There is provided a free rotary fluid machine including: a main body which is provided in a hollow cylindrical shape, and has an elliptical inner circumferential surface; a rotor which is provided in the main body, and rotates about the same rotation center as the main body; tip seals which are provided at one side of the rotor so as to be in contact with the inner circumferential surface of the main body; and blades which are provided between the tip seals provided adjacent to each other, and supported by the tip seals, in which the blade has one end surface that faces the inner circumferential surface of the main body, and the other end surface that is opposite to one end surface, and centers of radii of curvature of one end surface and the other end surface are positioned at the same side. As described above, a space formed among the inner circumferential surface of the main body, the rotor, and the tip seal is sealed by the auxiliary tip seal, and as a result, it is possible to reduce friction between the tip seal and the main body and to prevent a leak of an introduced working fluid.

There is provided a free rotary fluid machine including: a main body which is provided in a hollow cylindrical shape, and has an elliptical inner circumferential surface; a rotor which is provided in the main body, and rotates about the same rotation center as the main body; tip seals which are provided at one side of the rotor so as to be in contact with the inner circumferential surface of the main body; and blades which are provided between the tip seals provided adjacent to each other, and supported by the tip seals, in which the blade has one end surface that faces the inner circumferential surface of the main body, and the other end surface that is opposite to one end surface, and centers of radii of curvature of one end surface and the other end surface are positioned at the same side. As described above, a space formed among the inner circumferential surface of the main body, the rotor, and the tip seal is sealed by the auxiliary tip seal, and as a result, it is possible to reduce friction between the tip seal and the main body and to prevent a leak of an introduced working fluid.

In a scroll fluid machine, a thinned section (26) is provided in correspondence with a position at which the wrap height of a spiral wrap (15B, 16B) changes due to a step part. The thinned section (26) is provided on the front-side surface or the rear-side surface of a tooth tip section of at least one of the spiral wraps (15B, 16B) of at least one of partner scrolls (15, 16) respectively engaging with scrolls (15, 16). The thinned section (26) is provided in the direction in which the wrap thickness decreases so as to extend over at least a reduced-machining-accuracy area (27), which is an area where the machining becomes discontinuous due to at least a change in the wrap height. Thus, a contact failure between the spiral wraps (15B, 16B) is avoided in the area where the machining accuracy relatively decreases as a result of increasing the machining speed, thereby achieving both improved productivity and maintained performance.

A pump includes: a housing in which a pump chamber accommodating an inner rotor and an outer rotor is formed in a pump chamber formation surface, and an O-ring groove is formed around the pump chamber; an O-ring that is placed in the O-ring groove; and a plate that is attached to the pump chamber formation surface and closely contacts the O-ring to close the pump chamber. Inter-hole grooves connecting to an outer edge of the pump chamber formation surface are formed around the O-ring groove.

A multi-stage vacuum pump may include a sealing arrangement for sealing between the stator components of the pump. The end seals of the arrangement comprise an annular portion for sealing between end stator components and shell components and axial portions which extend from the annular portion and together with separate axial seals seal between the shell components.

A scroll compressor is provided. The scroll compressor may include a casing, a discharge cover to partition an inside of the casing into suction and discharge spaces, a first scroll, a second scroll that defines compression chambers together with the first scroll and includes an intermediate pressure discharge hole that communicates with a compression chamber having an intermediate pressure of the compression chambers, a back pressure plate that defines a back pressure chamber that accommodates a refrigerant discharged from the intermediate pressure discharge hole, a floating plate that defines the back pressure chamber together with the back pressure plate, and a gasket disposed between the back pressure plate and the second scroll and having an intermediate pressure communication hole that allows the intermediate pressure discharge hole to communicate with the intermediate pressure suction hole. The gasket may block communication between the back pressure chamber and the suction and discharge spaces.

A rotary engine includes a housing having a working cavity, a shaft, the shaft having an eccentric portion, a rotor having a first axial face, and a second axial face opposite the first axial face, the rotor disposed on the eccentric portion and within the working cavity, the rotor comprising a first cam on the first axial face, the first came having an eccentricity corresponding to the eccentricity of the eccentric portion of the shaft, and a cover integral with, or fixedly attached to, the housing, the cover comprising a plurality or rollers, each roller engaged with the cam, wherein the cam guides the rotation of the rotor as the rotor rotates within the working cavity and orbits around the shaft.

A housing for a rotary engine has: a peripheral wall defining two end faces and an inner face transverse to the two end faces; two side walls sealingly engaged to the two end faces of the peripheral wall, a core of a side wall of the two side walls having a core face, the core face having a cavity section facing the rotor cavity and an abutment section annularly extending around the cavity section, the abutment section facing an end face of the two end faces, the abutment section having a flared portion flaring away from the end face; and a coating on the core face, the coating made of a material harder than a material of the core of the side wall, the coating covering the cavity section and ending at a coating edge located on the flared portion, the coating edge free of contact with the end face.

A housing for a rotary engine has: a peripheral wall defining two end faces and an inner face transverse to the two end faces; two side walls sealingly engaged to the two end faces of the peripheral wall, a core of a side wall of the two side walls having a core face, the core face having a cavity section facing the rotor cavity and an abutment section annularly extending around the cavity section, the abutment section facing an end face of the two end faces, the abutment section having a flared portion flaring away from the end face; and a coating on the core face, the coating made of a material harder than a material of the core of the side wall, the coating covering the cavity section and ending at a coating edge located on the flared portion, the coating edge free of contact with the end face.

A block sealing of a rotary combustion engine having a rotating block with radially located cylinders and pistons and an outside stationary case is disclosed. Transverse and/or lateral sealings located in the stationary case fit tight to an outer surface of the block. In circular grooves, a lateral sealing of radius sealing strips with springs situated between adjacent transverse sealing strips placed in transverse grooves is located. Couplings with notches and pressure springs are located in bores of the stationary case for inserting radius sealing strips and transverse sealing strips. The radius sealing strip is provided with a cut-out for interlocking of a stop connected with the stationary case. In the side of the radius sealing strip, a longitudinal groove in which a flexible sealing element and/or transverse sealing strip is made, and at its side, it is provided with a groove in which another flexible sealing element is located.