A pump device includes a rotary motor, a compartment for insertion of a disposable pump part, and one or more pulsation-reduction elements. The disposable pump part includes an input port, an output port, and a dual-action reciprocating assembly. The input port is configured for intaking fluid. The output port is configured for outputting the fluid. The dual-action reciprocating assembly is configured for pumping the fluid. The assembly includes a single piston and a rod configured to be coupled to the rotary motor, so as to drive the piston. The one or more pulsation-reduction elements are configured to reduce a pulsation in the outputted fluid, caused by the single-piston dual-action reciprocating assembly.

A silencer is equipped with a hollow tubular portion in which a discharge flow passage is formed that communicates on one end side thereof with a discharge port of a fluid pressure device (ejector) through which a pressure fluid is discharged, a cap member attached to another end part of the tubular portion, a sound absorbing member attached to an inner wall surface of the tubular portion, and a plurality of discharge ports adapted to discharge the pressure fluid, which has passed through the discharge flow passage in an axial direction of the tubular portion, in radial directions perpendicular to the axial direction.

Compressor head fixing device, a compressor and a refrigeration device. The compressor head fixing device includes a cylinder block and a cylinder head cover, the cylinder head cover being connected to the cylinder block by a fastener, the cylinder block being provided with a compression chamber and an assembly hole configured to fix the fastener; a noise reduction chamber, provided on the cylinder block; and a communication passage, provided in the cylinder block and the cylinder head cover, and being in communication with the assembly hole, the noise reduction chamber and the compression chamber. The compressor head fixing device has a compact structure, a length of the exhaust passage is shortened and the exhaust pressure is reduced.

An air compressor comprises a compressor that compresses introduced air and a tank that stores the compressed air generated by the compressor. The air compressor also comprises a discharge pipe from which the compressed air and a condensate in the tank are discharged to an outside of the tank. The air compressor also comprises a drain cock that is disposed in a passage of the discharge pipe and serves to open and close the discharge pipe. The air compressor also comprises a discharge pipe end portion that includes a discharge port facing upward at a tip end of the discharge pipe. The air compressor also comprises a tubular cover including a top portion that covers the discharge pipe end portion from above.

A pump device includes a rotary motor, a compartment for insertion of a disposable pump part, and one or more pulsation-reduction elements. The disposable pump part includes an input port, an output port, and a dual-action reciprocating assembly. The input port is configured for intaking fluid. The output port is configured for outputting the fluid. The dual-action reciprocating assembly is configured for pumping the fluid. The assembly includes a single piston and a rod configured to be coupled to the rotary motor, so as to drive the piston. The one or more pulsation-reduction elements are configured to reduce a pulsation in the outputted fluid, caused by the single-piston dual-action reciprocating assembly.

A compressor is configured to compress a fluid. The compressor includes a first casing and at least one first pipe. The first casing is electrically conductive. The at least one first pipe is electrically conductive. The at least one first pipe is fixed to the first casing with a first insulator interposed therebetween.

A muffler comprising a hollow cavity enclosed by a first bottom surface, a second bottom surface and a side wall, the side wall connects the first bottom surface with the second bottom surface, an air inlet at one end of the hollow cavity and an air outlet at the other end of the hollow cavity; the cavity is divided into a plurality of chambers in an axial direction, the chambers comprise a first chamber adjacent to the first bottom surface, a second chamber adjacent to the second bottom surface and an intermediate chamber located between the first chamber and the second chamber, the air inlet is in gas communication with the intermediate chamber, and the air outlet is in gas communication with the first chamber.

A silencer for vacuum pumps which allows only for unidirectional flow and which reduces the noises caused by the air discharged at the exhaust of said pump. The silencer features baffles to divert and disrupt the flow and an umbrella check valve to ensure the unidirectionality of the discharge flow.

A system for attenuating sound comprises an air compressor with an inlet, the inlet in fluid communication with an ambient environment. An inlet conduit extends from the inlet to the ambient environment, and an expansion volume is in fluid communication with the inlet conduit. A throttling valve or pressure relief valve is located between the expansion volume and the ambient environment, the throttling valve configured to regulate the flow of sound waves from the expansion volume, thereby attenuating the sound from the air compressor entering the ambient environment.

A pump device includes a rotary motor, a compartment for insertion of a disposable pump part, and one or more pulsation-reduction elements. The disposable pump part includes an input port, an output port, and a dual-action reciprocating assembly. The input port is configured for intaking fluid. The output port is configured for outputting the fluid. The dual-action reciprocating assembly is configured for pumping the fluid. The assembly includes a single piston and a rod configured to be coupled to the rotary motor, so as to drive the piston. The one or more pulsation-reduction elements are configured to reduce a pulsation in the outputted fluid, caused by the single-piston dual-action reciprocating assembly.