Electric motor for compressor, compressor, and freezing cycle device

Abstract

An object is to provide an electric motor for a compressor starting torque for which can be increased with the rise of the price of a component and a deterioration in efficiency in operation suppressed. The electric motor for the compressor is housed with a compressor element for compressing a cooling medium in an airtight container and connected to the compressor element via a driving axis to drive the compressor element. The electric motor for the compressor comprises a stator fixed to the inner periphery portion of the airtight container, a rotator (11) which is arranged on the inner side of the stator and which has a rotator core (11a), and a double squirrel-cage conductor which is cast in the rotator core (11a) and which is constituted by a secondary conductor comprising an outer layer secondary conductor and an inner layer secondary conductor and an end ring (32). In the rotator core (11a), an air hole (33) which is the passage of the cooling medium is provided. The inner diameter side of the end ring (32) is enlarged to a driving axis side in such a manner that the air hole (33) is sealed. The end ring (32) has a cutting (34) for allowing the air hole (33) to be communicated with the space of the airtight container so as not to seal the air hole (33).

Description

technical field [0001] The present invention relates to a motor for a compressor, a compressor and a refrigeration cycle device. Background technique [0002] In a compressor used in a refrigerating and air-conditioning apparatus such as an air conditioner, a brushless DC motor, an induction motor, or the like is used as a motor that drives a compression mechanism. Among the induction motors, an ordinary cage type induction motor (single cage type) is mainly used. [0003] Induction motors include three-phase induction motors and single-phase induction motors. When an induction motor is used for a compressor, since the starting torque of a three-phase induction motor is large, there are few problems related to starting. However, in single-phase induction motors, sufficient starting torque cannot be obtained only with an externally connected operation capacitor. Therefore, a capacitor for starting may be added in addition to a capacitor for operation (for example, refer to...

AI Technical Summary

Problems solved by technology

[0007] However, as in the above-mentioned Patent Document 1, since the method of adding a capacitor for starting requires a switch for opening and closing the capacitor for starting, there is a problem that the cost of parts becomes higher.

[0008] In addition, the method of shifting the phase difference between the main winding and the auxiliary winding by 90° (electrical angle) has the problem that it cannot be realized due to the number of slots of the stator core.

[0009] In addition, the method of increasing the secondary resistance of the rotor to increase the starting torque has the problem of lowering the efficiency during operation of the single-phase induction motor.

Images