JP2019017187A - Rotary electric machine, in-wheel motor drive device including the same, and manufacturing method of rotary electric machine - Google Patents

Abstract

To provide a rotary electric machine which enables reduction of vibration caused by deformation of a stator and enables an axis of the stator and a rotation axis to be matched, and to provide an in-wheel motor drive device including the rotary electric machine and a manufacturing method of the rotary electric machine.SOLUTION: A rotary electric machine includes: a motor housing 8; an annular stator 9 provided at an inner periphery of the motor housing 8; a rotary shaft 6 which is rotatably supported through bearings 11, 12 on the motor housing 8; and a rotor 10 which is located at the radial inner side of the stator 9 and integrally disposed with the rotary shaft 6. An elastic member 20 is disposed between an outer peripheral surface of the stator 9 and an inner periphery surface of the motor housing 8 over an entire periphery. A surface of the elastic member 20 which contacts with the outer peripheral surface of the stator 9 is a refined surface. The elastic member 20 is formed by a high polymer material, and a linear expansion coefficient of the high polymer material is larger than a linear expansion coefficient of the motor housing 8.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a rotary motor, an in-wheel motor drive device including the rotary motor, and a method for manufacturing the rotary motor, and reduces vibration caused by a stator that is a component of the rotary motor, and also includes a stator axis and a rotary shaft. It relates to technology that can match the mind.

  Rotating motors are widely used in vehicles, industrial machines, and the like, and are required to be small, light, high efficiency, high output, and low vibration (low noise). The rotating motor is energized through a coil wound around the stator and switches energization to each phase, so that the rotational torque is generated by the interaction between the magnetic force generated from the coil and the magnetic force from the permanent magnet fixed to the rotor. Occur. At this time, since a reaction force in the radial direction acts on the stator core, the stator is deformed in the radial direction at a cycle corresponding to the rotational speed of the rotor. As a result, vibration due to the deformation of the stator occurs.

The following structure has been proposed as a method of suppressing vibration generated from the stator in a rotary electric motor.
(1). A ring for fixing the stator to the housing is provided on the outer peripheral portion of the stator core, and the ring has a bent portion that is elastically deformed when the stator is displaced (Patent Document 1). A structure in which the bent portion can reduce the vibration by absorbing the vibration of the stator.

(2). A structure that reduces a vibration generated from the stator by providing a groove in the outer peripheral part of the stator core or the inner diameter part of the housing, fitting an elastic member having elasticity or viscoelasticity into the groove, and holding the stator in a floating state ( Patent Document 2).

(3). A first portion having a housing having an opening for storing the stator, wherein a gap between the inner peripheral surface of the opening of the housing and the stator core is relatively small, and an inner diameter of the opening is constant; and an axial direction of the stator core And a second portion having a relatively large gap between the inner peripheral surface of the opening and the stator core (Patent Documents 3 and 4). With this structure, the contact area between the stator core and the housing is reduced, and as a result, vibrations generated from the stator are reduced.

JP 2010-124661 A JP 2007-189812 A JP 2007-228725 A Japanese Patent No. 4774780

  In Patent Document 1, it is proposed to suppress vibration by installing a ring provided with a bent portion that is elastically deformed between the stator core and the housing, but the shape of the bent portion is complicated and difficult to process. . There are two main methods of fixing the ring with the stator fixed to the housing. The first method is to fix the ring to the housing in a floating manner. In this method, it is difficult to make the center of the stator coincide with the center of rotation. The cogging torque increases due to the deviation between the center of the stator and the center of rotation. The second method is to make the center of the stator coincide with the center of rotation by bringing the ring into contact with the housing, but in this method, the stator is not considered to be completely floating with respect to the housing. It is difficult to completely prevent the vibration of the stator.

  Patent Document 2 proposes floating holding of the stator core and the housing via an elastic body (resin or rubber), but does not mention a method for matching the center of the stator and the center of the rotating body.

  Patent Document 3 proposes a structure that reduces vibration transmission due to stator deformation by reducing the contact area between the stator core and the housing. However, since there is a contact portion, vibration due to the stator is completely eliminated. It is difficult.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary electric motor capable of reducing vibration caused by deformation of the stator and aligning the axis of the stator with the rotary axis, an in-wheel motor drive apparatus and a rotary electric motor provided with the rotary motor. It is to provide a manufacturing method.

A rotary motor according to the present invention includes a housing, an annular stator provided on the inner periphery of the housing, a rotating shaft that is rotatably supported by the housing via a bearing, and a radially inner position of the stator. In a rotary electric motor comprising a rotor arranged integrally with the rotary shaft,
Between the outer peripheral surface of the stator and the inner peripheral surface of the housing, an elastic member is interposed continuously or discontinuously in the circumferential direction, and the surface of the elastic member is in contact with the outer peripheral surface of the stator. Is the refined surface.
The surface of the elastic member that is in contact with the outer peripheral surface of the stator is finer than the surface roughness of the other surface of the elastic member, and the surface of the elastic member that is in contact with the outer peripheral surface of the stator. The dimensional accuracy is higher than the dimensional accuracy of the other surface of the elastic member.

In the rotary electric motor, the rotor rotates due to the interaction of magnetic forces, but at the same time, a reaction force in the radial direction acts on the stator, so that vibrations due to deformation of the stator occur.
According to this configuration, the outer peripheral surface of the stator is supported in contact with the refined surface of the elastic member, so that the entire stator can be supported in a floating manner with respect to the housing. As a result, the elastic member dampens or absorbs vibration caused by the deformation of the stator. For this reason, it can suppress that the vibration resulting from a deformation | transformation of a stator is transmitted to a housing. Further, since the outer peripheral surface of the stator is supported by being brought into contact with the refined surface of the elastic member, it is possible to match the stator shaft center with the rotation shaft center. Cogging torque caused by the deviation can be reduced.

Preferably, the elastic member is made of a polymer material, and the linear expansion coefficient of the polymer material is larger than the linear expansion coefficient of the housing.
The term “greater than the linear expansion coefficient of the housing” includes a linear expansion coefficient that is preferably about 2 to 7 times the linear expansion coefficient of the housing.
In this case, even if the stator is thermally expanded due to a temperature rise, the housing is also thermally expanded following the stator, so that the stator is permanently and stably supported by the housing regardless of the temperature change of the rotary motor. Can do.

  A groove for accommodating the outer peripheral portion of the elastic member may be formed on the inner peripheral surface of the housing. In this case, the elastic member can be easily positioned with respect to the housing, and thus the manufacturing cost can be reduced.

  The radial thickness of the elastic member may be in the range of 5% to 80% of the radial thickness of the housing. In this case, the rigidity of the housing is not affected, and vibration due to the deformation of the stator can be prevented from being transmitted to the housing.

  The stator may include a stator core and a stator coil wound around the stator core, and the elastic member may be provided within an axial range of the stator core. In this case, the elastic member can reliably suppress or absorb the vibration caused by the deformation of the stator.

  A reduction gear that decelerates and outputs the rotation of the rotation shaft may be provided in the housing. Even in such a rotary electric motor with a reduction gear, it is possible to reduce the vibration caused by the deformation of the stator and to make the rotary electric motor excellent in silence.

  The in-wheel motor drive device of this invention is equipped with the wheel bearing which supports a wheel, and the rotary motor in any one of the said which rotates the rotating wheel of this wheel bearing. In a vehicle equipped with an in-wheel motor drive device, it may be difficult to reduce vibrations generated by the rotary motor as compared to an on-board type vehicle in which the rotary motor is mounted on the vehicle body. In this configuration, the in-wheel motor drive apparatus includes any one of the rotary electric motors described above, so that vibrations caused by the deformation of the stator can be suppressed from being transmitted to the housing. Further, since the outer peripheral surface of the stator is supported by being brought into contact with the refined surface of the elastic member, it becomes possible to make the axis of the stator and the rotation axis coincide with each other. The cogging torque resulting from the deviation can be reduced.

A method of manufacturing a rotary motor according to the present invention includes a housing, an annular stator provided on the inner periphery of the housing, a rotating shaft that is rotatably supported by the housing via a bearing, and an inner radial direction of the stator. A manufacturing method for manufacturing a rotary electric motor including a rotor that is located on a side and is disposed integrally with the rotary shaft,
An elastic member installation process in which an elastic member is provided on the inner peripheral surface of the housing continuously or discontinuously in the circumferential direction over the entire circumference;
After this elastic member installation process, a refinement process in which the surface to be in contact with the outer peripheral surface of the stator in the elastic member is made into a refined surface by machining coaxially with the rotation center of the rotating shaft,
After this refinement process, the stator support process of contacting the outer peripheral surface of the stator with the refinement surface of the elastic member and supporting the stator to the housing.
The refined surface has a surface roughness of the elastic member that should be in contact with the outer peripheral surface of the stator, finer than the surface roughness of the other surface of the elastic member, and is in contact with the outer peripheral surface of the stator of the elastic member. The dimension of the power surface is more accurate than the dimension of the other surface of the elastic member.

  According to this configuration, in the elastic member installation process, the elastic member is provided on the inner peripheral surface of the housing over the entire circumference or discontinuously in the circumferential direction. Thereafter, in the refinement process, the surface of the elastic member that should contact the outer peripheral surface of the stator is defined as the refinement surface. Thereafter, in the stator support process, the outer peripheral surface of the stator is brought into contact with the refined surface of the elastic member, and the stator is supported by the housing.

  In particular, since the outer peripheral surface of the stator is brought into contact with the refined surface of the elastic member and the stator is supported by the housing, the stator can be supported in a floating manner with respect to the housing. As a result, the elastic member dampens or absorbs vibration caused by the deformation of the stator. For this reason, it can suppress that the vibration resulting from a deformation | transformation of a stator is transmitted to a housing. In addition, in the refinement process, the surface of the elastic member that should be in contact with the outer peripheral surface of the stator is used as the refinement surface, so that the stator axis and the rotation axis can be aligned. The cogging torque resulting from the deviation from the heart can be reduced.

  The elastic member installation process includes a process of casting the elastic member into a groove formed on the inner peripheral surface of the housing, and the refinement process includes a process of casting the elastic member into the groove of the housing. A process of machining the inner peripheral surface coaxially with the rotation center of the rotation shaft may be included. In this case, the inner peripheral surface of the elastic member cast and formed in the groove of the housing can be made into a refined surface reliably and at low cost.

  A rotary motor according to the present invention includes a housing, an annular stator provided on the inner periphery of the housing, a rotating shaft that is rotatably supported by the housing via a bearing, and a radially inner position of the stator. Then, in the rotary electric motor including the rotor disposed integrally with the rotation shaft, the entire circumference is continuously or discontinuously between the outer peripheral surface of the stator and the inner peripheral surface of the housing. An elastic member is interposed in the surface, and the surface of the elastic member that contacts the outer peripheral surface of the stator is a refined surface. For this reason, the vibration resulting from a deformation | transformation of a stator can be reduced, and the axial center of a stator and a rotating shaft center can be corresponded.

  Since the in-wheel motor drive device of this invention is equipped with the wheel bearing which supports a wheel, and the rotation motor in any one of the above which rotates the rotation wheel of this wheel bearing, it is an in-wheel motor form. However, the vibration caused by the deformation of the stator can be reduced, and the axis of the stator can coincide with the rotation axis.

  A method of manufacturing a rotary motor according to the present invention includes a housing, an annular stator provided on the inner periphery of the housing, a rotating shaft that is rotatably supported by the housing via a bearing, and an inner radial direction of the stator. And a rotor disposed integrally with the rotating shaft, the manufacturing method for manufacturing the rotating motor on the inner peripheral surface of the housing continuously or circumferentially. The elastic member installation process in which the elastic member is continuously provided, and after the elastic member installation process, the surface of the elastic member that should be in contact with the outer peripheral surface of the stator is machined coaxially with the rotation center of the rotating shaft. A refinement process for making a precision surface, and after this refinement process, the stator is supported on the housing by contacting the outer peripheral surface of the stator with the refinement surface of the elastic member. Has a lifting process, the. For this reason, the vibration resulting from a deformation | transformation of a stator can be reduced, and the axial center of a stator and a rotating shaft center can be corresponded.

It is sectional drawing of the in-wheel motor drive device provided with the rotary electric motor which concerns on embodiment of this invention. It is sectional drawing of the motor part used as the II-II line cross section of FIG. It is an expanded sectional view of the principal part of the rotary electric motor. It is a flowchart which shows the manufacturing method of the rotary electric motor in steps. It is sectional drawing of the in-wheel motor drive device provided with the rotary electric motor which concerns on other embodiment of this invention. It is sectional drawing of the reduction gear part used as the VI-VI line cross section of FIG. It is the elements on larger scale of FIG. It is sectional drawing of the rotary electric motor which concerns on other embodiment of this invention. It is a figure which shows schematic structure of the vehicle carrying any one rotary electric motor.

An embodiment of the present invention will be described with reference to FIGS.
<Overall configuration of in-wheel motor drive device>
FIG. 1 is a cross-sectional view of an in-wheel motor drive device provided with a rotary motor according to this embodiment.
The vehicle is, for example, an in-wheel motor type in which two in-wheel motor driving devices are mounted and left and right driving wheels are independently driven by these in-wheel motor driving devices. Since the two in-wheel motor driving devices have the same configuration, only one in-wheel motor driving device is shown in FIG.

  This in-wheel motor drive device includes a rotary electric motor 1 that generates a driving force of a vehicle, a speed reducer 2 that decelerates and outputs the rotation of the rotary electric motor 1, and an output from the speed reducer 2 that is not shown. And a wheel hub bearing portion (wheel bearing) 5 for transmitting to the wheel. The rotary motor 1, the speed reducer 2, and the wheel bearing 5 constitute an in-wheel motor drive device that is one assembly part, and the in-wheel motor drive device is partially or entirely disposed in the wheel. The In this specification, the side closer to the outer side in the vehicle width direction of the vehicle with the in-wheel motor drive device provided in the vehicle is referred to as the outboard side, and the side closer to the center in the vehicle width direction of the vehicle is referred to as the inboard. Call the side.

<Rotary motor 1>
In the rotary motor, the rotor rotates due to the interaction of magnetic forces, but at the same time, a reaction force in the radial direction acts on the stator, so that vibration due to deformation of the stator occurs. It is a problem to ensure a method for making this shaft axis coincide with the rotation axis without transmitting this vibration to the outside, for example, a housing made of aluminum.

  The rotary electric motor 1 includes a motor housing 8, an annular stator 9, a rotating shaft 6, and a rotor 10. The rotary electric motor 1 includes an interior permanent magnet (Interior Permanent Magnet) in which a radial gap is provided between a stator 9 provided on the inner periphery of a motor housing 8 and a rotor 10 positioned radially inward of the stator 9. Motor: Abbreviation: IPM motor). The motor housing 8 is provided with bearings 11 and 12 which are separated from each other in the axial direction, and the rotary shaft 6 is rotatable in the bearings 11 and 12. The rotor 10 is disposed integrally with the bearings 11 and 12.

  The rotating shaft 6 transmits the driving force of the rotary electric motor 1 to the speed reducer 2. A flange portion 6 a extending radially outward is provided in the vicinity of the middle portion of the rotation shaft 6 in the axial direction. A rotor fixing member 13 is provided on the flange portion 6 a, and the rotor 10 is attached to the rotor fixing member 13. The rotor 10 includes, for example, a core portion (not shown) made of a soft magnetic material and a permanent magnet (not shown) built in the core portion. For example, a neodymium magnet is used as the permanent magnet.

  The stator 9 includes, for example, a stator core 9a made of a soft magnetic material, and a stator coil 9b wound around the stator core 9a. The stator core 9a has a ring shape with an outer peripheral surface having a circular cross section, and a plurality of teeth protruding inward on the inner peripheral surface are formed side by side in the circumferential direction. The stator coil 9b is wound around the teeth of the stator core 9a. The outer peripheral surface of the stator 9 is fitted to the inner peripheral surface of the motor housing 8 via an elastic member 20 to be described later, and is fastened and fixed in the axial direction by a plurality of bolts 23. As shown in FIG. 2, the plurality of bolts 23 are provided at regular intervals in the circumferential direction.

  As shown in FIG. 3, an annular housing step portion 8a is provided in the motor housing 8 so as to face the outer diameter side portion of the axial end surface of the stator core 9a. A plurality of internal threads are formed in the housing step 8a at regular intervals in the circumferential direction. The stator 9 is fixed by bringing the axial end surface of the stator core 9a on the outboard side into contact with the housing step portion 8a and screwing it into each female screw through the plurality of bolts 23 (FIG. 1) from the inboard side of the stator core 9a. ing.

  As shown in FIGS. 2 and 3, an elastic member 20 is interposed over the entire circumference between the outer peripheral surface of the stator core 9 a and the inner peripheral surface of the motor housing 8. Grooves 8b are formed in the circumferential direction on the inner peripheral surface of the motor housing 8 facing the outer peripheral surface of the stator core 9a. The groove 8b is an annular groove finished by machining such as turning. Of the inner peripheral surface of the motor housing 8 that faces the outer peripheral surface of the stator core 9a, the portions other than the groove portions, for example, remain the cast surface and the like, and finishing by machining is not particularly required.

  The outer peripheral portion of the annular elastic member 20 is accommodated in the groove 8 b finished by machining on the inner peripheral surface of the motor housing 8. The elastic member 20 is made of a polymer material having a linear expansion coefficient larger than that of the motor housing 8 and can be machined such as turning. The linear expansion coefficient of the polymer material is larger than the linear expansion coefficient of the motor housing 8. A linear expansion coefficient of preferably about 2 to 7 times is also included. The motor housing 8 is made of, for example, an aluminum material. For example, polyamide 9T, polyamide 11, polyamide 66, or the like is applied to the elastic member 20 as a polymer material having a linear expansion coefficient larger than that of an aluminum material. The linear expansion coefficient is more preferably about 2 to 7 times.

  An elastic member 20 is cast in a groove 8b formed on the inner peripheral surface of the motor housing 8, and the elastic member 20 is provided in the axial range L1 of the stator core 9a. In addition, the axial intermediate portion of the elastic member 20 is disposed in the axial intermediate portion of the stator core 9a. The radial thickness t1 of the elastic member 20 is in the range of 5% to 80% of the radial thickness t2 of the motor housing 8. However, the inner peripheral surface 20 a of the elastic member 20 (the surface in contact with the outer peripheral surface of the stator core 9 a) protrudes a predetermined distance radially inward from the portion other than the groove portion of the inner peripheral surface of the motor housing 8.

  The surface of the elastic member 20 that contacts the outer peripheral surface of the stator core 9a is a refined surface. In the refined surface, the dimensional accuracy of the inner peripheral surface 20 a of the elastic member 20 is higher than the dimensional accuracy of the outer peripheral surface of the elastic member 20. The high dimensional accuracy of the inner peripheral surface 20a of the elastic member 20 means that the inner peripheral surface 20a of the elastic member 20 is more than the outer peripheral surface of the elastic member 20 with respect to the coaxiality of the bearings 11 and 12. The coaxiality is good.

The inner peripheral surface 20a of the elastic member 20 cast into the groove 8b of the motor housing 8 is finished by machining such as turning or grinding so as to be coaxial with the rotation center Lc of the rotating shaft 6. A chemical surface is formed. When the coaxiality between the inner peripheral surface 20a of the elastic member 20 and the portions supporting the bearings 11 and 12 is, for example, 0.05 mm or less, the inner peripheral surface 20a of the elastic member 20 and the rotation center Lc of the rotating shaft 6 are obtained. And are determined to be coaxial. The locations where the bearings 11 and 12 are supported are the outer ring fitting surfaces 8 ₁₁ and 8 ₁₂ of the bearings 11 and 12 in the motor housing 8 and the inner ring fitting surfaces 6 ₁₁ and 6 of the bearings 11 and 12 on the rotary shaft 6. ₁₂ .

  As shown in FIG. 1, the rotary shaft 6 is located at the center of the rotary electric motor 1. A part of the rotation shaft 6 in the axial direction protrudes into the reduction gear 2 on the outboard side, and is splined (including serrations, the same applies hereinafter) to the input gear shaft 32 of the reduction gear 2 coaxially. The rotary electric motor 1 is provided with a rotational speed detection means Sa such as a resolver that detects the rotational speed of the rotary shaft 6.

<Reduction gears, etc.>
The speed reducer 2 is a parallel shaft gear reduction comprising an input gear shaft 32 having an input gear 32a, an intermediate gear shaft 33 having first and second intermediate gears 33a and 33b, and an output gear shaft 34 having an output gear 34a. Machine. The input gear shaft 32 is rotatably supported via rolling bearings 35 and 35 provided in the motor housing 8. The intermediate gear shaft 33 is a stepped gear having a large-diameter first intermediate gear 33a meshing with the input gear 32a and a small-diameter second intermediate gear 33b meshing with the output gear 34a on the outer peripheral surface. The intermediate gear shaft 33 is rotatably supported via rolling bearings 36 and 37 provided in the motor housing 8. The output gear shaft 34 has a large-diameter output gear 34 a and is rotatably supported via rolling bearings 39 and 40 provided in the motor housing 8.

  The input gear shaft 32 is transmitted with driving force from the rotating shaft 6 of the rotary electric motor 1. The first intermediate gear 33a meshes with the input gear 32a, and the second intermediate gear 33b meshes with the output gear 34a. A part of the output gear shaft 34 in the axial direction is pulled out from the motor housing 8 to the outboard side, and is spline-fitted to the rotating wheel of the wheel hub bearing portion 5 to transmit a driving force to a driving wheel (not shown).

<About the manufacturing method of the rotary motor 1>
FIG. 6 is a flowchart showing the manufacturing method of this rotary motor step by step. 1 and 3 will be described as appropriate. The method for manufacturing the rotary motor 1 includes an elastic member installation process S1, a refinement process S2, and a stator support process S3. In the elastic member installation process S <b> 1, the elastic member 20 is cast and formed in the groove 8 b finished by machining on the inner peripheral surface of the motor housing 8. Thus, the elastic member 20 is installed on the inner peripheral surface of the motor housing 8 over the entire circumference. The cast molding is also referred to as “cast molding” in which a flowable polymer material is poured into a mold (not shown) to perform desired molding.

  After the elastic member installation process S1, in the refinement process S2, the inner peripheral surface 20a of the elastic member 20 is used as the refinement surface. As described above, the inner circumferential surface 20a of the elastic member 20 cast into the groove 8b is finished coaxially with the rotation center Lc of the rotating shaft 6 by machining such as turning or grinding, A refined surface is formed. After the refinement process S2, in the stator support process S3, the outer peripheral surface of the stator 9 is brought into contact with the refined surface of the elastic member 20. Further, the axial end surface of the stator core 9a on the outboard side is brought into contact with the housing step portion 8a, and the stator 9 is screwed into the respective female screws through the plurality of bolts 23 from the inboard side of the stator core 9a. To support.

<Effect>
In the rotary electric motor 1, the rotor 10 rotates due to the interaction of magnetic forces, but at the same time, a reaction force in the radial direction acts on the stator 9, so that vibration due to deformation of the stator 9 occurs.
According to the rotary electric motor 1 and the manufacturing method thereof described above, the outer peripheral surface of the stator 9 is supported by being brought into contact with the refined surface of the elastic member 20, so that the entire stator is uniformly supported by the motor housing 8. can do. Thereby, the elastic member 20 dampens or absorbs the vibration caused by the deformation of the stator 9.

  For this reason, it can suppress that the vibration resulting from a deformation | transformation of the stator 9 is transmitted to the motor housing 8. FIG. Further, since the outer peripheral surface of the stator 9 is supported by being brought into contact with the refined surface of the elastic member 20, it is possible to make the axis of the stator 9 coincide with the rotation axis. The cogging torque resulting from the deviation from the heart can be reduced. Therefore, it can be set as the rotary electric motor 1 excellent in silence. Of the inner peripheral surface of the motor housing 8 that faces the outer peripheral surface of the stator core 9a, the part other than the groove remains, for example, a cast surface and the like, and no machining finish is required. And processing costs can be reduced.

Since the linear expansion coefficient of the elastic member 20 is larger than the linear expansion coefficient of the motor housing 8, even if the stator 9 is thermally expanded due to a temperature rise, the motor housing 8 is also thermally expanded following the stator 9. Thus, the stator 9 can be permanently and stably supported by the motor housing 8 regardless of the temperature change of the rotary electric motor 1.
Since the groove 8b in which the outer peripheral portion of the elastic member 20 is accommodated is formed on the inner peripheral surface of the motor housing 8, the elastic member 20 can be easily positioned with respect to the motor housing 8, thereby reducing the manufacturing cost. Can be achieved.

Since the radial thickness t1 of the elastic member 20 is in the range of 5% to 80% of the radial thickness t2 of the motor housing 8, the rigidity of the motor housing 8 is not affected, and the stator 9 is deformed. The vibration due to can be prevented from being transmitted to the motor housing 8.
Since the elastic member 20 is provided in the axial range L1 of the stator core 9a, vibration due to deformation of the stator 9 can be reliably suppressed or absorbed by the elastic member 20.

<About other embodiments>
In the following description, the same reference numerals are given to portions corresponding to the matters described in advance in the respective embodiments, and overlapping descriptions are omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in advance unless otherwise specified. The same effect is obtained from the same configuration. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

As shown in FIGS. 5 to 7, the speed reducer 2 may be a cycloid speed reducer.
The in-wheel motor drive device shown in FIG. 5 includes a rotary motor 1 that drives a wheel, a speed reducer 2 that decelerates the rotation of the rotary motor 1, and an input shaft 3 (referred to as a speed reducer input shaft 3) of the speed reducer 2. ) And a wheel bearing 5 rotated by a coaxial output member 4.

A reduction gear 2 is interposed between the wheel bearing 5 and the rotary motor 1, and a wheel hub (not shown) that is a drive wheel supported by the wheel bearing 5, the rotary shaft 6 of the rotary motor 1, and the reduction gear. The input shaft 3 and the output member 4 are connected on the same axis.
A suspension (not shown) in the vehicle is connected to the reduction gear housing 7 that houses the reduction gear 2.

<About reducers>
As shown in FIG. 5, the speed reducer input shaft 3 has one end in the axial direction extending into the rotating shaft 6 and is spline-fitted with the rotating shaft 6. A bearing 14 a is fitted in the cup portion 4 a of the output member 4, and a bearing 14 b is fitted in a cylindrical connecting member 26 that is connected to the cup portion 4 a via an inner pin 22. The integral shaft of the speed reducer input shaft 3 and the rotating shaft 6 is rotatably supported by bearings 14a, 14b, 11, and 12. Eccentric portions 15 and 16 are provided on the outer peripheral surface of the speed reducer input shaft 3 in the speed reducer housing 7. These eccentric portions 15 and 16 are provided with a 180 ° phase shift so that the centrifugal force due to the eccentric motion is canceled out from each other.

The reducer 2 is a cycloid reducer having an outer pin housing Ih, a reducer input shaft 3, curved plates 17 and 18, a plurality of outer pins 19, inner pins 22, and a counterweight 21.
As shown in FIG. 6, the speed reducer 2 has two curved plates 17 and 18 formed with wavy trochoidal curves having a gentle outer shape, mounted on the eccentric parts 15 and 16 via bearings 85, respectively. It is. A plurality of outer pins 19 for guiding the eccentric movements of the curved plates 17 and 18 on the outer peripheral side are respectively provided on the outer pin housing Ih (FIG. 5) inside the reduction gear housing 7, and attached to the cup portion 4a (FIG. 5). The plurality of inner pins 22 are engaged with a plurality of circular through holes 89 provided in the curved plates 17 and 18 in an inserted state.

  As shown in an enlarged view in FIG. 7, needle roller bearings 92 and 93 are attached to each outer pin 19 and each inner pin 22. Each outer pin 19 is supported at both ends by needle roller bearings 92 and is in rolling contact with the outer peripheral surface of each curved plate 17, 18. Each inner pin 22 is in contact with the inner periphery of each through-hole 89 by the outer ring 93 a of the needle roller bearing 93. Needle roller bearings 92 and 93 reduce the contact resistance between the curved plates 17 and 18 and the contact resistance between the inner pins 22 and the through holes 89, respectively. The outer ring 93a of the needle roller bearing 92 is fitted and fixed to the outer pin housing Ih.

  Therefore, as shown in FIG. 5, the eccentric motion of each of the curved plates 17 and 18 can be smoothly transmitted as a rotational motion to the inner member 5 a of the wheel bearing 5. When the rotary shaft 6 rotates, the curved plates 17 and 18 provided on the outer circumferences of the eccentric portions 15 and 16 of the speed reducer input shaft 3 rotating integrally with the rotary shaft 6 perform an eccentric motion. At this time, the outer pin 19 is engaged so as to be in rolling contact with the outer peripheral surfaces of the curved plates 17 and 18 that are eccentrically moved. At the same time, the curved plates 17 and 18 are engaged with the inner pins 22 and the through-holes 89 (FIG. 7), so that only the rotational movement of the curved plates 17 and 18 is rotationally moved to the output member 4 and the inner member 5a. As transmitted. The rotation of the inner member 5a is decelerated with respect to the rotation of the rotating shaft 6.

<About Lubricating Oil Supply Mechanism Jk>
This in-wheel motor drive device has a lubricating oil supply mechanism Jk. The lubricating oil supply mechanism Jk is an axial oil supply mechanism that supplies lubricating oil used for both the lubrication of the speed reducer 2 and the cooling of the rotary electric motor 1 from the inside of the rotating shaft 6. The lubricating oil supply mechanism Jk includes a lubricating oil passage 29, a supply oil passage 30, an in-motor lubricating oil reservoir 31, a discharge oil passage 38, and a pump 28. The lubricating oil passage 29 is an oil passage in the reduction gear housing 7 in the reduction gear 2, and the lubricating oil passage 29 includes a lubricating oil tank 29 a. The lubricating oil tank 29 a is provided at the lower portion of the reduction gear housing 7 and stores lubricating oil, and communicates with the in-motor lubricating oil storage portion 31 provided at the lower portion of the motor housing 8. The supply oil passage 30 is an oil passage for supplying the lubricating oil from the lubricating oil tank 29 a to the rotary electric motor 1 and the speed reducer 2.

  The pump 28 circulates the lubricating oil stored in the lubricating oil tank 29 a from the suction port in the lubricating oil tank 29 a to the supply oil passage 30. The pump 28 is disposed on the same axis between the rotary electric motor 1 and the speed reducer 2. The pump 28 includes, for example, an unillustrated inner rotor that rotates as the output member 4 rotates, an outer rotor that rotates following the rotation of the inner rotor, a pump chamber, a suction port, and a discharge port (both shown in the figure). (Not shown).

  When the inner rotor is rotated by the rotation of the output member 4 driven by the rotary electric motor 1, the outer rotor is driven to rotate. At this time, the inner rotor and the outer rotor rotate about different rotation centers, so that the volume of the pump chamber changes continuously. As a result, the lubricating oil stored in the lubricating oil tank 29 a is pumped to the supply oil passage 30. A part of the lubricating oil cools the rotor 10 and the stator coil 9b, then moves downward by gravity, and is stored in the in-motor lubricating oil reservoir 31 and the lubricating oil tank 29a, respectively.

  Also in the in-wheel motor drive device provided with this cycloid reduction gear, by providing the elastic member 20, the vibration resulting from the deformation | transformation of the stator 9 is reduced, and the axis of the stator 9 and the rotating shaft are made to correspond. Can do.

  The contact range between the elastic member 20 cast into the motor housing 8 and the stator 9 may be the entire circumference of the outer peripheral surface of the stator 9 as described above. For example, the contact range may be 10% of the outer peripheral surface of the stator 9. It may be a part.

  For example, as shown in FIG. 8, an elastic member 20 </ b> A may be interposed between the outer peripheral surface of the stator 9 and the inner peripheral surface of the motor housing 8 in a discontinuous manner in the circumferential direction. In this example, grooves 8b extending in the axial direction are formed on the inner peripheral surface of the motor housing 8 at regular intervals in the circumferential direction, and a plurality of elastic members 20A having an arc shape are formed in each groove 8b at regular intervals in the circumferential direction. It is provided every other. An elastic member 20A is cast and formed in each groove 8b formed on the inner peripheral surface of the motor housing 8, and the surface of each elastic member 20A that contacts the outer peripheral surface of the stator core 9a is a refined surface. Other configurations are the same as those of the above-described embodiment. When the groove 8b extending in the axial direction is provided in the motor housing 8, a method may be employed in which both the elastic member 20A and the groove 8b are inclined in the axial direction, and the elastic member 20A is fixed so as to be inserted into the groove 8b.

  According to the configuration of FIG. 8, the outer peripheral surface of the stator 9 is supported in contact with the refined surface of each elastic member 20 </ b> A, so that the entire stator can be supported in a floating manner with respect to the motor housing 8. Thereby, each elastic member 20 </ b> A dampens or absorbs vibration due to deformation of the stator 9. Further, since the outer peripheral surface of the stator 9 is abutted against and supported by the refinement surface of each elastic member 20A, the axis of the stator 9 can be aligned with the rotation axis. Cogging torque caused by deviation from the rotation axis can be reduced.

  The rotary electric motor 1 is not applied only to the in-wheel motor drive apparatus schematically shown in FIG. 9A, but as shown in FIG. 9B, a so-called motor onboard in which the rotary electric motor 1 is mounted on the vehicle body. Applicable to formats.

Although not shown in particular, after the elastic body is cast and molded not only at the location where the elastic body contacts the outer peripheral surface of the stator but also at the housing step, the axial end surface of the stator core on the outboard side of the elastic body comes into contact. The surface may be machined.
The rotary electric motor may be applied not only to a vehicle but also to an industrial machine.
The rotary motor may be an SPM (Surface Permanent Magnet Motor) synchronous motor.

  As mentioned above, although the form for implementing this invention based on embodiment was demonstrated, embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 ... Rotary motor 2 ... Reduction gear 6 ... Rotating shaft 8 ... Motor housing (housing)
8b ... Groove 9 ... Stator 9a ... Stator core 9b ... Stator coil 10 ... Rotor 11, 12 ... Bearing 20, 20A ... Elastic member

Claims (9)

A housing, an annular stator provided on the inner periphery of the housing, a rotating shaft that is rotatably supported by the housing via a bearing, and an integral part of the rotating shaft that is located radially inward of the stator In the rotary electric motor provided with the rotor arranged in
Between the outer peripheral surface of the stator and the inner peripheral surface of the housing, an elastic member is interposed continuously or discontinuously in the circumferential direction, and the surface of the elastic member is in contact with the outer peripheral surface of the stator. Rotating motor that is the precision surface.   2. The rotary motor according to claim 1, wherein the elastic member is made of a polymer material, and a linear expansion coefficient of the polymer material is larger than a linear expansion coefficient of the housing.   The rotary electric motor according to claim 1 or 2, wherein a groove in which an outer peripheral portion of the elastic member is accommodated is formed on an inner peripheral surface of the housing.   4. The rotary electric motor according to claim 1, wherein the elastic member has a radial thickness in a range of 5% to 80% of a radial thickness of the housing. 5. .   5. The rotary electric motor according to claim 1, wherein the stator includes a stator core and a stator coil wound around the stator core, and the axial range of the stator core includes the stator coil. A rotary electric motor provided with an elastic member.   The rotary electric motor according to any one of claims 1 to 5, wherein the housing is provided with a speed reducer that decelerates and outputs the rotation of the rotary shaft.   The in-wheel motor drive device provided with the wheel bearing which supports a wheel, and the rotary electric motor of any one of Claim 1 thru | or 6 which rotates the rotating wheel of this wheel bearing. A housing, an annular stator provided on the inner periphery of the housing, a rotating shaft that is rotatably supported by the housing via a bearing, and an integral part of the rotating shaft that is located radially inward of the stator A manufacturing method for manufacturing a rotary electric motor having a rotor arranged in
An elastic member installation process in which an elastic member is provided on the inner peripheral surface of the housing continuously or discontinuously in the circumferential direction over the entire circumference;
After this elastic member installation process, a refinement process in which the surface to be in contact with the outer peripheral surface of the stator in the elastic member is made into a refined surface by machining coaxially with the rotation center of the rotating shaft,
After this refinement process, the stator supporting process of contacting the outer peripheral surface of the stator with the refined surface of the elastic member and supporting the stator on the housing. 9. The method of manufacturing a rotary electric motor according to claim 8, wherein the elastic member installation process includes a process of casting the elastic member into a groove formed on an inner peripheral surface of the housing, and the refinement process includes: A method for manufacturing a rotary electric motor, comprising: machining an inner peripheral surface of the elastic member cast into a groove of the housing coaxially with a rotation center of the rotation shaft.

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