JP2004336925A - Electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor which can regulate imbalance without impairing the efficiency of the electric motor. <P>SOLUTION: The electric motor including a rotor having a magnet embedded in a rotor core 11 and a stator includes a counterweight integral type end plate 13 in which a counterweight 13A is integrated with the end plate 13B, and a cutout part provided on the end plate 13B of the counterweight integral type end plate 13. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor constituting a hermetic compressor or the like.
[0002]
[Prior art]
Conventionally, as a rotor of an electric motor mounted on a hermetic compressor, a magnet is arranged on an outer peripheral portion of a rotor core, and a thin metal tube made of a non-magnetic material is fitted. The end plate made of a non-magnetic material was fixed with rivets together with a balance weight for correcting imbalance caused by the compression mechanism of the hermetic compressor.
[0003]
In some rotors having such a configuration, a balance adjustment hole is provided in the rotor core at a position symmetrical to the balance weight (for example, see Patent Document 1).
[0004]
Further, in recent years, there has been a motor adopting a structure in which a magnet is embedded in a rotor core as shown in FIG. 4 in order to realize high efficiency of the motor (for example, see Patent Document 2). In the rotor of the electric motor having such a structure, end plates are arranged on both end surfaces of the rotor core in the same manner as described above, and are fixed with rivets.
[0005]
[Patent Document 1]
JP-A-5-304751 (FIG. 4)
[Patent Document 2]
JP-A-9-9537 (Fig. 5)
[0006]
[Problems to be solved by the invention]
However, in a rotor having a structure in which a magnet is embedded in a rotor core, the arrangement of rivets is limited. That is, it is originally desirable to attach the balance weight to the outer peripheral side of the rotor, and it is also preferable to arrange the rivets on the outer peripheral side. However, it is a hindrance to the magnetic circuit and the efficiency is reduced.
[0007]
Further, in a hermetic compressor in which the imbalance caused by the compression mechanism is large, if the unbalance is adjusted only by the balance weight, the balance weight becomes large, and as a result, the motor becomes larger.
[0008]
In order to reduce the balance weight, it is conceivable to provide a balance adjusting hole in the rotor core as described above. However, in a rotor having a structure in which a magnet is embedded in the rotor core, the reluctance is adjusted according to the magnet torque. Since the torque is also used, the size of the hole is limited in relation to the efficiency.
[0009]
An object of the present invention is to provide a motor capable of adjusting imbalance without impairing the efficiency of the motor.
[0010]
[Means for Solving the Problems]
The present invention has been made in view of the above-described conventional problems, and provides a balance weight integrated end plate in which a balance weight and an end plate are integrated, and a notch in an end plate portion of the balance weight integrated end plate. It is configured to be provided. With the above configuration, the balance weight can be arranged on the outer peripheral side of the rotor regardless of the position of the rivet, even though the motor is a highly efficient motor.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 of the present application is directed to a rotor core, a magnet embedded in the rotor core, a balance weight, end plates at both ends of the rotor core, and the rotor core having the end. An electric motor rotor having a plurality of rivets for fixing a plate, and an electric motor comprising a stator, wherein the balance weight and the end plate are integrated with a balance weight integrated end plate, and the balance weight integrated end plate is An electric motor characterized in that a cutout is provided in an end plate portion, in which a rivet can be arranged inside a magnet of a rotor and does not obstruct a magnetic path of the magnet.
[0012]
According to a second aspect of the present invention, there is provided the electric motor according to the first aspect, wherein a plurality of rivets are arranged at irregular intervals, and the balance weight portion can be arranged at a predetermined position.
[0013]
According to a third aspect of the present invention, there is provided a hermetic compressor having the electric motor according to the first or second aspect.
[0014]
【Example】
Hereinafter, specific examples of the present invention will be described with reference to the drawings.
[0015]
As shown in FIG. 1, the rotor of the electric motor has a rotor core 11, a magnet 12 and a balance weight integrated type end plate 13 fixed by rivets 14.
[0016]
As shown in FIG. 2, the rivet 14 is disposed inside the rotor magnet 12 by using the balance weight integrated end plate 13, and the balance weight portion 13 A of the balance weight integrated end plate 13 is Since the rivet 14 can be arranged on the outer peripheral side of the rotor and the rivet 14 is arranged inside the magnet 12 of the rotor, the rivet 14 does not hinder the magnetic path of the magnet 12 and can prevent a decrease in efficiency. .
[0017]
In addition, by providing a notch 15A corresponding to the shape of the embedded magnet and a notch 15B provided in the inner diameter portion in the end plate portion 13B of the balance weight integrated type end plate 13, a negative balance can be achieved in the end plate portion 13B. Thus, the size of the main balance weight portion 13A can be reduced. The shapes and positions of the cutouts 15A and 15B are not limited to the present embodiment, and similar effects can be obtained even if the cutouts 15A and 15B have other shapes.
[0018]
FIG. 3 shows the rivet positions in the rotor, and the intervals 31A and 31B of the rivets 14 are unequal. Thereby, it is possible to prevent the rotor core 11 from being attached to an incorrect position. The number of rivets 14 is not limited to three.
[0019]
【The invention's effect】
As described above, according to the present invention, a small, high-efficiency, high-quality electric motor can be obtained. By mounting the electric motor having the above-mentioned advantageous effects on a hermetic compressor, it is possible to obtain a hermetic compressor with low vibration and low noise.
[Brief description of the drawings]
1 is a sectional view of a rotor of the present invention; FIG. 2 is a top view of a rotor of the present invention; FIG. 3 is a top view of a rotor in which rivets of the present invention are arranged at unequal intervals; Cross section of rotor [Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Rotor iron core 12 Magnet 13 Balance weight integrated type end plate 13A Balance weight part 13B End plate part 14 Rivet 15A, 15B Notch part 31A, 31B Spacing of rivet

Claims (3)

A motor rotation having a rotor core, magnets embedded in the rotor core, balance weights, end plates at both ends of the rotor core, and a plurality of rivets for fixing the end plates to the rotor core. A balance weight and the end plate, wherein the balance weight and the end plate are integrated into a balance weight integrated end plate, and a notch is provided in an end plate portion of the balance weight integrated end plate. An electric motor characterized by the following. The electric motor according to claim 1, wherein the arrangement intervals of the plurality of rivets are unequal. A hermetic compressor comprising the electric motor according to claim 1.

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