Unit

Abstract

The invention provides a cell for improving the layout of the cell. The unit has a bolt and a rotating electric machine. The rotating electrical machine includes a rotor and a stator surrounding an outer periphery of the rotor. The stator has a stator protrusion protruding radially outward on the outer periphery of the stator. The bolt is inserted into the stator protrusion in a direction from one axial end side of the stator toward the other axial end side. The neutral point of the stator and the head of the bolt are disposed on one axial end side of the stator. The neutral point of the stator is offset from the head of the bolt when viewed from the axial direction.

Description

Technical Field

[0001] The invention relates to a unit. Background Art

[0002] Patent Documents 1 and 2 disclose technologies for arranging the neutral point of a stator coil with a view to cooling performance.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: (Japanese) Patent Publication No. 2006-14438

[0006] Patent Document 2: (Japanese) Patent Publication No. 2010-252521 Summary of the invention

[0007] Problems to be solved by the invention

[0008] Since the coils are bundled at the neutral point, the volume of the stator increases by the amount of the coils protruding at the neutral point. Therefore, if the arrangement of the neutral point is not considered, the volume of the unit in which the stator is installed also increases, resulting in the possibility of deteriorating the layout of the unit.

[0009] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to improve the layout properties of cells.

[0010] Technical solutions to solve problems

[0011] A unit according to one embodiment of the present invention comprises a bolt and a rotating electric machine, wherein the rotating electric machine comprises a rotor and a stator surrounding the outer circumference of the rotor. The stator comprises a stator protrusion protruding radially outward from the outer circumference of the stator, and the bolt is inserted into the stator protrusion in a direction from one axial end side of the stator toward the other axial end side. The neutral point of the stator and the head of the bolt are arranged at one axial end side of the stator, and when viewed from the axial direction, the neutral point of the stator and the head of the bolt are offset.

[0012] Effects of the Invention

[0013] Here, a wall for fixing the bolts for retaining the stator in the housing is required on the other axial end side of the stator. As a result, the axial space of the unit becomes smaller on the other axial end side. On the other hand, since the axial one end side of the stator is the side where the bolts are inserted, there is no such restriction, and the axial space of the unit is more generous than on the other axial end side.

[0014] Therefore, in the above-mentioned method, the neutral point is arranged on one axial end side of the stator. As a result, the axial space of the unit on the one axial end side of the stator can be effectively utilized, so that the volume of the unit can be suppressed from increasing due to the extension of the coil at the neutral point. As a result, compared with the case where the neutral point is arranged on the other axial end side of the stator, the layout of the unit in at least the axial direction can be improved.

[0015] Furthermore, even if the neutral point is arranged at a position overlapping with the head of the bolt when viewed from the axial direction on one axial end side of the stator, the coil will protrude excessively in the axial direction at the neutral point because a space corresponding to the thickness of the bolt head or an insulation distance from the bolt head is required in the axial direction. As a result, the volume of the unit increases, and the layout of the unit may be reduced.

[0016] According to the above aspect, since the neutral point is arranged at a position offset from the head of the bolt when viewed from the axial direction, the coil will not be excessively extended in the axial direction due to the head of the bolt. Therefore, from this aspect, the layout of the unit in at least the axial direction can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of the unit of this embodiment.

[0018] Figure 2 This is a diagram showing the unit as viewed from one axial side with the cover removed.

[0019] Figure 3 This is a diagram showing the unit from the other axial side with the cover removed. DETAILED DESCRIPTION

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0021] Figure 1 It is a schematic structural diagram of the unit 100 according to this embodiment. Figure 2 This is a diagram showing the unit 100 as viewed from one axial side in a state where the first cover 11 is removed. Figure 3 The unit 100 is viewed from the other axial side with the second cover 12 removed. Figure 1 In FIG. 1 , the power transmission structure of the unit 100 is shown in a planar form. Figure 1 In the figure, the direction perpendicular to the paper plane corresponds to the direction of gravity. Figure 2 , Figure 3 , the up and down directions correspond to the direction of gravity.

[0022] Regarding the terminology of the unit, the unit may also be referred to as, for example, a motor unit (a unit having at least a motor) or a power transmission device (a device having at least a power transmission mechanism). The motor is a rotating electrical machine having a motor function and / or a generator function (at least one of the motor function and the generator function). The power transmission mechanism is, for example, a gear mechanism and / or a differential gear mechanism. A device (unit) having a motor and a power transmission mechanism is included in the concepts of a motor unit and a power transmission device.

[0023] Unit 100 Figure 1 As shown in FIG. 1 , a housing 10, a rotating electrical machine 20, a speed reduction mechanism 30, a differential gear 40, and bolts 50 are provided. Figure 2 The connector terminal 60 is shown.

[0024] The unit 100 is mounted on a vehicle. The vehicle is an electric vehicle. The housing 10 has a first cover 11, a second cover 12, and a housing 13. The rotating electric machine 20, the speed reduction mechanism 30, and the differential gear 40 are accommodated in the housing 10. The first cover 11 is axially extending from one side ( Figure 1 The left side of the cylindrical housing 13 is blocked by the second cover 12, and the second cover 12 is axially extended from the other side ( Figure 2 The right side of the housing 13 blocks the opening of the housing 13. The rotating electrical machine 20 is accommodated in the housing 13, and the differential gear 40 is accommodated in the second cover 12.

[0025] The rotating electric machine 20 includes a rotor 21, a stator 22, and a rotating shaft 23, and constitutes a driving source of the vehicle. The rotor 21 is disposed on the outer periphery of the rotating shaft 23. The stator 22 is disposed on the housing 13. The stator 22 accommodates the rotor 21 and surrounds the outer periphery of the rotor 21. Figure 1 As shown, the rotating shaft 23 protrudes from the rotor 21 toward both sides in the axial direction. The rotating shaft 23 penetrates the first cover 11 on one side in the axial direction and penetrates the housing 13 on the other side in the axial direction. A bearing 51 is provided on the first cover 11 at the portion through which the rotating shaft 23 penetrates, and a bearing 52 is provided on the housing 13 at the portion through which the rotating shaft 23 penetrates, and the rotating shaft 23 is supported by the bearing 51 and the bearing 52. A resolver 80 is provided on the portion of the rotating shaft 23 protruding from the first cover 11. The resolver 80 detects the rotation of the rotating electric machine 20. The stator 22 will be further described later.

[0026] The speed reduction mechanism 30 is a gear mechanism, and includes a first gear 31, a second gear 32, a third gear 33, a fourth gear 34, a fifth gear 35, a sixth gear 36, a shaft 37, and a shaft 38. The speed reduction mechanism 30 is a four-axis speed reduction mechanism, and includes a first shaft AX1, a second shaft AX2, a third shaft AX3, and a fourth shaft AX4. The first shaft AX1, the second shaft AX2, the third shaft AX3, and the fourth shaft AX4 all constitute the shaft of the unit 100 and extend in the same direction.

[0027] Therefore, the extension directions of the first axis AX1, the second axis AX2, the third axis AX3, and the fourth axis AX4 are all equivalent to the axial direction of the unit 100. That is, the axial direction refers to the axial direction of the rotating axis of the parts (such as the motor, the gear mechanism, and the differential gear mechanism) constituting the unit. The radial direction of the unit 100 is a direction orthogonal to any one of the first axis AX1, the second axis AX2, the third axis AX3, and the fourth axis AX4. The first axis AX1 constitutes the axis of the rotating axis 23, the second axis AX2 constitutes the axis of the axis 37, the third axis AX3 constitutes the axis of the axis 38, and the fourth axis AX4 constitutes the axis of the differential gear 40.

[0028] The first gear 31 is arranged on the first axis AX1 together with the rotating motor 20. In other words, the rotating motor 20 and the first gear 31 are arranged coaxially with respect to the first axis AX1. Similarly, the second gear 32 and the third gear 33 are arranged on the second axis AX2, and the fourth gear 34 and the fifth gear 35 are arranged on the third axis AX3. The sixth gear 36 and the differential gear 40 are arranged on the fourth axis AX4.

[0029] like Figure 3 As shown, the first axis AX1 and the fourth axis AX4 are arranged below the second axis AX2 and the third axis AX3 when viewed from the axial direction.

[0030] The upper side and the lower side refer to the upper and lower relationship in the gravity direction when observing in a specified direction including axial observation and radial observation. For example, when observing from the axial direction, the first element is located obliquely above the second element in a state where the first element does not overlap with the second element in the gravity direction, and when observing from the radial direction, the first element is located above the second element when the first element and the second element do not overlap.

[0031] Overlapping when viewed from a specified direction including radial and axial observations means overlapping in the specified direction, which means that a plurality of elements are arranged in the specified direction. Therefore, when a plurality of elements are illustrated in the drawings as being arranged in a specified direction, it can be considered that there is a description in the specification that a plurality of elements overlap when viewed from the specified direction.

[0032] As a result of the above arrangement, the first axis AX1 and the fourth axis AX4 are concentrated on the lower side of the unit 100 in the direction of gravity.

[0033] like Figure 1As shown, the first gear 31 is provided on the rotating shaft 23 of the portion protruding from the housing 13 on the other side of the axial direction than the rotor 21. The second gear 32 is provided on the shaft 37 and meshes with the first gear 31. The number of teeth of the second gear 32 is set to be greater than that of the first gear 31, and together with the first gear 31, it constitutes a first reduction gear stage. The third gear 33 is provided on the shaft 37 on the side farther from the rotating electric machine 20 than the second gear 32, that is, on the other side of the axial direction. The shaft 37 is supported at both ends by a bearing 53 provided on the housing 13 and a bearing 54 provided on the second cover 12.

[0034] The fourth gear 34 is provided on the shaft 38 and meshes with the third gear 33. The number of teeth of the fourth gear 34 is set to be greater than that of the third gear 33, and together with the third gear 33, it constitutes a second reduction gear stage. The fifth gear 35 is provided on the shaft 38. The fifth gear 35 is provided on the shaft 38 on the side closer to the rotating electric machine 20 than the fourth gear 34, that is, on the axial side. The shaft 38 is supported at both ends by a bearing 55 provided on the housing 13 and a bearing 56 provided on the second cover 12.

[0035] The sixth gear 36 meshes with the fifth gear 35. The sixth gear 36 is a final transmission gear, and is provided on the differential gear 40. The power from the rotary electric machine 20 is transmitted from the sixth gear 36 to the differential gear 40. The sixth gear 36 overlaps with the first gear 31 when viewed from the radial direction. The sixth gear 36 overlaps with the first gear 31 when viewed from the radial direction along a plane including the first axis AX1 and the fourth axis AX4, for example.

[0036] The sixth gear 36 has a larger number of teeth than the fifth gear 35 and forms a third reduction gear stage together with the fifth gear 35. Therefore, in the reduction mechanism 30, three reduction stages are performed by the first gear 31 and the second gear 32, the third gear 33 and the fourth gear 34, and the fifth gear 35 and the sixth gear 36.

[0037] The differential gear 40 is a differential gear mechanism, and includes a differential case 41 and a differential portion 42. The sixth gear 36 may also grasp a part of the differential gear 40. The differential case 41 is supported by a bearing 57 provided on the housing 13 and a bearing 58 provided on the second cover 12, and rotates together with the sixth gear 36. The sixth gear 36 is coaxially fixed to the outer wall portion of the differential case 41, and the differential case 41 accommodates the differential portion 42. The differential portion 42 distributes the power input to the differential case 41 via the sixth gear 36 to the drive wheels in the left and right directions of the vehicle and outputs the power.

[0038] The differential gear 40 is arranged in a direction close to and away from the stator 22 with respect to the sixth gear 36. Thus, the differential gear 40 is arranged in a space on the end side of the unit 100 formed by the gear arrangement of the speed reduction mechanism 30.

[0039] The first drive shaft 61 is assembled from one axial side to the differential portion 42, and the second drive shaft 62 is assembled from the other axial side. The power from the rotary electric machine 20 is transmitted from the differential portion 42 to one drive wheel via the first drive shaft 61, and to the other drive wheel via the second drive shaft 62. The first drive shaft 61 is longer than the second drive shaft 62, and is supported by a bearing 59 provided on the first cover 11.

[0040] Next, the stator 22 will be further described.

[0041] like Figure 1 As shown, the stator 22 includes a stator core 221 and a coil 222. The stator core 221 is formed by laminating a plurality of electromagnetic steel sheets. A protrusion 221a is provided on the stator core 221, and a through hole 221a is provided on the protrusion 221a that penetrates the stator core 221 in the axial direction.

[0042] like Figure 2 As shown, the protrusion 221a protrudes radially outward from the outer circumference of the stator 22. The protrusion 221a is provided to protrude radially outward from the outer circumference of the circular portion of the stator core 221, and protrudes radially outward compared to the outer circumferences of the circular portions adjacent to each other on both sides of the circumferential direction. A plurality of protrusions 221a (here, three) are provided in the circumferential direction. The plurality of protrusions 221a can be provided evenly in the circumferential direction.

[0043] The bolt 50 is inserted into the protrusion 221a. The bolt 50 is a through bolt and becomes a conductive object. The bolt 50 is provided in plurality by being provided on a plurality of protrusions 221a. Figure 1 As shown, a through hole 221a is provided on the protrusion 221a. The bolt 50 is inserted into the through hole 221aa in the direction from one axial end side toward the other axial end side of the stator 22, thereby inserting the protrusion 221a in the direction. One axial end side of the stator 22 corresponds to one axial side of the unit 100, and the other axial end side of the stator 22 corresponds to the other axial side of the unit 100.

[0044] The wall portion 13a of the housing 13 is present on the other axial end side of the stator 22. The portion of the wall portion 13a opposite to the protrusion 221a is formed into a boss shape, and a bolt hole 13aa is provided in this portion. The bolt 50 is fastened to the bolt hole 13aa in a state of being inserted into the protrusion 221a, thereby being fixed to the wall portion 13a. Thus, the stator 22 is bolted to the housing 13 by the wall portion 13a. A plurality of bolt holes 13aa are provided corresponding to the protrusion 221a or the through hole 221aa. The protrusion 221a is equivalent to the stator protrusion.

[0045] like Figure 1 , Figure 2As shown, the coil 222 has a coil end 222a and a neutral point 222b. The coil end 222a is formed on both sides of the axial direction of the stator 22. The neutral point 222b is a portion where the coils of each phase, namely, the U phase, the V phase, and the W phase, which constitute the coil 222, are bundled. The coil 222 forms the neutral point 222b at one end and is connected to the connector terminal 60 at the other end.

[0046] The connector terminal 60 includes a terminal 60u, a terminal 60v, and a terminal 60w, and is electrically connected to the stator 22. The U-phase coil is connected to the terminal 60u, the V-phase coil is connected to the terminal 60v, and the W-phase coil is connected to the terminal 60w.

[0047] from Figure 1 , Figure 2 It can be seen that the neutral point 222b and the head 50a of the bolt 50 are arranged on the axial one end side of the stator 22. Since the axial one end side of the stator 22 is the side where the bolt 50 is inserted, there is no need for a wall portion such as the wall portion 13a for fixing the bolt 50. Therefore, the axial space restriction of the unit 100 caused by the wall portion 13a on the axial other end side does not exist on the axial one end side.

[0048] Therefore, in the unit 100, the neutral point 222b is arranged on the axial one end side of the stator 22. Thus, the axial space of the unit 100 is effectively utilized on the axial one end side of the stator 22. Therefore, compared with the case where the neutral point 222b is arranged on the axial other end side of the stator 22, the volume of the unit 100 can be suppressed from increasing due to the extension of the coil 222 at the neutral point 222b. As a result, the layout of the unit 100 is improved at least in the axial direction.

[0049] like Figure 2 As shown, the neutral point 222b is offset from the head 50a when viewed from the axial direction. In other words, the neutral point 222b does not overlap with the head 50a when viewed from the axial direction, and does not have overlap with the head 50a. Therefore, there is no unnecessary axial extension of the coil 222 that requires a space of the thickness of the head 50a or an insulation distance from the head 50a in the axial direction. As a result, from such a perspective, the layout of the unit 100 is improved at least in the axial direction. The neutral point 222b can be configured to protrude radially outward from the rotating electrical machine 20 when viewed from the axial direction, and in the present embodiment, it is a slightly protruding configuration.

[0050] The neutral point 222b is arranged to avoid the region R between the protrusion 221a and the rotor 21 when viewed from the axial direction. Figure 2, but each protrusion 221a has a region R. The region R is a region divided between the root of the protrusion 221a in the stator core 221 (the radially inner boundary portion of the protrusion 221a defined by the outer diameter of the circular portion of the stator 22) and the outer periphery of the rotor 21 when viewed from the axial direction.

[0051] The region R is the region between the root of the protrusion 221a and the center of the rotor 21 when viewed from the axial direction. Figure 2 Such region R can be, for example, a region divided between two lines parallel to a line including the centers of the rotor 21 and the through hole 221aa and including both circumferential ends of the protrusion 221a when viewed from the axial direction.

[0052] The reason why the neutral point 222 b is arranged avoiding the region R when viewed from the axial direction is as follows.

[0053] Here, in order to offset the neutral point 222b from the head 50a when viewed from the axial direction, the neutral point 222b may be arranged near the root of the protrusion 221a while avoiding the head 50a. However, in this case, in order to ensure the insulation distance between the bolt 50 and the neutral point 222b, the bolt 50 is arranged to be away from the neutral point 222b toward the radial outside. As a result, the stator 22 must be expanded in the radial direction.

[0054] Therefore, in the unit 100, such a situation is avoided by arranging the neutral point 222b away from the region R when viewed from the axial direction. As a result, the layout property of the unit 100 is improved at least in the radial direction.

[0055] The housing 10 has a peripheral wall portion 13b surrounding the rotating electrical machine 20 and the first drive shaft 61 when viewed from the axial direction. The peripheral wall portion 13b is a peripheral wall portion of the case 13 of the housing 10, and the first drive shaft 61 constitutes a shaft connected to the downstream power of the rotating electrical machine 20.

[0056] Here, in the structure in which the rotating electrical machine 20 and the first drive shaft 61 are arranged in the same chamber surrounded by a peripheral wall portion 13b when viewed from the axial direction, there is the following spatial margin in the structure. That is, in such a structure, Figure 1 , Figure 2 As shown, there is a spatial margin on one axial end side of the stator 22 at the rotation center of the rotary electric machine 20 , that is, on the side where the first drive shaft 61 is arranged when viewed from the first axis AX1 .

[0057] Therefore, the neutral point 222b is located between the first vertical line V1 passing through the rotation center of the rotor 21 and the second vertical line V2 passing through the fourth axis AX4 which is the rotation center of the first drive shaft 61 when viewed from the axial direction. Thus, as described above, since the neutral point 222b is arranged in a form that effectively utilizes the space with a surplus in the space, the volume of the unit 100 can be suppressed from increasing due to the neutral point 222b, and the layout of the unit 100 is improved.

[0058] like Figure 2 As shown, the connector terminal 60 is arranged on one axial end side of the stator 22. As a result, the neutral point 222b, the head 50a, and the connector terminal 60 that can affect the volume of the unit 100 at least in the axial direction are all gathered on one axial end side of the stator 22. As a result, compared with the case where the connector terminal 60 is arranged on the other axial end side of the stator 22, the layout of the unit 100 is improved at least in the axial direction.

[0059] like Figure 2 , Figure 3 As shown, the unit 100 has oil OL. The oil OL is supplied to the rotating electric machine 20 in the housing 13 from the outside of the housing 10, for example, to lubricate the rotating electric machine 20. A part of the oil OL supplied to the rotating electric machine 20 is stored in the housing 10 and is contained in the housing 10. The remaining oil OL is discharged to the outside of the housing 10. The oil OL can be circulated inside and outside the housing 10.

[0060] The housing 13 has a through hole 13c. The through hole 13c is formed in the portion of the housing 13 that is lower than the first axis AX1 and the fourth axis AX4 in the direction of gravity, and connects the inside of the second cover 12 and the inside of the housing 13. Therefore, as shown by the arrow, the oil OL in the housing 13 can flow into the second cover 12 through the through hole 13c, and is also used for lubrication of the differential gear 40. Oil reservoirs are respectively formed in the second cover 12 and the housing 13 at the lower part in the direction of gravity. The oil reservoir of the unit 100 is also formed in the first cover 11.

[0061] like Figure 2 As shown, the neutral point 222b is arranged at least at a position where it is immersed in oil during the running of the vehicle. The neutral point 222b is immersed in oil (immersed in oil OL) in the oil reservoir, and is arranged below the oil level LV in the direction of gravity. The oil level LV is the oil level of the oil reservoir of the housing 10 in a stable circulation state, and becomes the common oil level height of the oil reservoir in the first cover 11, the second cover 12, and the housing 13.

[0062] The stable circulation state is a state in which the circulation of the oil OL becomes stable. For example, when the oil is circulated using a pump, the oil level LV becomes stable during the operation of the pump. The oil circulation may also be performed by stirring the oil OL by rotating parts such as gears in the housing 10. In this case, the stable circulation state is a state in which the oil level LV becomes stable during the rotation of the rotating parts.

[0063] The oil level LV is set to a height at which the stator 22 is immersed in the oil OL in a stable circulation state and the oil OL does not enter the air gap AG which is a gap between the rotor 21 and the stator 22 of the rotary electric machine 20. This is because when the oil OL enters the air gap AG, the rotation resistance of the rotary electric machine 20 increases sharply, while the stator 22 wants to be cooled.

[0064] Therefore, by setting the oil level LV as described above, the oil OL is set to contact the coil end 222a of the stator 22. The oil level LV is set to a position overlapping the through hole 13c when viewed from the axial direction in a stable circulation state.

[0065] The stable circulation state is established at least when the vehicle is running, and the neutral point 222b is immersed in the oil, for example, in the stable circulation state when the vehicle is running. When the vehicle is running, in other words, when the rotating electric machine 20 is driven, in the neutral point 222b where the coils of each phase are bundled, the coil 222 is particularly likely to generate heat during the driving of the rotating electric machine 20. Therefore, it is preferable to set the configuration in which the neutral point 222b is immersed in the oil while the vehicle is running, so that the temperature rise of the neutral point 222b can be appropriately suppressed.

[0066] The neutral point 222b has nothing to do with whether it is in a stable circulation state. For example, when the oil level in the oil storage section drops while the vehicle is running, it can be configured at a position lower than the dropped oil level. In addition, when the oil level is inclined while the vehicle is running, it can be configured at a position lower than the inclined oil level.

[0067] That is, the neutral point 222b can be arranged at a position immersed in the oil while the vehicle is running, regardless of the up and down position of the oil level or the inclination of the oil level that changes during the vehicle's running. Alternatively, the neutral point 222b is preferably arranged at a position immersed in the oil while the vehicle is running, regardless of the change of the oil level during the vehicle's running, including the up and down position of the oil level or the inclination of the oil level. The change of the oil level during the vehicle's running can be any change as long as it is within the assumed range of the design.

[0068] Next, the main effects of this embodiment will be described.

[0069] (1) The unit 100 includes a bolt 50 and a rotating electrical machine 20. The rotating electrical machine 20 includes a rotor 21 and a stator 22 surrounding the outer circumference of the rotor 21. The stator 22 includes a protrusion 221a protruding radially outward from the outer circumference of the stator 22. The bolt 50 is inserted into the protrusion 221a in a direction from one axial end side toward the other axial end side of the stator 22. The neutral point 222b of the stator 22 and the head 50a of the bolt 50 are arranged on one axial end side of the stator 22. When viewed from the axial direction, the neutral point 222b of the stator 22 and the head 50a of the bolt 50 are offset.

[0070] According to such a structure, the axial space of the unit 100 on one axial end side of the stator 22 can be effectively utilized. Therefore, it is possible to suppress the situation where the volume of the unit 100 increases due to the extension of the coil 222 at the neutral point 222b. As a result, compared with the case where the neutral point 222b is configured on the other axial end side of the stator 22, the layout of the unit 100 in at least the axial direction can be improved. In addition, because the neutral point 222b is configured at a position offset from the head 50a when viewed from the axial direction, there will be no unnecessary extension of the coil 222 in the axial direction due to the head 50a. Therefore, from this aspect, it is also possible to improve the layout of the unit 100 in at least the axial direction.

[0071] (2) In the unit 100, when viewed from the axial direction, the neutral point 222b of the stator 22 is arranged to avoid the region R between the protrusion 221a and the rotor 21. According to such a structure, it is possible to avoid a situation where the position of the bolt 50 is separated from the neutral point 222b toward the radial outer side in order to ensure the insulation distance between the bolt 50 and the neutral point 222b. Therefore, the layout of the unit 100 can be improved at least in the radial direction.

[0072] (3) The unit 100 has a housing 10 that accommodates the rotating electric machine 20 and a first drive shaft 61 that is connected to the downstream power of the rotating electric machine 20. The housing 10 has a peripheral wall portion 13b that surrounds the rotating electric machine 20 and the first drive shaft 61 when viewed from the axial direction. When viewed from the axial direction, the neutral point 222b is located between a first vertical line V1 passing through the rotation center of the rotor 21 and a second vertical line V2 passing through the rotation center of the first drive shaft 61.

[0073] According to such a configuration, in a configuration in which the rotating electrical machine 20 and the first drive shaft 61 are arranged in the same chamber surrounded by one peripheral wall portion 13b when viewed from the axial direction, the neutral point 222b can be arranged in a form that effectively utilizes the spare space on the axial end side of the stator 22. Therefore, the layout of the unit 100 can be improved.

[0074] (4) The unit 100 is used in a vehicle and has oil OL. The neutral point 222b is at least arranged at a position immersed in the oil during the vehicle running. According to such a structure, the temperature rise at the neutral point 222b which is particularly prone to heat generation during the driving of the rotating electric machine 20 can be appropriately suppressed by cooling the oil OL.

[0075] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate a part of application examples of the present invention and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0076] Description of Reference Numerals

[0077] 10 Shell

[0078] 13 Shell

[0079] 13b peripheral wall

[0080] 20 Rotary motor

[0081] 21 rotor

[0082] 22 stator

[0083] 221 stator core

[0084] 221a protrusion (stator protrusion)

[0085] 222 Coil

[0086] 222a Coil end

[0087] 222b Neutral point

[0088] 30 speed reduction mechanism

[0089] 40 Differential gear

[0090] 50 bolts

[0091] 50a Head

[0092] 60 connector terminals

[0093] 61 first drive shaft (shaft)

[0094] 100 units

[0095] LV oil level

[0096] OL Oil

[0097] R Region

[0098] V1 first vertical line

[0099] V2 second vertical line

Claims

1. A unit, characterized in that With bolts and a rotating motor, The rotating electrical machine includes a rotor and a stator surrounding the outer circumference of the rotor. The stator has a stator protrusion protruding radially outward on the outer periphery of the stator. The bolt is inserted into the stator protrusion in a direction from one axial end side toward the other axial end side of the stator. The neutral point of the stator and the head of the bolt are arranged on one axial end side of the stator. When viewed from the axial direction, the neutral point of the stator is offset from the head of the bolt.

2. The unit according to claim 1, characterized in that When viewed in the axial direction, the neutral point of the stator is arranged to avoid a region between the stator protrusion and the rotor.

3. The unit according to claim 1, characterized in that have: a housing that accommodates the rotating electrical machine; a shaft, which is connected to the downstream power of the rotating electric machine, The housing has a peripheral wall portion surrounding the rotating electrical machine and the shaft when viewed from the axial direction. When viewed from the axial direction, the neutral point is located between a first vertical line passing through a rotation center of the rotor and a second vertical line passing through a rotation center of the shaft.

4. The unit according to any one of claims 1 to 3, characterized in that The unit is used in a vehicle, The neutral point is arranged at least at a position where the vehicle is immersed in oil during running.

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