Abstract: The device for the compression of a gas comprises a motor (1), a piston (2) adapted to be displaced linearly in a pump body, transmission means (T) between the motor (1) and the piston (2) adapted to convert the rotary motion generated by the motor (1) into a reciprocating translatory motion by the piston (2). Speed varying means comprising a cam (12) are provided to impart a different speed to the piston (2) of the compressor according to the resistance opposing the motor (1) during one complete admission/compression cycle, so that the resisting torque is substantially constant and so that the motor (1) operates at its maximum torque and therefore at maximum efficiency. The section of the cam (12) is determined so as to ensure substantially isothermal compression of the gas.

Abstract: Device for the compression and storage of air comprising, on the one hand, a reservoir (1) provided with an air discharge head (5) intended for cooperation with a container to be charged with compressed air and, on the other hand, at least one compression chamber (C1), associated with air inlet valves (19) and air ejection valves (15) and with a compression element actuated by a motor means (13) compressing the volume of the chamber (C1) between a maximum volume and a minimum volume, the ratio between the maximum volume and the minimum volume of the said chamber (C1) being from 1.2 to 20.