JP2023049272A - Rotor, rotary electric machine and drive device - Google Patents

Abstract

To provide a rotor capable of suppressing a change in magnetic characteristics of a magnet, a rotary electric machine and a drive device.SOLUTION: A rotor 30 comprises: an annular rotor core 32 centered on a center axis; a magnet 36 disposed in a magnet hole 38 extending in an axial direction of the rotor core 32; and at least one foam sheet 37 interposed between an inner wall of the magnet hole 38 and the magnet 36. The inner wall of the magnet hole 38 includes: a first wall surface 38a extending in a first direction in a view from the axial direction; a second wall surface 38b extending in the first direction in the view from the axial direction and opposed to the first wall surface 38a in a second direction orthogonal with the first direction; and a recess 38c disposed on the first wall surface 38a. The at least one foam sheet 37 is interposed between a first side face 36a of outer side faces of the magnet 36 opposed to the first wall surface 38a and the first wall surface 38a.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present invention relates to rotors, rotating electrical machines, and drive devices.

Conventionally, some rotors include a rotor core, permanent magnets inserted into holes of the rotor core, and adhesive sheets interposed between the holes and the permanent magnets (for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2006-311782

This type of rotor has room for improvement in terms of suppressing changes in the magnetic properties of the magnets.

An object of the present invention is to provide a rotor, a rotating electrical machine, and a driving device that can suppress changes in the magnetic properties of magnets.

One aspect of the rotor of the present invention includes an annular rotor core centered on a central axis, magnets arranged in magnet holes extending in the axial direction of the rotor core, and interposed between the inner wall of the magnet holes and the magnets. and at least one foam sheet for The inner wall of the magnet hole includes a first wall surface extending in a first direction when viewed from the axial direction, and a second wall surface extending in the first direction when viewed from the axial direction and extending in a second direction perpendicular to the first direction. It has a second wall surface facing the wall surface, and a recess arranged in the first wall surface. The at least one foam sheet is interposed between a first side surface facing the first wall surface of the magnet and the first wall surface.

One aspect of the rotating electric machine of the present invention includes the rotor described above and a stator arranged radially outside the rotor.

One aspect of the drive device of the present invention includes the rotating electric machine described above and a transmission device connected to the rotor.

According to the rotor, rotary electric machine, and driving device of the aspect of the present invention, changes in the magnetic properties of the magnet can be suppressed.

FIG. 1 is a schematic configuration diagram schematically showing the driving device of this embodiment. FIG. 2 is a front view of the rotor of this embodiment as seen from the axial direction, and the illustration of the shaft is omitted. 3 is a front view showing a portion of the rotor of FIG. 2; FIG. 4 is a front view showing an enlarged part of the rotor of FIG. 3. FIG. FIG. 5 is a side view showing a foam sheet. FIG. 6 is a perspective view showing a foam sheet. FIG. 7 is a perspective view explaining how to attach the foam sheet to the magnet. FIG. 8 is a front view showing part of the rotor of the first modified example of this embodiment. FIG. 9 is a front view showing part of the rotor of the second modified example of this embodiment. FIG. 10 is a front view showing part of the rotor of the third modified example of this embodiment. FIG. 11 is a front view showing part of a rotor of a fourth modified example of this embodiment. FIG. 12 is a front view showing an enlarged part of the rotor of the fifth modification of the present embodiment. FIG. 13 is a front view showing an enlarged part of the rotor of the sixth modification of the present embodiment. FIG. 14 is a cross-sectional view showing a rotor of a seventh modified example of this embodiment.

In the following description, the vertical direction is defined based on the positional relationship when the drive system of the embodiment is mounted on a vehicle positioned on a horizontal road surface. In other words, the relative positional relationship in the vertical direction, which will be described in the following embodiments, should be satisfied at least when the driving device is mounted on a vehicle positioned on a horizontal road surface.

In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is the vertical direction. The +Z side is vertically upward, and the -Z side is vertically downward. In the following description, the vertically upper side is simply called "upper side", and the vertically lower side is simply called "lower side". The X-axis direction is a direction orthogonal to the Z-axis direction and is the front-rear direction of the vehicle on which the driving device is mounted. In the following embodiments, the +X side is the front side of the vehicle and the -X side is the rear side of the vehicle. The Y-axis direction is a direction orthogonal to both the X-axis direction and the Z-axis direction, and is the left-right direction of the vehicle, that is, the vehicle width direction. In the following embodiments, the +Y side is the left side of the vehicle and the -Y side is the right side of the vehicle. The front-rear direction and the left-right direction are horizontal directions orthogonal to the vertical direction.

Note that the positional relationship in the longitudinal direction is not limited to the positional relationship in the following embodiments, and the +X side may be the rear side of the vehicle and the −X side may be the front side of the vehicle. In this case, the +Y side is the right side of the vehicle and the -Y side is the left side of the vehicle. Moreover, in this specification, the “parallel direction” includes substantially parallel directions, and the “perpendicular direction” includes substantially perpendicular directions.

A central axis J appropriately shown in the drawings is a virtual axis extending in a direction intersecting the vertical direction. More specifically, the central axis J extends in the Y-axis direction perpendicular to the vertical direction, that is, in the lateral direction of the vehicle. In the following description, unless otherwise specified, the direction parallel to the central axis J is simply referred to as the "axial direction", the radial direction about the central axis J is simply referred to as the "radial direction", and the central axis J is referred to as the "radial direction". The circumferential direction around the center, that is, the circumference of the central axis J is simply referred to as the "circumferential direction". The left side (+Y side) in the axial direction is called "one axial side", and the right side (−Y side) in the axial direction is called "the other axial side".

An arrow .theta. appropriately shown in the figure indicates the circumferential direction. In the following description, of the circumferential direction, the side that advances counterclockwise around the central axis J as viewed from the left side, that is, the side to which the arrow θ points (+θ side) is referred to as "one circumferential side". Of these, the side proceeding clockwise about the central axis J as viewed from the left side, that is, the side opposite to the side to which the arrow θ is directed (−θ side) is called the “other side in the circumferential direction”.

A drive device 100 of the present embodiment shown in FIG. 1 is mounted on a vehicle using a motor as a power source, such as a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHV), an electric vehicle (EV), etc., and is used as the power source. be done. That is, drive device 100 rotates axle 64 of the vehicle.

The drive device 100 includes a rotating electrical machine 10 and a transmission device 60 . The transmission device 60 is connected to a later-described rotor 30 of the rotating electrical machine 10, and transmits rotation of the rotor 30, that is, rotation of the rotating electrical machine 10, to an axle 64 of the vehicle. The transmission device 60 of this embodiment has a gear housing 61 , a reduction gear 62 connected to the rotor 30 , and a differential gear 63 connected to the reduction gear 62 .

The gear housing 61 accommodates the reduction gear 62, the differential gear 63, and the oil O inside. The oil O is stored in the lower area inside the gear housing 61 . The oil O circulates in a coolant flow path 90, which will be described later. Oil O is used as a coolant for cooling rotating electric machine 10 . Also, the oil O is used as a lubricating oil for the reduction gear 62 and the differential gear 63 . As the oil O, for example, it is preferable to use an oil equivalent to automatic transmission fluid (ATF), which has a relatively low viscosity, in order to function as a refrigerant and a lubricating oil.

The differential gear 63 has a ring gear 63a. Torque output from the rotary electric machine 10 is transmitted to the ring gear 63 a via the reduction gear 62 . A lower end of the ring gear 63 a is immersed in the oil O stored in the gear housing 61 . The oil O is scooped up by the rotation of the ring gear 63a. The scooped-up oil O is supplied to, for example, the reduction gear 62 and the differential gear 63 as lubricating oil.

The rotating electrical machine 10 is a part that drives the driving device 100 . The rotating electrical machine 10 is positioned, for example, on the other axial side of the transmission device 60 . In this embodiment, the rotating electric machine 10 is a motor. The rotary electric machine 10 includes a motor housing 20 , a rotor 30 rotatable around a central axis J, a stator 40 , and a coolant supply section 50 .

The motor housing 20 accommodates the rotor 30 and the stator 40 inside. The motor housing 20 is connected to the gear housing 61 on the other side in the axial direction. The motor housing 20 has a peripheral wall portion 21 , a partition wall portion 22 and a lid portion 23 . In this embodiment, the peripheral wall portion 21 and the partition wall portion 22 are integrally formed. The lid portion 23 is separate from the peripheral wall portion 21 and the partition wall portion 22 .

The peripheral wall portion 21 has a tubular shape surrounding the central axis J and opening on the other side in the axial direction. The partition wall portion 22 is connected to one axial end portion of the peripheral wall portion 21 . The partition wall 22 separates the interior of the motor housing 20 and the interior of the gear housing 61 in the axial direction. The partition wall portion 22 has a partition wall opening 22 a that connects the inside of the motor housing 20 and the inside of the gear housing 61 . A bearing 34 is held in the partition portion 22 . The lid portion 23 is fixed to the end portion of the peripheral wall portion 21 on the other side in the axial direction. The lid portion 23 closes the opening of the peripheral wall portion 21 on the other side in the axial direction. A bearing 35 is held in the lid portion 23 .

As shown in FIG. 2 , the rotor 30 has an annular rotor core 32 centered on the central axis J, magnets 36 , a foam sheet 37 and a shaft 31 . 2, illustration of the shaft 31 is omitted.

As shown in FIG. 1, shaft 31 extends axially and is fixed to rotor core 32 . Specifically, the outer peripheral surface of the shaft 31 and the inner peripheral surface of the central hole 32a of the rotor core 32, which will be described later, are fixed to each other. The shaft 31 is rotatable around the central axis J. As shown in FIG. Shaft 31 is rotatably supported by bearings 34 and 35 . The shaft 31 in this embodiment is a hollow shaft. The shaft 31 is cylindrical with the central axis J as the center. The shaft 31 is provided with a hole 33 that connects the inside of the shaft 31 and the outside of the shaft 31 . The shaft 31 extends across the interior of the motor housing 20 and the interior of the gear housing 61 . One axial end of the shaft 31 protrudes into the gear housing 61 . A reduction gear 62 is connected to one end of the shaft 31 in the axial direction.

As shown in FIG. 2, the rotor core 32 has a substantially cylindrical shape centered on the central axis J. As shown in FIG. The rotor core 32 has a central hole 32a that axially penetrates the rotor core 32 . The central hole 32a has a substantially circular shape centered on the central axis J. As shown in FIG. The shaft 31 is axially passed through the central hole 32a. The inner peripheral surface of the central hole 32 a is fixed to the outer peripheral surface of the shaft 31 .

The rotor core 32 is made of magnetic material. Although not shown, the rotor core 32 has a plurality of laminations stacked in the axial direction. A lamination is a plate-like member. The plate surface of the lamination faces the axial direction. The lamination has a substantially annular plate shape with the central axis J as the center. The lamination is, for example, electromagnetic steel sheets.

The rotor core 32 has a plurality of magnet holes 38 . Each magnet hole 38 is arranged in a portion of the rotor core 32 other than the central hole 32a. More specifically, when viewed from the axial direction, the magnet holes 38 are arranged radially outside and circumferentially spaced apart from the central hole 32a. Each magnet hole 38 axially penetrates the rotor core 32 . That is, the magnet hole 38 extends axially. A magnet 36 is arranged in each magnet hole 38 . That is, a plurality of magnets 36 are provided. One magnet 36 is arranged in each magnet hole 38 . The type of magnet 36 is not particularly limited. The magnet 36 may be, for example, a neodymium magnet or a ferrite magnet. As shown in FIG. 7, the magnet 36 has, for example, a rectangular parallelepiped shape elongated in the axial direction. The magnet 36 extends, for example, from one axial end of the rotor core 32 to the other axial end. The axial dimension of the magnet 36 may be shorter than the axial dimension of the rotor core 32 (the axial dimension of the magnet hole 38).

As shown in FIG. 3, the plurality of magnet holes 38 includes a first magnet hole 38A extending in a direction perpendicular to the radial direction when viewed from the axial direction, and a first magnet hole 38A extending radially outward when viewed from the axial direction. and a pair of second magnet holes 38B, 38C extending toward. Note that the first magnet hole 38A need not necessarily extend straight in the direction perpendicular to the radial direction, and may extend in the circumferential direction.

The pair of second magnet holes 38B and 38C are arranged adjacent to each other in the circumferential direction. Of the pair of second magnet holes 38B and 38C arranged in the circumferential direction, one of the second magnet holes 38B extends toward one side (+θ side) in the circumferential direction as it goes radially outward when viewed from the axial direction. Of the pair of second magnet holes 38B and 38C arranged in the circumferential direction, the other second magnet hole 38C extends toward the other circumferential side (−θ side) as it goes radially outward when viewed from the axial direction. . That is, the distance between the pair of second magnet holes 38B and 38C in the circumferential direction gradually increases toward the radially outer side. The first magnet hole 38A is arranged in the circumferential direction between the radially outer ends of the pair of second magnet holes 38B and 38C.

In this embodiment, as shown in FIG. 3, a set S of magnet holes 38 including one first magnet hole 38A and a pair of second magnet holes 38B and 38C is triangular when viewed from the axial direction. placed. That is, one first magnet hole 38A and two second magnet holes 38B and 38C included in one set S are arranged so as to form three sides of one substantially triangular shape when viewed from the axial direction. As shown in FIG. 2 , a plurality of sets S of magnet holes 38 are arranged in the rotor core 32 in the circumferential direction. In this embodiment, eight sets S of magnet holes 38 are provided at equal intervals in the circumferential direction. Note that the set S may also be referred to as a magnet hole gathering portion formed by gathering a plurality of magnet holes 38, or a magnet holding area which is an area for holding the magnet 36 when viewed from the axial direction.

In this embodiment, the magnets 36 arranged in the first magnet holes 38A are magnetized in the radial direction. That is, the radially outer portion of the magnet 36 arranged in the first magnet hole 38A is the N pole (or S pole). The radially inner portion of the magnet 36 arranged in the first magnet hole 38A has a magnetic pole (that is, S pole (or N pole)) that is different from the radially outer magnetic pole.

Similarly, in this embodiment, the magnets 36 arranged in the pair of second magnet holes 38B and 38C are magnetized in a direction perpendicular to the longitudinal direction of the magnets 36 when viewed from the axial direction. That is, the part on the other side in the circumferential direction of the magnet 36 arranged in one of the second magnet holes 38B is the N pole (or S pole). A portion of the magnet 36 arranged in the second magnet hole 38B on one side in the circumferential direction has a magnetic pole (that is, S pole (or N pole)) different from the magnetic pole on the other side in the circumferential direction.

The part on one side in the circumferential direction of the magnet 36 arranged in the other second magnet hole 38C is the N pole (or S pole). A portion of the magnet 36 located in the second magnet hole 38C on the other side in the circumferential direction has a magnetic pole (that is, S pole (or N pole)) different from the magnetic pole on the one side in the circumferential direction.

The first magnet hole 38A and the second magnet holes 38B, 38C have a configuration common to each other. The configuration common to the first magnet hole 38A and the second magnet holes 38B and 38C will be described below with reference to FIG. Note that FIG. 4 shows a first magnet hole 38A as an example of the magnet hole 38. As shown in FIG.

As shown in FIG. 4, the magnet hole 38 extends in the first direction D1 when viewed from the axial direction. The magnets 36 arranged in the magnet holes 38 also extend in the first direction D1 when viewed from the axial direction. The first direction D1 is, for example, a direction perpendicular to the magnetization direction of the magnet 36 when viewed from the axial direction. In the case of the first magnet hole 38A shown in FIG. 4, the first direction D1 is a direction perpendicular to the radial direction. The first direction D1 in the case of the second magnet holes 38B and 38C is, as shown in FIG. 3, a direction extending radially outward and circumferentially. That is, the first direction D1 in the case of the second magnet hole 38B is a direction extending toward one side in the circumferential direction as it goes radially outward, as shown in FIG. The first direction D1 in the case of the second magnet hole 38C is, as shown in FIG. 3, a direction extending toward the other side in the circumferential direction as it goes radially outward.

As shown in FIG. 4, the inner wall of the magnet hole 38 has a first wall surface 38a, a second wall surface 38b, a recess 38c, and a projection 38d. The first wall surface 38a extends in the first direction D1 when viewed from the axial direction. The first wall surface 38a is a surface facing the second direction D2 perpendicular to the first direction D1. The first wall surface 38a extends in a direction perpendicular to the second direction D2. In this embodiment, as shown in FIG. 3, each first wall surface 38a of the plurality of magnet holes 38 faces at least radially outward.

As shown in FIG. 4, the second wall surface 38b extends in the first direction D1 when viewed from the axial direction and faces the first wall surface 38a in the second direction D2. The second wall surface 38b is a surface facing the second direction D2. The second wall surface 38b extends in a direction perpendicular to the second direction D2. In this embodiment, as shown in FIG. 3, each second wall surface 38b of the plurality of magnet holes 38 faces at least radially inward.

As shown in FIG. 4, the recess 38c is arranged in the first wall surface 38a. The recess 38c is recessed in the second direction D2 from the first wall surface 38a and has a groove shape extending in the axial direction. In the present embodiment, the recess 38c has, for example, a semicircular or semielliptical cross-sectional shape perpendicular to the axial direction. However, the recess 38c is not limited to this, and the shape of the cross section perpendicular to the axial direction may be, for example, V-shaped or U-shaped. The recess 38c extends, for example, from one axial end of the rotor core 32 to the other axial end. In this embodiment, the recess 38c is arranged between both ends of the first wall surface 38a in the first direction D1. Specifically, one concave portion 38c is provided in the central portion of the first wall surface 38a in the first direction D1.

At least one protrusion 38 d is provided on the inner wall of the magnet hole 38 . In this embodiment, a plurality of protrusions 38 d are provided on the inner wall of the magnet hole 38 . Specifically, a pair of protrusions 38 d are provided on the inner wall of the magnet hole 38 . The pair of protrusions 38d are arranged apart from each other in the first direction D1. 38 d of protrusions protrude from the 1st wall surface 38a. The outer surface of the magnet 36 has two surfaces 36c extending along the second direction D2. On the outer surface of the magnet 36, two surfaces 36c of the magnet 36 are positioned apart in the first direction D1. The protrusion 38d faces a surface 36c of the outer surface of the magnet 36 extending along the second direction D2. In this embodiment, the pair of protrusions 38d faces the pair of surfaces 36c. More specifically, the projection 38d located on one side in the first direction D1 faces the surface 36c of the magnet 36 located on one side in the first direction D1. The projection 38d located on the other side in the first direction D1 faces the surface 36c of the magnet 36 located on the other side in the first direction D1. The protrusion 38d may be in contact with the surface 36c, or may be opposed to the surface 36c with a gap therebetween.

A foam sheet 37 is interposed between the inner wall of the magnet hole 38 and the magnet 36 . As shown in FIG. 7, the foam sheet 37 is a sheet-like member, and is inserted into the magnet hole 38 together with the magnet 36 while attached to the outer surface of the magnet 36 . In this embodiment, the foam sheet 37 is in the form of a rectangular, ie, square, sheet extending in the axial direction. However, the foam sheet 37 is not limited to this, and may have a sheet shape such as a polygonal shape other than a square shape, an elliptical shape, or a circular shape. The foam sheet 37 arranged in the magnet hole 38 is foamed by heating, expands in volume, and hardens in the expanded state. The expanded foam sheet 37 presses the magnet 36 toward the inner wall of the magnet hole 38 . The foam sheet 37 thereby holds the magnet 36 in the magnet hole 38 .

As shown in FIG. 5, the foam sheet 37 is constructed by laminating a plurality of layers. In this embodiment, the foam sheet 37 has a base layer 37a, a pair of foam adhesive layers 37b and 37c, and a release liner 37e.

The base material layer 37a is film-like and is made of resin, for example. The base material layer 37a is made of, for example, polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyethylene terephthalate (PET), or polyimide (PI).

Each of the pair of foamed adhesive layers 37b and 37c contains, for example, a thermosetting resin and a foaming agent that can be foamed by heating. The foaming agent preferably foams at a temperature lower than the curing temperature of the thermosetting resin and reaches the maximum expanded state (maximum foamed state). As a result, in the process of increasing the temperature when the rotor is heated, the curing of the thermosetting resin is started after the foaming of the foaming agent is completed. The magnet 36 can be stably fixed to the inner wall of the magnet hole 38 .

As the foaming agent, an organic solvent having a low melting point, such as a microcapsule containing an alcohol or the like can be used. Moreover, it is preferable that the thermosetting resin is composed of a thermosetting adhesive. Examples of the thermosetting adhesive include phenol-based adhesives, urethane-based adhesives, and epoxy-based adhesives. It is more preferable to use an epoxy-based adhesive as the thermosetting adhesive because it is excellent in adhesive strength, chemical resistance, and the like.

Of the pair of foamed adhesive layers 37b and 37c, one foamed adhesive layer 37b is arranged on one surface (for example, the surface) of the base material layer 37a, and the other foamed adhesive layer 37c is arranged on the other side of the base material layer 37a. It is placed on the face (for example, the back face). The other foam adhesive layer 37c has an adhesive surface 37d on the surface of the foam sheet 37 facing away from the base material layer 37a in the thickness direction.

A release liner 37e covers the adhesive surface 37d. As shown in FIG. 6, a release liner 37e is releasably attached to the adhesive surface 37d. The release liner 37 e is removed from the foam sheet 37 when attaching the foam sheet 37 to the magnet 36 . As shown in FIG. 7, the foam sheet 37 is attached to the magnet 36 by attaching the adhesive surface 37d exposed by removing the release liner 37e to the outer surface of the magnet 36. As shown in FIG.

As shown in FIG. 4 , at least one foam sheet 37 is provided between the inner wall of the magnet hole 38 and the magnet 36 . At least one foam sheet 37 is interposed between the first wall surface 38a and a first side surface 36a of the outer surface of the magnet 36 that faces the first wall surface 38a. In this embodiment, the recess 38 c of the first wall surface 38 a is arranged to face the foam sheet 37 . According to the present embodiment, for example, the opening edge of the concave portion 38c is caught on the surface of the foam sheet 37, so that it is possible to suppress the displacement of the foam sheet 37 in the first direction D1. positional deviation of the magnet 36 in the first direction D1 can be suppressed. Therefore, it is possible to suppress changes in the magnetic characteristics due to positional displacement, rattling, and the like of the magnet 36 .

Further, in the present embodiment, as indicated by the arrows in FIG. 3, the foam sheet 37 expanded by heating pushes the magnets 36 at least radially outward when the rotor 30 is manufactured. Among them, the second side surface 36b facing the second wall surface 38b is pressed against the second wall surface 38b. By hardening the foam sheet 37 in this state, the second side surface 36b of the magnet 36 and the second wall surface 38b of the magnet hole 38 are kept in close contact with each other. Therefore, even if centrifugal force acts on the magnets 36 when the rotor 30 rotates, the magnets 36 are prevented from being displaced radially outward within the magnet holes 38 .

Moreover, in this embodiment, as shown in FIG. 4, the foam sheet 37 is arranged between the pair of projections 38d. Therefore, the foam sheet 37 can be positioned in the first direction D1 within the magnet hole 38 using the pair of projections 38d. More specifically, in this embodiment, the foam sheet 37 and the magnet 36 are arranged between two adjacent projections 38d in the first direction D1. Therefore, the foam sheet 37 and the magnet 36 can be pressed on both sides in the first direction D1 by the plurality of protrusions 38d. It is possible to stably prevent the foam sheet 37 and the magnet 36 from slipping out of the magnet hole 38 .

The magnet hole 38 has a flux barrier portion 38e. The flux barrier portion 38e is arranged adjacent to the magnet 36 in the first direction D1. In this specification, the term “flux barrier portion” means a portion capable of suppressing the flow of magnetic flux. In other words, it is difficult for the magnetic flux to pass through the flux barrier portion. The flux barrier portion is not particularly limited as long as it can suppress the flow of magnetic flux, and may include a void portion or a non-magnetic portion such as a resin portion. In the present embodiment, the flux barrier portion 38e is a gap formed by a hole penetrating the rotor core 32 in the axial direction. In this embodiment, a pair of flux barrier portions 38e are provided at both ends of the magnet hole 38 in the first direction D1.

As shown in FIG. 1, the stator 40 faces the rotor 30 with a gap in the radial direction. More specifically, the stator 40 is arranged radially outside the rotor 30 . The stator 40 is fixed inside the motor housing 20 . Stator 40 includes stator core 41 and coil assembly 42 .

The stator core 41 has an annular shape surrounding the central axis J of the rotary electric machine 10 . The stator core 41 is positioned radially outside the rotor 30 . Stator core 41 surrounds rotor 30 . The outer peripheral surface of stator core 41 has a portion that contacts the inner peripheral surface of motor housing 20 . The stator core 41 is fixed to the motor housing 20 by fastening members such as bolts (not shown).

The coil assembly 42 has a plurality of coils 42c attached to the stator core 41 along the circumferential direction. The plurality of coils 42c are arranged on the stator core 41 via a member made of an insulating material (not shown). A plurality of coils 42c are arranged along the circumferential direction. More specifically, the plurality of coils 42c are arranged at regular intervals along the circumferential direction. Although not shown, the coil assembly 42 may have a binding member or the like that binds the coils 42c, or may have a connecting wire that connects the coils 42c.

The coil assembly 42 has coil ends 42 a and 42 b axially protruding from the stator core 41 . The coil end 42a is a portion that protrudes from the stator core 41 to one side in the axial direction. The coil end 42b is a portion protruding from the stator core 41 to the other side in the axial direction. Coil end 42 a includes a portion of each coil 42 c included in coil assembly 42 that protrudes to one side in the axial direction from stator core 41 . Coil end 42 b includes a portion of each coil 42 c included in coil assembly 42 that protrudes to the other side in the axial direction from stator core 41 . In this embodiment, the outer appearance of the coil ends 42a and 42b is substantially annular with the center axis J as the center when viewed from the axial direction. Although not shown, the coil ends 42a and 42b may include a binding member or the like that binds the coils 42c, or may include a connecting wire that connects the coils 42c.

The coolant supply part 50 has a tubular shape extending in the axial direction. In this embodiment, the coolant supply portion 50 is a pipe extending in the axial direction. Both axial ends of the coolant supply portion 50 are supported by the motor housing 20 . One end in the axial direction of the coolant supply portion 50 is supported by, for example, the partition wall portion 22 . The end portion of the coolant supply portion 50 on the other side in the axial direction is supported by, for example, the lid portion 23 . The coolant supply portion 50 is positioned radially outward of the stator 40 . In this embodiment, the coolant supply unit 50 is positioned above the stator 40 .

The coolant supply unit 50 has a supply port 50a that supplies oil O as a coolant to the stator 40 . In the present embodiment, the supply port 50a is a jetting port that jets part of the oil O that has flowed into the coolant supply portion 50 to the outside of the coolant supply portion 50 . A plurality of supply ports 50 a are provided in the coolant supply section 50 .

In the present embodiment, the driving device 100 is provided with a coolant channel 90 through which oil O as a coolant circulates. The coolant flow path 90 is provided across the inside of the motor housing 20 and the inside of the gear housing 61 . The coolant flow path 90 is a path through which the oil O stored in the gear housing 61 is supplied to the rotary electric machine 10 and returns to the gear housing 61 again. A pump 71 , a cooler 72 , and a coolant supply section 50 are provided in the coolant channel 90 . The coolant channel 90 has a first channel portion 91 , a second channel portion 92 , a third channel portion 93 , a fourth channel portion 94 and a fifth channel portion 95 . In the present embodiment, the fifth channel portion 95 may be called a "channel".

The first channel portion 91 , the second channel portion 92 , and the third channel portion 93 are provided on the wall portion of the gear housing 61 , for example. The fourth channel portion 94 is provided in the lid portion 23, for example. The first flow path portion 91 connects a portion of the gear housing 61 where the oil O is stored and the pump 71 . The second channel portion 92 connects the pump 71 and the cooler 72 . The third channel portion 93 connects the cooler 72 and the interior of the coolant supply portion 50 . In the present embodiment, the third flow path portion 93 is connected to one axial end portion of the coolant supply portion 50 . The fourth channel portion 94 connects the inside of the coolant supply portion 50 and the inside of the shaft 31 . In the present embodiment, the fourth flow path portion 94 is connected to the other axial end of the coolant supply portion 50 and the other axial end of the shaft 31 .

The fifth channel portion 95 , that is, the channel, is arranged over at least the inside of the shaft 31 and the inside of the rotor core 32 . That is, the rotor 30 includes a fifth channel portion 95 that is a channel. The channel has a shaft channel 95a arranged inside the shaft 31 and a concave channel 95b connected to the shaft channel 95a and arranged inside the concave portion 38c. In the present embodiment, the shaft flow path 95a and the recessed flow path 95b connect the hole 33 of the shaft 31 and the hole 33 and the recessed flow path 95b and extend through the rotor core 32 (not shown). connected to each other through The concave passage 95b extends over the entire length of the rotor core 32 in the axial direction. In the present embodiment, part of the oil O that has flowed from the shaft flow path 95a into the recessed flow path 95b through the hole 33 and the communication flow path flows toward one side in the axial direction of the recessed flow path 95b, and Another portion of the oil O that has flowed into the recessed flow path 95b flows through the recessed flow path 95b toward the other side in the axial direction.

The oil O stored in the gear housing 61 is sucked up by the pump 71 through the first channel portion 91 and flows from the pump 71 through the second channel portion 92 into the cooler 72 . The oil O that has flowed into the cooler 72 is cooled in the cooler 72 and then flows into the coolant supply section 50 through the third flow path section 93 . A portion of the oil O that has flowed into the coolant supply portion 50 is injected from the supply port 50 a and supplied to the stator 40 . Another portion of the oil O that has flowed into the coolant supply portion 50 flows into the interior of the shaft 31 through the fourth flow path portion 94 . A portion of the oil O that has flowed into the shaft 31 passes through the shaft channel 95a, the hole 33, the communication channel, and the recessed channel 95b, and scatters to the stator 40. As shown in FIG. Another part of the oil O that has flowed into the shaft 31 passes through the shaft flow path 95a, is discharged into the gear housing 61 from the opening on one side in the axial direction of the shaft 31, and is stored in the gear housing 61 again. be.

The oil O supplied to the rotor 30 and stator 40 takes heat from the rotor 30 and stator 40 . The oil O that has cooled the rotor 30 and the stator 40 drops downward and accumulates in the lower area inside the motor housing 20 . The oil O accumulated in the lower region inside the motor housing 20 returns into the gear housing 61 through the partition wall opening 22 a provided in the partition wall portion 22 . As described above, the coolant flow path 90 supplies the oil O stored in the gear housing 61 to the rotor 30 and the stator 40 .

As shown in FIG. 4, in the present embodiment, the magnet 36 can be cooled by the flow of the oil O as a coolant through the concave passage 95b. That is, since the oil O flows into the concave portion 38c, the magnet 36 can be cooled through the foam sheet 37, and the change in the magnetic properties of the magnet 36 due to the temperature rise can be suppressed. Further, when an impact is applied to the rotating electric machine 10 from the outside and is transmitted to the rotor 30, an effect (damper effect) of attenuating the vibration by the oil O flowing through the concave passage 95b can be obtained.

It should be noted that the present invention is not limited to the above-described embodiments, and, for example, as described below, changes in configuration can be made without departing from the gist of the present invention. In the drawings of the respective modifications, the same reference numerals are given to the same constituent elements as in the above-described embodiment, and mainly different points will be described below.

FIG. 8 is a partial front view showing a first modification of the rotor 30 described in the above embodiment. In the first modification shown in FIG. 8, a plurality of recesses 38c are provided on the inner wall of the magnet hole 38 at intervals in the first direction D1. That is, a plurality of recesses 38c are provided on the first wall surface 38a. In addition, a recessed channel 95b is arranged in each recessed portion 38c. As described above, the rotor core 32 and the magnets 36 can be further cooled by the oil O flowing through the at least one recessed passage 95b. In addition, since the oil O flows into at least one recessed flow path 95b, when an impact from the outside is transmitted to the rotor 30, the impact can be softened by the oil O inside the recessed flow path 95b.

The recesses 38c provided in the first wall surface 38a may be provided at regular intervals in the first direction D1, or the distances between the adjacent recesses 38c may be different. Further, when viewed from the axial direction, the cross-sectional shape of each recess 38c and the width of the opening in the first direction D1 may be the same or different. When three or more recesses 38c are provided, at least two recesses 38c may have the same cross-sectional shape and the same opening width in the first direction D1.

FIG. 9 is a partial front view showing a second modification of the rotor 30 described in the above embodiment. In the second modification shown in FIG. 9, a plurality of foam sheets 37 are provided between the first wall surface 38a and the first side surface 36a and are arranged side by side in the first direction D1. That is, a plurality of foam sheets 37 are provided along the first direction D1. The shape of each foam sheet 37 in the second modification is a rectangle extending in the axial direction. Note that the shape of the foam sheet 37 is not particularly limited.

Also in the second modification shown in FIG. 9, a plurality of recesses 38c are provided on the first wall surface 38a. At least one of the plurality of recesses 38 c faces the foam sheet 37 and at least one of the recesses 38 c does not face the foam sheet 37 . In the example shown in FIG. 9, three recesses 38c are provided on the first wall surface 38a. , the foam sheet 37 and the other two recesses 38 c arranged on both sides of the one recess 38 c in the first direction D<b>1 do not face the foam sheet 37 . In the above-described embodiment, the foam sheet 37 covers the recess 38c, but in the second modification, at least one of the plurality of foam sheets 37 does not cover the recess 38c. Therefore, the volume of the foam sheet 37 interposed between the first wall surface 38a and the magnet 36 in the second modified example is the volume of the foam sheet 37 interposed between the first wall surface 38a and the magnet 36 in the above-described embodiment. smaller than

Even with the structure shown in the second modified example, the expansion and hardening of each foam sheet 37 presses the magnets 36 against the inner walls of the magnet holes 38 to hold the magnets 36 in the magnet holes 38 . As described above, in the second modified example, the volume of the foam sheet 37 is smaller than that of the above-described embodiment, so the amount of foam sheet 37 used is reduced. Therefore, costs related to the foam sheet 37 can be reduced.

In addition, when the concave portion 38c that is not arranged to face the foam sheet 37 is provided, the oil O as a coolant flows through the concave portion 38c, so that the magnet 36 can be directly cooled by the oil O. Therefore, it is possible to further suppress changes in the magnetic properties due to temperature rise of the magnet 36 .

In addition, in the second modification, as shown in FIG. 8, all of the plurality of recesses 38c provided in the inner wall of the magnet hole 38 may be arranged facing the foam sheet 37, or they may not be shown. However, not all of the plurality of recesses 38 c need to be arranged facing the foam sheet 37 .

FIG. 10 is a partial front view showing a third modification of the rotor 30 described in the above embodiment. In the third modification shown in FIG. 10, the first wall surface 38a of the magnet hole 38 has a projecting wall portion 38f projecting in the second direction D2. The projecting wall portion 38f is arranged between both ends of the first wall surface 38a in the first direction D1. A surface of the projecting wall portion 38f facing the second direction D2 faces the first side surface 36a of the magnet 36. As shown in FIG. A plurality of foam sheets 37 are provided at intervals in the first direction D1. In the example shown in FIG. 10, a pair of foam sheets 37 are provided at both ends of the first wall surface 38a in the first direction D1. Each foam sheet 37 is interposed between the portion of the first wall surface 38a other than the projecting wall portion 38f and the first side surface 36a.

Also in the third modification shown in FIG. 10, a plurality of recesses 38c are provided on the first wall surface 38a. The plurality of recesses 38c includes at least one recess 38c arranged in a portion of the first wall surface 38a other than the protruding wall 38f and at least one other recess 38c arranged in the protruding wall 38f. include. The one concave portion 38 c faces the foam sheet 37 . The other concave portion 38 c does not face the foam sheet 37 but faces the first side surface 36 a of the magnet 36 . When viewed from the axial direction, the cross-sectional shape of the one recess 38c may be different from or the same as the cross-sectional shape of the other recess 38c. When viewed from the axial direction, all of the other recesses 38c may have the same cross-sectional shape, or may include those having the same cross-sectional shape.

In addition, in the third modified example, one concave portion (the other concave portion 38c) is provided in the projecting wall portion 38f. However, the projecting wall portion 38f may be provided with a plurality of recesses (other recesses 38c).

Note that, as shown in the above-described embodiment and modification, the oil O may flow into at least one recess 38c among the plurality of recesses 38c. Thereby, the magnets 36 and the rotor core 32 can be cooled.

In the above-described embodiment, the foam sheet 37 covers the recess 38c, but in the third modification, the foam sheet 37 covers at least part of the recess 38c (the one recess 38c). The foam sheet 37 does not cover at least one recess 38c (the other recess 38c). Therefore, similarly to the second modification, the volume of the foam sheet 37 interposed between the first wall surface 38a and the magnet 36 in the third modification is the same as the volume between the first wall surface 38a and the magnet 36 in the above-described embodiment. is smaller than the volume of the foam sheet 37 intervening in the Even with the structure shown in the third modified example, the expansion and hardening of each foam sheet 37 presses the magnets 36 against the inner walls of the magnet holes 38 to hold the magnets 36 in the magnet holes 38 . As described above, in the third modified example, the volume of the foam sheet 37 is smaller than that of the above-described embodiment, so the amount of foam sheet 37 used is reduced. Therefore, costs related to the foam sheet 37 can be reduced.

FIG. 11 is a partial front view showing a fourth modification of the rotor 30 described in the above embodiment. In a fourth modification shown in FIG. 11, recesses 38c are also provided in the second wall surface 38b. Specifically, the recess 38c includes a first recess 38ca arranged on the first wall surface 38a and a second recess 38cb arranged on the second wall surface 38b. A plurality of first recesses 38ca are provided on the first wall surface 38a so as to be aligned in the first direction D1. A plurality of second recesses 38cb are provided on the second wall surface 38b so as to be aligned in the first direction D1.

In the fourth modification shown in FIG. 11, a plurality of foam sheets 37 are provided. The plurality of foam sheets 37 includes a first foam sheet 37A interposed between the first side surface 36a and the first wall surface 38a, and a second foam sheet 37B interposed between the second side surface 36b and the second wall surface 38b. ,including.

In the fourth modification shown in FIG. 11, the first foam seat 37A and the second foam seat 37B are arranged side by side in the first direction D1. Specifically, the second foam sheet 37B is arranged on one side of the second wall surface 38b in the first direction D1, and the first foam sheet 37A is arranged on the other side of the first wall surface 38a in the first direction D1. placed in the part of In the example shown in FIG. 11, one side in the first direction D1 corresponds to one side in the circumferential direction (+θ side), and the other side in the first direction D1 corresponds to the other side in the circumferential direction (−θ side). Thus, in the fourth modification, the position where the first foam seat 37A is provided and the position where the second foam seat 37B is provided are shifted from each other in the first direction D1.

In the fourth modification, when the foam sheet 37 expands due to heating, as indicated by arrows in FIG. are different from each other in the direction in which they push the second side surface 36b of the magnet 36 . Therefore, the magnet 36 is fixed in a state of being inclined with respect to the magnet hole 38 . More specifically, when viewed from the axial direction, the magnet 36 is held in an inclined state with respect to the first wall surface 38a and the second wall surface 38b. In other words, the first side surface 36a of the magnet 36 is inclined with respect to the first wall surface 38a. A second side surface 36b of the magnet 36 is inclined with respect to the second wall surface 38b. This makes it more difficult for the magnets 36 to be displaced in the magnet holes 38 even when centrifugal force or the like acts during rotation of the rotor 30 .

Note that, as shown in the above-described embodiment and modification, the oil O may flow into at least one of the plurality of first recesses 38ca and 38cb. Thereby, the magnets 36 and the rotor core 32 can be cooled.

Moreover, when viewed from the axial direction, the cross-sectional shapes of at least one first recess 38ca and at least one second recess 38cb may all be the same, or at least one of them may be different.

In the fourth modification, the position of the first recess 38ca in the first direction D1 is substantially the same as the position of the second recess 38cb in the first direction D1. In other words, the first recess 38ca faces the second recess 38cb in the second direction D2. However, the position of the at least one first recess 38ca in the first direction D1 may be the same as or different from the position of the at least one second recess 38cb in the first direction D1.

FIG. 12 is a partial front view showing a fifth modification of the rotor 30 described in the above embodiment, showing an enlarged view of the vicinity of the recess 38c. In a fifth modification shown in FIG. 12, the rotor 30 is provided with an adhesive 39 provided in the magnet holes 38 . Adhesive 39 is placed in recess 38c. More specifically, the adhesive 39 is cured while being placed in the recess 38c. According to the fifth modification, at least a portion of the adhesive 39 is in contact with the foam sheet 37, thereby suppressing relative displacement of the concave portion 38c and the foam sheet 37 in the first direction D1. Further, when an impact is applied to the rotating electric machine 10 from the outside and transmitted to the rotor 30, the effect of damping the vibration (damper effect) is obtained by the adhesive 39 in the recess 38c.

Moreover, in the fifth modification shown in FIG. 12, the adhesive 39 has a portion 39a that protrudes in the second direction D2 from the first wall surface 38a. In this case, a portion 39 a of the adhesive 39 that protrudes from the first wall surface 38 a can come into contact with the foam sheet 37 . Thereby, the displacement of the foam sheet 37 in the first direction D1 can be further suppressed. In addition, the above damper effect can be obtained more remarkably. The shape of the projecting portion 39a is not limited to that shown in the drawing.

FIG. 13 is a partial front view showing a sixth modification of the rotor 30 described in the above embodiment, showing an enlarged view of the vicinity of the recess 38c. In the sixth modification shown in FIG. 13, the foam sheet 37 has a portion 37f that enters the recess 38c. The entering portion 37f is placed in the recess 38c and hardened, for example, when the foam sheet 37 is expanded by heating. According to the sixth modification, a portion of the foam sheet 37 enters the recess 38c, thereby further suppressing displacement of the foam sheet 37 in the first direction D1.

FIG. 14 is a cross-sectional view showing a seventh modification of the rotor 30 described in the above embodiment. In a seventh modification shown in FIG. 14, a rotor 30 includes a pair of end plates 51 arranged at both ends of a rotor core 32 in the axial direction. The end plate 51 has, for example, a substantially annular plate shape centered on the central axis J. As shown in FIG. In the seventh modification, end plate 51 is fixed to rotor core 32 . The end plate 51 axially covers at least a portion of the magnet hole 38 and at least a portion of the recess 38c. According to the seventh modification, the end plate 51 prevents foreign matter from entering the magnet hole 38 and the recess 38c, and prevents the magnet 36 from falling off from the rotor core 32 .

14, a shaft flow path 95a and a recessed flow path 95b connect the hole 33 of the shaft 31, and the hole 33 and the recessed flow path 95b to extend through the end plate 51. They are connected to each other via the extending end plate channels 95c. Further, the oil O that has flowed from the shaft flow path 95a into the recessed flow path 95b through the hole 33 and the end plate flow path 95c flows toward one side in the axial direction of the recessed flow path 95b.

Further, as shown in FIGS. 1 and 4, even if the fifth flow path portion 95, that is, the flow path, has a flux barrier flow path 95d that is connected to the shaft flow path 95a and arranged within the flux barrier portion 38e. good. In this case, the magnet 36 can be cooled by the oil O as a coolant flowing through the flux barrier channel 95d. Further, when an impact is applied to the rotating electric machine 10 from the outside and transmitted to the rotor 30, an effect of damping vibration (damper effect) is obtained by the oil O flowing through the flux barrier flow path 95d.

Moreover, in the above-described embodiment, as shown in FIG. 3, the example in which the set S of the three magnet holes 38 is arranged in a triangular shape when viewed from the axial direction was given, but the present invention is not limited to this. That is, the number, arrangement, etc. of the magnet holes 38 included in the set S are not limited to the above-described embodiment. For example, the set S may have the first magnet hole 38A and not the second magnet holes 38B and 38C. Alternatively, the set S may have the second magnet holes 38B and 38C and not the first magnet hole 38A. Further, the set S may have a configuration in which a plurality of first magnet holes 38A are arranged side by side in the radial direction. Alternatively, the set S may have a configuration in which a plurality of second magnet holes 38B and 38C are arranged side by side in the radial direction.

Moreover, the coolant circulating in the coolant flow path 90 is not limited to the oil O. The coolant may be, for example, an insulating liquid or water. When the coolant is water, the surface of the stator 40 may be subjected to insulation treatment.

A rotating electric machine to which the present invention is applied is not limited to a motor, and may be a generator. Applications of the rotating electric machine are not particularly limited. For example, the rotating electric machine may be mounted on a vehicle for a purpose other than for rotating the axle 64, or may be mounted on a device other than the vehicle. In addition, there are no particular restrictions on the orientation of the rotating electric machine when it is used.

The configurations described in the above-described embodiments and modifications may be combined without departing from the gist of the present invention, and addition, omission, replacement, and other modifications of the configuration are possible. Moreover, the present invention is not limited by the above-described embodiments and the like, but is limited only by the scope of the claims.

DESCRIPTION OF SYMBOLS 10... Rotating electric machine 30... Rotor 31... Shaft 32... Rotor core 36... Magnet 36a... First side surface 36b... Second side surface 37... Foam sheet 37f... Part of foam sheet that enters into recess, 37A... first foam sheet, 37B... second foam sheet, 38... magnet hole, 38a... first wall surface, 38b... second wall surface, 38c... concave portion, 38ca... first concave portion, 38cb... second concave portion, 38d... projection , 38e... Flux barrier part 39... Adhesive 39a... Portion of adhesive protruding in second direction from first wall surface 40... Stator 51... End plate 60... Transmission device 95a... Shaft flow path, 95b... concave passage, 95d... flux barrier passage, 100... driving device, D1... first direction, D2... second direction, J... center axis

Claims (14)

an annular rotor core centered on the central axis;
magnets arranged in magnet holes extending in the axial direction of the rotor core;
At least one foam sheet interposed between the inner wall of the magnet hole and the magnet,
The inner wall of the magnet hole is
a first wall surface extending in a first direction when viewed from the axial direction;
a second wall surface extending in the first direction when viewed from the axial direction and facing the first wall surface in a second direction orthogonal to the first direction;
a recess disposed on the first wall surface;
The at least one foam sheet is interposed between a first side surface facing the first wall surface of the magnet and the first wall surface,
rotor. the inner wall of the magnet hole has a pair of projections projecting from the first wall surface and arranged apart from each other in the first direction;
The foam sheet is disposed between the pair of protrusions,
A rotor according to claim 1 . A plurality of the recesses are provided on the first wall surface,
A rotor according to claim 1 or 2. A plurality of the foam sheets are provided along the first direction,
A rotor according to any one of claims 1 to 3. A plurality of the foam sheets are provided,
The plurality of foam sheets are
a first foam sheet interposed between the first side surface and the first wall surface;
a second foam sheet interposed between a second side surface facing the second wall surface of the outer side surface of the magnet and the second wall surface,
The recess is also provided on the second wall surface,
The recess is
a first recess disposed on the first wall surface;
a second recess disposed on the second wall surface;
A rotor according to any one of claims 1 to 4. The first foam sheet and the second foam sheet are arranged side by side in the first direction,
A rotor according to claim 5 . a shaft extending axially and fixed to the rotor core;
a flow path arranged over at least the shaft and the rotor core,
The flow path is
a shaft channel disposed within the shaft;
a recessed channel connected to the shaft channel and disposed within the recessed portion;
A rotor according to any one of claims 1 to 6. the magnet hole has a flux barrier portion arranged adjacent to the magnet in the first direction;
The flow path has a flux barrier flow path connected to the shaft flow path and disposed within the flux barrier section.
A rotor according to claim 7 . A pair of end plates arranged at both ends of the rotor core in the axial direction,
The end plate axially covers at least part of the magnet hole and at least part of the recess,
A rotor according to any one of claims 1 to 8. An adhesive provided in the magnet hole,
the adhesive is disposed within the recess;
A rotor according to any one of claims 1 to 9. The adhesive has a portion that protrudes in the second direction from the first wall surface,
A rotor according to claim 10 . The foam sheet has a portion that enters into the recess,
A rotor according to any one of claims 1 to 11. a rotor according to any one of claims 1 to 12;
a stator arranged radially outside the rotor;
rotating electric machine. a rotating electric machine according to claim 13;
a transmission device connected to the rotor;
drive.

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