The present disclosure provides a pump body, a compressor, and a heat exchange apparatus. The pump body includes a cylinder assembly, a piston, a motion transmission structure, and a drive member. The cylinder assembly includes a cylinder. The piston is movably disposed in the cylinder. The drive member is connected to the piston through the motion transmission structure. An outer peripheral wall of the piston has a rail groove connected end to end in a circumferential direction, and the cylinder has a guide structure extending into the rail groove; or an inner surface of the cylinder has a rail groove connected end to end in the circumferential direction, and the piston has a guide structure extending into the rail groove. So that through driving of the piston by the drive member, the piston is capable of rotating relative to the cylinder while reciprocating along a rotating axis of the piston.

A compressor control apparatus and method differently compensate for a duty ratio of a control signal during a period in which the compressor performs a compression stroke and a period in which the compressor performs a suction stroke, respectively, to generate the control signal for controlling a compressor.

The present disclosure relates to a compressor including a case, a compression unit provided inside the case, and a driving unit, wherein the compression unit includes a cylinder having a compression space, a piston reciprocating inside the cylinder, a discharge cover covering the compression space, a first plenum disposed inside the discharge cover and having a discharge space and a coupling space, a second plenum disposed inside the discharge cover and defining a movement channel through which refrigerant moves, a rib disposed in the movement channel, and a communicating portion through which the discharge space and the movement channel communicate with each other, wherein the refrigerant discharged from the compression space moves along the discharge space, the communicating portion, and the movement channel, whereby pulsation caused by the discharge of the refrigerant can be reduced.

A gas booster for increasing a pressure of a gas includes a gas cylinder and a drive. The gas cylinder defines a chamber having an inlet and an outlet. A piston is actuatable within the gas cylinder to draw gas into the chamber through the inlet at a first pressure and to push the gas out of the chamber through the outlet at a second pressure that is higher than the first pressure. The drive includes an electric motor coupled to the piston of the gas cylinder by a mechanical connection to actuate the piston.

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.

A linear compressor includes a shell, a motor in the shell, a mover coupled to the motor and configured to perform a reciprocating motion in an axial direction, a cylinder disposed in the shell, a piston coupled to the mover and configured to reciprocate in the cylinder, a spring that supports the piston in the axial direction, and a spring cap inserted into an end portion of the spring. The spring cap defines a space portion that is defined inside the spring cap and has a volume separate from the inner space of the shell, and a passage portion that extends through an axial side surface of the spring cap and is configured to provide communication between the space portion and the inner space of the shell.

The piston compressor for compressing a gas having a cylinder and also including a piston, a piston rod, packing, a crosshead and a drive, wherein: the piston is disposed for movement in a longitudinal direction L inside the cylinder; the piston is connected to the crosshead by means of a piston rod; packing is disposed between the piston and the crosshead, through which packing the piston rod runs; the crosshead is driven by the drive; in addition an activatable magnetic bearing is disposed between the piston and the crosshead; the magnetic bearing can generate a magnetic force F.sub.m on the piston rod, at least perpendicularly to the longitudinal direction L; and an activation device activates the magnetic force F.sub.m generated by the magnetic bearing on the piston rod.

A system for tire inflation including a drive mechanism defining a rotational axis, including an eccentric mass that offsets a center of mass of the drive mechanism from the rotational axis along a radial vector; a pump arranged radially distal the rotational axis of the drive mechanism, including a chamber defining a chamber lumen, and a reciprocating element arranged at least partially within the chamber lumen and translatable along a pump axis; a drive coupler coupled between the drive mechanism at a first position and the reciprocating element at a second position fixed to the reciprocating element; a torque regulation mechanism; and a controller, communicatively coupled to the torque regulation mechanism; wherein the system is operable between at least a first mode and a second mode by the torque regulation mechanism in cooperation with the controller.

A magnetically coupled piston pump includes a piston, a pump body, and a set of drive magnets. The piston includes a set of piston magnets. Each piston magnet has poles arranged along a longitudinal axis of the piston, and each piston magnet is arranged in the piston so that the orientation of the poles of each piston magnet is the opposite of the orientation of each adjacent piston magnet. The piston is disposed in and permitted to move within the pump body. The set of drive magnets is arranged outside the pump body. Each drive magnet corresponds to a piston magnet, has poles arranged along the longitudinal axis, and is arranged so that the orientation of the poles is opposite the orientation of the poles of the corresponding piston magnet. A drive unit is coupled to the drive magnets for moving the drive magnets along the longitudinal axis.

In a piston including a plurality of piston rings, a state where a difference in differential pressure between the piston rings is eased is maintained even after passage of time, and the life of the piston rings is extended.

A piston includes a piston body in which a plurality of ring grooves is formed, and a plurality of piston rings respectively arranged in the ring grooves. In the piston, a leakage groove is formed on a low-pressure side surface of the ring groove, and in a state where the piston ring is abutted with the low-pressure side surface while being abutted with a cylinder, the leakage groove ensures communication between a high-pressure side space and a low-pressure side space with respect to the piston ring.