A pump assembly includes a pump unit having a centrifugal pump and a variable pump supplying pressurized flow. A fuel control assembly receives flow from the pump unit and includes at least one metering valve and at least one throttling valve. A control for the variable pump receives first and second pressure signals indicative of a pressure differential across the throttling valve, or across the metering valve/throttling valve combination, for altering operation of the variable pump in response to the pressure differential.

The present disclosure relates to a bidirectional valve design that provides for more rapid deflations/evacuation of fluid flow and in one example includes a valve body, a spindle piston movably coupled in a bore of the valve body and an electronically controllable motor that moves the spindle valve between a fluid evacuation position and a fluid fill position. In one example, the spindle piston includes piston structures on ends of a threaded rod. In another example, a mattress system is disclosed that employs the valve and a fluid source to provide quick evacuation of air from a patient support. In another example, the valve is coupled to an alternating pressure block valve which is then coupled to a patient support.

A driving power transmission device includes a fluid pressure type clutch device that transmits driving power between two shaft members, and a pump that supplies a fluid to the clutch device. The pump includes a pump that makes a pressure of sucked fluid high; a first flow passage through which the fluid according to a pressure discharged from the pump is supplied to the clutch device during a driving of the pump; a second flow passage through which the fluid discharged from the pump is held during a stop of the pump and a pressing force is applied to the clutch device by the fluid to be held; and a switching valve that is switchable between a normal mode where a discharge port of the pump communicates with the first flow passage and a locking mode where the discharge port of the pump communicates with the second flow passage.

A tire inflation system and method for a tire supported by a wheel, the tire inflation system including a pump system including a pump cavity configured to fluidly connect to the tire, an actuating element configured to actuate relative the pump cavity, a drive mechanism rotatably coupled to the wheel, the drive mechanism including a motion transformer and an eccentric mass, a valve fluidly connecting the pump cavity to a fluid reservoir; and a control system configured to operate the valve.

A method of and apparatus for controlling pressure in a process chamber having a continuous gas inlet flow and a continuous gas outlet flow comprising providing a pulsed valve at a gas outlet, a pressure gauge, and a programmable controller and varying the pulse rate of the pulsed valve, wherein either the open time or closed time, or both open and closed times, is lengthened or shortened, depending on whether the gauge pressure is above or below the programmed setpoint.

The invention is directed to a divider block assembly made from one piece of material. Traditional divider blocks require modular sections so that piston alignment can be calibrated precisely. The current invention uses replaceable pistons and sleeves that are suitable for use at high fluid pressures. The use of these pistons also allows for a single, bodied, one-piece, metal divider body, rather than the conventional multiple block divider blocks, which allows for a more efficient manufacturing method and stronger, more reliable, and more efficient lubricant dispensing system. The use of any of these aspects separately can improve performance, and not all are required in every embodiment.

A tire inflation system and method for a tire supported by a wheel, the tire inflation system including a pump system including a pump cavity configured to fluidly connect to the tire, an actuating element configured to actuate relative the pump cavity, a drive mechanism rotatably coupled to the wheel, the drive mechanism including a motion transformer and an eccentric mass, a valve fluidly connecting the pump cavity to a fluid reservoir; and a control system configured to operate the valve.

Disclosed is a differential pressure volume flow air sampler that measures temperature in a collection cavity, differential pressure between the measured ambient pressure and air pressure in a collection cavity. These parameters are used to calculate the volume air flow across a collection disk using a processor which adjusts a blower to maintain a substantially constant volume air flow through said air sampler from the surrounding atmosphere.

A driving power transmission device includes a fluid pressure type clutch device that transmits driving power between two shaft members, and a pump that supplies a fluid to the clutch device. The pump includes a pump that makes a pressure of sucked fluid high; a first flow passage through which the fluid according to a pressure discharged from the pump is supplied to the clutch device during a driving of the pump; a second flow passage through which the fluid discharged from the pump is held during a stop of the pump and a pressing force is applied to the clutch device by the fluid to be held; and a switching valve that is switchable between a normal mode where a discharge port of the pump communicates with the first flow passage and a locking mode where the discharge port of the pump communicates with the second flow passage.

The invention is directed to a divider block assembly made from one piece of material. Traditional divider blocks require modular sections so that piston alignment can be calibrated precisely. The current invention uses replaceable pistons and sleeves that are suitable for use at high fluid pressures. The use of these pistons also allows for a single, bodied, one-piece, metal divider body, rather than the conventional multiple block divider blocks, which allows for a more efficient manufacturing method and stronger, more reliable, and more efficient lubricant dispensing system. The use of any of these aspects separately can improve performance, and not all are required in every embodiment.