transaxle

Abstract

To obtain a transaxle that can simplify the structure of an oil passage.SOLUTION: An oil pump 60 comprises a pump operation part for oil pumping connected to one end side of an input shaft 12 in an axial direction, and comprises a pump cover 64 forming a cover. The pump cover 64 is provided with a relief valve 70. The relief valve 70 is arranged on an upper side of the input shaft 12, and on the side of the input shaft 12 out of a lateral side of an MG1 shaft 26. The relief valve 70 is constituted so as to be capable of discharging oil toward the input shaft 12 and the MG1 shaft 26.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent Document 1 below discloses a technology related to a transaxle equipped with an oil passage for oil delivered from an oil pump. This prior art includes a pump cover that serves as a cover for the oil pump and forms part of the oil passage, and a relief valve attached to the pump cover that releases oil from the oil passage according to the pressure in the oil passage. This configuration eliminates the need to provide a separate member for forming an oil passage for relief inside the casing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-68430 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in this conventional technology, a separate oil passage is provided to supply oil to the gears and bearings in the gear chamber, and there is room for improvement in terms of simplifying the configuration of the oil passage.

[0005] In consideration of the above, an object of the present invention is to provide a transaxle that can simplify the configuration of oil passages. [Means for solving the problem]

[0006] The transaxle of the present invention described in claim 1 comprises an input shaft having a first gear portion to which engine output is transmitted, an electric motor shaft having a second gear portion that meshes with the first gear portion of the input shaft and is arranged above and to the side of the input shaft, an oil pump arranged in an oil passage for supplying oil to areas requiring lubrication or cooling and having a pump operating portion for pressurizing oil connected to one axial end of the input shaft, and having a pump cover that forms a cover and forms part of the oil passage, and a relief valve arranged on the pump cover and configured to discharge oil from the oil passage when the oil pressure in the oil passage exceeds a predetermined value, the relief valve being arranged above the input shaft and on the input shaft side of the lateral side of the electric motor shaft, and being capable of discharging oil toward the input shaft and the electric motor shaft.

[0007] According to the above configuration, engine output is transmitted to the first gear portion of the input shaft. The electric motor shaft, located above and to the side of the input shaft, has a second gear portion that meshes with the first gear portion of the input shaft. The oil pump includes a pump actuator and a pump cover. The pump actuator is connected to one axial end of the input shaft and serves to pump oil. The pump cover forms part of the oil passage. The relief valve on the pump cover is configured to discharge oil from the oil passage when the oil pressure in the oil passage exceeds a predetermined value. The relief valve is located above the input shaft and on the input shaft side of the electric motor shaft, and is capable of discharging oil toward the input shaft and the electric motor shaft. This eliminates the need for separate oil passages for supplying oil to the input shaft and the electric motor shaft.

[0008] The transaxle of the present invention described in claim 2 has the configuration described in claim 1, in which a parking member constituting a parking lock mechanism is arranged below the relief valve and on the opposite side of the electric motor shaft with respect to an imaginary line passing through the relief valve and the input shaft when viewed from the same direction as the axial direction of the input shaft, and the relief valve is configured to be able to discharge oil toward the parking member.

[0009] According to the above configuration, the parking member is disposed below the relief valve and on the opposite side of the electric motor shaft from the imaginary line passing through the relief valve and the input shaft when viewed from the same direction as the axial direction of the input shaft, and the relief valve is capable of discharging oil toward the parking member, which eliminates the need for a separate oil passage to supply oil to the parking member.

[0010] The transaxle of the present invention described in claim 3 is configured as described in claim 1 or claim 2, wherein the relief valve is disposed directly above the input shaft, and the distance from the relief valve to the electric motor shaft is set shorter than the distance from the relief valve to the input shaft.

[0011] According to the above configuration, the relief valve is located directly above the input shaft, so oil can be reliably supplied to the input shaft by letting the oil drop from the relief valve. On the other hand, oil cannot be supplied to the electric motor shaft simply by letting the oil drop from the relief valve, but the distance from the relief valve to the electric motor shaft is set shorter than the distance from the relief valve to the input shaft, so oil can be supplied to the electric motor shaft efficiently.

[0012] A transaxle of the present invention as set forth in claim 4 is the same as the configuration set forth in claim 1 or claim 2, in which the relief valve is disposed immediately to the side of the electric motor shaft.

[0013] According to the above configuration, oil can be supplied from the relief valve to the electric motor shaft from directly beside the electric motor shaft. [Effects of the Invention]

[0014] As described above, the transaxle of the present invention has the excellent effect of simplifying the configuration of the oil passages. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing a simplified transaxle according to an embodiment of the present invention with the engine-side case removed. [Figure 2] 2 is an enlarged cross-sectional view of the transaxle taken along a cutting line corresponding to line 2-2 in FIG. 1. [Figure 3] FIG. 2 is a simplified perspective view showing the motor compartment side of the transaxle. DETAILED DESCRIPTION OF THE INVENTION

[0016] A transaxle according to one embodiment of the present invention will be described with reference to FIGS.

[0017] (Configuration of the embodiment) FIG. 1 is a simplified perspective view of a transaxle 10 according to this embodiment with the engine-side case (not shown) removed. The transaxle 10 is mounted on a vehicle. The vehicle is provided with an engine (not shown) and a battery (not shown). The vehicle is a so-called series hybrid vehicle that can run by using the engine as a power source to drive a first electric motor 20, which in turn drives a second electric motor 30, and can also run by stopping the engine and using a battery as a power source to drive the second electric motor 30.

[0018] Note that the arrow UP in the figures indicates the upward side of the transaxle 10 when mounted on a vehicle. In the following description, the near side of the transaxle 10 when viewed from the engine side in the input direction from the engine (not shown) (the axial direction of the input shaft 12 described below) may be referred to as the "front Fr" and the far side as the "rear Rr." Furthermore, the arrow W shown in Figure 1 etc. indicates the width direction of the transaxle 10, which is the same direction as the axial direction of the input shaft 12 of the transaxle 10.

[0019] 1 includes a casing 40, a first electric motor (MG1) 20, a second electric motor (MG2) 30, and a differential mechanism (not shown). The transaxle 10 also includes an oil pump 60, a strainer 68, a relief valve 70, an oil cooler 80, and the like.

[0020] The casing 40 is, for example, a housing made up of three members arranged adjacently in the width direction W of the transaxle 10. FIG. 1 shows only one of the three members (the T / A case) that constitutes the middle portion of the casing 40 in the width direction W. To further explain, the front (Fr) side of the casing 40 is made up of a case (also referred to as a housing, not shown) having an opening at the middle portion of the casing 40 in the width direction W, and the rear (Rr) side is made up of a cover (not shown) having an opening at the middle portion of the casing 40 in the width direction W. The interior space of the casing 40 is partitioned by a partition wall 43 shown in FIG. 1 into a motor chamber 41 (see FIG. 3) on the rear (Rr) side and a gear chamber 42 on the front (Fr) side. The first electric motor 20 and the second electric motor 30 are housed in the motor chamber 41 (see FIG. 3). The input shaft 12, an MG1 shaft 26 (described later) serving as an electric motor shaft, and the like are disposed in the gear chamber 42.

[0021] An oil reservoir 44 is formed on the bottom side of the gear chamber 42 inside the casing 40. The oil reservoir 44 is a portion where oil circulating through an oil passage 100 (described later) is stored. A strainer 68 is disposed in the oil reservoir 44. The strainer 68 is configured to suck in the oil stored in the oil reservoir 44 when the oil pump 60 is operating and to filter the sucked oil.

[0022] Transaxle 10 is formed with an oil passage 100 for supplying oil to locations requiring lubrication or cooling. In FIG. 1, arrows A1, A2, and A3 indicate the flow of oil through oil passage 100 to oil cooler 80, while in FIG. 3, arrows A4, A5, and A6 indicate the flow of oil leaving oil cooler 80 and passing through oil passage 100 as viewed from the opposite side of FIG. 1. In other words, oil passage 100 in FIG. 1 is a passage through which oil flows as indicated by arrows A1, A2, and A3, while in FIG. 3, oil passage 100 is a passage through which oil flows as indicated by arrows A4, A5, and A6. Oil passage 100 includes a portion formed by multiple through-holes and recesses formed in casing 40 shown in FIG. 1 and other drawings, and a portion formed by components such as strainer 68. In transaxle 10, various components are lubricated or cooled by oil.

[0023] As shown in FIG. 3 , an upper oil passage 100A connected to the oil cooler 80 as part of the oil passage 100 extends above the first electric motor 20 and the second electric motor 30 in the direction in which the first electric motor 20 and the second electric motor 30 are aligned. A first pipe 101 connected to the upper oil passage 100A and protruding toward the rear Rr side is provided directly above the first electric motor 20, and a second pipe 102 connected to the upper oil passage 100A and protruding toward the rear Rr side is provided directly above the second electric motor 30. That is, the oil ejected from the first pipe 101 is configured to fall on the first electric motor 20, and the oil ejected from the second pipe 102 is configured to fall on the second electric motor 30. The positions of the oil ejection holes formed in the first pipe 101 and the second pipe 102 can be set as appropriate. In order to return the oil used for cooling the first electric motor 20 and the second electric motor 30, etc., to the oil reservoir 44 (see Figure 1), a passage (not shown) is formed between the motor chamber 41 and the gear chamber 42 shown in Figure 1.

[0024] The first electric motor 20 shown in Fig. 3 is made up of a motor generator. A generator controller incorporating an inverter and the like is connected to the first electric motor 20. AC power output from the first electric motor 20 is converted into DC power by the generator controller, and the DC power is supplied to a battery, thereby charging the battery. The first electric motor 20 is configured to be driven by rotational power transmitted by driving an engine (not shown).

[0025] The second electric motor 30 is made up of a motor generator. A motor controller incorporating an inverter and the like is connected to the second electric motor 30. A battery is connected to the motor controller. DC power output from the battery is supplied to the motor controller and converted into AC power by the motor controller. The AC power is then supplied to the second electric motor 30, thereby driving the second electric motor 30.

[0026] Figure 2 shows an enlarged cross-section of transaxle 10 taken along a cross-section line corresponding to line 2-2 in Figure 1. Note that in Figure 2, cross-sections of input shaft 12, MG1 shaft 26, bearings 16A, 16B, and 18 (described later), and a pump actuation section 62 (described later) are hatched, but cross-sections of other parts are not hatched for the sake of convenience.

[0027] The input shaft 12 shown in FIG. 2 is disposed along the vehicle width direction and rotatably supported by bearings 16A and 16B. The input shaft 12 is an element that can be understood as an engine shaft. A first gear portion 14 is formed on the outer periphery of the input shaft 12. The output of the engine is transmitted to the first gear portion 14. This first gear portion 14 meshes with a second gear portion 28 of an MG1 shaft 26 that constitutes a part of a first electric motor 20 (see FIG. 3). The MG1 shaft 26 is disposed along the vehicle width direction and rotatably supported by bearings 18, and the second gear portion 28 is formed on the outer periphery of the MG1 shaft 26. As shown in FIG. 1, the MG1 shaft 26 is provided above and to the side of the input shaft 12.

[0028] The oil pump 60 is used to pump out oil stored in the oil reservoir 44. As shown in FIG. 2, the oil pump 60 has a pump operating portion 62 for pumping oil, which is connected to one axial end of the input shaft 12. The pump operating portion 62 is provided in an oil passage 100 (see FIG. 1; in FIG. 1, a passage through which oil flows as indicated by arrows A1, A2, and A3). The pump operating portion 62 is a pump gear, and is configured to rotate by the rotational drive of the engine (not shown) and pump out oil.

[0029] 1, oil pump 60 has a pump cover 64 that forms a cover. The outer periphery of pump cover 64 is attached to casing 40 using fastening members such as bolts, and the lower part is connected to strainer 68. Pump cover 64 extends toward oil cooler 80, including the portion immediately above input shaft 12, as viewed in width direction W of transaxle 10 (as viewed from the front Fr side). The upper end of pump cover 64 is located immediately above MG1 shaft 26, as an example, as viewed in width direction W of transaxle 10 (as viewed from the front Fr side), and reaches ceiling portion 40A of casing 40.

[0030] A groove-shaped recess 64A is formed in the surface of the pump cover 64 facing the rear Rr side (the back side of the paper in FIG. 1). This recess 64A forms part of the oil passage 100. Although not shown, the internal space of the recess 64A of the pump cover 64 and the internal space of the oil cooler 80 are connected via a connecting passage (part of the oil passage 100) not shown. The oil cooler 80 is a heat exchanger that is provided in the oil passage 100 to cool the oil, and the entire oil cooler 80 is located above the MG1 shaft 26 and attached to the casing 40.

[0031] A relief valve 70 is provided in the pump cover 64, and the internal space of the relief valve 70 communicates with the internal space of the recess 64A of the pump cover 64. The relief valve 70 is provided to prevent the oil pressure in the oil passage 100 from becoming excessive, and is configured to discharge oil from the oil passage 100 when the oil pressure in the oil passage 100 exceeds a predetermined value.

[0032] The relief valve 70 is disposed above the input shaft 12 and on the input shaft 12 side of the MG1 shaft 26. This point will be described in detail. In this embodiment, the relief valve 70 is disposed directly above the input shaft 12. The relief valve 70 is also disposed directly beside the MG1 shaft 26, and is disposed on the input shaft 12 side (here, on the vehicle rear side) of the MG1 shaft 26 in the left-right direction (vehicle front-rear direction) when viewed in the width direction W of the transaxle 10 (viewed from the front Fr side). The distance from the relief valve 70 to the MG1 shaft 26 is set shorter than the distance from the relief valve 70 to the input shaft 12.

[0033] In addition, below the relief valve 70 and on the opposite side of the MG1 shaft 26 with respect to an imaginary line (not shown) passing through the relief valve 70 and the input shaft 12 when viewed from the width direction W of the transaxle 10 (when viewed from the front Fr side), a parking member (sometimes referred to as a "parking part") 90 that constitutes a parking lock mechanism is arranged.

[0034] The relief valve 70 includes a cylindrical portion 72, a relief hole 74 formed through the cylindrical portion 72, and an opening / closing body 76 that is slidable within the cylindrical portion 72 in the direction of its central axis and that is capable of opening and closing the relief hole 74. A known mechanism such as a spring mechanism can be applied to the mechanism that controls the position of the opening / closing body 76 in response to the oil pressure, and therefore a detailed description thereof will be omitted.

[0035] As an example, three relief holes 74 are formed in total, facing the input shaft 12, the MG1 shaft 26, and the parking member 90, respectively. That is, the relief valve 70 is configured to be able to discharge oil toward the input shaft 12, the MG1 shaft 26, and the parking member 90. Note that gear portions (specifically, the first gear portion 14, the second gear portion 28, etc.) provided on the input shaft 12, the MG1 shaft 26, and the parking member 90, respectively, and bearings (specifically, the bearings 16A, 16B, 18, etc. shown in FIG. 2) that rotatably support the input shaft 12, the MG1 shaft 26, and the parking member 90, respectively, are parts that are subject to lubrication with oil. Furthermore, the input shaft 12, the MG1 shaft 26, and the parking member 90 are located within ranges that are covered by oil when the relief valve 70 discharges oil.

[0036] (Actions and Effects of the Embodiments) Next, the operation and effects of this embodiment will be described.

[0037] In this embodiment, when the pump operating portion 62 of the oil pump 60 shown in FIG. 2 is rotated by the rotational drive of the engine (not shown), oil is pumped out. At this time, the oil stored in the oil reservoir 44 shown in FIG. 1 is sucked by the strainer 68, flows through the oil passage 100 as shown by arrows A1, A2, and A3, reaches the oil cooler 80, and is cooled by the oil cooler 80. Furthermore, the oil that has passed through the oil cooler 80 shown in FIG. 3 flows through the oil passage 100 as shown by arrows A4, A5, and A6, is sprayed from the first pipe 101 onto the first electric motor 20, and is further sprayed from the second pipe 102 onto the second electric motor 30. This cools the first electric motor 20 and the second electric motor 30. The oil used for cooling the first electric motor 20 and the second electric motor 30, etc., passes through a passage (not shown) that penetrates the motor chamber 41 and the gear chamber 42 (see Figure 1) from the motor chamber 41 shown in Figure 3 to the gear chamber 42 shown in Figure 1, and returns to the oil reservoir 44.

[0038] Furthermore, when the oil pressure in the oil passage 100 exceeds a predetermined value, a relief valve 70 provided in the pump cover 64 opens, and oil is discharged into the gear chamber 42. In this embodiment, the relief valve 70 is disposed above the input shaft 12 and on the input shaft 12 side of the MG1 shaft 26, enabling oil to be discharged toward the input shaft 12 and the MG1 shaft 26. Therefore, when the relief valve 70 opens, oil is discharged (sprayed) from the relief valve 70 toward the input shaft 12 and the MG1 shaft 26. Therefore, there is no need to provide a separate oil passage for supplying oil to the input shaft 12 and the MG1 shaft 26.

[0039] The supply of oil from the relief valve 70 to the input shaft 12 and the MG1 shaft 26 will be described in more detail. In this embodiment, the relief valve 70 is disposed directly above the input shaft 12, so that oil can be reliably supplied to the input shaft 12 by letting the oil drop from the relief valve 70. On the other hand, oil cannot be supplied to the MG1 shaft 26 simply by letting the oil drop from the relief valve 70. However, since the distance from the relief valve 70 to the MG1 shaft 26 is set shorter than the distance from the relief valve 70 to the input shaft 12, oil can be supplied to the MG1 shaft 26 effectively. In this embodiment, the relief valve 70 is disposed directly beside the MG1 shaft 26, for example. Therefore, oil can be supplied from the relief valve 70 to the MG1 shaft 26 from directly beside the MG1 shaft 26.

[0040] Furthermore, in this embodiment, a parking member 90 is disposed below the relief valve 70 and on the opposite side of the MG1 shaft 26 with respect to an imaginary line (not shown) passing through the relief valve 70 and the input shaft 12 when viewed in the width direction W of the transaxle 10, and the relief valve 70 is capable of discharging oil toward the parking member 90. Therefore, when the relief valve 70 is opened, oil is also discharged from the relief valve 70 toward the parking member 90. Therefore, there is no need to provide a separate oil passage for supplying oil to the parking member 90.

[0041] Furthermore, in this embodiment, the oil cooler 80 is disposed at a position above the MG1 shaft 26, and the pump cover 64 forming part of the oil passage 100 includes a portion directly above the input shaft 12 when viewed from the width direction W of the transaxle 10, extends toward the oil cooler 80, and reaches the ceiling portion 40A of the casing 40. This makes it possible to simplify the oil passages provided in the upper part to cool the first electric motor 20 and the second electric motor 30 (both see FIG. 3 ), and also simplifies the oil passage for circulating oil pressurized by the oil pump 60 to the oil cooler 80.

[0042] As described above, according to the transaxle 10 of this embodiment, the configuration of the oil passage 100 can be simplified. As a result, costs can be reduced. Furthermore, by effectively using the oil discharged from the relief valve 70 for lubrication, the workload of the oil pump 60 can be reduced, resulting in improved fuel economy.

[0043] (Supplementary explanation of the embodiment) In the above embodiment, the relief valve 70 is configured to be able to discharge oil toward the parking member 90, and such a configuration is preferable. However, as a variation of the above embodiment, the relief valve may be configured not to be able to discharge oil toward the parking member (90).

[0044] In addition, in the above embodiment, the relief valve 70 is disposed directly above the input shaft 12, and this configuration is preferable. However, as a modification of the above embodiment, the relief valve may be disposed diagonally above the input shaft 12.

[0045] Furthermore, in the above embodiment, the relief valve 70 is disposed directly to the side of the MG1 shaft 26 when viewed from the width direction W of the transaxle 10. However, as a modification of the above embodiment, the relief valve may be disposed diagonally above and to the side of the MG1 shaft (26) when viewed from the width direction (W) of the transaxle (10).

[0046] In addition, in the above embodiment, the distance from the relief valve 70 to the MG1 shaft 26 is set to be shorter than the distance from the relief valve 70 to the input shaft 12, and such a configuration is preferable. However, as a modification of the above embodiment, a configuration in which the distance from the relief valve (70) to the MG1 shaft (26) is set to be equal to or greater than the distance from the relief valve (70) to the input shaft (12) may also be adopted.

[0047] Furthermore, although the transaxle 10 of the above embodiment is applied to a series hybrid vehicle, the transaxle of the present invention may also be applied to a parallel hybrid vehicle.

[0048] The above-described embodiment and the above-described modifications can be implemented in appropriate combinations.

[0049] Although one example of the present invention has been described above, the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms within the scope of the gist of the present invention. [Explanation of symbols]

[0050] 10 Transaxle 12 Input Axis 14 First gear section 26 MG1 shaft (electric motor shaft) 28 Second gear section 60 Oil pump 62 Pump operating section 64 Pump cover 70 Relief valve 90 Parking parts 100 Oil road

Claims

1. an input shaft having a first gear portion to which the output of the engine is transmitted; an electric motor shaft having a second gear portion that meshes with the first gear portion of the input shaft and that is provided above and to the side of the input shaft; an oil pump having a pump operating portion for pumping oil, the pump operating portion being provided in an oil passage for supplying oil to a portion requiring lubrication or cooling and connected to one axial end side of the input shaft, and having a pump cover that forms a cover and forms a part of the oil passage; a relief valve provided in the pump cover and configured to discharge oil from the oil passage when the oil pressure in the oil passage exceeds a predetermined value, the relief valve being disposed above the input shaft and on one of the lateral sides of the electric motor shaft closer to the input shaft, and capable of discharging oil toward the input shaft and the electric motor shaft; A transaxle comprising:

2. 2. The transaxle according to claim 1, wherein a parking member constituting a parking lock mechanism is disposed below the relief valve and on the opposite side of the electric motor shaft with respect to an imaginary line passing through the relief valve and the input shaft when viewed from the same direction as the axial direction of the input shaft, and the relief valve is configured to be able to discharge oil toward the parking member.

3. The relief valve is disposed directly above the input shaft, 3. The transaxle according to claim 1, wherein a distance from the relief valve to the electric motor shaft is set shorter than a distance from the relief valve to the input shaft.

4. 3. The transaxle according to claim 1, wherein the relief valve is disposed immediately to the side of the electric motor shaft.

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