An air pump system includes a housing defining a first vent in fluid communication with an interior cavity of an inflatable member, a first one-way valve configured to open or close the first vent, a main pump having a main pump inlet and a main pump outlet, a valve control assembly for selectively opening or closing the one-way valve, an air pressure control assembly for sensing an air pressure of the interior cavity and generating a first air pressure signal when the air pressure reaches a first threshold air pressure, and generating a second air pressure signal when the air pressure reaches a second threshold air pressure, and a control device in electrical communication with the main pump, valve control assembly and the air pressure control assembly.

An arrangement of screws for a screw compressor for a utility vehicle includes at least one female screw and at least one male screw. The female screw and the male screw each have teeth that engage with one another. The teeth of the female screw have a roll-off tooth flank which is provided for rolling-off a tooth flank of the male screw. The roll-off tooth flank has a convexly rounded roll-off tip region in the tip region, which has a first radius, wherein a tooth base is provided between two neighboring teeth of the female screw, which is connected to the roll-off tip region via a flat transition region. The tooth base between two teeth of the female screw is substantially concavely rounded and has a second radius, wherein the second radius is approx. 2.5 to 3.5 times greater than the first radius.

An air compressor (10) includes an air pump (34) with a pump inlet (34a) for receiving air to be pressurized and a pump outlet (34b). An air tank (14) includes a tank inlet (14a) coupled with the pump outlet (34b) for receiving pressurized air from the air pump (34), and a tank outlet (14b) for directing pressurized air from a tank outlet (14b) to at least one pneumatic device (24). A brushless DC motor (36) includes a rotatable output (36a) coupled with the air pump (34) for operating the air pump (34) to pressurize air. A control (42) is electrically coupled to the brushless DC motor (36). The control (42) changes the level of electric current drawn by the brushless DC motor (36) to thereby change the rate of rotation of the rotatable output (36a) and/or the pump performance level.

A screw compressor for a utility vehicle includes a housing. The housing is filled with oil. At least one pair of compressor screws are mounted in the housing and serve to compress air supplied to the screw compressor. In the assembled state, a heat exchanger is directly placed onto and installed on the housing, by which heat exchanger the temperature of the oil contained in the housing can be controlled.

An electrically operated device (10) includes an electric motor (36) with an electrical cord set (30). The cord set (30) includes an electrical connecting plug (80) for coupling with an AC electrical outlet. The device (10) further includes a detector (46). A control (42) is electrically coupled to the motor (36) and electrically coupled to the detector (46) for controlling the level of electric current drawn by the electric motor (36) from the AC electrical outlet. The detector (46) detects whether the electrical connecting plug (80) is connected to a 15 Amp electric receptacle or to a 20 Amp electric receptacle and, in response, the control (42) establishes the electric profile of the electric motor (36) to correspond to the 15 Amp electric receptacle or to the 20 Amp electric receptacle.

To provide an air compressor capable of achieving energy saving. The air compressor is provided with a compressor body compressing air with injecting oil into a compression chamber; an air-pressure-operated intake throttle valve provided on an intake side of the compressor body; a separator provided on a delivery side of the compressor body and separating, from the compressed air delivered from the compressor body, a liquid contained in the compressed air; a compressed air system supplying the compressed air separated by the separator to a supply destination; an air release system connected to a primary side of a check valve in the compressed air system; an air-pressure-operated air release valve provided in the air release system; and an air-pressure operation circuit having a solenoid-operated three-way valve.

A gas ejection apparatus includes: a cylinder having a rotating member that rotates within the cylinder; a motor coupled to the rotating member of the cylinder and that causes gas to be compressed inside the cylinder and to he ejected from the cylinder by causing rotation of the rotating member; a control circuit board that controls the motor; and a case in which the cylinder, the motor and the control circuit board are disposed. The case extends in a planar direction and has side surfaces that are orthogonal to the planar direction. The motor and the cylinder are arranged adjacent to each other in the planar direction of the case. The control circuit board is disposed adjacent to and substantially parallel to one of the side surfaces of the case.

Power systems and methods of controlling an engine driven air compressor include an air compressor driven by an engine via a clutch. A first pressure sensor configured to sense a pressure level at an outlet of the air compressor. An inlet valve configured to close in response to the first pressure sensor sensing a pressure level above a first pressure level. In addition, a second pressure sensor to sense a pressure level below a second pressure level at a housing of the air compressor, wherein the clutch is configured to disengage in response to the second pressure level, wherein the first pressure level is higher than the second pressure level.

A water lubrication air compression system disposes an lubricant heat dissipation system at a bearing chamber close to the high pressure end of the compressor for cooling and circulating lubricant due to the rise of temperature during operation of the compressor, hence enhancing the ability and stability of the compressor. On the other hand, a negative pressure system is connected to the air chambers between the oil lubrication and the water lubrication of the compressor in order to provide a negative pressure. If any leak of water vapor at the compressor chamber or oil vapor at the bearing chamber, the negative pressure system is able to produce a negative pressured condition toward the sealing structure so that the oil lubrication can be effectively isolated from the water lubrication and inter-contamination between the lubricant and water can be avoided.

A screw compressor 2 includes a compressor main body 4, a motor 8, and a gearbox 10. The compressor main body 4 includes screw rotors 5c, 5d, 6c, and 6d, rotor casings 5e and 6e accommodating therein the screw rotors 5c, 5d, 6c, and 6d, and main body casings 5a and 6a accommodating therein the rotor casings 5e and 6e, the main body casings being provided with first flanges 5b and 6b on respective ends thereof. The motor 8 drives the screw rotors 5c, 5d, 6c, and 6d via gears 10f and 10g. The gearbox 10 has an attachment surface Son which the first flange 6b to the main body casings 5a and 6a is attached, accommodates therein the gears 10f and 10g, and has a substantially rectangular shape. In a state where the compressor main body 4 is attached to the gearbox 10, a part of the first flange 6b extends to an outside of the attachment surface S, and projection regions of the rotor casings 5e and 6e onto the attachment surface S exist within the attachment surface S. In this way, vibrations of the screw compressor 2 can be reduced.