A linear compressor is provided that may include a shell in which a discharge port may be provided, a cylinder disposed in the shell to define a compression space for a refrigerant, a piston disposed to be reciprocated in an axial direction within the cylinder, a discharge valve disposed on or at one side of the cylinder to selectively discharge the refrigerant compressed in the compression space, a valve spring coupled to the discharge valve to provide a restoring force, and a stopper coupled to the valve spring to restrict deformation of the valve spring. The stopper may include a guide recessed in a direction in which the valve spring is deformed to reduce an impulse between the stopper and the valve spring.

Various embodiments of the present disclosure are directed to reciprocating compressors. In one example embodiment, a reciprocating compressor is disclosed including a cylinder, a piston, at least one suction valve, at least one pressure valve, at least one connection chamber, a sequence valve, a sequence valve control unit, and an unloader. The piston moves back and forth in the cylinder in order to form a compression chamber in the cylinder. The at least one suction valve and the at least one pressure valve are provided on the compression chamber. The at least one connection chamber having a connection chamber volume, which is connected to the compression chamber via at least one overflow opening. The sequence valve opens and closes the at least one overflow opening, and the sequence valve control unit controls the sequence valve. The unloader is actuated by an electrically controllable actuator.

A linear compressor may include a shell, a cylinder provided in the shell to define a compression space for a refrigerant, a frame to fix the cylinder to the shell, a piston reciprocated within the cylinder, a discharge valve disposed on or at one side of the cylinder, a discharge cover coupled to the frame and having at least one chamber to reduce pulsation of the refrigerant discharged through the discharge valve, and a valve spring disposed on the discharge cover to provide a restoring force to the discharge valve. The discharge cover may include a cover body having a discharge hole, through which the refrigerant discharged through the discharge valve may be discharged outside of the discharge cover, and a guide passage defined in the cover body to guide at least a portion of the refrigerant discharged through the discharge valve into the at least one chamber.

A linear compressor is provided that may include a shell in which a discharge port is provided, a cylinder disposed in the shell to define a compression space for a refrigerant, a piston disposed to be reciprocated in an axial direction within the cylinder, a discharge valve disposed on or at one side of the cylinder to selectively discharge the refrigerant compressed in the compression space, the discharge valve including an insertion protrusion, and a valve spring coupled to the discharge valve to provide a restoring force to the discharge valve. The valve spring may include a spring body having a central portion defined at a portion corresponding to a center of the cylinder, and an insertion hole defined in the spring body. The insertion hole may be coupled to the insertion protrusion of the discharge valve. The central portion of the spring body may be spaced apart from a central portion of the insertion hole.

An apparatus and method for sensing the position of a piston in a valve in a gas compressor or the position of a piston in a free piston engine. The apparatus includes a plurality of valve sensors, a plurality of magnets, and a plurality of valve sense modules coupled to the valve sensors and a controller coupled to the plurality of valve sense modules. The method includes processing information received from the valve sensors to determine the linear position of the valves in the gas compressor or a piston in a free piston engine.

A linear compressor includes a cylinder that defines a compression space for a refrigerant, a frame that fixes the cylinder to a shell, a piston that axially reciprocates in an interior of the cylinder, a discharge valve that is provided in front of the cylinder to selectively discharge the refrigerator compressed in the compression space for the refrigerant, a discharge cover that is coupled to the frame and has a discharge space for the refrigerant discharged through the discharge valve, a valve spring that provides an axial resilient force to the discharge valve while supporting the discharge valve, and a valve support device that is coupled to the valve spring and supported by the frame to deliver vibration generated by the discharge valve to the frame.

A particle filled neck brace is used for immobilizing the neck of a patient and includes a single handedly operable vacuum hand pump disposed on the neck brace, which pump is communicated to the interior of the neck brace. After the neck brace is secured around the neck of the patient, the vacuum hand pump is manipulated to remove air from the neck brace to form a rigid mold about the patient's neck. The vacuum hand pump has a one way directional valve so that the neck brace remains in a rigid configuration for as long as the neck brace is applied to the patient. The vacuum hand pump also includes a plurality of springs which assist the user in completing a vacuum pump cycle. To release the neck brace, the user opens a release valve which allows ambient air to refill the neck brace and increase its flexibility.

A reciprocating compressor includes: a cylinder forming a cylinder chamber; an intake valve disposed around the cylinder chamber; a movable part including either an intake valve seat configured to seat the intake valve or a back member located on an opposite side of the intake valve from the intake valve seat, and configured to move in an axial direction of the cylinder; and an actuator for moving the movable part in the axial direction to change a movable range of the intake valve between the intake valve seat and the back member.

An air compression apparatus includes an air tank, an air compressor, and a governor. The air compressor delivers compressed air to the air tank by using power of an engine at the time of load running and stops the delivery of the compressed air to the air tank at the time of no-load running. The governor switches between the load running and the no-load running of the air compressor. Furthermore, the governor changes, when an engine speed is equal to or more than a threshold value, switchover timing for switching the air compressor from the no-load running to the load running in comparison with a time when the engine speed is less than the threshold value.

A shutoff valve (2) which is switchable in a cycled manner for capacity regulation by temporarily shutting off the intake gas feed is designed as a multi-element ring valve, and is directly actuated by means of an electromagnet (12). The actuating forces for switching the shutoff valve (2) may be kept small via pressure compensation from the intake gas feed (3) to behind the anchor plate (9).