Systems and methods are provided for pump systems that deliver optimized performance and efficiency. A method includes selecting a pump for the pump system. A maximum operating speed of the pump is determined, and its torque requirements are evaluated. A motor is selected to meet the torque requirements and a speed target is set for the motor. A speed reducer is sized for operation of the motor at the speed target and operation of the pump below the maximum speed, and the motor is coupled with the pump through the speed reducer.

A roots blower includes driving and driven rotors that rotate while intermeshing with each other, driving and driven shafts fixed at the shaft centers of the driving and driven rotors, respectively, a driving gear attached to the end of the driving shaft, a driven gear that is attached to the end of the driven shaft and intermeshes with the driving gear, a rotor chamber that houses the driving and driven rotors, a gear chamber that houses the driving and driven gears, and driving and driven bearings that rotatably support the driving and driven shafts, respectively. The driving and driven gears are lubricated by a grease.

The present disclosure relates to a scroll compressor and its lubricating oil supply system. The lubricating oil supply system includes: an oil passage P.sub.1 formed by a core hole extending longitudinally through the crankshaft; an oil pump, whose oil suction port is immersed in the lubricating oil in the oil pool, and the oil outlet is connected to the oil circuit P.sub.1; an oil passage P.sub.3 located in the gap between the upper end surface of the crankshaft and the lower surface of the orbiting scroll; an oil passage P.sub.4 formed by a longitudinal hole in the crankshaft, the longitudinal hole extending downwards from the upper end surface of the crankshaft; an oil passage P.sub.5 formed by a transverse hole in the crankshaft and a gap between the lower edge of the hub of the orbiting scroll and the upper surface of the upper counterweight, the transverse hole extending transversely from the outer peripheral surface of the upper end of the crankshaft to communicate with the longitudinal hole, the opening of the transverse hole on the outer peripheral surface of the upper end of the crankshaft is aligned with the gap between the lower edge of the hub and the upper surface of the upper counterweight; an oil passage P.sub.6 formed by the gap between the outer peripheral surface of the hub and the upright wall of the upper counterweight, and the gap between the outer peripheral surface of the hub and the inner peripheral surface of the center hole of the housing; and an oil passage P.sub.2 formed by an oil return pipe so that the lubricating oil circulates.

A compressor includes a compression mechanism, an electric motor unit, a drive shaft and a housing. A portion of the drive shaft, which is located on one side in an axial direction, is rotatably supported by a main bearing, which is formed integrally in one-piece with or is fixed to a main bearing member of the compression mechanism. Another portion of the drive shaft, which is located on another side in the axial direction, is rotatably supported by a sub-bearing, which is formed integrally in one-piece with or is fixed to an inside of a body portion of a sub-bearing member. The sub-bearing member is formed separately from the housing and is fixed to a bottom surface of a bottom portion of the housing.

A system is provided for generating vacuum in a vehicle. The system includes a vacuum pump, an engagement clutch, an actuator, and a torque limiting clutch. The engagement clutch operatively connects a camshaft to the rotor. The actuator controls the clutch. The actuator is movable, based on air pressure in a vacuum conduit, between a low-pressure position in which the actuator causes the clutch to operatively disconnect the camshaft from the rotor, and a high-pressure position in which the actuator causes the clutch to operatively connect the camshaft to the rotor. The torque limiting clutch limits torque transfer to the rotor when the engagement clutch operatively connects the camshaft to the rotor. The system also provides control for hysteresis.

The present invention concerns a dry vacuum pump comprising: a drive device (1) comprising a drive shaft (3) at one end of which is fixed at least one drive wheel (4) provided to set in motion at least one belt (5); at least two parallel rotors (7, 8) each having a shaft (9, 10) provided with a rotor element (11, 12), this shaft (9, 10) being able to be driven in rotation by the belt (5) and being equipped at one of its axial ends with a toothed wheel (13, 14), this pump having the special features that: the drive wheel (4) and the belt (5) are smooth; each shaft (9, 10) of the rotor (7, 8) comprises at least one smooth section (16, 17) arranged to co-operate with the belt (5), and the toothed wheels (13, 14) of the shafts (9, 10) of the rotor (7, 8) are dimensioned and arranged to mesh with one another.

A compressor includes a compression mechanism, a driveshaft, and a motor. The compression mechanism is configured to compress a fluid to a discharge pressure. The motor is configured to rotate the driveshaft. The driveshaft is engaged with the compression mechanism and is fixed to rotate with at least a portion of the compression mechanism. The driveshaft includes a longitudinal aperture configured to receive the fluid at a suction pressure, and includes a flange that receives at least a portion of the compression mechanism. The flange and the compression mechanism define a fluid passage therebetween. The fluid at suction pressure is received within the fluid passage from the longitudinal aperture in the driveshaft.

Combining at least one centrifugal compression stage and at least one positive displacement compression stage in an integrally geared compressor to allow for different types of compression based on a temperature or a volume of gas to be compressed by the integrally geared compressor.

A brushless DC compressor comprising a casing, a brushless DC motor, a compression device, and a driving mechanism. The casing has a left room, a right room adjacent the left room, and a lower room. The brushless DC motor is disposed in the left room, and the compression device is disposed in the right room. The driving mechanism is disposed in the lower room, including a driving gear engaging a rotor of the brushless DC motor, a driven gear engaging a hollow shaft of the compression device and driven by the driving gear; whereby refrigerant flows into a compression space of the compression device, rotating the rotor by the stator and driving the driving gear, the driven gear, then the compression device; then being discharged from a refrigerant discharge hole and an axial groove, to form a brushless DC compressor with stronger torque and greater compression efficiency.

A positive displacement pump assembly includes a rotor housing defining a rotor cavity, and an end plate configured to at least partially close one end of the rotor cavity. Rotors are supported on and fixed to rotor shafts and extend through the rotor cavity. A first pair of bearings fixing the rotor shafts to the end plate. A second pair of bearings fixes the rotor shafts to the rotor housing, preventing relative axial movement between the rotor shafts and the rotor housing. The end plate is axially movable with the rotor shafts when the rotor shafts vary in axial length due to thermal fluctuations so that changes in an axial clearance at end faces of the rotors are reduced.