Abstract: A compressor includes a motor driven by a controller and having a rotor and a stator, a compressing unit driven by the motor in a hermetic container in which refrigerant is filled. Driving the motor at a low rpm, the controller practices a feedback control which determines a timing of turning on/off switching elements based on a signal detecting a position of the rotor, and when the motor is driven at a high rpm, the controller practices an open-loop control which outputs a given frequency and drives the motor synchronizing with the given frequency. This structure achieves a compressor working with a fewer noises in PWM driving.

Abstract: A compressor includes a motor driven by a controller and having a rotor and a stator, a compressing unit driven by the motor in a hermetic container in which refrigerant is filled. Driving the motor at a low rpm, the controller practices a feedback control which determines a timing of turning on/off switching elements based on a signal detecting a position of the rotor, and when the motor is driven at a high rpm, the controller practices an open-loop control which outputs a given frequency and drives the motor synchronizing with the given frequency. This structure achieves a compressor working with a fewer noises in PWM driving.

Abstract: A compressor includes a compressing section accommodated in a hermetic container and a motor section, coupled to the compressing section, for driving the compressing section. The motor section has a bored section on an end of the compressing section side and a motor having two rotor poles and including a rotor core in which permanent magnets are buried. The compressing section includes a bearing made of non-magnetic material and extending inside the bored section. This structure reduces both of loss torque due to magnetic attraction between an inner wall of the bored section and the bearing, and eddy-current-loss in the bearing, so that a highly efficient compressor is obtainable.

Abstract: A sealed compressor for use in a refrigerator includes a sealed housing having an interior communicated to the outside of the sealed housing through a discharge tube, a compressor element accommodated within the sealed housing, an electric element accommodated within the sealed housing for driving the compressor element, and a coupling tube fluid-connecting the compressor element and the discharge tube within the sealed housing. To avoid a resonant motion of the coupling tube which would otherwise generate obnoxious noise, an inverter controller is employed to allow the electric element to be operated at one of a plurality of frequencies other than the resonance frequency of the coupling tube.

Abstract: A hermetic terminal cover is arranged to be mounted onto a hermetic terminal of, such as, a closed-type compressor. The hermetic terminal cover has terminal caps for covering respective terminal strips of the hermetic terminal. Each terminal strip includes a terminal pin fixedly passing through a metallic base with an insulator interposed therebetween. The terminal caps are mutually connected by flexible ribs each having a curved shape, and preferably an arc shape. Accordingly, each terminal cap has a high degree of positional or displacement freedom to facilitate mounting of the terminal cap onto the corresponding terminal strip. Further, each terminal cap has an increased thickness at a portion corresponding to an exposed surface of the insulator holding the terminal pin. Accordingly, adverse affection of metallic powders, such as, generation of short circuits and sparks between the terminal pins and the metallic base is effectively prevented.