Abstract: A scroll-type fluid machine includes an orbiting scroll member and a stationary scroll member each of which has an end plate and a spiral wrap protruding upright therefrom. The scroll members are assembled together such that their wraps mesh with each other. Closed spaces are defined by the wraps and end plates of both scroll members, and are progressively moved towards the center of the scroll members while decreasing their volumes in accordance with an orbiting movement of the orbiting scroll member. The edges of the projecting end of the wrap of each scroll member are chamfered. Also, steps are formed in conformity with the configuration of each spiral wrap on respective corners of the groove bottom between adjacent turns of the wrap. The chamfered edges of the projecting end of the wrap of each scroll member faces the steps on the groove bottom of the opposing scroll member, respectively, when the scroll members are assembled together.

Abstract: A scroll compressor including a stationary scroll and an orbiting scroll, with an intermediate pressure chamber being defined on a back side of the orbiting scroll member and being in communication with a pressure chamber through a communication hole to produce a force for pressing the orbiting scroll against the stationary scroll. Oil in an oil sink is supplied to sliding portions by a differential pressure between a pressure in the air tight container and a pressure in the intermediate pressure chamber. A valve is provided for switching the connection of the intermediate pressure chamber to a higher intermediate pressure side or to a lower intermediate pressure side of the compressor.

Abstract: A scroll fluid apparatus including a fixed scroll member and an orbiting scroll member each having an end plate and a wrap, the two scroll members being maintained in meshing engagement with each other with the respective wraps facing inwardly to allow the orbiting scroll member to move in orbiting movement with respect to the fixed scroll member without rotating on its own axis. The fixed scroll member is formed with a discharge port at its central portion and a suction port at its outer peripheral surface to draw a gas by suction through the suction port and allow same to flow in a sealed space defined between the two scroll members and reducing its space during operation to thereby compress the gas and discharge the compressed gas through the discharge port.

Abstract: Disclosed is a scroll-type fluid machine which has an orbiting scroll member and a stationary scroll member each having an end plate and a spiral wrap protruding upright therefrom. The scroll members are assembled together such that their wraps mesh with each other to form therebetween closed chambers of volumes which are progressively decreased as the chambers are moved toward the centers of the scroll members as a result of an orbital movement of the orbiting scroll member with respect to the stationary scroll member. The machine is suitable for use as a refrigerant compressor in a refrigeration system. A fluid check valve is disposed in the refrigerant gas suction passage connected to the suction side of the machine, so as to prevent any reversing of the orbiting scroll member. A passage is formed to provide a communication between a suction chamber defined by the scroll members and another closed chamber.

Abstract: A scroll-type fluid machine having an orbiting scroll member and a stationary scroll member each having an end plate and a spiral wrap of at least two turns protruding upright from one of the sides of the end plates. The orbiting scroll member has a back pressure chamber formed on the back side thereof and communicating with the compression spaces of the fluid machine through pressure equalizing ports formed in the orbiting scroll member, so that the pressure of the fluid under compression is introduced to the back pressure chamber to produce an axial thrusting force for pressing the orbiting scroll member towards the stationary scroll member. The positions of the pressure equalizing ports in terms of the wrap angle .lambda. of the wraps are selected to meet the following condition:.lambda.d>.lambda.>.lambda.d-2.pi.,where, .lambda.d represents the wrap angle of the wraps when the volume of the compression spaces is minimized. The equalizing ports are positioned at .lambda. and .lambda.+2 .pi..

Abstract: In a sealed type scroll compressor including an intermediate pressure chamber in which a pressure intermediate in magnitude between a discharge pressure and a suction pressure prevails, a bearing device including a roller bearing and a plain bearing mounted on a frame for supporting a shaft section of a crankshaft. To reduce application of unsymmetrical load to the bearings and prevent an increase in a bearing friction loss, the roller bearing is located in a position close to a crank section of the crankshaft and the plain bearing is located in a position remote from the crank section.

Abstract: A scroll-type compressor has an orbital scroll member and a stationary scroll member each having a disc-shaped end plate and a spiral wrap protruding upright from the end plate. The scroll members are assembled together with their wraps meshing with each other to define compression chambers therebetween. The orbital scroll member executes an orbital movement without rotating around its own axis. A discharge port and a suction port are formed in a central portion and a peripheral portion of the end plate of the stationary scroll member, respectively. As the orbital scroll member makes the orbital movement, the compression chambers are moved towards the center while decreasing their volumes thereby to progressively compress a gas drawn through the suction port and to discharge the compressed gas through the discharge port.

Abstract: A sealed type electrically operated compressor including a sealed container, and a pair of scroll members in the sealed container each having an end plate and a spiral wrap located in upright position thereon. The orbiting and the stationary scroll members are assembled with the respective wraps facing inwardly and meshing with each other, and the orbiting scroll member is rotated by an electric motor to move in orbiting movement to compress fluid in compression spaces defined by the two scroll members and discharge compressed fluid into a space in the container. A suction pipe defining a suction passage for the fluid to be led therethrough into the compression spaces extends at one end portion through the end plate of the stationary scroll member to open in a suction space defined by the two scroll members and extends at the other end portion through a wall of the sealed container axially to communicate with external equipment on the lower pressure side.