Abstract: A motor has a stator having a plurality of teeth for receiving windings, a yoke connected to each tooth, and a rotor having permanent magnets facing the stator. An inner wall surface of each tooth faces the rotor with an air-gap therebetween. Each tooth is separated from an adjacent tooth by a slot-open-section extending between a tailing end of the tooth and a leading end of the adjacent tooth. The inner wall surface of each tooth has an arc extending from a center of the slot-open-section toward the tailing end. The air-gap at the tailing end of each tooth is greater than the air-gap at the leading end of each tooth. The inner wall surface of each tooth includes a straight-line tailing section extending from the center of the slot-open-section toward the leading end. The straight-line tailing section extends tangentially from the arc.

Abstract: A refrigerant compressor for use in refrigerators, air conditioners, heat pumps or the like apparatus. The refrigerant pump has a casing which encases a combination of a compressor and an electric motor. A spring guide has an attaching base portion fixed to a bearing supporting a crank shaft driven by the motor, and an oil pipe connected to the attaching base such that the inside of the oil pipe opens to one end of the crank shaft. The oil pipe is bent so that the free end thereof is immersed in the lubricating oil in the case. The oil pipe receives a closely-coiled spring which is fixed at its one end to the end of the crank shaft while the other end is immersed in the lubricating oil. As the compressor operates, the coiled spring rotates in the oil pipe so that the lubricating oil is sucked by the lead of the coiled spring through the gap formed between the inner peripheral surface of the oil pipe and the coiled spring.

Abstract: A refrigerant compressor suitable for use in refrigerators, air conditioners, heat pumps or the like apparatus. The refrigerant compressor has a closed casing which encases a driving electric motor section and a compressor section constructed as a unit. The compressor section has a substantially horizontal crank shaft consisting of a main shaft portion fixed to one end of the rotor of the driving motor, an eccentric portion rotatably carrying a rotary piston and an end journal portion. The lubrication system of this compressor has a passage means for introducing a lubricating oil to various parts requiring lubrication, and a lubricator adapted to supply the lubrication oil to the passage means. The passage means includes a peripheral oil groove formed in the portion having crank shaft of the minimum eccentricity and connected at its one end to a peripheral oil groove formed in the main shaft portion and at its other end to a peripheral oil groove in the journal portion of the crank shaft.