WO2018030324A1

WO2018030324A1 - Drive device

Info

Publication number: WO2018030324A1
Application number: PCT/JP2017/028551
Authority: WO
Inventors: 山口　康夫; 勇樹石川
Original assignee: 日本電産株式会社
Priority date: 2016-08-09
Filing date: 2017-08-07
Publication date: 2018-02-15

Abstract

One embodiment of this drive device comprises: a rotor; a stator; a housing that has a housing part that can store oil; a pump part that is driven via a motor shaft; and a transmission member that transmits the rotation of the motor shaft to a pump shaft. The pump part has: an external gear that is fixed to the pump shaft; an internal gear that surrounds the external gear and that meshes with the external gear; a pump chamber that is provided to the housing and that houses the internal gear and the external gear; an intake port that can take oil into the pump chamber; and a discharge port that can discharge oil from the pump chamber. The housing has a first oil passage that connects to the discharge port. The motor shaft has: a second oil passage that is provided inside the motor shaft and that connects to the first oil passage; and a first through hole that connects the second oil passage and an outer circumferential surface of the motor shaft. The intake port opens at a vertical direction lower region of the housing part and can take oil that is stored in the housing part into the pump chamber.

Description

Drive device

The present invention relates to a drive device.

2. Description of the Related Art A rotating electric machine is known that includes a case for storing a lubricating fluid for lubrication and cooling such as a stator and a rotor. For example, Patent Document 1 describes a rotating electrical machine mounted on a vehicle.

JP 2013-055728 A

The rotating electrical machine as described above may be provided with a pump unit that sucks up oil stored in the case. The rotor and the stator can be cooled by sucking up the oil by the pump unit and supplying the oil to the rotor and the stator, for example. However, when the pump unit is simply provided in the rotating electrical machine, it is necessary to provide an oil passage through which oil flows, and thus the structure of the rotating electrical machine is likely to be complicated, and the rotating electrical machine may be increased in size. *

In view of the above circumstances, an object of the present invention is to provide a drive device having a structure that can be miniaturized while being provided with a pump unit capable of sending oil stored in a housing.

One aspect of the drive device according to the present invention includes a rotor having a motor shaft disposed along a central axis extending in one direction, a stator facing the rotor via a gap in a radial direction, the rotor, and the stator A housing having a housing portion that can store oil and a pump shaft that is disposed along an axis different from the central axis in the housing and is driven via the motor shaft; A transmission member that transmits the rotation of the motor shaft to the pump shaft, and the pump portion surrounds the external gear and is meshed with the external gear that is fixed to the pump shaft. An internal gear, a pump chamber provided in the housing and containing the internal gear and the external gear, and oil in the pump chamber A suction port that can be inserted, and a discharge port that can discharge oil from the pump chamber, wherein the housing has a first oil passage connected to the discharge port, and the motor shaft is connected to the motor shaft. A second oil passage provided inside and connected to the first oil passage; and a first through hole connecting the second oil passage and an outer peripheral surface of the motor shaft; The oil is opened in a region on the lower side in the vertical direction of the portion, and oil stored in the housing portion can be sucked into the pump chamber.

According to one aspect of the present invention, there is provided a drive device having a structure that can be miniaturized while being provided with a pump unit capable of sending oil stored in a housing.

FIG. 1 is a cross-sectional view showing the drive device of the present embodiment. FIG. 2 is a view of the pump unit of this embodiment as viewed from the other side in the axial direction. FIG. 3 is a cross-sectional view showing a part of the driving apparatus of the present embodiment.

The Z-axis direction shown in each figure is a vertical direction Z in which the positive side is the upper side and the negative side is the lower side. In the present embodiment, the vertical direction Z is the vertical direction of each figure. In the following description, the upper side in the vertical direction is simply referred to as “upper side”, and the lower side in the vertical direction is simply referred to as “lower side”. *

As shown in FIG. 1, the drive device 1 according to the present embodiment includes a housing 10, a rotor 20 having a motor shaft 21 disposed along a central axis J <b> 1 extending in one direction, a rotation detection unit 80, and a stator 30. A pump unit 40, a transmission member 50, and

bearings

70 and 71. *

The central axis J1 extends in the left-right direction in FIG. That is, in the present embodiment, the left-right direction in FIG. 1 corresponds to one direction. In the following description, a direction parallel to the axial direction of the central axis J1 is simply referred to as “axial direction”, a radial direction centered on the central axis J1 is simply referred to as “radial direction”, and the central axis J1 is the center. The circumferential direction is simply called “circumferential direction”. Further, the left side of FIG. 1 in the axial direction is referred to as “one axial side”, and the right side of FIG. 1 in the axial direction is referred to as “the other axial side”. *

The housing 10 includes a main body portion 11, a first portion 12, and a second portion 13. In the present embodiment, the main body 11, the first portion 12, and the second portion 13 are separate members. The main body 11 has a bottomed cylindrical shape that opens to one side in the axial direction. The main body part 11 includes a bottom part 11a, a main body cylinder part 11b, and a bearing holding part 11c. The bottom portion 11a has an annular plate shape that expands in the radial direction. The main body cylinder portion 11b has a cylindrical shape extending from the radially outer edge portion of the bottom portion 11a to one side in the axial direction. The bearing holding portion 11c has a cylindrical shape protruding from the inner edge portion of the bottom portion 11a to one side in the axial direction. The bearing holding portion 11c holds the bearing 71 on the inner side. *

The first portion 12 is a covered cylinder that opens to the other side in the axial direction. The first portion 12 is attached to one side of the main body portion 11 in the axial direction. The first portion 12 includes a lid portion 12a, a first cylinder portion 12b, and a bearing holding portion 12c. The lid portion 12a has an annular plate shape that expands in the radial direction. The lid portion 12 a covers one side of the stator 30 in the axial direction. That is, the first portion 12 covers one side of the stator 30 in the axial direction. An opening 12f that penetrates the lid 12a in the axial direction is provided at the lower end of the lid 12a. That is, the first portion 12 has an opening 12 f that penetrates the first portion 12 in the axial direction. *

The 1st cylinder part 12b is a cylindrical shape extended from the radial direction outer edge part of the cover part 12a to the other side of an axial direction. The end portion on the other axial side of the first cylindrical portion 12b is fixed in contact with the end portion on the one axial side of the main body cylindrical portion 11b. The bearing holding portion 12c has a cylindrical shape protruding from the inner edge portion of the lid portion 12a to the other side in the axial direction. The bearing holding portion 12c holds the bearing 70 on the inner side. That is, the first portion 12 holds the bearing 70. *

The main body 11 and the first portion 12 are fixed to each other, whereby the accommodating portion 14 surrounded by the main body 11 and the first portion 12 is configured. That is, the housing 10 has the accommodating portion 14. The accommodating portion 14 accommodates the rotor 20 and the stator 30 and can store the oil O. The oil O is stored in the lower region of the accommodating portion 14. In this specification, the “region below the storage portion” includes a portion located below the center in the vertical direction Z of the storage portion. *

In the present embodiment, the liquid surface OS of the oil O stored in the storage unit 14 is located above the opening 12f. The liquid surface OS of the oil O fluctuates as the oil O is sucked up by the pump unit 40, but is disposed below the rotor 20 at least when the rotor 20 rotates. Thereby, when the rotor 20 rotates, it can suppress that the oil O becomes rotational resistance of the rotor 20. FIG. *

The second portion 13 is attached to one side of the first portion 12 in the axial direction. The second portion 13 has a recess 13 a that is recessed from the surface on the other axial side of the second portion 13 to the one axial side. The recess 13a overlaps the bearing holding portion 12c in the axial direction. The recess 13a is closed by the surface on the one axial side of the first portion 12, that is, the surface on the one axial side of the lid 12a. As a result, a space 13b surrounded by the inner side surface of the recess 13a and the surface on the one axial side of the first portion 12 is formed. The central axis J1 passes through the space 13b. *

A pump chamber 46 is provided in the second portion 13. That is, the pump chamber 46 is provided in the housing 10. The pump chamber 46 is recessed from the surface on the other axial side of the second portion 13 to the one axial side. More specifically, the pump chamber 46 is recessed from the surface on the other axial side at the lower end of the second portion 13 to the one axial side. As shown in FIG. 2, the outer shape of the pump chamber 46 viewed along the axial direction is circular. The pump chamber 46 accommodates an internal gear 43 and an external gear 42 which will be described later. *

As shown in FIG. 1, the upper portion of the opening on the other axial side of the pump chamber 46 is closed by the end surface on the one axial side of the lid 12 a. That is, the first portion 12 has a closing portion 12 d that closes a part of the opening on the other axial side of the pump chamber 46. In the present embodiment, the closing part 12d is a part of the lower part of the lid part 12a. The closing part 12d has a sliding bearing part 12e penetrating the closing part 12d in the axial direction. The sliding bearing portion 12e is located between the pump chamber 46 and the accommodating portion 14 in the axial direction. One end of the sliding bearing portion 12 e in the axial direction opens into the pump chamber 46. The end portion on the other side in the axial direction of the sliding bearing portion 12 e opens into the accommodating portion 14. At least a part of the sliding bearing portion 12e is disposed below the liquid surface OS of the oil O stored in the storage portion 14. In FIG. 1, the lower portion of the sliding bearing portion 12 e is disposed below the liquid level OS. As shown in FIG. 2, the outer shape of the plain bearing portion 12e viewed along the axial direction is circular. In this embodiment, the slide bearing portion is the same member as the first portion 12, but the first portion 12 has a slide bearing support portion that supports the slide bearing, and is held by a slide bearing member such as a sintered oil-impregnated bearing. May be. *

The lower end of the pump chamber 46 overlaps the opening 12f in the axial direction. Thereby, the lower end part of the pump chamber 46 faces the accommodating part 14 through the opening part 12f. A lower end portion of the pump chamber 46 facing the accommodating portion 14 is a suction port 44. That is, the opening portion 12 f exposes the suction port 44 to the housing portion 14. In the present embodiment, the second portion 13 is a separate member from the first portion 12, and thus it is easy to configure the pump chamber 46. *

As shown in FIG. 1, the housing 10 includes a first oil passage 61 and a third oil passage 63. In the present embodiment, the first oil passage 61 is provided in the second portion 13. The first oil passage 61 extends in the vertical direction Z. The first oil passage 61 extends from the position overlapping the upper end of the pump chamber 46 in the axial direction to the upper side of the central axis J1. The first oil passage 61 is disposed on one axial side of the recess 13a. The first oil passage 61 is connected to the space 13b through the connection hole 61a. The connection hole 61a is, for example, a circular hole centered on the central axis J1. The lower end portion of the first oil passage 61 is connected to the upper end portion of the pump chamber 46 from one side in the axial direction. A portion where the first oil passage 61 is connected in the pump chamber 46 is a discharge port 45. That is, the first oil passage 61 is connected to the discharge port 45. *

The third oil passage 63 is provided across the second portion 13, the first portion 12, and the main body portion 11. As shown in FIGS. 1 and 3, the third oil passage 63 includes a first extending portion 63a, a second extending portion 63b, a third extending portion 63e, a fourth extending portion 63f, and

supply portions

63c and 63d. And having. *

As shown in FIG. 1, the first extending portion 63 a extends in the vertical direction Z from the upper end portion of the first oil passage 61. As a result, the third oil passage 63 is connected to the first oil passage 61. The upper end portion of the first extending portion 63 a is located at the upper end portion of the second portion 13. The second extending portion 63b extends from the upper end portion of the first extending portion 63a to the other side in the axial direction. The end of the second extending portion 63b on the other side in the axial direction is located on the lid portion 12a. The third extending portion 63e extends upward from the other axial end of the second extending portion 63b. The upper end portion of the third extending portion 63e is located at the upper end portion of the lid portion 12a. The fourth extending portion 63f extends from the upper end portion of the third extending portion 63e to the other side in the axial direction. The fourth extending part 63f is provided across the first cylinder part 12b and the main body cylinder part 11b from the lid part 12a. The fourth extending portion 63 f extends to the other side in the axial direction from the stator core 31.

As shown in FIG. 3, the

supply parts

63c and 63d extend downward from the fourth extending part 63f. The

supply parts

63c and 63d are provided in the main body cylinder part 11b. The

supply parts

63c and 63d open on the inner peripheral surface of the main body cylinder part 11b. Thereby, the

supply parts

63c and 63d open to the accommodating part 14. The supply part 63 c is disposed on one axial side of the stator core 31. The supply portion 63d is disposed on the other side in the axial direction than the stator core 31. The

supply parts

63c and 63d are opposed to each other on the upper side of the coil 32 via a gap in the radial direction. That is, the third oil passage 63 opens into the accommodating portion 14 on the upper side of the stator 30. The supply part 63d extends inward in the radial direction from the other axial end of the second extending part 63b. *

In this embodiment, the 3rd oil path 63 is provided ranging over the 2nd part 13, the 1st part 12, and the main-body part 11 which are another members, The 1st extending | stretching part which comprises the 3rd oil path 63 is provided. It is easy to process oil passages such as 63a and the second extending portion 63b. *

As shown in FIG. 1, the rotor 20 includes a motor shaft 21, a rotor core 22, a magnet 23, a first end plate 24, and a second end plate 25. The motor shaft 21 has a cylindrical shape extending in the axial direction. The motor shaft 21 has a large diameter portion 21a, a small diameter portion 21b, and an output portion 21e. *

The large diameter portion 21a is a portion to which the rotor core 22 is attached. The end portion on the other side in the axial direction of the large diameter portion 21 a is rotatably supported by the bearing 71. The small diameter portion 21b is connected to the large diameter portion 21a on one axial side of the large diameter portion 21a. An end portion on one side in the axial direction of the small diameter portion 21 b is an end portion on one side in the axial direction of the motor shaft 21. One end of the small diameter portion 21b in the axial direction is inserted into the space 13b. The outer diameter of the small diameter portion 21b is smaller than the outer diameter of the large diameter portion 21a. The end portion on the other side in the axial direction of the small diameter portion 21 b is rotatably supported by the bearing 70. The

bearings

70 and 71 rotatably support the motor shaft 21. The

bearings

70 and 71 are ball bearings, for example. *

The output part 21e is connected to the large diameter part 21a on the other axial side of the large diameter part 21a. The output portion 21e is an end portion on the other axial side of the motor shaft 21. The outer diameter of the output part 21e is smaller than the outer diameter of the large diameter part 21a and the outer diameter of the small diameter part 21b. The output portion 21e protrudes outside the housing 10 through the bottom portion 11a in the axial direction. *

The motor shaft 21 has a flange portion 21d. The flange portion 21d protrudes radially outward from the outer peripheral surface of the large diameter portion 21a. The flange portion 21d has an annular plate shape that is provided over the entire circumference of the outer peripheral surface of the large-diameter portion 21a. The flange portion 21d is provided at a portion closer to the other side in the axial direction of the large diameter portion 21a. A male screw portion is provided on the outer peripheral surface of the large diameter portion 21a near the one side in the axial direction. A nut 90 is fastened to the male screw portion of the large diameter portion 21a. *

The motor shaft 21 has a second oil passage 62 provided inside the motor shaft 21. The second oil passage 62 is a bottomed hole that extends from the end on one axial side of the motor shaft 21 to the other axial side. The second oil passage 62 extends from an end portion on one axial side of the small diameter portion 21b to an end portion on the other axial side of the large diameter portion 21a. In the present embodiment, the inner peripheral surface of the second oil passage 62 has a cylindrical shape centered on the central axis J1. The second oil passage 62 opens on one side in the axial direction. The end of the second oil passage 62 on one side in the axial direction opposes the connecting hole 61a in the axial direction. The second oil passage 62 is connected to the first oil passage 61 via the connection hole 61a. *

The motor shaft 21 has a first through hole 26 a that connects the second oil passage 62 and the outer peripheral surface of the motor shaft 21. The first through hole 26a extends in the radial direction. The first through hole 26a is provided in the large diameter portion 21a. Although illustration is omitted, a plurality of first through holes 26a are provided along the circumferential direction, for example. *

The rotor core 22 has an annular shape that is fitted to the motor shaft 21. The rotor core 22 has a rotor through hole 22a that penetrates the rotor core 22 in the axial direction and a magnet insertion hole 22b that penetrates the rotor core 22 in the axial direction. The rotor through hole 22a is disposed on the radially inner side than the magnet insertion hole 22b. A plurality of magnet insertion holes 22b are provided along the circumferential direction. The magnet 23 is inserted into the magnet insertion hole 22b. *

The first end plate 24 and the second end plate 25 have an annular plate shape that expands in the radial direction. A large diameter portion 21 a is passed through the first end plate 24 and the second end plate 25. The first end plate 24 and the second end plate 25 sandwich the rotor core 22 in the axial direction while being in contact with the rotor core 22. *

As shown in FIG. 3, the first end plate 24 is disposed on one axial side of the rotor core 22. The radially outer edge portion of the first end plate 24 is curved toward the other side in the axial direction, and contacts the radially outer edge portion of the surface on the one axial direction side of the rotor core 22. The radially outer edge of the first end plate 24 overlaps with the opening on one axial side of the magnet insertion hole 22b in the axial direction, and presses the magnet 23 inserted into the magnet insertion hole 22b from one axial side. A portion radially inward from the radially outer edge portion of the first end plate 24 faces the surface on one side in the axial direction of the rotor core 22 in the axial direction through a gap 27a. An end portion on the radially outer side of the first through hole 26a opens in the gap 27a. The first end plate 24 has an ejection hole 24 a that penetrates the first end plate 24 in the axial direction. The ejection hole 24 a is disposed radially inward of the rotor through hole 22 a and radially outward of the nut 90. *

The second end plate 25 is disposed on the other axial side of the rotor core 22. The radially outer edge portion of the second end plate 25 is curved in one axial direction, and contacts the radially outer edge portion of the surface on the other axial side of the rotor core 22. The radially outer edge of the second end plate 25 overlaps the opening on the other axial side of the magnet insertion hole 22b in the axial direction, and presses the magnet 23 inserted into the magnet insertion hole 22b from the other axial side. Thereby, the magnet 23 inserted into the magnet insertion hole 22b is pressed by the first end plate 24 and the second end plate 25 on both sides in the axial direction. Therefore, the magnet 23 can be prevented from coming out of the magnet insertion hole 22b. *

The radially inner portion of the second end plate 25 is radially opposed to the surface on the other axial side of the rotor core 22 via the gap 27b. The gap 27b is connected to the axial gap 27a between the first end plate 24 and the rotor core 22 via the rotor through hole 22a. The second end plate 25 has an ejection hole 25a penetrating the second end plate 25 in the axial direction. The ejection hole 25a is disposed radially inward of the rotor through hole 22a and radially outward of the flange portion 21d. The radial position of the ejection hole 25a is, for example, the same as the radial position of the ejection hole 24a. *

The first end plate 24, the rotor core 22, and the second end plate 25 are sandwiched in the axial direction by the nut 90 and the flange portion 21d. When the nut 90 is tightened into the male screw portion of the large diameter portion 21a, the nut 90 presses the first end plate 24, the rotor core 22, and the second end plate 25 against the flange portion 21d. Thereby, the 1st end plate 24, the rotor core 22, and the 2nd end plate 25 are fixed with respect to the large diameter part 21a. *

The rotation detector 80 shown in FIG. 1 detects the rotation of the rotor 20. In the present embodiment, the rotation detection unit 80 is, for example, a VR (Variable Reluctance) type resolver. The rotation detector 80 is disposed in the space 13b. The rotation detection unit 80 includes a detected unit 81 and a sensor unit 82. The detected part 81 has an annular shape extending in the circumferential direction. The detected part 81 is fitted and fixed to the small diameter part 21b. More specifically, the detected portion 81 is fitted and fixed to a portion where the outer diameter of the step portion whose outer diameter decreases from the other axial side to the one axial side provided in the small diameter portion 21b. Is done. The detected part 81 is made of a magnetic material. *

The sensor part 82 is fixed to the surface on one side in the axial direction of the lid part 12a. The sensor unit 82 has an annular shape that surrounds the radially outer side of the detected portion 81. The sensor unit 82 has a plurality of coils along the circumferential direction. When the detected part 81 rotates together with the motor shaft 21, an induced voltage corresponding to the circumferential position of the detected part 81 is generated in the coil of the sensor part 82. The sensor unit 82 detects the rotation of the detected unit 81 by detecting the induced voltage. Accordingly, the rotation detection unit 80 detects the rotation of the motor shaft 21 and detects the rotation of the rotor 20. *

The stator 30 faces the rotor 20 via a gap in the radial direction. The stator 30 includes a stator core 31 and a plurality of coils 32 attached to the stator core 31. The stator core 31 has an annular shape centered on the central axis J1. The outer peripheral surface of the stator core 31 is fixed to the inner peripheral surface of the main body cylinder portion 11b. The stator core 31 is opposed to the outer side in the radial direction of the rotor core 22 via a gap. *

The pump unit 40 is disposed at the lower end of the second portion 13. The pump unit 40 includes a pump shaft 41, an external gear 42, an internal gear 43, the above-described pump chamber 46, a suction port 44, and a discharge port 45. The pump shaft 41 is disposed in the housing 10 along a pump axis J2 that is an axis different from the central axis J1. In the present embodiment, the pump shaft J2 is parallel to the central axis J1. That is, the pump shaft 41 extends in the axial direction of the motor shaft 21. The pump shaft J2 is located below the center axis J1. *

The pump shaft 41 is disposed below the motor shaft 21 on one axial side of the stator 30. Therefore, by arranging the motor shaft 21 and the pump shaft 41 at a position at least partially overlapping in a direction orthogonal to the axial direction, the drive device 1 can be compared with the case where the motor shaft 21 and the pump shaft 41 are coaxial. It is easy to reduce the size in the axial direction. In FIG. 1, the motor shaft 21 and the pump shaft 41 overlap in the vertical direction Z. In the present embodiment, the pump chamber 46 and the first oil passage 61 are provided in the second portion 13 as described above. Thereby, the pump part 40 can be concentrated and arrange | positioned to the axial direction one side rather than the stator 30, and it is easy to make the drive device 1 smaller in an axial direction. In addition, since the pump shaft 41 extends in the axial direction of the motor shaft 21, it is easier to reduce the size of the drive device 1 in the radial direction than when the pump shaft 41 is inclined with respect to the motor shaft 21. *

The pump shaft 41 is disposed in the accommodating portion 14. One end of the pump shaft 41 in the axial direction is inserted into the pump chamber 46 via the plain bearing portion 12e. The portion of the pump shaft 41 that is inserted into the sliding bearing portion 12e is supported by the sliding bearing portion 12e. As a result, the pump shaft 41 is rotatably supported around the pump shaft J2 by the sliding bearing portion 12e. Thus, according to this embodiment, the pump shaft 41 can be supported with a simple configuration. *

Further, as described above, in the present embodiment, at least a part of the sliding bearing portion 12e is disposed below the liquid surface OS of the oil O. Therefore, the oil O flows between the sliding bearing portion 12e and the pump shaft 41. Thereby, the oil O can be used as lubricating oil for the sliding bearing portion 12e, and the pump shaft 41 can be suitably rotatably supported by the sliding bearing portion 12e. *

The external gear 42 is a gear that can rotate around the pump shaft J2. The external gear 42 is fixed to the end portion on the one axial side of the pump shaft 41 and is accommodated in the pump chamber 46. As shown in FIG. 2, the external gear 42 has a plurality of tooth portions 42a on the outer peripheral surface. The tooth profile of the tooth portion 42a of the external gear 42 is a trochoidal tooth profile. *

The internal gear 43 is an annular gear that is rotatable around a rotation axis J3 that is eccentric with respect to the pump shaft J2. The internal gear 43 is accommodated in the pump chamber 46. Internal gear 4
3 surrounds the external gear 42 and meshes with the external gear 42. The internal gear 43 has a plurality of tooth portions 43a on the inner peripheral surface. The tooth profile of the tooth portion 43a of the internal gear 43 is a trochoidal tooth profile. Thus, since the tooth profile of the tooth portion 42a of the external gear 42 and the tooth profile of the tooth portion 43a of the internal gear 43 are trochoidal tooth profiles, a trochoid pump can be configured. Therefore, noise generated from the pump unit 40 can be reduced, and the pressure and amount of the oil O discharged from the pump unit 40 can be easily stabilized.

As described above, the suction port 44 is a portion of the pump chamber 46 that is exposed in the accommodating portion 14 through the opening 12f. In the present embodiment, the suction port 44 has an arcuate shape that protrudes downward. The suction port 44 opens to a lower region of the storage portion 14 and can suck oil O stored in the storage portion 14 into the pump chamber 46. In the present embodiment, the suction port 44 is disposed below the rotor 20. At least a part of the suction port 44 is disposed below the liquid level OS of the oil O stored in the storage unit 14. In FIG. 1, the entire suction port 44 is disposed below the liquid level OS of the oil O. As shown in FIG. 1, in the present embodiment, the suction port 44 opens at the lower end of the accommodating portion 14. As described above, the discharge port 45 is a portion that opens to the first oil passage 61 in the pump chamber 46. The discharge port 45 opens to one axial side of the pump chamber 46. The discharge port 45 can discharge the oil O from the pump chamber 46. *

The transmission member 50 includes a first gear 51 and a second gear 52. The first gear 51 is a disc-shaped gear that can rotate around an axis parallel to the axial direction. The first gear 51 is fixed to the end portion on one axial side of the large diameter portion 21a. More specifically, the first gear 51 has an outer diameter of the step portion 21f provided at the end portion on the one axial side of the large diameter portion 21a so that the outer diameter decreases from the other axial side toward the one axial side. It is fixed by being fitted to the smaller part. The first gear 51 rotates around the central axis J1 together with the motor shaft 21. The first gear 51 is sandwiched between the bearing 70 and the stepped surface facing the left of the stepped portion of the large diameter portion 21a. *

The second gear 52 is a disk-shaped gear that can rotate around an axis parallel to the axial direction. The second gear 52 meshes with the first gear 51 on the lower side of the first gear 51. The second gear 52 is fixed to the end portion on the other axial side of the pump shaft 41. The second gear 52 rotates around the pump axis J2 together with the pump shaft 41. When the first gear 51 rotates along with the rotation of the motor shaft 21, the second gear 52 that meshes with the first gear 51 rotates, and the pump shaft 41 rotates. Thereby, the transmission member 50 transmits the rotation of the motor shaft 21 to the pump shaft 41. *

When the rotor 20 rotates and the motor shaft 21 rotates, the pump shaft 41 rotates through the transmission member 50, and the external gear 42 rotates. As a result, the internal gear 43 that meshes with the external gear 42 rotates, and the oil O sucked into the pump chamber 46 from the suction port 44 passes between the external gear 42 and the internal gear 43. It is sent to the discharge port 45. In this way, the pump unit 40 is driven via the motor shaft 21. A part of the oil O discharged from the discharge port 45 flows into the second oil passage 62 via the first oil passage 61. As indicated by an arrow in FIG. 3, the oil O that has flowed into the second oil passage 62 receives a force radially outward due to the centrifugal force of the rotating motor shaft 21, passes through the first through hole 26a, and the motor shaft 21. Out to the outside. *

In the present embodiment, since the first through hole 26a opens in the axial gap 27a between the first end plate 24 and the rotor core 22, the oil O flowing out of the first through hole 26a flows into the gap 27a. A part of the oil O flowing into the gap 27a is ejected radially outward from the ejection hole 24a. On the other hand, the other part of the oil O that has flowed into the gap 27a flows into the gap 27b through the rotor through hole 22a. The oil O that has flowed into the gap 27b is ejected radially outward from the ejection hole 25a. The oil O ejected radially outward from the ejection holes 24 a and 25 a is sprayed to the coil 32. Thereby, the coil 32 can be cooled by the oil O. Moreover, since the 2nd oil path 62 is provided in the inside of the motor shaft 21, the rotor 20 can also be cooled with the oil O until it ejects from the ejection holes 24a and 25a. In particular, since the magnet 23 can be cooled, demagnetization of the magnet 23 can be suppressed. *

FIG. 3 shows an example in which the oil O is ejected upward from the ejection holes 24a and 25a, but is not limited thereto. Since the rotor 20 rotates, the circumferential positions of the ejection holes 24 a and 25 a change as the rotor 20 rotates. Thereby, the direction of the oil O ejected from the ejection holes 24a and 25a changes in the circumferential direction, and the plurality of coils 32 arranged along the circumferential direction can be cooled by the oil O. *

Further, the other part of the oil O discharged from the discharge port 45 flows into the third oil passage 63 through the first oil passage 61 and the space 13b. The oil O that has flowed into the third oil passage 63 flows out of the

supply parts

63 c and 63 d and is supplied to the coil 32. Accordingly, the coil 32 can be further cooled by the oil O. In the present embodiment, since the third oil passage 63 opens into the accommodating portion 14 on the upper side of the stator 30, the oil O that has flowed out of the third oil passage 63 is supplied to the stator 30 from the upper side. Accordingly, the oil O can be supplied from the upper side to the lower side of the stator 30, and the entire stator 30 can be easily cooled by the oil O. *

As described above, the pump unit 40 can be driven by the rotation of the motor shaft 21, and the oil O stored in the housing 10 can be sucked up by the pump unit 40 and supplied to the rotor 20 and the stator 30. Thereby, the rotor 20 and the stator 30 can be cooled using the oil O stored in the housing 10. The oil O supplied to the stator 30 falls in the housing portion 14 and is stored again in the lower region of the housing portion 14. Thereby, the oil O in the accommodating part 14 can be circulated. *

According to the present embodiment, the suction port 44 for sucking the oil O into the pump chamber 46 opens in a lower region of the accommodating portion 14 where the oil O is stored. Therefore, the suction port 44 can be directly exposed to the oil O stored in the storage unit 14. This eliminates the need for an oil passage that guides the oil stored in the storage portion 14 into the pump chamber 46. Therefore, the oil path for sending the oil O by the pump unit 40 can be prevented from becoming complicated, and the structure of the drive device 1 including the pump unit 40 can be easily simplified. Thereby, according to this embodiment, the drive device 1 can be reduced in size. *

In addition, according to the present embodiment, since the suction port 44 is disposed below the rotor 20, the suction port 44 can be easily disposed below the liquid level OS of the oil O. Thereby, the oil O is easily sucked into the pump chamber 46 from the suction port 44. Further, even when the liquid level OS is arranged below the rotor 20, the suction port 44 can be arranged below the liquid level OS. Accordingly, it is possible to easily suck the oil O from the suction port 44 while suppressing the oil O from becoming the rotational resistance of the rotor 20 with the liquid level OS below the rotor 20. *

In the present embodiment, since at least a part of the suction port 44 is disposed below the liquid surface OS of the oil O, the suction port 44 can be more easily exposed to the oil O stored in the storage unit 14. Thereby, the oil O is more easily sucked into the pump chamber 46 from the suction port 44. *

In addition, according to the present embodiment, since the closing portion 12d that closes a part of the opening on the other axial side of the pump chamber 46 can be a part of the first portion 12, the second portion 13 is changed to the first portion 12. A part of the opening on the other side in the axial direction of the pump chamber 46 can be closed by attaching to the pump chamber 46. Thereby, it is not necessary to separately provide a member for closing the pump chamber 46, and the number of parts of the driving device 1 can be easily reduced. Further, by providing the opening portion 12 f in the first portion 12, the suction port 44 of the pump chamber 46 can be easily exposed to the housing portion 14. *

The present invention is not limited to the above-described embodiment, and other configurations can be employed. The blocking part 12d may be provided in the second portion 13. The pump chamber 46 may be provided in the first portion 12. In this case, the pump chamber 46 is recessed from the surface on the one side in the axial direction of the first portion 12 to the other side in the axial direction. Further, the first portion 12 and the second portion 13 may be a single member portion. *

The rotor core 22 may be fixed to the outer peripheral surface of the motor shaft 21 by press fitting or the like. In this case, the first end plate 24 and the second end plate 25 may not be provided. In this case, the oil O flowing out from the first through hole 26 a may be directly supplied to the coil 32, or a hole connected to the first through hole 26 a is provided in the rotor core 22 via the hole of the rotor core 22. Thus, the oil O may be supplied to the coil 32. Further, the oil O may be supplied to the stator core 31. Further, the third oil passage 63 may not be provided. *

The pump shaft 41 may be inclined with respect to the motor shaft 21. The plain bearing portion 12e may be above the liquid level OS. The pump shaft 41 may be rotatably supported by a ball bearing. The tooth profile of the tooth portion 42a of the external gear 42 and the tooth profile of the tooth portion 43a of the internal gear 43 may be a cycloid tooth profile or an involute tooth profile. *

In addition, the use of the drive apparatus of embodiment mentioned above is not specifically limited. Moreover, each structure mentioned above can be suitably combined in the range which is not mutually contradictory.

DESCRIPTION OF SYMBOLS 1 ... Drive device, 10 ... Housing, 12 ... 1st part, 12d ... Closure part, 12e ... Bearing part, 12f ... Opening part, 13 ... 2nd part, 14 ... Storage part, 20 ... Rotor, 21 ... Motor shaft, 26a ... 1st through-hole, 30 ... Stator, 40 ... Pump part, 41 ... Pump shaft, 42 ... External gear, 42a, 43a ... Tooth part, 43 ... Internal gear, 44 ... Suction port, 45 ... Discharge port, 46 ... pump chamber, 50 ... transmission member, 61 ... first oil passage, 62 ... second oil passage, 63 ... third oil passage, 70, 71 ... bearing, J1 ... central axis, O ... oil, OS ... liquid level , Z ... vertical direction

Claims

A rotor having a motor shaft disposed along a central axis extending in one direction;

A stator facing the rotor via a gap in the radial direction;

A housing having an accommodating portion capable of accommodating the rotor and the stator and storing oil;

A pump unit having a pump shaft disposed along an axis different from the central axis in the housing, and driven by the motor shaft;

A transmission member for transmitting rotation of the motor shaft to the pump shaft;

With

The pump part is

An external gear fixed to the pump shaft;

An internal gear surrounding the external gear and meshing with the external gear;

A pump chamber provided in the housing and accommodating the internal gear and the external gear;

A suction port capable of sucking oil into the pump chamber;

A discharge port capable of discharging oil from the pump chamber;

Have

The housing has a first oil passage connected to the discharge port,

The motor shaft is

A second oil passage provided inside the motor shaft and connected to the first oil passage;

A first through hole connecting the second oil passage and the outer peripheral surface of the motor shaft;

Have

The suction opening opens in a region on the lower side in the vertical direction of the housing portion, and is capable of sucking oil stored in the housing portion into the pump chamber.
The drive device according to claim 1, wherein the suction port is disposed vertically below the rotor.
3. The drive device according to claim 1, wherein at least a part of the suction port is disposed on a lower side in a vertical direction than a liquid level of oil stored in the housing portion.
4. The drive device according to claim 3, wherein when the rotor rotates, a liquid level of oil stored in the housing portion is arranged on a lower side in a vertical direction than the rotor.
The housing is

A first portion that holds a bearing that rotatably supports the motor shaft and covers one side of the stator in the axial direction;

A second portion attached to one axial side of the first portion and provided with the pump chamber;

Have

The pump chamber is recessed from the surface on the other axial side of the second portion to the one axial side,

The first part is

A closing part for closing a part of the opening on the other axial side of the pump chamber;

An opening that penetrates the first portion in the axial direction and exposes the suction port to the housing portion;

5. The drive device according to claim 1, comprising:
The closing portion has a sliding bearing portion that penetrates the closing portion in the axial direction,

The sliding bearing portion is located between the pump chamber and the housing portion in the axial direction,

The drive device according to claim 5, wherein the pump shaft is rotatably supported by the sliding bearing portion.
The drive device according to claim 6, wherein at least a part of the sliding bearing portion is disposed on a lower side in a vertical direction than a liquid level of oil stored in the housing portion.
The pump shaft extends in the axial direction of the motor shaft, and is disposed on a lower side in the vertical direction than the motor shaft on one axial side of the stator.

The drive device according to any one of claims 5 to 7, wherein the first oil passage is provided in the second portion.
The housing has a third oil passage connected to the first oil passage,

The drive device according to any one of claims 1 to 8, wherein the third oil passage opens into the housing portion on a vertical upper side of the stator.
The drive device according to any one of claims 1 to 9, wherein a tooth shape of the tooth portion of the external gear and a tooth shape of the tooth portion of the internal gear are trochoidal tooth shapes.