Motor system

Abstract

The present application aims to provide a motor system capable of suppressing a decrease in cooling performance caused by mixing of bubbles (air) into refrigerant. The motor system (100) of the present application includes a gear (134), a first face (155) that receives oil that is lifted up as the gear (134) rotates, a second face (153) that is located below in the vertical direction with respect to the first face (155), is opposed to the first face (155) at a position overlapping the first face (155) in the vertical direction, receives oil that drips from the first face (155), and receives oil that is lifted up as the gear (134) rotates, and a recess (151) that is located below in the vertical direction with respect to the second face (153) and into which oil received by the second face (153) flows. Both ends of the second face (153) in a horizontal direction that is perpendicular to the vertical direction and perpendicular to the axis of the gear (134) are located inside both ends in the horizontal direction of the recess (151).

Description

Technical Field

[0001] The present invention relates to an electric motor system (e-Axle) used as a power source for electric vehicles, hybrid vehicles that use electric motors and internal combustion engines as power sources, and includes an electric motor, an inverter, and a speed reducer. Background Technology

[0002] As background technology in this field, a motor unit described in International Patent Publication No. 2018 / 030372 (Patent Document 1) is known. Patent Document 1 describes a motor unit comprising: a motor having a rotor; a reduction gear having an intermediate gear rotating about an intermediate shaft; a differential gear having a ring gear rotating about a differential shaft; a housing; oil accumulating in a region on the lower vertical side of a storage space; and an oil passage supplying oil to the motor, wherein at least a portion of the ring gear is located below the surface of the oil in the region on the lower vertical side of the storage space (see abstract).

[0003] In the motor unit of Patent Document 1, a housing space for accommodating the motor, reduction gear, and differential gear is provided inside the housing. An oil reservoir for accumulating oil is provided in the area below the housing space (see paragraphs 0017-0018). A portion of the differential gear is immersed in the oil reservoir, and the oil accumulated in the reservoir rises due to the operation of the differential gear, with a portion being supplied to the first oil passage (paragraph 0019). A reservoir for receiving the oil lifted by the differential gear is provided in the path of the first oil passage (paragraphs 0024, 0107). Furthermore, a plate-shaped eaves is disposed on the top of the gear chamber and extends axially (paragraph 0115). A portion of the oil dispersed by the ring gear of the differential gear contacts the eaves and flows along its surface. The oil forms larger droplets at the lower end of the eaves, falls downwards, and accumulates in the first reservoir (paragraph 0115). Existing technical documents Patent documents

[0004] Patent Document 1: International Publication No. 2018 / 030372 Summary of the Invention The problem the invention aims to solve

[0005] In the motor unit of Patent Document 1, the oil flowing along the surface of the eaves becomes a larger droplet at the lower end of the eaves and falls into the first reservoir. The oil collides with the surface of the oil accumulated in the first reservoir and generates bubbles. The bubbles may mix into the oil accumulated in the first reservoir.

[0006] Hereinafter, the refrigerant will not be limited to oil, but will be referred to as refrigerant. If air bubbles (air) are mixed into the refrigerant, heat transfer within the refrigerant or between the refrigerant and the equipment requiring cooling will be hindered, resulting in reduced cooling performance. Patent Document 1 did not take into account this reduction in cooling performance.

[0007] The purpose of this invention is to provide an electric motor system that can suppress the reduction in cooling performance caused by the mixing of air bubbles into the refrigerant. Technical means to solve the problem

[0008] To achieve the above objectives, the electric motor system of the present invention comprises: gear; The first surface receives the oil that is thrown up as the gear rotates; The second surface, located vertically below the first surface and overlapping it in the vertical direction, receives oil dripping from the first surface and also receives oil splashed up as the gear rotates; and A recess, which is located vertically below the second surface, allows oil received by the second surface to flow in. The two ends of the second surface, which are perpendicular to the vertical direction and perpendicular to the axis of the gear, are located inside the two ends of the recess in the horizontal direction.

[0009] In addition, to achieve the above objectives, the electric motor system of the present invention comprises: gear; The first surface receives the oil that is thrown up as the gear rotates; The second surface, located vertically below the first surface and overlapping it in the vertical direction, receives oil dripping from the first surface and also receives oil splashed up as the gear rotates; and A recess, located vertically below the second surface, allows oil collected by the second surface to flow in. The first surface is inclined in a horizontal direction perpendicular to the vertical direction and the axis of the gear, such that the side closer to the gear is located above the vertical direction and the side farther from the gear is located below the vertical direction. The second surface is inclined in the horizontal direction with its end closer to the gear positioned above the vertical direction relative to its end farther from the gear. A flow path communicating with the inside of the recess is formed on one side of the end away from the gear. The effects of the invention

[0010] According to the present invention, an electric motor system capable of suppressing the reduction in cooling performance caused by the mixing of air bubbles into the refrigerant can be provided.

[0011] The following description of the implementation methods will clarify the issues, structures, and effects other than those described above. Attached Figure Description

[0012] Figure 1 This is a plan view showing the configuration of the storage section (gear storage space) of the speed reduction device and differential device of the electric motor system according to an embodiment of the present invention. Figure 2 It means Figure 1 A cross-sectional view of the motor system at section II-II. Figure 3 It is about Figure 1 The diagram shows a perspective view of the motor system, taken from an oblique angle, of the storage area (gear storage space) for the reduction gear and differential gear. Figure 4 This is a plan view of the refrigerant relay section of an electric motor system applied in an embodiment of the present invention, viewed from the axial direction of the electric motor. Figure 5 This diagram shows a modified example of the refrigerant relay section, and is a plan view of the refrigerant relay section viewed from the axial direction of the motor. Figure 6 This diagram shows a modified example of the refrigerant relay section, and is a plan view of the refrigerant relay section viewed from the axial direction of the motor. Detailed Implementation

[0013] Hereinafter, an embodiment of the electric motor system (electric drive device) of the present invention will be described with reference to the accompanying drawings. The electric motor system of this embodiment, as an e-Axle including an electric motor, an inverter, and a reduction gear (reducer), is used as a drive unit for automobiles such as electric vehicles and hybrid vehicles that use an electric motor as at least part of the drive source.

[0014] Figure 1 This is a plan view showing the configuration of the gear reduction device 120 and the differential device 130 housing (gear housing space) 102 of the electric motor system 100 according to an embodiment of the present invention.

[0015] according to Figure 1 Define the up / down and left / right directions. The up / down direction is the vertical direction, and the left / right direction is the same as the horizontal direction. The up / down and left / right directions do not need to be aligned with... Figure 1 The directions shown are completely consistent, or relative to... Figure 1 The direction shown is slightly tilted. Furthermore, the direction along the axis of the output shaft 110a of the motor 110 will be referred to as the axial direction.

[0016] The electric motor system 100 includes an electric motor 110 (see reference). Figure 2 ), reduction gear 120 and differential gear 130, motor 110 (see reference) Figure 2 The reduction gear 120 and the differential gear 130 are housed inside the gear chamber (gear housing) 102 of the housing 140.

[0017] exist Figure 1 In the diagram, the dashed line RL represents the liquid level of the refrigerant Re sealed within the housing 140. That is, the motor system 100 operates with the refrigerant reservoir Re sealed within the housing 140 at a liquid level of RL. The refrigerant is typically an oil that also serves as a lubricant. The motor system 100 has a refrigerant flow path that circulates the refrigerant from the refrigerant reservoir Re to the motor 110 side. Although there are cases where the refrigerant flow path is configured to pass through the outside of the housing 140, the term "sealed" is used to ensure that the refrigerant does not leak to the outside of the housing 140. This refrigerant flow path will be described in detail later.

[0018] Reference Figure 1 and Figure 2 Please provide an explanation. Figure 2 It means Figure 1 A cross-sectional view of the motor system at section II-II.

[0019] like Figure 2 As shown, in the motor system 100, the gear chamber 102 is separated from the motor 110 side by a partition wall 142, and the reduction gear 120 and differential gear 130 are disposed in the gear chamber 102. In this embodiment, the housing 140 is composed of two housing members 140A and 140B, with the gear chamber 102 located on the first housing member 140A side. The motor 110 is disposed on the second housing member 140B side. The housing member 140 may not need to be composed of two members, may be composed of one member, or may be composed of three or more members. Furthermore, the partition wall 142 is integrally formed with the first housing member 140A.

[0020] like Figure 1As shown, the reducer 120 comprises a first gear 121, a second gear 122, and a third gear 123. The first gear 121 is mounted on the rotating output shaft 112 of the output motor 110 and rotates integrally with the output shaft 112. That is, the shaft of the first gear 121 is formed by the output shaft 112. The second gear 122 and the third gear 123 are mounted on a shaft 124, and the second gear 122, the third gear 123, and the shaft 124 rotate integrally around the axis of the shaft 124. The diameter of the second gear 122 is larger than that of the third gear 123, meshes with the first gear 121, and is driven by the first gear 121. The diameter of the third gear 123 is smaller than that of the second gear 122, is disposed on the side of the partition wall 142 relative to the second gear 122, and meshes with the fourth gear 134 constituting the differential device 130 to drive the fourth gear 134.

[0021] As explained above, the rotation of the motor 110 is transmitted to the fourth gear 134, which constitutes the differential device 130, via the first gear 121, the second gear 122, and the third gear 123 constituting the reduction gear 120. At this time, according to the reduction ratio of the first gear 121, the second gear 122, and the third gear 123, the rotational speed decreases and the torque increases. Furthermore, the configuration of the reduction gear 120 is not limited to the above-described configuration; for example, the number and arrangement of the gears can be different.

[0022] The differential device 130 is a device that transmits the rotational output of the electric motor 110 to the wheels, and has a fourth gear 134 driven by the reduction gear 120. The fourth gear 134 is mounted on the differential shaft 132 and rotates around the axis of the differential shaft 132. In this embodiment, the fourth gear 134 is composed of a ring gear.

[0023] The electric motor 110 has an output shaft 112, a stator core 114, a rotor core 116, and coils 118. The output shaft 112 and the rotor core 116 constitute the rotor. The stator core 114 and the coils 118 constitute the stator. The output shaft 112 may be composed of a single component or multiple components. The output shaft 112 has a hollow portion 112a extending axially at its radial center.

[0024] The output shaft 112 of the motor 110, the shaft 124 of the second gear 122 and the third gear 123, and the differential shaft 132 of the differential device 130 are arranged in parallel.

[0025] Next, refer to Figure 1 and Figure 3 and Figure 4 The refrigerant relay section 150 will be explained. Figure 3 It is about Figure 1The figure shows a perspective view of the storage section (gear storage space) 102 of the motor system 100, which is viewed from an oblique angle, for the reduction gear 120 and the differential gear 130. Figure 4 This is a plan view of the refrigerant relay section 150 of an electric motor system applied in an embodiment of the present invention, viewed from the axial direction of the electric motor 110.

[0026] like Figure 1 As shown, the fourth gear 134 of the differential device 130 is configured such that a portion of it is immersed in the refrigerant storage section Re. The refrigerant in the refrigerant storage section Re is propelled by the rotation of the fourth gear 134, as indicated by arrows F1 and F2, and is received by the refrigerant relay section (oil relay section) 150. The refrigerant relay section 150 is located midway in the refrigerant flow path from the refrigerant storage section Re to the motor 110, constituting a refrigerant storage section for storing refrigerant. When the refrigerant storage section Re is used as the first refrigerant storage section, the refrigerant relay section 150 becomes the second refrigerant storage section.

[0027] like Figure 3 As shown, the refrigerant F6 stored in the refrigerant relay section 150 flows to the motor 110 side through the hollow section 112a of the output shaft 112 of the motor 110.

[0028] like Figure 3 and Figure 4 As shown, the refrigerant relay section 150 has a first surface 155, a second surface 153, and a recess 151.

[0029] The first surface 155 is formed by the surface of the component (part) constituting the first surface 155 facing the fourth gear 134. The first surface 155 is inclined in such a way that, in a horizontal direction (left-right direction) perpendicular to the vertical direction and perpendicular to the axis of the fourth gear 134, the side closer to the fourth gear 134 is located above the vertical direction, and the side farther away from the fourth gear 134 is located below the vertical direction.

[0030] The first face 155 is lifted up as the fourth gear 134 rotates, receiving as... Figure 1 Arrow F1 indicates the refrigerant (oil) being ejected. The first surface 155 forms a guide surface (guide section) that guides the received refrigerant F3 to the second surface 153.

[0031] The second surface 153 is formed by the upper surface of the component (part) constituting the second surface 153. The second surface 153 is located vertically below the first surface 155, and is opposite to the first surface 155 at a position where it overlaps with the first surface 155 in the vertical direction. Thus, it receives refrigerant F4 dripping from the first surface 155. Furthermore, the second surface 153 is lifted up as the fourth gear 134 rotates, receiving refrigerant F4 dripping from the first surface 155. Figure 1 Arrow F2 indicates the refrigerant (oil) being ejected.

[0032] Here, the second surface 153 is opposite to the first surface 155 in the vertical direction at a position where it overlaps with the first surface 155, and in the left-right direction, it is opposite to the first surface 155 in a position (range) where it overlaps with the first surface 155. In addition, the second surface 153 is arranged apart from the lower end of the first surface 155.

[0033] The second surface 153 is configured to cover a portion of the opening of the recess 151. Specifically, the left and right ends 153L and 153R of the second surface 153 are located inside the left and right ends 151L and 151R of the recess 151. More specifically, the left end 153L of the second surface 153 is located at a distance WL inward relative to the left end 151L of the recess 151, and the right end 153R of the second surface 153 is located at a distance WR inward relative to the right end 151R of the recess 151. In this case, the WL of the recess 151 is greater than the WR.

[0034] The second surface 153 forms a cover member in the left-right direction that covers the central portion of the opening of the recess 151. The two ends 153L and 153R of the second surface 153 in the left-right direction are located below the two ends 151L and 151R of the recess 151 in the left-right direction in the vertical direction. Furthermore, flow paths SL and SR are formed on the two ends 153L and 153R of the second surface 153 in the left-right direction, communicating with the inner side of the recess 151 (refrigerant storage section 151a). Therefore, the refrigerant F5L and F5R received by the second surface 153 can be reliably guided to the refrigerant storage section 151a inside the recess 151. exist Figure 4 In this case, the width of the flow path SR in the left and right directions is made larger than the width of the flow path SL. However, by making the width of the flow path SR smaller than the width of the flow path SL, the amount of refrigerant F2 that flies directly into the refrigerant storage section 151a of the recess 151 without colliding with the first surface 155 can be reduced.

[0035] Furthermore, in this embodiment, the second surface 153 is constructed as a curved surface that protrudes vertically upwards from the portion between the two ends 153L and 153R in the left-right direction. This shortens the distance between the lower ends of the second surface 153 and the first surface 155, suppressing air entrapment of refrigerant dripping from the first surface 155 onto the second surface 153. Additionally, by constructing the second surface 153 as an inclined surface descending towards the two ends 153L and 153R, the refrigerants F5L and F5R can be smoothly guided to the flow paths SL and SR, suppressing excessive retention of refrigerants F5L and F5R on the second surface 153.

[0036] The recess 151 is located vertically below the second surface 153, and refrigerant received by the second surface 153 flows into the recess 151. The recess 151 has the function of temporarily storing the flowing refrigerant and becomes the main part of the second refrigerant storage section.

[0037] In the direction of refrigerant F2 ejection, the upper end of the side wall 151b of the front recess 151 is positioned Ha higher than the left end 153L of the second surface 153, and the upper end of the side wall 151c on the opposite side of the recess 151 is positioned Hc higher than the right end 153R of the second surface 153. Furthermore, the upper end of the left side wall 151b is positioned Hb higher than the upper end of the right side wall 151c.

[0038] The left end 151L of the recess 151 is located at a distance WL from the left end 153L of the second surface 153, and the right end 151R of the recess 151 is located at a distance WR from the right end 153R of the second surface 153. In this case, the left sidewall 151b of the recess 151 forms a large inclined surface, and its upper end is located at a position Hb higher than the upper end of the right sidewall 151c. Therefore, the WL of the recess 151 is greater than the WR.

[0039] Without the second surface 153, the distance h0 between the lower end of the first surface 155 and the liquid surface of the refrigerant storage section 151a increases, resulting in a greater falling velocity of the refrigerant F4 dripping from the lower end of the first surface 155 onto the liquid surface of the refrigerant storage section 151a. This increased falling velocity of the refrigerant F4 entrains air as it drips onto the liquid surface of the refrigerant storage section 151a, introducing air bubbles into the refrigerant. Furthermore, the refrigerant F2, by colliding with the liquid surface of the refrigerant storage section 151a at a higher jet velocity, also entrains air, introducing air bubbles into the refrigerant. Because of these air bubbles, the refrigerant's cooling performance is reduced, as they impede heat transfer.

[0040] In this embodiment, by providing a second surface 153 and receiving refrigerant F4 dripping from the lower end of the first surface 155, the falling velocity of refrigerant F5L and F5R dripping onto the liquid surface of the refrigerant storage section 151a can be reduced. Furthermore, by receiving refrigerant F2 through the second surface 153, collisions with the liquid surface of the refrigerant storage section 151a at high jet speeds can be prevented. In this embodiment, by introducing refrigerant flows F3 and F4 via the first surface 155 and refrigerant flow F2 that does not pass through the first surface 155 into the refrigerant storage section 151a, the flow rate of refrigerant introduced into the refrigerant storage section 151a can be ensured, and air bubbles mixed into the refrigerant in the refrigerant storage section 151a can be reduced, thereby suppressing the decrease in the cooling performance of the refrigerant.

[0041] In addition, in this embodiment, the refrigerant flow rate is reduced during the movement of the second surface 153, and it remains on the second surface 153, which can reduce the number of bubbles generated in the refrigerant.

[0042] When the vehicle is reversing, the fourth gear 134 reverses, resulting in insufficient refrigerant supply from the fourth gear 134 to the refrigerant relay section 150. In this case, the refrigerant supply to the refrigerant relay section 150 can be increased by increasing the discharge rate of an oil pump (not shown).

[0043] Next, refer to Figure 5 Explain a modified example of the refrigerant relay section 150. Figure 5 The diagram shows a modified example of the refrigerant relay section 150, and is a plan view of the refrigerant relay section 150 viewed from the axial direction of the motor 110.

[0044] In this example, the left end 153L of the second surface 153 is positioned to overlap with the left sidewall 151b of the recess 151, which forms an inclined surface relative to the vertical direction, in the left-right direction, and the right end 153R of the second surface 153 is positioned to overlap with the right sidewall 151c of the recess 151, which forms an inclined surface relative to the vertical direction, in the left-right direction. That is, the recess 151 is formed by the inclined surfaces of the portions (sidewalls) 151b and 151c that receive oil flowing in from the second surface 153, which are inclined relative to the vertical direction.

[0045] Therefore, the refrigerant dripping from the second surface 153 flows down the inclined surfaces of the side walls 151b and 151c, thereby suppressing the generation of bubbles.

[0046] Other configurations can be made in the same manner as the above embodiments to achieve the same effects.

[0047] Next, refer to Figure 6 Explain a modified example of the refrigerant relay section 150. Figure 6 The diagram shows a modified example of the refrigerant relay section 150, and is a plan view of the refrigerant relay section 150 viewed from the axial direction of the motor 110.

[0048] In this example, the refrigerant relay section 150 differs from the embodiment described above in the configuration of its second surface 153. In this example, the second surface 153 is inclined such that its end 153R, located closer to the fourth gear 134 (right side), is positioned vertically above its end 153L, located further away from the fourth gear 134 (left side). That is, it is constructed as an inclined surface tilted in one direction. Furthermore, a flow path SL is formed on the side (left side) away from the fourth gear 134, communicating with the inside of the recess 151, through which the refrigerant collected on the second surface 153 flows into the recess 151.

[0049] In this example, the flow path communicating with the inside of the recess 151 is only the left SL, and the right SR is not provided. Therefore, it is possible to reduce the amount of refrigerant that flies directly into the inside of the recess 151 without passing through the second surface 153, and to suppress air (bubbles) from mixing into the refrigerant in the refrigerant storage section 151a.

[0050] Other configurations can be made in the same manner as the above embodiments to achieve the same effects.

[0051] Furthermore, the present invention is not limited to the embodiments described above, but includes various modifications. For example, the embodiments described above are detailed examples for the purpose of readily understanding the present invention and are not necessarily limited to embodiments having all the necessary configurations. Additionally, for a portion of the configuration of each embodiment, other configurations may be added, deleted, or replaced. Symbol Explanation

[0052] 134… Fourth gear, 150… Refrigerant relay section, 151… Recess, 151b, 151c… Recess 151 portion (sidewall) for receiving oil flowing in from the second surface 153, 151L, 151R… Both ends of the recess 151 in the left-right direction, 153… Second surface, 153L, 153R… Both ends of the second surface 153 in the left-right direction, 155… First surface, F1~F5L, F5R… Refrigerant (oil), SL… Flow path formed on the side (left side) of the end 153L away from the fourth gear 134.

Claims

1. An electric motor system characterized by, have: gear; The first surface receives the oil that is thrown up as the gear rotates; The second surface is located vertically below the first surface, and is opposite to the first surface at a position where it overlaps with the first surface in the vertical direction. It receives oil dripping from the first surface and also receives oil that is stirred up as the gear rotates. as well as A recess, which is located vertically below the second surface, allows oil received by the second surface to flow in. The two ends of the second surface, which are perpendicular to the vertical direction and perpendicular to the axis of the gear, are located inside the two ends of the recess in the horizontal direction.

2. The electric motor system according to claim 1, characterized in that, The second surface is formed by a curved surface that protrudes vertically upwards from the two ends in the horizontal direction relative to the two ends in the horizontal direction.

3. The electric motor system according to claim 2, characterized in that, The two ends of the second surface in the horizontal direction are located below the two ends of the recess in the horizontal direction in the vertical direction.

4. The electric motor system according to claim 3, characterized in that, At both ends of the second surface in the horizontal direction, flow paths are formed that communicate with the inner side of the recess.

5. The electric motor system according to claim 4, characterized in that, The recess is formed by an inclined surface that receives oil flowing in from the second surface and is inclined relative to the vertical direction.

6. The electric motor system according to claim 1, characterized in that, The first surface is inclined such that the side closer to the gear in the horizontal direction is located above the vertical direction, and the side farther from the gear is located below the vertical direction.

7. An electric motor system characterized by, have: gear; The first surface receives the oil that is thrown up as the gear rotates; The second surface is located vertically below the first surface, and is opposite to the first surface at a position where it overlaps with the first surface in the vertical direction. It receives oil dripping from the first surface and also receives oil that is stirred up as the gear rotates. as well as A recess, located vertically below the second surface, allows oil collected by the second surface to flow in. The first surface is inclined such that, in a horizontal direction perpendicular to both the vertical direction and the axis of the gear, the side closer to the gear is located above the vertical direction, and the side farther from the gear is located below the vertical direction. The second surface is inclined such that the end on the side closer to the gear in the horizontal direction is positioned above the end on the side farther from the gear in the vertical direction. A flow path communicating with the inside of the recess is formed on one side of the end furthest from the gear.

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