An oil pump includes a rotor, an outer peripheral member accommodating the rotor, a first plate, and a second plate. A discharge passage through which hydraulic fluid is discharged is connected to a discharge port of the first plate. A first pressure gradually-changing groove and a second pressure gradually-changing groove are formed such that a second flow passage area is larger than a first flow passage area, the first flow passage area being a flow passage area of the first pressure gradually-changing groove of the first plate, at a position at which the first pressure gradually-changing groove communicates with a transfer chamber passing through a sealed region, and the second flow passage area being a flow passage area of the second pressure gradually-changing groove of the second plate, at a position at which the second pressure gradually-changing groove communicates with the transfer chamber passing through the sealed region.

A check valve provided makes it possible to operate a vane pump smoothly even at the start of the vane pump by maintaining an oil pressure in backpressure oil passages inside the vane pump while the vane pump is stopped. The check valve opens at the point in time when an oil pressure control device, to which a working fluid is supplied from the vane pump, has been filled with the working fluid and the oil pressure in discharge oil passages communicating with the oil pressure control device has risen and exceeded the oil pressure in the backpressure oil passages. Thus, the check valve is prevented from opening and closing repeatedly, so that the durability of the check valve is improved.

The invention provides a pump comprising a pump inlet, a pump outlet, at least two threaded rotors and a pressure controlled valve, the pressure controlled valve being capable of controlling re-circulation of fluid from the pump outlet to the pump inlet. The pressure controlled valve can be a control valve. The invention also provides a multiple stage pump assembly comprising at least two pumps arranged in series, wherein at least one of the pumps is the aforementioned pump.

A rotary piston machine includes a casing and a rotor assembly, each with a hypotrochoidal. The rotor assembly includes apices that conform to the hypotrochoidal profile of the casing, and the relative motion of the casing and the rotor assembly create variable volumes. The variable volume allows the rotary piston machine to function as a compressor, an expander, an internal combustion engine, a positive displacement pump, or a fluid-driven motor.

An eccentric movable vane pump includes a cylinder body, a first rotor, second rotors, and movable vanes of which the number is greater than or equal to 2. The first rotor is eccentrically disposed with the second rotors. One end of each of the movable vanes is rotatably connected to the first rotor, and the other ends of the movable vanes are rotatably connected to the second rotors. The first rotor is disposed on a main shaft. The cylinder body is provided with a fluid inlet and a fluid outlet respectively corresponding to an expansion area and a compression area of a space between adjacent movable vanes. The pump has a simple structure, high efficiency, low cost, multiple operation conditions, high stability, and a long service life, can operate in a high-speed/ultra-high speed range without being sealed by an elastic device, and has a small radial impact in operation.

A scroll compressor includes a movable scroll, a fixed scroll having a suction passage, a suction pipe, and a suction check valve to open and close an open end of the suction pipe. The suction check valve includes a valve body, a valve seat, and a compression spring to bias the valve body toward the open end of the suction pipe. The valve body includes a first bottom portion, and a first circumferential wall extending toward the valve seat along a peripheral portion of the first bottom portion. The valve seat includes a second bottom portion, and a second circumferential wall extending toward the valve body along a peripheral portion of the second bottom portion. One of the first and second circumferential walls has an outside diameter smaller than an inside diameter of an open end of the other one of the first and second circumferential walls.

Disclosed is a fluid circulating apparatus in which a reservoir, a valve part, and a pump part are integrated with one another, and the valve part and the pump part are disposed in the reservoir to thus achieve a compact structure, thereby achieving a reduced overall size and stabilizing a fluid circulation when pumping a fluid through a plurality of flow paths.

A pump may generally include a frame including a reservoir. The reservoir stores a hydraulic fluid. The pump may also include a motor assembly supported by the frame and a pump assembly operably driven by the motor assembly. The pump assembly is in fluid communication with the reservoir and configured to dispense the hydraulic fluid out of the frame. The pump assembly includes a first piston and a second piston, wherein the first piston dispenses hydraulic fluid out of the frame between a first pressure and a second pressure greater than the first pressure, and the second piston dispenses hydraulic fluid out of the frame between the first pressure and a third pressure, the third pressure being greater than the second pressure.

An X-ray inspection apparatus is used for an inspection of a substrate, and the X-ray inspection apparatus includes an image acquisition unit that acquires a plurality of tomographic images for the substrate, an image extraction unit that extracts, from a data set obtained based on the plurality of tomographic images, an inspection tomographic image that is a target for determining whether the substrate is acceptable or not, a saved data generation unit that generates predetermined saved data including at least the inspection tomographic image, and a saved data storage unit that stores the saved data.

A metering distribution assembly and a coating system. The metering distribution assembly includes a volumetric cavity pump that comprises a flow passage plate having flow passages, a nozzle plate with a flow passage, a gear fixing plate attached between the flow passage plate and the nozzle plate, and a gear set located in an aperture of the fixing plate. The gear set has a fluid inlet and a fluid outlet on a side of the gear set opposite to the fluid inlet. The fluid inlet is in fluid communication with the flow passages of the flow passage plate, and the fluid outlet is in fluid communication with the flow passage of the nozzle plate. A part of the flow passages of the flow passage plate, which is in direct fluid communication with the fluid inlet, extends in a direction parallel to a rotation axis of the gear set.