Lubricating structure of vehicle

Abstract

The present application relates to a lubrication structure of a vehicle, including: a first lubrication pipe supplying lubricating oil to a rotating machine arranged in a housing; a second lubrication pipe supplying lubricating oil to a bearing member arranged in the housing; and an oil pump supplying lubricating oil to the first lubrication pipe and the second lubrication pipe. In the lubrication structure of the vehicle, a first oil hole provided in the housing and to which the first lubrication pipe is connected, and a second oil hole provided in the housing and through which lubricating oil flows from the second lubrication pipe are equipped, and the connection portion is positioned at a position higher than an opening portion of the second oil hole so as to cause at least a part of the lubricating oil flowing out from the connection portion of the first lubrication pipe and the first oil hole to flow into the second oil hole.

Description

Technical Field

[0001] The present invention relates to a lubrication structure for vehicles, and in particular, to a lubrication structure for supplying lubricating oil from respective pipes to rotating machinery and bearing components. Background Technology

[0002] A lubrication structure for a vehicle is known, comprising a first lubrication pipe supplying lubricating oil to a rotating mechanism disposed within a housing, a second lubrication pipe supplying lubricating oil to a bearing component disposed within the housing, and an oil pump supplying lubricating oil to both the first and second lubrication pipes. For example, Japanese Patent Application Publication No. 2019-162927 discloses a lubrication structure for a hybrid electric vehicle, (a) wherein the hybrid electric vehicle is equipped with: an engine (engine 10), a power transmission device, and a rotating mechanism for travel (second electric motor MG2), the power transmission device transmitting driving force from the engine to the drive wheels via an output unit (differential 24, etc.), the rotating mechanism for travel being connected to the output unit, and the lubrication structure comprising: (b) housing the power transmission device and the rotating mechanism within a housing. The engine comprises: (c) a housing [housing 60]; (d) an I / P pump [input shaft MOP51] mechanically driven by the engine to discharge lubricating oil; (e) an O / P pump [output shaft MOP52] connected to the output unit and mechanically driven to discharge lubricating oil; (f) an I / P oil passage [first oil passage 71] connected to the discharge side of the I / P pump and supplying lubricating oil to the rotating mechanism; and (c) an O / P oil passage [second oil passage 72] connected to the discharge side of the O / P pump and supplying lubricating oil to the power transmission device [reduction gear 56, etc.]. The I / P oil passage is constructed using a first lubrication piping as needed, and the O / P oil passage is constructed using a second lubrication piping as needed. Furthermore, for the bearing components of each part, lubricating oil is mainly supplied from the O / P oil passage. Furthermore, Japanese Patent Application Publication No. 2014-119085 discloses a lubrication structure in which lubricating oil carried by the main reducer is guided by an oil guide member and an oil groove. ー It is supplied to the lubrication parts of planetary gear mechanisms, etc.

[0003] In addition, the term "lubrication" in this manual refers not only to preventing friction or wear, but also to the supply of lubricating oil to rotating machines and the like for cooling. Summary of the Invention

[0004] However, in the lubrication system of such vehicles, when the viscosity of the lubricating oil increases at extremely low temperatures, there is a possibility of insufficient lubrication supply to the bearing components, leading to burn-out. This phenomenon is particularly pronounced in the lubrication system described in Japanese Patent Application Publication No. 2014-119085, which uses a pump-assisted lubrication method. Furthermore, in the lubrication system described in Japanese Patent Application Publication No. 2019-162927, which uses a pump to supply lubricating oil, from the viewpoint of power transmission efficiency, since the amount of oil supplied to bearing components is designed not to be excessive, there is also a possibility of insufficient oil supply at extremely low temperatures.

[0005] This invention provides a simple method for supplying lubricating oil to rotating machines and bearing components from their respective piping, enabling a stable supply of lubricating oil to bearing components even in extremely low temperature environments.

[0006] According to one aspect of the present invention, a lubrication structure for a vehicle includes: a first lubrication pipe supplying lubricating oil to a rotating machine disposed within a housing; a second lubrication pipe supplying lubricating oil to a bearing member disposed within the housing; and an oil pump supplying lubricating oil to both the first and second lubrication pipes. The lubrication structure of the vehicle is equipped with: (a) a first oil hole, provided in the housing for supplying lubricating oil to the rotating machine, to which the first lubrication pipe is connected; and (b) a second oil hole, provided in the housing for supplying lubricating oil to the bearing member, to which lubricating oil flows from the second lubrication pipe into the second oil hole; and (c) a connection portion positioned above the opening of the second oil hole so that at least a portion of the lubricating oil flowing from the connection portion of the first lubrication pipe and the first oil hole flows into the second oil hole.

[0007] In such a vehicle lubrication structure, since the connection between the first lubrication pipe supplying lubricating oil to the rotating machine and the first oil hole is positioned above the opening of the second oil hole from which lubricating oil flows from the second lubrication pipe supplying lubricating oil to the bearing components, at least a portion of the lubricating oil flowing out from the connection flows into the second oil hole. Therefore, insufficient lubricating oil supply to the bearing components is suppressed at extremely low temperatures where the lubricating oil viscosity is high. Furthermore, since it is only necessary to allow lubricating oil to flow out from the connection between the first lubrication pipe and the first oil hole, and to position the opening of the first oil hole above the opening of the second oil hole, it can be easily implemented without significant design changes. Moreover, compared to the case where the oil pump supplying lubricating oil to the second lubrication pipe is enlarged to ensure a sufficient amount of lubricating oil is supplied to the bearing components even at extremely low temperatures, it can be constructed at a lower cost.

[0008] In the lubrication structure of the vehicle according to the above method, the first lubrication pipe can also be loosely fitted with the first oil hole in a state where sealing components such as O-rings are not clamped in the connection part, but have a specified gap, so that even at extremely low temperatures where the viscosity of the lubricating oil is high, the lubricating oil will leak out and flow down from the connection part.

[0009] Since the first lubrication pipe can be loosely fitted to the first oil hole without the use of sealing components such as O-rings and with a specified gap, so that lubricating oil can leak out and flow down from the connection between the first lubrication pipe and the first oil hole, it can be implemented simply and cheaply.

[0010] In the lubrication structure of the vehicle according to the above method, an upwardly extending V-shaped or U-shaped oil receiver may also be provided at the opening of the second oil hole, and the connecting portion is positioned at least partially overlapping the oil receiver in the vertical direction.

[0011] Because a V-shaped or U-shaped oil receiver is provided at the opening of the second oil hole, and the connecting part is positioned such that at least a portion overlaps with the oil receiver in the vertical direction, at least a portion of the lubricating oil flowing down from the connecting part is blocked by the oil receiver and reliably flows into the second oil hole, thus properly suppressing the insufficient supply of lubricating oil to the bearing component.

[0012] In the lubrication structure of the vehicle according to the above method, (a) the vehicle may also be a hybrid electric vehicle equipped with: an engine; a power transmission device that transmits the driving force from the engine to the drive wheels via an output section; and a driving rotary machine connected to the output section; (b) the power transmission device and the driving rotary machine are housed within the housing, and the driving rotary machine is the rotary machine. For supporting a predetermined rotating component of either the power transmission device or the driving rotary machine, a... The bearing assembly is provided. On the other hand, (c) the oil pump is equipped with an I / P (input) pump that is mechanically driven to rotate by the engine to discharge lubricating oil, and an O / P (output) pump that is connected to the output section and is mechanically driven to rotate to discharge lubricating oil. (d) Lubricating oil can also be supplied from the I / P pump to the first lubrication pipe for cooling the stator of the traveling rotary machine. On the other hand, lubricating oil can be supplied from the O / P pump to the second lubrication pipe for lubricating the bearing assembly.

[0013] In the case of the lubrication structure of a hybrid electric vehicle, an I / P pump mechanically driven by the engine and an O / P pump mechanically driven by the output are provided. When lubricating oil is supplied from the I / P pump to the first lubrication pipe and from the O / P pump to the second lubrication pipe, a portion of the lubricating oil discharged from the I / P pump flows into the second oil hole and is supplied to the bearing components. Thus, without having to increase the size of the O / P pump, insufficient lubricating oil supply to the bearing components at extremely low temperatures can be suppressed. Moreover, although the discharge volume of the O / P pump decreases at low vehicle speeds, and the amount of lubricating oil supplied to the bearing components from the second lubrication pipe decreases, the insufficient lubricating oil supply to the bearing components at low vehicle speeds is also suppressed by allowing a portion of the lubricating oil supplied from the I / P pump to the first lubrication pipe to flow out from the connection with the first oil hole and into the second oil hole.

[0014] In the lubrication structure according to the above method, the discharge capacity of the I / P pump can also be larger than that of the O / P pump.

[0015] The discharge capacity mentioned above is the amount of lubricating oil discharged per revolution.

[0016] When the discharge capacity of the I / P pump is larger than that of the O / P pump, the viscosity of the lubricating oil has a smaller impact on the I / P pump with a larger discharge capacity. Therefore, even at extremely low temperatures where the viscosity increases, a sufficient amount of lubricating oil can be supplied to the rotating machine for proper cooling. Furthermore, by having a portion of the lubricating oil flow into the second oil hole and supply it to the bearing components, the effect of suppressing insufficient lubricating oil supply to the bearing components can be appropriately achieved without increasing the size of the O / P pump.

[0017] In the lubrication structure according to the above method, the opening of the second oil hole may also be offset from directly below the connecting part, and an inclined groove-shaped oil guide is provided directly below the connecting part, the oil guide guiding at least a portion of the lubricating oil flowing out from the connecting part into the second oil hole. Attached Figure Description

[0018] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which similar reference numerals denote similar parts, wherein:

[0019] Figure 1 This is an architectural diagram illustrating a hybrid electric vehicle having a lubrication structure incorporating the present invention, and is an unfolded diagram showing the arrangement of multiple shafts of the power transmission device in a common plane.

[0020] Figure 2 This is an explanation Figure 1A diagram showing the outline of a vehicle lubrication system used as a lubrication structure in a hybrid electric vehicle.

[0021] Figure 3 It is a specific explanation Figure 2 The three-dimensional diagram of the power transmission device of the vehicle lubrication system is a diagram that omits the transmission drive axle housing.

[0022] Figure 4 It is an explanation of the composition Figure 2 The front view shows the state in which the I / P oil pump and O / P oil pump of the vehicle's lubrication system are installed in the partition wall of the transmission drive axle housing.

[0023] Figure 5 It is an enlarged representation Figure 4 Part of the transmission drive axle housing, namely the I / P oil pump, is connected to the connecting oil port. Figure 4 A 3D view of the upper left part.

[0024] Figure 6 It is equivalent to Figure 5 The sectional view of the power transmission device in the VI-VI direction is a diagram illustrating the bearing structure of the rotor shaft and gear shaft arranged on the third axis S3, and the connection structure of the I / P oil pump connected above the third axis S3.

[0025] Figure 7 These are diagrams illustrating other embodiments of the present invention, corresponding to... Figure 5 A three-dimensional image.

[0026] Figure 8 The figures illustrate further embodiments of the present invention and correspond to... Figure 2 A schematic diagram of a vehicle lubrication system. Detailed Implementation

[0027] This invention is applicable to various vehicles having a first lubrication pipe supplying lubricating oil to a rotating machine, a second lubrication pipe supplying lubricating oil to bearing components, and an oil pump. The rotating machine is an electric motor, a generator, or an electric generator that functions as both. That is, this invention can be applied to the lubrication structures of various vehicles, such as engine-driven vehicles equipped with an engine (internal combustion engine) as a driving force source, parallel or series hybrid electric vehicles equipped with an engine and a rotating machine, or electric vehicles driven by an electric motor powered by a power source such as a battery. The first lubrication pipe supplying lubricating oil to the rotating machine is, for example, configured to supply lubricating oil to the stator of the rotating machine for cooling; however, it can also supply lubricating oil to the rotor shaft of the rotating machine or the bearing components of that rotor shaft. The second lubrication pipe supplies lubricating oil to a location different from the first lubrication pipe. In the case where the first lubrication pipe supplies lubricating oil to the bearing components of the rotor shaft, the second lubrication pipe is configured to supply lubricating oil to the bearing components of a rotating part different from the rotor shaft. In addition to rolling bearings such as ball bearings or roller bearings that support rotation around an axis, the bearing components can also be sliding bearings or thrust bearings.

[0028] Oil pumps may be individually installed in each of the first and second lubrication lines, but alternatively, lubricating oil discharged from a common single oil pump may be supplied to both the first and second lubrication lines via a branch. The oil pump may be a mechanical pump driven by a predetermined rotating component in the engine or power transmission path, or an electric pump driven by a dedicated electric motor. When multiple oil pumps are provided, their discharge capacities may differ or be the same.

[0029] As a method for allowing lubricating oil to flow from the connection between the first lubrication pipe and the first oil hole, for example, the first lubrication pipe can be loosely fitted to the opening of the first oil hole without clamping a sealing member such as an O-ring, as long as there is a gap (clearance) between the pipe and the first oil hole. However, it is also possible to provide a notch, groove, or through hole for allowing lubricating oil to flow out at a specified flow rate at or near the connection. For the connection between the first lubrication pipe and the first oil hole, for example, a mating is appropriate, but threaded fastening or butt jointing can also be used. For example, an upwardly extending V-shaped or U-shaped oil receiver is provided at the opening of the second oil hole. The connection portion of the first lubrication pipe and the first oil hole is positioned such that at least a portion overlaps with the oil receiver in the vertical direction. However, the opening of the second oil hole may also be positioned at a position that is offset horizontally from the lower position in the vertical direction relative to the connection portion of the first lubrication pipe and the first oil hole. A groove-shaped oil guide is provided on the wall surface of the housing to block the lubricating oil flowing out from the connection portion and guide it to the opening of the second oil hole.

[0030] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in the following embodiments, for ease of explanation, the drawings have been appropriately simplified or modified, and the dimensions and shapes of the various parts are not necessarily drawn correctly.

[0031] Figure 1 This describes a lubrication structure, as an embodiment of the present invention, having a vehicle lubrication system 120 (see reference). Figure 2 The diagram shows the architecture of the power transmission device 12 of a hybrid electric vehicle 10 (hereinafter simply referred to as vehicle 10), which is an unfolded view showing the multiple shafts constituting the power transmission device 12 lying in a common plane. The power transmission device 12 is a transverse type transmission drive axle of an FF vehicle or the like, in which multiple shafts are arranged along the vehicle width direction, and is equipped with a first axis S1 to a fourth axis S4 that are approximately parallel to the vehicle width direction, i.e., approximately horizontal. On the first axis S1, an input shaft 22 connected to the engine 16 via a damping device 18 is provided, and a single pinion type planetary gear unit 24 and a first rotating machine MG1 are arranged concentrically with the first axis S1. The planetary gear unit 24 and the first rotating machine MG1 function as an electric differential unit 26. The input shaft 22 is connected to the planetary gear carrier 24c of the planetary gear unit 24, which is the differential mechanism, and the rotor shaft 28 of the first rotating machine MG1 is connected to the sun gear 24s. An engine output gear Ge is provided on the gear ring 24r. The sun gear 24s and the ring gear 24r mesh with a plurality of pinions 24p that are rotatably mounted on the planetary gear carrier 24c.

[0032] The first rotating unit MG1 is an electric generator that can be selectively used as both an electric motor and a generator. It is equivalent to a rotating unit for differential control. In regenerative control, where it functions as a generator, the rotational speed of the sun gear 24s is continuously controlled, thereby continuously changing the rotational speed of the engine 16 and outputting it from the engine output gear Ge. That is, the electric differential unit 26 can be considered as an electric continuously variable transmission (CVT) capable of continuously changing the gear ratio γ (=engine rotational speed Ne / output rotational speed Nout). The engine rotational speed Ne is the rotational speed of the engine 16, and the output rotational speed Nout is the rotational speed of the engine output gear Ge. Therefore, regardless of the change in the output rotational speed Nout corresponding to the vehicle speed V, the electric differential unit 26 can operate the engine 16 at, for example, a constant optimal fuel consumption operating point, i.e., engine rotational speed Ne and engine torque Te, where fuel consumption is optimal. Furthermore, by setting the torque of the first rotating unit MG1 to 0, the sun gear 24s is allowed to idle, cutting off the output from the engine 16 and preventing the engine 16 from rotating during electric motor operation or inertial driving. Engine 16 is an internal combustion engine such as a gasoline engine or diesel engine that generates power through the combustion of fuel, and is used as a driving force source for travel. The input shaft 22 is inserted into the shaft passing through the first rotating machine MG1 and connected to the I / P pump 56, which is mechanically driven by the engine 16. The I / P pump 56 is a mechanical oil pump that is mechanically driven by the engine 16.

[0033] A secondary shaft 36 is rotatably arranged on the second axis S2. The secondary shaft 36 is equipped with a large reduction gear Gr1 and a small reduction gear Gr2. The large reduction gear Gr1 meshes with the engine output gear Ge. Additionally, the large reduction gear Gr1 meshes with the electric motor output gear Gm arranged on the third axis S3. The electric motor output gear Gm is located on a gear shaft 42, which is connected via a splined joint 46 to the rotor shaft 44 of a second rotating machine MG2, which is concentrically arranged with the third axis S3. The second rotating machine MG2 is an electric generator that can be used as both an electric motor and a generator. It is used as a driving force source for travel by controlling power operation in a manner that functions as an electric motor. This second rotating machine MG2 is equivalent to a traveling rotating machine. The vehicle 10 is a multi-axle series hybrid electric vehicle on a third axis S3, which is different from the first axis S1, where the engine 16 and the electric differential unit 26 are arranged.

[0034] The aforementioned reduction pinion Gr2 meshes with the differential gear ring Gd of the differential device 48 disposed on the fourth axis S4. The driving force from the engine 16 and the second rotating machine MG2 is distributed to the left and right drive shafts 52 via the differential device 48 and transmitted to the left and right drive wheels 54. The fourth axis S4, as... Figure 4 As shown, the first axis S1 to the fourth axis S4 is positioned at the lowest point on the vehicle side. The second axis S2 and the third axis S3 are positioned above the fourth axis S4. The first axis S1 is positioned diagonally above the fourth axis S4, closer to the front of the vehicle. The third axis S3, which is configured with the second rotating machine MG2 or the gear shaft 42, is positioned at the highest point on the vehicle side among the first axis S1 to the fourth axis S4.

[0035] The differential gear ring Gd also meshes with the pump drive gear Gp, and the O / P pump 58 is linked to the differential gear ring Gd, in other words, linked to the drive wheel 54, and is mechanically driven to rotate. That is, the O / P pump 58 is a mechanical oil pump, which is driven to rotate by meshing with the differential gear ring Gd as the output unit, discharging lubricating oil at a discharge volume corresponding to the vehicle speed V, and the discharge volume increases as the vehicle speed V increases. The O / P pump 58 can also be driven to rotate by the pump drive gear Gp meshing with other output units such as the large reduction gear Gr1 or the small reduction gear Gr2 that rotates in conjunction with the differential gear ring Gd.

[0036] The power transmission device 12 is equipped with a transmission drive axle housing 60 (hereinafter simply referred to as housing 60), which is integrally fixed to the engine 16 and supported by the vehicle body via a bracket or the like. The housing 60 is composed of three housing members: a front housing member 62, a middle housing member 64, and a rear cover 66. They are joined together by multiple fastening bolts with mating portions such as flanges at each axial end. The opening of the front housing member 62 toward the engine 16 is integrally fixed to the engine 16, forming a first receiving space 72 for accommodating the shock absorber 18 between the front housing member 62 and the engine 16. The intermediate housing member 64 is integrally equipped with a cylindrical outer cylinder 74 and a partition wall 76. The partition wall 76 extends inward from the outer cylinder 74 and is arranged in a position substantially orthogonal to the first axis S1 to the fourth axis S4. A second receiving space 78 is formed between the front housing member 62 and the partition wall 76 to accommodate the power transmission device 12, such as the electric differential 26, the countershaft 36, the gear shaft 42, and the differential device 48. The front housing member 62 and the partition wall 76 are equipped with support portions that rotatably support the engine output gear Ge, the countershaft 36, the gear shaft 42, the differential device 48, etc., via bearing members such as bearings. In addition, a third receiving space 80 is formed between the rear cover 66 and the partition wall 76 to accommodate the first rotating machine MG1 and the second rotating machine MG2. The rear cover 66 and the partition wall 76 are equipped with support portions that rotatably support the rotor shafts 28 and 44 via bearing members such as bearings. The first receiving space 72 can be referred to as a shock absorption chamber, the second receiving space 78 as a gear chamber, and the third receiving space 80 as an electric motor chamber.

[0037] In the vehicle 10 equipped with such a power transmission device 12, a BEV (Battery Electric Vehicle) driving mode can be adopted, in which the engine 16 is stopped and only the second rotating machine MG2 is used as a driving power source, and a HEV (Hybrid Electric Vehicle) driving mode can be adopted, in which at least the engine 16 is used as a driving power source. In the HEV driving mode, the power operation of the second rotating machine MG2 is controlled as needed, thereby allowing both the engine 16 and the second rotating machine MG2 to be used as driving power sources for driving.

[0038] Figure 2 This is a schematic diagram of the vehicle lubrication system 120 equipped on vehicle 10. Additionally, Figure 3 This is a perspective view specifically illustrating the power transmission device 12 of the vehicle lubrication system 120, and the housing 60 is omitted in the representation. Figure 4This diagram illustrates the state in which the I / P oil pump 160 and O / P oil pump 166, constituting the oil passage of the vehicle lubrication system 120, are installed in the housing 60. It is a front view of the partition wall 76 of the intermediate housing member 64, viewed from the second receiving space 78 side. The vehicle lubrication system 120 is equipped with the aforementioned I / P pump 56 and O / P pump 58 as suction devices, via... Figure 2 The I / P oil passage 122, indicated by a solid line, or the O / P oil passage 126, indicated by a dashed line, is responsible for lubricating the various parts of the rotating machines MG1 and MG2, as well as the power transmission device 12. The I / P pump 56 and the O / P pump 58 draw oil from the oil reservoir 150 (see reference 126) located at the bottom of the housing 60 via filters 130 and 132, respectively. Figure 4 The pump 56 draws in lubricating oil and outputs the lubricating oil 152 to the I / P oil passage 122 or the O / P oil passage 126. In this embodiment, filters 130 and 132 are provided respectively; however, the I / P pump 56 and the O / P pump 58 may also be configured to draw in lubricating oil 152 from a common filter.

[0039] Since the O / P pump 58 is connected to the differential 48 and is mechanically driven to rotate, it is also driven to rotate in the BEV driving mode where the engine 16 stops rotating. This allows it to draw in lubricating oil 152 at a volume corresponding to the vehicle speed V and supply lubricating oil 152 to various parts. Because the engine 16, which drives the I / P pump 56 to rotate, can also be driven when the vehicle is stationary, it can draw in lubricating oil 152 at a volume independent of the vehicle speed V and supply it to lubrication points, including when the vehicle is stationary. However, in the BEV driving mode, the operation of the I / P pump 56 also stops as the engine 16 stops rotating. The lubricating oil 152 discharged from the I / P pump 56 is mainly used for cooling the rotating machines MG1 and MG2. In contrast, the lubricating oil 152 discharged from the O / P pump 58 is used for lubrication of the gear meshing parts and bearing components of various parts of the power transmission device 12. In this embodiment, a large pump with a larger discharge capacity than the O / P pump 58 is used as the I / P pump 56 so that the cooling performance of the rotating machines MG1 and MG2 can be stably obtained.

[0040] I / P oil passage 122 is connected to the discharge side of I / P pump 56, supplying lubricating oil 152 to rotating machines MG1 and MG2. Figure 2 And other embodiments Figure 8In the diagram, downward arrows relative to rotating machines MG1 and MG2 indicate that lubricating oil 152 flows down from above rotating machines MG1 and MG2 to cool the stator, etc. Conversely, upward arrows relative to rotating machines MG1 and MG2 indicate that lubricating oil 152 is supplied from the center side of rotating machines MG1 and MG2 to cool and lubricate the rotor or bearings, etc., and the lubricating oil 152 is discharged from oil holes located at the shaft centers of input shaft 22, rotor shafts 28 and 44, etc. In this I / P oil circuit 122, an overflow valve (safety valve) 134 is connected at an overflow position 122r, which is an intermediate position before reaching rotating machines MG1 and MG2, to prevent excessive oil pressure within the I / P oil circuit 122. Furthermore, an oil cooler 138 is provided on the side of rotating machines MG1 and MG2 closer to the overflow position 122r where the overflow valve 134 is connected, and the lubricating oil 152 cooled by the oil cooler 138 is supplied to rotating machines MG1 and MG2. In this embodiment, the oil cooler 138 is a water-cooled cooler that cools the lubricating oil 152 by water cooling. It is disposed on the outside of the housing 60. The lubricating oil 152 is cooled by heat exchange with the cooling medium in the cooling medium circulation loop (not shown in the figure). The cooling medium circulation loop circulates the cooling medium such as coolant and is equipped with a radiator or a cooling medium pump that uses the external atmosphere to cool the cooling medium.

[0041] The aforementioned I / P oil passage 122 supplies lubricating oil 152 to designated lubrication points via oil holes provided on the side wall of the housing 60 or other independent piping separate from the housing 60. In this embodiment, as independent piping separate from the housing 60, an I / P oil pipe 160 disposed in the second receiving space 78, an MG1 oil pipe 162 disposed in the third receiving space 80, and an MG2 oil pipe 164 are provided. These oil pipes 160, 162, and 164 are all resin pipes. The I / P oil pipe 160 is disposed along the partition wall 76 of the intermediate housing member 64 and is fixed to the partition wall 76 at multiple locations. The I / P oil pipe 160 is provided with three connecting portions 160a to 160c, through which lubricating oil 152 is supplied from the oil cooler 138. Connecting portions 160b and 160c are respectively connected to communicating oil holes 76a and 76b (see reference) provided in the partition wall 76. Figure 2The lubricating oil 152 is supplied to the MG1 oil pipe 162 and MG2 oil pipe 164 within the third receiving space 80 via the connecting oil holes 76a and 76b. The MG1 oil pipe 162 and MG2 oil pipe 164 are straight pipes arranged approximately parallel to the axes S1 and S3 above the first rotating machine MG1 and the second rotating machine MG2, respectively. One end of each pipe is connected to the connecting oil holes 76a and 76b of the partition wall 76 to supply lubricating oil 152. Furthermore, multiple downward-facing discharge holes are provided at intervals along the length of these MG1 oil pipes 162 and MG2 oil pipes 164, through which the lubricating oil 152 supplied from the I / P oil pipe 160 is discharged downwards and distributed on the outer peripheral surfaces of the stators of the first rotating machine MG1 and the second rotating machine MG2 for cooling.

[0042] The I / P oil passage 122 is equipped with a branch oil passage 124 that branches off at a branch point 122p between the overflow position 122r and the I / P pump 56. Lubricating oil 152 is supplied to the first rotating machine MG1 or the planetary gear unit 24 of the electric differential unit 26 via this branch oil passage 124. A throttling orifice 140 is provided in the branch oil passage 124 to limit the amount of lubricating oil 152 flowing into the branch oil passage 124 from the branch point 122p, properly ensuring the amount of lubricating oil supplied to the oil cooler 138. The branch oil passage 124 supplies lubricating oil 152, for example, through oil holes provided in the rotor shaft 28, input shaft 22, etc., of the first rotating machine MG1, to cool and lubricate the rotor and bearings of the first rotating machine MG1, or to lubricate the gear meshing parts and bearings of the planetary gear unit 24.

[0043] The O / P oil passage 126 is connected to the discharge side of the O / P pump 58, supplying lubricating oil 152 to the reduction section 128, which is equipped with a large reduction gear Gr1, a small reduction gear Gr2, an electric motor output gear Gm, etc., and the differential device 48. This O / P oil passage 126 supplies lubricating oil 152, for example, via a pipe separately and independently provided from the housing 60, or via an oil hole provided in the housing 60. In this embodiment, the O / P oil passage 126 is mainly composed of a resin O / P oil pipe 166, which is separately and independently provided from the housing 60. The O / P oil pipe 166 is disposed within the second receiving space 78, fixed to the partition wall 76 at multiple locations, and connected to the O / P pump 58 at its lower end, from which lubricating oil 152 is supplied. The upper end of the O / P oil pipe 166 extends to the position above the large reduction gear Gr1, the small reduction gear Gr2, and the motor output gear Gm. At this position, a plurality of protruding nozzles 166a are provided, protruding in a direction parallel to the second axis S2 or the third axis S3. Lubricating oil 152 is discharged downward or horizontally from these protruding nozzles 166a and distributed to the large reduction gear Gr1, the small reduction gear Gr2, the motor output gear Gm, etc., to lubricate the meshing parts of these gears, bearings, etc.

[0044] Furthermore, in the aforementioned O / P oil pipe 166, a crank portion 166b, bent into a crank shape parallel to the fourth axis S4, is provided in the middle section. The crank portion 166b is located above the differential device 48 or the differential gear ring Gd, and a discharge hole is provided in the crank portion 166b to discharge lubricating oil 152, which is used to lubricate the differential gear ring Gd, the differential device 48, bearings, etc. A portion of the differential device 48 is immersed in the oil reservoir 150 at the lower part of the housing 60 and lubricated by an oil bath. As the differential device 48 rotates, the lubricating oil 152 is carried up, thereby distributing the lubricating oil 152 to various parts of the power transmission device 12 for lubrication.

[0045] Figure 5 It is an enlarged representation Figure 4 Part of the shell 60, namely Figure 4 The perspective view of the upper left portion of the partition wall 76 shows that the connection portion 160c of the I / P oil pipe 160 is connected to the vicinity of the communicating oil hole 76b of the partition wall 76. Additionally, Figure 6 It is equivalent to Figure 5The sectional view of the power transmission device 12 in the VI-VI direction illustrates the bearing structure of the rotor shaft 44 and gear shaft 42 arranged on the third axis S3, and the connection structure of the I / P oil pipe 160 connected above the third axis S3. The end of the gear shaft 42 on the second rotating MG2 side has a smaller diameter than the rotor shaft 44 and is embedded in the cylinder of the rotor shaft 44, and is connected via a spline fitting 46 for power transmission. The rotor shaft 44 is connected via a pair of first bearings 92a, 92b (see reference 1). Figure 1 The rotor shaft 42 is rotatably supported by the housing 60 around the third axis S3. First bearings 92a and 92b are axially positioned on both sides of the rotor of the second rotating machine MG2. The gear shaft 42 is rotatably supported by the housing 60 around the third axis S3 via a pair of second bearings 96a and 96b. The second bearings 96a and 96b are axially positioned on both sides of the motor output gear Gm. Both the first bearing 92a and the second bearing 96a are ball bearings, configured and held inside the cylindrical first bearing holder 98 and second bearing holder 100, which are respectively provided as support portions on the spacer walls 76 of the intermediate housing member 64.

[0046] Here, in order to lubricate the first bearing 92a and the second bearing 96a, an oil inlet hole 102 is provided in the second bearing holding part 100 to guide the lubricating oil 152 supplied from the O / P oil pipe 166 into the interior of the second bearing holding part 100. The oil inlet hole 102 is provided in a portion above the third axis S3 such that it passes through the cylindrical second bearing holding part 100 from the outer peripheral side to the inner peripheral side, and it opens in the portion between the first bearing 92a and the second bearing 96a as it tends inward from the outer opening on the outer peripheral side, i.e., downward, and from the direction orthogonal to the third axis S3 toward the first bearing holding part 98. The outer opening of the oil inlet hole 102 opens obliquely upwards, and around this opening, an oil receiver 104 with a U-shaped or V-shaped cross-section, whose width increases upwards, is provided. Lubricating oil 152 discharged downwards from the protruding nozzle portion 166a of the O / P oil pipe 166 is blocked by the oil receiver 104 and guided into the oil inlet hole 102, where it is supplied to the portion between the first bearing 92a and the second bearing 96a. That is, one of the plurality of protruding nozzle portions 166a provided in the O / P oil pipe 166, such as... Figure 6 As shown, the lubricating oil 152 discharged from the protruding nozzle portion 166a is positioned directly above the oil receiver 104, and flows into the oil inlet hole 102 via the oil receiver 104. The front end side of the oil receiver 104 ( Figure 6The opening on the right side of the partition wall 76 can be fitted with a sidewall to restrict the outflow of lubricating oil 152, as needed. The oil receiver 104 is integrally provided with the partition wall 76, but it is also possible to separately construct the oil receiver 104 from the intermediate housing member 64 and install it thereafter.

[0047] On the other hand, a connecting oil hole 76b is provided directly above the oil receiver 104 in the vertical direction for connecting the connection portion 160c of the I / P oil pipe 160. The connecting oil hole 76b connects the I / P oil pipe 160, which is disposed in the second receiving space 78, and the MG2 oil pipe 164, which is disposed in the third receiving space 80, and is arranged approximately parallel to the third axis S3. Countersunk holes 106 and 108 are respectively provided at the openings on both sides of the connecting oil hole 76b, and the connection portion 160c of the I / P oil pipe 160 and the MG2 oil pipe 164 are respectively fitted into the countersunk holes 106 and 108. The MG2 oil pipe 164, for example, abuts against the bottom (stepped portion) of the countersunk hole 108 in an oil-sealed manner to prevent oil leakage between it and the connecting oil hole 76b. Sealing components such as O-rings can be used as needed. On the other hand, the connecting portion 160c is loosely fitted to the countersunk hole 106 with a predetermined gap from the connecting portion 170 of the connecting hole 76b, so that even at extremely low temperatures (e.g., below -20°C) where the viscosity of the lubricating oil 152 becomes high, a predetermined amount of lubricating oil 152 will leak out and flow down from the connecting portion 170. Specifically, the fitting is performed without using sealing members such as O-rings, so that there is a predetermined gap between it and the bottom (stepped portion) of the countersunk hole 106, and a predetermined clearance between it and the inner circumferential surface of the countersunk hole 106. Furthermore, at least a portion of the lubricating oil 152 flowing out from the connecting portion 170 flows downward along the spacer wall 76, whereby it is blocked by the oil receiver 104 and flows into the oil inlet hole 102 for lubrication of the first bearing 92a and the second bearing 96a. The oil receiver 104 functions as an oil guide that blocks the lubricating oil 152 flowing out from the connecting portion 170 and guides it into the oil inlet hole 102. In the connecting part 160c of the connecting part 170, a discharge hole or the like may be provided as needed so that even at extremely low temperatures, a specified amount of lubricating oil 152 will flow out and be supplied to the oil inlet hole 102.

[0048] In this embodiment, the I / P oil pipe 160 corresponds to the first lubrication pipe, the connecting oil hole 76b corresponds to the first oil hole, and the second rotating machine MG2, cooled by lubricating oil discharged from the MG2 oil pipe 164, corresponds to the rotating machine supplied with lubricating oil 152 from the first lubrication pipe via the first oil hole. Additionally, the O / P oil pipe 166 corresponds to the second lubrication pipe, the oil inlet hole 102 corresponds to the second oil hole, and the first bearing 92a and the second bearing 96a correspond to bearing components lubricated by the lubricating oil 152 supplied from the second lubrication pipe. Furthermore, the housing 60, having a second receiving space 78 containing the I / P oil pipe 160 and the O / P oil pipe 166, corresponds to the housing containing the first and second lubrication pipes. That is, the bearings 92a and 96a located on the third axis S3, which is the uppermost side of the vehicle among the first axis S1 to the fourth axis S4, are difficult to be adequately lubricated by the lubricating oil 152 being carried up by the rotation of the differential device 48. Furthermore, since they are far from the O / P pump 58, there is a possibility that the supply of lubricating oil 152 supplied only from the O / P oil pipe 166 may be insufficient and burn out if the viscosity of the lubricating oil 152 increases due to low temperature. Therefore, lubricating oil 152 may also be supplied from the I / P oil pipe 160.

[0049] Thus, according to the lubrication structure of the vehicle 10 of this embodiment, namely the vehicle lubrication system 120, in order to supply the lubricating oil 152 discharged from the O / P oil pipe 166 to the first bearing 92a and the second bearing 96a, the connection portion 170 of the I / P oil pipe 160 supplying lubricating oil 152 to the oil inlet hole 76b is positioned above the opening of the oil inlet hole 102 provided in the second bearing holding portion 100. At least a portion of the lubricating oil 152 flowing out from the connection portion 170 flows into the oil inlet hole 102. Therefore, at extremely low temperatures where the viscosity of the lubricating oil 152 is high, the insufficient supply of lubricating oil 152 to the first bearing 92a and the second bearing 96a is suppressed.

[0050] Furthermore, since lubricating oil flows out from the connection portion 170 between the I / P oil pipe 160 and the connecting oil hole 76b, and the connecting oil hole 76b is positioned above the opening of the oil inlet hole 102, it can be easily implemented without significant design changes. Moreover, compared to the case where the O / P pump 58 is enlarged in order to supply a sufficient amount of lubricating oil 152 to the first bearing 92a and the second bearing 96a from the O / P oil pipe 166 even at extremely low temperatures, it can be constructed at a low cost.

[0051] Furthermore, since the connection portion 160c is loosely fitted to the countersunk hole 106 of the oil hole 76b with a specified gap without the use of sealing components such as O-rings, the lubricating oil 152 can leak out and flow down from the connection portion 170 of the connection portion 160c of the I / P oil pipe 160 and the oil hole 76b, it can be implemented simply and inexpensively.

[0052] Furthermore, since an oil receiver 104 is provided at the opening of the oil inlet hole 102, and the connecting portion 170 is positioned directly above the oil receiver 104 in the vertical direction, at least a portion of the lubricating oil 152 flowing down from the connecting portion 170 is blocked by the oil receiver 104 and reliably flows into the oil inlet hole 102, thus properly suppressing the insufficient supply of lubricating oil 152 to the first bearing 92a and the second bearing 96a.

[0053] Furthermore, since it is equipped with an I / P pump 56 that is mechanically driven by the engine 16 and an O / P pump 58 that is mechanically driven by the differential device 48 connected to the output unit, lubricating oil 152 is supplied from the I / P pump 56 to the I / P oil line 160 and from the O / P pump 58 to the O / P oil line 166. Therefore, at low vehicle speeds, the discharge volume of the O / P pump 58 is reduced, and the amount of lubricating oil supplied from the O / P oil line 166 to the first bearing 92a and the second bearing 96a is reduced. However, by a portion of the lubricating oil 152 supplied from the I / P pump 56 to the I / P oil line 160 flowing out from the connection portion 170 with the communicating oil hole 76b and flowing into the oil inlet hole 102, the insufficient supply of lubricating oil 152 to the first bearing 92a and the second bearing 96a at low vehicle speeds is suppressed.

[0054] Furthermore, since the discharge capacity of the I / P pump 56 is larger than that of the O / P pump 58, and the viscosity of the lubricating oil 152 has a smaller impact on the I / P pump 56 with its larger discharge capacity, even at extremely low temperatures where the viscosity increases, a sufficient amount of lubricating oil 152 can be supplied to the second rotating machine MG2 for proper cooling. Moreover, by having a portion of the lubricating oil 152 flow into the oil inlet hole 102 and be supplied to the first bearing 92a and the second bearing 96a, the effect of suppressing insufficient supply of lubricating oil 152 to the first bearing 92a and the second bearing 96a can be properly achieved without enlarging the O / P pump 58.

[0055] Next, other embodiments of the present invention will be described. Furthermore, in the following embodiments, the same reference numerals are used for parts that are substantially common to the embodiments described above, and detailed descriptions thereof are omitted.

[0056] Figure 7 It corresponds to Figure 5The figure is a perspective view of the upper left portion of the spacer wall 76 of the oil inlet hole 102, which is provided with a connecting oil hole 76b connected to the connection portion 160c of the I / P oil pipe 160 and for supplying lubricating oil 152 to the first bearing 92a and the second bearing 96a. In this embodiment, the position of the outer opening of the oil inlet hole 102 is different from that in the previous embodiment, and is offset from directly below the connecting oil hole 76b connected to the connection portion 160c. Furthermore, directly below the connecting oil hole 76b, there is an inclined groove-shaped oil guide 172 that guides the lubricating oil 152 flowing down from the connection portion 170 of the connecting oil hole 76b and the connection portion 160c to the oil inlet hole 102. In this case, the protruding nozzle portion 166a of the O / P oil pipe 166 is preferably directly above the oil inlet hole 102, but it can be anywhere above the oil guide 172, as long as the flowing lubricating oil 152 is blocked. Multiple oil inlet holes 102 can also be provided. In this embodiment, the same effect as the previously described embodiment is achieved.

[0057] Figure 8 It corresponds to Figure 2 The diagram shows the vehicle lubrication system 200, indicated by dashed lines. It includes a second O / P oil passage 202 connecting the O / P pump 58 to the I / P oil passage 122. A portion of the lubricating oil 152 discharged from the O / P pump 58 is supplied to the I / P oil passage 122. The second O / P oil passage 202 is constructed, for example, by piping such as resin tubing; however, it may also be constructed by oil holes provided on the sidewalls of the housing 60. The second O / P oil passage 202 is provided independently of the O / P oil passage 126, and a throttling orifice 142 is provided in the O / P oil passage 126 to limit the amount of lubricating oil flowing into it, thus appropriately ensuring the amount of lubricating oil supplied from the second O / P oil passage 202 to the I / P oil passage 122.

[0058] The O / P second oil passage 202 is connected to the confluence point 122j located between the branch point 122p and the overflow position 122r of the I / P oil passage 122. A check valve 204 is provided near the confluence point 122j, allowing lubricating oil 152 to flow towards the confluence point 122j but preventing flow in the opposite direction. A check valve 206 is also provided near the confluence point 122j of the I / P oil passage 122, allowing lubricating oil 152 to flow towards the confluence point 122j but preventing flow in the opposite direction. Thus, the high-pressure side lubricating oil 152 in both the I / P oil passage 122 and the O / P second oil passage 202 is supplied from the confluence point 122j to the rotating machines MG1 and MG2 via the oil cooler 138. That is, in BEV driving mode, when the engine 16 stops rotating and the I / P pump 56 stops operating, a portion of the lubricating oil 152 discharged from the O / P pump 58 is supplied to the rotating machines MG1 and MG2 via the O / P second oil passage 202 and the I / P oil passage 122. Therefore, the second rotating machine MG2, which serves as a driving power source, is properly cooled. In other words, the driving time in BEV driving mode, where the engine 16 stops rotating, can be extended to improve fuel efficiency, making it well-suited for plug-in hybrid electric vehicles capable of external charging. The aforementioned check valves 204 and 206 can, for example, be assembled together with the previously described overflow valve 134 into a common valve body 208.

[0059] In this embodiment, since a throttling orifice 142 is provided in the O / P oil passage 126, the risk of insufficient lubricating oil supply to the first bearing 92a and the second bearing 96a increases when the viscosity of the lubricating oil 152 is high at extremely low temperatures. Conversely, since the lubricating oil 152 flows out from the connection portion 170 between the I / P oil pipe 160 of the I / P oil passage 122 supplying lubricating oil 152 to the second rotating machine MG2 and the connecting oil hole 76b, flows into the oil inlet hole 102 and is supplied to the first bearing 92a and the second bearing 96a, the effect of suppressing insufficient supply of lubricating oil 152 to the first bearing 92a and the second bearing 96a can be significantly achieved without enlarging the O / P pump 58.

[0060] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, these are merely one implementation method, and the present invention can be implemented in various ways with modifications and improvements based on the knowledge of those skilled in the art.

Claims

1. A lubrication structure for a vehicle, characterized in that, include: A first lubrication pipe supplies lubricating oil to the rotating machine housed within the housing; A second lubrication pipe supplies lubricating oil to the bearing components disposed in the housing; as well as One or more oil pumps supply lubricating oil to the first lubrication piping and the second lubrication piping. The lubrication structure of the vehicle is equipped with a first oil hole and a second oil hole. In order to supply lubricating oil to the rotating machine, the housing is provided with the first oil hole, and the first lubrication pipe is connected to the first oil hole; To supply lubricating oil to the bearing component, a second oil hole is provided in the housing, and lubricating oil flows into the second oil hole from the second lubrication pipe. To allow at least a portion of the lubricating oil flowing from the connection between the first lubrication pipe and the first oil hole to flow into the second oil hole, the connection is positioned above the opening of the second oil hole. The first lubrication pipe is loosely fitted with the first oil hole with a specified gap at the connection portion without a sealing member, so that even at extremely low temperatures where the lubricating oil has a high viscosity, the lubricating oil will leak and flow down from the connection portion. At the opening of the second oil hole, there is an upwardly extending V-shaped or U-shaped oil receiver, and the connecting portion is positioned at least partially overlapping the oil receiver in the vertical direction.

2. The lubrication structure of the vehicle as described in claim 1, characterized in that, The vehicle is a hybrid electric vehicle equipped with: an engine; and a power transmission device that transmits the driving force from the engine to the drive wheels via an output section. And a rotating mechanism for travel, which is connected to the output unit. The power transmission device and the rotating mechanism for travel are housed within the housing. The rotating mechanism is the rotating machine itself. A bearing member is provided to support a defined rotating component of either the power transmission device or the rotating mechanism for travel. Furthermore, among the one or more oil pumps, an I / P pump that is mechanically driven by the engine to discharge lubricating oil, and an O / P pump connected to the output section and mechanically driven to discharge lubricating oil, are provided. Lubricating oil is supplied from the I / P pump to the first lubrication pipe for cooling the stator of the traveling rotary machine, and lubricating oil is supplied from the O / P pump to the second lubrication pipe for lubricating the bearing components.

3. The lubrication structure of the vehicle as described in claim 2, characterized in that, The discharge capacity of the I / P pump is greater than that of the O / P pump.

4. The lubrication structure of the vehicle as described in claim 1, characterized in that, The opening of the second oil hole is offset from directly below the connecting portion, and an inclined groove-shaped oil guide is provided directly below the connecting portion, which guides at least a portion of the lubricating oil flowing out from the connecting portion into the second oil hole.

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