JPH0522133U - Cooling structure of electric motor for electric vehicle - Google Patents

Abstract

(57) [Abstract] [Purpose] To forcibly cool the inside of the outer rotor type wheel-in direct drive motor for electric vehicles. [Structure] Air is sucked through a filter 23 by a fan 24, and cooling air is sent into the electric motor 15 through a flexible duct 25, a hollow shaft 12, an intake port 12A thereof, a cylinder portion 11A of a wheel 11 and a ventilation port 19 to forcibly cool it. Then, the air is exhausted from the exhaust port 20A of the partition plate 20.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cooling structure for an outer rotor type wheel-in direct drive motor which is incorporated in a wheel of an electric vehicle to directly drive the wheel.

[0002]

[Prior Art]

 In recent years, in order to improve power transmission efficiency and reduce vehicle weight, electric vehicles of recent years have been abolished by reducing the speed reducer, the differential gear, and the drive shaft. There is something to drive. This type of electric motor is called an outer rotor type wheel-in direct drive electric motor, and is disclosed in, for example, Japanese Patent Laid-Open No. 63-275427.

A conventional example of this type of electric motor will be described with reference to FIG. In FIG. 2, a wheel 1 has a tubular portion 1A that projects toward the vehicle body on the inner peripheral side thereof, and the tubular portion 1A is mounted on a vehicle body side portion of the outer periphery of a hollow shaft 2 attached to the vehicle body via a bearing 3. Be done. 4 is a tire. A stator 6 of an electric motor 5 is attached to a portion of the hollow shaft 2 on the side opposite to the vehicle body, and a rotor 8 is enclosed in a frame 7 projecting on the side opposite to the vehicle body of the wheel 1 so as to surround the outer periphery of the stator 6. It is provided. 6A is a stator winding. A lead wire (not shown) of the electric motor 5 passes through the hollow shaft 2 and is drawn out to the vehicle body side.

[0004]

[Problems to be solved by the device]

 As can be seen from FIG. 2, the conventional outer rotor type wheel-in direct drive electric motor 5 has a fully closed structure, and the inside of the electric motor 5 has not been actively cooled. Therefore, there are the following problems.

In order to improve the running performance of an electric vehicle, it is indispensable to reduce the weight of the entire wheel including the electric motor 5. However, since the internal cooling is not actively performed, the size of the electric motor 5 is reduced due to the temperature rise limitation. It had to be large and could not be lightened. Also, when the speed of the electric vehicle is low, such as when climbing a hill, the cooling effect is poor because there is little wind, so even though a large output is required when climbing a hill, the output of the electric motor is limited and the temperature rises. I had to try not to rise.

An object of the present invention is to provide a cooling structure for an electric motor for an electric vehicle, which solves the above-mentioned problems of the prior art.

[0007]

[Means for Solving the Problems]

 A cooling structure for an electric motor for an electric vehicle according to the present invention includes a hollow shaft mounted on the body of an electric vehicle, a bearing mounted on the inner circumference of the hollow shaft, and a bearing mounted on the inner circumference of the hollow shaft through the bearing. A wheel having a cylindrical portion, a stator of an electric motor provided on the outer periphery of the hollow shaft, an annular frame projecting from the wheel toward the vehicle body and surrounding the outer periphery of the stator, A rotor of an electric motor provided on the inner circumference of the frame, a partition plate provided on the hollow shaft for rotatably closing the vehicle body side opening of the frame, and an intake port provided on the hollow shaft. A cooling fan connected to the intake port via a flexible duct, a filter provided on the intake side of this fan, and a part of the outer circumference of the wheel on the side opposite the vehicle body from the part supported by bearings. Provided It is an feature that includes a gas inlet and an exhaust port provided in the partition plate.

[0008]

[Action]

 The cooling fan draws in air through the filter, and forcibly blows air inside the motor through the flexible duct, hollow shaft, wheel cylinder and vent to cool it. The cooled air goes out through the exhaust port of the partition plate.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows a cross-sectional structure of an outer rotor type wheel-in direct drive electric motor 15 for an electric vehicle. The wheel 11 has cylindrical portions 11A and 17 which are provided on the inner peripheral side and the outer peripheral side thereof so as to project toward the vehicle body. The outer peripheral cylinder portion 17 is a frame for the electric motor rotor 18. The inner cylinder portion 11A of the wheel 11 is rotatably supported on the inner circumference of a hollow shaft 12 attached to the vehicle body via a bearing 13, and is more anti-vehicle body than the bearing 13 on the outer periphery of the cylinder portion 11A. One or more vent holes 19 are provided in the side portion. In FIG. 1, 14 is a tire.

A stator 16 having a stator winding 16 A is provided on the outer periphery of the hollow shaft 12, and a rotor 18 is provided in a frame 17 of the wheel 11 so as to surround the outer periphery of the stator 16, and further the frame 17 An annular partition plate 20 is provided on the outer periphery of the hollow shaft 12 so as to rotatably close the opening 17A facing the vehicle body. The partition plate 20 is provided with one or a plurality of exhaust ports 20A, and a flexible duct 21 is connected to the exhaust ports 20A to guide it to a place where water and dust are hard to enter and fix it to the vehicle body. The stator 16 is provided with an air passage 16B in the axial direction.

A partition plate 22 is provided at the end of the hollow shaft 12 on the vehicle body side, and an intake port 12 A is provided in the partition plate 22. The filter 23 for air is provided in a place where water and dust are unlikely to enter in the vehicle body and is attached to the cooling fan 24, and this fan 24 is connected to the intake port 12A of the hollow shaft 12 by the flexible duct 25.

With the above configuration, when the electric motor 15 is operated, the rotor 18 rotates to directly drive the wheel. Then, by operating the fan 24, cooling air flows as indicated by an arrow 26, and the inside of the electric motor 15 is forcibly cooled. A leak prevention structure is used to prevent the cooling air from leaking during the process.

[0013]

[Effect of the device]

 According to the present invention, it is possible to force cooling by sending cooling air into the electric motor by the fan. Therefore, since the temperature rise is small, the electric motor can be made smaller and lighter, and the output of the electric motor can be maximized even when the electric vehicle is traveling at low speed such as when climbing a slope.

[Brief description of drawings]

FIG. 1 is a diagram showing a cooling structure of an electric motor for an electric vehicle according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a conventional electric motor for an electric vehicle.

[Explanation of Codes] 11 Wheel 11A Cylindrical Part 12 Hollow Shaft 12A Intake Port 13 Bearing 14 Tire 15 Electric Motor 16 Stator 16A Stator Winding 16B Ventilation Path 17 Rotor Frame 17A Opening 18 Rotor 19 Venting Port 20 Partition Plate 20A Exhaust port 21,25 Flexible duct 22 Partition plate 23 Filter 24 Cooling fan 26 Cooling air path

Claims (1)

[Scope of utility model registration request] 1. A hollow shaft mounted on the vehicle body of an electric vehicle, a bearing mounted on the inner circumference of the hollow shaft, and a wheel having a tubular portion supported on the inner circumference of the hollow shaft via the bearing. , A stator of an electric motor provided on the outer periphery of the hollow shaft, and the wheel protruding from the wheel toward the vehicle body,
An annular frame surrounding the outer circumference of the stator, a rotor of an electric motor provided on the inner circumference of the frame, and a partition plate provided on the hollow shaft to rotatably close the vehicle body side opening of the frame. An intake port provided on the hollow shaft, a cooling fan connected to the intake port via a flexible duct, a filter provided on the intake side of the fan, and a bearing on the outer circumference of the cylindrical portion of the wheel. A cooling structure for an electric motor for an electric vehicle, comprising: a ventilation port provided on a side opposite to a vehicle body with respect to a portion supported by the exhaust port; and an exhaust port provided on the partition plate.