JPH04224490A - Motor cooling structure of motor-driven vehicle - Google Patents

Abstract

PURPOSE:To make a cooling device for a motor, which is used as a drive motive for a car, small, light, and powerless, and prevent intrusion of water and mud by sealing a motor housing. CONSTITUTION:At the periphery of a housing 17 for a motor M provided for driving a car, a liquid sump 172 is formed in which a refrigerant such as liquid fron is encapsulated. With this liquid sump 17, a condenser 14 is connected which is equipped with a heat pipe 50 consisting of a metal pipe 54 capable of retaining the refrigerant. Accordingly the motor M is cooled by the gasification heat due to refrigerant gasifying in the liquid sump 172, and the vapor of refrigerant gasified is liquefied back by the heat pipe 50 of the condenser 14 to be returned to the liquid sump 172.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle using an electric motor as a driving power source, and more particularly to a structure for cooling the motor.

0002

[Prior Art] Conventionally, an internal combustion engine has generally been used as a driving power source for vehicles such as motorcycles, but instead of this internal combustion engine, motorcycles using electric motors as a power source have been proposed (for example, , see Utility Model Application Publication No. 51-80848). Using an electric motor as the power source for a vehicle not only solves the problem of exhaust gas and is advantageous for use in special environments such as indoors, but also allows for use in air cleaners, carburetors, etc.
Since accessories such as a muffler, fuel tank, and starting device can be omitted, a vehicle with a simple structure and excellent handling properties can be obtained.

0003

[Problem to be Solved by the Invention] By the way, in a motorcycle powered by such an electric motor, if a water cooling system similar to that of an internal combustion engine is adopted as the cooling method for the electric motor, a radiator and a cooling water pump are required. There is a problem that the weight increases. It is also possible to make the electric motor air-cooled, but this would not only result in insufficient cooling effect, but would also require an opening to introduce cooling air into the electric motor housing. Water, mud, etc. may enter through this opening.

The present invention has been made in view of the above-mentioned circumstances, and it is possible to efficiently cool a motor as a power source of a vehicle with a simple and lightweight structure. An object of the present invention is to provide a motor cooling structure for an electric vehicle that is free from the risk of mud infiltration.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the motor cooling structure for an electric vehicle of the present invention is an electric vehicle that runs by driving drive wheels with a motor, in which a refrigerant is sealed in the housing of the motor. A condenser equipped with a heat pipe made of a metal tube capable of holding the refrigerant is connected to this liquid reservoir.

[0006]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

1 to 4 show a first embodiment of the present invention. FIG. 1 is an overall side view of a motorcycle to which the motor cooling structure is applied, and FIG. 2 is a sectional view taken along line 2-2 in FIG. , FIG. 3 is a sectional view taken along the line 3-3 in FIG. 2, and FIG. 4 is an enlarged view of the condenser shown in FIG.

As shown in FIG. 1, the body frame F of the motorcycle V is composed of a front frame F1, a center frame F2, and a rear frame F3 made of steel pipes.
Outside of that is leg shield B1, step floor B2
, a rear cover B3, and an undercover B4. A head pipe 1 fixed to a front frame F1 has a steering handle 2 at its upper end and a front fork 4 having a front wheel Wf pivoted thereon via a front cushion 3 at its lower end. At the rear of the central frame F2 is a swing-type power unit P with the rear wheel Wr mounted on the rear end.
The front end of the power unit P is supported by a pivot 5 so as to be vertically swingable, and the rear upper surface of the power unit P and the rear frame F3 are connected via a rear cushion 6. Central frame F2
A stand 7 provided in the figure covers the lower front surface of the power unit P in the illustrated storage position, and also serves as a protection member for a motor M, which will be described later, housed therein. A storage compartment 9 is provided between the power unit P and the seat 8 for storing a helmet and the like. This container 9 is made of a material that shields magnetism, such as conductive resin, so that stored items such as floppy disks are not affected by the magnetism generated by the motor. A battery box 10 for storing a battery as a power source for driving the motor M is provided in the central frame F2. Further, in front of the head pipe 1, a controller 11 for controlling the drive of the motor M and a charger 12 for charging the battery are provided. Furthermore, inside the rear cover B3, there is an air guide port 13 opened on the left side of the rear cover B3.
A condenser 14 for cooling the motor is disposed at the rear of the motor.

Next, the structure of the power unit P will be explained in detail based on FIG. 2. The power unit P is equipped with a transmission case 15 at the front end through which the pivot 5 penetrates from side to side, and a motor M provided at the front and a reducer 16 provided at the rear.
are connected via a belt-type continuously variable transmission B.

The right end opening of the motor housing 17 housing the motor M therein is closed by a lid member 18 fixed with bolts, and a mounting flange 171 formed on the left side thereof.
is attached to a reinforcing flange 151 formed around the opening of the transmission case 15 with bolts. The rotating shaft 19 of the motor M is connected to a ball bearing 20 provided on the lid member 18.
and is supported by a ball bearing 21 provided on the left end wall of the motor housing 17.

The motor M is a DC brushless motor, and has a permanent magnet 23 on the outer periphery of an iron core 22 fixed to a rotating shaft 19.
A coil 2 is wound around an iron core 25 fixed to the inside of the motor housing 17 with bolts.
6, and a rotor position sensor 28 for detecting the phase of the rotor 24 is provided at the right end of the rotating shaft 19.

The belt-type continuously variable transmission B housed inside the transmission case 15 has a drive pulley 29 provided on a rotating shaft 19 protruding into the transmission case 15 from the motor housing 17 side, and a drive pulley 29 provided at the rear of the transmission case 15. A driven pulley 31 provided on the supported reducer input shaft 30, both pulleys 29,
An endless belt 32 is wound around the belt 31. The drive pulley 29 is a stationary pulley half 291 fixed to the rotating shaft 19.
The movable pulley half 292 is supported by the rotary shaft 19 so as to be slidable in the axial direction, and the movable pulley half 292 and the lamp plate 33 are fixed to the rotary shaft 19.
A centrifugal weight 34 is disposed between the two and is movable in the radial direction. On the other hand, the driven pulley 31 consists of a fixed pulley half 311 and a movable pulley half 312 supported by a collar 36 that is relatively rotatably fitted to the reducer input shaft 30 via a needle bearing 35. 3
1 is transmitted to the reduction gear input shaft 30 via an automatic centrifugal clutch 37. The left side surface of the transmission case 15 housing the belt type continuously variable transmission B and the automatic centrifugal clutch 37 is closed by a detachable side cover 38.

The reducer input shaft 30 is supported by a ball bearing 39 provided in the transmission case 15 and a ball bearing 41 provided in the reducer cover 40, and is supported by a pair of balls also provided in the transmission case 15 and the reducer cover 40. Axle 4 of rear wheel Wr supported by bearings 42, 43
An intermediate shaft 45 is supported between the shaft 4 and the shaft 4. The rotation of the input gear 46 of the reducer input shaft 30 is transmitted to the output gear 49 of the axle 44 via the two intermediate gears 47 and 48 of the intermediate shaft 45.

As shown in FIGS. 2 and 3, an annular liquid reservoir 172 is formed in the motor housing 17 that covers the motor M so as to surround the outer periphery of the stator 27.
A refrigerant such as liquid fluorocarbon is stored in a sealed state inside the refrigerant 72 . The upper part of the liquid reservoir 172 is formed to have a large cross-sectional area, and the condenser 1 is installed at the top of the upper part of the liquid reservoir 172.
A joint portion 501 provided at the base end side of the heat pipe 50 constituting the heat pipe 4 is fixed.

As is clear from FIG. 4,
The tips of the heat pipes 50 are alternately bent to form a triangular shape when viewed from the side, and the tips are closed with plugs 51. The heat pipe 5 bent into the triangular shape
The outer periphery of 0 is held by a frame 52 having a U-shaped cross section, and the condenser 14 made up of the heat pipe 50 and the frame 52 is attached to a bracket 15 protruding from the upper part of the transmission case 15.
2 via bolts 53. In order to make the running wind act on this condenser 14, the rear cover B3
The air guide port 13 is formed on the left side surface (see FIG. 1).
.

As shown in FIG. 3, the heat pipe 50 has a structure in which the inner surface of a metal tube 54 is lined with a porous wick 55 in which the refrigerant permeates and is retained. After the inside of the tank is once evacuated, the liquid reservoir 172 is filled with refrigerant.

Next, the operation of the first embodiment of the present invention having the above-described configuration will be explained. When the rotation speed of the motor M is low, the automatic centrifugal clutch 37 is in a disengaged state, and the driving force of the motor M is not transmitted to the rear wheels Wr. When the rotational speed of the motor M is increased from this state, the automatic centrifugal clutch 37 is eventually engaged and the driving force of the motor M is transmitted to the rear wheel Wr. When the rotational speed of the motor M further increases, the centrifugal weight 34 moves radially outward along the ramp plate 33 fixed to the rotation shaft 19 of the motor M, and moves the movable pulley half 292 of the drive pulley 29 to the fixed pulley. It is moved in a direction approaching the half body 291. As a result, the effective radius of the drive pulley 29 increases, and at the same time, the movable pulley half 31 of the driven pulley 31
2 is driven in a direction away from the stationary pulley half 311, and its effective radius decreases. As a result, the reduction ratio of the belt-type continuously variable transmission B decreases, the rotational speed of the rear wheels Wr increases, and the vehicle is accelerated.

The motor M generates heat as it rotates, and in particular, in a brushless motor, a stator 27 having a coil 26
Since the amount of heat generated on the side is large, the temperature of the motor housing 17 that supports the stator 27 increases significantly. When the temperature of the motor housing 17 rises in this way, the refrigerant stored in the sealed liquid reservoir 172 vaporizes, and at this time, the motor M is cooled by removing heat from the motor housing 17. The vapor of the vaporized refrigerant rises inside the heat pipe 50 from the liquid reservoir 172;
Since the condenser 14 constituted by the refrigerant is kept at a low temperature by the running wind, the refrigerant vapor is liquefied again and adheres to the wick 55 on the inner surface of the heat pipe 50. The refrigerant thus liquefied descends by gravity along the wick 55 and returns to the liquid reservoir 17 formed in the motor housing 17.
will be returned to.

Therefore, the liquid reservoir 17 of the motor housing 17
By repeating the vaporization of the refrigerant in Step 2 and the liquefaction of the refrigerant in the heat pipe 50 of the condenser 14, the motor M that generates heat is effectively cooled. Furthermore, since there is no need to provide the motor housing 17 with an opening that communicates with the atmosphere, there is no inconvenience that water or mud may enter the inside of the motor M.

5 to 7 show a second embodiment of the present invention, FIG. 5 is an overall side view of a motorcycle to which the motor cooling structure is applied, and FIG. 6 is a sectional view taken along line 6-6 in FIG. , FIG. 7 is a 7-direction arrow view of FIG.

As shown in FIG. 5, the body frame F of this motorcycle V includes a head pipe F4 and a pair of left and right main frames F5, and these left and right main frames F5 are interconnected by a plurality of cross members (not shown). be combined. Front fork 6 supported by head pipe F4
A front wheel Wf is pivotally supported at the lower end of the vehicle 1, and a steering handle 62 is provided at the upper end thereof. A box 63 housing a controller for a motor M, which will be described later, etc., is mounted on the main frame F5, and a seat 65 is supported on the top of a seat frame 64 extending rearward from below the box 63. At the rear end of the main frame F5, the front end of a swing arm 66 is supported by a pivot 67 so as to be able to swing up and down, and the rear wheel Wr is pivotally supported at the rear end of the swing arm 66.

A power unit P including a motor M and a transmission 70 is supported by a pair of front and rear brackets 68 and 69 fixed to the lower part of the main frame F5. A cage-like battery frame 74 is suspended from brackets 71, 72, and 73 provided at the lower ends of the motor M, the transmission 70, and the main frame F5, and a battery 75 as a power source for driving the motor M is installed inside the cage-like battery frame 74. Supported. Drive sprocket 76 provided on the output shaft of the mission 70
The driven sprocket 77 provided on the rear wheel Wr is a chain 78.
The driving force of the motor M is thereby transmitted to the rear wheel Wr. Further, the vehicle body frame F is provided with a cowling C that covers the power unit P, the battery 75, etc., and a condenser 79 for cooling the motor M is provided so as to face an opening formed at the upper end of the front part of the cowling C. .

As shown in FIG. 6, the power unit P includes a mission case 80 that houses the mission 70,
and a motor housing 81 connected to the front part thereof,
The left and right sides of the mission case 80 are covered by a left cover 82 and a right cover 83, and the left side of the motor housing 81 is covered by a cover member 84.

The motor M is the same DC brushless motor as in the previous embodiment, and includes a stator 85 provided on the motor housing 81 side and a rotor 89 provided on a rotating shaft 88 supported by a pair of ball bearings 86 and 87. Equipped with A ball bearing 9 is installed in the mission case 80 and the left cover 82.
0 and the main shaft 92 via the roller bearing 91
is supported by a driven gear 94 provided on the outer periphery of a wet multi-disc clutch 93 provided at the right end of the main shaft 92, and a driving gear 95 provided at the right end of the rotating shaft 88 of the motor M.
mesh together. A counter shaft 98 is connected to the rear of the main shaft 92 via a pair of ball bearings 96 and 97.
is supported, and the main shaft 92 and the counter shaft 9
8, a plurality of gear trains G1 to G6 are arranged for selectively establishing a desired gear stage. A drive sprocket 76, around which the chain 78 is wound, is fixed to the left end of the countershaft 98.

An annular liquid reservoir 811 in which a refrigerant is sealed is formed on the outer periphery of the motor housing 81.
A joint portion 501 that connects to the heat pipe 50 constituting the condenser 79 is connected to the upper end of the condenser 1 .

The condenser 79 has a large number of heat pipes 5 between a pair of square pipes 99 and 100 arranged vertically.
0 are joined by brazing in the left and right direction, and a large number of cooling fins 101 made of thin metal plates are brazed to connect the upper and lower heat pipes 50, and a rectangular frame 102 that holds the outer periphery of the The left and right upper ends are fixed with bolts 104 to brackets 103 provided on the main frame F5. The plurality of heat pipes 50 are inclined at an angle θ with respect to the horizontal line so that one end is slightly lower than the other end, and the lower end of the square pipe 99 connected to the lower side of the heat pipe 50 is connected to a liquid reservoir 811 of the motor housing 81 via a joint portion 501. Note that the cooling fins 101 can also be provided independently for each heat pipe 50.

According to this embodiment, when the driving force of the motor M is transmitted to the main shaft 92 of the transmission 70 via the clutch 93, its rotation is transmitted to the main shaft 92 of the transmission 70.
1 to G6 and is transmitted to the countershaft 98, and further transmitted to the rear wheel Wr via the drive sprocket 76, chain 78, and driven sprocket 77.

The motor M that generates heat during operation is removed from the liquid reservoir 812 formed in the motor housing 81 as in the previous embodiment.
It is cooled by the heat of vaporization when the internal refrigerant evaporates. Then, the vaporized refrigerant is removed with heat inside the heat pipe 50 constituting the condenser 79 and becomes liquefied again, passes through the wick 55 on the inner surface of the heat pipe 50 provided at an angle, and collects in the square pipe 99. , and is further returned to the liquid reservoir 811 via the joint part 501.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various small designs can be made without departing from the scope of the invention described in the claims. It is possible to make changes.

For example, the refrigerant is not limited to chlorofluorocarbon, and water or alcohol can be used. Further, the cooling structure of the present invention is applicable not only to the motor of a motorcycle, but also to the cooling of the motor of other vehicles such as a four-wheeled vehicle.

[0031]

As described above, according to the present invention, a liquid reservoir containing refrigerant is formed in the motor housing, and a condenser having a heat pipe is connected to this liquid reservoir. The motor is cooled by the heat of vaporization when the refrigerant vaporizes, and the vaporized refrigerant is liquefied again in the condenser and returned to the liquid reservoir. Therefore, the large radiator and cooling water pump that are required when adopting a water-cooled cooling structure are not required, which not only makes it possible to reduce weight, but also enables efficient cooling of the motor without power. . Further, since there is no need for a ventilation opening in the motor housing which is required when an air-cooled cooling structure is adopted, there is no risk of water, mud, etc. entering the inside of the motor housing.

[Brief explanation of the drawing]

[Fig. 1] Overall side view of a motorcycle according to a first embodiment of the present invention.

[Figure 2] Cross-sectional view taken along line 2-2 in Figure 1

[Figure 3] Cross-sectional view taken along line 3-3 in Figure 2

[Figure 4] Enlarged view of main parts of Figure 1

[Fig. 5] Overall side view of a motorcycle according to a second embodiment of the present invention.

[Figure 6] Cross-sectional view taken along line 6-6 in Figure 5

[Figure 7] View from the 7-direction arrow in Figure 5

[Explanation of symbols]

14 Condenser 17 Motor housing (housing) 172
Liquid reservoir 50 Heat pipe 54 Metal tube 79 Condenser 81 Motor housing (housing) 811
Liquid reservoir M Motor Wr Rear wheel (drive wheel)

Claims (1)

[Claims] Claim 1: In an electric vehicle that runs by driving drive wheels (Wr) with a motor (M), a liquid reservoir (172) containing a refrigerant is provided in a housing (17, 81) of the motor (M).
, 811 ), and this liquid reservoir ( 172 , 811 ) is formed.
) is connected to a condenser (14, 79) equipped with a heat pipe (50) made of a metal tube (54) capable of holding the refrigerant.