A liquid discharge system includes a liquid product pump having a sensor for monitoring vibrations passing through an outer casing of the liquid product pump to detect an occurrence of cavitation within the liquid product pump. A system and method for controlling the operation of a liquid product pump in an engine-driven hydraulic discharge system. The liquid product pump has a vibration sensor operable to detect cavitation within the liquid product pump and for providing an electrical vibration signal to a speed control module. The speed control module is operable to process the vibration signal and to produce an electrical speed control signal that is provided to an electronic actuator. The electronic actuator is operable to actuate a motor control lever of a variable speed hydraulic motor to adjust the operating speed of the liquid product pump.

A monitoring device is attached to a first leg portion and detects vibration generated in the first leg portion. The monitoring device includes a sensor unit including an inertial sensor, a plate for attachment of the sensor unit, a spacer in contact with the first leg portion, and a bolt for fixation, and is attached to the first leg portion by the bolt with the spacer, the plate, and the sensor sequentially stacked and the spacer is softer than the plate.

A housing structure including: a housing, a bottom of the housing being provided with a plurality of supporting feet; a supporting component disposed in the housing and configured to support a motor and a rotor of a compressor; and a connecting component, one end of the connecting component being connected to the supporting component, another end of the connecting component being connected to the housing, and a joint of the connecting component with the housing being away from the supporting feet. An air-conditioning unit and a compressor thereof are also provided.

A lower end plate includes: bolt holes through which bolts penetrate; a lower discharge valve; a lower discharge-valve accommodating recessed portion into which the lower discharge valve is accommodated; and a lower discharge-chamber recessed portion. A lower end plate cover is provided with a bulging portion. A lower end-plate cover chamber is formed by the lower discharge-valve accommodating recessed portion, the lower discharge-chamber recessed portion, and the bulging portion. Refrigerant passage holes include main refrigerant passage holes provided on the lower discharge-chamber recessed portion, and sub-refrigerant passage holes provided between the bolt hole and the lower discharge-valve accommodating recessed portion away from the lower discharge-valve accommodating recessed portion. The bulging portion is, in a cross section orthogonal to a rotating shaft, formed so as to overlap with at least a part of each of the main refrigerant passage holes and the sub-refrigerant passage holes.

A fluid machine device includes a plurality of fluid machines that discharge a fluid; a worn state detection unit that detects a worn state of the fluid machine; a pressure detection unit that measures a pressure from the fluid machines; and a control unit that controls the plurality of fluid machines. The control unit determines whether or not there is the fluid machine that is worn, and performs control to start operation of the fluid machine that is not worn when the pressure is insufficient.

A rotary compressor may include a case, a cylinder, a roller, a vane, a main bearing and a sub bearing, and a discharge passage defined in the main bearing or the sub bearing to discharge refrigerant compressed in a compression space. The discharge passage may include at least one discharge hole formed through the main bearing or the sub bearing, and at least one discharge guide groove having a first end that communicates with the at least one discharge hole and a second end that extends from the at least one discharge hole toward a contact point between the cylinder and the roller and is recessed from one surface of the main bearing or the sub bearing forming the compression space. Accordingly, an amount of refrigerant remaining in the compression space even after a discharge stroke may be reduced.

Among other things, techniques are described for predictive maintenance using vibration analysis of vane pumps. Sensor data is obtained and pre-processed the sensor data according to at least one feature extraction system. The features are extracted from the pre-processed sensor data and classified into at least one operating condition. A representation of the at least one operating condition is rendered at a device.

A shunt-enhanced compression and pulsation trap (SECAPT) for a screw compressor assists internal compression (IC), reduces gas pulsation and NVH, and improves off-design efficiency, without using a slide valve and/or a serial pulsation dampener. The SECAPT includes an inner casing (e.g., an integral part of the compressor chamber) and an outer casing (e.g., surrounding part of the inner casing near the compressor discharge port) forming at least one diffusing chamber with a nozzle and a feedback region that provides a feedback flow loop between the compressor chamber and the compressor discharge port. The SECAPT automatically compensates cavity pressure to meet different outlet pressures (hence eliminating under-compression and/or over-compression when the discharge port opens), partially recovers potential energy associated with the under-compression (UC), and traps and attenuates gas pulsations and noise before the discharge port opens.

A vacuum pump includes a pump rotor, a housing configured to house the pump rotor, and a monitoring device attached to the housing and configured to detect vibration of the housing. The housing includes first channels for causing a coolant to flow to a portion opposed to the monitoring device.

Dual- or multi-shaft vacuum pump comprising an engine, a first shaft and at least one second shaft, wherein the first shaft and the second shaft are synchronously driven by the motor via a common drive belt. The first shaft has a pumping element and the second shaft likewise has a pumping element which cooperates with the pumping element of the first shaft in order to convey a gaseous medium from an inlet to an outlet. The first shaft has a first emergency running gear and the second shaft likewise has a second emergency running gear which meshes with the first emergency running gear.