An air compressor having a pressure gauge, the pressure gauge contains: a hollow tube, a drive element, an anti-leak spring, a resilient element, and a cap. The hollow tube includes an accommodation chamber, a connector having a conduit, and a display unit. The drive element includes a protection unit, a first open segment, a second distal segment, a receiving portion, a hollow extension, and a protrusion. An anti-leak spring is received in the hollow extension of the drive element, a first end of the anti-leak spring abuts against the protrusion, and a second end of the anti-leak spring contacts with the protection unit. The resilient element is received in the receiving portion of the drive element. The cap includes a seat, a push bolt, and multiple passages. An end of the resilient element contacts with the cap.

A display structure of a pressure gauge of an air compressor, the air compressor is received in an accommodation box, and a scale portion of the pressure gauge is viewable via a displaying opening of the accommodation box, the pressure gauge includes a cylindrical body which is transparent and is formed in a pen shape, and the pressure gauge includes a colored O-ring configured to indicate a pressure value of the scale portion. The scale portion is not printed on the cylindrical body of the pressure gauge and includes a transparent panel on which the pressure value of the scale portion is marked on an internal face of the transparent panel, and the internal face faces the cylindrical body of the pressure gauge.

The present invention relates to a hydraulic pump system including a variable displacement pump that generates an outlet pressure. The hydraulic pump system also includes a control system that decreases a displacement volume of the variable displacement pump in response to an increase in the outlet pressure and increases a displacement volume of the variable displacement pump in response to a decrease in the outlet pressure.

A rig management system is disclosed. The rig management system may be configured to receive information to be used to control shifting of a transmission to prevent cavitation during use of the hydraulic fracturing rig. The rig management system may be configured to determine a flow rate for a pump based on the information. The rig management system may be configured to determine an output torque of the transmission based on the flow rate. The rig management system may be configured to determine a transmission gear for the transmission based on the output torque and a fuel consumption map, wherein the fuel consumption map identifies a respective fuel consumption rate for different combinations of transmission gears and output torques. The rig management system may be configured to cause the transmission to shift into the transmission gear after determining the transmission gear.

In order to improve a refrigerant compressor, including a compressor unit having a compressor housing and at least one compressor element that is arranged in the compressor housing, for compressing refrigerant, and further including a drive unit having a drive housing and an electric motor that is arranged in the drive housing and connector terminals that are arranged on the drive housing, for the electric motor, and further including an electronic functional unit, such that the connection between the refrigerant compressor and the electronic functional unit is achievable as simply as possible, it is proposed that the connector terminals should be provided in a housing that is arranged on the drive housing, and that an electronic functional unit which performs at least one compressor function should be provided in the housing.

The present disclosure provides a method and system for delivering a high-viscosity fluid 300. In an example, a reciprocating a piston pumps a high-viscosity fluid 300 through a one-way check valve 130 into a pump chamber 125. Responsive to receipt of a request for a dose of the high-viscosity fluid 300, an output valve 135 in the pump chamber 125 is opened, and the piston is reciprocated in order to eject a dose of the high-viscosity fluid 300 from the pump chamber 125 through the output valve 135.

In a pressurized cleaning apparatus comprising a pressure generation unit for pressurizing a fluid, in particular for supplying a pressurized fluid via a hose attachment, preferably via a hand-held pistol or a spray nozzle, an operating unit is provided that is designed to make it possible to set a maximum operating pressure of the pressure generation unit at which the pressure generation unit is deactivated.

An inflator includes an inflator housing, a pressure sensor operable to generate a pressure signal related to an outlet pressure of the inflator, a motor within the inflator housing, a battery pack removably coupleable to the inflator housing, and a controller electrically coupled to the motor and the battery pack. The controller is configured to receive the pressure signal from the pressure sensor, determine a rate of pressurization change based on the pressure signal, determine a static pressure value based on the rate of pressurization change, and determine a motor time delay based on a target pressure value, the static pressure value, and the rate of pressurization change. The controller is also configured to generate a control signal when the motor time delay substantially equals zero. The control signal is operable to cause power to the motor to be turned off to stop a pressurization condition of the inflator.

A pump for high-pressure and/or nano-scale volumes permits identification of the internal pressure of the pump.

In order to improve a refrigerant compressor, including a compressor unit having a compressor housing and at least one compressor element that is arranged in the compressor housing, for compressing refrigerant, and further including a drive unit having a drive housing and an electric motor that is arranged in the drive housing and connector terminals that are arranged on the drive housing, for the electric motor, and further including an electronic functional unit, such that the connection between the refrigerant compressor and the electronic functional unit is achievable as simply as possible, it is proposed that the connector terminals should be provided in a housing that is arranged on the drive housing, and that an electronic functional unit which performs at least one compressor function should be provided in the housing.