Provided is an internal gear pump in which a casing and a cover can be easily positioned to each other when the casing and the cover are assembled, and they can be prevented from separating or falling off. In an internal gear pump 1, at least one of a casing 5 and a cover 6 is a molded body of a resin composition and the like. The casing 5 and the cover 6 are fixed with a plurality of protrusion parts protruding from one of the casing 5 and the cover 6 fitted in the other. The protrusion parts protrude from the casing of metal bushes 9 fixed to the casing 5, and the casing 5 and the cover 6 are integrated by bolts 13 passing through the metal bushes 9 across these two members.

A refrigeration cycle apparatus includes a refrigerant and a refrigeration cycle circuit. The refrigeration cycle circuit includes a heat exchanger and a compressor, and circulates the refrigerant. The refrigerant is a single hydrofluoroolefin (HFO)-based refrigerant or a mixed refrigerant. In the mixed refrigerant, an HFO-based refrigerant is mixed at a mixing ratio of 10% by weight or more. The compressor includes a motor. The motor includes a resin component. The resin component includes a polyimide having a terminal blocked with a terminal group.

A gear configured to rotate as a unit with a shaft, the gear includes: a plurality of annular grooves formed on both side surfaces of the gear in a direction of a rotation axis of the shaft, at least partially overlapped when viewed from the direction of the rotation axis, and at least partially overlapped in a radial direction with respect to the rotation axis.

There is provided a shoe capable of suppressing deformation of a member on which the shoe slides. The shoe includes: a first sliding surface which slides on a concave surface of a piston (first movable member); and a second sliding surface which bulges toward a side opposite to the first sliding surface and slides on a flat surface of a swash plate (second movable member). The second sliding surface includes: a curved outer peripheral portion which is provided along an outer periphery of the second sliding surface; and a central portion which is provided at a center of the second sliding surface so as to be continuous with the curved outer peripheral portion and has a radius of curvature greater than a radius of curvature of the curved outer peripheral portion.

The present disclosure provides an oil pump including a housing in which a space is formed, a rotor installed to be rotatable in an eccentric position in the housing and having vanes mounted along a circumference direction to be protruded and retracted in a radial direction of the housing, and an inner ring fitted to an inner surface of the housing and rotated along with the rotor when the rotor rotates. The housing is formed of a material harder than the material of the inner ring, and oil for lubrication is provided between the housing and the inner ring.

A fixed scroll member includes a fixed base and a spiral fixed tooth member mounted to the fixed base. An orbiting scroll member is made of a resin material and includes an orbiting base arranged to face the fixed base; and a spiral orbiting tooth member. A housing is configured to house the fixed scroll member and the orbiting scroll member with the fixed scroll member being fixed thereto. An orbiting slide surface is located to be radially outside of the orbiting base of the orbiting scroll member, and a housing slide surface is formed on a portion of the housing. The portion is made of a metal material and is arranged to face the orbiting slide surface. The orbiting slide surface is in slidable contact with the housing slide surface. The portion of the housing has an outer wall exposed to atmospheric air.

A gear pump includes: an inner rotor having external teeth; an outer rotor having a tubular inner housing portion in which the inner rotor is rotatably housed in an eccentric state, and internal teeth meshing with the external teeth; a first core having a tubular rotor housing portion in which the inner and outer rotors are housed, and a flange portion projecting radially outward from a tube wall of the rotor housing portion; a board-shaped second core having a contact portion in contact with the flange portion in an axial direction, and closing an opening of the rotor housing portion; and a housing opposing the second core and made of a resin. A gap is formed between opposing surfaces of the second core and the housing in a state where the flange portion is in contact with the contact portion and the housing opposes the second core.

A cylinder block includes a metal body part having a cylinder, and an outer wall part made of fiber reinforced resin, surrounding an outer circumference of the body part. A part of the outer wall part at BDC side in a cylinder axis direction contacts a bottom wall forming part. The outer wall part is comprised of an inner layer surrounding the outer circumference of the body part, and an outer layer surrounding an outer circumference of the inner layer. A density of reinforcing fiber contained in the outer layer is higher than that in the inner layer. A thickness of a part of the inner layer at BDC side in the cylinder axis direction is greater than that of the TDC-side inner layer. A thickness of a part of the outer layer at TDC side in the cylinder axis direction is greater than that of the BDC-side outer layer.

A vane pump includes: a casing forming a pump chamber therein; a rotor arranged inside the casing to rotate eccentrically with respect to the casing; and a plurality of vanes configured to rotate with the rotor and slide on an inner side surface of the casing. At least one of Formula (1): I(b/a)k and Formula (2): I(c/a)j is satisfied, where a represents a height of the pump chamber, b represents a height of the rotor, c represents a height of the vane in a rotation axis direction of the rotor, and where I represents a linear expansion coefficient of the casing in the rotation axis direction, k represents a linear expansion coefficient of the rotor in the rotation axis direction, and j represents a linear expansion coefficient of the vane in the rotation axis direction.

A piston for a heavy duty diesel engine including a composite layer forming at least a portion of a combustion surface is provided. The composite layer has a thickness greater than 500 microns and includes a mixture of components typically used to form brake pads, such as a thermoset resin, an insulating component, strengthening fibers, and an impact toughening additive. According to one example, the thermoset resin is a phenolic resin, the insulating component is a ceramic, the strengthening fibers are graphite, and the impact toughening additive is an aramid pulp of fibrillated chopped synthetic fibers. The composite layer also has a thermal conductivity of 0.8 to 5 W/m.Math.K. The body portion of the piston can include an undercut scroll thread to improve mechanical locking of the composite layer. The piston can also include a ceramic insert between the body portion and the composite layer.