Power transmission device

Abstract

The utility model relates to a power transmission device which can supply engine oil to the interior of a rotor shaft and supply the engine oil to a motor chamber from the interior of the rotor shaft. A power transmission device is provided with: a housing that accommodates a motor and a gear mechanism; a rotating shaft extending inside the hollow rotor shaft; and an in-shaft space formed between the rotor shaft and the rotating shaft, provided with: a helical structure which is provided on at least one of the inner peripheral portion of the rotor shaft and the outer peripheral portion of the rotating shaft on one end side of the rotor shaft, and which supplies oil to the in-shaft space by pressing oil in the axial direction by the relative rotation of the rotor shaft and the rotating shaft; and a through-hole that passes through the rotor shaft in the radial direction, connects the in-shaft space and an out-shaft space in which the rotor is disposed in a motor chamber in which the motor is housed, and causes oil supplied to the in-shaft space to flow from the in-shaft space to the out-shaft space by means of a helical structure that extends in the axial direction to a position in which the through-hole is provided.

Description

Technical Field

[0001] This utility model relates to a power transmission device. Background Technology

[0002] Patent Document 1 discloses the following: Inside the housing housing the motor and gear mechanism, a groove is provided between a hollow rotor shaft and a rotating shaft disposed inside the rotor shaft. Through the relative rotation of the rotor shaft and the rotating shaft, the groove presses oil axially. In the structure described in Patent Document 1, the oil supplied to one end of the rotor shaft is axially pressed by the groove into the internal space of the rotor shaft towards the other end, thereby enabling the supply of oil to the spline engagement portion of the gear at the other end of the rotor shaft.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-57758 Utility Model Content

[0006] The problem to be solved by the utility model

[0007] However, in the structure described in Patent Document 1, the oil that is pressed into the inside of the rotor shaft from one end of the rotor shaft by the groove is oil that returns to the gear chamber from the other end of the rotor shaft via the inside of the rotor shaft, rather than oil supplied to the motor chamber from the inside of the rotor shaft.

[0008] This invention is made in view of the above circumstances, and its purpose is to provide a power transmission device that can supply oil to the interior of the rotor shaft and supply oil from the interior of the rotor shaft to the motor chamber.

[0009] Methods for solving problems

[0010] This utility model is a power transmission device, equipped with: a housing housing a motor and a gear mechanism; a rotating shaft extending inside a hollow rotor shaft that rotates integrally with the rotor of the motor, outputting power transmitted from the gear mechanism; and an inner shaft space formed between the rotor shaft and the rotating shaft. The power transmission device is characterized by: a helical structure disposed at at least one of the inner circumference of the rotor shaft and the outer circumference of the rotating shaft at one end of the rotor shaft, which, through relative rotation of the rotor shaft and the rotating shaft, axially presses oil and supplies the oil to the inner shaft space; and a through hole radially penetrating the rotor shaft, connecting the inner shaft space to the outer shaft space where the rotor is disposed within a motor housing housing the motor, and allowing the oil supplied to the inner shaft space by the helical structure to flow from the inner shaft space to the outer shaft space. The helical structure extends axially to the position where the through hole is provided.

[0011] Effects of the utility model

[0012] In this invention, oil can be supplied to the inside of the rotor shaft, and oil can also be supplied from the inside of the rotor shaft to the motor chamber. Attached Figure Description

[0013] Figure 1 This is a schematic diagram illustrating the power transmission device in the embodiment.

[0014] Figure 2 This is a diagram used to illustrate the structure of one end of the rotor shaft.

[0015] Figure 3 This diagram illustrates the use of a spiral structure to pressurize and deliver engine oil axially.

[0016] Figure 4 This is a diagram used to illustrate the structure of one end of the rotor shaft in the first variation.

[0017] Figure 5 This is a diagram used to illustrate the structure of one end of the rotor shaft in the second variation.

[0018] Figure 6 This is a diagram used to illustrate the structure of one end of the rotor shaft in the third variation.

[0019] Figure 7 This diagram illustrates the situation where the rotor shaft reverses in the third variation.

[0020] Explanation of reference numerals in the attached drawings: 1 Power transmission device, 2 Motor, 4 Intermediate shaft, 5 Drive shaft, 10 Housing, 11 Motor chamber, 12 Gear chamber, 14 Internal space of the shaft, 15 External space of the shaft, 21 Rotor, 23 Rotor shaft, 23a Through hole, 40 Helical structure, A: Forward rotation, B: Reverse rotation. Detailed Implementation

[0021] The power transmission device in the embodiments of this utility model will now be described in detail. However, this utility model is not limited to the embodiments described below.

[0022] Figure 1 This diagram schematically illustrates the power transmission device in the embodiment. The power transmission device 1 is composed of a single-shaft e-Axle type electric drive system. The power transmission device 1 is equipped with a motor 2, a PCU 3, a gear mechanism, and an intermediate shaft 4. Furthermore, in... Figure 1 The diagram of the gear mechanism is omitted in the above.

[0023] The power transmission unit 1 is a drive unit integrating the motor 2, PCU3, and gear mechanism, and is mounted in an electric vehicle. The power transmission unit 1 inputs power from the motor 2 to the gear mechanism, and then transmits the power to the intermediate shaft 4 and drive shaft 5 via the gear mechanism. The gear mechanism includes a planetary gear mechanism and a differential mechanism. The power input from the motor 2 to the planetary gear mechanism is transmitted to the differential mechanism via the planetary gear mechanism. The differential mechanism is connected to the left and right drive shafts 5. The intermediate shaft 4 is a rotating shaft connecting the differential mechanism to one drive shaft 5. Power is transmitted to one drive shaft 5 via the intermediate shaft 4, and power is directly transmitted from the differential mechanism to the other drive shaft 5. The power transmitted to the drive shafts 5 is then transmitted to the wheels.

[0024] In the power transmission device 1, a motor 2, a PCU 3, a gear mechanism, and an intermediate shaft 4 are housed inside a housing 10. The housing 10 forms a motor chamber 11 housing the motor 2, a gear chamber 12 housing the gear mechanism, and a PCU chamber housing the PCU 3. The PCU chamber is located above the motor chamber 11 and the gear chamber 12. An oil reservoir 13 is provided at the lower part of the housing 10. Oil contained inside the housing 10 is stored in the oil reservoir 13. The oil is the refrigerant used to cool the motor 2 and the PCU 3. The oil stored in the oil reservoir 13 is supplied to the motor 2 and the PCU 3 by an oil pump 6. The oil pump 6 discharges the oil drawn from the oil reservoir 13 through an oil filter and pressurizes the oil into the housing oil passages and the like provided in the housing 10. Inside the housing 10, the oil supplied to the PCU 3 cools the PCU 3 at the PCU chamber, and flows from the PCU chamber into the lower motor chamber 11 to cool the motor 2. The oil that cooled the motor 2 returned to the oil reservoir 13 by gravity.

[0025] Motor 2 is equipped with a rotor 21, a stator 22, and a rotor shaft 23. The rotor 21 and rotor shaft 23 rotate integrally. The stator 22 includes coils 22a wound around a stator core. The stator 22 is fixed to the housing 10. The rotor shaft 23 is a hollow rotating shaft. The rotor shaft 23 is rotatably supported relative to the housing 10 by bearings mounted at both ends. The rotor shaft 23 is splinedly engaged with the sun gear 31 of the planetary gear mechanism. An intermediate shaft 4 is disposed inside the rotor shaft 23.

[0026] The intermediate shaft 4 extends inside the rotor shaft 23 and is a rotating shaft for outputting power transmitted from the gear mechanism. The intermediate shaft 4 and the rotor shaft 23 rotate relative to each other on the same central axis of rotation. One end of the intermediate shaft 4 is connected to the drive shaft 5. The end of the drive shaft 5 is fitted into the inner circumference of the intermediate shaft 4 and disposed inside the rotor shaft 23. Inside the rotor shaft 23, the intermediate shaft 4 and the drive shaft 5 extend axially. The power transmission device 1 has an internal space 14 formed between the rotor shaft 23 and the intermediate shaft 4.

[0027] like Figure 2 As shown, the power transmission device 1 has a helical structure 40 disposed on the outer periphery of the intermediate shaft 4, and a through hole 23a that radially penetrates the rotor shaft 23. On the intermediate shaft 4, the helical structure 40 is disposed on the outer periphery at one end of the rotor shaft 23. The helical structure 40 is composed of grooves or protrusions. The helical structure 40 is composed of helical grooves or helical protrusions. Figure 3 As shown, the helical structure 40 is a structure that pressurizes and supplies oil axially to the internal space 14 by the relative rotation of the rotor shaft 23 and the intermediate shaft 4. The helical structure 40 is effective for feeding oil from outside the shaft to the internal space 14. The helical structure 40 extends axially to a position where a through hole 23a is provided. In the axial direction, the helical structure 40 is formed to include the range from one end of the rotor shaft 23 to the through hole 23a of the rotor shaft 23.

[0028] The through hole 23a connects the internal space 14 of the shaft and the external space 15, where the motor 21 is located, within the motor chamber 11. For example... Figure 3 As shown, the through hole 23a allows the oil supplied to the inner shaft space 14 by the spiral structure 40 to flow from the inner shaft space 14 to the outer shaft space 15. When the rotor shaft 23 and the intermediate shaft 4 rotate, the oil in the inner shaft space 14 flows out radially outward from the through hole 23a due to centrifugal force.

[0029] like Figure 2As shown, a rotor oil passage 21a is provided in the rotor 21, allowing oil to flow axially within the rotor 21. A guide member 24 is installed at one end of the rotor 21, guiding the oil flowing radially outward from the through hole 23a to the rotor oil passage 21a. The guide member 24 is formed to include a portion radially opposite to the opening of the through hole 23a and a portion axially opposite to the opening of the rotor oil passage 21a. The guide member 24 rotates integrally with the rotor 21 and the rotor shaft 23. In the power transmission device 1, oil supplied to the shaft inner space 14 by the helical structure 40 is supplied from the shaft inner space 14 to the shaft outer space 15, thereby supplying the oil to the rotor oil passage 21a. The oil flowing axially in the rotor oil passage 21a can be used to cool the interior of the rotor 21, improving the cooling performance of the rotor 21.

[0030] As described above, according to the embodiment, without increasing the size of the power transmission device 1 with a single-shaft structure, it is possible to supply oil to the shaft center of the rotor shaft 23, and to supply oil from the shaft inner space 14 to the shaft outer space 15 of the motor chamber 11.

[0031] Furthermore, in the power transmission device 1 of the embodiment, the structure for supplying oil to the shaft space 14 is described only on the intermediate shaft 4; however, the present invention is not limited to this. The helical structure can be provided on at least one of the rotor shaft 23 and the intermediate shaft 4. A modified example of the power transmission device 1, such as... Figures 4 to 7 As shown, it can be configured in various ways. The first variation has a helical structure only on the rotor shaft 23. The second variation has helical structures on both the intermediate shaft 4 and the rotor shaft 23. The third variation has a structure in which the directions of the helical structures on the intermediate shaft 4 and the rotor shaft 23 are reversed.

[0032] like Figure 4 As shown, the power transmission device 1 of the first modified example has a helical structure 50 provided on the inner circumference of the rotor shaft 23. The helical structure 50 is provided on the inner circumference of one end of the rotor shaft 23. The helical structure 50 is formed by grooves or protrusions. The helical structure 50 is a structure that presses oil axially and supplies oil to the shaft interior space 14 by the relative rotation of the rotor shaft 23 and the intermediate shaft 4. The helical structure 50 provided on the inner circumference of the rotor shaft 23 is effective in further axially feeding oil that, although it has entered the shaft interior space 14, has adhered to the inner wall of the rotor shaft 23 due to centrifugal force, into the shaft interior space 23, or in preventing oil from leaking axially outwards from the shaft interior space.

[0033] like Figure 5As shown, the power transmission device 1 of the second modification has a helical structure 40 provided on the outer periphery of the intermediate shaft 4 and a helical structure 50 provided on the inner periphery of the rotor shaft 23. In the second modification, helical structures are provided on both the rotor shaft 23 and the intermediate shaft 4 at one end of the rotor shaft 23.

[0034] like Figure 6 As shown, in the power transmission device 1 of the third modification, the spiral structures 40 of the intermediate shaft 4 and 50 of the rotor shaft 23 are configured with opposite directions. In the structure of the second modification, although it supplies oil to the shaft interior space 14 when the motor 2 rotates in the forward direction, it moves in the direction of discharging oil out of the shaft when the motor 2 rotates in the reverse direction. In contrast, in the third modification, as... Figure 6 , Figure 7 As shown, it can handle both clockwise and counterclockwise rotation.

Claims

1. A power transmission device, equipped with: A housing that houses the motor and gear mechanism; A rotating shaft, extending inside a hollow rotor shaft that rotates integrally with the rotor of the motor, outputs power transmitted from the gear mechanism; and The space within the shaft is formed between the rotor shaft and the rotating shaft. characterized in that The power transmission device is equipped with: A helical structure, wherein the helical structure is disposed at least on one end of the rotor shaft, on the inner circumference of the rotor shaft and the outer circumference of the rotating shaft, wherein the rotor shaft rotates relative to the rotating shaft to pressurize and supply oil axially to the space within the shaft; and A through-hole, which radially penetrates the rotor shaft, connects the internal space of the shaft to the external space where the rotor is disposed within the motor housing. Furthermore, it allows the oil supplied to the internal space by the helical structure to flow from the internal space to the external space. The spiral structure extends axially to the position where the through hole is provided.

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