JPH0946972A - Motor for electric car and its cooling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact motor for an electric vehicle by providing a first water passage formed in a power box, a second water passage formed in a stator, and a third water passage directly communicating with the first and second waterways formed to an end plate. SOLUTION: A cooling water passage 10c formed in a power head 10 comprises a power part cooling water passage 101c for cooling a switching element 7 and a communication water passage 102c of an end plate portion 10b, and the communicating waterway 102c communicates a cooling water passage 3a formed in the power cooling water passage 101c and a stator 3. Also, a cooling water passage 3a and a cooling water passage 3b of the stator 3 communicate with each other through a communication water passage 11a formed in the end plate 11. And a cooling solution flowed from an intake 10e of the cooling solution to the power cooling water passage 101c cools the switching element 7 and then flows into the cooling water passage 3a of the stator 3 through the communication water passage 102c. As a result, no pipe fittings are required for interconnecting the water passages, thereby decreasing the size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle motor with improved cooling performance.

[0002]

2. Description of the Related Art Conventionally, in a motor for an electric vehicle, in order to prevent the insulating coating covering the winding from deteriorating or burning due to heat generation of the coil, cooling water is supplied to cool each part of the motor. There is. FIG. 4 is a cross-sectional view in which the cooling jacket 1 for cooling the motor is mounted on the stator 3 of the motor 2. The cooling jacket 1 comprises a cooling water passage 1a and a box portion 1b, and is integrally manufactured by aluminum casting or the like. A switching element 7 such as an IGBT (Insulated Gate Bipolar Transistor) that constitutes a control circuit of the motor 2 is attached to the box portion 1b. Reference numeral 4 is an end plate attached to both ends of the stator 3, and a rotor 6 is rotatably supported by a bearing 5 provided on the end plate 4.

By the way, the life of the IGBT used for the switching element 7 is greatly influenced by the temperature change. In particular, the junction portion, which is the joint portion between the chip and the bonding wire inside the IGBT, has a shorter life as the temperature change is larger, and it is necessary to keep the junction temperature at about 70 ° C. Therefore, the cooling water is introduced into the cooling water passage 1a from the intake port (not shown), and is discharged from the discharge port (not shown) after passing through the cooling water passage 1a, whereby the stator 3 is cooled and attached to the box portion 1b. The switching element 7 thus cooled is also cooled at the same time.

[0004]

However, in the above-mentioned conventional motor, since the cooling jacket 1 is mounted on the outer peripheral portion of the stator 3, the size and weight of the motor increase, which is an obstacle to miniaturization of the motor. . Further, since the stator 3 is cooled via the member of the motor housing portion 1a, the cooling efficiency is low, which is also an obstacle to downsizing of the motor. On the other hand, there is a conventional motor that cools the stator by providing a copper pipe or the like for cooling inside the stator, but in this case, a pipe that connects the cooling pipe of the stator and the cooling water passage of the switching element is required. Therefore,
There are drawbacks such as an increase in water flow resistance due to the piping, occurrence of water leakage from the piping connection portion due to vibration at the time of driving the motor, and an increase in cost associated with the piping.

An object of the present invention is to provide a motor for a compact electric vehicle, which is equipped with a cooling device for simultaneously cooling the switching element and the motor.

[0006]

1 and 2, showing an embodiment of the present invention, the invention of claim 1 relates to a stator 3 and a rotor which is rotated by a rotating magnetic field generated in the stator 3. 6, a pair of end plates 10b and 11 that rotatably support the rotor 6, and a power box 1 to which a switching element 7 for motor control is attached.
0a, a first water channel 101c formed in the power box 10a for cooling the switching element 7 and second water channels 3a to 3d formed in the stator 3 for cooling the stator 3 And the first and second water channels 101 formed in the end plate 10b.
The first water channel 101 directly communicating with each of c and 3a.
The above-described object is achieved by including the third water channel 102c that connects the second water channel 3a with the second water channel 3a. In the electric vehicle motor according to the invention of claim 2, the power box 10a and the end plate 10b in which the third water passage 102c is formed are integrally provided. A method for cooling an electric vehicle motor according to a third aspect of the present invention is the electric vehicle motor according to the first or second aspect, wherein the cooling liquid that has passed through the first water channel 101c is introduced into the second water channels 3a to 3d. The cooling element cools the switching element 7 on the upstream side and the stator 3 cools on the downstream side.

In the electric vehicle motor according to the first and second aspects of the invention, the first water passage 101c and the second water passages 3a to 3d are communicated with each other by the third water passage 102c which is an internal water passage in the end plate 10b. , They form a channel, through which the cooling liquid flows. In the electric vehicle motor according to the second aspect of the invention, the power box 10a and the end plate 10b are integrated to reduce the man-hours for assembling the motor and simplify the assembly. According to the invention of claim 3, the cooling liquid is the first water channel 101c and the third water channel 102c.
And the second water channels 3a to 3d flow in this order, the switching element 7 is cooled first, and its cooling effect is good.

In the meantime, in the section of the means for solving the above-mentioned problems which explains the constitution of the present invention, the drawings of the embodiments of the present invention are used to make the present invention easy to understand, but the present invention However, the present invention is not limited to the embodiment.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1A and 1B are schematic configuration diagrams of a motor for an electric vehicle according to the present invention. FIG. 1A is a sectional view of the motor, and FIG. 1, the same parts as those in FIG. 4 are designated by the same reference numerals. Reference numeral 10 denotes a power head. The power head 10 is attached to a power box portion 10a in which a switching element 7 constituting a motor control circuit is housed and a front end surface of a stator 3 to support a front side of a rotor 6. The end plate portion 10b is integrally formed into a substantially L shape. The cooling water channel 10c formed in the power head 10 is
Power part cooling water channel 101c for cooling the switching element 7 and communication water channel 102c for the end plate portion 10b
And the connecting water channel 102c is the power section cooling water channel 10
1c and the cooling water channel 3a formed in the stator 3 are connected. On the other hand, an end plate 11 is attached to the rear end surface of the stator 3 to support the rear side of the rotor 6. Reference numeral 11a denotes a connecting water passage formed in the end plate 11, and the cooling water passage 3a and the cooling water passage 3b of the stator 3 communicate with each other via the connecting water passage 11a. The end plate portion 10b and the end plate 11 are attached to the stator 3 with bolts 12. Reference numeral 10e denotes a cooling liquid intake port, and the cooling liquid that has flowed into the power section cooling water passage 101c from the intake port 10e cools the switching element 7 and then flows into the cooling water passage 3a of the stator 3 through the connecting water passage 102c. The arrows in the figure show the flow of the cooling liquid, and the same applies to the following figures.

FIG. 2 is a view showing a cross section perpendicular to the rotor rotation axis of the motor. (A) is a cross section of the end plate 11 portion, (b) is a cross section of the stator 3 portion, and (c) is the end plate. It is the figure which looked at the cross section of the part 10b part, respectively from the rear side of a motor. Note that parts not related to the description are omitted. In the stator 3, cooling water passages 3a, 3b, 3c and 3d are formed in the rotor rotation axis direction, and the cooling water passages 3a to 3d are each composed of three water passages. Power section cooling water channel 101 shown in FIG.
The cooling liquid that has passed through c flows into each of the three water channels of the cooling water channel 3a of the stator 3 via the communication water channel 102c. The cooling liquid that has passed through the cooling water passage 3a is the end plate 1
It flows into the cooling water passage 3b through the first connecting water passage 11a.
Similarly, the cooling liquid that has passed through the cooling water passage 3b passes through the communication water passage 10g, the cooling water passage 3c, the communication water passage 11b, and the cooling water passage 3d, respectively, and then flows into the communication water passage 10h.
It is discharged from a discharge port 10f provided in the end plate portion 10b.

In the stator 3 formed by stacking plates, the cooling water passages 3a to 3d are sprayed with epoxy paint or the gap between the plates is vacuum impregnated with epoxy resin or the like to waterproof the cooling water passages 3a to 3d. Processing is performed. Further, as shown in FIG. 1B, after the liquid packing is applied to the surface 31 where the end plate 11 contacts the stator 3, the end plate 11 is attached to the stator 3 to form a face seal. A liquid packing 32 is also provided between the stator 3 and the stator 3 to waterproof the joint between the end plate 11 and the stator 3. The waterproofing process for the joint between the end plate 10b and the stator 3 is also performed in the same manner.

By the way, since the switching element 7 is easily affected by the temperature change, as described above, the power section cooling water channel 101c is provided on the upstream side of the cooling water channel system, and the switching element 7 attached to the power box section 10a is the stator. It is made to be hardly affected by the temperature of 3.

In the embodiment of the invention described above, since the end plate portion 10b is attached to the front end surface of the stator 3 to directly communicate the cooling water passage 3a and the communication water passage 102c, the communication water passage 102c and the cooling water passage 3a are connected. It does not require pipes to connect with, and keeps water resistance low. Further, since the cooling water passages 3a to 3d are formed in the stator 3 to cool the stator 3, it is possible to improve the stator cooling performance and reduce the size and weight of the motor. Furthermore, since the power part cooling water channel 101c for cooling the switching element 7 is provided upstream of the cooling water channel system,
The switching element 7 is not affected by the heat generation of the motor.
Can be cooled.

FIG. 3 is a modification of the motor shown in FIGS. 1 and 2, and (a) to (c) are sectional views similar to FIGS. 2 (a) to 2 (c), respectively. In the example shown in FIG.
Each of the cooling water channels 3a to 3d was a tubular cooling water channel, but in the case of FIG. 3, after forming axial grooves on the four outer peripheral surfaces of the stator 3, a plate 22 that covers each groove is attached by welding or the like to cool. The water channels 23a to 23d are formed. Other configurations are the same as those in FIG. The cooling liquid that has flowed from the power section cooling water channel 101c (not shown) into the communication water channel 102c is cooled water channel 23a, communication water channel 11a, cooling water channel 23b, communication water channel 10g, cooling water channel 23c, communication water channel 1.
1b, cooling water passage 23d, and communication water passage 10h, respectively, and an outlet 1 provided in the end plate portion 10b.
It is discharged from 0f.

In the embodiment of the invention described above, the power box portion 10a and the end plate portion 10b are integrally provided, but they may be provided separately and connected to each other by a fastener such as a bolt. Further, although the end plate portion 10b of the power head 10 is provided on the front side of the stator 3, on the contrary, the end plate portion may be provided on the rear side and a separate end plate may be attached to the front side. Good.

In the correspondence between the embodiment of the invention described above and the claims, the power section cooling water channel 101c is the first water channel, the cooling water channels 3a to 3d are the second water channels, and the connecting water channel 102c is the first water channel. 3 of the water channel, the end plate portion 10
b and the end plate 11 constitute an end plate, and the power box portion 10a constitutes a power box.

[0017]

As described above, according to the present invention,
Since the third water channel formed in the end plate is in direct communication with each of the first water channel and the second water channel,
Piping is not required for connecting the first water channel and the second water channel and for connecting the second water channel and the third water channel, thereby reducing manufacturing cost and downsizing, and keeping water resistance low. It is possible to improve the cooling performance. Particularly, in the invention of claim 2, since the power box and the end plate having the third water channel are integrated, the number of assembling steps can be reduced. Further, in the invention of claim 3, since the cooling liquid flows into the third water passage formed in the stator after passing through the first water passage for cooling the switching element,
The switching element 7 is not affected by the heat generation of the motor.
Can be cooled.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a motor for an electric vehicle of the present invention, (a) is a sectional view of the motor, and (b) is a detailed view of a portion A of (a).

2 is a cross-sectional view of the motor of FIG. 1, in which (a) shows an end plate 11 portion, (b) shows a stator 3 portion, and (c) shows an end plate portion 10b portion, respectively.

3 is a cross-sectional view showing a modified example of the motor of FIG.
(A) is the end plate 11 part, (b) is the stator 3
Part (c) shows each of the end plate parts 10b.

FIG. 4 is a cross-sectional view of a conventional electric vehicle motor.

[Explanation of symbols]

 3 Stator 3a-3d, 10c, 23a-23d Cooling water channel 6 Rotor 7 Switching element 10 Power head 10a Power box part 10b End plate part 10g, 10h, 11a, 11b, 102c Connecting water channel 101c Power part cooling water channel

Claims (3)

[Claims] 1. A stator, a rotor that rotates by a rotating magnetic field generated in the stator, a pair of end plates that rotatably support the rotor, and a power box to which a switching element for controlling a motor is attached. In an electric vehicle motor, a first water channel formed in the power box for cooling the switching element, and a second water channel formed in the stator for cooling the stator
And a third water channel that is formed in either one of the end plate and directly communicates with each of the first and second water channels to communicate between the first water channel and the second water channel. A motor for an electric vehicle, comprising: 2. The electric vehicle motor according to claim 1, wherein the power box and the end plate in which the third water channel is formed are integrally provided. 3. The method for cooling an electric vehicle motor according to claim 1, wherein the cooling liquid that has passed through the first water channel is introduced into the second water channel, and the switching is performed on the upstream side of the cooling liquid. A method for cooling an electric vehicle motor, comprising cooling the element and cooling the stator on the downstream side.