Compressor device that comprises a compressor element that is equipped with a compression chamber with at least one coolant inlet, and which furthermore comprises a gas outlet, a gas/coolant separation tank connected to it, and, a cooling circuit with a cooler that extends between the separation tank and the coolant inlet, and which is equipped with control means to adjust the temperature of the coolant flow supplied to the compressor element, whereby the aforementioned control means comprise a first and a second sub-controller, each with a different target parameter, whereby the control means also comprise switching means to place one of the two sub-controllers in an activated state and the other sub-controller in a deactivated state.

A downhole dynamometer for a rod pumping unit is provided. The downhole dynamometer includes a shell within which a plurality of sensors, a non-transitory memory, and a dynamometer controller are located. The shell is configured to be coupled to a sucker rod string of the rod pumping unit and disposed in a well opposite a wellhead of the well. The plurality of sensors is configured to measure downhole accelerations of the sucker rod string and to measure a downhole load on the sucker rod string. The dynamometer controller is coupled to the plurality of sensors and the non-transitory memory. The dynamometer controller is configured to periodically collect measurements from the plurality of sensors and store the measurements in the non-transitory memory.

Systems and methods are provided and include a compressor for a refrigeration system and a duct assembly that includes a duct frame and a sensor unit. The duct frame provides a path for evaporating refrigerant from a lubricant sump of the compressor. The sensor unit obtains temperature measurements of the refrigerant and a lubricant within the lubricant sump and heats and evaporates the refrigerant located within the duct frame of the duct assembly. A control module receives temperature measurements from the sensor unit, determines a presence of liquid refrigerant within the lubricant sump of the compressor in response to a determination that an actual temperature change does not correspond with an expected temperature change for the lubricant, and in response to a determination that the actual temperature change corresponds with the expected temperature change for the lubricant, operates the compressor.

The present disclosure relates to a piston pump assembly comprising a piston with a variable stroke and to a hydraulic braking system comprising the same. The piston pump assembly comprises at least: a rotatable drive shaft defining an axis of rotation of the rotatable drive shaft; a cam disposed on the drive shaft; and the piston biased toward the cam and configured to reciprocate along a piston axis for displacing a hydraulic fluid. The cam is movable relative to the piston axis and is selectively placed in one of a first position at a first distance from the piston axis and a second position at a second distance from the piston axis; and wherein the cam comprises at least two portions each of which has, at a given position of the cam relative to the piston axis, a different non-circular cross section in a plane perpendicular to the axis of rotation and/or a different eccentricity with respect to the axis of rotation, the at least two portions of the cam comprising at least a first cam portion having a first non-circular cross section and/or a first eccentricity, and a second cam portion having a second non-circular cross section and/or a second eccentricity.

A process to pump liquid held in a passive tank to an active tank when the active tank has a liquid level below a set point level and when the passive tank contains liquid at a temperature above the freezing point of the liquid, the active tank including a discontinuous level gauge configured to provide at least x+1 indications of the level of liquid in tank as a function of the relative position of a moving part with respect to x set point levels, x being at least equal to 2. The process includes: reading the level indication from a level gauge; starting a pump and measuring a time during which a pump transfers liquid; stopping the pump if this time is greater than a time constant, which depends on the value of the level indication, and if a next set point level is not reached.

The present disclosure provides a variable-capacity compressor, a variable-capacity two-stage compression system and a control method thereof. The compression system includes a compressor, wherein the compressor includes a low pressure cylinder and a high pressure cylinder connected in series, wherein the low pressure cylinder comprises at least two cylinders connected in parallel. The compression system further comprises a control mechanism that can control at least one of the at least two cylinders connected in parallel to perform full-load and/or no-load operation.

A method and a device for controlling the delivery rate of a concrete pump for filling a formwork arrangement with a pumpable filling compound as a function of curing-relevant material and environmental parameters, after which the installed filling compound sets within the formwork arrangement, comprising the following steps: determining a permissible climbing speed for filling the formwork arrangement with the filling compound on the basis of the material and ambient parameters, measuring the static filling compound pressure acting on the formwork arrangement during filling, and calculating the permissible delivery rate of the concrete pump as a function of the determined permissible rate of ascent and the measured static filling compound pressure at the formwork arrangement.

The utility model discloses a smart control water pump applicable to ponds and swimming pools for water drainage includes a chassis, an outer housing, an inner housing, a motor front end cap, a motor housing body, a motor rear end cap and an motor insulating cover, wherein the outer housing, the inner housing and the motor housing body are disposed in turn from the outside to the inside; a flow channel is formed between the outer housing and the inner housing; the chassis, together with the motor front end cap and the bottom of the inner housing, forms an impeller cavity; an impeller is disposed in the impeller cavity; the motor rear end cap, together with the motor housing body and the motor front end cap, forms a motor cavity; a motor component which is in transmission with the impeller is disposed in the motor cavity; and the smart control water pump also includes a smart control component, and includes a controlled in the motor insulating cover, and a temperature sensor and a liquid level sensor which communicate with the controller and are disposed at the flow channel. Compared with the prior art, the utility model has the advantages of preventing overturning and toppling and avoiding frozen burning.

A simple inverter-controlled refrigerator includes temperature detector (17), constant speed main body control unit (12) whose power is turned on/off by temperature detector (17), and that can drive a constant speed compressor, inverter control unit (14) that is connected to constant speed main body control unit (12), and that is operated, based on a power on/off signal of constant speed main body control unit (12). And variable speed compressor (8) that is connected to inverter control unit (14), and that is controlled, based on an output from inverter control unit (14). Inverter control unit (14) has rotation speed setting unit (23) which is operated, based on the power on/off signal of constant speed main body control unit (12), and which is configured to set a rotation speed of variable speed compressor (8), and inverter drive circuit unit (24) which drives variable speed compressor (8) at the rotation speed set by rotation speed setting unit (23).

An electric device having a casing with an air-outlet, and a main unit disposed inside the casing, includes a first temperature sensor configured to detect the temperature inside the casing, a second temperature sensor installed in the vicinity of the air-outlet, and an electric fan configured to generate an airflow from the air-outlet toward the inside of the casing at the time of the low-temperature startup such that the temperature detected by the first temperature sensor is lower than a preset first threshold value, and the temperature detected by the second temperature sensor is higher than the temperature detected by the first temperature sensor.