permanent magnets, are expensive, but more efficient than induction motors. Therefore, IPM motors are widely used for drive motors and power generation motors for hybrid vehicles and electric vehicles, and motors for household electrical appliances, various machine tools and industrial machines.
    [003] An iron core of IPM engines consists of a stator and a rotor. Since an AC magnetic field is directly applied to the iron core on the stator side by means of windings, the iron core on the stator side must have high magnetic permeability and high volumetric resistivity in order to reduce iron loss. Consequently, electromagnetic steel sheets, of which the soft magnetic characteristics have been improved by adding Si to ultra low carbon steel, are used for the iron core on the stator side.
    [004] The iron core on the stator side, on the other hand, basically plays a role in increasing the magnetic flux density as a breech, since the permanent magnet is embedded in the iron core on the rotor side. The iron core on the rotor side is less affected by the AC magnetic field generated by the stator side, but this influence is limited. Therefore, in terms of characteristics, it is not necessary to use electromagnetic steel sheets, which are advantageous for iron loss characteristics, for the iron core on the rotor side. However, the same electromagnetic steel sheets as the stator side are also used for the iron core on the rotor side, as the product yield of electromagnetic steel sheets drops and the engine manufacturing costs increase, if the electromagnetic steel sheets are used only for the stator.
    [005] In the case of mounting an IPM engine in a vehicle, a miniaturization of the IPM engine is expected because the vehicle has to be compact and light. In this case, the rotational speed of the rotor is increased in order to obtain a motor output (torque) equivalent to or greater than that of a conventional motor, despite miniaturization. In general, the efficiency of an engine improves as the rotational speed of the rotor increases. However, in the case of an IPM motor, an induced electromotive shape is generated in the stator windings by the rotation of the built-in permanent magnet. The induced electromotive force increases as the rotational speed increases. Then, the motor can no longer rotate when the electromotive force exceeds the input voltage.
    [006] Therefore, in an IPM motor, a field weakening control, which suppresses the induced electromotive force by generating a magnetic flux on the stator side in one direction to cancel the permanent magnet's magnetic flux, is performed when the motor is operated in a high rotational speed range, as described in patent document 1, for example. Although operation in a high rotational speed range is possible, field weakening control decreases the motor torque because power is used to cancel the magnetic flux from the permanent magnet. According to patent document 1, electrical energy to be used for the control of field weakening can be decreased by improving the shape of the magnet.
    [007] On the other hand, even if the IPM motor is miniaturized, there is a problem where the centrifugal force acting on the permanent magnet embedded in the rotor increases to the point of damaging the rotor, if the rotational speed of the rotor is increased in order to obtain a torque equivalent to or greater than that of conventional rotors. To prevent damage, it is preferable to use a material with a high flow limit for the rotor material. For example, in the case of non-oriented electromagnetic steel sheets (35A300) containing about 3% Si, the yield limit after magnetic annealing is approximately 400 N / mm2. Therefore, in the case of a relatively large IPM engine, where the rotor diameter is 80 mm or more, the limit of the rotational speed at which damage is not caused is around 20,000 rpm, although the value is slightly different depending on the structure of the rotor. Several studies have been done to increase the flow limit of the iron core based on electromagnetic steel sheets, but the strength limit is still at most about 780 N / mm2.
    [008] In this way, an attempt was made to obtain greater torque by increasing the rotational speed using the conventional rotor iron core made of electromagnetic steel plates when an IPM motor is miniaturized, there is a limit regarding the increase in rotational speed due to problems where the torque decreases in the high rotational speed range, even if field weakening control is performed, and the rotor can be damaged by the centrifugal force acting on the permanent magnet.
    [009] As a method to suppress damage to the iron core of the rotor because of the higher rotational speed, patent document 2, for example, proposes to increase the strength using a softening and hardening material for the iron core material of the rotor, and selectively temper only a joint portion near a permanent magnet insertion hole and in its vicinity. In addition, patent document 3, for example, proposes to use non-electromagnetic steel sheets, but a material with a high strength and a high density of magnetic saturation flux for the iron core material of the rotor. Patent document 1: Japanese patent application no. 2000-278900. Patent document 2: Japanese patent application no. 2009-153230. Patent document 3: Japanese patent application open no. 2009-46738.
    [0010] While developing steel plates for a rotor for high rotational speed, experimental IPM motors were manufactured using various steel plates as materials, evaluated the performance of the motors and, as a result, found that a large output torque can be obtained in a high rotational speed range where the field weakening control is performed by adjusting the coercivity of the base steel plates. With a higher output torque, the rotor can be operated at a higher rotational speed.
    [0011] In patent document 1, an attempt was made to decrease the electrical energy used for the control of field weakening by improving the shape of the magnet, but adjusting the coercivity of the base steel plates was not considered here. In patent documents 2 and 3 likewise, the adjustment of the coercivity of the base steel plates is not considered. In other words, in conventional configurations, the adjustment of the coercivity of the base steel plates is not considered, consequently, the output torque in a high speed range becomes small, and the maximum rotational speed correspondingly becomes low. DESCRIPTION OF THE INVENTION
    [0012] With the foregoing in view, it is an objective of the present invention to provide a rotor for an IPM motor and an IPM motor that can increase the output torque in a high speed range, and increase the maximum rotational speed.
    [0013] A rotor for an IPM engine according to the present invention includes: an iron core of the rotor, which is formed by laminating base steel sheets with a B8000 magnetic flux density of 1.65 T or more, measured at a magnetic field strength of 8,000 A / m and a coercivity of 100 A / m or more; a plurality of permanent magnet insertion holes that are formed with a space between each hole in the iron core of the rotor in a circumferential direction of the iron core of the rotor; and permanent magnets that are embedded in the permanent magnet insertion holes, respectively.
    [0014] In an IPM engine according to the present invention, the rotor is built-in.
    [0015] According to the rotor for an IPM engine of the present invention, the iron core of the rotor, which is formed by laminating base steel sheets with a B8000 magnetic flux density of 1.65 T or more, measured at a magnetic field strength of 8,000 A / m, and coercivity of 100 A / m or more is used, therefore, the output torque in the high speed range can be increased, and the maximum rotational frequency can be increased.
    [0016] Additionally according to the IPM motor of the present invention, which uses the aforementioned rotor, the output torque in the high speed range can be increased, and the maximum rotational frequency can be increased in the same way.
    [0017] In addition, the rotor for an IPM motor of the present invention is formed by rolling base steel sheets with a yield limit of 750 N / mm2 or more, therefore, the rotor is not damaged by the centrifugal force acting on the magnet permanent, even if the rotor is rotated at high speed. This allows for a decrease in the width of the bridge portion that is formed around the insertion holes of the permanent magnet. If the width of the bridge is smaller, the leakage of magnetic flux can be effectively reduced, which increases flexibility in the design of the rotor. In addition, permanent magnets can be miniaturized and, consequently, the cost of the motor can be drastically reduced. BRIEF DESCRIPTION OF THE DRAWINGS
    [0018] FIG. 1 is a front view representing a rotor for an IPM engine according to an embodiment of the present invention; FIG. 2 is a front view representing a rotor for an IPM engine that is different from the rotor in FIG. 1; FIG. 3 is a diagram representing a first rotor used to evaluate base steel sheets; FIG. 4 is a graph representing a relationship between the maximum torque at 15,000 rpm and the coercivity of the IPM engine using the base steel plates; FIG. 5 is a graph representing a relationship between the efficiency at 15,000 rpm and the coercivity of the IPM engine using the base steel plates; and FIG. 6 is a diagram representing a second rotor used to evaluate base steel sheets. BEST MODE FOR CARRYING OUT THE INVENTION
    [0019] Modalities of the present invention will now be described with reference to the drawings.
    [0020] FIG. 1 is a front view representing a rotor for an IPM engine according to an embodiment of the present invention. As illustrated in FIG. 1, the rotor 1 of the IPM engine includes: an iron core of the rotor 10 (main rotor body) which is formed by laminating the aforementioned steel sheets to a rotor (base steel sheets); a plurality of permanent magnet insertion holes 11 which are formed with a space between each hole in the iron core of the rotor 10 in a circumferential direction of the iron core of the rotor 10; and permanent magnets 12 which are embedded in the permanent magnet insertion holes 11, respectively. The IPM motor is configured with a stator (not shown) on an outer circumference of rotor 1.
    [0021] Each permanent magnet insertion hole 11 includes first and second insertion holes 11a and 11b which are arranged in a V shape whose apex faces a center of rotation 10a of the iron core of rotor 10, and a bridge 11c separating the first and second insertion holes 11a and 11b at the apex. The permanent magnet 12 is embedded in the first and second insertion holes 11a and 11b respectively. In other words, two permanent magnets 12 are embedded in a permanent magnet insertion hole 11.
    [0022] FIG. 2 is a front view representing a rotor 2 of an IPM motor which is different to the rotor of the IPM motor of FIG. 1. Construction elements that are the same or similar to the construction elements of rotor 1 in FIG. 1 are denoted by the same reference symbols. As illustrated in FIG. 2, the rotor 2 includes: an iron core of the rotor 10; a plurality of permanent magnet insertion holes 20 which is formed with a space between each hole in the iron core of the rotor 10 in a circumferential direction of the iron core of the rotor 10; and permanent magnets 21 which are respectively embedded in the permanent magnet insertion holes 20. Just like the iron core of rotor 10 of rotor 1 in FIG. 1, the iron core of the rotor 10 is formed by laminating the aforementioned base steel sheets.
    [0023] Each permanent magnet insertion hole 20 is arranged every 90o in the circumferential direction of the iron core of the rotor 10. Each permanent magnet insertion hole 20 is formed to have a linear shape, and a permanent magnet 21 is embedded in each permanent magnet insertion hole 20.
    [0024] In the case of an IPM engine using rotor 1 or 2 illustrated in FIG. 1 or FIG. 2, the field weakening control to suppress induced electromotive force is performed by generating a magnetic flux from the stator side in a direction of canceling the magnetic flux of the permanent magnets 12, when the IPM motor is operated in a high range rotational speed. The rated rotational speed of an IPM motor like this is 7,500 rpm when rotor 1 in FIG. 1 is used, and 10,000 rpm if rotor 2 in FIG. 2 is used. This field weakening control is performed in the high rotational speed range where the rated rotational speed is exceeded.
    [0025] The iron core of rotor 10 is formed by laminating base steel sheets with a B8000 magnetic flux density of 1.65 T or more, measured at a magnetic field strength of 8,000 A / m and a coercivity of 100 A / m or more.
    [0026] A B8000 magnetic field strength value of 1.65 T or more is to effectively use the reluctance torque based on the inductance difference between a position where permanent magnet 12 is inserted (d axis) and a position where the permanent magnet 12 is not inserted (q axis) when the rotor 1 rotates at high speed, and especially to demonstrate a torque performance equivalent to or greater than conventional steel sheets in the high speed rotational range.
    [0027] The reason why coercivity is 100 A / m or more is as follows. If the input current of a motor is increased, the output torque generally increases. However, it is known that, in the case of IPM motors, the q-axis inductance decreases and the reluctance torque drops, if the input current is increased because of the influence of the magnetic saturation of the iron core material, as described in “Bulletin of Department of Technology of Tokyo Gakugei University, Vol. 27, no. 1 (2004), pg 126 to 132 ”, for example. In other words, in the case of steel sheets for which coercivity is low, such as electromagnetic steel sheets, magnetic saturation is easily generated and therefore the reluctance torque cannot be increased immediately, even if the input current is increased. Although, in the case of using steel base plates from which coercivity is high, the drop in the reluctance torque can be suppressed, even if the input current value is relatively high, since magnetic saturation is not easily generated . As a result, the output torque and efficiency can be improved. Experimental IPM motors were manufactured using various steel plates as the material and evaluated the performance of the motors and, as a result, found that the energy consumption of the field weakening control, which is performed during high speed rotation, can be reduced and the output torque can be improved by forming the iron core of the rotor 10 using steel base plates with a coercivity of 100 A / m or more. However, if coercivity increases, the magnetic flux density tends to decrease, and sufficient reluctance torque can no longer be obtained when the magnetic flux density value B8000 becomes less than 1.65 T.
    [0028] It is preferable that the base steel sheets of the iron core of the rotor 10 have a yield limit of 750 N / mm2 or more. If the flow limit is in this range, the iron core of the rotor 10 can withstand the centrifugal force acting on the permanent magnets during high-speed rotation, and the rotor is not damaged, even in a high-speed rotational range. In addition, if the iron core of the rotor 10 of the present invention is used, the drop in torque is suppressed, even in the high speed rotational range, because the base steel plates outperform the field weakening control characteristics, therefore, a high performance engine that implements high speed rotation and high torque can be provided. As a result, the motor with the iron core of the rotor 10 can be used in various fields of application, including automobiles and household appliances.
    [0029] The bridge 11c formed in each permanent magnet insertion hole 11 of the rotor 1 in FIG. 1 is to ensure resistance around each permanent magnet insertion hole 11. The width of the bridge 11c (width of the bridge 11c located in the space between the first and second insertion holes 11a and 11b) can be reduced, causing the base steel sheets themselves have sufficient strength, whereby leakage of magnetic flux can be reduced. If it is possible to prevent damage to the rotor and decrease the leakage of magnetic flux, even if the width of the bridge 11c is smaller by increasing the resistance of the iron core of the rotor, to improve flexibility in the design of the rotor. In addition, the permanent magnet 12 can be miniaturized, as the leakage of magnetic flux is reduced, which means that the cost of the rotor can be drastically reduced. The output torque can be improved without miniaturizing the permanent magnet 12. The width of the bridge can be designed considering both the highest torque according to the realization of the high speed rotation and the miniaturization of the permanent magnet.
    [0030] The upper limit of the flow limit of the base steel plates of the iron core of the rotor 10 is 2,000 N / mm2. This is because the value of the magnetic flux density B8000 measured at the magnetic field strength of 8,000 A / m cannot be 1.65 T or more if the material with a yield limit above 2,000 N / mm2 is used. . EXAMPLES
    [0031] Steel sheets were made based on the iron core of the rotor 10 by the following manufacturing method A using each steel with the component compositions shown in table 1. Manufacturing Method A
    [0032] Each of the steels with the component compositions shown in table 1 were vacuum cast, their plates obtained by continuous casting were heated to 1,250 ° C, processed in finishing laminating at 950 ° C and wound at 560 ° C. As a result, hot-rolled steel sheets with a plate thickness of 1.8 mm were obtained. After carrying out acid cleaning of the hot-rolled steel sheets, cold-rolled steel strips with a sheet thickness of 0.35 mm were obtained by cold rolling once (final reduction: approximately 81%). Then, stress relief annealing processing (resistance limit; 100 N / mm2) was performed on the cold rolled steel strips obtained by passing the strips through a continuous oven set at 400 ° C for 60 seconds. Then, an insulating film, with a semi-organic composition with a thickness of approximately 1 μm, containing Cr oxide and Mg oxide, was formed on both sides of the steel sheets. Table 1
    Evaluation of base steel sheets manufactured by manufacturing method A
    [0033] JIS specimens no. 5 were extracted from the steel strips obtained to be used in the tensile test. In addition, ring-shaped specimens with an internal diameter of 33 mm and an external diameter of 45 mm were manufactured by punching to be used to measure magnetization. Table 2 shows the flow limit, resistance limit, flow rate (YR), magnetic flux density (B8000) measured when the magnetic field strength is 8,000 A / m and coercivity (Hc). Table 2

    [0034] Additionally, rotor 10 base steel sheets were manufactured by the following manufacturing method B, using steel with the component compositions shown in table 1. Manufacturing method B
    [0035] Each steel with the component compositions in table 1 was cast, and its continuous casting plates were heated to 1,250 ° C, subjected to finishing lamination at 850 ° C and wound at 560 ° C. As a result, hot-rolled steel sheets with a plate thickness of 1.8 mm were obtained. After carrying out acid cleaning of the hot-rolled steel sheets, cold-rolled steel sheets with a sheet thickness of 0.35 mm were obtained by performing cold rolling. The cold-rolled steel sheets obtained were heated to 900 ° C, passed in a Pb-Bi alloy bath adjusted to 250 ° C in order to cool to 250 ° C at an average cooling speed of 100 ° C / s and then without interruption, compression annealing was carried out, keeping the steel plates in an electric oven set at 400 ° C for 60 seconds. Then, an insulating film, with a semi-organic composition with a thickness of approximately 1 μm, containing Cr oxide and Mg oxide, was coated on both sides of the steel sheets. Evaluation of base steel sheets manufactured by manufacturing method B
    [0036] The same test of the aforementioned base steel sheets manufactured by manufacturing method A was performed for the base steel sheets manufactured by manufacturing method B. Table 3 shows the results. Table 3 Various characteristics of base steel sheets manufactured by manufacturing method B
    Subscribed indicates a value that does not meet the conditions specified in the present invention.
    [0037] In addition, steel plates based on the roto 10 were manufactured by the following manufacturing method C using steels with the component compositions shown in table 1. Manufacturing Method C
    [0038] Continuous casting steel plates nos. 1, 2, 3, 4 and 5 with the component compositions shown in table 1 were heated to 1,250 ° C in the same way as in manufacturing method A, subjected to finish laminating at 950 ° C and wound at 560 ° C. As a result, hot-rolled steel sheets with a plate thickness of 1.8 mm were obtained. After carrying out acid cleaning of the hot-rolled steel sheets, cold-rolled steel strips with a sheet thickness of 0.35 mm were obtained by cold rolling (final reduction: approximately 81%). Then, recrystallization annealing was carried out on the cold-rolled steel strips obtained by passing the strips through a continuous oven set at 800 ° C for 60 seconds. For cooling, the strip was cooled to 500 ° C to 8 ° C / s, and kept in the continuous oven set at 450 ° C for 120 s or more, as a super-aging process. Then, light cold lamination was performed with an elongation rate of 0.3% and then an insulating film with a semi-organic composition with a thickness of approximately 1 μm containing Cr oxide and Mg oxide was coated on both sides of the steel plates. Evaluation of base steel sheets manufactured by manufacturing method C
    [0039] The same test of the aforementioned base steel sheets manufactured by manufacturing methods A and B was performed for the base steel sheets manufactured by manufacturing method C. Table 4 shows the results. Table 4 Various characteristics of the base steel sheets manufactured by the manufacturing method C
    Underline indicates a value that does not meet the conditions specified in the present invention Evaluation as an IPM engine (with respect to magnetic flux density and coercivity)
    [0040] As shown in table 5, a first rotor with the structure of eight poles (pair of four poles) shown in FIG. 3 was manufactured by punching using steel no. 1, steel no. 3, steel no. 5 and steel no. 9 manufactured by manufacturing method A, steel no. 1, steel no. 2, steel no. 4, steel no. 6 and steel no. 7 manufactured by manufacturing method B, and steel no. 1, steel no. 2, steel no. 4 and steel no. 5 manufactured by manufacturing method C, and an engine performance evaluation test with a load torque was performed on the first rotor. For comparison, a rotor was also manufactured using conventional electromagnetic steel sheets (35A300) and evaluated in the same way. Only one stator was manufactured in combination with each mentioned manufactured rotor, and the performance of the motor was evaluated. The maximum output of all engines was 4.5 W. In this performance evaluation, field weakening control was performed at 10,000 rpm or more. The mechanical characteristics and magnetic characteristics evaluated for commercial electromagnetic steel sheets (35A300) using the same method as the base steel sheets of the present invention are as follows: Sheet thickness: 0.35 mm Flow limit: 381 N / mm2 Limit resistance: 511 N / mm2 B8000 saturation magnetic flux density: 1.76 T Coercivity: 75 A / m Table 5 IPM motor evaluation (magnetic flux density and coercivity)
    Underline indicates a value that does not satisfy the conditions specified in the present invention Specifications of the manufactured rotor and stator are as follows • Specifications of the first rotor Outside diameter: 80.1 mm Shaft length: 50 mm - Number of laminated layers: 0.35 mm / 140 layers - Width of central bridge and external bridge: 1.00 mm - Permanent magnet: neodymium magnet (NEOMAX - 38 VH). 9.0 mm wide x 3.0 mm thick x 50 mm long, embedded in a total of 16 locations. - Stator specifications - Clearance length: 0.5 mm - Outside diameter: 138.0 mm; breech thickness: 10 mm; length: 50 mm - Material of the iron core: electromagnetic steel sheets (35A300); plate thickness: 0.35 mm - Number of laminated layers: 140 layers - Winding method: distributed winding.
    [0041] Table 5 includes the maximum torque and efficiency of the engine at 15,000 rpm when each first rotor is installed. FIG. 4 shows the relationship between maximum torque at 15,000 rpm and coercivity, and FIG. 5 shows the relationship between efficiency at 15,000 rpm and coercivity. For this performance evaluation, also, field weakening control is performed at 10,000 rpm or more.
    [0042] Like table 5, FIG. 4 and FIG. 5 clarify, in the case of each motor enclosing a rotor in which the material of the iron core of the rotor is steel sheet with an Hc coercivity less than 100 A / m (electromagnetic steel sheets and steel no. 1 and steel no. 2 manufactured by the manufacturing method C), the torque at 15,000 rpm is low, less than 2.0 N, and the efficiency is also low, less than 60%. Whereas, in the case of each motor whose iron core of the rotor is of base steel plate with the magnetic flux density and coercivity in the range according to the present invention, a high torque above 2.0 Nm and a good efficiency of 60% or more can be implemented. Especially in a coercivity range of 300 A / m or more, an even greater torque of 2.5 N.m or more and a high efficiency of 70% or more can be implemented.
    [0043] In the case of steel no. 7 manufactured by manufacturing method B, with a high coercivity, but low density of magnetic flux B8000 of 1.61 T, the torque and efficiency are low because of the low density of magnetic flux. Evaluation as an IPM engine (bridge width and intensity)
    [0044] The second rotor shown in FIG. 6 using steel no. 4 (yield limit above 750 N / mm2) and steel no. 6 (with the highest yield limit) manufactured by manufacturing method B (these steels are called “ultra high strength steel sheets” here). Compared to the first rotor in FIG. 3, the bridge width of the second rotor in FIG. 6 was reduced by half in order to reduce the leakage of magnetic flux, and the size of the permanent magnet of the second rotor was reduced from 9.0 mm wide to 8.0 mm wide (approximately 11% miniaturized). In addition, the field weakening control was performed at 10,000 rpm or more.
    [0045] Specifications of the second rotor are as follows. The stator was the same aforementioned stator used for the evaluation of magnetic flux density and coercivity. • Specifications of the second external diameter rotor; 80.1 mm Shaft length; 50 mm - Number of laminated layers: 0.35 mm / 140 layers - Width of the central bridge and external bridge: 0.5 mm - Permanent magnet: neodymium magnet (NEOMAX - 38 VH), 8.0 mm wide x 3 .0 mm thick x 50 mm long, embedded in a total of 16 locations.
    [0046] For comparison, the first and second rotors were manufactured using electromagnetic steel sheets. Table 6 shows the maximum torque and efficiency of IPM rotors using a rotor made from electromagnetic steel sheets, and IPM rotors using a rotor made from steel no. 6 manufactured by manufacturing method B, operated at 5,000 rpm at 15,000 rpm. Table 6 Evaluation as an IPM engine (bridge width)

    [0047] As shown in table 6, if ultra-high strength steel plates are used for the iron core material of the rotor, a rotor with an engine performance equivalent to or better than that of a rotor in which the material of the rotor iron core is electromagnetic steel sheet is obtained, even if the width of the bridge is reduced, or if the permanent magnets are miniaturized as in the case of the second rotor. Especially in a high speed rotational range above 10,000 rpm, a good high torque characteristic can be obtained due to an improvement in field weakening control due to coercivity.
    [0048] In addition, the rotors used for the aforementioned test were removed from the stator and the steel cap attached, so the motor was connected to a load motor through a transmission and driven by the load side of the motor, and in this case state, an overspeed test, up to 50,000 rpm, was performed, and the rotational speed at which a rotor was damaged by centrifugal force was examined. Table 7 shows the results. Table 7 Evaluation as an IPM engine (resistance)

    [0049] As shown in table 7, in the case of the first rotor that uses electromagnetic steel plates as the rotor material and has a bridge width of 1.0 mm, the rotor was damaged at 40,450 rpm. On the other hand, if steel does not. 4 manufactured by manufacturing method B, which is an ultra-high strength steel sheet with a yield limit of 750 N / mm2 or more, is used as the rotor material, the first rotor did not break until 43,200 rpm, and even the second rotor, of which the width of the bridge was reduced to 0.5 mm, did not break until 36,000 rpm, which is equivalent to or greater than the first rotor made of electromagnetic steel. In the case of steel no. 6 manufactured by manufacturing method A, which has a yield limit of 950 N / mm2 or more, the second rotor with a bridge width of 0.5 mm did not break until 42,000 rpm and, in the case of steel no. 6 manufactured by manufacturing method B, which has a yield limit of 1,300 N / mm2 or more, the first rotor did not break even at 50,000 rpm. Thus, it has been confirmed that rupture can be prevented up to a higher rotational frequency than in the case of electromagnetic steel sheets, if ultra-high strength steel sheets of the present invention are used for the rotor material.
    [0050] Examining the damaged rotors, it was observed that both the portion of the internal bridge and the portion of the external bridge were deformed or ruptured, and that the permanent magnets fell from the rotors. The outer bridge portion is the portion where a permanent magnet insertion hole is close to the motor's periphery. Evaluation as an IPM engine (if using the rotor in FIG. 2)
    [0051] Rotor 2 (third rotor) shown in FIG. 2 using ultra-high strength steel plates, and conducted an engine performance evaluation test. A rotor using electromagnetic steel sheets was also manufactured and evaluated in the same way. The maximum output of the IPM 2 engine was 3.7 kW. Specifications of the manufactured rotor and stator are as follows. - Third rotor specifications Outside diameter: 80.0 mm Shaft length: 75 mm - Number of laminated layers: 0.35 mm / 210 layers - Bridge width: 3.0 mm - Permanent magnet: neodymium magnet (NEOMAX - 38 VH), 40.0 mm wide x 2.0 mm thick x 75 mm long, embedded in a total of 4 locations - Stator specifications - Clearance length: 0.5 - Outside diameter: 160.0 mm ; breech thickness: 17 mm; length: 75 mm - Material of the iron core: electromagnetic steel sheets (35A300); sheet thickness: 0.35 mm - Number of laminated layers: 210 layers - Winding method: distributed winding
    [0052] Table 8 shows the maximum torque and efficiency of IPM motors using each rotor operated in a range from 5,000 rpm to 12,000 rpm. The field weakening control was performed at a rotation frequency greater than 10,000 rpm. Table 8 Evaluation as an IPM engine (in the case of the rotor in FIG. 2)

    [0053] As shown in table 8, in the case of using electromagnetic steel plates, the motor can no longer rotate at 12,000 rpm, even if field weakening control is performed. In the case of the rotor using steel no. 6 with high coercivity, on the other hand, it is possible to rotate at 12,000 rpm, and it can be activated in a greater rotation range.
    权利要求:
    Claims (6)
    [0001]
    1. Rotor (1) for an IPM engine, the rotor being embedded in an IPM engine where a field weakening control is performed when the rotational speed exceeds a predetermined value, whose rotor (1) comprises: an iron core the rotor (10); a plurality of permanent magnet insertion holes (11), whose holes (11) are formed spaced apart from each other in the iron core of the rotor (10) in a circumferential direction of the iron core of the rotor (10); and, permanent magnets (12) that are embedded in the permanent magnet insertion holes (11), respectively, characterized by the fact that: the iron core of the rotor (10) is formed by laminating base steel sheets with a flow density magnetic B8000 of 1.65 T or more, measured at a magnetic field strength of 8,000 A / m and a coercivity of 100 A / m or more.
    [0002]
    2. Rotor (1) according to claim 1, characterized by the fact that the coercivity of the base steel plates is 300 A / m or more.
    [0003]
    Rotor (1) according to either of claims 1 or 2, characterized in that the flow limit of the base steel plates is 750 N / mm2 or more.
    [0004]
    Rotor (1) according to either of claims 1 or 2, characterized in that the yield limit of the base steel plates is 950 N / mm2 or more.
    [0005]
    Rotor (1) according to either of claims 1 or 2, characterized in that the flow limit of the base steel plates is 1,300 N / mm2.
    [0006]
    6. IPM engine, characterized by the fact that a field weakening control is carried out when the rotational speed exceeds a predetermined value, in which a rotor (1) as defined in any of claims 1 to 5 is embedded.
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    EP2693602A1|2014-02-05|
    KR101854491B1|2018-05-03|
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    AU2012233855B2|2016-04-14|
    BR112013023948A2|2016-12-13|
    CA2829872C|2016-09-06|
    MX2013011397A|2014-04-16|
    CA2829872A1|2012-10-04|
    EP2693602B1|2019-05-29|
    JP5186036B2|2013-04-17|
    KR20140039183A|2014-04-01|
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    法律状态:
    2018-12-18| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2019-08-20| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2020-06-30| B06A| Patent application procedure suspended [chapter 6.1 patent gazette]|
    2021-01-26| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2021-02-23| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 27/03/2012, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    JP2011-081215|2011-03-31|
    JP2011081214|2011-03-31|
    JP2011081215|2011-03-31|
    JP2011-081214|2011-03-31|
    JP2011264671A|JP5186036B2|2011-03-31|2011-12-02|IPM motor rotor and IPM motor using the same|
    JP2011-264671|2011-12-02|
    PCT/JP2012/057927|WO2012133404A1|2011-03-31|2012-03-27|Rotor for ipm motor, and ipm motor equipped with same|
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