A centrifuge system includes a centrifuge and a feed line fluidly connected to centrifuge with the centrifuge driven by a hydraulic system. The hydraulic system includes an electric motor driving a hydraulic pump connected to a fluid reservoir with the hydraulic pump providing hydraulic fluid to one or more hydraulic motors which in turn rotate the centrifuge. The system includes a pressure sensor for measuring fluid pressure and a speed sensor for measuring the rotational speed of the centrifuge. A controller can be in communication with the hydraulic system and the sensors and can receive measurements from the sensors and adjust the pressure of hydraulic fluid flowing to the one or more hydraulic motors to maintain a rotational speed of the centrifuge based on differing loads. The system can include one or more valves, controlled by the controller, which can also adjust the hydraulic pressure of the system.

A system includes a source that provides air, a first compressor stage that receives the air from the source and is configured to compress the air to a first pressure, and a second compressor stage that receives the air from the first compressor stage and is configured to compress the air to a second pressure. The system also includes a first component, a second component, valves that control flow of the air, and a controller that is configured to control the valves according to a first control mode, in which the air is supplied to the first component by the first compressor stage, and a second control mode, in which the air is supplied to the second component by the second compressor stage.

A decompression system is configured to: determine a regulating amount of a flow regulating valve provided on a discharge flow path through which compressed gas flowing out from a gas generating device flows, the regulating amount being determined based on a pressure detected by a pressure sensor provided on the discharge flow path; correct the determined regulating amount based on a temperature detected by a temperature sensor provided on the discharge flow path; and control the flow regulating valve so that the regulating amount thereof becomes the corrected regulating amount.

A decompression system is configured to: determine a regulating amount of a flow regulating valve provided on a discharge flow path through which compressed gas flowing out from a gas generating device flows, the regulating amount being determined based on a pressure detected by a pressure sensor provided on the discharge flow path; correct the determined regulating amount based on a temperature detected by a temperature sensor provided on the discharge flow path; and control the flow regulating valve so that the regulating amount thereof becomes the corrected regulating amount.

The present invention relates to a hydraulic pump system including a variable displacement pump that generates an outlet pressure. The hydraulic pump system also includes a control system that decreases a displacement volume of the variable displacement pump in response to an increase in the outlet pressure and increases a displacement volume of the variable displacement pump in response to a decrease in the outlet pressure.

The present invention relates to a hydraulic pump system including a variable displacement pump that generates an outlet pressure. The hydraulic pump system also includes a control system that decreases a displacement volume of the variable displacement pump in response to an increase in the outlet pressure and increases a displacement volume of the variable displacement pump in response to a decrease in the outlet pressure.

A vacuum exhaust apparatus capable of accurately and rapidly adjusting the pressure in an exhaust chamber and a vacuum pump used therein are provided. A vacuum pump includes a rotor that rotates to exhaust an exhaust chamber and a casing having an inlet port. A valve is located between the inlet port of the vacuum pump and an outlet port of the exhaust chamber. A controller performs control such that the pressure in the exhaust chamber matches a target value. The controller adjusts the opening degree of the valve when the absolute value of the difference between the pressure in the exhaust chamber and the target value is greater than a predetermined value, and adjusts the rotational speed of the rotor of the vacuum pump when the absolute value of the difference between the pressure in the exhaust chamber and the target value is less than the predetermined value.

A multi piston machine includes a rotor, pistons, a first control valve, and a second control valve. The pistons abut against a cam surface with multiple lobes. The machine is switchable between at least three non-zero displacement volumes using the first and the second control valves. The first control valve is connected to a first and a third fluid chamber. The second control valve is connected to a second and a fourth fluid chamber. The first and the second control valve are connected to first and the second working port respectively. A third number of second control openings is twice a second number of the lobes. There is a first and a second group of the second control openings. Adjacent second control openings belong to a different first or second group. The second control openings of the first group are either connected to the first or the second fluid chamber.

An inlet valve system (10), as may be used for a cylinder chamber (20) of a compressor, such as a reciprocating compressor, is disclosed. A plurality of inlet valves (250) is movable between an open position and a closed position. The plurality of inlet valves is arranged between an unloader chamber (120) and a cylinder chamber (20) of the compressor. A control valve (270, 270′) is coupled to a controller (300) and is movable between a first position and a second position to close the inlet valves. A check valve (260, 260′) is movable between a first position and a second position to open the inlet valves. The check valve and the control valve are respectively fluidly coupled to a control chamber (252), which is decoupled from any pressure control external to cylinder chamber (20).

An inlet valve system (10), as may be used for a cylinder chamber (20) of a compressor, such as a reciprocating compressor, is disclosed. A plurality of inlet valves (250) is movable between an open position and a closed position. The plurality of inlet valves is arranged between an unloader chamber (120) and a cylinder chamber (20) of the compressor. A control valve (270, 270′) is coupled to a controller (300) and is movable between a first position and a second position to close the inlet valves. A check valve (260, 260′) is movable between a first position and a second position to open the inlet valves. The check valve and the control valve are respectively fluidly coupled to a control chamber (252), which is decoupled from any pressure control external to cylinder chamber (20).