A compressor is mounted on a product. The compressor includes a drive shaft having an eccentric shaft portion, an electric motor with a rotor, a compression mechanism, a balancer forming a rotary system with the drive shaft and the rotor, a casing, a suction pipe, and a discharge pipe. The compression mechanism has a piston and cylinder to form a fluid chamber, and a blade dividing the fluid chamber into low and high pressure chambers. At a connection portion of the compressor with the product, a composite vibration is a first vibration or less, the composite vibration is a synthesis of the first vibration due to torque according to a pressure difference between the low and high pressure chambers, a second vibration due to an inertial force acting on the piston by the eccentric rotational movement, and a third vibration due to a centrifugal force acting on the rotary system.

A compressor is mounted on a product. The compressor includes a drive shaft having an eccentric shaft portion, an electric motor with a rotor, a compression mechanism, a balancer forming a rotary system with the drive shaft and the rotor, a casing, a suction pipe, and a discharge pipe. The compression mechanism has a piston and cylinder to form a fluid chamber, and a blade dividing the fluid chamber into low and high pressure chambers. At a connection portion of the compressor with the product, a composite vibration is a first vibration or less, the composite vibration is a synthesis of the first vibration due to torque according to a pressure difference between the low and high pressure chambers, a second vibration due to an inertial force acting on the piston by the eccentric rotational movement, and a third vibration due to a centrifugal force acting on the rotary system.

A rotor is shown with an asymmetrical structure for a pump, wherein the rotor includes at least one cutting edge and at least one rounded edge, as well as the pump as such including one or more rotor(s). The rotor (1) has a first circular element (4) where a material-moving cavity (5) is provided in the first circular element (4).