Provided are a pump body assembly and an assembly method therefor. The pump body assembly includes a first cylinder assembly (10), a second cylinder assembly (20) and a third cylinder assembly (30) sequentially arranged in a vertical direction. At least one of the first cylinder assembly (10), the second cylinder assembly (20) and the third cylinder assembly (30) is provided with a positioning detection portion (40).

A pump having an adjustable delivery volume, including: a pump housing featuring a delivery chamber which includes a delivery chamber inlet for a fluid and a delivery chamber outlet for the fluid; a delivery member, which can be rotated within the delivery chamber, for delivering the fluid; an adjusting device featuring a setting structure, which is mounted such that it can move back and forth within the pump housing in order to adjust the delivery volume of the pump, and a helical spring for applying a spring force, which acts in a setting direction, to the setting structure, wherein the windings of the helical spring are enclosed by an envelope lying on the outside of the helical spring wherein the cross-sectional area of the envelope as measured transversely with respect to the longitudinal direction of the spring changes progressively in the longitudinal direction of the spring.

Embodiments of the present disclosure include a motor controller with a processor and a machine readable medium. The medium includes instructions that, when loaded and executed by the processor, cause the processor to receive an estimated or sensed speed of a motor, extract a mechanical frequency component from the estimated or sensed speed, transform the mechanical frequency into direct quadrature (DQ) domain at the mechanical frequency, control the mechanical frequency to zero, and generate a dampening signal for torque based upon the controlled mechanical frequency.

Embodiments of the present disclosure include a motor controller with a processor and a machine readable medium. The medium includes instructions that, when loaded and executed by the processor, cause the processor to receive an estimated or sensed speed of a motor, extract a mechanical frequency component from the estimated or sensed speed, transform the mechanical frequency into direct quadrature (DQ) domain at the mechanical frequency, control the mechanical frequency to zero, and generate a dampening signal for torque based upon the controlled mechanical frequency.

A crankshaft assembly, a compressor and a refrigeration device are provided. The crankshaft assembly has an eccentric shaft component, a spindle component and a main screw oil pump. The eccentric shaft component has an eccentric cavity, and the spindle component has a first cavity communicated with the eccentric cavity. A first through-hole and a second through-hole in a first spindle are each communicated with the first cavity. An outer surface of the first spindle is provided with a first spiral oil groove connecting the first through-hole and the second through-hole. An outer surface of the main screw oil pump is provided with a second spiral oil groove along its length direction, and a spiral direction of the second spiral oil groove is opposite that of the first spiral oil groove.

A pump technology that provides for more effective and efficient transfer of liquids, such as petroleum products and components, to and through pipelines. Such a technology can comprise a type of external gear pump that creates higher flow, resulting in higher pressures in the pipeline, to move the liquids, while providing for longer pump life, simpler and less maintenance, and fewer undesired conditions, with a smaller footprint, in a cost-effective system. Further, one or more portions of the pump can be configured to be easily replaceable to provide for maintenance in place, and provide for longer pump life. Additionally, one or more portions of the pump can be constructed with or coated with abrasive resistant material that extends the life of the external gear pump. Such material can also reduce the friction between surfaces and improve the life of the external gear pump under poor feeding conditions.

Aspects described herein relate generally to rotary compressors that incorporate a flywheel within to significantly reduce the compressor vibration and drive torque ripples as well as to achieve a higher overall electro-mechanical efficiency and potentially lower combined costs of BLDC rotary compressors and their drive electronics.

Aspects described herein relate generally to rotary compressors that incorporate a flywheel within to significantly reduce the compressor vibration and drive torque ripples as well as to achieve a higher overall electro-mechanical efficiency and potentially lower combined costs of BLDC rotary compressors and their drive electronics.

A compressor may include first and second scrolls, an axial biasing chamber, and a modulation control valve. The second scroll includes an outer port and an inner port. The outer and inner ports may be open to respective intermediate-pressure compression pockets. The modulation control valve may be in fluid communication with the inner port, the outer port, and the axial biasing chamber. Movement of the modulation control valve into a first position switches the compressor into a reduced-capacity mode and allows fluid communication between the inner port and the axial biasing chamber while preventing fluid communication between the outer port and the axial biasing chamber. Movement of the modulation control valve into a second position switches the compressor into a full-capacity mode and allows fluid communication between the outer port and the axial biasing chamber while preventing fluid communication between the inner port and the axial biasing chamber.

A mobile pump system for pumping water for extinguishing with an auxiliary agent, and a method therefor. The mobile pump system includes a frame for housing the pump system, a booster pump arranged in the frame, a metering pump arranged in the frame for the purpose of adding an auxiliary agent to a water flow, and a drive configured to drive the booster pump and the metering pump. The metering pump is provided with a displaceable metering pump frame and coupling means for connecting the metering pump to a container of the auxiliary agent.