Compressor

A compressor comprising:

• a closed container;
• a compression element placed within the closed container;
• and
• a motor placed within the closed container to drive the compression element via a shaft,
• the compression element and the motor being arranged and configured such that an integral structure part is formed by integrally assembling the compression element and a rotor of the motor via the shaft,
• a coil of a stator of the motor being provided in concentrated winding,
• a cylindrical-shaped rotor core of the rotor having a small-diameter portion and a large-diameter portion provided inside the cylindrical-shaped rotor core,
• the shaft being fixed to the small-diameter portion of the cylindrical-shaped rotor core,
• a bearing of the compression element being arranged to support the shaft and being inserted into the large-diameter portion of the cylindrical-shaped rotor core, with the shaft being cantilevered by the bearing, and
• the integral structure part having a natural frequency larger than five times a maximum number of rotations of the compressor during operation.