Cooling apparatus

Abstract

To provide a cooling apparatus in which fuel consumption and electricity consumption can be improved while maintaining lubrication of a bearing.SOLUTION: A cooling apparatus 10 comprises: multiple outlet sections 12 for introducing an oil Co toward a first bearing 5 and a stator 7; a storage section 13 for storing the oil Co introduced from the outlet section 12 toward the first bearing 5 so that at least the lower end of the first bearing 5 is immersed in the oil Co; and an opening / closing section 15 for opening / closing the storage section 13. The opening / closing section 15 includes: maintaining the storage section 13 at a close state when the temperature of the oil Co is lower than a predetermined temperature; and putting the storage section 13 into an open state by mechanical deformation when the temperature of the oil Co is equal to or higher than the predetermined temperature.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a cooling device. [Background technology]

[0002] Patent Document 1 describes a cooling system applied to a vehicle equipped with a motor and a generator. In this system, oil discharged from a pump is cooled in an oil cooler, then supplied to the generator, and then taken back into the pump, thereby circulating the oil. This system has an introduction path that introduces the oil cooled in the oil cooler into the housing and supplies it to the stator, bearings, etc. In this system, the bottom of the generator housing is used as a reservoir where the oil accumulates. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-034818 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a motor cooling device, for example, when the outside temperature is low or the motor is operating at a low load, it is possible to improve fuel efficiency and electricity consumption by stopping the pump and halting the circulation of oil. However, in the cooling system described in the above Patent Document 1, stopping the pump stops the supply of oil to the bearings, and the bearings are no longer lubricated, making it difficult to stop the pump.

[0005] An object of the present disclosure is to provide a cooling device that can improve fuel efficiency and power efficiency while maintaining lubrication of bearings. [Means for solving the problem]

[0006] The cooling device of the present disclosure is a cooling device that uses oil to lubricate and cool an electric motor that includes a shaft, a rotor attached to the shaft, a stator arranged to surround the rotor, and a bearing that rotatably supports the shaft, and includes a plurality of outlet sections for directing oil toward the bearings and the stator, a storage section for storing the oil directed from the outlet sections toward the bearings so that at least the lower end of the bearing is immersed in the oil, and an opening / closing section for opening and closing the storage section, wherein the opening / closing section maintains the storage section in a closed state when the oil is lower than a predetermined temperature, and mechanically deforms to open the storage section when the oil is at or above the predetermined temperature.

[0007] This cooling device includes a plurality of outlets for leading out oil toward the bearings and the stator. Therefore, for example, when the motor is operating under high load, the oil is transferred by a pump or the like and led out from the outlets, thereby cooling the bearings and the stator while lubricating the bearings with the oil. On the other hand, this cooling device includes a storage section for storing the oil led out toward the bearings so that at least the lower end of the bearing is immersed in the oil, and an opening / closing section that maintains the storage section in a closed state when the oil is lower than a predetermined temperature and mechanically deforms to open the storage section when the oil is at or above the predetermined temperature. Therefore, when the temperature of the oil is low, such as when the motor is under low load, the storage section is closed and the oil remains stored so that the bearings are immersed. Therefore, in this case, even if the transfer of oil by the pump or the like is stopped, the lubrication of the bearings is maintained. Therefore, it is possible to improve fuel efficiency and electricity efficiency by stopping the pump or the like while maintaining the lubrication of the bearings. On the other hand, in this cooling device, when the oil is hot, the storage section opens due to mechanical deformation of the opening and closing section, so the circulation of the oil through the bearing is not impeded. In this cooling device, the storage section opens and closes due to mechanical deformation of the opening and closing section according to the temperature. Therefore, no temperature sensor or complicated structure is required to open and close the storage section.

[0008] The cooling device according to the present disclosure includes a dam member for forming a storage section between a wall section in which a bearing is embedded in a housing of an electric motor, the dam member is formed with a discharge port for discharging oil stored in the storage section, and the opening / closing section may be provided on the dam member so as to cover the discharge port. In this case, since the opening / closing section is provided so as to cover a part (discharge port) of the dam member that forms the storage section between the housing and the opening / closing section, it is possible to easily and reliably open and close the storage section.

[0009] In the cooling device according to the present disclosure, the dam member may be used in common with the member for preventing the bearing from coming off the housing. In this case, it is possible to reduce the number of parts and costs while improving fuel efficiency and electricity efficiency while maintaining lubrication of the bearing. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a cooling device that can improve fuel efficiency and power efficiency while maintaining lubrication of bearings. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view of a motor according to this embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view taken along the line II-II shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a motor according to an embodiment will be described with reference to the drawings. In the description of each drawing, the same or corresponding elements are denoted by the same reference numerals, and duplicated description may be omitted.

[0013] Fig. 1 is a schematic cross-sectional view of a motor according to this embodiment. The motor 1 (electric motor) shown in Fig. 1 can be mounted on electric vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell electric vehicles (FCEVs), and battery electric vehicles (BEVs).

[0014] The motor 1 includes a housing 2, a shaft 3, a rotor 4, a first bearing 5, a second bearing 6, a stator 7, and a cooling device 10. The housing 2 accommodates a part (tip portion) of the shaft 3, the rotor 4, the first bearing 5, the second bearing 6, and the stator 7. The housing 2 is composed of a tubular (for example, cylindrical) side wall portion 2a, a bracket 2b attached to one end of the side wall portion 2a, and a bottom wall portion 2c formed integrally with the side wall portion 2a at the end of the side wall portion 2a opposite to the bracket 2b.

[0015] The shaft 3 is a rod-shaped member extending in one direction. The shaft 3 is supported rotatably around an axis along the extension direction of the shaft 3 (hereinafter referred to as the "first direction") by a first bearing 5 and a second bearing 6 that are arranged apart from each other in the extension direction of the shaft 3. The shaft 3 is a member that transmits power to, for example, an external device by rotating due to the torque generated by the motor 1.

[0016] The rotor 4 is provided on the shaft 3. The rotor 4 is a cylindrical member that rotates together with the shaft 3. The rotor 4 has, for example, a permanent magnet (in the case of a synchronous machine) or a cage-shaped aluminum (in the case of an induction machine) disposed therein for forming a rotor magnetic field. The rotor 4 rotates around an axis along the first direction in conjunction with the shaft 3 due to the interaction between the rotor magnetic field and a stator magnetic field formed by the stator 7.

[0017] The stator 7 is a tubular (here, cylindrical) member provided so as to surround the rotor 4 along the first direction D1. The stator 7 includes a stator core 7a and a coil 7b. The stator core 7a can be formed, for example, by laminating and welding electromagnetic steel sheets. The coil 7b for forming a stator magnetic field is wound around the stator core 7a. Coil ends, which are parts of the coil 7b, are formed and protrude from both ends of the stator core 7a in the first direction.

[0018] The stator 7 may be fixed to the housing 2 by other members such as a stator bolt. The motor 1 is, for example, a three-phase AC motor. In this case, the coil 7b may be configured by arranging a plurality of portions corresponding to the U-phase, V-phase, and W-phase layers along the circumferential direction of the stator 7.

[0019] The first bearing 5 is held, for example, by being fitted into a recess provided in the bracket 2b. As an example, when the first bearing 5 is inserted into the recess provided in the bracket 2b, it is fixed so as not to come off from the bracket 2b by a plate-shaped retaining member 8 provided from the bracket 2b to the first bearing 5. The second bearing 6 is held, for example, by being fitted into a recess provided in the bottom wall portion 2c. That is, at least a portion of the first bearing 5 is embedded in the bracket 2b, and at least a portion of the second bearing 9b is embedded in the bottom wall portion 2c.

[0020] 2 is a schematic cross-sectional view taken along line II-II in FIG. 1. As shown in FIGS. 1 and 2, the cooling device 10 is for performing lubrication and cooling using oil. The cooling device 10 has a cooling pipe 11 through which the oil Co flows. The cooling pipe 11 is provided penetrating from the outside of the housing 2 to the inside of the housing 2. One end of the cooling pipe 11 is connected to an electric oil pump (not shown) for transporting the oil Co. The cooling pipe 11 is provided with a plurality of outlet portions 12 for guiding the oil Co that has flowed through the cooling pipe 11 toward the first bearing 5, the second bearing 6, and the stator 7.

[0021] The cooling pipe 11 extends from one end to the other end of the housing 2 along the first direction, and the outlet portions 12 are provided spaced apart from one another along the first direction. Some of the outlet portions 12 are provided on each of a pair of coil ends of the coil 7b. The oil Co led out from the outlet portions 12 drips onto the bottom portion 2p of the housing 2 while cooling the coil ends.

[0022] Another part of the outlet portion 12 is provided on the stator core 7a. The oil Co led out from the outlet portion 12 drips onto the bottom 2p of the housing 2 while cooling the stator core 7a. At least a part of the oil Co flowing through the cooling pipe 11 and dripping from the outlet portion 12 can be stored in the bottom 2p of the housing 2. The oil Co stored in the bottom 2p of the housing 2 can be discharged to the outside of the housing 2 using, for example, a discharge portion and an electric oil pump (neither of which are shown) provided in the bottom 2p, and can be circulated to the cooling pipe 11 after being cooled, for example.

[0023] Another part of the multiple outlet parts 12 is provided on the first bearing 5 and the second bearing 6. The oil Co output from the outlet part 12 is supplied to the first bearing 5 and the second bearing 6, for example, through the bracket 2b or the bottom wall part 2c, and is used for cooling and lubricating the first bearing 5 and the second bearing 6.

[0024] The cooling device 10 has a storage section 13 that stores the oil Co, which is guided from the outlet section 12 toward the first bearing 5, in the first bearing 5. The storage section 13 stores the oil Co such that at least the lower end of the first bearing 5 is immersed in the oil Co. The storage section 13 is formed between the bracket 2b, which is a wall section in the housing 2 in which the first bearing 5 is embedded, and the dam member 14 by providing the dam member 14 to the bracket 2b. Note that a retaining member 8 may be interposed between the dam member 14 and the bracket 2b.

[0025] The dam member 14 is a semicircular plate-shaped member provided so as to overlap at least the lower end of the first bearing 5 when viewed from the first direction. The dam member 14 is formed with a discharge port 14p for discharging the oil Co stored in the storage portion 13. The dam member 14 is provided with an opening / closing portion 15 so as to cover the discharge port 14p.

[0026] The opening / closing unit 15 is for opening and closing the storage unit 13. The opening / closing unit 15 is formed in a plate shape from a material (e.g., bimetal) that mechanically deforms in response to temperature changes. As a result, the opening / closing unit 15 closes the discharge port 14p when the oil Co stored in the storage unit 13 is lower than a predetermined temperature, thereby maintaining the storage unit 13 in a closed state. Furthermore, the opening / closing unit 15 mechanically deforms when the oil Co is at or above a predetermined temperature, opening the discharge port 14p and opening the storage unit 13.

[0027] As described above, the cooling device 10 includes a plurality of outlet portions 12 for guiding the oil Co toward the first bearing 5, the second bearing 6, and the stator 7. Therefore, for example, when the motor 1 is operating under high load, the oil Co is transported by an electric oil pump (not shown) and is guided out from the outlet portions 12, whereby the first bearing 5, the second bearing 6, and the stator 7 can be cooled while the first bearing 5, the second bearing 6, and the stator 7 are lubricated by the oil Co.

[0028] On the other hand, the cooling device 10 includes a storage section 13 for storing the oil Co guided toward the first bearing 5 so that at least the lower end of the first bearing 5 is immersed in the oil Co, and an opening / closing section 15 for maintaining the storage section 13 in a closed state when the oil Co is lower than a predetermined temperature, and mechanically deforming to open the storage section 13 when the oil Co is at or above the predetermined temperature. Therefore, when the temperature of the oil Co is low, such as when the motor 1 is under low load, the storage section 13 is closed, and the oil Co remains stored so that the first bearing 5 is immersed. Therefore, in this case, even if the electric oil pump is stopped to stop the transfer of the oil Co, the lubrication of the first bearing 5 is maintained. Therefore, it is possible to improve fuel efficiency and electricity efficiency by stopping the electric oil pump while maintaining the lubrication of the first bearing 5.

[0029] On the other hand, in the cooling device 10, when the oil Co is at a high temperature, the storage section 13 is opened by mechanical deformation of the opening / closing section 15, so that the circulation of the oil Co through the first bearing 5 is not impeded. In the cooling device 10, the storage section 13 is opened and closed by mechanical deformation of the opening / closing section 15 according to the temperature. Therefore, a temperature sensor or a complicated structure for opening and closing the storage section 13 is not required.

[0030] The cooling device 10 also includes a dam member 14 for forming the storage section 13 between itself and a wall section (bracket 2b) in which the first bearing 5 is embedded in the housing 2 of the motor 1. The dam member 14 is formed with an outlet 14p for discharging the oil Co stored in the storage section 13. The opening / closing section 15 is provided in the dam member 14 so as to cover the outlet 14p. In this way, the opening / closing section 15 is provided so as to cover a part (outlet 14p) of the dam member 14 that forms the storage section 13 between itself and the housing 2, so that the storage section 13 can be opened and closed easily and reliably.

[0031] The above embodiment describes one aspect of the present invention, therefore, the present invention is not limited to the above embodiment and can be modified as desired.

[0032] For example, in the above embodiment, a configuration has been described in which the dam member 14 is provided separately from the retaining member 8 for the first bearing 5. However, the dam member 14 may be formed in common with the retaining member 8. In other words, in the cooling device 10, the retaining member 8 may form a reservoir 13 that retains the oil Co such that at least the lower end of the first bearing 5 is immersed in the oil Co. In this case, it is possible to reduce the number of parts and costs when improving fuel efficiency and power efficiency while maintaining the lubrication of the first bearing 5.

[0033] In the above embodiment, the configuration in which the storage section 13, the dam member 14, and the opening / closing section 15 are provided for the first bearing 5 has been described, but a similar configuration can also be adopted for the second bearing 6.

[0034] Furthermore, in the above embodiment, a configuration has been described in which the discharge port 14p is provided in the dam member 14 forming the storage portion 13, and the discharge port 14p is opened and closed by the opening / closing portion 15. However, the dam member 14 may be omitted by using an opening / closing portion 15 having a similar shape to the dam member 14. That is, the storage portion 13 may be formed between the opening / closing portion 15 and the bracket 2b. In this case, the opening / closing portion 15 is mechanically deformed in response to a temperature change, thereby generating a gap between the opening / closing portion 15 and the bracket 2b, and the storage portion 13 can be opened. [Explanation of symbols]

[0035] 1...motor (electric motor), 2...housing, 3...shaft, 4...rotor, 5...first bearing, 6...second bearing, 7...stator, 8...anti-pullout member, 10...cooling device, 12...outlet portion, 13...storage portion, 14...dam member, 14p...discharge port, 15...opening / closing portion.

Claims

1. A cooling device that performs lubrication and cooling with oil in an electric motor including a shaft, a rotor provided on the shaft, a stator provided so as to surround the periphery of the rotor, and a bearing that rotatably supports the shaft, a plurality of outlet portions for guiding the oil toward the bearing and the stator; a reservoir for storing the oil guided from the outlet toward the bearing such that at least a lower end of the bearing is immersed in the oil; An opening / closing unit for opening and closing the storage unit; Including, the opening / closing portion maintains the storage portion in a closed state when the oil is at a temperature lower than a predetermined temperature, and mechanically deforms to open the storage portion when the oil is at or above the predetermined temperature. Cooling device.

2. a dam member for forming the storage portion between the dam member and a wall portion of the housing of the electric motor in which the bearing is embedded, The dam member is formed with a discharge port for discharging the oil stored in the storage portion, The opening / closing portion is provided on the dam member so as to cover the discharge port. The cooling device according to claim 1 .

3. The dam member is also used as a member for preventing the bearing from coming off the housing. The cooling device according to claim 2.

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