JP2001190040A - Rotor of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily change a position where a rotor core is attached to a shaft, and avoid noise, while a whole structure of a motor is not changed, or a position of a magnet center is not changed. SOLUTION: Two types of steel plates 6a and 6b of which a rotor core 2 is composed and, which have holes 3 with respectively different diameters at center parts thereof, are provided. Both the side parts of the rotor core 2 are composed of the steel plates 6a with the holes 3 with larger diameters and the center part of the rotor core 2 is composed of the steel plates 6b with the holes 3 with smaller diameters. Respective thickness of the two types of layered steel plates 6a and 6b are selected arbitrarily.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a rotor core formed by laminating steel plates, and a shaft which is inserted into a hole provided at the center of the rotor core and mounted by press-fitting or caulking. Motor rotor.

[0002]

2. Description of the Related Art In a rotor provided in an electric motor, for example, a rotor of a small induction motor usually has a rod-shaped shaft and a shaft inserted into and fixed to an inner diameter portion formed in a cylindrical shape. Consists of a core.

The structure of a rotor provided in this small induction motor will be described with reference to FIG. FIG. 3 is a partial side sectional view of a rotor of a conventional small induction motor.

[0004] In FIG. 3, a rotor 11 has a rotor core 12 formed in a cylindrical shape and a rod shape, and penetrates a hole 13 provided in a central portion of the rotor core 12, and Shaft 14 caulked at both end faces (arrows) of 12
It is composed of

Further, bearings 15 are provided at both ends of the shaft 14.
a, 15b are arranged to make the rotor 11 rotatable.

The rotor core 12 is made of a thin disk-shaped steel plate 16.
a, 16b, and a secondary winding 17 die-cast with aluminum from the core 16;
And a ring-shaped magnet 18 on one end face of the core 16 for detecting the number of rotations.

The core 16 is formed by laminating a hole 13 for penetrating the shaft 14 at the center and steel plates 16a and 16b provided with a plurality of slot holes at an outer peripheral edge of the disk. ing. The secondary winding 17 is formed by casting the inside of the slot hole of the core 16 and the outer peripheral edges of both end surfaces of the core with aluminum.

[0008] In addition, when die casting is performed, the core 16
Since a metal core is press-fitted into the hole 13 and molded, a plurality of steel plates at the end face of the core 16 may be warped outward by the metal core. Therefore, if the shaft 14 is caulked with a steel plate warped outward, the bonding force of the caulked portion will be reduced.

Therefore, in order to form the hole 13 of the core 16, two types of steel plates 16a and 16b having different diameters are used. That is, a plurality of large-diameter steel plates 16a are used at both ends of the core, and a small-diameter steel plate 16b is used at the center.

[0010] The shaft 14 is caulked at the end face of the small-diameter steel plate 16 b in the center of the core 16 to prevent a reduction in the bonding force.

[0011]

In the structure of the conventional rotor, it is necessary to shift the position of the rotor core in order to change the path of the vibration generated between the gap between the rotor and the stator core. However, if only the position of the rotor core is simply shifted, the magnet center with respect to the stator core opposed to the core is shifted, resulting in a decrease in motor efficiency.

When the position of the rotor core is shifted and the position of the stator core is also shifted, the relationship between the stator and the frame holding the stator, or the mounting position of the flange for mounting the electric motor can be changed. There is
The entire motor type must be changed.

[0013]

Therefore, according to the present invention, there are provided two types of steel plates forming a rotor core, wherein two types of steel plates having different diameters of holes formed in a central portion of the steel plates are provided.
This steel plate having a large hole diameter is disposed on both sides of the rotor core, the steel plate having a small hole diameter is disposed in the middle portion, and the two types of steel plates are laminated with an arbitrary thickness. An electric motor rotor is provided.

[0014]

[Function] Of the steel plates having two kinds of hole diameters to be laminated, the thickness of the steel plate having a small diameter is made smaller than that of the conventional steel plate,
By changing the thickness and position of the large-diameter steel plate provided at both ends of the core and the small-diameter steel plate provided in the center, respectively, the type of the entire motor can be changed and the magnet center can be changed. Without changing the position of
The path of the vibration transmitted from the rotor core to the shaft can be changed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a motor rotor according to the present invention will be described with reference to FIGS. 1 and 2, taking a small induction motor as an example. FIG. 1 is a partial sectional side view of a rotor according to the present invention. FIG. 2 is a partial sectional side view of a rotor according to another embodiment of the present invention.

In FIG. 1, a rotor 1 used for an induction motor has a rotor core 2 formed in a cylindrical shape and a rod shape, like a conventional rotor, and is provided at a central portion of the rotor core 2. The shaft 3 is formed by penetrating the provided hole 3 and caulking. Bearings 5 are provided at both ends of the shaft 4.
a, 5b are arranged to make the rotor 1 rotatable.

The core 6 is formed by laminating two types of steel plates 6a and 6b having different diameters of the hole 3 at the center.
The steel plate 6a having the large diameter of the hole 3 is disposed at both ends of the core 6, and the steel plate 6b having the small diameter of the hole is disposed at the center of the core. That is, the core 6 is formed in three layers depending on the difference in the inner diameter.

The thickness of each of the steel plates 6a and 6b is formed by changing the ratio of the thickness to that of the conventional core. That is, the steel plate 6b having a large diameter of the hole provided at both ends of the core 6 is formed thicker than the conventional core, and the steel plate 6b having a small diameter of the hole provided in the middle portion is larger than the conventional core. Is also formed thin.

The shaft 4 is fixed in contact with a steel plate 6b having a small diameter of the core 6. Therefore,
The location where the outer peripheral surface of the shaft 4 is in contact with the inner peripheral surface of the core 6 is related to the magnitude of the run-out of the shaft 4. What is necessary is just to determine the thickness of the small steel plate 6b.

When power is supplied to the motor, torque is generated between the gap between the stator (not shown) and the rotor 1,
The rotor 1 starts rotating. At this time, if gap unevenness or the like exists between the gaps, the gap becomes torque ripple and vibration occurs.

This vibration is transmitted to the shaft 4 via the rotor core 2. Then, vibration is transmitted to a load (not shown) attached to one end of the shaft 4, and the load may resonate and generate noise depending on the number of rotations of the electric motor or the type of the load.

Therefore, as shown in FIG. 2, the thickness or position of the steel plate 6b having a small hole diameter is changed. That is, the thickness or the position of the steel plate 6b with a small diameter of the hole is changed by changing the thickness of the steel plate 6a with a large diameter of the hole provided at both ends of the core 6, respectively. By configuring the core 6 in this manner, the distance from the mounting position of the shaft 4 and the rotor core 2 to the mounting position of the shaft 4 and the load can be changed so that the load does not resonate.

[0023]

According to the present invention, the mounting position of the rotor core and the shaft can be easily changed without changing the type of the entire motor or the position of the magnet center. Generation of noise can be prevented.

[0024]

[Brief description of the drawings]

FIG. 1 is a partial sectional side view of a rotor according to the present invention.

FIG. 2 is a partial sectional side view of a rotor according to another embodiment of the present invention.

FIG. 3 is a partial sectional side view of a rotor of a conventional small induction motor.

[Explanation of symbols]

 1, 11 ... Rotor 2, 12 ... Rotor core 3, 13 ... Hole 4, 14 ... Shaft 5a, 5b, 15a, 15b ... Bearing 6, 16 ... Core 6a, 6b, 16a, 16b ... Steel plate 17 ... Secondary Winding 18 ... Magnet

Claims (1)

[Claims] A rotor core formed by stacking steel plates;
A steel sheet forming a rotor core in a rotor of an electric motor composed of a shaft inserted into a hole provided in a central portion of the rotor core and press-fitted or caulked, etc. The two types of steel plates having different diameters of holes provided in the central portion of the rotor core are provided, the steel plates having the larger diameters are disposed on both sides of the rotor core, and the steel plates having the smaller diameters are disposed in the middle portion, A rotor for an electric motor, wherein the two types of steel plates are laminated with an arbitrary thickness.