Abstract:
An apparatus for driving a compressor comprises a compressor having a compression mechanism part for sucking a fluid to compress the same, and an electric motor for driving the compression mechanism part, and an inverter device for driving the electric motor at variable speeds. The electric motor comprises a self-starting type electric motor having a rotor, which comprises a cage conductor and a polarized permanent magnet, and the inverter device comprises a plurality of semiconductor switches for controlling drive frequencies of the electric motor.
Abstract:
A control system for a cooling system includes a first sensor for sensing a property indicative of demand for cooling and a controller coupled to the sensor. The controller produces the variable duty cycle control signal in response to the property and causes the compressor and valve to vary a cooling capacity of the cooling system in response to the variable duty cycle control signal. The sensor may sense the pressure, temperature, or both. The valve may be a suction-side pressure regulator or a liquid-side expansion valve of the solenoid or stepper type.
Abstract:
A multi-stage screw compressor includes at least two stages of compression, each compressor stage including a pair of rotors driven to effect gas compression. Each compression stage is provided with independent variable speed drive means and a control unit for controlling the speeds of the independent drive means. The control unit includes processing means for processing signals generated by a plurality of devices monitoring operating parameters of the compressor, and adjusting the speed of the drive means to provide a required gas flow delivery rate and pressure, at least one of the monitoring devices monitoring the torque and at least one of the monitoring devices monitoring the speed of each drive means.
Abstract:
The engine has an input system formed with a fluid displacement pump that enables substantially continuous pumping from a low-pressure side to a high-pressure side substantially without any backflow or backpressure pulsations. The output system, in one embodiment, is an output system having a turbine rotation about an axis that is substantially orthogonal to the pressure flow originating from the prime mover. The output system may include a first turbine which provides for the mechanical work output of the engine and a second turbine which feeds back to drive the input system. Any increase in the load to be driven by the first turbine translates into a proportional increase in the drive energy fed back to the input system. In an alternative embodiment, a differential may be used to distribute the output power to a load or back to the input compressor.
Abstract:
A refrigeration system has a compressor which incorporates fluid injection into one or more of the fluid pockets. A source of fluid for injection into the pockets is attached directly to the shell of the compressor to eliminate the need for having fluid piping between the source of fluid and the compressor. The source of fluid can be a flash tank which increases the capacity and efficiency of the system or the source of fluid can be a heat exchanger which also increases the capability and efficiency of the system.
Abstract:
A motor-driven compressor includes a motor and a compression portion for compressing a refrigerant. The motor-driven compressor comprises an input terminal for the motor and a drive circuit for controlling a rotation speed of the motor. The input terminal of the motor passes through an opening formed through a wall of a refrigerant suction route, whereby the input terminal is secured to the wall, and extends beyond the wall. The drive circuit controls the rotation speed of the motor and has an output connector. The output connector of the drive circuit is connected directly to the input terminal to secure the drive circuit to the wall. The direct connection eliminates a need for a wire connection between the output connector and the input terminal. Moreover, methods of assembling motor-driven compressors are disclosed.
Abstract:
The present invention provides a variable frequency controlled refrigerant compressor in a dehydrator for compressed air or other cases. In particular, the present invention detects changes in a demand on the pneumatic air supply by monitoring a pressure of a refrigerant system associated with the air supply. Based on the changes in the refrigerant system pressure, a motor speed controller generates and sends a control signal to the variable speed compressor to adjust the speed of the variable speed compressor based on the demand in the air supply.
Abstract:
A refrigerating device including a refrigerating cycle including a plurality of compressors driven by motors, the plurality of compressors comprising a variable speed compressor which can be controlled in capacity and a constant speed compressor which is driven by a motor of which rotor core comprising a cage type conductor and permanent magnets.
Abstract:
An air-conditioner, an outdoor unit and an refrigeration device each using a refrigeration cycle which can reduce power consumption so as to be highly efficient, which can be operated by a commercially available power source, and which is highly reliable. An air-conditioner comprises a motor and a refrigeration cycle including a compressor driven by the motor, an outdoor heat-exchanger and an indoor heat-exchanger, the motor being located in a motor chamber within a closed container, and refrigerant gas in the refrigeration cycle flows through the motor chamber, wherein the motor has a core of a rotor in which a cage type conductor and permanent magnets magnetized in bipolar state are embedded, and said motor is driven by a commercially available electric power source.
Abstract:
A diagnostic system includes a controller adapted for coupling to a compressor or electronic stepper regulator valve. The controller produces a variable duty cycle control signal to adjust the capacity of the compressor or valve position of the electronic stepper regulator valve as a function of demand for cooling. The diagnostic system further includes a diagnostic module coupled to the controller for monitoring and comparing the duty cycle with at least one predetermined fault value indicative of a system fault condition and an alert module responsive to the diagnostic module for issuing an alert signal when the duty cycle bears a predetermined relationship to the fault value.