Drive unit

Abstract

This invention provides a technology for supplying more refrigerant to the coil ends in a drive unit. [Solution] The drive unit comprises a motor having a coil wound around a stator core, a plurality of power lines extending from the coil and each having a terminal at its end, a terminal block holding the terminals of the plurality of power lines, and a refrigerant supply port that injects refrigerant toward the coil end, which is a part of the coil that protrudes from the end face of the stator core. The terminal block comprises a main body positioned opposite the coil end and a pair of side walls extending from the main body toward the coil end. The refrigerant supply port injects refrigerant toward the coil end in the space enclosed by the main body and the pair of side walls of the terminal block.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a drive unit equipped with a motor.

Background Art

[0002] Patent Document 1 discloses a drive unit. This drive unit includes a motor and a refrigerant supply port that injects refrigerant toward the coil ends of the motor. The coil ends refer to a part of the coil wound around the stator core and protruding from the end face of the stator core.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the drive unit as described above, part of the refrigerant injected from the refrigerant supply port may bounce back at the coil ends and scatter around. Alternatively, it is assumed that the injection pressure of the refrigerant at the refrigerant supply port fluctuates, causing the refrigerant to be injected at a wide angle unintentionally. In these cases, the amount of refrigerant supplied to the coil ends may decrease, and there is a risk that the coil ends cannot be cooled sufficiently.

[0005] In view of the above, this specification provides a technology for supplying more refrigerant to the coil ends in a drive unit.

Means for Solving the Problems

[0006] The disclosures herein are embodied in a drive unit. The drive unit comprises a motor having a coil wound around a stator core, a plurality of power lines extending from the coil and each having a terminal at its end, a terminal block holding the terminals of the plurality of power lines, and a refrigerant supply port for injecting refrigerant toward the coil end, which is a part of the coil that protrudes from the end face of the stator core. The terminal block comprises a main body positioned opposite the coil end and a pair of side walls extending from the main body toward the coil end. The refrigerant supply port injects refrigerant toward the coil end in the space enclosed by the main body and the pair of side walls of the terminal block.

[0007] According to the above configuration, the refrigerant bounced back at the coil end is captured by the side wall provided on the terminal block. Alternatively, even if the refrigerant injection pressure at the refrigerant supply port becomes high and the refrigerant is unintentionally injected at a wide angle, the refrigerant injected at a wide angle is captured by the side wall. Some or all of the captured refrigerant is guided or bounced back by the side wall and supplied again to the coil end. This ensures that a large portion of the refrigerant injected from the refrigerant supply port is reliably supplied to the coil end.

[0008] In one embodiment of this technology, the main body of the terminal block may be located above the motor's rotation axis, and the pair of side walls of the terminal block may each extend downward from the main body. With this configuration, the refrigerant captured by the side walls of the terminal block is guided by its weight along the side walls to the coil end. This allows a larger amount of refrigerant to be supplied to the coil end.

[0009] In one embodiment of this technology, the refrigerant supply port may be provided on the main body of the terminal block. With this configuration, the dimensions of the drive unit can be made smaller in the direction in which the main body of the terminal block and the coil end face each other.

[0010] In the above embodiment, the main body of the terminal block may include a first refrigerant supply channel that supplies refrigerant to the refrigerant supply port, and at least one second refrigerant supply channel that branches off from the first refrigerant supply channel and extends within the main body. With this configuration, not only the coil end can be cooled, but the terminal block and the power lines held by the terminal block can also be cooled.

[0011] In the above embodiment, at least one second refrigerant supply channel may extend along the direction of arrangement of the terminal portions of the multiple power lines. This configuration allows for more effective cooling of the multiple power lines. [Brief explanation of the drawing]

[0012] [Figure 1] This is a view of the drive unit 2 of Example 1, seen from one of the coil ends 18a. [Figure 2] Figure 1 shows a cross-sectional view of the drive unit 2 of Embodiment 1, taken along line II-II. [Figure 3] This is a view of the drive unit 4 of Example 2, seen from one of the coil ends 18a. [Figure 4] Figure 3 shows a cross-sectional view of the drive unit 4 of Embodiment 2 along the line IV-IV. [Figure 5] This is a cross-sectional view of the drive unit 6 of Example 3, taken from a direction perpendicular to the direction in which the coil 18 extends. [Figure 6] Figure 5 shows a cross-section of the drive unit 6 of Embodiment 3, taken along the line VI-VI. [Modes for carrying out the invention]

[0013] (Example 1) The drive unit 2 of Embodiment 1 will be described with reference to Figures 1 and 2. The drive unit 2 of Embodiment 1 can be used as a drive source to drive the wheels in various types of electric vehicles. For example, the drive unit 2 may be installed in battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), fuel cell electric vehicles (FCEVs), etc.

[0014] As shown in Figures 1 and 2, the drive unit 2 comprises a motor 10, multiple power lines 20, a terminal block 30, and a first refrigerant supply channel 40. These components are housed within the casing 8 of the drive unit 2. The casing 8 is sealed with a refrigerant, such as lubricating oil, and is configured to cool the inside of the casing 8 by the circulation of the refrigerant. In the figures, direction UP indicates vertically upward, and direction DW indicates vertically downward. In this specification, vertically upward and vertically downward may be abbreviated as upward and downward at the ends.

[0015] The motor 10 comprises a rotor 11 and a stator 15. The rotor 11 has a shaft 12 extending along the axial direction, a rotor core 13 provided on the outer surface of the shaft 12, and a magnet 14 installed inside the rotor core 13. The rotor core 13 is made of a soft magnetic material, such as electromagnetic steel.

[0016] The stator 15 comprises a stator core 16 and coils 18 wound around the stator core 16. The coils 18 include coil ends 18a, a portion of which protrudes from the end face of the stator core 16. The specific configuration of the motor 10 is not particularly limited. For example, the motor 10 is a three-phase AC motor, and the coils 18 include three phases of coils: U, V, and W.

[0017] The plurality of power lines 20 extend from the coil 18 of the motor 10. As described above, the coil 18 includes coils of three phases, namely U, V, and W. Therefore, the plurality of power lines 20 also include power lines of three phases, namely U, V, and W. Each of the plurality of power lines 20 has a terminal portion 20a at its tip end. The terminal portion 20a is connected to the terminal block 30. The terminal portion 20a may be fixed to the terminal block 30 by, for example, bolts or the like. In addition, the plurality of power lines 20 may further include a terminal connected to the neutral point of the coil 18. The number of the plurality of power lines 20 is not particularly limited.

[0018] The terminal block 30 is configured to be connectable to a PCU (POWER CONTROL UNIT) or a power source (not shown) for supplying power to the motor 10. Thereby, the plurality of power lines 20 extending from the motor 10 are electrically connected to the PCU or the power source via the terminal block 30. The terminal block 30 includes a main body portion 32 made of an insulating material. The main body portion 32 is arranged to face the coil end 18a. A pair of side wall portions 34 are provided on the main body portion 32. The pair of side wall portions 34 extend downward toward the coil end 18a.

[0019] In the first refrigerant supply passage 40, the refrigerant 50 flows inside. A first refrigerant supply port 40a that is arranged above the coil end 18a and opens downward is provided in a part of the first refrigerant supply passage 40. The refrigerant 50 is jetted from the first refrigerant supply port 40a toward the coil end 18a. Here, the direction in which the first refrigerant supply port 40a jets the refrigerant 50 is adjusted according to the position of the coil end 18a.

[0020] The specific type and characteristics of the refrigerant 50 are not particularly limited. Although it is an example, the refrigerant 50 used in the first embodiment may be an oily liquid used for cooling a known electric motor or the like.

[0021] In Example 1, the first refrigerant supply passage 40 is arranged between the terminal block 30 and the motor 10 in the vertical direction. And the first refrigerant supply port 40a injects the refrigerant 50 toward the coil end 18a in the space surrounded by the main body portion 32 of the terminal block 30 and the pair of side wall portions 34. Thereby, the refrigerant 50 is supplied to the coil end 18a, and the coil end 18a is cooled.

[0022] A part of the refrigerant 50 injected from the first refrigerant supply port 40a may bounce back at the coil end 18a. However, the refrigerant 50 bounced back at the coil end 18a is captured by the pair of side wall portions 34 provided on the terminal block 30 without scattering to the surroundings. Alternatively, when the injection pressure of the refrigerant 50 at the first refrigerant supply port 40a becomes high, the refrigerant 50 may be injected at a wide angle unintentionally. However, even the refrigerant 50 injected at such a wide angle is captured by the pair of side wall portions 34 without scattering to the surroundings. Part or all of the captured refrigerant 50 is guided or bounced back by the side wall portion 34 and supplied to the coil end 18a again. Thereby, most of the refrigerant 50 injected from the first refrigerant supply port 40a can be surely supplied to the coil end 18a.

[0023] (Example 2) The drive unit 4 of Embodiment 2 will be described with reference to Figures 3 and 4. Compared to the drive unit 2 of Embodiment 1, the drive unit 4 of Embodiment 2 has a modified position for the first refrigerant supply passage 40. Specifically, in the drive unit 4 of Embodiment 2, as shown in Figures 3 and 4, the first refrigerant supply passage 40 is installed inside the main body 32 of the terminal block 30. The first refrigerant supply port 40a provided in the first refrigerant supply passage 40 opens toward the coil end 18a at the lower part 32a of the main body 32 of the terminal block 30. The refrigerant 50 flowing inside the first refrigerant supply passage 40 is injected downward from the first refrigerant supply port 40a. In other respects, the drive unit 4 of Embodiment 2 has the same configuration as the drive unit 2 of Embodiment 1 shown in Figures 1 and 2. Specifically, the drive unit 4 of Embodiment 2 also comprises a motor 10, a plurality of power lines 20, a terminal block 30, and a first refrigerant supply passage 40. These configurations and functions are as described in Example 1, and therefore, we will avoid repeating them here.

[0024] In the drive unit 4 of Embodiment 2, the first refrigerant supply port 40a injects refrigerant 50 toward the coil end 18a within the space enclosed by the main body 32 and the pair of side walls 34 of the terminal block 30. This ensures that a large portion of the refrigerant 50 injected from the first refrigerant supply port 40a is reliably supplied to the coil end 18a. In addition, in the drive unit 4 of Embodiment 2, the terminal block 30 and the first refrigerant supply channel 40 are integrated into a single unit. This allows the drive unit 4 to be constructed with smaller dimensions in the vertical direction where the terminal block 30 and the coil end 18a face each other. Furthermore, it is possible to save space inside the casing 8.

[0025] (Example 3) Referring to Figures 5 and 6, the drive unit 6 of Embodiment 3 will be described. Compared to the drive unit 4 of Embodiment 2, the drive unit 6 of Embodiment 3 has an additional second refrigerant supply channel 42. The second refrigerant supply channel 42 branches off from the first refrigerant supply channel 40 and extends inside the main body 32 of the terminal block 30. Although not particularly limited, the second refrigerant supply channel 42 extends along the direction of arrangement of the terminal portions 20a of the multiple power lines 20. In other respects, the drive unit 6 of Embodiment 3 has the same configuration as the drive unit 2 of Embodiment 1 shown in Figures 1 and 2. That is, the drive unit 6 of Embodiment 3 also comprises a motor 10, multiple power lines 20, a terminal block 30, a first refrigerant supply channel 40, and a first refrigerant supply port 40a. These configurations and functions are as described in Embodiment 1, and will not be described again here.

[0026] In the drive unit 6 of Embodiment 3, the first refrigerant supply port 40a injects refrigerant 50 toward the coil end 18a within the space enclosed by the main body 32 and the pair of side walls 34 of the terminal block 30. This ensures that a large portion of the refrigerant 50 injected from the first refrigerant supply port 40a is reliably supplied to the coil end 18a. In addition, in the drive unit 6 of Embodiment 3, a portion of the refrigerant 50 flowing through the first refrigerant supply channel 40 is injected downward from the first refrigerant supply port 40a. Another portion of the refrigerant 50 flowing through the first refrigerant supply channel 40 flows from the first refrigerant supply channel 40 to the second refrigerant supply channel 42. This refrigerant 50 flows through the main body 32 of the terminal block 30, thereby cooling the terminal block 30 and the multiple power lines 20 held by the terminal block 30. In particular, the second refrigerant supply channel 42 in this embodiment flows along the direction of arrangement of the terminal portions 20a of the multiple power lines 20. This effectively cools the multiple power lines 20. The refrigerant 50 that has flowed through the second refrigerant supply channel 42 is injected from a pair of second refrigerant supply ports 42a provided on the side surface 32b of the main body 32.

[0027] The specific examples of the technology disclosed in this specification have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes to the specific examples described above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives itself constitutes technical usefulness. [Explanation of Symbols]

[0028] 2, 4, 6: Drive Unit 8: Casing 10: Motor 11: Rotor 12: Shaft 13: Rotor Core 14: Magnet 15: Status 16: Stator Core 18: Coil 18a: Coil end 20: Power line 20a: Terminal section 30:Terminal block 32: Main body 32a: Lower part 32b: Side 34: Side wall section 40: First refrigerant supply channel 40a: First refrigerant supply port 42: Second refrigerant supply channel 42b: Second refrigerant supply port 50: Refrigerant

Claims

1. A motor having coils wound around a stator core, Multiple power lines extending from the coil, each having a terminal at its end, A terminal block for holding the terminal portions of the plurality of power lines, A refrigerant supply port that injects refrigerant toward the coil end, which is a part of the coil and protrudes from the end face of the stator core, Equipped with, The terminal block comprises a main body positioned opposite the coil end and a pair of side wall portions extending from the main body toward the coil end. The refrigerant supply port, in the space enclosed by the main body and the pair of side walls of the terminal block, injects the refrigerant toward the coil end. Drive unit.

2. The main body of the terminal block is located above the rotating shaft of the motor. The drive unit according to claim 1, wherein the pair of side walls of the terminal block each extend downward from the main body.

3. The drive unit according to claim 1, wherein the refrigerant supply port is provided on the main body of the terminal block.

4. The main body of the terminal block is A first refrigerant supply channel for supplying the refrigerant to the refrigerant supply port, The drive unit according to claim 3, further comprising at least one second refrigerant supply channel branching off from the first refrigerant supply channel and extending within the main body.

5. The drive unit according to claim 4, wherein the at least one second refrigerant supply channel extends along the direction of arrangement of the terminal portions of the plurality of power lines.

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