The bearing assembly, consisting of a stator component (S1) and a rotor component (R1), where the rotor component is adapted for a back-and-forth oscillatory movement (P, −P) relative to the stator component, whereby a number of cavities (301 and 302; 303 and 304) coordinated along the outer periphery of the rotor component and the inner periphery of the stator component, formed with an increasing volume (301 and 302) and a decreasing volume (303 and 304), respectively, during rotation of the rotor component in an initial direction (P) from an initial position (IP) and towards a final position (FP), while the cavities allow the volumes to decrease and increase during a rotational motion of the rotor component in a second direction (−P) in relation to the stator component (S1). The invention specifies that the above-mentioned bearing arrangement is to be adapted to interact with an instrument (M1) in order to determine, with the help of at least two components, the momentary position of the rotor component in relation to the stator component.

A method including: determining a cooling value; and comparing the cooling value to an activation point of a lead compressor. The lead compressor is in a tandem set of scroll compressors of a cooling system. The tandem set of compressors comprises a lag compressor. The method further includes: activating the lead compressor when the cooling value is greater than the activation point; activating the lag compressor subsequent to activating the lead compressor; and determining whether conditions exist including: an alarm associated with the lag compressor being generated, and the lead compressor being deactivated. The method further includes deactivating the lag compressor when at least one of the conditions exists in the cooling system.

A compressor is provided and includes a shell, a compression mechanism, a motor, a data module, and a compressor controller. The data module includes a data module processor and a data module memory. The compressor controller includes a controller processor and a controller memory distinct from the data module processor and the data module memory. The data module receives sensed data, stores the sensed data in the data module memory, determines a first diagnosis of the compressor based on the sensed data, and communicates the sensed data and the first diagnosis to the compressor controller. The compressor controller determines a second diagnosis of the compressor based on the sensed data and verifies the first diagnosis by comparing the first diagnosis to the second diagnosis.

A scroll pump has a tip seal between an axial end of the scroll blade of one of stationary and orbiting plate scrolls of the pump and the plate of the other of the stationary plate and orbiting plate scrolls. The scroll pump may have a ballast gas supply system and use the operation of the ballast gas supply system to assess the condition of the tip seal. Alternatively, the scroll pump may have two pressure sensors that sense pressure at two locations spaced along a compression mechanism of the pump to assess the condition of the tip seal.

A thermal energy recovery device includes: a circulating flow path connected to a heater, an expander, a condenser and a circulating pump for circulating a working medium; a bypass valve in a bypass path connecting the upstream side region and the downstream side region of the expander in the circulating flow path; a power recovery machine connected to the expander; a circulating pump sending the working medium condensed in the condenser to the heater; a cooling medium pump sending a cooling medium to the condenser; an upstream side sensor detecting the pressure/temperature of the working medium on the expander upstream side in the circulating flow path; and a controller controlling the bypass valve and the cooling medium pump. The controller opens the bypass valve after stopping the circulating pump, and drives the cooling medium pump if the pressure/temperature of the working medium on the expander upstream side exceeds a threshold.

A malfunction diagnosis apparatus for a gear motor includes a vibration sensor portion, and a diagnosis unit that determines whether or not an abnormality occurs in the gear motor based on vibration detected by the vibration sensor portion. The vibration sensor portion and the diagnosis unit are installed in the gear motor. The diagnosis unit has a control power source which supplies power to the vibration sensor portion. The vibration sensor portion outputs detected vibration data to the diagnosis unit in a digital format.

A climate-control system may include a compressor, a condenser, an evaporator, a first sensor, a second sensor, a third sensor, and a control module. The compressor may include a motor and a compression mechanism. The condenser receives compressed working fluid from the compressor. The evaporator is in fluid communication with the compressor and disposed downstream of the condenser and upstream of the compressor. The first sensor may detect an electrical operating parameter of the motor. The second sensor may detect a discharge temperature of working fluid discharged by the compression mechanism. The third sensor may detect a suction temperature of working fluid between the evaporator and the compression mechanism. The control module is in communication with the first, second and third sensors and may determine whether a refrigerant floodback condition is occurring in the compressor based on data received from the first, second and third sensors.

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.

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 method for measuring load performance of a positive displacement motor (PDM) test coupon. The test coupon comprises a partial length of a PDM stage and is received inside a sealable test chamber. In some embodiments, the test coupon may be cut from a failed PDM stage. The test chamber is filled with test fluid. In some embodiments, the test fluid may be drilling fluid sampled from a live well. Rotation of the rotor on the test coupon actuates rotation of the stator. A braking torque is applied to the stator rotation, enabling evaluation of, for example, fatigue load performance of test coupon. Additional embodiments comprise the rotor axis and the stator axis being offset in order to simulate rotor/stator eccentricity in a full size PDM stage.