Disclosed are a variable capacity compressor operation mode determination method and device, a variable capacity compressor and an air conditioner. The variable capacity compressor operation mode determination method includes: detecting a current value of a compressor at present as A1 before switching an operation mode of the compressor; detecting the current value of the compressor at present as A2 after switching the operation mode of the compressor and reaching a preset time; comparing A1 and A2, determining that the switching of the operation mode of the compressor is successful when a ratio relationship between A1 and A2 satisfies a preset condition, and determining that switching of the operation mode of the compressor is failed when the ratio relationship between A1 and A2 dissatisfies a preset condition.

Disclosed are a variable capacity compressor operation mode determination method and device, a variable capacity compressor and an air conditioner. The variable capacity compressor operation mode determination method includes: detecting a current value of a compressor at present as A1 before switching an operation mode of the compressor; detecting the current value of the compressor at present as A2 after switching the operation mode of the compressor and reaching a preset time; comparing A1 and A2, determining that the switching of the operation mode of the compressor is successful when a ratio relationship between A1 and A2 satisfies a preset condition, and determining that switching of the operation mode of the compressor is failed when the ratio relationship between A1 and A2 dissatisfies a preset condition.

A pump device, that supplies a liquid reserved in a reservoir to a first liquid supply destination and a second liquid supply destination, includes: a first pump whose suction port and discharge port are not switched between at forward rotation and at reverse rotation; a second pump whose suction port and discharge port are switched each other between at forward rotation and at reverse rotation; a power source that optionally switches a rotation direction of the power source; a shaft member that is rotated by a driving force from the power source; and a control device that controls at least a rotation direction of the power source. Further, the first pump and the second pump are provided on the shaft member, the first pump is connected to the first liquid supply destination, and the second pump is connected to the second liquid supply destination.

A compressor drive system is arranged to selectively operate a compressor and engine of a drill rig. The compressor drive system includes a connection assembly coupled between the engine and the compressor. The connection assembly includes a ring gear arranged to be coupled to the compressor and a clutch arranged to be connected to the engine, wherein a starter is connected to the ring gear and arranged to engage the ring gear to rotate the compressor to a predetermined rotation speed before the clutch is engaged.

A system for noise and vibration management of a smoke evacuation system includes a pump that compresses air and produces a pressure differential within an airflow path. The pump may be a sealed, positive displacement pump. The system includes vibration absorption mechanisms disposed between inner and outer housings, as well as on the outside surface of the outer housing. Methods of controlling and regulating a motor of the system to preserve the lifespan of the motor and maintain consistent airflow rates throughout the smoke evacuation system include varying a supply of electrical current to the motor so that it can operate at variable performance levels. Orifices are opened and closed in order to relieve resistance pressures within the airflow path due to clogging and blockages.

A fluid system includes a variable-speed and/or a variable-torque pump to pump a fluid, at least one proportional control valve assembly, an actuator that is operated by the fluid to control a load, and a controller that establishes a speed and/or torque of the pump and a position of the at least one proportional control valve assembly. The pump includes at least one fluid driver that provides fluid to the actuator, which can be, e.g., a fluid-actuated cylinder, a fluid-driven motor or another type of fluid-driven actuator that controls a load. Each fluid driver includes a prime mover and a fluid displacement assembly. The fluid displacement assembly can be driven by the prime mover such that fluid is transferred from the inlet port to the outlet port of the pump.

A hydraulic system includes a hydraulic gear pump with a first gear having a plurality of first gear teeth and a second gear having a plurality of second gear teeth. The hydraulic system also includes a control valve and a control circuit. The control circuit controls the pump to adjust at least one of a flow in the hydraulic system to a flow set point or a pressure in the hydraulic system to a pressure set point, and concurrently establishes an opening of the control valve to adjust at least one of the flow to the flow set point or the pressure to the pressure set point. The control circuit establishes a position of a first tooth relative to a position of a second tooth to seal a fluid path from the outlet of the hydraulic gear pump to the inlet of the hydraulic gear pump.

Embodiments of the present disclosure relate to a refrigeration system that includes a compressor configured to circulate refrigerant along a refrigerant loop, a motor configured to drive the compressor, and a variable speed drive coupled to the motor and configured to supply power to the motor. The variable speed drive includes a primary winding of a step down transformer coupled to an alternating current (AC) power source, a first secondary winding of the step down transformer, where the first secondary winding is configured to supply power at a variable supplied voltage to the motor when the motor operates below a threshold voltage, and a second secondary winding of the step down transformer, where the second secondary winding is configured to supply power at a fixed supplied voltage when the motor operates at or above the threshold voltage.

A system and method for controlling a system that includes fixed speed and variable speed compressors are described. The method generally allows the system, for example, a heating, ventilating, and air condition (HVAC) system that includes fixed speed and variable speed compressors, to maximize unit modulating capability. The method allows the use of a variable speed compressor that is relatively smaller, which can lead to cost savings, easier installation, manufacturing, etc.

A fluid system includes a variable-speed and/or a variable-torque pump to pump a fluid, at least one proportional control valve assembly, an actuator that is operated by the fluid to control a load, and a controller that establishes a speed and/or torque of the pump and a position of the at least one proportional control valve assembly. The pump includes at least one fluid driver that provides fluid to the actuator, which can be, e.g., a fluid-actuated cylinder, a fluid-driven motor or another type of fluid-driven actuator that controls a load. Each fluid driver includes a prime mover and a fluid displacement assembly. The fluid displacement assembly can be driven by the prime mover such that fluid is transferred from the inlet port to the outlet port of the pump.