Drive device for hybrid system

Abstract

To provide a drive unit for a hybrid system which prevents deterioration of cooling performance caused by air bubbles generated by agitation of oil while keeping the number of components low.SOLUTION: A drive unit 1 for a hybrid system includes: an oil-cooled motor with a rotary shaft 11 to which an output of an engine is transmitted being an output shaft; a transmission (AT gear 13) to which power is transmitted from the rotating shaft 11; and a housing 10 having a partition wall part that partitions a motor chamber which accommodates the motor and a transmission chamber which accommodates the transmission. Oil is stored in a bottom of the housing 10, and the partition wall part P comprises a communication oil path 120 that provides communication between the motor chamber M and the transmission chamber G at the bottom of the housing 10.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a drive device for a hybrid system.

Background Art

[0002] As a drive device for a hybrid system, it is known to use an oil-cooled motor.

[0003] Patent Document 1 discloses a clutch and motor housing structure for a hybrid electric vehicle. This is an attachment structure of an air breather that suppresses a pressure increase in a clutch housing that houses a wet hydraulic clutch for transmitting driving force from an engine to a transmission side and a motor housing that houses an oil-cooled driving motor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When bubbles generated by oil agitation cover the coil or rotor in the motor chamber, the cooling performance deteriorates. Therefore, a method of providing a breather is known. However, providing a breather increases the number of parts.

[0006] The present invention has been made to solve such problems, and an object thereof is to provide a drive device for a hybrid system that suppresses an increase in the number of parts and prevents a decrease in cooling performance due to bubbles generated by oil agitation.

Means for Solving the Problems

[0007] A drive device for a hybrid system according to an aspect of the present invention is An oil-cooled motor having a rotating shaft to which the output of the engine is transmitted as an output shaft, A transmission to which power is transmitted from the rotating shaft, A housing including a partition wall portion that separates a motor chamber that houses the oil-cooled motor and a transmission chamber that houses the transmission, having, Oil is stored at the bottom of the housing, The partition wall portion includes a communication oil passage that communicates the motor chamber and the transmission chamber at the bottom of the housing.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to provide a drive device for a hybrid system that suppresses an increase in the number of parts and prevents a decrease in cooling performance due to bubbles generated by oil agitation.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are denoted by the same reference numerals, and redundant descriptions are omitted as necessary for clarity of explanation.

[0011] FIG. 1 is a cross-sectional view of a drive device 1 for a hybrid system according to an embodiment. FIG. 1 illustrates a drive device for a front-engine rear-drive hybrid vehicle. The drive device 1 for a hybrid system includes a motor generator (rotating electrical machine) MG, a rotating shaft 11 connected to an engine, and an AT (Automatic Transmission) gear 13 connected to the rotating shaft 11. The motor generator may also be simply called a motor. The drive device 1 for a hybrid system is housed in a housing 10. Specifically, FIG. 1 is a view of the housing 10 seen from the side of the vehicle. The housing 10 has a front motor chamber M, a rear gear chamber G, and a partition portion P that separates the motor chamber M and the gear chamber G. The motor chamber M is also called a motor case. The gear chamber G is also called a gear case, a transmission chamber, or a transmission case.

[0012] Although not shown, an engine is disposed in front of the drive device 1. The engine (not shown) is an internal combustion engine that converts the reciprocating motion of a piston into the rotational motion of a crankshaft (rotating shaft) using fuel such as gasoline or light oil. The motor chamber M houses an oil-cooled motor generator MG having a rotating shaft 11 to which the output of the engine is transmitted as an output shaft. The motor generator MG includes a stator 100 and a rotor 200 housed in the motor chamber M. The stator 100 includes an annular stator core 101 and a stator coil 102 wound around the stator core 101. The rotor 200 includes a rotor core 201 and end plates 202 and 203 disposed on both sides in the axial direction of the rotor core 201. The rotor core 201 is formed by laminating a plurality of electromagnetic steel sheets formed in an annular shape by, for example, press working. Further, a plurality of through holes (not shown) extending in the axial direction are formed in the rotor core 201 at intervals in the circumferential direction, and permanent magnets are embedded in each through hole. In a motor with a large amount of heat generation such as a hybrid motor, an oil-cooling method is generally used in which oil for cooling and lubrication is applied to the core and the coil ends.

[0013] As shown in FIG. 1, on the outer periphery of one end (front end), i.e., the open end side, of the outer shell portion 81 of the motor chamber M of the housing 10, a front flange portion 81f having a plurality of bolt holes is formed. The front flange portion 81f is fastened (fixed) to the engine block of the engine via a plurality of bolts (not shown) inserted through the corresponding bolt holes. Further, the other end portion of the outer shell portion 81 protrudes to the side opposite to the front flange portion 81f with respect to the end wall 82, and on the outer periphery of the other end (rear end) of the outer shell portion 81, a rear flange portion 81r having a plurality of bolt holes is formed. The rear flange portion 81r is fastened (fixed) to the front end of the transmission case (gear chamber G) of the power transmission device via a plurality of bolts inserted through the corresponding bolt holes.

[0014] The motor chamber M of the housing 10 is formed by casting an aluminum alloy, and includes a cylindrical outer shell portion 81 and an end wall (wall portion) 82 closing the other end of the outer shell portion 81. The motor case includes a motor chamber M with one end open and a cover 88 fixed so as to cover the one end. The cover 88 is fixed to the motor chamber M of the housing 10 via a plurality of bolts. The cover 88 forms an end wall portion of the motor case extending in the radial direction so as to face the motor generator MG and the clutch K0 on the engine side. The clutch K0 connects the rotary shaft 11a, i.e., the crankshaft of the engine, and the rotary shaft (transmission shaft) 11b, i.e., the rotor 200 of the motor generator MG, and releases the connection between the two.

[0015] Similarly, the gear chamber G of the housing 10 is formed by casting an aluminum alloy, and includes a cylindrical outer shell portion 91 and an end wall (wall portion) 92 closing the other end of the outer shell portion 91. The gear case includes a gear chamber G with one end open and a cover 98 fixed so as to cover the one end. The cover 98 is fixed to the gear chamber G of the housing 10 via a plurality of bolts 99. The gear chamber G houses a transmission (AT gear 13 in FIG. 1) to which the power from the rotary shaft 11 is transmitted. In this example, the rotary shaft in the motor chamber and the rotary shaft in the gear chamber are the same single shaft. The rotary shafts 11a to 11c are collectively referred to as the rotary shaft 11.

[0016] Oil is stored at the bottom of the housing 10. This oil is also called ATF (Automatic Transmission Fluid). Specifically, in the housing 10, an oil pan 110 is formed at the bottom 111 of the motor chamber M, and an oil pan 130 is formed at the bottom 131 of the gear chamber G. In the gear chamber G, the AT gear 13 is symmetrically configured with respect to the rotating shaft 11, and the oil pan 130 is provided below the lower end (dashed line) of the AT gear 13. Further, adjacent to the rear of the oil pan 130 in the gear chamber G, an oil pump 140 for circulating the oil along the path shown in FIG. 2 is provided. From the above, at the bottom of the housing 10, the oil pan 110, the communication oil passage 120, and the oil pan 130 form a liquid layer SL in which the oil is stored.

[0017] Also, the volume of the oil pan 130 is designed to be larger than the volume of the oil pan 110. That is, the oil pan 130 is designed to be longer in the front-rear direction than the oil pan 110 and is also designed to be longer in the vertical direction. Further, the lower end of the oil pan 130 is designed to be lower than the lower end of the oil pan 110. Thereby, the oil is designed to flow from the oil pan 110 in the motor chamber M to the oil pan 130 in the transmission chamber G. Note that the upper surface of the liquid layer SL can be designed to be disposed downward by a predetermined distance H from the lower end of the AT gear 13.

[0018] The oil level of the oil in the oil pan 130 may rise or fall due to an increase in the temperature of the ATF or a change in the posture of the vehicle during travel. When the oil level of the ATF at the bottom of the gear chamber G rises and touches the AT gear 13, this oil may be agitated as the AT gear 13 rotates, and bubbles may be generated (bubble layer AB in FIG. 1). Thereafter, when the oil level of the ATF drops, the generated bubbles may reach the motor chamber M and cover the motor coil 102 and the rotor 200, which may inhibit the cooling performance (heat dissipation).

[0019] Therefore, in the present disclosure, in order to solve such problems, the motor chamber M and the gear chamber G are separately arranged, and at the bottom of the partition wall P that separates them, an oil communication oil passage 120 is provided to prevent the inflow of bubbles into the motor chamber M. The communication oil passage 120 is arranged at a position slightly higher than the bottom 111 of the oil pan 110 and the bottom 131 of the oil pan 130, and is provided to communicate the oil pan 110 and the oil pan 130. The length of the communication oil passage 120 in the longitudinal direction of the vehicle may be equal to or greater than a predetermined distance. Specifically, the oil communication oil passage 120 is provided at a position below the lower end of the AT gear 13 by a predetermined distance D. This predetermined distance can be arbitrarily set so that bubbles generated by the rotation of the AT gear 13 are less likely to reach or completely reach the motor chamber M.

[0020] In some embodiments, the housing 10 may be designed such that the oil level of the ATF is above the communication oil passage 120. As a result, since the ATF fills the communication oil passage 120, the backflow of bubbles into the motor chamber can be suppressed as much as possible.

[0021] During driving, when the vehicle is tilted to the left, since the bubble layer AB where bubbles can be generated in the transmission chamber is above the communication oil passage 120, the inflow of bubbles into the motor chamber is suppressed. On the other hand, during driving, when the vehicle is tilted to the right, the ATF is biased toward the transmission chamber side, so the inflow of bubbles into the motor chamber is suppressed.

[0022] FIG. 2 is a schematic diagram showing the flow path of the ATF of the drive device for a hybrid system according to an embodiment. The oil stored in the oil pan 130 of the AT section (transmission chamber) is sent by the oil pump 140 through an oil passage to the heat exchanger 150 of the radiator of the vehicle. The oil cooled by the heat exchange 150 further reaches the motor chamber M through the oil passage in the axis of the rotating shaft 11. As the rotating shaft 11 rotates, the oil is scattered onto the motor MG, takes away the heat of the motor MG, and then is stored in the oil pan 110 of the motor chamber M.

[0023] Similarly, the oil cooled by the heat exchanger 150 further reaches the transmission chamber G through the oil passage within the axis of the rotating shaft 11. Along with the rotation of the rotating shaft 11, the oil is scattered onto the AT gear 13, takes away the heat of the AT gear 13, and then is stored in the oil pan 130 of the transmission chamber G.

[0024] The above-described oil communication passage 120 communicates the oil pan 110 of the motor chamber M with the oil pan 130 of the transmission chamber G. As shown in FIG. 2, the oil is designed to flow from the oil pan 110 of the motor chamber M to the oil pan 130 of the transmission chamber G, preventing the backflow of the bubbles generated on the oil pan 130 side by the AT gear 13 in the transmission chamber G into the motor chamber.

[0025] The oil stored in the oil pan 110 and the oil pan 130 is sent again by the oil pump 140 to the heat exchanger 150 and the radiator. The heat exchanger 150 performs heat exchange between the oil and the outside. The high-temperature oil that has taken away heat from the motor and the gear is cooled by the heat exchanger 150.

[0026] The drive device for a hybrid system according to the embodiment described above can prevent a decrease in cooling performance caused by bubbles generated by oil agitation while suppressing an increase in the number of parts such as a breather.

[0027] Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist.

Explanation of Reference Numerals

[0028] M Motor chamber P Partition portion G Gear chamber (transmission chamber) MG Motor generator K0 Clutch AB Bubble layer SL Liquid layer 1 Drive device for a hybrid system 10 Housing 11 (11a~11c) Rotating shaft 13 AT gear 81 Outer shell part 91 Outer shell part 100 Stator 110 Oil pan 111 Bottom part 120 Communication oil passage 130 Oil pan 131 Bottom part 140 Oil pump 150 Heat exchanger 200 Rotor

Claims

1. An oil-cooled motor having a rotating shaft to which the output of an engine is transmitted as an output shaft, A transmission to which power is transmitted from the rotating shaft, A housing including a partition wall portion that separates a motor chamber that houses the oil-cooled motor and a transmission chamber that houses the transmission, And having, An oil pan of the motor chamber and an oil pan of the transmission chamber are provided at the bottom of the housing, The partition wall portion includes a communication oil passage that communicates the motor chamber and the transmission chamber at the bottom of the housing, The communication oil passage is provided downward by a predetermined distance from the lower end of the transmission so that air bubbles generated in the transmission chamber do not flow into the motor chamber, At the bottom of the housing, a liquid layer in which oil is stored is formed in the oil pan of the motor chamber, the communication oil passage, and the oil pan of the transmission chamber, and the upper surface of the liquid layer is provided downward by a predetermined distance from the lower end of the transmission., A drive device for a hybrid system.

2. The oil stored in the oil pan of the transmission chamber is sent by an oil pump through an oil passage to a heat exchanger of a radiator of a vehicle, and the oil cooled by the heat exchanger further passes through an oil passage in the axis of the rotating shaft and reaches the motor chamber. The oil is scattered onto the oil-cooled motor as the rotating shaft rotates, taking away the heat of the oil-cooled motor, and then is configured to be stored in the oil pan of the motor chamber. The drive device for a hybrid system according to claim 1.

3. The communication oil passage is configured to be filled with oil, The oil cooled by the heat exchanger of the radiator of the vehicle further passes through an oil passage in the axis of the rotating shaft and reaches the transmission chamber. The oil is scattered onto the transmission as the rotating shaft rotates, taking away the heat of the transmission, and then is configured to be stored in the oil pan of the transmission chamber. The drive device for a hybrid system according to claim 2.

4. The volume of the oil pan formed at the bottom of the transmission chamber is configured to be larger than the volume of the oil pan formed at the bottom of the motor chamber, the drive device for a hybrid system according to any one of claims 1 to 3.

5. The drive device is for a front-engine rear-drive type automobile, the drive device for a hybrid system according to any one of claims 1 to 4.

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