JPH09163644A - Rotor of electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the operation of adjusting balance by laminating an iron core having a plurality of balance correcting holes in the circumferential direction in a plate surface on both sides of a laminated iron core formed by laminating an iron core which does not have the balance correcting holes in a plate surface. SOLUTION: A rotor iron core 3 is fitted to a rotating shaft 1 with a thin steel plate being blanked and laminated and is formed of a laminated iron core 4 which is laminated and does not have a balance correcting hole in a plate surface and a laminated iron core 5 which is laminated and has a plurality of balance correcting holes in the circumferential direction in the plate surface on both sides of the laminated iron core 4. Also, a balance correcting hole 6 in the axial direction is formed in the rotor iron core 3. Putty 8 is applied to the plate surface of the laminated iron core 4 which is in the balance correcting hole 6 of the rotor iron core 3 and does not have the balance correcting hole 6 of the rotor iron core 3 and also to the side wall of the balance correcting hole 6. For that reason, the putty 8 is prevented from coming off and falling off from the balance correcting hole 6 by the vibrations and the impact of the rotor iron core 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor of an electric motor which enables easy balance adjustment.

[0002]

2. Description of the Related Art As shown in FIG. 3, a rotor of a conventional electric motor is provided with a rotor core 12 formed by punching and stacking iron plates on a rotary shaft 11, and a permanent magnet 13 is provided on the outer periphery of the rotor core 12.
To reduce vibration and noise caused by unbalance of the rotor when such an electric motor is driven, side plates 14 having a U-shaped cross section are provided on both end faces of the rotor core.
A putty 15 is attached to the side plate 14 to adjust the balance of the rotor.

[0003]

The rotor of the electric motor constructed as described above has a rotor core 12 formed by laminating thin steel plates.
Since the side plates 14 had to be attached to both end faces of the above, the work was complicated. As another measure, a through hole extending in the axial direction is provided in the rotor core, and putty is attached to the side wall of this through hole.However, since the putty is attached only to the side wall of the through hole, the diameter of the through hole is If the size is small, the workability is poor, and if the size of the through hole is increased to solve this problem, the magnetic circuit is adversely affected. Therefore, an object of the present invention is to simplify the rotor balance adjustment work without attaching a side plate to the rotor core and without affecting the magnetic circuit.

[0004]

In order to achieve the above object, the present invention relates to a rotor of an electric motor in which a permanent magnet is attached to the outer periphery of a rotor iron core formed by punching and laminating thin steel plates. On both sides of a laminated core formed by laminating iron cores having no balance correction holes on the plate surface, a laminated core formed by laminating iron cores having a plurality of balance correction holes in the circumferential direction on the plate surface is provided.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. FIG. 1 is an upper side sectional view of a rotor showing a first embodiment of the present invention. Reference numeral 1 is a rotary shaft, and 2 is a bearing attached to the rotary shaft, which is fixed to a bracket (not shown). Reference numeral 3 denotes a rotor core which is obtained by punching and stacking thin steel plates and attaching it to the rotary shaft 1. The laminated core 4 has no balance correction holes on the plate surface, and the balance correction holes on both sides of the laminated core 4 are circular circles. It is composed of a laminated core 5 having a plurality of layers in the circumferential direction. Therefore, an axial balance correction hole 6 is formed in the rotor core 3. Reference numeral 7 is a permanent magnet attached to the outer periphery of the rotor core 3, 8 is putty, and a plate surface and a balance of the laminated core 4 having no balance correction holes for the rotor core 3 in the balance correction holes 6 of the rotor core 3. It is attached to the side wall of the correction hole 6. Therefore, putty 8
Does not fall out of the balance correction hole 6 or fall due to vibration or shock of the rotor core. To adjust the balance of the rotor, the rotor is attached to the balancing machine and the balancing machine is driven to detect the amount and position of the imbalance. This is done by attaching putty to the balance correction holes where the weight is insufficient. FIG. 3 shows a second embodiment of the present invention, in which a laminated iron core 5 having a balance correction hole on the plate surface and a laminated iron core 4 having no balance correction hole on the plate surface are set to the length of the permanent magnet 7. Three rotor blocks 9 laminated to have substantially the same laminated thickness are fixed to a rotary shaft 10, and putty 8 is attached to the balance correction holes on the outer end surfaces of the rotor blocks 9 on both sides in the axial direction. Therefore, even when increasing the laminated thickness of the rotor core in order to increase the output of the electric motor, it is possible to easily provide the balance correction holes for the rotor core simply by increasing the number of rotor blocks. Further, it is possible to provide a rotor structure that can be balanced at low cost.

[0006]

As described above, according to the present invention, the balance adjustment work of the rotor can be easily performed without using the side plate for attaching the putty and without affecting the magnetic circuit.

[Brief description of the drawings]

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

FIG. 2 is an upper side sectional view of a rotor showing a second embodiment of the present invention.

FIG. 3 is an upper side sectional view of a rotor showing a conventional example.

[Explanation of symbols]

1 rotary shaft, 2 bearings, 3 rotor core, 4 laminated core, 5 laminated core, 6 balance correction hole, 7 permanent magnet, 8 putty, 9 rotor block, 10 rotary shaft

Claims (2)

[Claims] 1. A rotor of an electric motor, in which permanent magnets are attached to the outer periphery of a rotor core formed by punching and stacking thin steel sheets, wherein the rotor core is laminated with an iron core having no balance correction hole on the plate surface. A rotor of an electric motor, characterized in that a laminated iron core is formed by laminating iron cores having a plurality of balance correction holes in the plate surface in the circumferential direction on both sides of the laminated iron core. 2. A plurality of rotor core blocks having a laminated laminated core having a plurality of balance correction holes in the plate surface in the circumferential direction on both sides of a laminated laminated core having no balance correction holes on the plate surface. The rotor of the electric motor according to claim 1, wherein the rotor cores are arranged in parallel in a direction.