Unique apparatuses, methods, and systems of opposing, limiting, and/or preventing undesired or un-commanded compressor rotation are disclosed. One exemplary embodiment is an HVACR system comprising a variable frequency drive configured to drive an electric motor to rotate a screw compressor or scroll compressor. A controller is configured to monitor various aspects of the system and to control the drive. When a condition indicative of potential undesired or un-commanded compressor rotation is identified, the controller commands the variable frequency drive to control the motor to limit and preferably prevent compressor rotation. One technique comprises shorting switches of the drive to a DC bus rail to allow back EMF induced current in the motor windings to be dissipated through winding resistance thus providing a damping force. Another technique comprises controlling the inverter to insert a DC current into the motor to cause the motor to align to and hold a particular position.

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.

In order to improve a refrigerant compressor, including a compressor unit having a compressor housing and at least one compressor element that is arranged in the compressor housing, for compressing refrigerant, and further including a drive unit having a drive housing and an electric motor that is arranged in the drive housing and connector terminals that are arranged on the drive housing, for the electric motor, and further including an electronic functional unit, such that the connection between the refrigerant compressor and the electronic functional unit is achievable as simply as possible, it is proposed that the connector terminals should be provided in a housing that is arranged on the drive housing, and that an electronic functional unit which performs at least one compressor function should be provided in the housing.

A rotary compressor includes a cylinder having a cylinder chamber and bush groove, a piston housed in the cylinder chamber, a blade formed with the piston to separate the cylinder chamber into low and high pressure chambers, and a pair of bushes. The bushes are fitted in the bush groove with flat surfaces facing each other to hold the blade. The flat surface of at least the bush on the low-pressure side has a crowned portion starting from a position closer to the back pressure space than a swing center position, and extending toward an edge of the bush closer to the cylinder chamber. The swing center position is where a gap between the blade and the bush is constant while the piston rotates eccentrically.

The present disclosure describes a load/unload control method for a compressor system with a rotating compressor connected to a pressure vessel. In the method, the present operating state can be monitored on the basis of a monitored/estimated electrical quantity of the compressor system, The method comprises an identification phase and an operational phase. In the identification phase, the compressor is operated at a constant rotational speed to generate two known pressures to the pressure vessel. At least one electrical quantity is monitored, and values of the electrical quantity corresponding to the pressure limits are stored. In the operational phase, reaching of a pressure limit may then be detected by comparing the present value of the monitored electrical quantity to the stored values.

The present disclosure describes a load/unload control method for a compressor system with a rotating compressor connected to a pressure vessel. In the method, the present operating state can be monitored on the basis of a monitored/estimated electrical quantity of the compressor system, The method comprises an identification phase and an operational phase. In the identification phase, the compressor is operated at a constant rotational speed to generate two known pressures to the pressure vessel. At least one electrical quantity is monitored, and values of the electrical quantity corresponding to the pressure limits are stored. In the operational phase, reaching of a pressure limit may then be detected by comparing the present value of the monitored electrical quantity to the stored values.

A scroll compressor, includes: a pressure container; a frame including a hollow cylindrical portion and a bottom surface portion formed integrally with each other, the hollow cylindrical portion having an outer peripheral surface fixed to an inner peripheral surface of the pressure container; an orbiting scroll including a first base plate and a first spiral tooth formed on one surface of the first base plate, the orbiting scroll being rotatable in a hollow portion of the hollow cylindrical portion; a fixed scroll including a second base plate with a second spiral tooth, the second spiral tooth being meshed with the first spiral tooth; and a second suction pipe communicating with the hollow portion of the hollow cylindrical portion.

A scroll compressor, includes: a pressure container; a frame including a hollow cylindrical portion and a bottom surface portion formed integrally with each other, the hollow cylindrical portion having an outer peripheral surface fixed to an inner peripheral surface of the pressure container; an orbiting scroll including a first base plate and a first spiral tooth formed on one surface of the first base plate, the orbiting scroll being rotatable in a hollow portion of the hollow cylindrical portion; a fixed scroll including a second base plate with a second spiral tooth, the second spiral tooth being meshed with the first spiral tooth; and a second suction pipe communicating with the hollow portion of the hollow cylindrical portion.

A hydraulic pump is described, comprising at least one inlet duct for a fluid, at least one outlet duct for the fluid and at least one pumping unit interposed between the inlet and outlet ducts. At least one multifunction valve is interposed between the inlet duct, upstream of the pumping unit, and the outlet duct, downstream of the pumping unit, which valve is configured to divert the flow of fluid from the inlet duct to the outlet duct without the fluid flowing into the pumping unit. The multifunction valve comprises a valve body that defines an inner bypass channel in which a shutter element is axially movable, an actuator member operatively associated with the shutter element and configured to move it from a closing position to an opening position of the bypass channel, and an elastic contrast element operatively associated with the shutter element and configured to keep it in the first closing position of the bypass channel when such shutter element is not actuated by the actuator member. The actuator member consists of a bias spring manufactured with a shape memory alloy, configured to move the shutter element from the first closing position to the second opening position of the bypass channel when a predefined temperature value is reached.

A hydraulic pump is described, comprising at least one inlet duct for a fluid, at least one outlet duct for the fluid and at least one pumping unit interposed between the inlet and outlet ducts. At least one multifunction valve is interposed between the inlet duct, upstream of the pumping unit, and the outlet duct, downstream of the pumping unit, which valve is configured to divert the flow of fluid from the inlet duct to the outlet duct without the fluid flowing into the pumping unit. The multifunction valve comprises a valve body that defines an inner bypass channel in which a shutter element is axially movable, an actuator member operatively associated with the shutter element and configured to move it from a closing position to an opening position of the bypass channel, and an elastic contrast element operatively associated with the shutter element and configured to keep it in the first closing position of the bypass channel when such shutter element is not actuated by the actuator member. The actuator member consists of a bias spring manufactured with a shape memory alloy, configured to move the shutter element from the first closing position to the second opening position of the bypass channel when a predefined temperature value is reached.