unit

Abstract

[Problem] To improve layout performance of a unit. [Solution] This unit comprises: a bolt; and a rotary electrical machine. The rotary electrical machine has a rotor and a stator that surrounds the outer circumference of the rotor. The stator has a stator projection part that projects outward in a radial direction on the outer circumference of the stator. The bolt is inserted into the stator projection part in a direction from one end side toward the other end side in the axial direction of the stator. A neutral point of the stator and a head of the bolt are disposed on the one end side in the axial direction of the stator. In an axial-direction view, the neutral point of the stator is offset from the head of the bolt.

Description

[Technical Field]

[0001] The present invention relates to a unit. [Background technology]

[0002] Patent Documents 1 and 2 disclose techniques for arranging the neutral point of the stator coil with an eye on cooling performance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-14438 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-252521 Summary of the Invention [Problem to be solved by the invention]

[0004] Since the coils are bundled at the neutral point, the size of the stator increases by the amount of the coils that protrude from the neutral point. Therefore, if the location of the neutral point is not taken into consideration, the size of the unit in which the stator is installed will also increase, which may result in a decrease in the layout flexibility of the unit.

[0005] The present invention has been made in view of the above problems, and has as its object to improve the layout flexibility of units. [Means for solving the problem]

[0006] According to one aspect of the present invention, a unit includes a bolt and a rotating electric machine, the rotating electric machine including a rotor and a stator surrounding the outer periphery of the rotor. The stator has a stator protrusion protruding radially outward from the outer periphery of the stator, and the bolt is inserted into the stator protrusion in a direction from one axial end of the stator to the other axial end. The neutral point of the stator and the head of the bolt are located at the one axial end of the stator, and the neutral point of the stator is offset from the head of the bolt in an axial view. [Effects of the Invention]

[0007] Here, a wall is required on the other axial end of the stator to secure the bolts that secure the stator to the housing. As a result, the axial space of the unit is smaller on the other axial end. In contrast, one axial end of the stator is the side where the bolts are inserted, so there is no such restriction, and the axial space of the unit is more generous compared to the other axial end.

[0008] Therefore, in the above-described embodiment, the neutral point is located at one axial end of the stator. This allows for effective use of the axial space of the unit at one axial end of the stator, thereby preventing the unit from becoming larger in size due to the coil protruding at the neutral point. As a result, the layout flexibility of the unit can be improved at least in the axial direction compared to when the neutral point is located at the other axial end of the stator.

[0009] Furthermore, even if the neutral point is located at one axial end of the stator, if it is positioned so as to overlap with the head of a bolt as viewed in the axial direction, a space equivalent to the thickness of the bolt head and an insulating distance from the bolt head are required in the axial direction, which causes the coil to protrude more in the axial direction at the neutral point. As a result, the size of the unit increases, which can reduce the layout flexibility of the unit.

[0010] According to the above aspect, since the neutral point is located at a position offset from the head of the bolt in the axial direction, the coil does not protrude excessively in the axial direction due to the head of the bolt, which also improves the layout flexibility of the unit at least in the axial direction. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of the unit according to this embodiment. [Figure 2] FIG. 2 is a view of the unit viewed from one axial side with the cover removed. [Figure 3] FIG. 3 is a view of the unit viewed from the other axial side with the cover removed. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0013] Fig. 1 is a schematic diagram of a unit 100 according to this embodiment. Fig. 2 is a view of the unit 100 viewed from one axial side with the first cover 11 removed. Fig. 3 is a view of the unit 100 viewed from the other axial side with the second cover 12 removed. Fig. 1 shows the power transmission structure of the unit 100 developed in a planar form. In Fig. 1, the direction perpendicular to the paper surface corresponds to the direction of gravity, and in Figs. 2 and 3, the up-and-down direction corresponds to the direction of gravity.

[0014] Regarding the term "unit," a unit can also be called, 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). A motor is a rotating electric machine having an electric motor function and / or a generator function (at least one of an electric motor function and a generator function). A 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 both a motor unit and a power transmission device.

[0015] The unit 100 includes a housing 10, a rotating electrical machine 20, a speed reduction mechanism 30, a differential gear 40, and a bolt 50 as shown in FIG. 1, and also includes a connector terminal 60 as shown in FIG.

[0016] 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 case 13. The rotating electric machine 20, the reduction mechanism 30, and the differential gear 40 are housed in the housing 10. The first cover 11 closes the opening of the cylindrical case 13 from one axial side (the left side in FIG. 1), and the second cover 12 closes the opening of the case 13 from the other axial side (the right side in FIG. 2). The rotating electric machine 20 is housed in the case 13, and the differential gear 40 is housed in the second cover 12.

[0017] The rotating electric machine 20 includes a rotor 21, a stator 22, and a rotating shaft 23, and constitutes a drive source for the vehicle. The rotor 21 is provided on the outer periphery of the rotating shaft 23. The stator 22 is provided in the case 13. The stator 22 houses the rotor 21 and surrounds the outer periphery of the rotor 21. As shown in FIG. 1 , the rotating shaft 23 protrudes from the rotor 21 on both axial sides. The rotating shaft 23 penetrates the first cover 11 on one axial side and the case 13 on the other axial side. 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 case 13 at the portion through which the rotating shaft 23 penetrates, and the rotating shaft 23 is supported by the bearings 51 and 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 described in more detail below.

[0018] The 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 reduction mechanism 30 is a four-axis reduction mechanism and has a first axis AX1, a second axis AX2, a third axis AX3, and a fourth axis AX4. The first axis AX1, the second axis AX2, the third axis AX3, and the fourth axis AX4 all constitute the axes of the unit 100 and extend along the same direction.

[0019] Therefore, the extension directions of the first axis AX1, the second axis AX2, the third axis AX3, and the fourth axis AX4 all correspond to the axial direction of the unit 100. In other words, the axial direction refers to the axial direction of the rotating shaft of the component that constitutes the unit (for example, a motor, a gear mechanism, or a differential gear mechanism). The radial direction of the unit 100 is a direction perpendicular to any 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 shaft 23, the second axis AX2 the axis of the shaft 37, the third axis AX3 the axis of the shaft 38, and the fourth axis AX4 the axis of the differential gear 40.

[0020] The first gear 31 is disposed on the first axis AX1 together with the rotating electric machine 20. In other words, the rotating electric machine 20 and the first gear 31 are disposed coaxially with respect to the first axis AX1. Similarly, the second gear 32 and the third gear 33 are disposed on the second axis AX2, and the fourth gear 34 and the fifth gear 35 are disposed on the third axis AX3. The sixth gear 36 and the differential gear 40 are disposed on the fourth axis AX4.

[0021] As shown in FIG. 3, the first axis AX1 and the fourth axis AX4 are disposed below the second axis AX2 and the third axis AX3 when viewed in the axial direction.

[0022] The terms "upper side" and "lower side" refer to the vertical relationship in the direction of gravity when viewed in a specific direction, including an axial direction or a radial direction. For example, when viewed in the axial direction, if a first element is positioned diagonally above a second element without overlapping with the second element in the direction of gravity, and when viewed in the radial direction, the first element is above the second element.

[0023] "Overlapping" when viewed in a predetermined direction, including radial and axial directions, means overlapping in the predetermined direction, meaning that multiple elements are lined up in the predetermined direction. Therefore, when a drawing shows multiple elements lined up in a predetermined direction, it can be considered that the specification contains a sentence explaining that multiple elements overlap when viewed in the predetermined direction.

[0024] As a result of the above-described 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.

[0025] 1, the first gear 31 is provided on the rotary shaft 23 at a portion that protrudes from the case 13 on the other axial side of the rotor 21. The second gear 32 is provided on the shaft 37 and meshes with the first gear 31. The second gear 32 has a larger number of teeth than the first gear 31 and, together with the first gear 31, forms a first reduction gear stage. The third gear 33 is provided on the shaft 37 on the side that is farther from the rotary electric machine 20 than the second gear 32, i.e., on the other axial side. The shaft 37 is supported at both ends by bearings 53 provided in the case 13 and bearings 54 provided in the second cover 12.

[0026] The fourth gear 34 is provided on the shaft 38 and meshes with the third gear 33. The fourth gear 34 is set to have a larger number of teeth than the third gear 33 and, together with the third gear 33, forms 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 a side closer to the rotating electric machine 20 than the fourth gear 34, i.e., on one axial side. The shaft 38 is supported at both ends by bearings 55 provided in the case 13 and bearings 56 provided in the second cover 12.

[0027] The sixth gear 36 meshes with the fifth gear 35. The sixth gear 36 is a final gear and is provided in the differential gear 40. Power from the rotating 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 in the radial direction. The sixth gear 36 overlaps with the first gear 31 when viewed in the radial direction along a plane including the first axis AX1 and the fourth axis AX4, for example.

[0028] The sixth gear 36 has a larger number of teeth than the fifth gear 35, and constitutes a third reduction gear stage together with the fifth gear 35. Therefore, in the reduction mechanism 30, three stages of reduction are achieved 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.

[0029] The differential gear 40 is a differential gear mechanism and includes a differential case 41 and a differential portion 42. The sixth gear 36 can also be considered to be part of the differential gear 40. The differential case 41 is supported by a bearing 57 provided in the case 13 and a bearing 58 provided in 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 houses the differential portion 42. The differential portion 42 distributes and outputs the power input to the differential case 41 via the sixth gear 36 to each of the drive wheels on the left and right sides of the vehicle.

[0030] The differential gear 40 is disposed in a direction away from the stator 22 relative to the sixth gear 36. As a result, the differential gear 40 is disposed in a space on the end side of the unit 100 formed in accordance with the gear arrangement of the reduction mechanism 30.

[0031] A first drive shaft 61 is attached to one axial side of the differential part 42, and a second drive shaft 62 is attached to the other axial side. Power from the rotating electric machine 20 is transmitted from the differential part 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 in the first cover 11.

[0032] Next, the stator 22 will be further described.

[0033] 1, stator 22 has stator core 221 and coil 222. Stator core 221 is formed by laminating a plurality of electromagnetic steel plates. Stator core 221 is provided with protrusions 221a, and protrusions 221a are provided with through holes 221aa that pass through stator core 221 in the axial direction.

[0034] As shown in Fig. 2, the protrusions 221a protrude radially outward from the outer periphery of the stator 22. The protrusions 221a are provided so as to protrude radially outward beyond the outer periphery of the circular portion of the stator core 221, and therefore protrude radially outward beyond the outer peripheries of the circular portions adjacent to each other on both sides in the circumferential direction. A plurality of protrusions 221a (three in this example) are provided in the circumferential direction. The plurality of protrusions 221a can be provided evenly in the circumferential direction.

[0035] A bolt 50 is inserted into the protrusion 221a. The bolt 50 is a through bolt and is electrically conductive. A plurality of bolts 50 are provided, one for each of the plurality of protrusions 221a. As shown in FIG. 1 , a through hole 221aa is provided in the protrusion 221a. The bolt 50 is inserted into the through hole 221aa in a direction from one axial end side of the stator 22 toward the other axial end side, and is thereby inserted into the protrusion 221a in the same direction. The 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.

[0036] A wall portion 13a of the case 13 is present on the other axial end side of the stator 22. The portion of the wall portion 13a facing the protrusion 221a is formed in a boss shape, and a bolt hole 13aa is provided in this portion. The bolt 50 is inserted into the protrusion 221a and tightened into the bolt hole 13aa, thereby fixing the wall portion 13a. In this way, the stator 22 is bolted to the case 13 at the wall portion 13a. A plurality of bolt holes 13aa are provided corresponding to the protrusions 221a or the through holes 221aa. The protrusions 221a correspond to the stator protrusions.

[0037] 1 and 2, coil 222 has coil end 222a and neutral point 222b. Coil end 222a is formed on both axial sides of stator 22. Neutral point 222b is a portion where coils of each phase, namely U-phase, V-phase, and W-phase, that make up coil 222 are bundled together, and coil 222 forms neutral point 222b at one end and is connected to connector terminal 60 at the other end.

[0038] The connector terminal 60 has a terminal 60u, a terminal 60v, and a terminal 60w, and is electrically connected to the stator 22. A U-phase coil is connected to the terminal 60u, a V-phase coil is connected to the terminal 60v, and a W-phase coil is connected to the terminal 60w.

[0039] 1 and 2, the neutral point 222b and the head 50a of the bolt 50 are disposed on one axial end side of the stator 22. Because the one axial 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, there is no restriction on the axial space of the unit 100 on the one axial end side that is caused by the wall portion 13a on the other axial end side.

[0040] For this reason, in the unit 100, the neutral point 222b is disposed on one axial end side of the stator 22. This allows for effective use of the axial space of the unit 100 on one axial end side of the stator 22. Therefore, compared to when the neutral point 222b is disposed on the other axial end side of the stator 22, an increase in the size of the unit 100 due to the protrusion of the coil 222 at the neutral point 222b is suppressed. As a result, the layout flexibility of the unit 100 is improved at least in the axial direction.

[0041] As shown in FIG. 2, the neutral point 222b is offset from the head 50a in the axial direction. In other words, the neutral point 222b does not overlap with the head 50a in the axial direction. Therefore, there is no need for a space corresponding to the thickness of the head 50a or an insulating distance from the head 50a in the axial direction, and therefore there is no need for the coil 222 to protrude excessively in the axial direction. As a result, the layout flexibility of the unit 100 is improved at least in the axial direction. The neutral point 222b can be disposed so as to protrude radially outward from the rotating electric machine 20 in the axial direction, and in this embodiment, it is disposed so as to protrude slightly.

[0042] Neutral point 222b is arranged to avoid region R between protrusion 221a and rotor 21 when viewed in the axial direction. Although one region R is illustrated in Fig. 2, region R exists for each of multiple protrusions 221a. Region R is defined by the base of protrusion 221a in stator core 221 (the radially inner boundary portion of protrusion 221a defined by the outer diameter of the circular portion of stator 22) and the outer periphery of rotor 21 when viewed in the axial direction.

[0043] Region R is defined as a region between the base of protrusion 221a and the center of rotor 21 as viewed in the axial direction, and is shown as a surface surrounded by a dashed line as viewed in the axial direction, as shown in Fig. 2. Such region R can be defined as a region defined between two lines that are parallel to a line including the centers of rotor 21 and through hole 221aa as viewed in the axial direction, and that include both circumferential end positions of protrusion 221a.

[0044] The reason why the neutral point 222b is arranged so as to avoid the region R when viewed in the axial direction is as follows.

[0045] To offset the neutral point 222b from the head 50a in the axial direction, the neutral point 222b can be located near the base of the protrusion 221a while avoiding the head 50a. In this case, however, the bolt 50 is located radially outward from the neutral point 222b to ensure an insulating distance between the bolt 50 and the neutral point 222b. As a result, the stator 22 inevitably expands in the radial direction.

[0046] For this reason, in the unit 100, such a situation is avoided by arranging the neutral point 222b so as to avoid the region R when viewed in the axial direction, thereby improving the layout flexibility of the unit 100 at least in the radial direction.

[0047] The housing 10 has a peripheral wall portion 13b that surrounds the rotating electric machine 20 and the first drive shaft 61 when viewed in 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 that is operatively connected downstream of the rotating electric machine 20.

[0048] Here, in a configuration in which the rotating electric machine 20 and the first drive shaft 61 are arranged in the same room surrounded by one peripheral wall portion 13b in the axial direction, there is a structurally sufficient space as follows: That is, in such a configuration, as shown in Figures 1 and 2, at one axial end side of the stator 22, there is a sufficient space on the side where the first drive shaft 61 is arranged as viewed from the center of rotation of the rotating electric machine 20, that is, the first axis AX1.

[0049] For this reason, the neutral point 222b is located between the first vertical line V1 passing through the center of rotation of the rotor 21 and the second vertical line V2 passing through the center of rotation of the first drive shaft 61, i.e., the fourth axis AX4, as viewed in the axial direction. This allows the neutral point 222b to be positioned in a manner that makes effective use of the available space, as described above, thereby preventing the neutral point 222b from increasing the size of the unit 100, and improving the layout flexibility of the unit 100.

[0050] 2, the connector terminal 60 is disposed on one axial end side of the stator 22. As a result, the neutral point 222b, the head 50a, and the connector terminal 60, which may affect the size of the unit 100 at least in the axial direction, are all concentrated on one axial end side of the stator 22. As a result, the layout flexibility of the unit 100 is improved at least in the axial direction compared to when the connector terminal 60 is disposed on the other axial end side of the stator 22.

[0051] 2 and 3, the unit 100 contains oil OL. The oil OL is supplied, for example, from outside the housing 10 to the rotating electrical machine 20 in the case 13, and lubricates the rotating electrical machine 20. A portion of the oil OL supplied to the rotating electrical 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 used by circulating inside and outside the housing 10.

[0052] The case 13 has a through hole 13c. The through hole 13c is formed in the portion of the case 13 below the first shaft AX1 and the fourth shaft AX4 in the direction of gravity, and connects the inside of the second cover 12 with the inside of the case 13. Therefore, oil OL in the case 13 can flow into the second cover 12 through the through hole 13c as shown by the arrow, and is also used to lubricate the differential gear 40. An oil reservoir is formed in each of the second cover 12 and the case 13 in the portion below in the direction of gravity. The oil reservoir of the unit 100 is also formed in the first cover 11.

[0053] 2, the neutral point 222b is located in a position where it is submerged in oil at least while the vehicle is running. The neutral point 222b is located in this manner by being submerged in oil (buried in oil OL) in the oil reservoir and being located below the oil level LV in the oil reservoir in the direction of gravity. The oil level LV is the oil level in the oil reservoir in the housing 10 in a steady circulation state, and is the same oil level height as the oil reservoirs in the first cover 11, the second cover 12, and the case 13.

[0054] The steady circulation state is a state in which the circulation of oil OL is steady, and when oil circulation is performed using a pump, for example, the steady circulation state is a state in which the oil level LV stabilizes while the pump is operating. Oil circulation may also be performed by stirring up the oil OL using a rotating member such as a gear inside the housing 10. In this case, the steady circulation state is a state in which the oil level LV stabilizes while the rotating member is rotating.

[0055] The oil level LV is set to a height at which the stator 22 is immersed in oil OL in a steady circulation state, but the oil OL does not enter the air gap AG, which is the gap between the rotor 21 and stator 22 of the rotating electrical machine 20. This is because, while the rotational resistance of the rotating electrical machine 20 increases rapidly when the oil OL enters the air gap AG, it is desirable to cool the stator 22.

[0056] For this reason, 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 that overlaps with the through hole 13c as viewed in the axial direction in a steady circulation state.

[0057] The steady circulation state is established at least while the vehicle is running, and the neutral point 222b is submerged in oil, for example, in the steady circulation state while the vehicle is running. In other words, while the vehicle is running, the rotating electric machine 20 is in operation, and at the neutral point 222b where the coils of each phase are bundled, the coils 222 are particularly likely to heat up while the rotating electric machine 20 is in operation. For this reason, by arranging the neutral point 222b so that it is submerged in oil while the vehicle is running, the temperature rise at the neutral point 222b can be appropriately suppressed, which is preferable.

[0058] Regardless of whether the vehicle is in a steady circulation state or not, the neutral point 222b can be positioned at a position lower than the lowered oil level if the oil level in the oil reservoir drops while the vehicle is running, or can be positioned at a position lower than the tilted oil level if the oil level tilts while the vehicle is running.

[0059] In other words, the neutral point 222b can be located at a position where it is submerged in oil while the vehicle is running, regardless of the vertical position of the oil level or the inclination of the oil level, which change while the vehicle is running. Alternatively, it is preferable that the neutral point 222b be located at a position where it is submerged in oil while the vehicle is running, regardless of changes in the oil level while the vehicle is running, including the vertical position of the oil level and the inclination of the oil level. Changes in the oil level while the vehicle is running may be within an expected range in design.

[0060] Next, the main effects of this embodiment will be described.

[0061] (1) The unit 100 has a bolt 50 and a rotating electric machine 20. The rotating electric machine 20 has a rotor 21 and a stator 22 that surrounds the outer periphery of the rotor 21. The stator 22 has a protrusion 221a that protrudes radially outward from the outer periphery of the stator 22. The bolt 50 is inserted into the protrusion 221a in a direction from one axial end side of the stator 22 to the other axial end side. The neutral point 222b of the stator 22 and the head 50a of the bolt 50 are located on the one axial end side of the stator 22. When viewed in the axial direction, the neutral point 222b of the stator 22 is offset from the head 50a of the bolt 50.

[0062] This configuration allows for effective use of the axial space of the unit 100 at one axial end of the stator 22. This prevents the unit 100 from becoming larger in size due to the coil 222 protruding from the neutral point 222b. As a result, the layout flexibility of the unit 100 can be improved at least in the axial direction compared to when the neutral point 222b is located at the other axial end of the stator 22. Furthermore, because the neutral point 222b is located at a position offset from the head 50a when viewed in the axial direction, there is no need for the coil 222 to protrude excessively in the axial direction due to the head 50a. Therefore, this also allows for improved layout flexibility of the unit 100 at least in the axial direction.

[0063] (2) In the unit 100, the neutral point 222b of the stator 22 is disposed so as to avoid the region R between the protrusion 221a and the rotor 21 when viewed in the axial direction. This configuration makes it possible to avoid a situation in which the bolt 50 needs to be positioned radially outwardly from the neutral point 222b in order to ensure an insulation distance between the bolt 50 and the neutral point 222b. This improves the layout flexibility of the unit 100 at least in the radial direction.

[0064] (3) The unit 100 has a housing 10 that houses the rotating electric machine 20 and a first drive shaft 61 that is operatively connected downstream 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 in the axial direction. When viewed in the axial direction, the neutral point 222b is located between a first vertical line V1 that passes through the center of rotation of the rotor 21 and a second vertical line V2 that passes through the center of rotation of the first drive shaft 61.

[0065] With this configuration, the rotating electric machine 20 and the first drive shaft 61 are arranged in the same room surrounded by a single peripheral wall portion 13b in the axial view, and therefore the neutral point 222b can be arranged in a manner that effectively utilizes the available space at one axial end of the stator 22. This improves the layout flexibility of the unit 100.

[0066] (4) The unit 100 is used in a vehicle and includes oil OL. The neutral point 222b is located in a position where it is submerged in oil at least while the vehicle is running. With this configuration, the temperature rise at the neutral point 222b, which is particularly susceptible to heat up while the rotating electric machine 20 is running, can be appropriately suppressed by cooling with the oil OL.

[0067] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments. [Explanation of symbols]

[0068] 10. Housing 13 cases 13b Peripheral wall part 20 Rotating Electric Machine 21 rotor 22 Stator 221 Stator Core 221a Protrusion (stator protrusion) 222 Coil 222a coil end 222b Neutral point 30 Reduction mechanism 40 Differential gear 50 volts 50a head 60 Connector terminal 61 First drive shaft (shaft) 100 units LV Oil Level Office Lady Oil R area V1 1st vertical line V2 2nd vertical line

Claims

1. a bolt and a rotating electric machine, The rotating electric machine includes a rotor and a stator surrounding the outer periphery of the rotor, the stator has a stator protrusion that protrudes radially outward from an outer periphery of the stator, the bolt is inserted into the stator protrusion in a direction from one axial end side to the other axial end side of the stator, a neutral point of the stator and a head of the bolt are disposed on one axial end side of the stator, A unit in which the neutral point of the stator is offset from the head of the bolt when viewed in the axial direction.

2. 2. The unit of claim 1, 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. unit.

3. 2. The unit of claim 1, a housing that accommodates the rotating electric machine; a shaft operatively connected downstream of the rotating electrical machine; and the housing has a peripheral wall portion that surrounds the rotating electric machine and the shaft when viewed in the axial direction, When viewed in 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. unit.

4. A unit according to any one of claims 1 to 3, Used in vehicles, The neutral point is disposed at a position that is submerged in oil at least while the vehicle is running. unit.

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