Rotating electric machine and drive unit

Abstract

To provide a rotary electric machine by which cooling efficiency is improved for a rotor and a stator, and to provide a driving device thereof.SOLUTION: A rotary electric machine 10 comprises: a rotor 30 provided with a shaft 1 into which oil O is flowable; and a stator located on an outer side of the rotor 30 in a radial direction. The shaft 1 comprises: a cylindrical shaft body 2 provided with a plurality of first side holes 22 that penetrate in a radial direction; and a cylindrical body 5 inserted into one side of the shaft body 2 in an axis J direction and provided with a plurality of plate-like parts 55 provided on the one side in the axis J direction and arranged adjacent to each other around the axis J via a slit 54. According to each of the plate-like parts 55, the one side in the axis J direction comes into contact with the shaft body 2 in an attachment state where the cylindrical body 5 is attached to the shaft body 2. Further, an inside of the cylindrical body 5 and each of the first side holes 22 are connected via between the shaft body 2 and the slit 54 as well as each of the plate-like parts 55, thereby serving as a flow passage 12 through which the oil O can pass.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine and a drive device. [Background technology]

[0002] 2. Description of the Related Art There is known an electric motor that includes a rotor having a rotating shaft, and a stator in which the rotor is disposed inside and which drives the rotor to rotate by a rotating magnetic field (see, for example, Patent Document 1). The rotor of the electric motor described in Patent Document 1 has a hollow rotating shaft. By circulating a coolant such as cooling oil inside the rotating shaft, the temperature rise of the rotor can be suppressed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-235210 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the electric motor described in Patent Document 1, since the coolant passes through the rotating shaft, it is possible to suppress the temperature rise of the rotor, but it is difficult to suppress the temperature rise of the stator as well. In other words, in the electric motor described in Patent Document 1, the cooling efficiency for both the rotor and the stator is low. An object of the present invention is to provide a rotating electric machine and a drive unit that improve the cooling efficiency for a rotor and a stator. [Means for solving the problem]

[0005] One aspect of the rotating electric machine of the present invention is a rotor having a shaft through which a coolant can flow and capable of rotating about the shaft; a stator positioned radially outward of the rotor, The shaft is a cylindrical shaft body having a plurality of first side holes extending radially therethrough; a cylindrical body that is inserted into one axial side of the shaft body, the cylindrical body having a plurality of plate-like portions provided on the one axial side and arranged adjacent to each other around the axis with slits interposed therebetween; When the cylindrical body is attached to the shaft body, one axial side of each of the plate-shaped portions contacts the shaft body, and the inside of the cylindrical body and each of the first side holes are connected via the slits and between each of the plate-shaped portions and the shaft body, functioning as a flow path through which the refrigerant can pass.

[0006] One embodiment of the drive device of the present invention is a drive device mounted on a vehicle and configured to rotate an axle, comprising: The rotating electric machine described above; a transmission device connected to the rotating electric machine and configured to transmit rotation of the rotor to the axle; a housing that accommodates the rotating electric machine and the transmission device; The rotating electric machine further comprises a coolant passage provided within the housing for supplying a coolant to the shaft and the stator of the rotating electric machine. Effect of the Invention

[0007] According to the rotating electric machine and drive device of one aspect of the present invention, the cooling efficiency for the rotor and the stator is improved. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a drive device according to an embodiment. [Diagram 2] FIG. 2 is a schematic vertical cross-sectional view showing a state before assembly of a shaft of a rotor in the first embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic vertical cross-sectional view showing a state after assembly of a shaft of a rotor in the first embodiment of the present invention. [Figure 4]FIG. 4 is a vertical cross-sectional view showing an intermediate state between the state shown in FIG. 2 and the state shown in FIG. [Diagram 5] FIG. 5 is a perspective view of the cylindrical body of the first embodiment. [Figure 6] FIG. 6 is a vertical cross-sectional perspective view of the cylindrical body of the first embodiment. [Figure 7] FIG. 7 is a vertical cross-sectional view showing a state before assembly of a shaft of a rotor in a second embodiment of the present invention. [Figure 8] FIG. 8 is a vertical sectional view showing a state after assembly of a shaft of a rotor in a second embodiment of the present invention. [Figure 9] FIG. 9 is a perspective view of a cylindrical body according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotating electric machine and a drive device according to the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings. First Embodiment A first embodiment of a rotating electric machine and a drive device according to the present invention will be described with reference to Figs. 1 to 6. In the following description, a case in which the drive device of the embodiment is mounted on a vehicle positioned on a horizontal road surface is taken as an example. In addition, the central axis J shown in the drawings as appropriate is a virtual axis extending in a direction intersecting the vertical direction. In the following description, the direction parallel to the central axis J may be simply referred to as the "axial direction," the radial direction about the central axis J may be simply referred to as the "radial direction," and the circumferential direction about the central axis J (around the central axis J) may be simply referred to as the "circumferential direction."

[0010] Furthermore, in this specification, the terms "upper / lower direction," "horizontal direction," "upper side," and "lower side" are simply names used to describe the relative positional relationships of each part, and the actual positional relationships, etc. may be other than those indicated by these names. 2 to 8, the left side is referred to as the "upstream side" and the right side is referred to as the "downstream side." In the illustrated configuration, the "upstream side" corresponds to "one side in the axial (central axis J) direction" and the "downstream side" corresponds to "the other side in the axial (central axis J) direction."

[0011] A drive device 100 according to the present embodiment shown in Fig. 1 is a drive device mounted on a vehicle to rotate an axle 64. The vehicle on which the drive device 100 is mounted is a vehicle that uses a motor as a power source, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV). As shown in Fig. 1, the drive device 100 includes a rotating electric machine 10, a housing 80, a transmission device 60, and a refrigerant flow path 90. The rotating electric machine 10 includes a rotor 30 that is rotatable about a central axis (shaft) J, and a stator 40 that is positioned radially outward of the rotor 30.

[0012] The housing 80 accommodates the rotating electric machine 10 and the transmission device 60. The housing 80 has a motor housing 81 and a gear housing 82. The motor housing 81 is a housing that accommodates the rotor 30 and the stator 40 therein. The motor housing 81 is connected to the right side of the gear housing 82. The motor housing 81 has a peripheral wall portion 81a, a partition wall portion 81b, and a lid portion 81c. The peripheral wall portion 81a and the partition wall portion 81b are, for example, part of the same single member. The lid portion 81c is, for example, separate from the peripheral wall portion 81a and the partition wall portion 81b.

[0013] The peripheral wall portion 81a is cylindrical and surrounds the central axis J, opening to the right. The partition wall portion 81b is connected to the left end portion of the peripheral wall portion 81a. The partition wall portion 81b axially separates the interior of the motor housing 81 from the interior of the gear housing 82. The partition wall portion 81b has a partition wall opening 81d that connects the interior of the motor housing 81 to the interior of the gear housing 82. The partition wall portion 81b holds the bearing 34. The lid portion 81c is fixed to the right end portion of the peripheral wall portion 81a. The lid portion 81c closes the right opening of the peripheral wall portion 81a. The lid portion 81c holds the bearing 35.

[0014] The gear housing 82 accommodates therein the reduction gear 62 and the differential gear 63 of the transmission device 60, and oil O. The oil O is stored in a lower region within the gear housing 82. The oil O circulates within a refrigerant flow path 90. The oil O is used as a refrigerant that cools the rotating electric machine 10. The oil O is also used as a lubricant 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 an automatic transmission lubricant (ATF: Automatic Transmission Fluid) with a relatively low viscosity in order to function as a refrigerant and a lubricant.

[0015] The transmission device 60 is connected to the rotating electric machine 10 and transmits the rotation of the rotor 30 to an axle 64 of the vehicle. The transmission device 60 of this embodiment has a reduction gear 62 connected to the rotating electric machine 10 and a differential gear 63 connected to the reduction gear 62. The differential device 63 has a ring gear 63a. Torque output from the rotating electric machine 10 is transmitted to the ring gear 63a via the reduction gear 62. A lower end of the ring gear 63a is immersed in oil O stored in the gear housing 82. The oil O is scooped up as the ring gear 63a rotates. The scooped up oil O is supplied to the reduction gear 62 and the differential device 63, for example, as lubricating oil.

[0016] The rotating electric machine 10 is a part that drives the drive device 100. The rotating electric machine 10 is located, for example, on the right side of the transmission device 60. In this embodiment, the rotating electric machine 10 is a motor. The torque of a rotor 30 of the rotating electric machine 10 is transmitted to the transmission device 60. The rotor 30 has a shaft 1 that extends in the axial direction about a central axis J, and a rotor body 32 fixed to the shaft 1. The rotor body 32 is composed of, for example, a plurality of rotor core parts that are fixed to the outer circumferential surface of the shaft 1 and arranged in the axial direction, and magnets that are respectively held in each rotor core part.

[0017] As shown in FIG. 1, the shaft 1 is rotatable about a central axis J. This allows the rotor 30 to rotate about the shaft 1 as the center of rotation. The shaft 1 is rotatably supported by bearings 34 and 35. In this embodiment, the shaft 1 is a hollow shaft. The shaft 1 is cylindrical, through which oil O can flow as a refrigerant. The shaft 1 extends across the interior of the motor housing 81 and the interior of the gear housing 82. The left end of the shaft 1 protrudes into the interior of the gear housing 82. The reduction gear 62 is connected to the left end of the shaft 1.

[0018] The stator 40 is located radially outward from the rotor 30 with a gap therebetween. The stator 40 surrounds the rotor 30 from the radially outward over the entire circumferential direction. The stator 40 is fixed inside the motor housing 81. The stator 40 has a stator core 41 and a coil assembly 42.

[0019] The stator core 41 is annular and surrounds the central axis J of the rotating electric machine 10. The stator core 41 is formed by, for example, stacking a plurality of plate members such as electromagnetic steel sheets in the axial direction. 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 respectively attached to each tooth (not shown) of the stator core 41 via insulators (not shown). The plurality of coils 42c are arranged along the circumferential direction. The coils 42c have a portion that protrudes from the stator core 41 in the axial direction.

[0020] The refrigerant flow path 90 is provided in the housing 80. Oil O flows as a refrigerant in the refrigerant flow path 90. The refrigerant flow path 90 is provided across the interior of the motor housing 81 and the interior of the gear housing 82. The refrigerant flow path 90 is a path through which the oil O stored in the gear housing 82 is supplied to the rotating electric machine 10 in the motor housing 81 and returns to the gear housing 82 again. The refrigerant flow path 90 is provided with a pump 71 and a cooler 72. The refrigerant flow path 90 has a first flow path portion 91, a second flow path portion 92, a third flow path portion 93, a stator refrigerant supply portion 50, a shaft flow path portion 95, a connection flow path portion 94, a radial flow path portion 96, an axial flow path portion 98, and a guide flow path portion 97.

[0021] The first flow path portion 91, the second flow path portion 92, and the third flow path portion 93 are provided, for example, in a wall portion of the gear housing 82. The first flow path portion 91 connects the pump 71 to a portion of the interior of the gear housing 82 in which the oil O is stored. The second flow path portion 92 connects the pump 71 to the cooler 72. The third flow path portion 93 connects the cooler 72 to the stator coolant supply portion 50. In this embodiment, the third flow path portion 93 is connected to a left end portion of the stator coolant supply portion 50, i.e., an upstream portion of the stator coolant supply portion 50.

[0022] The stator refrigerant supply unit 50 supplies oil O to the stator 40. In this embodiment, the stator refrigerant supply unit 50 is tubular and extends in the axial direction. In other words, in this embodiment, the stator refrigerant supply unit 50 is a pipe extending in the axial direction. Both axial ends of the stator refrigerant supply unit 50 are supported by the motor housing 81. The left end of the stator refrigerant supply unit 50 is supported by, for example, the partition wall portion 81b. The right end of the stator refrigerant supply unit 50 is supported by, for example, the lid portion 81c. The stator refrigerant supply unit 50 is located radially outside the stator 40. In this embodiment, the stator refrigerant supply unit 50 is located above the stator 40.

[0023] The stator coolant supply unit 50 has a supply port 50a that supplies oil O to the stator 40. In this embodiment, the supply port 50a is an injection port that injects a portion of the oil O that has flowed into the stator coolant supply unit 50 to the outside of the stator coolant supply unit 50. The supply port 50a is configured as a hole that penetrates the wall of the stator coolant supply unit 50 from the inner circumferential surface to the outer circumferential surface. A plurality of supply ports 50a are provided in the stator coolant supply unit 50. The plurality of supply ports 50a are arranged, for example, at intervals from each other in the axial or circumferential direction.

[0024] The shaft flow passage portion 95 is disposed inside the shaft 1. This allows the oil O to be supplied into the shaft 1. Further, the connection flow passage portion 94 connects the inside of the stator coolant supply portion 50 and the inside of the shaft 1. The connection flow passage portion 94 connects the right end portion, i.e., the downstream portion, of the stator coolant supply portion 50 and the right end portion, i.e., the upstream portion, of the shaft flow passage portion 95. The connection flow passage portion 94 is provided in, for example, the lid portion 81c. According to this embodiment, the configuration of the coolant flow passage 90 can be simplified while stably cooling the stator 40 and the rotor 30. The axial flow passage portion 98 connects the radial flow passage portion 96 and the guide flow passage portion 97. The axial flow passage portion 98 is disposed across the interiors of the multiple rotor core portions.

[0025] As shown in FIG. 1, when the pump 71 is driven, the oil O stored in the gear housing 82 is sucked up through the first flow passage portion 91 and flows into the cooler 72 through the second flow passage portion 92. The oil O that flows into the cooler 72 is cooled in the cooler 72, and then flows into the stator coolant supply portion 50 through the third flow passage portion 93. A part of the oil O that flows into the stator coolant supply portion 50 is sprayed from the supply port 50a and supplied to the stator 40. Another part of the oil O that flows into the stator coolant supply portion 50 flows into the shaft flow passage portion 95 through the connection flow passage portion 94. A part of the oil O that flows through the shaft flow passage portion 95 flows from the coolant supply hole 33 through the radial flow passage portion 96, the axial flow passage portion 98, and the guide flow passage portion 97, and is scattered onto the stator 40. Another part of the oil O that flows into the shaft flow passage portion 95 is discharged into the inside of the gear housing 82 from the opening on the left side of the shaft 1, and is again stored in the gear housing 82.

[0026] The oil O supplied to the stator 40 from the supply port 50a removes heat from the stator 40, and the oil O supplied to the rotor 30 and the stator 40 from inside the shaft 1 removes heat from the rotor 30 and the stator 40. The oil O that has cooled the stator 40 and the rotor 30 drops downward and accumulates in a lower region inside the motor housing 81. The oil O that has accumulated in the lower region inside the motor housing 81 returns to inside the gear housing 82 through the partition wall opening 81d provided in the partition wall portion 81b. In this manner, the refrigerant flow path 90 supplies the oil O stored in the gear housing 82 to the rotor 30 and the stator 40.

[0027] As described above, the oil O can flow inside the shaft 1. When the rotor 30 rotates at a speed exceeding a predetermined rotational speed, the oil O is preferentially discharged from the refrigerant supply hole 33 due to centrifugal force. At this time, the flow of the oil O along the central axis J is not ensured downstream of the refrigerant supply hole 33 inside the shaft 1, and the cooling efficiency for the rotor 30 may decrease, or the amount of oil O supplied as lubricating oil to the bearings 35 may decrease. Therefore, the rotating electrical machine 10 is configured to be able to eliminate such problems. The configuration and operation of this configuration will be described below. 4 is a vertical cross-sectional view showing an intermediate state between the state shown in FIG. 2 (pre-assembly state) and the state shown in FIG. 3 (completed assembly state), and for convenience, the flow of oil O is illustrated.

[0028] As shown in FIGS. 2 and 3, the shaft 1 includes a shaft body 2 and a cylindrical body 5 that is inserted into the shaft body 2. The shaft body 2 is formed of a cylindrical member having a total length longer than that of the cylindrical body 5. As shown in FIG. 2, the shaft body 2 has a first side hole 22. The first side hole 22 is a through hole that penetrates the shaft body 2 in the radial direction. Also, a plurality of first side holes 22 are provided. The number of first side holes 22 arranged is four in this embodiment, but is not limited to this, and may be, for example, two, three, five or more. The four first side holes 22 are disposed at equal angular intervals around the central axis J and at the same position in the direction of the central axis J.

[0029] In addition, the shaft body 2 has a thin-walled portion 24, a thick-walled portion 25, and a tapered portion . The thin-walled portion 24 is located on the upstream side (one side in the direction of the central axis J) of the shaft body 2. Further, the thin-walled portion 24 is provided with a first side hole 22. The thick portion 25 is located downstream (the other side in the direction of the central axis J) of the thin portion 24. The thick portion 25 is a portion whose inner diameter is smaller than the inner diameter of the thin portion 24. The tapered portion 26 is located between the thin portion 24 and the thick portion 25. The tapered portion 26 is a portion where the inner diameter decreases from the thin portion 24 toward the thick portion 25. In this embodiment, among the thin portion 24, the thick portion 25, and the tapered portion 26, the thick portion 25 has the longest overall length, the thin portion 24 has the next longest overall length, and the tapered portion 26 has the shortest overall length.

[0030] A cylindrical body 5 is inserted into the upstream side of the shaft body 2 . 5 and 6, the cylinder 5 is formed with a plurality of slits 54 extending from the upstream end face 502 of the cylinder 5 along the central axis J. The number of slits 54 is three in this embodiment, but is not limited to this and may be, for example, two or four or more. The three slits 54 are disposed around the central axis J at equal angular intervals. The three slits 54 have the same overall length and width. The width of the three slits 54 is smaller than the diameter of the first side hole 22 of the shaft body 2. The upstream portion of the cylinder 5 is divided circumferentially by the three slits 54, thereby forming three plate-like portions 55. The three plate-like portions 55 are disposed adjacent to each other around the central axis J via the slits 54.

[0031] The cylindrical body 5 has a press-fit portion 56 provided downstream of each plate-like portion 55. As shown in Fig. 3, the press-fit portion 56 is press-fitted into the upstream end of the thick-walled portion 25 when the cylindrical body 5 is inserted into the shaft body 2. This allows the cylindrical body 5 to be fixed to the shaft body 2 and placed in an attached state (hereinafter referred to as the "attached state"). Furthermore, because the press-fit portion 56 is press-fitted into the thick-walled portion 25, the cylindrical body 5 is prevented from coming off the shaft body 2, and the attached state can be maintained.

[0032] In addition, in the attached state, the press-fitted portion 56 is pressed into the thick-walled portion 25, and thus undergoes slight contraction deformation radially inward. Due to this deformation, as shown in Fig. 3, the upstream side of each plate-like portion 55 expands radially outward and comes into contact with the thin-walled portion 24. This fixes the position of the cylindrical body 5 relative to the shaft main body 2, and together with the pressed-in state of the press-fitted portion 56, the attached state can be maintained for a long period of time. The higher the rotation speed of the rotor 30, the more each plate-like portion 55 spreads outward in the radial direction due to centrifugal force. This increases the force with which each plate-like portion 55 presses against the thin-walled portion 24, and the cylindrical body 5 is firmly fixed to the shaft body 2. This makes it possible to more reliably prevent the cylindrical body 5 from coming off the shaft body 2.

[0033] Here, the process of inserting the cylindrical body 5 into the shaft body 2 and assembling the shaft 1 will be described with reference to Figs. 2, the cylindrical body 5 is disposed upstream of the shaft body 2. At this time, the shaft body 2 and the cylindrical body 5 are disposed coaxially (on the central axis J). Next, the cylindrical body 5 is brought closer to the shaft main body 2, and insertion of the cylindrical body 5 begins. As the cylindrical body 5 is inserted into the shaft body 2, the press-fit portion 56 of the cylindrical body 5 passes through the thin-walled portion 24 and comes into contact with the tapered portion 26 (see FIG. 4).

[0034] Then, when the cylindrical body 5 is further inserted into the shaft body 2, the press-fit portion 56 passes over the tapered portion 26 and reaches the thick-walled portion 25. As a result, as shown in FIG 3, the press-fit portion 56 is pressed in, and the insertion of the cylindrical body 5 can be stopped. By going through the above-mentioned process, the shaft 1 in which the cylindrical body 5 is inserted into the shaft main body 2 is obtained. As described above, the tapered portion 26 is provided between the thin portion 24 and the thick portion 25. This allows the press-fit portion 56 to move smoothly from the thin portion 24 to the thick portion 25. 5 and 6, a corner 561 on the downstream side of the press-fit portion 56 is chamfered. This allows the press-fit portion 56 to be easily press-fitted into the thick-walled portion 25.

[0035] Additionally, the cylindrical body 5 has a second side hole 52 provided in the press-fit portion 56 . The second side hole 52 is a through hole that penetrates the cylindrical body 5 in the radial direction (wall thickness direction). Also, a plurality of second side holes 52 are provided. In this embodiment, the number of second side holes 52 is eight, which is twice the number of first side holes 22, but is not limited to this and may be, for example, two to seven, or nine or more. The eight second side holes 52 are disposed at equal angular intervals around the central axis J and at the same position in the direction of the central axis J.

[0036] As shown in Fig. 4 (as well as Fig. 3), in the shaft 1, the inside of the cylinder 5 and each of the first side holes 22 are connected via the slits 54 and between each of the plate-like portions 55 and the shaft body 2. This ensures a flow path 12 through which the oil O can pass. The flow path 12 is a refrigerant supply hole 33. The oil O that has flowed into the shaft 1 includes oil O1 that passes over the slits 54 and flows directly downstream, and oil O2 that flows through each slit 54 and flows into the flow passage 12. When the rotor 30 rotates in this state at a speed exceeding a predetermined number of revolutions, the oil O is likely to be preferentially discharged from each slit 54 due to centrifugal force.

[0037] However, because the width of each slit 54 is smaller than the diameter of the first side hole 22, the flow of oil O2 toward the flow path 12 is suppressed. Then, the flow of oil O1 can be sufficiently secured by the amount of the suppressed flow of oil O2. As a result, regardless of the rotation speed of the rotor 30, the cooling efficiency of the stator 40 by the oil O2 can be improved, and the cooling efficiency of the rotor 30 by the oil O1 can also be sufficiently improved. In addition, the oil O1 can be made to function sufficiently as a lubricating oil for the bearings 35.

[0038] 4, when the shaft 1 in the attached state is viewed from the radial direction (side view), one first side hole 22 overlaps one slit 54. This allows the oil O to pass smoothly from the inside of the cylindrical body 5 to each first side hole 22, and prevents the flow of the oil O2 from being excessively restricted as described above. When the shaft 1 in the attached state is viewed from the radial direction, two or more corresponding first side holes 22 and slits 54 may overlap, or they may not all overlap and may be misaligned.

[0039] In the attached state, the multiple second side holes 52 are located downstream of the multiple first side holes 22. Even if some oil O cannot be discharged from the first side holes 22 to the radial flow paths 96 depending on the flow rate of the oil O supplied to the shaft 1, the oil O can be returned from the inside of the cylinder 5 to the inside of the cylinder 5 through the slits 54, between each plate-like portion 55 and the shaft main body 2, and through the second side holes 52 in this order. This makes it possible to replenish the oil O returned to the inside of the cylinder 5 as oil O1. The material from which the shaft body 2 and the cylindrical body 5 are made is not particularly limited, and may be, for example, a hard material such as a metal material or a resin material.

[0040] <Second embodiment> A rotating electric machine and a drive device according to a second embodiment of the present invention will be described below with reference to Figs. 7 to 9. The description will focus on the differences from the previously described embodiment, and descriptions of similar points will be omitted. 7 and 8, the inside diameter of the shaft body 2 is constant along the direction of the central axis J. That is, the shaft body 2 is a member in which the thick-walled portion 25 and the tapered portion 26 are omitted. The shaft body 2 also has a recess 27 provided on its inner circumferential surface. The recess 27 is provided in a ring shape along the circumferential direction of the shaft body 2. The recess 27 is located upstream of each of the first side holes 22.

[0041] On the other hand, as shown in Figs. 7 to 9, in the cylindrical body 5 of the second embodiment, the upstream end of each plate-like portion 55 is provided with a convex portion (flange portion) 551 that protrudes radially outward. 8, in the attached state, each convex portion 551 of the cylindrical body 5 is inserted into each concave portion 27. This regulates the position of the cylindrical body 5 relative to the shaft body 2. In addition, the cylindrical body 5 is prevented from coming off the shaft body 2, and the attached state can be maintained. When inserting the cylindrical body 5 into the shaft main body 2, each plate-like portion 55 of the cylindrical body 5 is moved toward the central axis J to reduce the diameter of the cylindrical body 5 as a whole, as shown in Fig. 7. This prevents the protrusions 551 of each plate-like portion 55 from interfering with the insertion of the cylindrical body 5, enabling smooth insertion.

[0042] Although the rotating electric machine and the drive device of the present invention have been described above with reference to the illustrated embodiment, the present invention is not limited thereto, and each part constituting the rotating electric machine and the drive device may be replaced with any other component capable of exerting the same function. Also, any other component may be added. Furthermore, the rotating electric machine and drive device of the present invention may be a combination of any two or more of the configurations (features) of the above-described embodiments. Furthermore, multiple types of cylinders 5 having different arrangement positions or numbers of the second side holes 52 in the direction of the central axis J may be prepared in advance. In this case, an appropriate cylinder 5 can be selected from the multiple types of cylinders 5 and attached to the shaft body 2 depending on various conditions such as the type of rotating electric machine 10 on which the shaft 1 is mounted.

[0043] Furthermore, although the cylindrical body 5 is composed of a single continuous member, this is not limited thereto, and for example, the cylindrical body 5 may be composed of a divided body divided into at least two parts along the direction of the central axis J. In addition, any of the configurations of the first and second embodiments may be combined. For example, a convex portion 551 may be provided at the upstream end of each plate-like portion 55 of the cylinder 5 of the first embodiment. In this case, the convex portion 551 of each plate-like portion 55 may be configured to be inserted into the concave portion 27 provided on the inner circumferential surface of the shaft body 2 when the cylinder 5 is inserted into the shaft body 2, as in the second embodiment, or may be configured to come into contact with the upstream end face 202 of the shaft body 2. [Explanation of symbols]

[0044] 1 Shaft 2 Shaft body 202 End face 22 1st side hole 24 Thin section 25 Thick wall part 26 Tapered section 27 Recess 5. Cylinder 502 End face 52 2nd side hole 54 Slit 55 Plate-shaped part 551 Convex 56 Press-fit part 561 Corner 10 Rotating Electric Machine 12 Flow Path 30 rotors 32 Rotor body 33 Coolant supply hole 34 Bearings 35 Bearings 40 Stator 41 Stator core 42 Coil Assembly 42c coil 50 Stator coolant supply section 50a Supply port 60 Transmission Device 62 Reducer 63 Differential device 63a Ring gear 64 Axles 71 Pump 72 Cooler 80 Housing 81 Motor housing 81a Peripheral wall part 81b Bulkhead 81c Lid 81d Bulkhead opening 82 Gear housing 90 Coolant flow path 91 First flow path section 92 Second flow path section 93 Third flow path section 94 Connection flow path 95 Shaft passage 96 Radial flow passage 97 Guide passage section 98 Axial flow passage 100 Drive unit J Center axis (axis) O Oil O1 Oil O2 Oil

Claims

1. a rotor having a shaft through which a refrigerant can flow and rotatable about the shaft; a stator positioned radially outward of the rotor, The shaft is a cylindrical shaft body having a plurality of first side holes extending radially therethrough; a cylindrical body that is inserted into one axial side of the shaft body, the cylindrical body having a plurality of plate-like portions provided on the one axial side and arranged adjacent to each other around the axis with slits interposed therebetween; In a state where the cylindrical body is attached to the shaft body, one axial side of each of the plate-like portions contacts the shaft body, and an inside of the cylindrical body and each of the first side holes are connected via the slit and between each of the plate-like portions and the shaft body, thereby functioning as a flow path through which the refrigerant can pass, the shaft body has a thin-walled portion located on one axial side thereof and including each of the first side holes, and a thick-walled portion located on the other axial side of the thin-walled portion and having an inner diameter smaller than the inner diameter of the thin-walled portion, The cylindrical body further includes a press-fit portion provided on the other axial side of each of the plate-like portions and press-fitted into an end portion on one axial side of the thick-walled portion, A rotating electric machine in which the press-fit portion is press-fitted into the thick-walled portion, so that in the attached state, one axial side of each of the plate-like portions expands radially outward and contacts the thin-walled portion.

2. The shaft body further includes a thin wall portion and a thick wall portion, the thin wall portion being located between the thin wall portion and the thick wall portion, and the inner diameter of the thin wall portion being larger than the inner diameter of the thick wall portion.

2. The rotating electric machine according to claim 1, further comprising a tapered portion that decreases from the wall portion toward the thick wall portion.

3. 3. The rotating electric machine according to claim 2, wherein a corner of an end portion on the other axial end side of the press-fit portion is chamfered.

4. The shaft body further has a recess provided on an inner circumferential surface on one axial side of each of the first side holes, 2 . The rotating electric machine according to claim 1 , wherein the cylindrical body has a protrusion provided at one axial end of each of the plate-like portions, the protrusion being inserted into the recess in the attached state.

5. In the attached state, when viewed from a radial direction, the first side hole and the slit overlap with each other. The rotating electric machine according to any one of claims 1 to 4.

6. The cylindrical body further has a plurality of second side holes penetrating in a radial direction, and in the attached state, The second side holes are located on the other axial end side of the first side holes. The rotating electric machine according to any one of claims 1 to 5.

7. A drive device mounted on a vehicle to rotate an axle, A rotating electric machine according to any one of claims 1 to 6, a transmission device connected to the rotating electric machine and configured to transmit rotation of the rotor to the axle; a housing that accommodates the rotating electric machine and the transmission device; a coolant passage provided within the housing for supplying a coolant to the inside of the shaft and the stator of the rotating electric machine.

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