JPH0621349U - Rotating machine rotor - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a rotor of a rotary electric machine supported by a magnetic bearing, in particular, with improved cooling. [Structure] A rotor core 1 made of a laminated silicon steel plate obtained by die-casting a secondary conductor 2 in an axial direction, and a short-circuit ring 3 of a secondary conductor 2.
In a rotor of a rotary electric machine comprising a rotor 4 of a radial magnetic bearing and a disk 7 of a thrust magnetic bearing, the rotor core 1, the rotor 4 of the radial magnetic bearing and the boss portion 71 of the disk 7 of the thrust magnetic bearing are used as shafts. A plurality of ventilation holes 9 communicating with each other in the direction, and ventilation holes 10 are provided in communication with the ventilation holes 9 in the radial direction of the disk 7 of the thrust magnetic bearing. Further, as an applied form, an oblique narrow hole 101 directed to the inner diameter of the electromagnet 8 is added to the disk 7 of the thrust magnetic bearing so as to communicate with the ventilation hole 10.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotor of a rotary electric machine supported by magnetic bearings, and particularly, to improve cooling.

[0002]

[Prior art]

 Conventionally, in order to cool the center of the rotor of a squirrel-cage induction motor that is poorly cooled, an axial ventilation hole is provided in the laminated iron core of the rotor, and this ventilation hole and the air gap are communicated in the radial direction. There is one in which a rotor disk provided with air holes is inserted in the center of the rotor (for example, Japanese Patent Laid-Open No. 2-299436).

[0003]

[Problems to be solved by the device]

 However, since the rotating disk is provided in the central portion of the rotor core, iron loss occurs. Moreover, since the diameter of the rotating disk is slightly smaller than that of the rotor core, the pumping action (centrifugal force) acting on the ventilation holes of the rotor disk is small, and sufficient cooling cannot be performed. Further, when applied to a rotor of a rotary electric machine supported by radial and thrust magnetic bearings, there is a problem that the thrust disk cannot be cooled in particular. Therefore, an object of the present invention is to efficiently cool the rotor of a rotating electric machine that is supported by magnetic bearings and rotates at high speed.

[0004]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, a rotor core made of a laminated silicon steel plate in which a secondary conductor 2 is die-cast in the axial direction, a short-circuit ring of the secondary conductor, a rotor of a radial magnetic bearing, and a disk of a thrust magnetic bearing. In a rotor of a rotating electric machine consisting of a Provide ventilation holes in the radial direction of the bearing disc. Further, as an applied form, an oblique narrow hole 101 directed to the inner diameter of the electromagnet 8 of the thrust magnetic bearing may be added to the disk 7 of the thrust magnetic bearing in communication with the ventilation hole 10.

[0005]

[Action]

 As described above, since the thrust disk is provided with ventilation holes to discharge air into the air gap along the radial direction, the rotor core has only the ventilation holes along the axial direction, so that the rotor core machine Iron loss on the rotor side can be reduced without lowering the strength. Furthermore, because the vent holes are provided on the outer circumference of the thrust disk, which has a larger radius than the rotor core, the centrifugal force that acts on the cooling air is large and the cooling air volume is large, greatly improving the cooling of the rotor. can do.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to FIG. A short-circuit ring 3 is firmly fixed to the load side of a rotor core 1 made of a laminated silicon steel plate in which a secondary conductor 2 that is shrink-fitted on a shaft 4 is axially die-cast. The rotor 4 of the radial magnetic bearing made of a ferromagnetic material is shrink fitted to the shaft 5 by bringing it into contact with the load side of the short-circuit ring 3. An electromagnet 6 of the radial magnetic bearing is opposed to the outer circumference of the rotor 4 of the radial magnetic bearing via a gap. On the other hand, the short-circuit ring 3 is firmly fixed to the anti-load side of the rotor core 1. A disk 7 of a thrust magnetic bearing made of a ferromagnetic material is shrink-fitted to the shaft 5 by being brought into contact with the anti-load side of the short-circuit ring 3. On both axial sides of the disk 7 of the thrust magnetic bearing, electromagnets 8 of the thrust magnetic bearing are opposed to each other through a gap. The disk 4 of the thrust magnetic bearing is brought into contact with the anti-load side, and the rotor 4 of the radial magnetic bearing made of a ferromagnetic material is shrink fitted onto the shaft 5. The rotor 4 of the radial magnetic bearing, the rotor core 1, and the boss portion 71 of the disk 7 of the thrust magnetic bearing are axially arranged at a position larger than the outer diameter of the shaft 5 and smaller than the inner diameter of the secondary conductor 2. A plurality of communicating ventilation holes 9 are provided on the same pitch circle. As shown in FIG. 2, ventilation holes 10 communicating with the ventilation holes 9 are provided radially in a radial direction at the axial center of the disk 7 of the thrust magnetic bearing. The ventilation hole 10 forms an outlet 11 on the outer circumference of the disk 7 of the thrust magnetic bearing. When the rotor rotates at a high speed, the cooling air flows from both ends of the rotor by the pumping action of the ventilation holes 10 as shown by the arrows in the figure, and inside the ventilation holes 9 the rotor core 1, the radial The gas is discharged from a discharge port 11 through a ventilation hole 10 provided inside the rotor 4 of the magnetic bearing and the disk 7 of the thrust magnetic bearing. The ventilation hole 10 set in the disk 7 of the thrust magnetic bearing does not necessarily have to be at an angle perpendicular to the tangential line in the rotation direction, but may be tilted in the direction opposite to the rotation direction. FIG. 3 shows a second embodiment. In the disk 7 of the thrust magnetic bearing in the embodiment, the slender small holes 101, 101 directed toward the inner diameter of the electromagnet 8 are communicated with the vent hole 10 at a position where the magnetic field generated by the electromagnet 8 does not affect. With this configuration, the heat generated by the coil can be directly forcibly cooled.

[0007]

[Effect of device]

 As described above, according to the present invention, since the ventilation holes extending in the radial direction are provided in the disk of the magnetic bearing, it is possible to obtain a sufficient amount of cooling air without lowering the mechanical strength of the rotor core. The temperature rise of the rotor can be prevented.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a side sectional view of a rotor showing a second embodiment of the present invention.

[Explanation of symbols]

 1 rotor core 2 secondary conductor 3 short-circuit ring 4 rotor of radial magnetic bearing 5 shaft 6 electromagnet of radial magnetic bearing 7 disk of thrust magnetic bearing 8 electromagnet of thrust magnetic bearing 9, 10 ventilation hole 11 exhaust port 61, 81 excitation coil 71 Thrust magnetic bearing disk boss 101 Small hole

Claims (3)

[Scope of utility model registration request] 1. A rotor core 1 made of a laminated silicon steel plate obtained by die-casting a secondary conductor 2 in the axial direction, a short-circuit ring 3 of a secondary conductor 2, a rotor 4 of a radial magnetic bearing, and a disk 7 of a thrust magnetic bearing. In the rotor of the rotating electric machine, the rotor core 1, the rotor 4 of the radial magnetic bearing and the boss 71 of the disk 7 of the thrust magnetic bearing are axially communicated with each other, and a plurality of ventilation holes 9 are provided. A rotor of a rotary electric machine, comprising: a ventilation hole 10 which is provided in a radial direction of a disk 7 of a thrust magnetic bearing in communication with the rotor. 2. The rotor of a rotary electric machine according to claim 1, wherein a ventilation hole provided in a radial direction of the disk 7 of the thrust magnetic bearing is inclined in a direction opposite to a rotation direction. 3. An oblique narrow hole 101, which is communicated with the ventilation hole 10, is provided in the disk 7 of the thrust magnetic bearing toward the inner diameter of the electromagnet 8 of the thrust magnetic bearing.
Or the rotor of the rotating electric machine according to 2.