Drive unit

Abstract

To improve the cooling efficiency of the drive unit using coolant. [Solution] The drive unit comprises a case, a shaft rotatably supported by the case, a rotor that rotates with the shaft, a stator provided on the outer circumference of the rotor, and a coil end provided at the axial end of the stator and protruding axially from the end face of the rotor. The drive unit comprises a cooling device that supplies coolant to the coil end from above when installed in a vehicle, and a shielding plate positioned between the shaft and the coil end in a region above the axis of the shaft, which suppresses airflow in the direction of rotation of the rotor. The shielding plate is positioned upstream of the rotor in the direction of rotation from the coolant supply path that flows from the coil end to the shaft.

Description

Technical Field

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[0001] The present invention relates to a drive device.

Background Art

[0002] Patent Document 1 discloses a rotating electric machine as a drive device. The rotating electric machine includes a rotor, a stator core, and a cooling device that supplies a coolant to the coil ends of the stator core from above.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In this rotating electric machine, the coolant supplied to the coil ends falls downward and is recovered after cooling the supply location. Therefore, it has been difficult to improve the cooling efficiency by the coolant.

[0005] The present invention has been made in view of the above problems, and an object thereof is to improve the cooling efficiency of a drive device by a coolant.

Means for Solving the Problems

[0006] According to one aspect of the present invention, a vehicle drive system is provided, comprising: a case; a shaft rotatably supported by the case; a rotor that rotates with the shaft; a stator provided on the outer circumference of the rotor; a coil end provided at the axial end of the stator and protruding axially from the end face of the rotor; a cooling device that supplies coolant to the coil end from above when the vehicle is installed; and a shielding plate positioned between the shaft and the coil end in a region above the axis of the shaft and suppressing airflow in the direction of rotation of the rotor, wherein the shielding plate is positioned upstream of the rotor in the direction of rotation from the supply path of the coolant flowing from the coil end to the shaft. [Effects of the Invention]

[0007] According to one aspect of the present invention, the coolant supplied from the cooling device to the coil end of the stator cools the supply point and then flows from the coil end toward the shaft. A shielding plate is positioned upstream of the rotor's rotational direction from the coolant supply path toward the shaft to suppress airflow toward the rotor's rotational direction.

[0008] Therefore, the airflow generated by the rotor's rotation is suppressed from flowing into the supply path. As a result, the coolant flow from the coil end is suppressed by the airflow generated by the rotor's rotation, making it possible to flow the coolant supplied from the cooling device to the coil end onto the shaft regardless of the strength of the generated airflow.

[0009] The coolant supplied to the shaft then splashes towards the coil ends surrounding the rotating shaft. The coil ends are then cooled again by the splashed coolant.

[0010] In this way, the coolant that flows from the coil end after cooling the supply point of the coil end is reused to cool the coil end by splashing towards the coil end. Therefore, it is possible to improve the cooling efficiency of the drive unit using the coolant. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a cross-sectional view of a drive device according to an embodiment of the present invention, viewed from the side. [Figure 2] Figure 2 is a cross-sectional view of a drive device according to an embodiment of the present invention, viewed from the front. [Figure 3] Figure 3 is a cross-sectional view of a drive device according to a first modified embodiment of the present invention, viewed from the side. [Figure 4] Figure 4 is a cross-sectional view of a drive device according to a first modified embodiment of the present invention, as seen from the front. [Figure 5] Figure 5 is a cross-sectional view of a drive device according to a second modified embodiment of the present invention, viewed from the side. [Figure 6] Figure 6 is a cross-sectional view of a drive device according to a second modified embodiment of the present invention, as seen from the front. [Figure 7] Figure 7 is a cross-sectional view of a drive device according to a third modified embodiment of the present invention, viewed from the side. [Figure 8] Figure 8 is a cross-sectional view of a drive device according to a third modified embodiment of the present invention, as seen from the front. [Modes for carrying out the invention]

[0012] (Embodiment) The drive device 10 according to an embodiment of the present invention will be described below with reference to the attached drawings.

[0013] Figure 1 is a cross-sectional view of the drive unit 10 from the side. Figure 2 is a cross-sectional view of the drive unit 10 from the front. Figures 1 and 2 show the drive unit 10 installed in the vehicle 12.

[0014] As shown in FIGS. 1 and 2, the drive device 10 is installed on the vehicle body 14 of the vehicle 12. Examples of the vehicle 12 on which the drive device 10 is installed include an electric vehicle. The drive device 10 drives drive wheels (not shown) using electric power supplied from a power storage device (not shown).

[0015] The drive device 10 includes a case 20, a shaft 22 rotatably supported by the case 20, a rotor 24 that rotates together with the shaft 22, and a stator 26 provided on the outer periphery of the rotor 24. Further, the drive device 10 includes a coil end 30 provided at an axial end of the stator 26 and protruding in the axial direction J from a rotor end surface 24A (see FIG. 1) that is an end surface of the rotor 24.

[0016] Furthermore, the drive device 10 includes a cooling device 34 that supplies a coolant 32 to the coil end 30 from above U of the coil end 30 in the vehicle installation state. The drive device 10 also includes a shielding plate 40 disposed between the shaft 22 and the coil end 30 in a region above U of the axis 36 of the shaft 22 and suppressing an air flow 38 in the rotational direction K of the rotor 24.

[0017] (Case) The case 20 is formed, for example, in a rectangular shape. A front support hole 52 is formed in the front surface 50 of the case 20. A front bearing 54 is mounted in the front support hole 52. A rear support hole 58 is formed in the rear surface 56 of the case 20. A rear bearing 60 is mounted in the rear support hole 58.

[0018] A bottom support piece 64 extends upward U from the bottom surface 62 of the case 20 (see FIG. 2). A left side support piece 68 extends downward as it extends inward from the left side surface 66 of the case 20. A right side support piece 72 extends downward as it extends inward from the right side surface 70 of the case 20.

[0019] (Shaft) The shaft 22 is formed in a cylindrical shape. The shaft 22 is located in the center of the case 20. The shaft 22 extends so as to penetrate the front surface 50 and the rear surface 56 of the case 20.

[0020] The front end of the shaft 22 is rotatably supported on the front surface 50 via a front bearing 54. The rear end of the shaft 22 is rotatably supported on the rear surface 56 via a rear bearing 60. As a result, the shaft 22 is rotatably supported on the case 20.

[0021] (Rotor) The rotor 24 is formed in a cylindrical shape. A shaft 22 is fixed through the center of the rotor 24. This allows the rotor 24 to rotate together with the shaft 22.

[0022] The rotor 24 is equipped with, for example, permanent magnets (not shown). The permanent magnets receive magnetic force from the stator 26. As a result, a rotational force is generated in the rotor 24 in the rotational direction K (see Figure 2).

[0023] The rotor 24 rotates in the forward direction (CW) when the vehicle 12 is moved forward. The rotor 24 also rotates in the reverse direction (CCW) when the vehicle 12 is moved backward.

[0024] (Stator) The stator 26 is formed in a cylindrical shape. The stator 26 is provided on the outer circumference of the rotor 24 and surrounds the rotor 24.

[0025] The stator 26 has a bottom fixing portion 80 that extends toward the bottom support piece 64. The bottom fixing portion 80 is fixed to the bottom support piece 64 by bolts B. The stator 26 has a left fixing portion 82 that extends toward the left side support piece 68. The left fixing portion 82 is fixed to the left side support piece 68 by bolts B. The stator 26 has a right fixing portion 84 that extends toward the right side support piece 72. The right fixing portion 84 is fixed to the right side support piece 72 by bolts B.

[0026] The stator 26 has multiple teeth (not shown). A coil (not shown) is formed around each tooth by winding (not shown). Power is supplied to the coil via a busbar 316 (see Figure 6). When power is supplied, the coil energizes the teeth. The energized teeth generate a magnetic force toward the rotor 24.

[0027] (Coil end) The stator 26 has coil ends 30 protruding from the stator end face 26A (see Figure 1) on the front 50 side of the case 20. The coil ends 30 protruding toward the front 50 side of the case 20 protrude axially J further than the rotor end face 24A located on the front 50 side of the rotor 24. The stator 26 also has coil ends 30 protruding from the stator end face 26A on the rear 56 side of the case 20. The coil ends 30 protruding toward the rear 56 side of the case 20 protrude axially J further than the rotor end face 24A located on the rear 56 side of the rotor 24.

[0028] The coil end 30 is a part of the winding (not shown) wound around each tooth and consists of a portion that protrudes from the stator 26. The coil end 30 generates heat when energized.

[0029] (cooling device) The cooling device 34 (see Figure 1) includes a circulation pipe 90 for circulating the coolant 32 in the case 20, a pump 92 provided on the circulation pipe 90, and a supply pipe 94 from which the coolant 32 is supplied from the circulation pipe 90. The coolant 32 is composed of, for example, lubricating oil.

[0030] One end of the circulation pipe 90 is inserted into the case 20. The end opening 90A that opens at one end of the circulation pipe 90 opens at the bottom of the case 20. The other end of the circulation pipe 90 is connected to the supply pipe 94.

[0031] The supply pipe 94 extends along the top surface 100 of the case 20 from the rear surface 56 to the front surface 50. The supply pipe 94 is positioned above the shaft 22 U. The supply pipe 94 has a spray nozzle 102 (see Figure 2) that opens toward the coil end 30 and is formed above the coil end 30.

[0032] Pump 92 draws up the coolant 32 stored at the bottom of case 20 through the end opening 90A and sends it to supply pipe 94. Supply pipe 94 sprays the coolant 32 from the spray nozzle 102 toward coil end 30. Coil end 30 is cooled by the coolant 32 sprayed from above U.

[0033] The coolant 32 that has cooled the coil end 30 drips from the coil end 30 towards the shaft 22. Between the coil end 30 and the shaft 22, a supply path 106 for the coolant 32 is formed, extending along a straight line L connecting the center of the nozzle 102 of the supply pipe 94 and the axis 36 of the shaft 22. The straight line L extends in the vertical direction V.

[0034] (shielding plate) The shielding plate 40 (see Figure 1) extends from the front surface 50 toward the rotor 24. The shielding plate 40 is formed in the shape of a rectangular plate. The base end of the shielding plate 40 is supported by triangular plate-shaped ribs 110 that extend from the front surface 50.

[0035] The shielding plate 40 is positioned in a region U above the axis 36 of the shaft 22. The shielding plate 40 is positioned between the shaft 22 and the coil end 30. As a result, the shielding plate 40 suppresses the flow of air 38 that is generated in the rotational direction K between the coil end 30 and the shaft 22 as the rotor 24 rotates, for example.

[0036] The shielding plate 40 is positioned upstream of the rotor 24 in the direction of rotation from the supply path 106 of the coolant 32 that flows from the coil end 30 toward the shaft 22.

[0037] The rotation direction K of the rotor 24 (see Figure 2) differs depending on the direction of travel of the vehicle 12. When the vehicle 12 moves forward, the rotor 24 rotates in the forward direction, so the upstream side of the rotation direction is the upstream side of the forward rotation direction CW. When the vehicle 12 moves backward, the rotor 24 rotates in the reverse direction, so the upstream side of the rotation direction is the upstream side of the reverse rotation direction CCW.

[0038] In this embodiment, the shielding plate 40 is composed of a forward-moving shielding plate 120 positioned upstream of the supply path 106 in the forward rotation direction CW, and a backward-moving shielding plate 122 positioned upstream of the supply path 106 in the reverse rotation direction CCW.

[0039] In this embodiment, the case in which the shielding plate 40 is composed of a forward-facing shielding plate 120 and a reverse-facing shielding plate 122 will be described. However, even if the shielding plate 40 is composed of only the forward-facing shielding plate 120 or only the reverse-facing shielding plate 122 in order to reduce costs, the effects described later can be obtained in each direction of travel.

[0040] Here, the rotor 24 rotates at a higher speed when the vehicle 12 is moving forward than when it is moving backward. As a result, the airflow 38 generated by the rotation of the rotor 24 is faster when the vehicle 12 is moving forward than when it is moving backward.

[0041] Therefore, in order to obtain an airflow suppression effect while keeping costs down, if only one shielding plate 40 is used, it is desirable that the shielding plate 40 be a forward-facing shielding plate 120 positioned on the upstream side in the direction of rotation when the rotor 24 rotates while the vehicle 12 is moving forward.

[0042] Furthermore, the shielding plate 40 extends vertically in the direction V between the coil end 30 and the shaft 22. This allows the shielding plate 40 to be positioned closer to the supply path 106 over its entire length compared to when it is positioned at an angle between the coil end 30 and the shaft 22. Therefore, by extending the shielding plate 40 vertically in the direction V, it is possible to enhance the airflow suppression effect of the shielding plate 40.

[0043] Furthermore, the shielding plate 40 has a length such that its lower end on the shaft 22 side reaches a horizontal line 126 that passes through the axis 36 of the shaft 22. This suppresses the inflow of the airflow 38 flowing in the rotational direction K into the supply path 106 above U on the side of the axis 36 of the shaft 22.

[0044] (Mechanism of Action and Effects) The main effects and advantages of the drive unit 10 configured as described above will be summarized below.

[0045] (1) The drive unit 10 is the drive unit 10 of the vehicle 12. The drive unit 10 comprises a case 20, a shaft 22 rotatably supported by the case 20, a rotor 24 that rotates with the shaft 22, and a stator 26 provided on the outer circumference of the rotor 24. The drive unit 10 is provided with a coil end 30 at the axial end of the stator 26 and protruding axially J from the rotor end face 24A, which is the end face of the rotor 24. The drive unit 10 is provided with a cooling device 34 that supplies coolant 32 to the coil end 30 from above U when the vehicle is installed. The drive unit 10 is provided with a shielding plate 40 that is positioned between the shaft 22 and the coil end 30 in a region above U above the axis 36 of the shaft 22 and suppresses the airflow 38 in the rotation direction K of the rotor 24. The shielding plate 40 is positioned upstream of the rotor 24 in the direction of rotation from the supply path 106 of the coolant 32 that flows from the coil end 30 toward the shaft 22.

[0046] According to this embodiment, the coolant 32 supplied from the cooling device 34 to the coil end 30 of the stator 26 cools the supply point and then flows from the coil end 30 toward the shaft 22. A shielding plate 40 is positioned upstream of the rotor 24 in the direction of rotation from the supply path 106 of the coolant 32 flowing toward the shaft 22, in order to suppress the airflow 38 toward the direction of rotation K of the rotor 24.

[0047] Therefore, the airflow 38 generated by the rotation of the rotor 24 is suppressed from flowing into the supply path 106. As a result, the coolant 32 flowing from the coil end 30 is suppressed from lateral flow caused by the airflow 38 generated by the rotation of the rotor 24 (the airflow 38 generated by the rotation of the rotor 24 flows in a direction along the horizontal line 126 above the shaft 22. This horizontal displacement of the coolant 32 due to the airflow 38 is called lateral flow), so that regardless of the strength of the generated airflow 38, the coolant 32 supplied from the cooling device 34 to the coil end 30 can be dripped onto the shaft 22.

[0048] The coolant 32 supplied to the shaft 22 then hits the rotating shaft 22 and, for example, is scattered toward the coil end 30 surrounding the shaft 22 by the centrifugal force of the shaft 22. The coil end 30 is then cooled again by the scattered coolant 32.

[0049] In this way, the coolant 32 that flows out of the coil end 30 after cooling the supply point of the coil end 30 is scattered towards the coil end 30 by the shaft 22 and reused to cool the coil end 30. Therefore, it is possible to increase the cooling efficiency of the drive unit 10 by the coolant 32.

[0050] In particular, when the rotor 24 rotates at high speed, the coil end 30 becomes hot, while the airflow 38 generated by the rotation of the rotor 24 becomes faster. Even in such cases, the lateral flow of the coolant 32 flowing from the coil end 30 toward the shaft 22 is suppressed by the shielding plate 40. For this reason, the effect of the shielding plate 40 becomes more pronounced when the rotor 24 rotates at high speed.

[0051] (2) The shielding plate 40 is positioned on the upstream side in the direction of rotation when the rotor 24 rotates while the vehicle 12 is moving forward.

[0052] In this embodiment, when the vehicle is moving forward, the rotor 24 rotates at a higher speed than when the vehicle is moving backward, and the airflow 38 generated by the rotation of the rotor 24 becomes faster. The shielding plate 40 can suppress the inflow of such airflow 38 into the supply path 106.

[0053] Furthermore, when the vehicle moves forward, the rotor 24 rotates at high speed, which increases the amount of heat generated by the coil. Therefore, the drive unit 10 can suppress the airflow 38 generated by the high-speed rotating rotor 24, thereby promoting the cooling of the coil end 30, which tends to become hot due to high-speed rotation, and enhancing the cooling effect of the coolant 32.

[0054] Thus, by configuring the drive unit 10 with only a forward-facing shielding plate 120, which is positioned on the upstream side in the rotational direction when the vehicle is moving forward, it is possible to improve the cooling effect when the vehicle is moving forward, which tends to generate heat, while also reducing costs.

[0055] (3) The shielding plate 40 extends in the vertical direction V.

[0056] In this embodiment, the shielding plate 40, which is positioned between the coil end 30 and the shaft 22, extends in the vertical direction V. Compared to the case where it is positioned at an angle, this makes it possible to position the shielding plate 40 in close proximity along the supply path 106 over its entire length.

[0057] Therefore, the effect of the shielding plate 40 in suppressing the airflow 38 can be enhanced, making it possible to improve the effect of suppressing the lateral flow of the coolant 32 caused by the airflow 38 generated by the rotation of the rotor 24. As a result, the drive unit 10 can further improve the cooling efficiency of the coolant 32.

[0058] (5) The shielding plate 40 has a length such that the end on the shaft 22 side reaches the horizontal line 126 that passes through the axis 36 of the shaft 22.

[0059] In this embodiment, the shielding plate 40 reaches a horizontal line 126 that passes through the axis 36 of the shaft 22, making it possible to suppress the inflow of airflow 38 flowing in the rotational direction K into the supply path 106 above the axis 36 of the shaft 22 (U side). As a result, the drive unit 10 can further improve the cooling efficiency of the coolant 32.

[0060] (First torture) The following describes a drive device 200 according to a first modified embodiment of the present invention. In the first modified embodiment, parts that are the same as or equivalent to those in the above embodiment are denoted by the same reference numerals and their descriptions are omitted, while only the different parts are described.

[0061] Figure 3 is a cross-sectional view of the drive device 200 according to the first modified example, viewed from the side. Figure 4 is a cross-sectional view of the drive device 200 according to the first modified example, viewed from the front.

[0062] As shown in Figures 3 and 4, the drive device 200 according to the first modified example differs from the embodiment described above in the configuration of the shielding plate 210. The shielding plate 210 is positioned such that its upper end 212, which is the end on the coil end 30 side, is located upstream of the rotor 24 in the rotational direction than its lower end 214, which is the end on the shaft 22 side.

[0063] To explain in more detail, the shielding plate 210 is formed in the shape of a rectangular plate. An extension portion 220 extends from the shielding plate 210. A circular ring-shaped fixing portion 222 is formed at the tip of the extension portion 220. A bolt B is inserted through the fixing portion 222. The fixing portion 222 is fastened together with the left fixing portion 82 of the stator 26 to the left side support piece 68 of the case 20 by the bolt B.

[0064] The extension portion 202, which extends from the fixed portion 222, extends toward the shaft 22 from the fixing point by the left side support piece 68. The shielding plate 210 provided at the tip of the extension portion 202 is positioned between the shaft 22 and the coil end 30 in a region above the axis 36 of the shaft 22, and suppresses the airflow 38 in the rotation direction K of the rotor 24.

[0065] The shielding plate 210 is positioned upstream of the rotor 24 in the direction of rotation from the supply path 106 for the coolant 32 that flows from the coil end 30 towards the shaft 22. In this modified example, the shielding plate 210 is positioned upstream of the rotor 24 in the direction of rotation when the vehicle 12 is moving forward.

[0066] Since the rotor 24 (see Figure 4) rotates in the forward direction when the vehicle 12 is moved forward, the shielding plate 210 is positioned upstream of the supply path 106 in the forward rotation direction CW.

[0067] In other words, in Figure 4, the shielding plate 210 is positioned in a region above the horizontal line 126 passing through the axis 36 of the shaft 22, and to the left of the straight line L connecting the center of the nozzle 102 of the supply pipe 94 and the axis 36 of the shaft 22.

[0068] Furthermore, the shielding plate 210 is positioned at an angle with respect to the straight line L such that the upper end 212 on the coil end 30 side is located upstream in the forward rotation direction CW compared to the lower end 214 on the shaft 22 side.

[0069] The shielding plate 210 (see Figure 4) has a length such that its lower end 214 on the shaft 22 side reaches the horizontal line 126 through which the axis 36 of the shaft 22 passes. In Figure 4, the corner of the tip of the shielding plate 210 is in contact with the horizontal line 126.

[0070] (Mechanism of Action and Effects) In this modified example, the same or equivalent parts as those in the above embodiment will produce the same effects and advantages as in the above embodiment.

[0071] (4) In the drive unit 200, the shielding plate 210 is positioned such that its upper end 212, which is the end on the coil end 30 side, is located upstream of the rotor 24 in the rotational direction than its lower end 214, which is the end on the shaft 22 side.

[0072] According to this modified example, the shielding plate 210 is inclined away from the coolant supply path 106 as it moves from the lower end 214 on the shaft 22 side to the upper end 212 on the coil end 30 side. As a result, the space on the supply path 106 side widens as it moves towards the coil end 30 side.

[0073] Therefore, the cooling liquid 32 scattered from the shaft 22 is prevented from being blocked by the shielding plate 210 or the extension portion 220, and the adhesion of the cooling liquid 32 to the coil end 30 is promoted, making it possible to further improve the cooling efficiency of the coil end 30.

[0074] Furthermore, the drive unit 200 of this modified example includes only a shielding plate 210 positioned on the upstream side in the direction of rotation when the rotor 24 rotates while the vehicle 12 is moving forward.

[0075] Therefore, the drive unit 200 can be made more cost-effective compared to the case where shielding plates 210 are provided on both the upstream side of the rotor 24's rotation direction during forward movement and the upstream side of the rotor 24's rotation direction during reverse movement.

[0076] (Second variation) The following describes a drive device 300 according to a second modified embodiment of the present invention. In the second modified embodiment, parts that are the same as or equivalent to those in the above embodiment are denoted by the same reference numerals and their descriptions are omitted, while only the different parts are described.

[0077] Figure 5 is a cross-sectional view of the drive unit 300 according to the second modified example, viewed from the side. Figure 6 is a cross-sectional view of the drive unit 300 according to the second modified example, viewed from the front.

[0078] As shown in Figures 5 and 6, the drive unit 300 according to the second modified example differs from the above embodiment mainly in the fixing structure of the stator 26 to the case 20 and the fixing position of the shielding plate 310. The shielding plate 310 of the drive unit 300 according to the second modified example is supported by a busbar mounting portion 312 to which a busbar (not shown) for supplying power to the stator 26 is attached.

[0079] To explain in more detail, the stator 26 is fitted inside the inner housing 302. The inner housing 302 is press-fitted into the case 20 and fixed to the case 20. For the sake of explanation, the case 20 is shown as rectangular, but it may also be cylindrical.

[0080] The inner housing 302 is provided with a busbar mounting section 312. The busbar mounting section 312 relays the windings of the coil wound on the teeth to the busbar 316. Power is supplied to the coil of the stator 26 from the busbar 316 attached to the busbar mounting section 312.

[0081] A shielding plate 310 is attached to the busbar mounting section 312. The shielding plate 310 (see Figure 6) consists of a forward shielding plate 320 positioned upstream of the supply path 106 in the forward rotation direction CW, and a backward shielding plate 322 positioned upstream of the supply path 106 in the reverse rotation direction CCW.

[0082] The forward-moving shielding plate 320 is formed in the shape of a rectangular plate. A forward-moving extension portion 330 extends from the forward-moving shielding plate 320. A circular ring-shaped forward-moving fixing portion 332 is formed at the tip of the forward-moving extension portion 330. A bolt B is inserted through the forward-moving fixing portion 332. The bolt B fixes the forward-moving fixing portion 332 to the busbar mounting portion 312 and also fixes the busbar mounting portion 312 to the inner housing 302 (see Figure 5).

[0083] The retraction shielding plate 322 is formed in the shape of a rectangular plate. A retraction extension portion 340 extends from the retraction shielding plate 322. A circular ring-shaped retraction fixing portion 342 is formed at the tip of the retraction extension portion 340. A bolt B is inserted through the retraction fixing portion 342. The bolt B fixes the retraction fixing portion 342 to the busbar mounting portion 312 and also fixes the busbar mounting portion 312 to the inner housing 302.

[0084] The forward-moving shielding plate 320 and the reverse-moving shielding plate 322 are positioned between the shaft 22 and the coil end 30 in a region above the axis 36 of the shaft 22, and suppress the airflow 38 in the rotation direction K of the rotor 24. The forward-moving shielding plate 320 and the reverse-moving shielding plate 322 extend vertically in the direction V between the shaft 22 and the coil end 30.

[0085] Furthermore, the forward-moving shielding plate 320 and the backward-moving shielding plate 322 have a length such that the lower end 214 on the shaft 22 side reaches the horizontal line 126 through which the axis 36 of the shaft 22 passes.

[0086] (Mechanism of Action and Effects) In this modified example, the same or equivalent parts as those in the above embodiment will produce the same effects and advantages as in the above embodiment.

[0087] (6) In the drive unit 300, the shielding plate 310 is supported by a busbar mounting portion 312 to which a busbar for supplying power to the stator 26 is attached.

[0088] According to this modified example, the shielding plate 310 is supported by the busbar mounting portion 312. Therefore, the drive unit 300 can fix the shielding plate 310 without providing a separate fixing point for the shielding plate 310, thus enabling cost reduction.

[0089] (Third variation) The following describes a drive device 400 according to a third modified embodiment of the present invention. In the third modified embodiment, parts that are the same as or equivalent to those in the second modified embodiment are denoted by the same reference numerals and their descriptions are omitted; only the different parts will be described.

[0090] Figure 7 is a cross-sectional view of the drive unit 400 according to the third modified example, viewed from the side. Figure 8 is a cross-sectional view of the drive unit 400 according to the third modified example, viewed from the front.

[0091] As shown in Figures 7 and 8, the drive device 400 according to the third modified example has a different configuration of shielding plate 410 compared to the second modified example.

[0092] To explain in more detail, the drive unit 400 of this modified example includes only a shielding plate 410 positioned on the upstream side in the direction of rotation when the rotor 24 rotates while the vehicle 12 is moving forward.

[0093] The shielding plate 410 is formed in a rectangular shape. An extension portion 202 extends from the shielding plate 410. A circular ring-shaped fixing portion 222 is formed at the tip of the extension portion 202. A bolt B is inserted through the fixing portion 222. The fixing portion 222 is fixed by the bolt B to the shielding plate fixing point 420 (see Figure 8) set on the end face of the inner housing 302.

[0094] The shielding plate 410 is positioned between the shaft 22 and the coil end 30 in a region above the axis 36 of the shaft 22, and suppresses the airflow 38 in the rotation direction K of the rotor 24.

[0095] The shielding plate 410 is positioned upstream of the rotor 24 in the direction of rotation from the supply path 106 for the coolant 32 flowing from the coil end 30 towards the shaft 22. In this modified example, the shielding plate 410 is positioned upstream of the rotor 24 in the direction of rotation when the vehicle 12 is moving forward. Since the rotor 24 rotates in the forward direction when the vehicle 12 is moving forward, the shielding plate 410 is positioned upstream of the supply path 106 in the forward rotation direction CW.

[0096] In other words, in Figure 8, the shielding plate 410 is positioned in a region above the horizontal line 126 passing through the axis 36 of the shaft 22, and to the left of the straight line L connecting the center of the nozzle 102 of the supply pipe 94 and the axis 36 of the shaft 22.

[0097] Furthermore, the shielding plate 410 is positioned at an angle with respect to the straight line L such that the upper end 212 on the coil end 30 side is located upstream in the forward rotation direction CW compared to the lower end 214 on the shaft 22 side.

[0098] Furthermore, the shielding plate 410 has a length such that its lower end 214 on the shaft 22 side reaches the horizontal line 126 that passes through the axis 36 of the shaft 22. In Figure 8, the corner of the tip of the shielding plate 410 is in contact with the horizontal line 126.

[0099] (Mechanism of Action and Effects) In this modified example, the same or equivalent parts as those in the above embodiment and each modified example will produce the same effects and advantages as those in the above embodiment and each modified example.

[0100] Furthermore, the shielding plate 410 is supported on the end face of the stator 26. Therefore, the drive unit 400 can fix the shielding plate 410 without providing a separate fixing point for the shielding plate 410, thus enabling cost reduction.

[0101] Although embodiments of the present invention have been described above, these embodiments only represent a part of the 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. [Explanation of Symbols]

[0102] 10,200,300,400 drive unit 12 vehicles 20 cases 22 shafts 24 rotors 24A Rotor end face 26 stata 26A Stator end face 30 coil ends 32 Coolant 34 Cooling device 36 axis 38 Airflow 40,210,310,410 Shielding plate 106 Supply routes 126 Horizontal line 312 Busbar mounting section J-axis direction K rotation direction U upward V vertical direction

Claims

1. A vehicle drive system, The case and A shaft rotatably supported in the aforementioned case, A rotor that rotates together with the aforementioned shaft, A stator is provided on the outer circumference of the rotor, A coil end is provided at the axial end of the stator and protrudes axially from the end face of the rotor, A cooling device that supplies coolant to the coil end from above when the vehicle is installed, A shielding plate is positioned between the shaft and the coil end in a region above the axis of the shaft, and is used to suppress airflow in the direction of rotation of the rotor. Equipped with, The shielding plate is positioned upstream of the rotor in the direction of rotation from the supply path of the coolant flowing from the coil end toward the shaft. Drive unit.

2. A drive device according to claim 1, The shielding plate is positioned on the upstream side in the direction of rotation when the rotor rotates while the vehicle is moving forward. Drive unit.

3. A drive device according to claim 1, The shielding plate extends in the vertical direction, Drive unit.

4. A drive device according to claim 1, The shielding plate is positioned such that the end on the coil end side is located upstream of the rotor in the rotational direction compared to the end on the shaft side. Drive unit.

5. A drive device according to claim 3 or claim 4, The shielding plate has a length such that the end on the shaft side reaches a horizontal line passing through the axis of the shaft. Drive unit.

6. A drive device according to claim 1, The shielding plate is supported by a busbar mounting portion to which a busbar for supplying power to the stator is attached. Drive unit.

Images