An air compressor includes a tank unit that stores compressed air, a motor unit that generates compressed air to be stored in the tank unit, a pressure detection unit that detects a pressure value in the tank unit, and a control unit that drives the motor unit when a pressure value in the tank unit detected by the pressure detection unit is equal to or less than a motor start pressure value, and stops the motor unit when the pressure value in the tank unit detected by the pressure detection unit is equal to or greater than a motor stop pressure value. The control unit changes at least either of the motor start pressure value or the motor stop pressure value every time when a predetermined time passed.

An air compressor includes a tank unit that stores compressed air, a motor unit that generates compressed air to be stored in the tank unit, a pressure detection unit that detects a pressure value in the tank unit, and a control unit that drives the motor unit when a pressure value in the tank unit detected by the pressure detection unit is equal to or less than a motor start pressure value, and stops the motor unit when the pressure value in the tank unit detected by the pressure detection unit is equal to or greater than a motor stop pressure value. The control unit changes at least either of the motor start pressure value or the motor stop pressure value every time when a predetermined time passed.

A pressure-controlling device (10) includes a pump (21), a connection pipe (30), a first valve (41), and a second valve (42). The pump (21) has an inlet port (211) and an outlet port (212). The connection pipe (30) has a first end in communication with the outlet port (212), and a second end in communication with the inlet port (211) and that has a first space (31) that contains the first end, a second space (32) that contains the second end, and a third space (33) that is located between the first space (31) and the second space (32).

An object of the present invention is to provide a fluid compression system which can supply compressed fluid in accordance with a sudden change in an amount of fluid used even when the number of compressors to be installed is increased, and a control device thereof. In order to solve the problem, provided is a fluid compression system, including: a plurality of compression devices which compress fluid; and a number of device controller which controls the number of operating compression devices of the plurality of compression devices, in which at least one of the plurality of compression devices is configured of a plurality of compressor main bodies, and performs a volume control operation which changes the number of operating compression devices in accordance with an amount of compressed fluid used, or a fixed control operation which does not change an output during the operation regardless of the amount of the compressed fluid used, and the number of device controller switches a state where the plurality of compression devices perform the volume control operation and a state where the compression devices perform the fixed control operation.

A cordless compressor has an air storage tank, a pump, a motor for driving the pump, and a controller circuit electrically connected to the motor. A pressure switch assembly is connected to the controller circuit. The pressure switch assembly has first and second pressure switches for sensing pressure within the air storage tank. The controller circuit controls de-activation of the motor depending upon status of the first and second pressure switches.

A gas leak determining method for a multi-stage compressor including: a first compressing unit that compresses a gas; and a second compressing unit that further compresses the gas compressed by the first compressing unit includes: a step of calculating a proportion of discharge pressure from the second compressing unit to discharge pressure from the first compressing unit or suction pressure into the second compressing unit; and a step of determining that a gas is leaking from the second compressing unit when the proportion becomes equal to or less than a set value.

A compressed air production facility that reduces an extension cost without stopping an operating air compressor in a case of increasing the number of air compressors to cope with an increase in demands for compressed air is provided. A compressed air system supplies compressed air to compressed air consuming devices connected to a compressed air distributions line, the compressed air system including a plurality of air compressor units connected to the compressed air distributions line via respective air tanks. Each of the air compressor units includes: an air compressor main body; an adjustor of pressure setpoint that adjusts a pressure setpoint of an air tank to which the air compressor unit including the adjustor of pressure setpoint is connected; and a controller of air compressor that operates a rotational frequency of the air compressor main body on the basis of the pressure setpoint adjusted by the adjustor of pressure setpoint and a pressure of the air tank. The adjustor of pressure setpoint adjusts the pressure setpoint on the basis of a control variable indicating the rotational frequency of the air compressor main body or the pressure of the air tank.

In a method of an embodiment, a pressure sensor is selected from first and second pressure sensors according to a set flow rate. A measurable maximum pressure of the second pressure sensor is higher than a measurable maximum pressure of first pressure sensor. The target pressure of a chamber is determined according to the set flow rate. Until the pressure of the chamber reaches the target pressure after gas is started to be output from the flow rate controller to the chamber at an output flow rate according to the set flow rate and a pressure controller provided between the chamber and an exhaust apparatus is closed, the pressure of the chamber is measured by the selected pressure sensor. The output flow rate of the flow rate controller is determined from a rate of rise of the pressure of the chamber.

A support structure for supporting a human body. The support structure includes a plurality of zones, including a hip zone, a lumbar zone, and a shoulder zone. The support structure includes at least one air bladder cell being disposed in each of the plurality of zones, each of the at least one air bladder cell being a hermetically sealed body. An air pressure controller includes a plurality of air pumps being connected to a pliable manifold, the pliable manifold being connected to one or more of a plurality of solenoid valves. A plurality of inlet tubes can each be connected at a first end to one of the plurality of solenoid valves and at a second end to the inlet port of one of the at least one air bladder cell. The number of air bladder cells can be greater than the number of zones.

Systems and methods of the invention relate to diagnosing a compressor. A method may include monitoring a pressure of compressed air within a reservoir, actuating a piston within a cylinder of the compressor, and detecting a leak condition of an exhaust valve of the cylinder through recognition of a change in the monitored pressure of the compressed air within the reservoir during a time period in which the piston is actuated. A system is also disclosed including an engine, a compressor operatively connected to the engine, and a controller that is operable to determine a condition of the compressor.