JPH08140310A - Open type induction motor - Google Patents

Abstract

(57) [Abstract] [Purpose] By providing a gap between the stator and the bracket, the outer circumference of the stator is cooled and the electric motor can be downsized. [Structure] In an open-type electric motor without a frame, air holes are provided at positions on the outer peripheral surface of the bracket that face the arcs of the stator, and no air holes are provided at positions that face the chords of the stator, leaving a gap in the outer diameter of the stator. The feature is to increase the outer diameter of the bracket as much as possible. By changing the air flow direction by the gap between the stator and the bracket, the electric motor can be made smaller and lighter than conventional products.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an open-ended induction motor having a simple structure and reduced size and weight, and more particularly to the structure of an open-ended induction motor in which the outer circumference of the stator of the motor is exposed to the outside. is there.

[0002]

2. Description of the Related Art Due to the market demand for downsizing and weight reduction of standard open induction motors, a structure for increasing the cooling performance of open induction motors is becoming important.

A conventional open type induction motor will be described below. FIG. 3 is a sectional view of a conventional open type induction motor (hereinafter referred to as an electric motor). In FIG. 3, 1 is the shaft of the electric motor, 7 is the anti-load side ball bearing press-fitted on the anti-load side of shaft 1, 8 is the load side ball bearing press-fitted on the load side of shaft 1,
2 is a bracket B that holds the anti-load side ball bearing 7 and has an air hole on the end face. 3 is bracket A that holds the load side ball bearing 8 and that has an air hole on the end face. 4 is bracket A3 and bracket B.
Through bolts that fix 2; 5 is a rotor that is fixed to the shaft 1; 6 is a stator that is provided at a position facing the rotor 5; 9 is a frame that fixes the stator 6; A coil for generating a magnetic field in the gap between the rotors 5, 11 is a casting fan formed on the aluminum die casting of the rotor 5, and 12 is a frame 9
It is a wind hole formed on the circumference of.

The electric motor is a device for generating an electromagnetic force by a current induced in the rotor 5 by a magnetic field excited in the gap and giving a rotating force to the shaft 1 to transmit the power to a load. Generates wind by rotating. The wind passes through the end faces of the brackets A3 and B2 and is discharged from the air holes 12 of the frame 9, cools the coil ends of the coils 10 and contributes to heat dissipation due to loss of the electric motor.

[0005]

However, in the above conventional configuration, the shaft of the electric motor rotates and the wind generated by the casting fan hits only the coil end, and the copper loss and the stator inside the status lot due to the loss of the electric motor. Heat moves to the outer circumference of the stator due to the temperature gradient due to the iron loss of the motor, but because there is no wind, heat exchange with the atmosphere is insufficient, which reduces the efficiency of cooling the wind, making it difficult to reduce the size and weight of the motor. Had the problem.

The present invention solves the above-mentioned problems of the prior art. In order to effectively use the air volume by a casting fan and to cool the coil end and the outer circumference of the stator, the flow straightening vanes (in the bracket) that change the direction of the air flow. By providing ribs provided in the circumference in the axial direction) and increasing the outer diameter of the bracket at a position facing the chords of the stator core in order to provide a gap with the outer circumference of the stator, the cooling effect efficiency can be greatly increased.
It is intended to provide a lightweight electric motor.

[0007]

To achieve this object, an electric motor according to the present invention has a bracket outer diameter at a position opposed to a chord of a stator core in order to form a gap between a rectifying blade that changes a direction of air flow and a stator outer circumference. Is getting bigger.

[0008]

With this structure, the wind flows over the outer circumference of the stator in the axial direction of the electric motor to cool the outer circumference of the stator, and the efficiency of the cooling effect of the air is greatly increased, which greatly contributes to downsizing and weight reduction of the electric motor. Is.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1a is a shaft of an electric motor, 7a is an anti-load side ball bearing press-fitted to the anti-load side of the shaft 1a, 8a is a load side ball bearing press-fitted to the load side of the shaft 1a, and 2a is an anti-load. Brackets B and 3a, which hold side ball bearings 7a and have air holes on their end faces, are brackets A and 3A, which hold load side ball bearings 8a and have air holes on their end faces, are fixing screws for fixing brackets A3a and B2a to the outer circumference of the stator. 5a is axis 1
A rotor fixed to a, 6a is a stator provided at a position facing the rotor 5a, 10a is a coil for generating a magnetic field in a gap between the stator 6a and the rotor 5a when a current flows, and 11a is an aluminum of the rotor 5a. A casting fan formed on the die casting, 12a is a bracket A
3a, air holes provided on the outer periphery of the bracket B2a, 13
Is a gap in which the outer diameter of the bracket is increased at a position facing the chords of the stator core, and the outer circumference of the stator is provided, and 14 is an arrow indicating the direction of air flow by the casting fan 11a.

The wind generated by the casting fan 11a due to the rotation of the shaft 1a of the electric motor causes the bracket A3a,
The cut-and-raised parts flow from the air holes on the end surface of the bracket B2a as guides and flow along the coil ends of the coil 10a to the inner circumferences of the brackets A3a and B2a. The air flows from the air holes provided on the outer periphery of the bracket A3a and the bracket B2a to the position facing the arc of the stator 6a, and the stator 6a and the bracket A3a, the bracket B2 to the position facing the chord of the stator.
The wind flows from the gap a and flows along the outer circumference of the stator. As a result, the stator 6a and the coil ends of the electric motor are cooled, and the cooling effect efficiency is greatly increased.

Regarding the electric motor configured as described above,
By arranging the bracket A3a and the bracket B2a, the heat loss due to the loss of the electric motor is greatly contributed, so that the efficiency of the electric motor is improved and the size and weight of the electric motor are greatly contributed.

FIG. 2 is a detailed view of the bracket in one embodiment of the present invention. Reference numeral 15 denotes a bracket A3a and a bracket B2a facing the boundary line between the arc and the chord of the stator.
A straightening vane that extends in the axial direction on the inner circumference of the. By guiding the flow of wind to the outer circumference of the stator by the rectifying blades 15, it greatly contributes to the heat dissipation due to the loss of the electric motor, which improves the efficiency of the electric motor and greatly contributes to the downsizing and weight reduction of the electric motor.

[0014]

As described above, according to the present invention, the flow direction of the wind is changed by the gap between the stator 6a and the brackets A3a and B2a, which greatly contributes to the heat dissipation due to the loss of the motor, thus improving the efficiency of the motor. Therefore, the size and weight can be reduced as compared with the conventional product.

[Brief description of drawings]

FIG. 1 is a sectional view of an electric motor according to an embodiment of the present invention.

FIG. 2 is a detailed view of a bracket according to an embodiment of the present invention.

FIG. 3 is a half sectional view of a conventional electric motor

[Explanation of symbols]

 1,1a Shaft 2,2a Bracket B 3,3a Bracket A 4 Through bolt 4a Fixing screw 5,5a Rotor 6,6a Stator 7,7a Anti-load side ball bearing 8,8a Load side ball bearing 9 Frame 10,10a Coil 11 , 11a Casting fan 12, 12a Air hole 13 Gap 15 Straightening vane

Claims (2)

[Claims] 1. A stator comprising a stator core having chords located at equal intervals on the circumference, a rotor forming a casting fan on an end ring of the rotor by aluminum die casting, and an arc on the outer circumference of the stator. Based on the outer diameter of the ball bearings that form the rotor, it has two brackets that are held from both sides of the load side and the anti-load side, and the brackets are provided with air holes in the circumferential direction and the radial direction from the end face center, The cut-and-raised part is formed by bending in the outer peripheral direction of the bracket at the same time when the air holes are formed. An open type induction motor, wherein the outer diameter of the outer peripheral surface of the bracket is larger than the outer diameter. 2. The open type induction motor according to claim 1, wherein ribs are provided on a boundary line extending in the axial direction of the electric motor at a position facing the arc of the stator and a position facing the chord.