Motor-driven compressor

A motor-driven compressor comprising:

• a compression mechanism, which includes a stationary scroll, a movable scroll, which orbits without being allowed to rotate, and a compression chamber located between the movable scroll and the stationary scroll, the volume of the compression chamber decreasing based on orbiting motion of the movable scroll;
• an electric motor accommodated in a motor chamber, wherein the electric motor includes a rotary shaft and drives the movable scroll via the rotary shaft;
• a main bearing, which is located in the vicinity of the compression mechanism and rotationally supports the rotary shaft;
• a suction pressure zone;
• a discharge pressure zone;
• and
• an oil passage, which is connected either to the compression chamber or the discharge pressure zone, wherein
• the rotary shaft has an in-shaft passage,
• the in-shaft passage has an inlet, which is directly connected to the oil passage, and an outlet, which opens to the motor chamber,
• the main bearing is exposed to the oil passage, and
• the motor chamber is the suction pressure zone.