The present teachings generally include a rotor assembly having a plurality of rotor sheets or layers mounted to a shaft, and methods of construction for a rotor assembly. Each rotor sheet or layer in the assembly may be provided with a central opening extending between the first and second sides through which the shaft extends. In one aspect, the rotor sheets or layers can be provided with a plurality of lobes extending away from the central opening, wherein each of the lobes can have a lobe opening extending through the thickness of the sheets or layers. In one example, the rotor sheets or layers can be rotationally stacked to form a helical rotor. In one example, the rotor sheets are formed from a pre-cured composite material and are bonded together with an adhesive.

A rotor assembly having a plurality of rotor plates mounted to a shaft, and methods of construction for a rotor assembly are disclosed. Each rotor plate in the assembly may be provided with a central opening extending between the first and second sides through which the shaft extends. In one aspect, the rotor plates are provided with a plurality of lobes extending away from the central opening, wherein each of the lobes has a lobe opening extending through the thickness of the plates. In one embodiment, the rotor plates are rotationally stacked to form a helical rotor.

A screw compressor includes compressor bodies, a motor disposed in a side of the compressor bodies, a gear box coupled to the compressor bodies and transmitting the drive force of the motor to a screw rotor, and a tubular coupling casing coupling the gear box and the motor and having horizontal axis. The coupling casing has a work hole in the horizontal direction. The work hole is used for maintaining a coupling accommodated in the coupling casing. The coupling casing has a rib extending in the up-down direction. It is thus possible to avoid reduction in the rigidity of the coupling casing with no cost increase, and to improve maintainability.

A rotary engine, has: housings secured to one another, the housings including a first side housing, a second side housing, and a rotor housing disposed between the first side housing and the second side housing; and a rotor rotationally received within a rotor cavity defined by the first side housing, the second side housing, and the rotor housing; wherein the first side housing, the rotor housing, and the second side housing are cooled in parallel via respective coolant passages including: a first side housing coolant passage extending through the first side housing; a second side housing coolant passage extending through the second side housing; and a rotor housing coolant passage extending through the rotor housing, and wherein the coolant passages are free of inter-passage connection between the housings.

A rotary engine, has: housings secured to one another, the housings including a first side housing, a second side housing, and a rotor housing disposed between the first side housing and the second side housing; and a rotor rotationally received within a rotor cavity defined by the first side housing, the second side housing, and the rotor housing; wherein the first side housing, the rotor housing, and the second side housing are cooled in parallel via respective coolant passages including: a first side housing coolant passage extending through the first side housing; a second side housing coolant passage extending through the second side housing; and a rotor housing coolant passage extending through the rotor housing, and wherein the coolant passages are free of inter-passage connection between the housings.

Disclosed is a hub and a bearing which cooperate to hold a shaft in steady axial alignment with a rotor. In a preferred embodiment, the shaft is coupled to the rotor of a fluid gear pump. The gear pump is located in a pump assembly between a front cover and a rear casing. A hub receiving pocket is formed in the front cover, and the hub is connected to the front cover for receipt within the hub receiving pocket. The bearing is surrounded by the hub such that the shaft runs through the bearing to be coupled to the rotor of the gear pump. A pair of high pressure seals are located within the hub at which to surround the shaft and prevent leakage. The bearing being surrounded by the hub stabilizes the shaft to minimize wobbling in response to axial and radial loads to which the shaft is subjected while rotating.

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.

The invention proposes a vane pump (VP) with adjustable delivery volume, which vane pump has a pump housing (G), a cam ring (KR) arranged therein, and a rotor (R) which is rotatably movably mounted therein. The vane pump (VP) has a regulating device (RV) through which the delivered pressure medium (DM) flows and which has two outlets (A1, A2) which are each connected to one of two pressure chambers (DK1, DK2) in order to charge these with regulable proportions of the pressure medium (DM), wherein, to change the eccentricity of the cam ring (KR) relative to the rotor (R), the two pressure chambers (DK1, DK2) act on the outer surface of the cam ring (KR). The vane pump (VP) has two criss-crossing control ducts (STK*, STK#) which connect in each case one of the outlets (A1, A2) to one of the two pressure chambers (DK1, DK2) in order to charge these with the regulable proportions of the pressure medium (DM). The criss-crossing control ducts (STK*, STK#) are preferably arranged in a cover (D) of the pump housing such that the control ducts (STK*, STK#) are in a criss-crossing arrangement without coming into contact with one another. By means of this design, the vane pump (VP) can be easily reconfigured for a change in rotational direction of the rotor.

An oil balancing system for a multiple compressor system is provided. The oil balancing system includes an oil equalization line disposed between a first compressor and a second compressor. A first solenoid valve is provided in the oil equalization line. A first signal corresponds to a first oil level in the first compressor. A second signal corresponds to a second oil level in the second compressor. An oil balancing module uses the first signal and the second signal to diagnose an oil imbalance between the first compressor and the second compressor, and applies corrective action, whereby the corrective action includes sending control signals to operate at least one of the first compressor, the second compressor, or the first solenoid valve in a way that eliminates the oil imbalance.

The present invention relates to a fluid machine. A pump integrated expander (29A) includes a pump unit (60) and an expansion unit (50). In the pump unit (60), a casing member (65) supports a gear pump (61), a rotating shaft (28) and a driven crank mechanism (81). In the expansion unit (50), a casing including a main body (51a) and a casing member (54) supports an expander (23) including a fixed scroll (51) and an orbiting scroll (52). The pump integrated expander (29A) is divided into the pump unit (60) and the expansion unit (50) by separating at the fitted portion of a tubular portion (65c) on the pump unit (60) side and a smaller inner diameter portion (54b) on the expansion unit (50) side and by pulling the eccentric bush (83) out of a drive bearing (56).