A reciprocating piston air compressor includes a programmable logic controller, a tank, a motor, a pump, a variable speed drive, a head unloader and a cooling system. The programmable logic controller and/or variable speed drive are utilized to monitor the operating state of the air compressor and to control various operational variables, such as motor and pump speed. The air compressor can utilize the variable speed drive to operate a three phase motor on single-phase power.

A method for controlling a well pumping system is provided. The method includes the steps of entering a pump intake depth, a minimum fill preset, a maximum fill preset, and a gain value into a controller for the well pumping system, and determining a fluid over pump level. If the fluid over pump level is zero, the method calls for setting a target pump fill equal to the maximum fill preset. If the fluid over pump level is not zero, the method calls for calculating a fluid over pump ratio using the pump intake depth, and calculating the target pump fill using the fluid over pump ratio and the gain value. Further, the method includes calculating a pump fill error as the difference between the target pump fill and an actual pump fill. The method further includes controlling a pumping speed of the well pumping system based on the pump fill error.

A method for controlling a well pumping system is provided. The method includes the steps of entering a pump intake depth, a minimum fill preset, a maximum fill preset, and a gain value into a controller for the well pumping system, and determining a fluid over pump level. If the fluid over pump level is zero, the method calls for setting a target pump fill equal to the maximum fill preset. If the fluid over pump level is not zero, the method calls for calculating a fluid over pump ratio using the pump intake depth, and calculating the target pump fill using the fluid over pump ratio and the gain value. Further, the method includes calculating a pump fill error as the difference between the target pump fill and an actual pump fill. The method further includes controlling a pumping speed of the well pumping system based on the pump fill error.

To prevent generation of drain reliably without depending on a difference in ambient temperature where a compressor is installed. Provided is a gas compressor: having a compressor main body compressing a gas, a drive source driving the compressor main body, a controller controlling the rotation speed of the drive source according to the discharge pressure of the compressor main body, and a temperature detector detecting the temperature of a discharge gas of the compressor main body; and performing no-load operation with the rotation speed of the drive source as a lower limit rotation speed when the discharge pressure reaches an upper limit pressure higher than a set pressure. When detecting that the temperature detected by the temperature detector is equal to or lower than a predetermined temperature during the no-load operation, the controller causes the lower limit rotation speed of the drive source to a lower limit rotation speed at which the temperature of the discharge gas is higher than the predetermined temperature and which is higher than a lower limit rotation speed when the detected temperature is higher than the predetermined temperature.

To prevent generation of drain reliably without depending on a difference in ambient temperature where a compressor is installed. Provided is a gas compressor: having a compressor main body compressing a gas, a drive source driving the compressor main body, a controller controlling the rotation speed of the drive source according to the discharge pressure of the compressor main body, and a temperature detector detecting the temperature of a discharge gas of the compressor main body; and performing no-load operation with the rotation speed of the drive source as a lower limit rotation speed when the discharge pressure reaches an upper limit pressure higher than a set pressure. When detecting that the temperature detected by the temperature detector is equal to or lower than a predetermined temperature during the no-load operation, the controller causes the lower limit rotation speed of the drive source to a lower limit rotation speed at which the temperature of the discharge gas is higher than the predetermined temperature and which is higher than a lower limit rotation speed when the detected temperature is higher than the predetermined temperature.

A fluid pump comprises an electric motor configured to provide a unidirectional rotational output. The fluid pump further comprises a screw drive coupled to the electric motor. The screw drive is configured to convert the unidirectional rotational output of the electric motor into reciprocating motion to linearly reciprocate a piston coupled to the screw drive.

A fluid pump comprises an electric motor configured to provide a unidirectional rotational output. The fluid pump further comprises a screw drive coupled to the electric motor. The screw drive is configured to convert the unidirectional rotational output of the electric motor into reciprocating motion to linearly reciprocate a piston coupled to the screw drive.

A pump is provided that includes a tube 1, tube rotors 21A, 21B, and 21C in contact with the tube 1, a case 3 containing the tube 1 and tube rotors 21A, 21B, and 21C, and a drive apparatus 10 that rotates the tube rotors 21A, 21B, and 21C from outside the case 3 without contacting the tube rotors 21A, 21B, and 21C.

An oxygen concentrator may have a compressor to feed a feed gas for sieve bed(s) via a first manifold, an accumulator to receive enriched air from the bed(s) via a second manifold. It may include an outer housing for the manifolds, the compressor, and the accumulator. The housing may include an access portal to a compartment therein, for removably receiving the bed(s) as a canister assembly. The first manifold may be adjacent to the compartment and have inlet coupling(s) for removably coupling respectively with inlet(s) of the canister assembly. The inlet coupling(s) may each have a first central axis. The second manifold may be adjacent to the compartment and have outlet coupling(s) for removably coupling respectively with outlet(s) of the canister assembly. The outlet coupling(s) may each having a second central axis. The first and second central axes may form any one of an obtuse, acute, or right angle.

This application provides a powertrain, a coolant flow rate estimation method, and an electric vehicle. Coolant in a first cooling loop of the powertrain is configured to cool an inverter. An electronic pump drives the coolant to circulate in the first cooling loop. When a phase current of a motor is greater than or equal to a preset current value, a controller determines a rotation speed of the electronic pump at a first moment as a first rotation speed, and determines a coolant flow rate at the first moment based on a temperature at a first position in the first cooling loop, a temperature at a second position in the inverter, and a power loss of the inverter. In the solution of this application, data does not need to be separately calibrated for different thermal management systems. This reduces time consumed by data calibration and improves practicability.