CN210129802U

CN210129802U - Cooling structure of motor

Info

Publication number: CN210129802U
Application number: CN201921198076.4U
Authority: CN
Inventors: 浅井孝宪
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2019-07-26
Filing date: 2019-07-26
Publication date: 2020-03-06
Anticipated expiration: 2029-07-26

Abstract

The utility model provides a cooling structure of motor. The cooling structure is provided with a cooling channel which is arranged along a stator core and an end coil of the motor, wherein a core side discharge hole is formed at a position corresponding to the stator core in the cooling channel; a coil-side discharge hole is formed in a portion corresponding to the end coil, and a regulating valve that opens and closes in accordance with the pressure of the fluid flowing through the cooling passage is disposed in the coil-side discharge hole. Based on the above structure of the utility model, can be corresponding to the operation conditions of motor and suitably cool off the object that needs the cooling in stator core and the end coil.

Description

Cooling structure of motor

Technical Field

The utility model relates to a cooling structure of motor.

Background

Conventionally, as a cooling structure of a motor, a cooling structure including a cooling pipe through which cooling oil flows is known. In this configuration, discharge ports for discharging cooling oil are provided in the cooling pipe at positions corresponding to the two end coils of the motor, and a control valve is disposed in each discharge port. The control valve has a function of switching between a small hole and a large hole in accordance with the pressure of the cooling oil flowing through the cooling pipe.

In the cooling structure of the prior art described above, the regulating valve communicates the small hole with the discharge port at the end of the cooling pipe where the pressure of the cooling oil is high; the regulating valve connects the large hole to the discharge port at the end of the cooling pipe where the pressure of the cooling oil is low. Therefore, even if the pressures of the cooling oil in the respective portions in the cooling pipe are different, the difference in the discharge flow rate between the cooling oil discharged from the discharge port at one end to the end coil at one end and the cooling oil discharged from the discharge port at the other end to the end coil at the other end can be suppressed, and the end coils at both ends can be cooled uniformly.

In general, in a motor mounted on a vehicle such as an electric vehicle, it is necessary to preferentially cool an end coil or a stator core according to an operating condition of the motor.

However, the above-described conventional structure can cool only the end coils at both ends equally. In addition, even if the structure of the prior art is slightly changed, the discharge port at one end faces the end coil; the discharge port at the other end faces the stator core, and the end coil and the stator core can be cooled equally, but one of the end coil and the stator core cannot be selectively cooled preferentially according to actual needs (heat generation conditions).

SUMMERY OF THE UTILITY MODEL

In view of the above, an object of the present invention is to provide a motor cooling structure capable of appropriately cooling an object to be cooled, among an end coil and a stator core, in accordance with an operation state of the motor.

As a means for solving the above-described problems, the present invention provides a cooling structure for a motor, including a cooling passage disposed along a stator core and an end coil of the motor, the cooling passage having a core-side discharge hole formed at a position corresponding to the stator core; a coil-side discharge hole is formed in a portion corresponding to the end coil, and a regulating valve that opens and closes in accordance with a pressure of the fluid flowing through the cooling passage is disposed in the coil-side discharge hole.

Based on the utility model discloses a cooling structure of above-mentioned motor, when the motor is high rotational speed low torque, the electric current in the stator coil is less, therefore compares with stator coil, and stator core's generating heat seriously more needs to be cooled off. In this state, since the pressure of the fluid in the cooling passage is low, the control valve is closed and the fluid cannot be discharged from the coil-side discharge hole, so that the fluid in the cooling passage is mainly discharged from the core-side discharge hole to the stator core to preferentially cool the stator core. In this state, since the pressure of the fluid in the cooling passage is high, the regulator valve opens, and a part of the fluid in the cooling passage is discharged from the coil-side discharge hole to the end coil, thereby cooling the end coil.

That is, according to the cooling structure of the motor of the present invention, the object to be cooled of the end coils and the stator core can be appropriately cooled according to the operating state of the motor. As a result, the total amount of fluid supplied to the cooling passage can be reduced, and the fluid pump can be downsized, and the cooling performance of the motor can be improved, and the fuel cost of the electric vehicle or the like can be reduced.

In the cooling structure of the motor according to the present invention, it is preferable that the regulating valve is formed of an elastically deformable elastic member, and the elastic member is formed with a slit having a predetermined shape that penetrates an upstream end and a downstream end in a discharge direction of the fluid at the coil side discharge hole. Based on this structure, enable governing valve simple structure and low in cost. That is, when the pressure of the fluid in the cooling passage exceeds a predetermined value, the slit in the elastic member is ruptured to open the regulator valve; conversely, when the pressure of the fluid in the cooling passage is below a predetermined value, the slit in the elastic member is closed to close the control valve. Since the regulating valve can be constructed by merely forming the slits in the elastic member, the regulating valve is simple in structure and inexpensive in cost.

Drawings

Fig. 1 is a sectional view showing a main component of a motor according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view of the core-side discharge hole of the cooling pipe of the motor and its surroundings.

Fig. 3 is a cross-sectional view of a coil-side discharge hole of a cooling pipe provided in the motor and its periphery.

Fig. 4 is a front view of the regulating valve disposed in the coil side discharge hole.

Fig. 5 is a front view of the coil side exhaust hole.

Detailed Description

Hereinafter, a cooling structure of a motor according to an embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a sectional view showing a main component of a motor in the present embodiment. As shown in fig. 1, a motor 1 installed in a vehicle such as an electric vehicle is, for example, a motor for driving the vehicle, and includes a rotor 6 and a stator 10. The rotor 6 is made of electromagnetic steel plates laminated together and fixed to the rotor shaft 5. The rotor shaft 5 is rotatably supported by a housing 8 via a bearing 7, and an output shaft 9 is fitted therein.

The stator 10 has a stator core 11 and a stator coil 12 covered with an insulating material. The stator core 11 is formed of stacked hollow cylindrical electromagnetic steel plates, and the rotor 6 is disposed in an inner space thereof at a predetermined interval. The stator coil 12 is wound around the stator core 11, and

end coils

12a and 12b protruding from both ends of the stator 10 in the axial direction (the left-right direction in fig. 1) are formed outside the both ends.

A cooling pipe 15 constituting a cooling passage is disposed directly above the stator 10 in the direction of gravity. The cooling pipe 15 extends parallel to the axial direction of the output shaft 9, and both ends thereof extend to the outer side than the

end coils

12a, 12 b. Further, in the cooling pipe 15, a core-side discharge hole 17 is formed at a position corresponding to an axial middle portion of the stator core 11; coil-

side discharge holes

19a and 19b are formed at positions corresponding to the

end coils

12a and 12b, respectively.

A part of the fluid discharged from the fluid pump 20 is supplied into the cooling pipe 15. The Fluid pump 20 is a mechanical pump driven by the motor 1, is disposed in an automatic transmission of a vehicle (not shown), and is configured to discharge a Fluid (for example, ATF: automatic transmission Fluid) for lubrication, cooling, and washing of a transmission mechanism in the automatic transmission, and to supply a part of the discharged Fluid into the cooling pipe 15.

Fig. 2 is a sectional view of the cooling pipe 15 at the core-side discharge hole 17, and fig. 3 is a sectional view of one end of the cooling pipe 15 at the coil-side discharge hole 19 a. The cross-sectional view of the coil-side discharge hole 19b at the other end is the same as the cross-sectional view of the coil-side discharge hole 19a, and therefore, illustration thereof is omitted. In fig. 2 and 3, the cooling pipe 15 has a circular cross section, but the cross-sectional shape of the cooling pipe 15 may be other shapes.

As shown in fig. 2, two core-side discharge holes 17 are formed in the cooling pipe 15, and the positions of the two core-side discharge holes 17 overlap each other in fig. 1, and the two core-side discharge holes 17 are located at positions corresponding to 5 o 'clock and 7 o' clock, respectively (positions rotated by about 30 ° clockwise and counterclockwise with respect to the vertical direction), respectively, in the cross section shown in fig. 2. A part of the fluid supplied to the cooling pipe 15 is ejected from each core-side discharge hole 17 toward the middle portion of the stator core 11 as indicated by arrows in fig. 2, thereby cooling the stator core 11. The fluid that cools the stator core 11 falls by its own weight and finally falls to the bottom of the housing 8.

On the other hand, as shown in fig. 3, two coil-side discharge holes 19a are formed in the cooling pipe 15, and like the core-side discharge holes 17, the positions of the two coil-side discharge holes 19a overlap in fig. 1, and the two coil-side discharge holes 19a are located at positions corresponding to 5 and 7 points of the hour hand in the cross section shown in fig. 3. A part of the fluid supplied to the cooling pipe 15 is ejected from each coil-side discharge hole 19a toward the end coil 12a as shown by arrows in fig. 3, thereby cooling the end coil 12 a. The fluid that has cooled the end coil 12a falls by its own weight and finally falls to the bottom of the case 8. The coil-side discharge hole 19b at the other end has the same configuration as the coil-side discharge hole 19a, and therefore, the description thereof is omitted.

As shown in fig. 3, the regulating valve 22 is disposed in the coil-side discharge hole 19 a. Next, the structure of the regulator valve 22 will be described in detail with reference to fig. 3 to 5. Fig. 4 is a front view of the regulating valve 22 disposed in the coil-side discharge hole 19a, and fig. 5 is a front view of the coil-side discharge hole 19 a. The regulator valve 22 is constituted by a short cylindrical rubber member 23 as an elastic member. The rubber member 23 is configured such that its outer peripheral shape (circular shape here) coincides with the inner peripheral shape (circular shape here) of the coil-side discharge hole 19a, and is disposed in the coil-side discharge hole 19a with its front side facing the end coil 12a and its rear side facing the inside of the cooling pipe 15.

As shown in fig. 4, the rubber member 23 is formed with a slit of a predetermined shape, in the present embodiment, an X-shaped (substantially cross-shaped) slit 24, and the cross intersection of the X is located at the center of the cylindrical rubber member 23. The slit 24 penetrates from the front end surface of the rubber member 23 to the rear end surface of the rubber member 23, that is, penetrates the upstream end and the downstream end in the discharge direction of the fluid (the fluid discharged from the coil-side discharge hole 19a to the end coil 12 a). Similarly, the regulating valve 22 having the same configuration is disposed in the coil-side discharge hole 19b at the other end.

Normally, when the motor 1 has a high rotation speed and a low torque such as when the vehicle is traveling at a high speed, the current in the stator coil 12 of the motor 1 is small, and the stator 10 is in a state in which it is necessary to suppress heat generation due to the iron loss of the stator core 11 rather than heat generation due to the copper loss of the

end coils

12a and 12b of the stator coil 12. In this state, since the output of the motor 1 that drives the fluid pump 20 is low, the pressure of the fluid in the cooling pipe 15 is low. Therefore, the slits 24 of the rubber member 23 of the regulator valve 22 of the coil-

side discharge holes

19a and 19b at both ends of the cooling pipe 15 are closed by the low pressure of the fluid, and the coil-

side discharge holes

19a and 19b are closed. In this state, since the fluid cannot be discharged from the coil-

side discharge holes

19a, 19b, the cooling of the

end coils

12a, 12b by the fluid is stopped. At this time, since the core-side discharge holes 17 are opened, the low-pressure fluid can be discharged from the core-side discharge holes 17 to cool the stator core 11. In this way, when the motor 1 has a high rotation speed and a low torque, cooling of the end coils 12a and 12b having a small heat generation amount is stopped, and the fluid is discharged from the core-side discharge holes 17 to the stator core 11, so that the stator core 11 having a large heat generation amount due to the iron loss can be preferentially cooled.

On the contrary, when the motor 1 has a low rotation speed and a high torque such as when the vehicle is climbing a slope, the stator 10 needs to suppress heat generation due to the copper loss of the end coils 12a and 12b of the stator coil 12 as well as the iron loss of the stator core 11 because the current in the stator coil 12 of the motor 1 is large. In this state, since the output of the motor 1 that drives the fluid pump 20 is high, the pressure of the fluid in the cooling pipe 15 is high. Therefore, the slit 24 of the rubber member 23 of the regulator valve 22 of each of the two coil-side discharge holes 19a and 19b at both ends of the cooling pipe 15 is broken when the pressure of the fluid exceeds a predetermined value, and the coil-side discharge holes 19a and 19b are opened, and the opening area increases as the pressure of the fluid increases. As a result, the amount of fluid discharged from the core-side discharge holes 17 is reduced, and the stator core 11 is cooled by only a part of the fluid, while the other part of the fluid is discharged from the coil-side discharge holes 19a and 19b, thereby cooling the end coils 12a and 12b that generate heat more severely. Therefore, when the motor 1 is operated at a low rotation speed and high torque, a part of the fluid can be discharged from the coil-side discharge holes 19a and 19b, and the end coils 12a and 12b, which generate heat due to the flow of a large current, can be cooled.

As described above, according to the cooling structure of the motor 1 of the present embodiment, the object to be cooled among the stator core 11 and the end coils 12a and 12b can be appropriately cooled according to the operating state of the motor 1, and therefore, the cooling performance of the motor 1 can be improved. As a result, the total amount of fluid supplied to the cooling pipe 15 can be reduced, and the fluid pump 20 can be downsized, and the fuel cost of the vehicle can be reduced.

Further, since the regulating valve 22 disposed in the coil side discharge holes 19a and 19b is formed only by the rubber member 23 having the slit 24 formed therein, the structure is simple and the cost is low.

The present invention is not limited to the above embodiment, and can be modified as appropriate.

For example, in the above embodiment, the slit 24 formed in the rubber member 23 is formed in an X shape (substantially cross shape), but the present invention is not limited to this, and the slit 24 may be formed in other shapes, for example, a predetermined shape such as a-shape, ＊ -shape, or the like.

In the above embodiment, the rubber member 23 is used as the regulator valve 22, but the present invention is not limited to this, and the regulator valve 22 may be formed of another elastic material that can expand and contract (elastically deform) in accordance with the pressure applied thereto.

Claims

1. A cooling structure of a motor, characterized in that:

a cooling passage disposed along the stator core and the end coils of the motor,

a core-side discharge hole is formed in the cooling passage at a portion corresponding to the stator core; a coil-side discharge hole is formed at a portion corresponding to the end coil,

a regulating valve that opens and closes in accordance with the pressure of the fluid flowing through the cooling passage is disposed in the coil-side discharge hole.

2. The cooling structure of a motor according to claim 1, wherein:

the regulator valve is formed of an elastically deformable elastic member in which a slit having a predetermined shape is formed to pass through an upstream end and a downstream end in a discharge direction of the fluid at the coil-side discharge hole.