Presented herein are systems and methods for attenuating certain pulsations in a hydraulic system comprising a pump and a hydraulic actuator. In certain aspects, an accumulator comprising an internal volume that is divided into a working chamber and a contained chamber may be utilized to at least partially attenuate propagation of certain pulsations in the system. The working chamber may be fluidically coupled to the pump via a first flow path and fluidically coupled to a chamber of the actuator via a second flow path. The system may be designed such that a first inertance of the first flow path is greater than a second inertance of the second flow path. Additionally or alternatively, the system may be designed such that a resonance associated with the first inertance and a compliance of the accumulator may occur at a resonance frequency of less than 90 Hz.

A wool-like fiber member that has high permeability and low absorbability is disposed around a discharge port of a discharge pipe that is configured to discharge condensate and compressed air stored within a tank.

The pump has a casing accommodating a piston and a driving part. The casing has a first casing member having a driving part retaining portion retaining the driving part, a second casing member fixedly stacked on the first casing member in the reciprocating direction of the piston, and a cylindrical pump chamber peripheral wall member disposed around a head of the piston. The second casing member has an end wall portion extending in a transverse direction substantially perpendicular to the reciprocating direction. A pump chamber, a delivery chamber, and a buffer chamber are defined between the first casing member and the end wall portion of the second casing member. The pump chamber, the delivery chamber, and the buffer chamber are disposed side-by-side in the transverse direction.

Presented herein are systems and methods for attenuating certain pulsations in a hydraulic system comprising a pump and a hydraulic actuator. In certain aspects, an accumulator comprising an internal volume that is divided into a working chamber and a contained chamber may be utilized to at least partially attenuate propagation of certain pulsations in the system. The working chamber may be fluidically coupled to the pump via a first flow path and fluidically coupled to a chamber of the actuator via a second flow path. The system may be designed such that a first inertance of the first flow path is greater than a second inertance of the second flow path. Additionally or alternatively, the system may be designed such that a resonance associated with the first inertance and a compliance of the accumulator may occur at a resonance frequency of less than 90 Hz.

A device for canceling acoustic noise generated includes, in one example, an inlet channel configured to be fluidly connected to an inlet port of a pump and an outlet channel configured to be fluidly connected to an outlet port of the pump. The device also includes an inlet resonator and an outlet resonator, both having open ends and closed ends. The open ends of the inlet and outlet resonators are fluidly connected to the inlet and outlet channels, respectively. When in operation, the inlet and outlet resonators can cancel noise generated by the operation of the pump.

The present disclosure relates to reciprocating compressor. The present invention can prevent friction loss or abrasion between a cylinder and a piston, which is caused when a hydraulic bearing is blocked with a foreign substance, by preventing the foreign substance mixed in refrigerant gas from flowing into the hydraulic bearing, and can improve compressor performance by preventing a specific volume in a compression space from increasing when high-temperature refrigerant gas discharged in the compression space is cooled, such that vibration noise of the compressor can be reduced since a gas guiding part offsets vibration and the noise generated when a refrigerant is discharged in the compression space. Furthermore, the number of vibrations of a mover is increased and a driving operation for removing foreign substances is carried out to increase the number of vibrations of a cylinder such that any foreign substance stuck in a gas hole can be cleaned, thereby increasing performance and reliability of the compressor.

A linear compressor includes a casing, a back cover supported in the casing, an intake flow path member coupled to the back cover, and an intake muffler of which at least a portion linearly reciprocates inside the intake flow path member. The intake flow path member includes a first hole that is formed in a front surface and is penetrated by the intake muffler, and a flow path guide that extends axially forward from a rear surface and has an opened front and an opened rear. A noise of a refrigerant passing through the intake flow path member can be reduced through an expansion space between the flow path guide and an inner surface of the intake flow path member.

A mechanism for limiting vibration amplitudes in a pumping system includes a plurality of pendulum absorbers coupled with a carrier and each having a pivoting range. The pendulum absorbers each further include a first and a second contact surface that contacts an outer peripheral surface of the carrier at limit stop positions, and each having a shape that is conforming with a shape of the outer peripheral surface. The pumping system may be used for pumping liquid nitrogen.

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.

A hydraulic pump includes: a valve plate including a suction port and a delivery port; a valve cover to which the valve plate is mounted; and a cylinder block that slides on the valve plate. The valve cover includes a suction passage and a delivery passage. The valve cover includes: a first chamber that communicates with the delivery passage through a communication passage and functions as a Helmholtz resonator; and a second chamber that communicates with the delivery passage, or with the first chamber, through an introduction passage including a restrictor. In the valve cover and the valve plate, a supply passage extends from the second chamber to a bottom dead center-side sealing surface of the valve plate, the bottom dead center-side sealing surface being a surface located between the suction port and the delivery port. The supply passage includes a restrictor.