Hermetic Electric Compressor

Abstract

The invention provides an airtight motor compressor which ensures the magnetic force of a motor and improves the retentivity of a Nd-Fe-B sintered magnet. The airtight motor compressor has compressing mechanism part which compresses a refrigerant and a motor that drives the compressing mechanism part, wherein the motor includes a stator having a coil and a rotor having an iron core and a permanent magnet, the permanent magnet consists of a Nd-Fe-B compound with middle-heavy rare earth elements being added, the refrigerant is R32, and the amount of the middle-heavy rare earth elements per unit volume of the Nd-Fe-B compound with a grain boundary from a parent-phase grain being 5nm is more than that of the Nd-Fe-B compound with a grain boundary from the parent-phase grain being closer to an inner part than 5nm.

Description

technical field [0001] The present invention relates to a hermetic electric compressor used in refrigerating and air-conditioning equipment and the like. Background technique [0002] Conventionally, hydrogen-containing Freons such as R-134a, R410A, and R407C have been used as refrigerants in refrigerators, air conditioners, refrigerators, and the like. Although these refrigerants do not destroy the ozone layer, they have a large global warming coefficient. [0003] On the other hand, R32 does not destroy the ozone layer and has a global warming coefficient of about 1 / 3 compared to R410A. [0004] However, when R32 is used as the refrigerant, the discharge temperature of the compressor is higher than that of R-134a, R410A, or R407C, and the permanent magnet used in the motor of the compressor may be demagnetized. [0005] Patent Document 1 describes that, when R32 is used as a refrigerant, the durability against high-temperature demagnetization is improved by increasing th...

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Problems solved by technology

[0011] However, in the compressor of Patent Document 1, the thickness of the rare earth magnet is increased, and accordingly, the size of the magnetic core made of the electromagnetic steel sheet is restricted.

Therefore, the core volume of the electromagnetic steel sheet is reduced by the amount of magnet increase, and there is a problem that the magnetic force of the motor cannot be ensured.

[0012] In addition, the rotating electrical machine of Patent Document 2 has the following problems: the saturation magnetic polarization is reduced, and the necessary residual magnetic flux density cannot be ensured, so that the magnetic force of the motor cannot be ensured.

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