Abstract: An outlet check valve includes an output valve seat provided at an outlet port or an outlet passage for compressed air in the vicinity of an outlet port of a compression mechanism and an outlet valve body. The valve seat and valve body are biased away from each other by a gravitational force or a spring. With this arrangement, even if a compressor is rotated at a low speed during a start-up operation, it is possible to cause stagnant liquid to undergo reverse flow into an accumulator disposed on the suction side and to store the liquid temporarily, thereby removing the liquid in the compression spaces and the suction passages and facilitating the start-up operation in a normal rotational direction. A pressure difference between the pressures upstream and downstream relative to the valve body is large when the normal rotating operation is stopped. By this pressure difference, the outlet valve body is moved to close the outlet valve seat, thereby to prevent the reverse rotation of the compression mechanism.

Abstract: A recess is provided in the wrap of a stationary scroll in the vicinity of a terminal end thereof on the side of a suction chamber, so that an orbital scroll can be prevented from collision against the stationary scroll, thereby avoiding breakage of both scroll wraps and occurrence of noises. Further, with the provision of another recess in the orbital scroll wrap in the vicinity of a terminal end thereof, the orbital scroll can be prevented from colliding against the stationary scroll, thereby preventing breakage of both scroll wraps and occurrence of noises.

Abstract: A compressor includes a communication hole 42 through which lubrication oil in an oil reservoir 5 is supplied to a back pressure chamber 39 at least through an eccentrically driving bearing 15, and a communication bore 45 or gap through which the lubrication oil in the back pressure chamber 39 is fed into compression spaces, and a constricted resistance member 44 for regulating the oil flow rate is provided on the communication hole 42. The passage resistance can be made larger in comparison with the case where resistance is caused in a small space of a sliding portion of a bearing, and an accurate value of the passage resistance can be preset with the oil flow rate being low, thereby preventing flow of the lubrication oil to the compression operating spaces from increasing in quantity. Thus, there is provided a highly reliable scroll compressor which has a high compression efficiency, consumes power constantly, and has no risk of compression of the lubrication oil in the compression operating spaces.

Abstract: A swirling spiral impeller portion 13 is structured such that a pressure between the suction and discharge pressures acts on a part of the rear surface thereof. The compressor includes a means for adjusting and cooling the intermediate pressure which acts on a part of the swirling spiral impeller portion 13 by means of the lubricant oil stored in a lubricant oil reservoir 26 to which the discharge pressure in the sealed container acts. The lubricant oil supplied to the compression portion is provided under any pressure condition, and is always supplied stably. As the lubricant oil is cooled, it does not reduce the efficiency greatly.

Abstract: In a scroll-type compressor, the revolving motion drive shaft 16, formed on the revolving end plate 12 at the side opposite to the revolving swirl blades 11, is fitted in an eccentric bearing eccentrically disposed inside of the main shaft of the crank shaft 6. The crank shaft 6 is connected to the rotor of the electric motor and is supported at the end portion thereof opposite to the main shaft by an upper bearing of a rolling type. Above the upper bearing, a rise preventing plate 24 for preventing the crank shaft 6 from excessively rising upwards is arranged in a fixed manner. The crank shaft 6 is so shaped as to have a stepped portion where the diameter of the shaft portion mounting the rotor 5 becomes stepwise greater than that of the shaft portion fitted in the upper bearing 21. Between the stepped portion and the inner race of the upper bearing 21 is provided an elastic member 26 which can be wave shaped.

Abstract: A balance weight to equilibrate an inertial force due to reciprocation of an Oldham's ring is mounted so that a vibration due to an unbalanced inertial force of the Oldham's ring is transmitted in a direction perpendicular to or almost perpendicular to a connecting direction between the closed vessel and the accumulator, whereby a vibration resulting from an unbalanced inertial force of the compressor body due to the balance weight to equilibrate the inertial force on account of the reciprocation of the Oldham's ring is increased in a direction perpendicular to or almost perpendicular to the connecting direction between the closed vessel and the accumulator. The vibration, however, is reduced in the connecting direction or in a direction close to the connecting direction. As a result, vibrations of pipes connecting the closed vessel to the accumulator are reduced, and reduction of noise of the overall air conditioning system is attained.

Abstract: The compression capacity of a rotary compressor may be changed by a cylinder bypass system. The change of compression capacity is achieved by a slide wall member which composes part of an inside wall of a cylinder containing a compression mechanism and which is movable, thereby bypassing gas being compressed to a suction side of the compressor. The slide wall member is caused to slide forward by gas pressure applied and to slide backward by a spring force. By controlling such gas pressure, the capacity of the compressor may be changed. A relatively large opening is formed in the cylinder when the slide wall member is moved backward, so that the compression capacity can be greatly reduced without a large decrease in efficiency.

Abstract: A control system for a compressor driven by a pole-changing motor comprises a pole changer for the motor, a contactor for stopping the motor for a predetermined time in case of the pole changing, and a switch responsive to the variation in a physical quantity which occurs in the compressor every time when the latter is stopped, whereby the motor is stopped in case of the pole changing and then is started again in response to the actuation of the switch. This control system is especially adapted for use in a pole-changing-motor-driven compressor used in a refrigeration cycle of an air conditioner.