JPH0556101B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to an electric motor equipped with a stator having a laminated core and a rotor provided at the center of the stator. This invention relates to an electric motor that is directly cooled.

Prior art In general, a stator is formed by stacking a large number of stator cores punched from electromagnetic mesh plates, inserting excitation windings into the stacked cores, and having an output shaft in the center of the stator. In motors with a rotor structure, copper loss and heat associated with copper loss are generated within the stator, so appropriate cooling means are provided. A configuration was adopted in which heat-absorbing cooling was performed by flowing air. However, depending on the air cooling means, since the specific heat of the air itself is small, the amount of heat absorbed is also small, and when the amount of ventilation is increased to compensate for this, there is a problem that noise is generated, causing noise. To solve this problem, if cooling is performed using a cooling liquid such as water or oil, the liquid has a large specific heat and can be cooled with a relatively small flow rate. However, in order to remove the heat generated from the motor with liquid, it is necessary to provide a liquid passage with an appropriate sealing structure in consideration of liquid leakage, and to flow the cooling liquid within this liquid passage. Become. In this case, the most direct method is to provide a jacket for the coolant passage around the stator of the motor to form the liquid passage; There is a joint wall,
Heat is transferred from the stator to the cooling water through this joint wall, which causes the inconvenience of insufficient cooling efficiency, and the arrangement of the jacket increases the external dimensions of the motor, and the additional cost required to manufacture the jacket increases the manufacturing cost of the motor. This has the disadvantage that it leads to

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an electric motor that is equipped with a direct cooling means using a cooling liquid with high heat removal efficiency and a strong liquid leakage prevention film without using a separate element such as the above-mentioned jacket. It is something to do.

That is, according to the present invention, in an electric motor including a stator having a laminated core and a rotor provided at the center of the stator, the laminated core of the stator is one of the laminated cores. A plurality of cores are laminated in the axial direction, and a through hole with an uneven groove is provided in the peripheral area of the laminated core. The inner periphery of the through hole of the stator is filled with resin to form a liquid leakage prevention film to provide a coolant passageway for smooth road surfaces, and the stator is directly cooled by the coolant flowing through the liquid passageway. There is provided an electric motor characterized in that the hole dimensions of the holes in the stator laminated core are preformed in different sizes for each core, and the stator through holes are formed into uneven holes. By providing a leakage prevention film made of a resin material therein, the formation of the leakage prevention film is facilitated and the leakage prevention effect is ensured. Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

FIG. 1 is a partially cutaway front view showing an embodiment of the electric motor of the present invention. In the figure, the electric motor has a stator 10, and this stator 10 is made up of a number of laminated stator cores. The core part 12 and the core part 1
2, an excitation winding 14 inserted inside the
Front housing 1 is located before and after this stator 10.
6 rear housing 18 is fixedly installed, and rotary bearings 20 and 22 are held coaxially within both housings 16 and 18. And this double rotation bearing 2
A rotor 26 is attached to the output shaft 24 supported by the stator 10, and at this time, the rotor 26 is located at the center of the stator 10, and the two interact electromagnetically to generate a rotational output to the rotor 26. It has a structure in which the rotational output is taken out from the output shaft 24.
Furthermore, various elements for controlling the rotation of the electric motor are incorporated within the rear housing 18.

Now, according to the invention, the front housing 1
A cooling fluid inlet 28 formed in a part of the rear housing 18 passes through a liquid passage 30 extending in the axial direction on the peripheral edge of the stator 10 , and a cooling fluid outlet 32 formed in a part of the rear housing 18 A flow path for the coolant to be discharged is formed. The flow of the coolant can be achieved by applying fluidity to the coolant using a liquid pump means provided separately from the electric motor. Also,
The number of liquid passages 31 formed at the periphery of the core portion 12 of the stator 10 described above is not one, but a plurality are provided around the core portion 12, and the front housing 16
The cooling fluid flowing into the front housing 16 from the cooling fluid inlet 28 enters the front housing 16 through the cooling fluid inlet 28.
The cooling fluid flows into the plurality of liquid passages 30 through the cooling fluid chamber provided directly connected to the cooling fluid chamber 8, and the cooling liquid flowing out from the plurality of liquid passages 30 flows into the cooling fluid outlet 32 of the rear housing 18. A configuration is adopted in which the cooling fluid collects in a cooling fluid chamber that is directly connected to the cooling fluid chamber, and then flows out from the cooling fluid outlet 32. When the above-mentioned coolant flow configuration is adopted, the heat generated in the excitation winding 14 and the core section 12 during operation of the motor is directly removed after cooling through the liquid passage 30 of the core section 12. Subjected to thermal effects. Therefore, an efficient direct-cooled, liquid-cooled motor is constructed. Note that a leakage prevention film 34 is applied to the inner periphery of the liquid passage 30 of the core portion 12 in advance during the manufacturing stage of the stator 10 of the electric motor to prevent liquid from leaking through the laminated slits between the laminated cores. There is. The easiest way to provide this liquid leakage prevention film 34 is to coat the liquid passage 30 with resin coating.
A resin film may be formed all around the inner wall.

FIG. 2 is an enlarged cross-sectional view of a part of the flow path 30, which shows that the inside of the liquid path 30 is formed into an uneven path in the axial direction, and a leakage prevention coating 34 is formed in each groove portion of the liquid path 30.
The figure shows that the structure is filled with resin that forms the . When such a structure is provided, the resin layer filled in each of the grooves firmly holds the leakage prevention coating 34, which is extremely advantageous in extending the service life.

FIG. 3 is a cross-sectional view taken along the - line in FIG. 1 to show the planar shape of each stator core forming the core portion 12 in the stator 10 of the electric motor shown in FIG. As shown at the same time, stator core 12
In a, deep groove-shaped holes into which excitation windings 14 are inserted are arranged in a row at equal intervals on the circumference in the center, and a large number of holes 36 of different shapes as appropriate are bored in the periphery. .
The insertion hole for the excitation winding 14 and the perforation hole 36 are all formed by punching out a band-shaped or thin plate-shaped electromagnetic steel plate using a die. Now, the above-mentioned perforation hole 36 is a hole that forms the above-mentioned liquid passage 30 when a large number of stator cores are stacked, and the excitation winding 1
The holes are formed by effectively utilizing the areas of the four corners surrounding the insertion groove No. 4. In other words, the coolant passage is formed by effectively utilizing the portion of the electromagnetic steel sheet material that would normally be cut away. In addition, in order to form the above-mentioned uneven liquid passage 30, two types of holes having substantially similar hole shapes but different sizes are used at the stage of forming the perforated holes 36 in each stator core 12a by punching. If the fixing hole core 12a is formed in advance and the two types of stator cores are alternately stacked when forming the core part 12 by laminating them, the liquid passage 30 having an uneven shape can be naturally formed.

Effects of the Invention As is clear from the above description, according to the present invention, since the stator, which forms the heat generating part of the electric motor, is directly cooled using the cooling liquid, it is possible to obtain an electric motor with extremely good cooling efficiency. . In addition, the cooling fluid leakage prevention film in the cooling passage has a long service life because the resin layer is firmly held by the unevenness formed on the laminated core, and the cooling performance of the motor can be maintained at a high level over a long period of time. It is played.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing the structure of an embodiment of the electric motor according to the present invention, FIG. 2 is an enlarged sectional view of section A in FIG. 1, and FIG. 3 is a line taken along the line - A cross-sectional view along. 10... Stator, 12... Core portion, 14... Excitation winding, 16... Front housing, 18...
Rear housing, 24...Output shaft, 26...Rotor, 30...Liquid passage, 36...Drilled hole.

Claims (1)

[Scope of Claims] 1. In an electric motor equipped with a stator having a laminated core and a rotor provided at the center of the stator, each laminated core of the stator has a A plurality of cores are laminated in the axial direction, and a through hole having a groove is provided in the peripheral area of the laminated core, and a through hole with a groove is provided in the peripheral area of the laminated core. The inner periphery of the through hole of the stator is filled with resin to provide a liquid leakage prevention film to provide a coolant passageway for smooth road surfaces, and the stator is directly cooled by the coolant flowing through the liquid passageway. An electric motor characterized by: 2. The electric motor according to claim 1, wherein the laminated core of the stator has a rectangular shape and has the through hole at each corner thereof.