rotating electrical machines

Abstract

This rotary electric machine has a rotor that comprises: a rotor core (8) having a shaft hole (12); a plurality of permanent magnets provided in an outer peripheral portion of the rotor core (8); a plurality of weight reduction holes (11) provided between the shaft hole (12) and the plurality of permanent magnets; a plurality of mass bodies (17) that have projections (18) at both end sections and that are inserted in the plurality of weight reduction holes (11); and a pair of end plates that are provided at both ends of the rotor core (8) and that have guide holes (19). The sliding of the projections (18) relative to the guide holes (19) guides the oscillation of the mass bodies (17) relative to the rotor core.

Description

[Technical Field]

[0001] The present disclosure relates to a rotating electric machine having end plates at both axial ends of a rotor core. [Background technology]

[0002] In rotating electric machines, torque ripple, a pulsating phenomenon, occurs due to the interaction of magnetic flux between the rotor and stator as the rotor rotates. As a result, vibration and noise are generated in the housing on which the rotating electric machine is mounted via the output shaft of the rotating electric machine. Reducing vibration and noise caused by torque ripple is an important issue when developing motors to be mounted on electric vehicles (EVs). As a result, one solution is to attach a centrifugal pendulum absorber (CPA), which can mechanically suppress vibration, to the rotating electric machine.

[0003] Patent Document 1 discloses a pendulum damper including a support member including two annular plates fixed to a rotor and a plurality of pendulum balance weights arranged between the annular plates of the support member. The two annular plates have openings serving as guide tracks with epicycloidal shapes, and guide rollers are engaged with the pendulum balance weights. The ends of the guide rollers are guided by the openings in the two annular plates, causing the pendulum balance weight to vibrate between the two annular plates of the support member. Patent Document 1 also discloses that, in order to incorporate the pendulum damper into the rotor structure, a portion of the rotor sheet metal assembly is cut out to provide an accommodation space for the pendulum balance weights, and the annular plates of the support member are arranged on both axial sides of the accommodation space. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2017-503462 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, multiple pendulum balance weights are provided in a partial axial region inside the rotor. In order to increase the weight of the pendulum balance weights to effectively reduce vibration and noise caused by torque ripple, it is necessary to increase the volume of the rotor, which poses a challenge in promoting the miniaturization of rotors and rotating electrical machines.

[0006] The present disclosure has been made in view of the above, and has an object to provide a rotating electric machine that can suppress vibrations and noise caused by torque ripple without increasing the volume of the rotor. [Means for solving the problem]

[0007] To solve the above-mentioned problems and achieve the object, the rotating electric machine of the present disclosure includes a rotor and a stator. The rotor includes a rotor core having a shaft hole, a plurality of permanent magnets provided on the outer periphery of the rotor core, a plurality of through holes provided between the shaft hole and the plurality of permanent magnets, a plurality of mass bodies having first guide bodies, which are either convex or concave portions, at both ends and inserted into the plurality of through holes, and a pair of end plates provided on both ends of the rotor core and having a plurality of second guide bodies, which are the other of the convex and concave portions. The sliding of the first guide bodies relative to the second guide bodies guides the oscillation of the mass bodies relative to the rotor core. [Effects of the Invention]

[0008] The rotating electric machine of the present disclosure has the advantage that vibrations and noise caused by torque ripple can be suppressed without increasing the volume of the rotor. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a drive train of an electric vehicle to which the rotating electric machines according to the first to fourth embodiments are applied. [Figure 2] FIG. 1 is a plan view showing the configuration of a rotating electric machine according to first to fourth embodiments; [Figure 3]FIG. 1 is an enlarged plan view showing a partially enlarged configuration of a rotating electric machine according to first to fourth embodiments. [Figure 4] FIG. 1 is a perspective view showing a configuration of a rotor of a rotating electric machine according to a first embodiment; [Figure 5] FIG. 1 is an enlarged view showing a configuration in which a part of a rotor of a rotating electric machine according to a first embodiment is enlarged; [Figure 6] FIG. 1 is a plan view showing a configuration of a rotor core of a rotating electric machine according to a first embodiment; [Figure 7] FIG. 1 is a perspective view showing a configuration of a pendulum mass body of a rotary electric machine according to a first embodiment; [Figure 8] FIG. 1 is a plan view showing a positional relationship between a weight reduction hole and a mass body of a rotating electric machine according to a first embodiment; [Figure 9] FIG. 10 is a plan view showing the configuration of a rotor core of a rotating electric machine according to a second embodiment. [Figure 10] FIG. 10 is a perspective view showing a configuration of an end plate of a rotating electric machine according to a second embodiment. [Figure 11] FIG. 11 is a perspective view showing the configuration of a pendulum mass body of a rotary electric machine according to a third embodiment. [Figure 12] FIG. 11 is a perspective view showing a configuration of an end plate of a rotating electric machine according to a third embodiment. [Figure 13] FIG. 10 is a perspective view showing the configuration of a rotor of a rotating electric machine according to a fourth embodiment. [Figure 14] FIG. 10 is a perspective view showing the configuration of a back surface of one end plate of a rotary electric machine according to a fourth embodiment, the back surface facing a rotor core; [Figure 15] FIG. 10 is a perspective view showing the configuration of the front surface of the other end plate of the rotating electric machine according to the fourth embodiment; [Figure 16] FIG. 10 is a plan view showing a partial configuration of a rear surface of one end plate of a rotating electric machine according to a fourth embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a rotating electric machine according to an embodiment will be described in detail with reference to the drawings.

[0011] Fig. 1 is a block diagram showing an example of the configuration of a drive train of an electric vehicle to which the rotating electric machines of Embodiments 1 to 4 are applied. The electric vehicle shown in Fig. 1 includes, as main components, a motor 1 as a rotating electric machine, a reduction gear 2, a drive shaft 3, a differential gear 4, and driving wheels 5. The motor 1 includes a rotor that functions as a pendulum damper.

[0012] The motor 1 rotates and generates motor torque when power is supplied from an inverter (not shown). The motor 1 is a synchronous motor whose rotor rotates in a rotating magnetic field of three-phase alternating current. The motor 1 has a rotor with embedded permanent magnets, a stator composed of electromagnets, and a motor case (not shown) that houses the stator and rotor. The reducer 2, located on the output side of the motor 1, transmits torque between the motor 1 and drive wheels 5. The reducer 2 is installed on the power transmission path between the motor 1 and drive wheels 5. The reducer 2 is a mechanism that can appropriately change the gear ratio, which is the ratio of the rotation speed of the output shaft to the rotation speed of the input shaft. The differential gear 4 is a differential device that detects the difference in rotation speed between the two drive wheels 5 and distributes the torque of the reducer 2 to each drive wheel 5. The differential gear 4 transmits the torque transmitted from the reducer 2 to the drive wheels 5. The drive wheels 5 are the wheels to which the drive torque output by the drive power source is transmitted and which generate the driving force of the electric vehicle.

[0013] FIG. 2 is a plan view showing the configuration of a rotating electric machine according to the first to fourth embodiments. FIG. 3 is an enlarged plan view showing the configuration of a portion of the rotating electric machine according to the first to fourth embodiments. FIGS. 2 and 3 show components common to the first to fourth embodiments. The motor 1 has a rotor 6 and a stator 7. The rotor 6 is disposed inside the stator 7. The torque generated by the motor 1 is amplified and attenuated by the connected reducer 2 and transmitted to the drive wheels 5. Therefore, torque ripple generated by the motor 1 is transmitted to the drive shaft 3, causing vibration and noise throughout the electric vehicle. The rotor 6 has a rotor core 8, permanent magnets 9, end plates, and a pendulum mass. The end plates and pendulum mass will be described later. The rotor core 8 may be formed of a laminate of electromagnetic steel sheets, or may be formed of other materials, such as a powder magnetic core formed by pressure molding of magnetic powder.

[0014] The motor 1 is an interior permanent magnet synchronous motor (IPMSM) in which permanent magnets 9 are embedded inside a rotor core 8. Therefore, a plurality of magnet insertion holes 10 for embedding a plurality of permanent magnets 9 are provided on the outer periphery of the rotor core 8. The rotor core 8 is provided with a shaft hole 12 through which a shaft (not shown) that connects the motor 1 and the reducer 2 passes. The rotor core 8 also has a plurality of weight-reducing holes 11, which are through-holes that reduce the weight of the rotor core 8 and improve the magnetic flux density while maintaining strength sufficient to withstand the centrifugal force generated in the rotor core 8 and the permanent magnets 9. The weight-reducing holes 11 are provided between the plurality of permanent magnets 9 and the shaft hole 12. Each of the weight-reducing holes 11 is a through-hole. 3, between two circumferentially adjacent permanent magnets 9 between the magnetic poles of rotor core 8, there are provided inter-pole bridges 13 extending radially inward from the outer peripheral surface of rotor core 8, and inter-pole gaps (flux barriers) 14, which are gaps for preventing magnetic flux short circuits. Inter-pole gaps 14 are gaps formed in magnet insertion holes 10, and the tip ends of inter-pole gaps 14 are rounded, for example, in the shape of a semi-ellipse 15.

[0015] Embodiment 1 Fig. 4 is a perspective view showing the configuration of rotor 6 of the rotating electric machine according to the first embodiment. Fig. 5 is an enlarged view showing the configuration of a part of rotor 6 of the rotating electric machine according to the first embodiment. Fig. 5 shows an enlarged view of part V of Fig. 4. Fig. 6 is a plan view showing the configuration of rotor core 8 of the rotating electric machine according to the first embodiment. Fig. 7 is a perspective view showing the configuration of pendulum mass body 17 of the rotating electric machine according to the first embodiment.

[0016] As shown in Figure 4, the rotor 6 has a rotor core 8 and a pair of end plates 16. The end plates 16 are arranged at both ends of the rotor core 8 to prevent misalignment of the rotor core 8 and the permanent magnets 9 and to ensure rotational balance of the rotor core 8. The end plates 16 are provided with a shaft hole 20 for passing the shaft therethrough, and the inner diameter of the shaft hole 20 matches the inner diameter of the shaft hole 12 of the rotor core 8. To prevent the shaft, rotor core 8, and end plates 16 from separating due to rotation, these components are fixed by press fitting, but they may also be fixed with a key structure.

[0017] The end plate 16 is made of a non-magnetic material to reduce its effect on the magnetic flux. The end plate 16 has guide holes 19 as second guide bodies for determining the swing path of a pendulum mass body 17 (described later) provided in the rotor core 8. In the case of FIG. 4, the guide holes 19 are through holes. The guide holes 19 may also be blind holes with a bottom. Through holes and blind holes are collectively referred to as recesses. A plurality of guide holes 19 are arranged along the circumferential direction of the end plate 16. Specifically, the guide holes 19 are arranged in multiple pairs, as shown in FIG. 5.

[0018] As shown in FIG. 6 , a pendulum mass 17 is embedded in the weighting hole 11 of the rotor core 8. The pendulum mass 17 is also simply referred to as the mass 17. As shown in FIG. 7 , the mass 17 includes a weight 21 and a protrusion 18. The weight 21 has a length that corresponds, for example, to the entire axial length of the weighting hole 11, which is a through-hole. Both ends of the mass 17 inserted into the weighting hole 11 have protrusions 18 as first guide bodies that restrain the swing path in the guide holes 19 of the end plates 16. The protrusions 18, which are convex portions, are fixed to the weight 21 and have, for example, a cylindrical shape. The protrusions 18 may have any other shape, such as a hexagonal prism. The protrusions 18 may also have a fixed shaft or a rotatable central axis.

[0019] As shown in FIGS. 5 to 7 , each mass body 17 is provided with two protrusions 18 on each side to prevent rotational movement of the mass body 17 around its axis and to promote sliding of the mass body 17. Furthermore, pairs of guide holes 19, each paired with a mass body 17 having two protrusions 18 on one side, are arranged in the circumferential direction on the end plate 16, the same number as the number of mass bodies 17. Furthermore, the pairs of guide holes 19 are arranged so as to be mirror-symmetrical with respect to a radial line passing through the centers of the pairs of guide holes 19. Note that if rotation of the mass body 17 around its axis is permitted, one protrusion 18 may be arranged on each side of each mass body 17. Furthermore, if the aforementioned rotation is permitted, the cross section of the protrusions 18 is not limited to a circular shape, and may be any curved or polygonal shape.

[0020] FIG. 8 is a plan view showing the positional relationship between weight reduction hole 11 and mass body 17 of the rotating electric machine according to the first embodiment. As shown in FIGS. 7 and 8 , the cross-sectional shape of weight portion 21 of mass body 17 is similar to the cross-sectional shape of weight reduction hole 11. This is to increase the inertia of mass body 17. Regardless of the shape of mass body 17, the cross-sectional shapes of weight portion 21 and weight reduction hole 11 are set so that a gap is formed between mass body 17 and the inner wall of weight reduction hole 11 in rotor core 8 at all positions along its orbit, as shown in FIG. 8 . If there is no gap between mass body 17 and the inner wall of weight reduction hole 11, nonlinear behavior caused by a collision not only prevents the desired vibration damping effect from being obtained, but also may cause abnormal noise and deformation of rotor core 8.

[0021] It is desirable to set the axial length L1 of weight portion 21 of mass body 17 shorter than the axial length Lr of rotor core 8, and to design the overall length Lt of pendulum mass body 17 including protrusions 18 to be slightly smaller than Lr+2Lp, which is the total length of axial length Lr of rotor core 8 and thickness Lp of end plates 16 connected to both ends of the rotor core 8. This prevents interference with reducer 2, the motor case, etc.

[0022] Mass body 17 is made of a non-magnetic material to reduce its effect on the magnetic flux. Mass body 17 may be made of a magnetic material (conductor), in which case, when mass body 17 moves to a position of high magnetic flux density due to the action of electromagnetic induction, a damping effect is produced, preventing excessive displacement of weight portion 21 and suppressing abnormal noise that occurs when protrusion 18 comes into contact with the end of guide hole 19.

[0023] The radius of the oscillation orbit of the mass body 17 is determined by the rotation order that causes cogging torque or torque ripple vibration, which corresponds to the number of pole pairs of the motor 1. The oscillation orbit of the mass body 17 may be a circular orbit, or may be determined by a higher-order function to prevent unstable behavior of the pendulum. When the oscillation orbit of the mass body 17 is a circular orbit, in a rotating electric machine formed by a three-phase AC synchronous motor, the rotation radius L of the oscillation orbit of the mass body 17 and the distance R between the rotation center of the oscillation orbit of the mass body 17 and the center of the rotor core 8 are set so that the effective rotation order that produces the effect as a vibration absorber matches the frequency obtained by multiplying the number of pole pairs N of the permanent magnet 9 by the sixth-order frequency component, which is the frequency component of the main torque ripple in the three-phase AC synchronous motor. In other words, the rotation radius L and the distance R are determined by the number of pole pairs N of the permanent magnet 9 embedded inside the rotor core 8, using the equation R / L=(6N) 2 By setting the frequency of the pendulum in accordance with the above formula, it is possible to suppress torsional vibration caused by torque ripple of a three-phase AC synchronous motor, which is said to have a sixth-order rotational component. In this way, by matching the natural frequency of the pendulum with the resonance point of the torsional vibration of the drive system, in other words, by suppressing vibration at 6 × (number of pole pairs N), which is the frequency component of the torque ripple generated in a three-phase AC synchronous motor, it is possible to avoid the resonance point that depends on the rotation speed of the rotor 6.

[0024] Cogging is a pulsating torque caused by the magnetic field generated between the rotor core 8 and permanent magnet 9 when the motor 1 is not energized, and its magnitude is constant regardless of the current when the motor 1 is energized, and it is generally known that the lower the rotation speed of the motor 1, the greater the pulsating torque, and that as the rotation speed increases, the inertial force acting on the rotor core 8 increases, resulting in a relative decrease in pulsating torque. Torque ripple corresponds to the fluctuation in electromagnetic torque generated by the field magnetic flux of the permanent magnet 9 and the current in the coil when the motor 1 is energized, and its magnitude is said to be proportional to the current.

[0025] Furthermore, the centers of the weight-reducing holes 11 are positioned so as to overlap the d-axis or q-axis and not interfere with the magnet insertion holes 10 into which the permanent magnets 9 are inserted. If the centers of the weight-reducing holes 11 are not positioned on the d-axis or q-axis, the distribution of the interlinkage magnetic flux will be asymmetric with respect to the d-axis and q-axis, increasing the spatial harmonic components of the magnetic flux. This will increase iron loss, radial electromagnetic force, and torque ripple. To prevent this, the centers of the weight-reducing holes 11 are positioned so as to overlap the d-axis or q-axis.

[0026] As described above, according to the first embodiment, rotor core 8 is provided with weight-reducing holes 11, which are through-holes, mass body 17 is arranged so as to penetrate rotor core 8, protrusions 18 are provided at both ends of mass body 17 as first guide bodies, end plate 16 is provided with guide holes 19 as second guide bodies, and the sliding of protrusions 18 relative to guide holes 19 guides the oscillation of mass body 17 relative to rotor core 8. Therefore, vibration and noise due to torque ripple can be suppressed without increasing the volume of rotor 6.

[0027] Embodiment 2 Fig. 9 is a plan view showing the configuration of rotor core 8 of a rotating electric machine according to the second embodiment. Fig. 10 is a perspective view showing the configuration of end plate 32 of a rotating electric machine according to the second embodiment. In the second embodiment, mass body 17 of the first embodiment is replaced with mass body 30, and end plate 16 of the first embodiment is replaced with end plate 32. Other configurations in the second embodiment are the same as those in the first embodiment, and therefore redundant explanations will be omitted.

[0028] In the second embodiment, as shown in Fig. 9, guide grooves 31, which are recesses that define the swing path, are provided at both ends of each mass body 30. The guide grooves 31 correspond to first guide bodies. Also, as shown in Fig. 10, a plurality of projections 33, which are convex portions, are provided intermittently in the circumferential direction on each end plate 32. The projections 33 correspond to second guide bodies. In the second embodiment, one projection 33 is provided corresponding to each guide groove 31, and each projection 33 slides within its corresponding guide groove 31.

[0029] With this configuration, mass body 30 slides and simultaneously rotates about the axis of protrusion 33. The axis of protrusion 33 is eccentric and offset from the center of gravity (center) of mass body 30. If guide groove 31 were provided radially outward from the center position of mass body 30, there is a possibility that mass body 30 would collide with the inner wall of weight-reducing hole 11 when it rotates about its axis. To prevent this, according to the second embodiment, guide groove 31 is provided radially inward from the center position of mass body 30.

[0030] According to embodiment 2, the guide grooves 31 are provided radially inward from the center position of the mass body 30, so that even if one protrusion 33 is provided corresponding to each guide groove 31, interference with the weight-reducing holes 11 due to rotation of the mass body 30 can be prevented.

[0031] Embodiment 3 Fig. 11 is a perspective view showing the configuration of a pendulum mass body 41 of a rotating electric machine according to a third embodiment. Fig. 12 is a perspective view showing the configuration of an end plate 46 of the rotating electric machine according to the third embodiment. As shown in Fig. 11, pendulum mass body 41 includes a first mass body 41a having a weight portion 43a with protrusions 42a as first protrusions at both ends, a second mass body 41b having a weight portion 43b having protrusions 42b as second protrusions at both ends, and a connecting member 45 connecting protrusions 42a and 42b. First mass body 41a is inserted into weight-reducing hole 11 as a first through hole, and second mass body 41b is inserted into weight-reducing hole 11 as a second through hole.

[0032] As shown in FIG. 12 , end plate 46 is formed with two guide holes 47, which are through holes that guide two protrusions 42a, 42b of pendulum mass body 41, and a recess 48, which connects the two guide holes 47 and serves as a third recess for accommodating connecting member 45 of pendulum mass body 41. One of the two guide holes 47 corresponds to the first recess, and the other corresponds to the second recess. End plate 46 is provided with four sets of configurations, each with two guide holes 47 and a recess 48, to support four pendulum mass bodies 41. Other configurations in embodiment 3 are similar to those in embodiment 1, and redundant description will be omitted. Note that three or more weights may be connected to pendulum mass body 41. Although lightening holes 11 in embodiment 3 are not shown, they are preferably shaped similarly to the cross-sectional shapes of weights 43a, 43b, as with lightening holes 11 in embodiment 1.

[0033] In this configuration, the protrusion 42a of the first mass 41a and the protrusion 42b of the second mass 41b are connected by a connecting member 45 to form a single pendulum mass 41. The connecting member 45 connects the tips of the protrusions 42a and 42b of the first mass 41a and the second mass 41b to each other. The connecting member 45 prevents the mass 41 from rotating around the protrusions 42a and 42b. Furthermore, as shown in FIGS. 4 and 8, if two guide holes 19 can be arranged corresponding to one weight-reducing hole 11, rotation of the mass 41 can be prevented. However, even if only one guide hole 19 can be arranged corresponding to one weight-reducing hole 11, this configuration can prevent rotation of the mass 41 and promote sliding of the mass 41.

[0034] Furthermore, the recess 48 provided in the end plate 46 prevents the connecting member 45 from being exposed. The pair of guide holes 47 are arranged mirror-symmetrically with respect to a radial line passing through the middle between the pair of guide holes 47. This allows the mass body 41 to perform pendulum motion while the positional relationship between the axes of the two protrusions 42a, 42b is fixed.

[0035] According to the third embodiment, the pendulum mass body 41 is formed by connecting the first mass body 41a and the second mass body 41b with the connecting member 45, so that the rotation of the mass body 41 can be prevented and the sliding of the mass body 41 can be promoted.

[0036] Embodiment 4 FIG. 13 is a perspective view showing the configuration of the rotor 6 of the rotating electric machine of the fourth embodiment. FIG. 14 is a perspective view showing the configuration of the back surface of one end plate 51 of the rotating electric machine of the fourth embodiment, facing the rotor core 8. FIG. 15 is a perspective view showing the configuration of the front surface of the other end plate 56 of the rotating electric machine of the fourth embodiment. FIG. 16 is a plan view showing a partial configuration of the back surface of one end plate 51 of the rotating electric machine of the fourth embodiment. In the fourth embodiment, the one end plate 32 of the rotating electric machine of the second embodiment is replaced with the end plate 51, and the other end plate 32 of the rotating electric machine of the second embodiment is replaced with the end plate 56. Other configurations of the fourth embodiment are the same as those of the second embodiment, and redundant description will be omitted. That is, in the rotating electric machine of FIGS. 13 to 16, a plurality of protrusions 52 are arranged in the circumferential direction on the end plates 51 and 56, and the rotor core 8 shown in FIG. 13 is provided with a plurality of mass bodies 30 having a plurality of weight-reducing holes 11 and a plurality of guide grooves 31, as shown in FIG. 9. In this way, the protrusions 52 of the fourth embodiment correspond to the protrusions 33 of the second embodiment.

[0037] 13, an end plate 51 is disposed at one end of rotor core 8, and an end plate 56 is disposed at the other end of rotor core 8. End plate 51 has flow passages 53 for supplying lubricating oil to protrusions 52 and guide grooves 31, and end plate 56 has discharge holes 57 and 58 for discharging the lubricating oil supplied from end plate 51. The lubricating oil may contain a coolant in addition to a lubricant.

[0038] As shown in FIG. 14 , flow paths 53 are formed on the rear surface of end plate 51 as oil grooves. Flow paths 53 reduce contact friction between protrusions 52 engaged with guide grooves 31 and allow lubricating oil to flow, cooling rotor core 8 as a whole. Flow paths 53 include multiple grooves 53a extending from shaft holes 20 on the inner periphery of end plate 51 to protrusions 52, and multiple grooves 53b branching from protrusions 52 and extending to the outer periphery of end plate 51. Ends of multiple grooves 53b are located at positions corresponding to inter-pole gaps 14 formed in rotor core 8. Lubricating oil flowing in from shaft holes 20 flows into protrusions 52 and guide grooves 31 via multiple grooves 53a, as shown by the arrows in FIG. 16 , and some of the lubricating oil flows into weight-saving holes 11 of rotor core 8 into which mass bodies 30 are inserted. The remaining lubricating oil flows through groove 53b while branching as shown by the arrows in FIG. 16, reaches tip end 55 of groove 53b, and then flows into inter-pole gap 14 of rotor core 8.

[0039] 13 and 15 , end plate 56 has a plurality of discharge holes 57 provided at positions corresponding to a plurality of lightening holes 11 of rotor core 8, and a plurality of discharge holes 58 provided at positions corresponding to a plurality of inter-pole gaps 14 of rotor core 8. Lubricating oil that flows from one end plate 51 into lightening holes 11 of rotor core 8 is discharged from discharge holes 57 of end plate 56. Lubricating oil that flows from one end plate 51 into inter-pole gaps 14 of rotor core 8 is discharged from discharge holes 58 of end plate 56.

[0040] As rotor core 8 rotates, the lubricating oil inside weight reduction holes 11 is subjected to centrifugal force and flows out from the radially outer inner wall. For efficient discharge, therefore, it is desirable to position discharge holes 57 radially outward of weight reduction holes 11. In the above configuration, the lubricating oil is discharged radially outward of rotor core 8, but a flow path configuration may also be used in which the lubricating oil is recovered toward shaft hole 20.

[0041] According to embodiment 4, an oil groove is provided to supply lubricating oil to the guide groove 31 and the protrusion 52 to dissipate frictional heat, thereby reducing the frictional heat between the guide groove 31 and the protrusion 52 and promoting smooth swinging motion of the mass body 30.

[0042] The configurations shown in the above embodiments are examples of the contents of the present disclosure, and may be combined with other known technologies, and parts of the configurations may be omitted or modified within the scope of the gist of the present disclosure. [Explanation of symbols]

[0043] 1 motor, 2 reducer, 3 drive shaft, 4 differential gear, 5 drive wheel, 6 rotor, 7 stator, 8 rotor core, 9 permanent magnet, 10 magnet insertion hole, 11 lightening hole, 12, 20 shaft hole, 13 interpole bridge, 14 interpole gap, 15 semi-elliptical shape, 16, 32, 46, 51, 56 end plate, 17, 30, 41 pendulum mass (mass), 18, 33, 42a, 42b, 52 protrusion, 19, 47 guide hole, 21, 43a, 43b weight portion, 31 guide groove, 41a first mass, 41b second mass, 45 connecting member, 48 recess, 53 flow path, 53a, 53b groove, 55 tip portion, 57, 58 discharge hole.

Claims

1. A rotor and a stator are provided, The rotor is a rotor core having a shaft hole; a plurality of permanent magnets provided on the outer periphery of the rotor core; a plurality of through holes provided between the shaft hole and the plurality of permanent magnets; a plurality of mass bodies each having a first guide body that is one of a convex portion and a concave portion at both ends and inserted into the plurality of through holes; a pair of end plates provided at both ends of the rotor core, the end plates having a plurality of second guide bodies which are the other of the convex portions and the concave portions; The sliding of the first guide body relative to the second guide body guides the swinging of the mass body relative to the rotor core. A rotating electric machine characterized by:

2. When the number of pole pairs of the permanent magnet is N, the radius of rotation L of the swing orbit of the mass body and the distance R between the center of rotation of the swing orbit of the mass body and the center of the rotor core are set according to the following equations: R / L = (6N)2 2. The rotating electrical machine according to claim 1.

3. The end plate has an oil groove for allowing lubricating oil to flow to the first guide body of the mass body and the second guide body of the end plate.

2. The rotating electrical machine according to claim 1.

4. The center of the through hole is located at a position overlapping with the d-axis or the q-axis.

2. The rotating electrical machine according to claim 1.

5. the mass body includes a first mass body inserted into the first through hole and having first convex portions at both ends, a second mass body inserted into the second through hole and having second convex portions at both ends, and a connecting member connecting the first convex portions and the second convex portions, The pair of end plates each include a first recess in which the first protrusion slides and a second recess in which the second protrusion slides, The first recess and the second recess are arranged in mirror symmetry with respect to a radial line passing through the centers of the first recess and the second recess.

2. The rotating electrical machine according to claim 1.

6. The pair of end plates includes a third recess that connects the first recess and the second recess and receives the connecting member.

6. The rotating electrical machine according to claim 5.

7. Each of the first guide bodies and each of the second guide bodies has one convex portion or one concave portion, 2. The rotating electric machine according to claim 1, wherein the first guide body and the second guide body are disposed radially inward from a center position of the mass body.

8. Each of the first guide bodies and each of the second guide bodies have two protrusions or two recesses, The two recesses are arranged mirror-symmetrically with respect to a radial line passing through the centers of the two recesses.

2. The rotating electrical machine according to claim 1.

9. The total length of the mass body is equal to or less than the combined length of the axial length of the rotor core and the thickness of the pair of end plates.

9. The rotating electric machine according to claim 1, wherein the rotating electric machine comprises: a rotor;

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