The present disclosure describes a load/unload control method for a compressor system with a rotating compressor connected to a pressure vessel. In the method, the present operating state can be monitored on the basis of a monitored/estimated electrical quantity of the compressor system, The method comprises an identification phase and an operational phase. In the identification phase, the compressor is operated at a constant rotational speed to generate two known pressures to the pressure vessel. At least one electrical quantity is monitored, and values of the electrical quantity corresponding to the pressure limits are stored. In the operational phase, reaching of a pressure limit may then be detected by comparing the present value of the monitored electrical quantity to the stored values.

A pump is provided, which includes: an internal housing inside which a vane rotor is housed; a pump housing 1 in which the centre of rotation of the vane rotor is immovable and the internal housing is able to move; a first control oil chamber which causes the internal housing to move in a direction of decreasing the discharge volume; and a second control oil chamber which causes the internal housing to move in a direction of increasing the discharge volume; a pressure adjustment valve; a temperature-sensitive valve; and an elastic member which elastically impels the internal housing. A flow passage area of the temperature-sensitive valve changes gradually with change in oil temperature, and the pressure adjustment valve changes a discharge volume in accordance with increase in pressure of the discharge oil.

A hydraulic pump is described, comprising at least one inlet duct for a fluid, at least one outlet duct for the fluid and at least one pumping unit interposed between the inlet and outlet ducts. At least one multifunction valve is interposed between the inlet duct, upstream of the pumping unit, and the outlet duct, downstream of the pumping unit, which valve is configured to divert the flow of fluid from the inlet duct to the outlet duct without the fluid flowing into the pumping unit. The multifunction valve comprises a valve body that defines an inner bypass channel in which a shutter element is axially movable, an actuator member operatively associated with the shutter element and configured to move it from a closing position to an opening position of the bypass channel, and an elastic contrast element operatively associated with the shutter element and configured to keep it in the first closing position of the bypass channel when such shutter element is not actuated by the actuator member. The actuator member consists of a bias spring manufactured with a shape memory alloy, configured to move the shutter element from the first closing position to the second opening position of the bypass channel when a predefined temperature value is reached.

A fluid supply device for a transmission of a motor vehicle. The fluid supply device comprises at least one fluid supply device housing. At least one pump and at least one electric motor are integrated in the fluid supply device housing. The fluid supply device is configured in a modular fashion.

A pump device 1 includes a relief valve 42 having a ball 45 and a valve seat 44. The valve seat 44 has a ring-shaped seat surface 52 having a wide portion 52a and a narrow portion 52b on which the ball 45 is seated. Upon valve opening, the ball 45 is pressed in a valve opening direction by a pressing force F1 according to a pressure P of working fluid while being pressed against the wide portion 52a. The ball 45 rolls on the seat surface 52 upon the valve opening while continuing or keeping contact with the wide portion 52a. At this time, the ball 45 is stably held with the ball 45 contacting the wide portion 52a of the seat surface 52. Noise of the relief valve 42 caused by vibration of the ball 45 is therefore suppressed.

An arrangement of a variable capacity vane pump for an automobile is provided that includes a pump housing having an outlet and inlet. A pump control ring is provided having a cavity. The control ring is positioned within the housing to move about a pivot. A vane pump rotor is positioned within the cavity of the pump control ring. A position of the pump control ring determines an offset between a center of the pump control ring cavity and an axis of rotation of the vane pump rotor. Vanes are provided that are driven by the rotor and which engage an interior surface of the pump control ring. The vanes and the engaged surface defining working fluid chambers. A first control chamber is provided. The first control chamber is exposed to a first side of the pivot between the pump housing and the outer surface of the pump control ring. The first control chamber is operable to receive pressurized fluid to create a force to move the pump control ring to reduce a volumetric capacity of the pump. A second control chamber, positioned between the pump inlet and outlet is provided that provides a hydraulic force to increase the volumetric capacity of the pump.

A control device that controls a target vacuum pump including a motor, including: a decision unit that decides, using at least one of target state quantities at a time of a past stop process of the target vacuum pump or another vacuum pump wherein the target state quantities are state quantities which fluctuate in accordance with a load at a time of a process of stopping a vacuum pump, a normal fluctuation range or a normal time fluctuation behavior of the target state quantity at the time of the stop process; and a control unit that controls the motor, wherein the control unit compares the target state quantity at the time of the process of stopping the target vacuum pump with the normal fluctuation range or the normal time fluctuation behavior, and changes a method of controlling the motor during the stop process depending on the comparison result.

The present disclosure relates to a compressor having a first rotor and a second rotor disposed within a housing, where the first rotor is configured to rotate about a first axis of the housing and the second rotor is configured to rotate about a second axis of the housing. The first rotor and the second rotor engage with one another such that rotation of the first rotor and the second rotor pressurizes a vapor within the housing. The compressor includes an end plate coupled to a discharge end of the housing, where the end plate includes a variable opening configured to discharge a flow of the vapor from the housing. The end plate also includes a first movable member and a second movable member that are configured to increase or decrease a cross-sectional area of the variable opening to adjust the flow of the vapor.

A positive-displacement compressor having an automatic system for adjusting compression ratio and designed for installation in a conditioning or refrigeration system for a fluid includes a suction chamber for sucking the fluid with a variable suction pressure, a delivery chamber for delivering the fluid with a delivery pressure greater than the suction pressure, a compression chamber interposed between the suction chamber and the delivery chamber and communicating with the delivery chamber via one or more discharge ports, a compression element to compress the fluid to the compression pressure, a motor driving the compression element, and an adjusting system of the compression ratio. The adjustment system includes a mechanical valve interposed between the compression chamber and the delivery chamber that automatically varies discharge port apertures in response to a pressure differential between delivery chamber and compression chamber to instantaneously equalize compression and and delivery pressure and improve compressor efficiency.

One embodiment of a pump may include an idler gear having a plurality of idler gear teeth extending radially outward, wherein at least one of the idler gear teeth may be formed with an idler gear cavity therein. The pump may include a drive gear having a plurality of drive gear teeth extending radially outward that may be intermeshed with the idler gear teeth during use. The drive gear may be formed with a recess at on axial end thereof, and the axial position of the recess may correspond to the axial position of the idler gear cavity. In one embodiment of a pump, each idler gear tooth may be formed with an identical idler gear cavity at the same relative position on each idler gear tooth.