A method of operating an exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit lined to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target (step SI), wherein when the motor speed is within the predetermined target then; determining if a motor torque is within a predetermined target (step S2) wherein when the motor torque is within the predetermined target then; determining if a motor temperature is within a predetermined target (step S3) wherein when the motor temperature is within the predetermined target then; maintaining operation of the exhaust gas recirculation pump.

A compressor includes two parallel arranged primary cylinders and a secondary cylinder arranged in the downstream of the two primary cylinders. The secondary cylinder includes a cylinder body and a sliding vane. The sliding vane is arranged inside the cylinder body. A locking part is used for locking and unlocking the sliding vane. The locking part is clamped with and separated from the sliding vane. When the sliding vane is in the locking position, the sliding vane is locked in a seal cavity inside the secondary cylinder, and the locking end of the locking part extends to the side at which the secondary cylinder is located. The compressor can be switched between a single-stage mode and a double-stage mode. In the condition of light load, energy efficiency can be improved and the waste of energy sources is avoided. An air conditioning system and compressor control method are also disclosed.

The present invention relates to a pumping system to generate a vacuum (SP), comprising a main vacuum pump which is a dry screw pump (3) having a gas suction inlet (2) connected to a vacuum chamber (1) and a gas discharge outlet (4) leading into a gas evacuation conduit (5) in the direction of a gas exhaust outlet (8) outside the pumping system. The pumping system comprises a non-return valve (6) positioned between the gas discharge outlet (4) and the gas exhaust outlet (8), and an auxiliary vacuum pump (7) connected in parallel to the non-return valve. In a pumping method by means of this pumping system (SP), the main vacuum pump (3) is started up in order to pump the gases contained in the vacuum chamber (1) and to discharge these gases through its gas discharge outlet (4), simultaneously to which the auxiliary vacuum pump (7) is started up. Moreover the auxiliary vacuum pump (7) continues to pump all the while that the main vacuum pump (3) pumps the gases contained in the vacuum chamber (1) and/or all the while that the main vacuum pump (3) maintains a defined pressure in the vacuum chamber (1).

A motor-driven compressor includes an electric motor driven by a motor driver, which includes a switching element that converts DC voltage from a battery to AC voltage. A temperature detector detects the temperature of the switching element. A voltage detector detects DC voltage applied to the switching element from the battery. A control unit suspends the switching operation of the switching element when the detected temperature rises to a temperature threshold. The control unit reduces counter electromotive force generated by the electric motor. The controller changes the temperature threshold such that the temperature threshold gradually increases from when the detected DC voltage is the highest voltage in the applicable voltage range of the battery to when the detected DC voltage is the lowest voltage in the applicable voltage range.

A motor-driven compressor includes an electric motor driven by a motor driver, which includes a switching element that converts DC voltage from a battery to AC voltage. A temperature detector detects the temperature of the switching element. A voltage detector detects DC voltage applied to the switching element from the battery. A control unit suspends the switching operation of the switching element when the detected temperature rises to a temperature threshold. The control unit reduces counter electromotive force generated by the electric motor. The controller changes the temperature threshold such that the temperature threshold gradually increases from when the detected DC voltage is the highest voltage in the applicable voltage range of the battery to when the detected DC voltage is the lowest voltage in the applicable voltage range.

The present invention relates to a pumping system to generate a vacuum (SP), comprising a main vacuum pump which is a claw pump (3) having a gas suction inlet (2) connected to a vacuum chamber (1) and a gas discharge outlet (4) leading into a gas evacuation conduit (5) in the direction of a gas exhaust outlet (8) outside the pumping system. The pumping system comprises a non-return valve (6) positioned between the gas discharge outlet (4) and the gas exhaust outlet (8), and an auxiliary vacuum pump (7) connected in parallel to the non-return valve. In a pumping method by means of this pumping system (SP), the main vacuum pump (3) is started up in order to pump the gases contained in the vacuum chamber (1) and to discharge these gases through its gas discharge outlet (4), simultaneously to which the auxiliary vacuum pump (7) is started up. Moreover the auxiliary vacuum pump (7) continues to pump all the while that the main vacuum pump (3) pumps the gases contained in the vacuum chamber (1) and/or all the while that the main vacuum pump (3) maintains a defined pressure in the vacuum chamber (1).

The present disclosure relates to an air conditioner and a compressor. The compressor includes: a first cylinder assembly, including a first cylinder body and a first sliding vane, a volume control assembly, including a pressure regulator; wherein the pressure regulator is provided with a storage cavity, and the storage cavity is communicated with the variable volume control cavity; wherein the first sliding vane is configured to slide in a reciprocating manner between the first compression cavity and the variable volume control cavity along the first sliding vane groove, to change the volume of the variable volume control cavity; and the refrigerant introduced into the variable volume control cavity flows between the variable volume control cavity and the storage cavity along with a change of the volume of the variable volume control cavity.

A high pressure compressor according to the present disclosure and a refrigerating cycle device to which the high pressure compressor is applied may include a casing having a sealed inner space; drive motor provided in the inner space of the casing; a compression unit provided in the inner space of the casing, and provided with a compression space for compressing refrigerant, and provided with a suction port for guiding refrigerant into the compression space, and provided with a discharge port for guiding refrigerant compressed in the compression space into the inner space of the casing a discharge valve provided in the compression unit to selectively open or close the discharge port according to a difference between a pressure of the inner space of the casing and a pressure of the compression space of the compression unit; a first valve configured to suppress refrigerant discharged from the inner space of the casing from flowing backward into the inner space of the casing; a bypass pipe connected between a discharge side and a suction side of the compression unit based on the compression unit; and a second valve provided at the bypass pipe to selectively open or close the bypass pipe.

A heat pump device includes a compressor including a compression mechanism that compresses a refrigerant and a motor that drives the compression mechanism, an inverter that applies a voltage for driving the motor, a converter that applies a voltage to the inverter, an inverter control unit that generates a driving signal for driving the inverter, and a converter control unit that generates a driving signal for driving the converter. The inverter control unit includes a heating-operation-mode control unit that controls a driving-signal generating unit such that the driving-signal generating unit outputs, as inverter driving signals, PWM signals for heating the compressor without rotationally driving the motor by feeding a high-frequency current that the motor cannot follow in a heating operation mode.

A heat pump device includes a compressor including a compression mechanism that compresses a refrigerant and a motor that drives the compression mechanism, an inverter that applies a voltage for driving the motor, a converter that applies a voltage to the inverter, an inverter control unit that generates a driving signal for driving the inverter, and a converter control unit that generates a driving signal for driving the converter. The inverter control unit includes a heating-operation-mode control unit that controls a driving-signal generating unit such that the driving-signal generating unit outputs, as inverter driving signals, PWM signals for heating the compressor without rotationally driving the motor by feeding a high-frequency current that the motor cannot follow in a heating operation mode.