A linear compressor is provided. The linear compressor may include a frame coupled to a cylinder, a gas hole defined in the frame, and a gas pocket that communicates with the gas hole and transfers a refrigerant gas to the cylinder.

A linear compressor is provided that may include a shell, a cylinder accommodated into the shell and defining a compression space for a refrigerant, a frame to which the cylinder may be fixed, a piston that reciprocates within the cylinder in an axial direction and compresses a refrigerant supplied to the compression space, a discharge valve that discharges the refrigerant compressed in the compression space, a discharge cover coupled to the frame and defining a discharge space in which the refrigerant discharged from the compression space by opening of the discharge valve may be collected, a valve spring that supports the discharge valve, and a support integrally formed with the valve spring by insert injection molding and coupled to the discharge cover. The valve spring may define one or more holes filled with a molding liquid used to form the support in the insert injection molding of the support.

A rear housing includes a first passage extending from an accommodation chamber towards a communication hole of a valve-forming plate. A cylinder block includes a connection portion to be connected to an external device, an outlet space opening towards the connection portion, and a second passage extending from the outlet space towards the communication hole of the valve-forming plate. A discharge passage includes a discharge chamber, the accommodation chamber, the first passage, the communication hole, the second passage, and the outlet space. The flow passage area of the communication hole is larger than at least one of the flow passage area of the first passage and the flow passage area of the second passage. The discharge passage can be designed with high flexibility.

Disclosed is an air compressor (10) for supplying compressed air to a pneumatic system in a motor vehicle. The air compressor (10) comprises a crankcase (46), a cylinder housing (14) connected to the crankcase, a cylinder head (20), a crankshaft (40) rotatably mounted in the crankcase, a cylindrical piston (12) that is connected to the crankshaft (40) by a connecting rod (42). In order to load the compressed air with as little heat as possible, the crankcase (46), the cylinder housing (14), the cylinder head (20), and the piston (12) are made of aluminum or an aluminum alloy, and the at least one piston ring (54) or the at least one oil ring is made of gray cast iron or polytetrafluoroethylene (PTFE).

A reciprocating compressor includes a cylinder that defines a compressing space and a discharge muffler configured to receive refrigerant compressed in the cylinder and to discharge the refrigerant. The discharge muffler includes a discharge muffler body and a discharge guide supported by the discharge muffler body. The discharge muffler body defines a discharge space configured to receive the refrigerant from the cylinder and includes a wall protruding from an inner circumferential surface of the discharge muffler body. The discharge guide is coupled to the wall and includes a pipe that defines a pipe inflow hole configured to receive the refrigerant from the discharge space and a pipe outflow hole configured to discharge the refrigerant. The discharge guide further includes a fixing bracket that couples the pipe to the discharge muffler body.

The labyrinth piston compressor comprises a cylinder, a piston disposed in the cylinder, and a piston rod, wherein the piston rod extends in a longitudinal direction (L) and is connected to the piston, and wherein the piston is reciprocally movable in the longitudinal direction (L) within the cylinder, wherein the cylinder comprises a first cylinder cover, wherein an inlet valve and an outlet valve are arranged in the first cylinder cover, and wherein the inlet valve and the outlet valve are arranged symmetrically with respect to a plane of symmetry (S) extending in the longitudinal direction (L) along the piston rod.

A nitriding layer (13) is formed on the front surface side of a base material of a cylinder block (7) including an opening side end surface (7B) and each cylinder hole (12). Then, a piston sliding surface (12A) of each cylinder hole (12) is formed as a compound layer-removed hole (17) by removing a compound layer (16) that is located on the front surface side of the nitriding layer (13) by using polishing means such as, for example, honing and so forth. Further, a compound layer-removed surface (18) is formed on a part (A) where a compound layer-removed hole (17) and a cylinder inlet side tapered surface (12B) of each cylinder hole (12) intersect by using the polishing means such as, for example, the honing and so forth. This compound layer-removed surface (18) is formed as a tapered-state inclined surface of an angle α.

A fluid end assembly of a hydraulic fluid pump includes a housing having a first housing bore and a second housing bore offset axially from the first housing bore. A plate is fastened to the housing. The plate has a first plate bore axially aligned with the first housing bore and a second plate bore axially aligned with the second housing bore. A first removable valve cover closes the first housing bore and a second removable valve cover closes the second housing bore. A first retainer engages the first plate bore and abuts the first removable valve cover and a second retainer engages the second plate bore and abuts the second removable valve cover.

A compressor, which includes a cylinder block and a piston assembly arranged inside the cylinder block; the piston assembly comprises a first piston, a second piston arranged inside the first piston, and a movable assembly connected to the first piston, and the movable assembly is configured to drive the first piston and the second piston to reciprocate; the cylinder block is provided with a first compression chamber that defines a space for the first piston to move up and down; the cylinder block is provided with a gas storage chamber for storing the gas after the first compression, and the gas storage chamber is connected to the first compression chamber; and the cylinder block is also provided with a second compression chamber that defines a space for the second piston to move up and down, and the second compression chamber is connected to the gas storage chamber.

For rotary protection of an external force piston of a power brake pressure generator of a hydraulic vehicle power braking system, axially parallel rotary protection grooves are provided at a circumference of an external force cylinder bore in a hydraulic block of a hydraulic unit of the vehicle power braking system, and tabs of the external force piston protrude into the rotary protection grooves.