JPH09261924A - Rotor cooling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cooling capability with the robust apparatus in the method for cooling rotor. SOLUTION: A rotor 3 to be cooled is provided in a stator 2 so as to face the inner circumferential side of the stator 2 with a gap therebetween. Retaining members which consist of a step part 32 and a collar 4 in which circumferential grooves 33 having inclined side walls 33c on their outer sides are formed are provided on both the sides of a rotor core 31 in its axial direction. Coolant is spouted out against the inclined side walls from nozzles 51 which are provided on a stator 2 side. As the heat generated by the rotor 3 is transmitted through the contact boundaries between the rotor core 31 and the step part 32 and between the collar 4 and the rotor core 31 and taken away by the coolant, the thermal stresses are not applied to an end ring 35 and rotor bars 34.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for cooling a rotor of a rotary electric machine.

[0002]

2. Description of the Related Art As a conventional technique, as a cooling method of a rotor provided facing a stator with a gap, a cooling liquid is sprayed from a nozzle provided on the stator toward an end ring of the rotor. (For example, JP-A-64-16
No. 238).

[0003]

Generally, the rotor of an induction type rotary electric machine has a rotor core in which ferromagnetic materials are laminated, and
For example, the rotor bar having a large linear expansion coefficient and the end ring are integrally formed by die casting. However, in the conventional technique, although the cooling capacity is high, since the end ring is partially cooled by the cooling liquid, the thermal stress due to the difference in the linear expansion coefficient between the rotor core and the rotor bar is repeatedly applied to the rotor bar at the time of start-up and load fluctuation, and Can be damaged by fatigue. Therefore, it is an object of the present invention to provide a method of cooling a rotor having high cooling capacity and excellent strength.

[0004]

In order to solve the above problems, cooling of a rotor having a rotor core facing the inner circumference of a stator having windings housed in slots of the stator core with a gap therebetween. In the method, on both axial side surfaces of the rotor core,
A locking member provided with a circumferential groove having an inclined side surface on the outer peripheral side is provided, and the refrigerant is sprayed to the circumferential groove.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In a method of cooling a rotor having a rotor core facing each other with a gap on the inner peripheral side of a stator having windings housed in slots of the stator core, an axial direction of the rotor core The step and the collar of the shaft are provided in close contact with both sides, and the circumferential groove with the inclined side surface is provided on the outer peripheral side of the step and the collar. From the nozzle provided on the stator side, face the inclined side surface of the circumferential groove. And spray the refrigerant. Since the heat generated in the rotor core is carried away by the refrigerant through the step portion of the shaft and the contact surface with the collar, thermal stress is not applied to the end ring and the rotor bar.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a front sectional view showing an embodiment of the present invention, and FIG. 2 is a partial sectional view of FIG. This example is applied to a rotor of an induction motor. A stator 2 having a winding provided in a slot of a laminated core is fitted to the inner diameter of the frame 1. The rotor 3 is opposed to the inner peripheral side of the stator 2 via a gap. The rotor 3 includes a rotor core 31 formed by laminating disk-shaped thin plates, a rotor bar 34, and an end ring 3.
5 is integrally formed by die casting. One side surface of the rotor core 31 is a step of the shaft 30 in which a ring groove 37 for accommodating the end ring 35 is formed on a side surface, and a circumferential groove 33 having an inclined side surface 33C inclined in the inclination direction of the nozzle 51 is provided on the outer peripheral surface. It is in close contact with the portion 32. Rotor core 3
The other side surface of 1 is a collar 4 provided with a ring groove 37 for accommodating the end ring 35 on the side surface and a circumferential groove 33 having an inclined side surface 33C inclined on the outer peripheral surface in the inclination direction of the nozzle 51.
It is closely attached to the side of. The circumferential groove 33 may be straight without providing the inclined side surface 33C. Rotor core 3
The shaft 1 and the collar 4 are shrink-fitted onto the shaft 30. A plurality of nozzles 51 facing the circumferential groove 33 and blowing out the refrigerant.
When the refrigerant 10 is blown out of the
It is provided radially so as to hit the vicinity of the root of 3C.
When the direction of rotation of the rotor 3 is fixed, if the direction of the nozzle 51 is tilted in the direction of rotation, the resistance due to the spraying of the refrigerant 10 is reduced, and the efficiency of the rotary electric machine is improved.
The nozzles 51 are radially provided on the inner peripheral side of the pair of refrigerant supply jackets 5 provided on both side surfaces of the stator 2, and the outer ends of the nozzles 51 are communicated with the communication ring 52 of the ring. A communication hole 53 is provided on the outer diameter side of the communication ring 52. The communication hole 53 communicates with the outer diameter side of the refrigerant supply jacket 5. Above the coolant supply jacket 5,
An O-ring storage groove 54 is provided surrounding the communication hole 53,
An O-ring 55 is housed in the O-ring housing groove 54, and an axial notch 56 is provided on the lower side. The outer diameter side of the coolant supply jacket 5 is fitted to the inner peripheral side of the frame 1. The frame 1 is provided with a coolant supply hole 11 that communicates with the communication hole 53. The refrigerant supply pipe 6 is connected to the refrigerant supply hole 11, and the refrigerant 10 is pressurized and supplied from the refrigerant supply device 7 such as a pump. On the lower side of the frame 1 between the coolant supply jacket 5 and the stator 2, a circumferential groove 33 is formed.
A refrigerant discharge port 12 is provided at a position opposite to, and a refrigerant recovery pipe 8 is connected to the refrigerant recovery device 9 such as a vacuum pump to suck and recover the refrigerant 10. A heat dissipation device (not shown) is provided between the refrigerant supply device 7 and the refrigerant recovery device 9.
May be provided to circulate the refrigerant 10.

Further, although the example of the rotor of the induction motor has been described in the embodiment, it may be applied to a rotor of a magnetic bearing having no end ring or a rotor of a synchronous rotating electric machine provided with a permanent magnet. In this case, the side surface of the step portion 32 and the collar 4 is made flat without providing the ring groove 37 for accommodating the end ring 35, and the side surfaces of the step portion 32 and the collar 4 are directly adhered to both side surfaces of the rotor core 31.

The operation will be described below. Refrigerant supply device 7
When the refrigerant 10 pressurized from is sprayed from the nozzle 51 through the refrigerant supply pipe 6, the refrigerant supply hole 11, the communication hole 53, and the communication ring 52 to the vicinity of the base of the inclined side surface 33C of the circumferential groove 33, Is transmitted through the inclined side surface 33C and is blown away by centrifugal force. At this time, the refrigerant 10 has the inclined side surface 3
Since 3C is traced from the root toward the outer circumference, the contact surface becomes wider and the heat absorption is improved. Then, the heat generated by the copper loss and the iron loss generated in the rotor 3 passes through the step 32 and the collar 4 and is taken by the refrigerant 10 in the circumferential groove 33. The refrigerant 10 that has taken the heat is blown off by the inclined side surface 33C, and the refrigerant outlet 1
Accumulates around 2. Refrigerant 10 accumulated near the refrigerant outlet 12
Passes through the refrigerant recovery pipe 8 and is sucked and recovered by the refrigerant recovery device 9.

[0009]

As described above, according to the present invention,
While the rotor core remains normal, the heat generated in the rotor core is removed by blowing the refrigerant onto the stepped part of the shaft that is in close contact with both sides of the rotor core and the inclined side surfaces of the circumferential groove provided in the collar. As a result, it is possible to cool efficiently near the heat source, and the end ring and rotor bar are not subject to thermal stress, which is excellent in strength.The refrigerant is collected so that it accumulates inside the rotating electric machine. It has the effect of never happening.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of the present invention.

FIG. 2 is a partial sectional view of FIG.

[Explanation of symbols]

 1 Frame 10 Refrigerant 11 Refrigerant Supply Hole 12 Refrigerant Discharge Port 2 Stator 3 Rotor 30 Shaft 31 Rotor Core 32 Step Part 33 Circumferential Groove 33C Inclined Side 34 Rotor Bar 35 End Ring 37 Ring Groove 4 Color 5 Refrigerant Supply Jacket 51 Nozzle 52 Communication Ring 53 Communication Hole 54 O Ring Storage Groove 55 O Ring 56 Notch 6 Refrigerant Supply Pipe 7 Refrigerant Supply Device 8 Refrigerant Recovery Pipe 9 Refrigerant Recovery Device

Claims (2)

[Claims] 1. A method of cooling a rotor having a rotor core, which is opposed to an inner peripheral side of a stator having windings housed in slots of the stator core with a gap therebetween, wherein both axial sides of the rotor core are provided. The shaft step and the collar are provided in close contact with the surface, the circumferential groove having the inclined side surface is provided on the outer peripheral side of the step portion and the collar, and the inclined side surface of the circumferential groove is formed from the nozzle provided on the stator side. A method for cooling a rotor, characterized in that a refrigerant is sprayed toward the. 2. The method for cooling a rotor according to claim 1, wherein the refrigerant is sprayed while being inclined in a rotation direction of the rotor.