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 Art

[0002] The following Patent Document 1 discloses a technique related to a transaxle having an oil passage for oil conveyed from an oil pump. In this prior art, it has a pump cover that forms the cover of the oil pump and a part of the oil passage, and a relief valve provided on the pump cover that discharges oil from the oil passage according to the pressure of the oil passage. According to such a configuration, it is not necessary to separately provide a member for forming an oil passage for relief inside the casing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in this prior art, 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 simplifying the configuration of the oil passage.

[0005] In consideration of the above facts, an object of the present invention is to obtain a transaxle capable of simplifying the configuration of the oil passage.

Means for Solving the Problems

[0006] The transaxle of the present invention as described in claim 1 comprises: an input shaft having a first gear portion on 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 provided above and to the side of the input shaft; an oil pump having an oil pump operating unit provided in an oil passage for supplying oil to a place where lubrication or cooling is required and connected to one axial end of the input shaft, and a pump cover that forms a cover and forms part of the oil passage; and 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, and positioned above the input shaft and to the side of the electric motor shaft on the input shaft side, and capable of discharging oil toward the input shaft and the electric motor shaft. Furthermore, a parking member constituting the parking lock mechanism is positioned on the opposite side from the motor shaft side of a virtual straight 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 discharge oil toward the parking member.

[0007] According to the above configuration, the engine output is transmitted to the first gear section of the input shaft. The motor shaft, located above and to the side of the input shaft, has a second gear section that meshes with the first gear section of the input shaft. The oil pump has a pump operating section and a pump cover. The pump operating section is for oil pumping and is located in an oil passage for supplying oil to areas requiring lubrication or cooling, and is connected to one axial end of the input shaft. The pump cover forms part of the oil passage. A relief valve provided in the pump cover is configured to discharge oil from the oil passage when the oil pressure in the oil passage exceeds a predetermined value. It is located above the input shaft and to the side of the motor shaft, on the input shaft side, and is capable of discharging oil toward both the input shaft and the motor shaft. Therefore, there is no need to provide separate oil passages for supplying oil to the input shaft and the motor shaft. Furthermore, the parking lock mechanism is positioned on the opposite side of the motor shaft from the virtual straight 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. Therefore, there is no need to provide a separate oil passage to supply oil to the parking member.

[0008] The transaxle of the present invention as described in claim 2 has the configuration described in claim 1, The parking member is, Lower side of the relief valve to Placed Yes, they are.

[0009] According to the above configuration, The parking element is positioned below the relief valve, and the relief valve is capable of discharging oil towards the parking element located below it.

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

[0011] With the above configuration, the relief valve is positioned directly above the input shaft, so oil can be reliably supplied to the input shaft by letting oil fall from the relief valve. On the other hand, oil cannot be supplied to the motor shaft by letting oil fall from the relief valve alone, but since the distance from the relief valve to the motor shaft is set to be shorter than the distance from the relief valve to the input shaft, oil can be supplied to the motor shaft effectively.

[0012] The transaxle of the present invention as described in claim 4 has the configuration described in claim 1 or claim 2, wherein the relief valve is positioned directly lateral to the motor shaft.

[0013] With the above configuration, oil can be supplied from the relief valve to the motor shaft from directly beside the 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 drawing]

[0015] [Figure 1] This is a simplified perspective view showing a transaxle according to one embodiment of the present invention, with the engine-side case removed. [Figure 2]It is a cross-sectional view showing an enlarged state of a transaxle cut along a cutting line corresponding to the 2-2 line in FIG. 1. [Figure 3] It is a perspective view showing a simplified motor chamber side of the transaxle.

Embodiment for Carrying out the Invention

[0016] The transaxle according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

[0017] (Configuration of the Embodiment) FIG. 1 is a perspective view showing a simplified state of a transaxle 10 according to the present 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 can be driven by driving a first electric motor 20 using the engine as a power source and driving a second electric motor 30 by driving the first electric motor 20, and can also travel by stopping the engine and driving the second electric motor 30 using the battery as a power source. It is a so-called series hybrid vehicle.

[0018] In addition, the arrow UP in the figure indicates the upper side in the state where the transaxle 10 is mounted on the vehicle. Further, in the following description, in the input direction from the engine (not shown) (the axial direction of the input shaft 12 described later), the front side when viewing the transaxle 10 from the engine side may be described as "front Fr" and the rear side as "rear Rr". Furthermore, the arrow W shown in FIG. 1 and the like 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] The transaxle 10 shown in FIG. 1 includes a casing 40, a first electric motor (also referred to as "MG1") 20, a second electric motor (also referred to as "MG2") 30, and a differential mechanism (not shown). Further, the transaxle 10 is provided with an oil pump 60, a strainer 68, a relief valve 70, an oil cooler 80, and the like.

[0020] The casing 40, as an example, forms a housing with three members arranged in the width direction W of the transaxle 10. In FIG. 1, a member (T / A case) that constitutes the middle portion in the width direction W of the three members is shown. Supplementary explanation: In the casing 40, the front Fr side is composed of a case (also referred to as a housing, not shown) having an opening on the middle portion side in the width direction W of the casing 40, and the rear Rr side is composed of a cover (not shown) having an opening on the middle portion side in the width direction W of the casing 40. The internal space of the casing 40 is partitioned by a partition wall 43 shown in FIG. 1 into a motor chamber 41 on the rear Rr side (see FIG. 3) 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). In the gear chamber 42, an input shaft 12, an MG1 shaft 26 serving as an electric motor shaft described later, and the like are arranged.

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

[0022] The transaxle 10 has oil passages 100 for supplying oil to areas requiring lubrication or cooling. In Figure 1, the flow of oil from the oil passages 100 to the oil cooler 80 is shown by arrows A1, A2, and A3, and in Figure 3, the flow of oil from the oil cooler 80 through the oil passages 100, viewed from the opposite side of Figure 1, is shown by arrows A4, A5, and A6. In other words, in Figure 1, the oil passages 100 are passages through which oil flows as shown by arrows A1, A2, and A3, and in Figure 3, the oil passages 100 are passages through which oil flows as shown by arrows A4, A5, and A6. The oil passages 100 consist of a portion formed by multiple through holes and recesses formed in the casing 40 shown in Figure 1, etc., and a portion formed by a member such as a strainer 68. In addition, various components of the transaxle 10 are lubricated or cooled by the oil.

[0023] As shown in Figure 3, the upper oil passage 100A, which is connected to the oil cooler 80 as part of the oil passage 100, extends in the direction in which the first motor 20 and the second motor 30 are aligned, at a position above the first motor 20 and the second motor 30. Directly above the first motor 20, there is a first pipe 101 connected to the upper oil passage 100A and protruding towards the rear Rr side, and directly above the second motor 30, there is a second pipe 102 connected to the upper oil passage 100A and protruding towards the rear Rr side. That is, the oil ejected from the first pipe 101 is configured to hit the first motor 20, and the oil ejected from the second pipe 102 is configured to hit the second 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 motor 20 and the second motor 30 back to the oil reservoir 44 (see Figure 1), a passage (not shown) is formed through the motor chamber 41 and the gear chamber 42 shown in Figure 1.

[0024] The first motor 20 shown in Figure 3 consists of a motor generator. A generator controller with a built-in inverter is connected to the first motor 20. The AC power output from the first motor 20 is converted to DC power by the generator controller, and this DC power is supplied to the battery, thereby charging the battery. The first motor 20 is configured to be driven by rotational power transmitted from the engine (not shown).

[0025] The second motor 30 consists of a motor generator. A motor controller, which has a built-in inverter, is connected to the second motor 30. A battery is connected to the motor controller. The DC power output from the battery is supplied to the motor controller, which converts it into AC power, and this AC power is then supplied to the second motor 30, thereby driving the second motor 30.

[0026] Figure 2 shows a magnified view of the transaxle 10 cut along the cutting line corresponding to line 2-2 in Figure 1. In Figure 2, hatching is applied to the cut surfaces of the input shaft 12, MG1 shaft 26, bearings 16A, 16B, and 18 (described later), and the pump operating section 62 (described later), but hatching is omitted from the cut surfaces of other parts for convenience.

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

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

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

[0030] A groove-shaped recess 64A is formed on the surface of the pump cover 64 facing the rear Rr side (the back side in Figure 1). This recess 64A forms part of the oil passage 100. Although not shown, the internal space of the recess 64A in 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), which is not shown. The oil cooler 80 is a heat exchanger installed in the oil passage 100 to cool the oil, and its entirety is positioned above the MG1 shaft 26 and attached to the casing 40.

[0031] The pump cover 64 is provided with a relief valve 70, and the internal space of the relief valve 70 is connected to 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 located above the input shaft 12 and on the side of the MG1 shaft 26 that is on the input shaft 12 side. This point will be explained in detail. In this embodiment, the relief valve 70 is located directly above the input shaft 12. The relief valve 70 is also located directly beside the MG1 shaft 26, and when viewed from the width direction W of the transaxle 10 (viewed from the front Fr side), it is located on the input shaft 12 side (in this case, the rear side of the vehicle) relative to the MG1 shaft 26 in the left-right direction (vehicle longitudinal direction). 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.

[0033] Furthermore, a parking member (sometimes referred to as a "parking component") 90, which constitutes the parking lock mechanism, is positioned below the relief valve 70 and on the opposite side from the MG1 shaft 26 side to a virtual straight 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 (viewed from the front Fr side).

[0034] The relief valve 70 comprises 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 capable of opening and closing the relief hole 74. Regarding the mechanism for controlling the position of the opening / closing body 76 according to the oil pressure, a known mechanism such as a spring mechanism can be applied, so a detailed explanation is omitted.

[0035] Three relief holes 74 are formed, for example, so as to face the positions of the input shaft 12, the MG1 shaft 26, and the parking member 90. In other words, the relief valve 70 is configured to discharge oil toward the input shaft 12, the MG1 shaft 26, and the parking member 90. The gear parts provided on the input shaft 12, the MG1 shaft 26, and the parking member 90 (specifically the first gear part 14, the second gear part 28, etc.), as well as the bearings that rotatably support the input shaft 12, the MG1 shaft 26, and the parking member 90 (specifically the bearings 16A, 16B, 18, etc. shown in Figure 2), are parts that are lubricated by oil. Furthermore, the input shaft 12, the MG1 shaft 26, and the parking member 90 are located within the range where oil will reach them when the relief valve 70 discharges oil.

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

[0037] In this embodiment, when the pump operating section 62 of the oil pump 60 shown in Figure 2 rotates due to the rotational drive of the engine (not shown), oil is pumped under pressure. At this time, the oil stored in the oil reservoir 44 shown in Figure 1 is sucked in by the strainer 68 and flows through the oil passage 100 as indicated by arrows A1, A2, and A3 to reach the oil cooler 80, where it is cooled. Furthermore, the oil that has passed through the oil cooler 80 shown in Figure 3 flows through the oil passage 100 as indicated by arrows A4, A5, and A6, and is ejected from the first pipe 101 onto the first motor 20, and then ejected from the second pipe 102 onto the second motor 30. As a result, the first motor 20 and the second motor 30 are cooled. The oil used for cooling the first motor 20 and the second motor 30 enters the gear chamber 42 shown in Figure 1 from the motor chamber 41 shown in Figure 3 through a passage (not shown) that penetrates the motor chamber 41 and the gear chamber 42 (see Figure 1), and returns to the oil reservoir 44.

[0038] Furthermore, if the oil pressure in the oil passage 100 exceeds a predetermined value, the relief valve 70 provided on the pump cover 64 opens, and oil is discharged into the gear chamber 42. In this embodiment, the relief valve 70 is located above the input shaft 12 and on the side of the MG1 shaft 26, on the input shaft 12 side, allowing 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. For this reason, there is no need to provide a separate oil passage to supply 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, since the relief valve 70 is positioned directly above the input shaft 12, oil can be reliably supplied to the input shaft 12 by letting oil fall from the relief valve 70. On the other hand, oil cannot be supplied to the MG1 shaft 26 by letting oil fall from the relief valve 70 alone, but since 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, oil can be supplied to the MG1 shaft 26 effectively. In addition, in this embodiment, as an example, the relief valve 70 is positioned directly beside the MG1 shaft 26. 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, the parking member 90 is positioned below the relief valve 70 and on the opposite side from the MG1 shaft 26 side with respect to a virtual straight 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, 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. For this reason, 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 positioned above the MG1 shaft 26, and the pump cover 64, which forms part of the oil passage 100, extends toward the oil cooler 80, including the portion directly above the input shaft 12 when viewed from the width direction W of the transaxle 10, and reaches the ceiling portion 40A of the casing 40. As a result, the oil passages provided above to cool the first motor 20 and the second motor 30 (see Figure 3 for both) can be simplified, and the oil passages for circulating the oil pressurized by the oil pump 60 to the oil cooler 80 can also be simplified.

[0042] As described above, the transaxle 10 of this embodiment simplifies the configuration of the oil passage 100. As a result, costs can be reduced. Furthermore, by effectively utilizing the oil discharged from the relief valve 70 for lubrication, the workload of the oil pump 60 can be reduced, enabling improved fuel efficiency.

[0043] (Supplementary explanation of the embodiment) In the above embodiment, the relief valve 70 is configured to discharge oil toward the parking member 90, and such a configuration is preferred, Reference Examples Not Concerning Embodiments of the Invention Alternatively, the relief valve may be configured in such a way that it cannot discharge oil toward the parking member (90).

[0044] Furthermore, in the above embodiment, the relief valve 70 is positioned directly above the input shaft 12, and this configuration is preferred. However, as a modification of the above embodiment, a configuration in which the relief valve is positioned diagonally above the input shaft (12) is also possible.

[0045] Furthermore, in the above embodiment, the relief valve 70 is positioned 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 also be positioned diagonally above and to the side of the MG1 shaft (26) when viewed from the width direction (W) of the transaxle (10).

[0046] Furthermore, 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 preferred. However, as a modification of the above embodiment, a configuration can also be adopted in which the distance from the relief valve (70) to the MG1 shaft (26) is set to be greater than or equal to the distance from the relief valve (70) to the input shaft (12).

[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] Furthermore, the above embodiments and the various modifications described above can be combined as appropriate.

[0049] Although an example of the present invention has been described above, the present invention is not limited to the above, and it is of course possible to implement it in various modified forms without departing from its spirit. [Explanation of Symbols]

[0050] 10 transaxles 12 Input axes 14. First Gear Section 26 MG1 shaft (motor shaft) 28 Second Gear Section 60 Oil pump 62 Pump operating section 64 Pump Cover 70 Relief Valve 90 Parking components 100 Oil road

Claims

1. An input shaft having a first gear section through which engine power is transmitted, A motor shaft having a second gear portion that meshes with the first gear portion of the input shaft, and provided above and to the side of the input shaft, An oil pump having an oil pump operating unit for oil pressurization, which is provided in an oil passage for supplying oil to a part requiring lubrication or cooling and is connected to one axial end of the input shaft, and a pump cover which forms a part of the oil passage, A relief valve is 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, and is positioned above the input shaft and on the side of the motor shaft that is on the input shaft side, and is capable of discharging oil toward the input shaft and the motor shaft. Equipped with, A transaxle in which a parking lock mechanism is positioned on the opposite side from the motor shaft side of a virtual straight 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 discharge oil toward the parking member.

2. The transaxle according to claim 1, wherein the parking member is located below the relief valve.

3. The relief valve is positioned directly above the input shaft. The transaxle according to claim 1 or claim 2, wherein the distance from the relief valve to the motor shaft is set to be shorter than the distance from the relief valve to the input shaft.

4. The transaxle according to claim 1 or 2, wherein the relief valve is positioned directly lateral to the motor shaft.

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