Electrical system

Abstract

The present application aims to improve the cooling performance of a bus bar with a simple system. The electric motor system of the present application comprises: a motor section having a stator and a rotor, cooled by a refrigerant; an inverter section supplying power to the winding of the stator; a line section transmitting power output from the inverter section to the motor section; and a pipe supplying or discharging the refrigerant to the motor section, the line section being arranged at a position capable of exchanging heat with an oily medium cooled by the pipe.

Description

TECHNICAL FIELD

[0001] The present application relates to an electric system of a vehicle drive device. BACKGROUND

[0002] In recent years, motors are practically used as a drive device for a vehicle. The motor as a drive device for a vehicle is driven by an inverter, and drives a vehicle through a gear provided at the output shaft end of the motor. The gear has a function of reducing the rotational speed of the motor and transmitting the motor torque to the axle. In such an electric system, the lubricating oil of the gear is used for the coil cooling of the motor to improve the cooling performance of the coil, and the motor is downsized and high torque is sought.

[0003] As background art in this technical field, there is Patent Literature 1 (Japanese Patent Laid-Open No. 2012-105457). Patent Literature 1 discloses a motor including a rotor configured to be rotatable around a rotational shaft, a stator provided around the rotor, a cooling circuit provided on an oil storage member that stores oil, which circulates cooling water to cool the oil of the oil storage member, and a speed reducer having an external gear that converts the rotational speed of the rotor and stirs the oil of the oil storage member (see claim 1).

[0004] Prior Art Documents

[0005] Patent Literature

[0006] Patent Literature 1: Japanese Patent Laid-Open No. 2012-105457 SUMMARY

[0007] Problems to be Solved by the Invention

[0008] In such an electric system, the line (for example, bus bar) connecting the motor and the inverter generates heat, and the bus bar needs to be cooled. If the lubricating oil is used for the cooling of the bus bar, the temperature of the lubricating oil rises, so the lubricating oil also needs to be cooled. On the other hand, the provision of an oil cooler for cooling the lubricating oil generally increases the cost.

[0009] Therefore, the industry is seeking to improve the cooling performance of the bus bar with a simple system.

[0010] Technical Means for Solving the Problem

[0011] A representative example of the application disclosed in this application is shown below. That is, an electric system including a motor portion having a stator and a rotor cooled by a refrigerant, an inverter portion that supplies power to the winding of the stator, a line portion that transmits power output from the inverter portion to the motor portion, and a pipe that supplies or discharges the refrigerant to the motor portion, the pipe being provided at a position capable of exchanging heat with an oil medium cooled by the pipe.

[0012] Effects of Invention

[0013] According to the present application, the gear lubricant oil can be used to cool the busbar, and the cooling performance of the motor can be improved.

[0014] The problems, configurations, and effects other than those described above will be clarified by the following examples. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a lateral cross-sectional view of the electric system of Example 1 of the present application.

[0016] Figure 2 is a cross-sectional perspective view of the motor and inverter portion of Example 1 of the present application.

[0017] Figure 3 is a cross-sectional perspective view of the motor and inverter portion of Example 1 of the present application.

[0018] Figure 4 is a front view of the electric system of Example 1 of the present application, viewed from the axial direction.

[0019] Figure 5 is a cross-sectional perspective view of the motor and inverter portion of Example 2 of the present application.

[0020] Figure 6 is a cross-sectional perspective view of the motor and inverter portion of Example 3 of the present application.

[0021] Figure 7 is a cross-sectional perspective view of the motor and inverter portion of Example 4 of the present application.

[0022] Figure 8 is a cross-sectional perspective view of the liquid storage portion of Example 4 of the present application, viewed from below.

[0023] Figure 9 is a cross-sectional perspective view of the motor and inverter portion of Example 5 of the present application.

[0024] Figure 10 is a cross-sectional perspective view of the motor and inverter portion of Example 6 of the present application. DETAILED DESCRIPTION

[0025] 〈Example 1〉

[0026] Figure 1 is a lateral cross-sectional view of the electric system of Example 1 of the present application. Figure 2 and Figure 3 is a cross-sectional perspective view of the motor and inverter portion of the electric system of Example 1 of the present application, Figure 3 shows a state in which the rotor and the gear are removed from Figure 2 Figure 4 ​A front view of the electric power system of Example 1 is shown from an axial direction.

[0027] The electric power system of this example is composed of a motor 1, an inverter 2 disposed adjacent to the motor 1, and a gear assembly 3 disposed in the output direction of the motor 1. The motor 1 is provided with a rotor 11 on the inner peripheral side of a stator 10, and a winding 12 is installed by being wound on the stator core. The type of the motor 1 is not limited, and can be a permanent magnet motor having a permanent magnet, a synchronous motor having a field winding, an induction motor having a cage conductor, a reluctance motor formed only of a rotor core, or the like, and the constituent parts for generating a magnetic field from the rotor and the shape thereof are not limited. The winding 12 is composed of a distributed winding or a concentrated winding, and can be composed of a rectangular wire or a round wire, and the winding method and the type are not limited. In the motor 1, a power source (for example, three-phase alternating current) is supplied to the motor 1 via a terminal pair of a bus bar 19.

[0028] The stator 10 is fixed to the inner peripheral side of a frame 16 by shrinkage fitting or bolted connection, or the like. The frame 16 is formed by low-pressure casting or die casting, or the like, and includes an end frame that supports a bearing, and the shape and the size thereof are not limited. The frame 16 is provided with a cooling water flow path 16A, and the cooling water flow path 16A is connected to an upper pipe 18A and a lower pipe 18B. That is, cooling water flows in from the upper pipe 18A, cools the motor 1 while passing through the cooling water flow path 16A, and is discharged from the lower pipe 18B. In addition, the cooling water flow path 16A is desirably communicated to the housing of the inverter 2, and the inverter 2 is also cooled by the cooling water. The inverter 2 can also be cooled via the frame 16 of the motor 1. The refrigerant circulating in the upper pipe 18A, the cooling water flow path 16A, and the lower pipe 18B can be water, or another kind of liquid such as oil.

[0029] The switching element of the inverter 2 can be an IGBT or SiC, or the like, and the type and the shape thereof are not limited. The motor input terminal led out from the winding 12 is connected to the inverter output terminal via the bus bar 19, and by applying a current and a voltage from the inverter 2, a current flows in the winding 12 and a rotating magnetic field is generated, so that the rotor 11 rotates to generate a torque. The rotor 11 is connected to the gear assembly 3 via a rotation shaft 17, and a gear output shaft 23 inside the gear assembly 3 is connected to an axle, so that the vehicle is driven. As shown in FIG. 1, the rotation shaft 17 can be a hollow rotation shaft or a solid rotation shaft, and the shape and the size thereof are not limited. Figure 2

[0030] The gear assembly 3 is provided with a plurality of gears 22A to 22D inside a gear case 21, and the gear ratio of the gears 22A to 22D is configured in such a manner that the rotation of the motor 1 is reduced by the gears 22A to 22D and is output from the gear output shaft 23. The gear assembly 3 is not limited to the configuration shown in FIG. 1, and the number of the gears, the shape and the size of the gears, and the like are not limited. Figure 1 ​In the example shown, the gear is composed of a spur gear with a parallel shaft, but the gear can also be a single planetary gear or a combination of planetary gears and spur gears. The configuration (parallel shaft or single shaft) and gear ratio are not limited. Furthermore, although not shown in the figure, a differential is typically installed between gear assembly 3 and the axle.

[0031] like Figure 1 As shown in gray, an oily medium accumulates in the lower part of the gear assembly 3. Gear 22B is immersed in the oily medium, and its rotation lubricates the space between gear 22B and gear 22A. Furthermore, as gears 22B and 22A rotate, the oily medium is thrown upwards and splashes onto the upper pipe 18A. The oily medium exchanges heat with cooling water at the top of the motor, and the cooling water in the upper pipe 18A cools the oily medium.

[0032] In addition, such as Figures 2 to 4 As shown, busbar 19 is located directly below the upper pipeline 18A, and the oily medium thrown upwards by gears 22B and 22A is like... Figure 3 , Figure 4 As shown by the dashed line, the oily medium drips from the upper pipe 18A onto the busbar 19, cooling the busbar 19. Furthermore, the lower pipe 18B is located directly below the busbar 19, and the oily medium drips from the busbar 19 onto the upper pipe 18A, cooling the oily medium using the cooling water in the lower pipe 18B.

[0033] Alternatively, an oily medium can be introduced into the frame 16, immersing the lower pipe 18B in the oily medium accumulated in the lower part of the frame 16, and then cooled by the cooling water flowing in the lower pipe 18B.

[0034] In this embodiment, the oily medium thrown upwards by the gears 22B and 22A can be cooled by the cooling water flowing in the upper pipe 18A, and the busbar 19 can be cooled by the oily medium dripping from the upper pipe 18A. Therefore, the cooling capacity of the motor 1 and the inverter 2 can be improved without adding water pipes, and the cooling water pipes used to cool the motor 1 and the inverter 2 can be simplified.

[0035] <Example 2>

[0036] Next, the electric system of Embodiment 2 will be described. The electric system of Embodiment 2 is provided with a fin 30 protruding from the cooling water pipes 18A and 18B. Furthermore, in Embodiment 2, the description of configurations having the same function as those in the embodiments described above will be omitted, and the different configurations will be mainly described.

[0037] Figure 5 This is a cross-sectional perspective view of the motor and inverter components of the electric system in Example 2.

[0038] A projection, i.e., a tab 30, is provided which projects from the outer surface of the upper pipe 18A to which the oil-based medium is applied. The projection can be a plate-shaped tab 30 as shown in the drawing, or can be a pin-shaped projection from the outer surface of the upper pipe 18A. The tab 30 is provided directly above the bus bar 19 in such a manner that the oil-based medium drips from the tab 30 to the bus bar 19 as shown by the broken line. Further, the projection can be a tab which is flat in the direction of extension of the upper pipe 18A as shown in the drawing, or can be helical in shape on the outer surface of the upper pipe 18A, and the shape is various. Further, the tab 30 desirably extends at least vertically downward of the upper pipe 18A.

[0039] As shown in the drawing, the tab 30 can be provided on both the upper pipe 18A and the lower pipe 18B, or can be provided on either one. Desirably, the tab 30 is provided at least on the upper pipe 18A.

[0040] In the present embodiment, the surface area of the cooling water pipes 18A, 18B is increased, and the cooling ability of the cooling water for the oil-based medium is improved.

[0041] [Embodiment 3]

[0042] Next, the electric system of Embodiment 3 will be described. In the electric system of Embodiment 3, the cooling water pipes 18A, 18B are bent at the positions where the oil-based medium is applied. Further, in Embodiment 3, the description of the configuration having the same function as that of the above-described embodiments is omitted, and the different configuration will be mainly described.

[0043] Figure 6 A cross-sectional perspective view of the motor and inverter section of the electric system of Embodiment 3.

[0044] In Embodiment 3, the upper pipe 18A is bent downward at the position where the oil-based medium is applied, and a U shape is formed. The lowermost portion of the upper pipe 18A desirably is provided directly above the bus bar 19 in such a manner that the oil-based medium drips from the upper pipe 18A to the bus bar 19. The bent portion of the upper pipe 18A can extend vertically, or can extend obliquely downward.

[0045] Further, the lower pipe 18B is bent upward at the position where the oil-based medium is applied, and a U shape is formed. The bent portion of the lower pipe 18B desirably is provided directly below the bus bar 19 in such a manner that the oil-based medium applied to the bus bar 19 contacts the bent portion of the lower pipe 18B.

[0046] As shown in the drawing, the bent portion can be provided on both the upper pipe 18A and the lower pipe 18B, or can be provided on either one. Desirably, the bent portion is provided at least on the upper pipe 18A.

[0047] In the present embodiment, the area of the oil medium in contact with the cooling water pipes 18A, 18B is increased, and the cooling ability of the cooling water for the oil medium can be improved.

[0048] <Embodiment 4>

[0049] Next, the electric power system of Embodiment 4 will be described. The electric power system of Embodiment 4 is provided with a liquid reservoir 31 below the upper pipe 18A. Further, in Embodiment 4, the description of the configuration having the same function as that of the above-described embodiments will be omitted, and the different configuration will be mainly described.

[0050] Figure 7 FIG. 13 is a cross-sectional perspective view of the motor and inverter section of the electric power system of Embodiment 4, Figure 8 FIG. 14 is a cross-sectional perspective view of the liquid reservoir of Embodiment 4 as viewed from below.

[0051] In Embodiment 4, the liquid reservoir 31 is provided below the upper pipe 18A. The liquid reservoir 31 has, for example, a bottom surface and a side wall of a prescribed height, and retains the oil medium thrown up by the gears 22B, 22A to a prescribed amount until the liquid level of the retained oil medium exceeds the height of the side wall and overflows. It is desirable to provide a discharge portion that becomes the outlet of the overflowing oil medium above the bus bar 19 in a manner that the oil medium overflowing from the liquid reservoir 31 drips onto the bus bar 19. The oil medium retained in the liquid reservoir 31 impregnates at least a portion of the upper pipe 18A and is cooled by the cooling water flowing in the upper pipe 18A.

[0052] Further, the discharge portion can be provided on the bottom surface of the liquid reservoir 31. For example, it is desirable to provide a discharge hole 31A above the bus bar 19 on the bottom surface of the liquid reservoir 31 in a manner that the oil medium drips onto the bus bar 19 from the liquid reservoir 31 (indicated by a dotted line). Figure 8

[0053] In the present embodiment, the oil medium is cooled in the liquid reservoir 31, and thus the cooling ability of the oil medium can be improved, and the bus bar 19 can be efficiently cooled. Further, the discharge portion (for example, the outlet of the oil medium, the discharge hole 31A) causes the oil medium to accurately drip onto the bus bar 19, and the temperature of the bus bar 19 can be reduced.

[0054] <Embodiment 5>

[0055] Next, the electric power system of Embodiment 5 will be described. The electric power system of Embodiment 5 is provided with a liquid reservoir 31 below the upper pipe 18A. Further, in Embodiment 5, the description of the configuration having the same function as that of the above-described embodiments will be omitted, and the different configuration will be mainly described.

[0056] Figure 9 ​This is a cross-sectional perspective view of the motor and inverter components of the electric system in Example 5.

[0057] In Embodiment 5, the cooling water inlet 18D of the upper pipe 18A is positioned higher in the vertical direction than the outlet 18E. That is, the upper pipe 18A has an inclined section whose vertical height gradually decreases the further away from the inlet 18D. Furthermore, the upper pipe 18A is positioned directly above the busbar 19 at the bend 18F connecting the outlet 18E and the inclined section. Oily media contacting the upper pipe 18A flow down from the inlet 18D along the lower surface of the inclined section of the upper pipe 18A, dripping from the bend 18F onto the busbar 19 as illustrated by the dashed line.

[0058] In this embodiment, the position where the oily medium accurately drips onto the busbar 19 is determined by the bend 18F, which can improve the cooling efficiency of the busbar 19.

[0059] <Example 6>

[0060] Next, the electric system of Example 6 will be described. The electric system of Example 6 is provided with axial oil passages 32 and 33 for flowing an oily medium to the side opposite to the gear. Furthermore, in Example 6, the description of configurations having the same function as the embodiments described above will be omitted, and the different configurations will be mainly described.

[0061] Figure 10 This is a cross-sectional perspective view of the motor and inverter components of the electric system in Example 6.

[0062] The motor 1 achieves cooling performance by allowing an oily medium to flow through or immerse the coil end of the winding 12, which protrudes from the end face of the stator core. This coil end also exists on the side away from the gear assembly 3. In the electric system of this embodiment, by providing an oil passage 32 leading from the gear assembly 3 to the side of the motor 1 away from the gear assembly 3, the oily medium thrown upwards by gears 22A and 22B inside the gearbox 21 can flow to the coil end of the motor 1 on the side away from the gear assembly 3, thereby improving the cooling performance of the winding 12. Furthermore, the oily medium can be fully utilized for cooling the bearings on the side away from the gear assembly 3.

[0063] Furthermore, by providing an oil passage 33 from the side of the motor 1 away from the gear assembly 3 to the gear assembly 3, the oily medium can be sent back from the side of the motor 1 away from the gear assembly 3 to the gear assembly 3, so that the oily medium can circulate throughout the electric system.

[0064] Furthermore, Figure 10 In the middle, oil circuits 32 and 33 are located between motor 1 and inverter 2, but are not limited to... Figure 10The position shown can also be provided on the top side (upper side) of the top and bottom of the motor 1 or on the side of the motor 1 opposite the inverter 2, etc. Further, Figure 10 The cross-sectional view of the position of the oil passages 32, 33 is shown in a manner that the oil passages 32, 33 are visible, but in fact, the oil passages are formed. Further, regarding the shape of the oil passages 32, 33, as long as the oil passages can be formed, it can also be a cylindrical shape, etc. rather than a rectangular shape as shown in the drawing. Figure 10 The shape shown is not particularly limited.

[0065] Further, the present application includes various modifications and equivalent configurations within the spirit of the appended claims and is not limited to the embodiments described above. For example, the embodiments described above are detailed descriptions made in order to explain the present application in an easy-to-understand manner, and the present application is not necessarily limited to all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Further, the configuration of one embodiment can be added with the configuration of another embodiment. Further, a part of the configuration of each embodiment can be added, deleted, or replaced with another configuration.

[0066] Symbol Explanation

[0067] 1... motor, 2... inverter, 3... gear assembly, 10... stator, 11... rotor, 12... winding, 16... frame, 16A... cooling water flow path, 17... rotation shaft, 18A... upper pipe, 18B... lower pipe, 18D... inlet portion, 18E... outlet portion, 18F... elbow portion, 19... bus bar, 21... gear box, 22A, 22B, 22C, 22D... gear, 23... gear output shaft, 30... tab, 31... liquid storage portion, 31A... discharge hole, 32, 33... axial oil passage.

Claims

1. An electric system, characterized in that, have: The motor section, which has a stator and a rotor, is cooled by a refrigerant; The inverter section supplies power to the windings of the stator; The gear section reduces the rotational speed of the rotor and is lubricated by an oily medium. The circuit section transmits the power output from the inverter section to the motor section; and Piping that supplies or discharges refrigerant to or from the motor unit. The circuit section is positioned to exchange heat with the oily medium after it has been cooled by the pipeline. The pipeline is positioned to exchange heat with the oily medium that is thrown upwards by the rotation of the gears in the gear section. The wiring section is located directly below the pipeline.

2. The electric system according to claim 1, characterized in that, The pipeline has a protrusion that extends from its outer surface. The wiring section is located directly below the protrusion.

3. The electric system according to claim 1, characterized in that, The pipeline has a downward-curving section. The circuit section is located directly below the bend.

4. The electric system according to claim 1, characterized in that, Below the pipeline is a reservoir for storing the oily medium.

5. The electric system according to claim 4, characterized in that, The liquid storage section has a discharge section that discharges the oily medium in a manner that contacts the circuit section.

6. The electric system according to claim 1, characterized in that, The inlet of the refrigerant flowing into the pipeline is located at a position higher than the outlet of the pipeline where the cooling flow path of the motor unit connects.

7. The electric system according to claim 6, characterized in that, The pipeline has an inclined section between the inlet and the outlet, where the vertical height increases as it approaches the inlet. The line section is located directly below the connection point between the outlet section and the inclined section.

8. The electric system according to claim 1, characterized in that, The pipeline has a first oil passage and a second oil passage at a position where they overlap in the vertical direction. The first oil passage allows the oily medium to flow from the output shaft side of the motor unit toward the side of the motor unit away from the output shaft. The second oil passage allows the oily medium to flow from the side of the motor unit away from the output shaft toward the output shaft side. The first oil passage is in contact with the pipeline, and the oily medium in the first oil passage is cooled by the refrigerant in the pipeline.

Images