WO2024095320A1

WO2024095320A1 - Rotary electric machine

Info

Publication number: WO2024095320A1
Application number: PCT/JP2022/040740
Authority: WO
Inventors: 健二岩田; 甲彰山根
Original assignee: 三菱電機株式会社
Priority date: 2022-10-31
Filing date: 2022-10-31
Publication date: 2024-05-10

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

Rotating Electric Machine

This disclosure relates to a rotating electric machine having end plates at both axial ends of a rotor core.

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 in which the rotating electric machine is mounted via the output shaft of the rotating electric machine. When developing motors to be mounted in EVs (Electric Vehicles), reducing vibration and noise caused by torque ripple is an important issue. For this reason, one measure is to attach a centrifugal pendulum absorber (CPA), which can mechanically suppress vibration, to the rotating electric machine.

Patent Document 1 shows 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 as guide tracks having an epicycloidal shape, and a guide roller is engaged with the pendulum balance weight. The end of the guide roller is guided by the openings of the two annular plates, so that the pendulum balance weight vibrates between the two annular plates that are the support members. Patent Document 1 also shows that in order to incorporate the pendulum damper into the rotor structure, a part of the assembly of sheet metal of the rotor is cut out to provide an accommodation space for the pendulum balance weight, and the annular plates of the support member are arranged on both axial sides of the accommodation space.

JP 2017-503462 A

In Patent Document 1, multiple pendulum balance weights are provided in a portion of the axial area of the rotor, so 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.

This disclosure was made in consideration of the above, and aims to provide a rotating electric machine that can suppress vibrations and noise caused by torque ripple without increasing the volume of the rotor.

In order to solve the above 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 a first guide body which is one of a convex portion and a concave portion 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 portions and the concave portions. The oscillation of the mass bodies relative to the rotor core is guided by the sliding of the first guide body relative to the second guide body.

The rotating electric machine disclosed herein has the advantage of being able to suppress vibrations and noise caused by torque ripple without increasing the volume of the rotor.

FIG. 1 is a block diagram showing a configuration example of a drive train of an electric vehicle to which the rotating electric machine according to the first to fourth embodiments is applied; FIG. 1 is a plan view showing a configuration of a rotating electric machine according to first to fourth embodiments; FIG. 1 is an enlarged plan view showing a configuration in which a part of a rotating electric machine according to first to fourth embodiments is enlarged. FIG. 1 is a perspective view showing a configuration of a rotor of a rotating electric machine according to a first embodiment; 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; FIG. 1 is a plan view showing a configuration of a rotor core of a rotating electric machine according to a first embodiment; FIG. 1 is a perspective view showing a configuration of a pendulum mass body of a rotating electric machine according to a first embodiment; 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; FIG. 11 is a plan view showing a configuration of a rotor core of a rotating electric machine according to a second embodiment of the present invention; FIG. 11 is a perspective view showing a configuration of an end plate of a rotating electric machine according to a second embodiment; FIG. 11 is a perspective view showing a configuration of a pendulum mass body of a rotating electric machine according to a third embodiment; FIG. 13 is a perspective view showing a configuration of an end plate of a rotating electric machine according to a third embodiment; FIG. 13 is a perspective view showing a configuration of a rotor of a rotating electric machine according to a fourth embodiment. FIG. 13 is a perspective view showing a configuration of a back surface of one end plate of a rotating electric machine according to a fourth embodiment, the back surface facing a rotor core; FIG. 13 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; FIG. 13 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;

The rotating electric machine according to the embodiment will be described in detail below with reference to the drawings.

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 machine of embodiments 1 to 4 is applied. The electric vehicle shown in FIG. 1 has, as its 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 has a rotor that functions as a pendulum damper.

The motor 1 rotates by receiving power from an inverter (not shown) and generates motor torque. The motor 1 is a synchronous motor whose rotor rotates in a rotating magnetic field of three-phase AC. The motor 1 has a rotor with a permanent magnet embedded therein, a stator made of an electromagnet, and a motor case (not shown) that houses the stator and rotor. The reducer 2 arranged on the output side of the motor 1 transmits torque between the motor 1 and the drive wheels 5. The reducer 2 is provided between the motor 1 and the drive wheels 5 on the power transmission path. 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 the rotation speed of the two drive wheels 5 and distributes and transmits 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 wheels to which the drive torque output by the drive power source is transmitted and which generate the drive force of the electric vehicle.

FIG. 2 is a plan view showing the configuration of the rotating electric machine of the first to fourth embodiments. FIG. 3 is an enlarged plan view showing the configuration of a part of the rotating electric machine of the first to fourth embodiments. FIG. 2 and FIG. 3 show the components common to the first to fourth embodiments. The motor 1 has a rotor 6 and a stator 7. The rotor 6 is arranged 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, the torque ripple generated by the motor 1 is transmitted to the drive shaft 3, causing vibration and noise in the entire electric vehicle. The rotor 6 has a rotor core 8, a permanent magnet 9, an end plate, and a pendulum mass body. The end plate and the pendulum mass body will be described later. The rotor core 8 may be made of a laminate of electromagnetic steel sheets, or may be made of other materials such as a powder core made by pressure molding of magnetic powder.

The motor 1 is an interior permanent magnet synchronous motor (IPMSM) with permanent magnets 9 embedded inside the rotor core 8. For this reason, the rotor core 8 has a plurality of magnet insertion holes 10 for embedding the plurality of permanent magnets 9 on its outer periphery. The rotor core 8 has 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 reduction holes 11, which are through holes for reducing the weight of the rotor core 8 and improving the magnetic flux density while maintaining the strength to withstand the centrifugal force generated in the rotor core 8 and the permanent magnets 9. The weight reduction holes 11 are provided between the plurality of permanent magnets 9 and the shaft hole 12. Each weight reduction hole 11 is a through hole. As shown in FIG. 3, between the two circumferentially adjacent permanent magnets 9 between the magnetic poles of the rotor core 8, there is an interpole bridge 13 extending radially inward from the outer circumferential surface of the rotor core 8, and an interpole gap (flux barrier) 14, which is a gap for preventing magnetic flux short circuits. The interpole gap 14 is a gap formed in the magnet insertion hole 10, and the tip of the interpole gap 14 is rounded, for example, in a semi-elliptical shape 15.

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

As shown in FIG. 4, the rotor 6 has a rotor core 8 and a pair of end plates 16. The end plates 16 are disposed at both ends of the rotor core 8 to prevent misalignment of the rotor core 8 and the permanent magnets 9 and to ensure the rotational balance of the rotor core 8. The end plates 16 are provided with a shaft hole 20 for passing the shaft through, 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 from being separated from the rotor core 8 and the end plates 16 due to rotation, these components are fixed by press fitting, but they may also be fixed with a key structure.

The end plate 16 is made of a non-magnetic material to reduce the effect on the magnetic flux. The end plate 16 has a guide hole 19 as a second guide body for determining the swing trajectory of the pendulum mass body 17 (described later) provided in the rotor core 8. In the case of FIG. 4, the guide hole 19 is a through hole. The guide hole 19 may also be a blind hole with a bottom. Through holes and blind holes are collectively referred to as a recess. 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 sets of two as shown in FIG. 5.

As shown in FIG. 6, a pendulum mass 17 is embedded in the weight reduction hole 11 of the rotor core 8. The pendulum mass 17 is also simply called the mass 17. As shown in FIG. 7, the mass 17 includes a weight portion 21 and a protrusion 18. The weight portion 21 has a length that is, for example, the entire axial length of the weight reduction hole 11, which is a through hole. Both ends of the mass 17 inserted into the weight reduction hole 11 have protrusions 18 as first guide bodies for restraining the swing trajectory in the guide hole 19 of the end plate 16. The protrusion 18, which is a convex portion, is fixed to the weight portion 21 and has, for example, a cylindrical shape. The protrusion 18 may have any other shape, such as a hexagonal column. The protrusion 18 may also have a fixed axis or a central axis that can rotate freely.

As shown in Figs. 5 to 7, two protrusions 18 are provided on each side of each mass body 17 to suppress rotational movement of the mass body 17 around its axis and promote sliding of the mass body 17. Also, pairs of guide holes 19, which are paired with the mass body 17 having two protrusions 18 on one side, are arranged in the circumferential direction on the end plate 16 in the same number as the mass body 17. Also, the pair of guide holes 19 are arranged so as to be mirror-symmetrical with respect to a radial line passing through the center of the pair of guide holes 19. Note that, in the case where rotation of the mass body 17 around the axis of the mass body 17 is permitted, one protrusion 18 may be arranged on each side of each mass body 17. Also, in the case where the above-mentioned 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.

FIG. 8 is a plan view showing the positional relationship between the weight reduction hole 11 and the mass body 17 of the rotating electric machine of the first embodiment. As shown in FIGS. 7 and 8, the cross-sectional shape of the weight portion 21 of the mass body 17 is similar to the cross-sectional shape of the weight reduction hole 11. This is to increase the inertia of the mass body 17. Whatever the shape of the mass body 17, the cross-sectional shapes of the weight portion 21 and the weight reduction hole 11 are set so that a gap is generated between the mass body 17 and the inner wall of the weight reduction hole 11 of the rotor core 8 at all positions on the orbit, as shown in FIG. 8. If there is no gap between the mass body 17 and the inner wall of the weight reduction hole 11, not only will the desired vibration damping effect not be obtained due to nonlinear behavior caused by a collision, but abnormal noise may also be generated and the rotor core 8 may be deformed.

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

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

The orbit radius of the swing orbit of the mass body 17 is determined by the order of rotation that causes the cogging torque or torque ripple vibration according to the number of pole pairs of the motor 1. The swing 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 swing orbit of the mass body 17 is a circular orbit, the rotation radius L of the swing orbit of the mass body 17 and the distance R between the center of rotation of the swing 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 in a rotating electric machine composed of a three-phase AC synchronous motor coincides with the frequency obtained by multiplying the number of pole pairs N of the permanent magnet 9 by the sixth order frequency component that is the main frequency component of the torque ripple of the three-phase AC synchronous motor. In other words, by determining the rotation radius L and the distance R according to the equation R/L=(6N) ² that is determined by the number of pole pairs N of the permanent magnet 9 embedded inside the rotor core 8, it is possible to suppress the torsional vibration caused by the torque ripple of the three-phase AC synchronous motor that is considered to have the sixth order rotation 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 the vibration at 6 × (number of pole pairs N), which is the frequency component of the torque ripple generated in the three-phase AC synchronous motor, it is possible to avoid the resonance point that depends on the rotation speed of the rotor 6.

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

In addition, the center of the weight reduction hole 11 is located at a position that overlaps with the d-axis or q-axis, and is located at a position that does not interfere with the magnet insertion hole 10 into which the permanent magnet 9 is inserted. If the center of the weight reduction hole 11 is not located on the d-axis or q-axis, the distribution of the interlinkage magnetic flux becomes asymmetric with respect to the d-axis and q-axis, and the spatial harmonic components of the magnetic flux increase. This increases iron loss, radial electromagnetic force, and torque ripple. To prevent this, the center of the weight reduction hole 11 is located at a position that overlaps with the d-axis or q-axis.

In this way, according to the first embodiment, the rotor core 8 is provided with the weight-reducing holes 11, which are through holes, the mass body 17 is arranged so as to penetrate the rotor core 8, protrusions 18 are provided at both ends of the mass body 17 as first guide bodies, and the end plate 16 is provided with guide holes 19 as second guide bodies, and the sliding of the protrusions 18 relative to the guide holes 19 guides the oscillation of the mass body 17 relative to the rotor core 8. This makes it possible to suppress vibrations and noise due to torque ripple without increasing the volume of the rotor 6.

Embodiment 2.
Fig. 9 is a plan view showing the configuration of rotor core 8 of a rotating electric machine according to embodiment 2. Fig. 10 is a perspective view showing the configuration of an end plate 32 of a rotating electric machine according to embodiment 2. In embodiment 2, mass body 17 of embodiment 1 is replaced with mass body 30, and end plate 16 of embodiment 1 is replaced with end plate 32. Other configurations in embodiment 2 are similar to those in embodiment 1, and repeated explanations will be omitted.

In embodiment 2, as shown in FIG. 9, guide grooves 31, which are recesses that define the swing trajectory, are provided at both ends of each mass body 30. The guide grooves 31 correspond to the first guide body. Also, as shown in FIG. 10, a plurality of protrusions 33, which are convex portions, are provided intermittently in the circumferential direction on each end plate 32. The protrusions 33 correspond to the second guide body. In embodiment 2, one protrusion 33 is provided corresponding to each guide groove 31, and each protrusion 33 slides within each guide groove 31.

In this configuration, the mass body 30 slides and at the same time rotates around the axis of the protrusion 33. The axial center of the protrusion 33 is eccentric and offset from the center of gravity (center) of the mass body 30. If the guide groove 31 is provided radially outward from the center position of the mass body 30, there is a possibility that the mass body 30 will collide with the inner wall of the weight reduction hole 11 when it rotates around its axis. To prevent this, according to embodiment 2, the guide groove 31 is provided radially inward from the center position of the mass body 30.

According to the second embodiment, 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 reduction hole 11 due to rotation of the mass body 30 can be prevented.

Embodiment 3.
Fig. 11 is a perspective view showing a configuration of a pendulum mass body 41 of a rotating electric machine according to the third embodiment. Fig. 12 is a perspective view showing a configuration of an end plate 46 of a rotating electric machine according to the third embodiment. As shown in Fig. 11, the pendulum mass body 41 includes a first mass body 41a including a weight portion 43a having projections 42a as first projections at both ends, a second mass body 41b including a weight portion 43b having projections 42b as second projections at both ends, and a connecting member 45 connecting the

projections

42a and 42b. The first mass body 41a is inserted into the weight reduction hole 11 as a first through hole, and the second mass body 41b is inserted into the weight reduction hole 11 as a second through hole.

As shown in FIG. 12, the end plate 46 is formed with two guide holes 47, which are through holes that guide the two

protrusions

42a and 42b of the pendulum mass body 41, and a recess 48 that connects the two guide holes 47 and serves as a third recess that accommodates the connecting member 45 of the pendulum mass body 41. One of the two guide holes 47 corresponds to the first recess, and the other corresponds to the second recess. The end plate 46 is provided with four sets of configurations having two guide holes 47 and recesses 48 in order to support the four pendulum mass bodies 41. The other configurations in the third embodiment are the same as those in the first embodiment, and redundant explanations will be omitted. Note that three or more weights may be connected to the pendulum mass body 41. Although the lightening hole 11 in the third embodiment is not shown, it is preferable that the lightening hole 11 has a shape similar to the cross-sectional shape of the

weights

43a and 43b, as in the lightening hole 11 in the first embodiment.

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. The connecting member 45 has the effect of preventing the mass 41 from rotating around the

protrusions

42a and 42b. Furthermore, as shown in Figures 4 and 8, if two guide holes 19 can be arranged corresponding to one weight reduction hole 11, the mass 41 can be prevented from rotating. However, even if only one guide hole 19 can be arranged corresponding to one weight reduction hole 11, this configuration can prevent the mass 41 from rotating and promote the sliding of the mass 41.

In addition, the recess 48 is provided in the end plate 46, so that the connecting member 45 can be prevented from being exposed. The pair of guide holes 47 are arranged in mirror symmetry with respect to a radial line that passes through the middle of the pair of guide holes 47. This allows the mass body 41 to perform pendulum motion with the positional relationship of the axes of the two

protrusions

42a, 42b fixed.

According to the third embodiment, the pendulum mass 41 is formed by connecting the first mass 41a and the second mass 41b with the connecting member 45, which prevents the mass 41 from rotating and promotes the sliding of the mass 41.

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, which faces 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, one end plate 32 of the rotating electric machine of the second embodiment is replaced with an end plate 51, and the other end plate 32 of the rotating electric machine of the second embodiment is replaced with an end plate 56. The other configurations in the fourth embodiment are the same as those in the second embodiment, and redundant explanations 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 a plurality of mass bodies 30 having a plurality of weight-reducing holes 11 and guide grooves 31 shown in FIG. 9 are provided in the rotor core 8 shown in FIG. In this way, the protrusions 52 in the fourth embodiment correspond to the protrusions 33 in the second embodiment.

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

As shown in FIG. 14, a flow path 53 is formed on the back surface of the end plate 51 as an oil groove. The flow path 53 reduces the contact friction of the protrusions 52 engaging with the guide grooves 31, and allows the flow of lubricating oil that cools the rotor core 8 as a whole. The flow path 53 has a plurality of grooves 53a extending from the shaft hole 20 on the inner periphery side of the end plate 51 to the protrusions 52, and a plurality of grooves 53b branching from the protrusions 52 and extending to the outer periphery of the end plate 51. The ends of the plurality of grooves 53b are provided at positions corresponding to the inter-pole gaps 14 formed in the rotor core 8. The lubricating oil that flows in from the shaft hole 20 flows into the protrusions 52 and guide grooves 31 via the plurality of grooves 53a, as shown by the arrows in FIG. 16, and a portion of the lubricating oil flows into the inside of the weight reduction hole 11 of the rotor core 8 into which the mass body 30 is inserted. The remaining lubricating oil flows through groove 53b while branching, as shown by the arrows in Figure 16, and reaches tip 55 of groove 53b, and then flows into inter-pole gap 14 of rotor core 8.

As shown in Figures 13 and 15, the end plate 56 has a plurality of discharge holes 57 provided at positions corresponding to the plurality of weight reduction holes 11 of the rotor core 8, and a plurality of discharge holes 58 provided at positions corresponding to the plurality of inter-pole gaps 14 of the rotor core 8. The lubricating oil that flows into the weight reduction holes 11 of the rotor core 8 from the end plate 51 on one side is discharged from the discharge holes 57 of the end plate 56. In addition, the lubricating oil that flows into the inter-pole gaps 14 of the rotor core 8 from the end plate 51 on one side is discharged from the discharge holes 58 of the end plate 56.

As the rotor core 8 rotates, the lubricating oil inside the weight reduction hole 11 is subjected to centrifugal force and flows out from the radially outer inner wall. Therefore, for efficient discharge, it is desirable to position the discharge hole 57 radially outward of the weight reduction hole 11. In the above configuration, the lubricating oil is discharged radially outward of the rotor core 8, but the flow path configuration may also be such that the lubricating oil is recovered toward the shaft hole 20.

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

The configurations shown in the above embodiments are merely examples of the contents of this disclosure, and may be combined with other known technologies. Parts of the configurations may be omitted or modified without departing from the spirit of this disclosure.

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 weight reduction 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 part, 31 guide groove, 41a first mass, 41b second mass, 45 connecting member, 48 recess, 53 flow path, 53a, 53b groove, 55 tip, 57, 58 discharge hole.

Claims

A rotor and a stator are provided.
The rotor is
A rotor core having a shaft hole;
A plurality of permanent magnets provided on an 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 protrusions and the recesses;
a first guide body sliding relative to a second guide body to guide a swinging movement of the mass body relative to the rotor core,
If the number of pole pairs of the permanent magnet is N, the rotation radius L of the swing orbit of the mass body and the distance R between the rotation center of the swing orbit of the mass body and the center of the rotor core are set according to the following formula: R/L = (6N) 2
2. The rotating electric machine according to claim 1 .
3 . The rotating electric machine according to claim 1 , wherein the end plate is provided with an oil groove for allowing lubricating oil to flow in the first guide body of the mass body and the second guide body of the end plate. 4 .
The rotating electric machine according to claim 1 , wherein the center of the through hole is located at a position overlapping with a d-axis or a q-axis.
the mass body includes a first mass body that is inserted into the first through hole and has first convex portions at both ends, a second mass body that is inserted into the second through hole and has second convex portions at both ends, and a connecting member that connects the first convex portion and the second convex portion,
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,
5. The rotating electric machine according to claim 1, wherein the first recess and the second recess are arranged in mirror symmetry with respect to a radial line passing through centers of the first recess and the second recess.
The rotating electric machine according to claim 5 , wherein the pair of end plates each include a third recess that connects the first recess and the second recess and receives the connecting member.
Each of the first guide bodies and each of the second guide bodies have one convex portion or one concave portion,
5. 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.
Each of the first guide bodies and each of the second guide bodies have two protrusions or two recesses,
The rotating electric machine according to claim 1 , wherein the two recesses are arranged in mirror symmetry with respect to a radial line passing through centers of the two recesses.
9. The rotating electric machine according to claim 1, wherein an overall length of the mass body is equal to or less than a combined length of an axial length of the rotor core and a thickness of the pair of end plates.