A plurality of scroll compressors with different fixed volume indexes are connected in fluid parallel circuit and configured to selectively operate to maximize isentropic efficiency at different condensing temperatures. Different quantities of scroll compressors of different volume indexes may be selected based upon typical climate or geographic location environmental conditions to attempt to maximize efficiency. A controller may selectively operate different combinations of the compressors of different volume indexes bases up load demands and condensing temperature conditions, which may be determined in a variety of ways.

The invention pertains to an eccentric screw pump with a stator-rotor system, which includes a rotor with a rotor screw and a stator with an internal thread. The stator has a support element and an elastomer part, wherein the support element encloses the elastomer part sectionally over its entire circumference. The stator-rotor system has a mechanism for adjusting the stator, which is coupled to at least one sensor for determining actual operating parameters of the stator-rotor system by means of a control unit that activates the adjusting mechanism with consideration of the actual operating parameters determined with the aid of at least one sensor.

A system includes a pump, an inlet sensor, an outlet sensor, and a controller. The pump is configured for pumping fluid in a phacoemulsification system. The inlet sensor is coupled with an inlet port of the pump and is configured to sense an inlet temperature of the fluid at the inlet port. The outlet sensor is coupled with an outlet port of the pump and is configured to sense an outlet temperature of the fluid at the outlet port. The controller is configured to take a responsive action based a difference between the inlet temperature and the outlet temperature crossing a defined threshold.

A refrigerant compressor unit, including a compressor housing and at least one compressor element that is arranged in the compressor housing, is movable by bearing and drive parts, and operates in at least one compressor chamber, at least one lubricant supply point arranged in the compressor housing for at least one of the bearing and drive parts and/or compressor element, and a lubricant supply line to the at least one lubricant supply point, wherein the lubricant supply line has a lubricant storage chamber through which lubricant flows and in which a lubricant presence sensor is arranged for detecting the presence of lubricant in the lubricant storage chamber.

The refrigerant compressor includes a compressor casing (2); an oil sump (13) arranged in the compressor casing (2); and an oil level sensor arrangement (14) configured to detect an oil level in the oil sump (13), the oil level sensor arrangement (14) including a tubular element (16) secured to the compressor casing (2) and a floating element (17) surrounding the tubular element (16) and being movably mounted with respect to the tubular element (16). The compressor casing (2) includes a passage opening (24) and dimensions of the tubular element (16), the floating element (17) and the passage opening (24) are defined to allow an insertion and a removal of the tubular element (16) and the floating element (17) into and out of the compressor casing (2) through the passage opening (24).

An electric pump provided with a pump unit configured to discharge working oil by being rotationally driven by an electric motor includes: a drive shaft configured to transmit rotational driving force from the electric motor to a rotor of the pump unit; a rotation-detection shaft provided coaxially with the drive shaft, the rotation-detection shaft being configured to be rotated together with the rotor; and a rotation detector unit configured to detect rotation of the rotation-detection shaft. The rotation-detection shaft has: an engagement portion configured to engage with the rotor; and a detection-target portion facing the rotation detector unit, and an outer diameter of the detection-target portion is set so as to be larger than an outer diameter of the engagement portion.

This disclosure is directed to systems and methods for controlling compressor motors, particularly varying the operation parameters of the motor to provide heat to a lubricant of the motor. The operation parameters include one or more of a pulse width modulation switching frequency, a pulse width modulation frequency switching pattern, or a torque/amp ratio of a drive of the compressor. The efficiency of the motor may be reduced to provide heat, with the heat improving lubricant quality and drive efficiency, to increase an overall efficiency of compressor operations. Methods may include determining a lubricant quality, and determining operational parameters that improve lubricant quality.

A board surface of a control board is disposed on an outward side of a motor in a radial direction in a posture along an axial direction. A rotation angle sensor is disposed on a rear side of a control board in the axial direction. A power supply input portion on the control board is disposed in an end portion on the rear side in the axial direction. A main body of a motor includes the control board and a wiring assembly electrically connecting a connector and the rotation angle sensor to each other. The wiring assembly includes a power supply input wiring, a sensor wiring, and a wiring holder holding the power supply input wiring and the sensor wiring.

A method for monitoring an oil-injected screw compressor configured to compress aspirated air by returning oil from an oil separator vessel (11) to a compression chamber (12) of a compressor block (30), for condensate formation in the oil circuit due to a too low compression discharge temperature (VET), determines a water inlet mass flow {dot over (m)}.sub.ein(t) and a water outlet mass flow {dot over (m)}.sub.aus(t) for a point in time t and determines generated condensate flow Δ{dot over (m)}.sub.w(t)={dot over (m)}.sub.ein(t)−{dot over (m)}.sub.aus(t) on the basis of difference formation.

A cooling circuit for a vehicle, in particular a motor vehicle, includes a pump having at least one rotor that is driven in rotation by a motor and configured to force the circulation of cooling liquid in the circuit. The at least one rotor includes at least one driving screw that is driven by the motor, and at least one driven screw that is driven by the at least one driving screw, the driving screw(s) and driven screw(s) being configured to force the circulation of cooling liquid in the circuit.