A linear compressor includes a frame including a frame body, a frame head that extends from a front end of the frame body, a flange groove defined in the frame head, and a body hole that passes through the frame body; a cylinder including a cylinder body inserted into the body hole, a cylinder flange, and a cylinder head provided on a front end of the cylinder flange; and a lock ring press-fitted to be coupled to the flange groove and provided in a space defined between the cylinder head and an inner circumferential surface of the flange groove.

Disclosed is a linear compressor. The linear compressor according to the spirit of the present invention includes a cylinder forming a compression space for refrigerant and a discharge unit forming a discharge space for refrigerant into which refrigerant discharged from the compression space flows. The discharge unit includes a discharge cover having an inner space formed therein and a discharge plenum placed in the inner space. In this case, the discharge plenum includes a plenum flange extending radially, a plenum seating part, a plenum body, and a plenum extension part which extend from a radially inner side end of the plenum flange, and a plenum guide surface extending from a radially outer side end of the plenum flange toward the inner space.

The present invention relates to a linear compressor. A discharge unit of the linear compressor according to an aspect of the present invention includes a discharge cover coupled with the frame. In addition, the discharge cover includes a cover flange portion and a chamber portion. At this time, the cover flange portion includes a flange main body having a main body penetration portion and a main body extension portion provided outward in a radial direction so as to face the main body penetration portion, and a flange coupling portion having a flange coupling hole into which a fastening member for coupling with the frame is inserted.

A simple, compact, and economical motor/pump unit for supplying vacuum to a pneumatic brake booster of a motor-vehicle brake system, wherein the motor/pump unit is designed as a diaphragm pump having a single elastomeric diaphragm, which is moved by an electrically operated motor unit by an eccentric drive, and has a pump housing and a working-space cover and the diaphragm is clamped between the pump housing and the working-space cover at the radial outer edge of the diaphragm in a sealing manner and the working-space cover is designed as a multi-part working-space cover having an upper cover, a lower cover, and an inlet valve and an outlet valve, which are arranged between the upper cover and the lower cover and control the air circulation through the working space.

A linear compressor includes a frame, a cylinder disposed in the frame, a piston configured to axially reciprocate in the piston, a discharge valve disposed at a front of the piston, and a discharge cover assembly coupled to the frame and disposed at the front of the piston. The discharge cover assembly includes a discharge cover including an inner space, a first discharge plenum that is disposed in the inner space of the discharge cover and defines a first discharge space inside the first discharge plenum, and a second discharge plenum disposed between the first discharge plenum and the discharge cover. The second discharge plenum defines a second discharge space in fluid communication with the first discharge space and a third discharge space in fluid communication with the second discharge space between the first discharge plenum and the second discharge plenum.

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 may include a housing, a piston, a valve plate, a discharge valve and a head cover. The housing defines a cylinder. The piston is disposed within the housing and is movable within the cylinder. The valve plate is mounted to the housing and may include a discharge passage extending through the valve plate and defined by a discharge valve seat. The discharge valve is movable between a first position in which the discharge valve is seated on the discharge valve seat to restrict fluid flow through the discharge passage and a second position in which the discharge valve is spaced apart from the discharge valve seat to allow fluid flow through the discharge passage. The head cover may include a guide post including a pocket that receives a valve stem of the discharge valve.

A reciprocating compressor includes a cylinder (5) including a cylindrical cylinder portion (6) and a cylinder head portion (7) provided on one side of the cylinder portion, and a piston mechanism (8) reciprocably fittedly inserted on an inner peripheral side of the cylinder portion and including a piston (9) defining an inside of the cylinder portion into a compression chamber (10) and a non-compression chamber (11). A bottomed hole-shaped valve body housing portion (7B) is formed at the cylinder head portion. The valve body housing portion is opened to a piston side facing the piston in an axial direction of the cylinder portion. Further, a discharge valve unit (18) and a valve holding member (21) are provided in the valve body housing portion. The discharge valve unit is inserted in the valve body housing portion. The valve holding member holds the discharge valve unit in the valve body housing portion.

A linear compressor includes a frame including a frame body, a frame head that extends from a front end of the frame body, a flange groove defined in the frame head, and a body hole that passes through the frame body; a cylinder including a cylinder body inserted into the body hole, a cylinder flange, and a cylinder head provided on a front end of the cylinder flange; and a lock ring press-fitted to be coupled to the flange groove and provided in a space defined between the cylinder head and an inner circumferential surface of the flange groove.

An improved air compressor includes a cylinder that is fitted with a piston body and defines at its top wall a plurality of exit holes which are approximately equal in diameter and can be regulated by a resilient sheet having a plurality of branches to enable the cylinder to communicate with an air storage container. The exit holes are normally sealed by the branches of the resilient sheet with the assistance of compression springs when the air compressor is not in operation. The exit holes allow the compressed air produced in the cylinder to quickly enter the air storage container, so that the piston body can conduct reciprocating motion more smoothly and thus the performance of the air compressor can be increased.