Abstract:
A compressor system includes a lead compressor operable to produce a flow of compressed fluid at a first output and a lag compressor operable to produce a flow of compressed fluid at a second output. The sum of the first output and the second output defines a system output. A lead variable speed motor is operable to drive the lead compressor at a first compressor speed to vary the first output and a lag variable speed motor is operable to drive the lag compressor at a second compressor speed to vary the second output. A sensor is operable to measure a system load, and a lead motor drive is operable to control the speed of the lead variable speed motor and to set a desired operating state of the lag variable speed motor in response to a comparison of the system load and the system output.
Abstract:
A scroll-type refrigerant compressor includes a drive shaft with an off-axis lubrication conduit which is supplied with oil from an oil pan located in the lower part of the compressor by an oil pump that is disposed at a first end of the shaft. The lubrication conduit has lubrication holes at the different shaft guide bearings. The second end of the shaft is equipped with a device that enables the orbital movement of the moving scroll of the compressor. The aforementioned shaft also includes a return conduit which is inclined in relation to the axis of the shaft and which extends over at least part of the length thereof. One of the ends of the return conduit opens at the wall of the shaft in the area located beyond the rotor on the side of the oil pan. In addition, fluid communication is provided between the lubrication conduit and the return conduit.
Abstract:
A scroll-type refrigerant compressor includes a drive shaft with an off-axis lubrication conduit which is supplied with oil from an oil pan located in the lower part of the compressor by an oil pump that is disposed at a first end of the shaft. The lubrication conduit has lubrication holes at the different shaft guide bearings. The second end of the shaft is equipped with a device that enables the orbital movement of the moving scroll of the compressor. The aforementioned shaft also includes a return conduit which is inclined in relation to the axis of the shaft and which extends over at least part of the length thereof. One of the ends of the return conduit opens at the wall of the shaft in the area located beyond the rotor on the side of the oil pan. In addition, fluid communication is provided between the lubrication conduit and the return conduit.
Abstract:
An inverter-integrated or an inverter-separated electric compressor has a control device. The control device estimates a compressor suction pressure based on the temperature of the power element of the inverter, or directly measures the compressor suction pressure by a sensor, or estimates the compressor suction pressure based on a compressor suction temperature or on a compressor housing temperature. Further, the control device calculates a motor torque based on a motor rotational speed, a motor phase current, and a motor phase voltage, estimates a compressor discharge pressure based on the compressor suction pressure and the motor torque, and estimates a compressor discharge temperature based on the compressor suction pressure and the compressor discharge pressure. An electric compressor having a discharge temperature detection means in place of a conventional thermal protector can be realized.
Abstract:
The invention relates to a scroll-type refrigerant compressor The inventive compressor comprises: a sealed chamber which is defined by a ferrule (2) and which contains a suction volume and a compression volume; and an electric motor which is disposed on the suction side and which comprises a stator (7) and a rotor (8), the latter being solidly connected to a drive shaft (26). The stator (7) is surrounded by an intermediate casing (6) which defines (i) an annular volume (13) with the moving ferrule (2) of the compressor and (ii) a chamber (11) containing the coil end of the motor and facing the compression volume side. The end of the intermediate casing that faces the side opposite the compression volume is disposed at the end of the stator facing the side opposite the compression volume or set back from same. In addition, means (14) are provided in order to convey at least part of the gas arriving at the gas inlet in the ferrule into the chamber (11) containing the coil end.
Abstract:
Compressor including a housing (2) containing a compressor element (6) that is powered by a variable speed motor (7) with a control box (8) with a set maximum number of revolutions (Nmax) for the compressor element (6), an air cooling blower (10) which sucks air from the environment via an inlet (11) and blows it back to the environment through the housing (2) via an exhaust (12) and a cooling circuit (13) for the cooling of the gas which has been compressed by the compressor element (6), further wherein the control box (8) is equipped with an algorithm (24) that reduces the maximum allowed set number of revolutions (Nmax) to a defined level as soon as the monitored environmental temperature (T20) rises above a maximum set level (Tmax), and the maximum allowed set number of revolutions (Nmax) is increased as soon as the environmental temperature (T20) falls below the maximum set level (Tmax).
Abstract:
A variable speed drive is provided for operating a compressor motor in a refrigerant system. When a low load situation has been determined by the refrigerant system controls, the variable speed drive operates the compressor motor at lower speed mode of operation. Further, the operation of the variable speed drive is combined with a pulse width modulation control of different system components. In particular, at least one valve or compressor can be can be rapidly cycled by the control to regulate amount of refrigerant passing through the valve or compressor. Example valves would include a shut-off valve for an economizer cycle, an unloader valve, or a suction modulation valve.
Abstract:
A compressor includes an orbiting member and a non-orbiting member mounted relative the orbiting member to define first and second chambers disposed between the orbiting and non-orbiting members. The non-orbiting member forms a seal to generally prevent fluid communication between the first and second chambers when in a first position and breaks the seal to allow fluid communication between the first and second chambers when in a second position. A structure supports the orbiting and non-orbiting members for relative orbital movement therebetween and a time pulsed actuation apparatus is coupled to the structure and configured to selectively break the seal.
Abstract:
The present invention relates to a control system for protection against breakage of the lubricating-oil film in the bearings of hermetic compressors, as well as to a control method that has the objective of guaranteeing that a variable-capacity compressor should be maintained above a minimum rotation in order to prevent the oil film close to the respective bearing from breaking. One of the forms of achieving the objectives of the present invention is by means of a control system for protection against break of the lubricating-oil film in bearings of hermetic compressors, a microprocessor (10) actuating a set of switches (SW2M) selectively, so as to generate a rotation at the motor-compressor assembly (20, 21), the compressor (21) having a minimum rotation (RPMmin) of the compressor (21) so that the oil film will not be broken.
Abstract:
A helical screw rotor compressor adapted for working against a pressure container whose pressure P is allowed to vary between a lowest pressure P2 and a highest pressure P1, said compressor being driven by an electric motor. The electric motor is characterised by having in one operating range defined by the pressure interval P of said pressure container a quality such that halving of the torque of said motor will result an increase in motor speed of at least of 6 percent. It is also preferred that the compressor is optimised for an internal volume factor at which the pressure of the compressor will be lower than P2+0.85*(P1−P2) at the opening instance.