Motor-driven compressor

Abstract

A motor-driven compressor includes an electric motor, a compression mechanism, which compresses gas by being driven by the electric motor, and a body accommodating the electric motor and the compression mechanism. The motor-driven compressor includes a motor control section, which drives the electric motor by controlling power supply to the electric motor, a vibration control section, which generates a waveform in a phase opposite to the waveform of vibration predicted to be generated in the body due to the driving of the electric motor, and a vibration applying device, which is located on the body and applies vibration in the opposite phase generated by the vibration control section to the body.

1 . A motor-driven compressor comprising:
 an electric motor;   a compression mechanism, which is driven by the electric motor to compress gas;   a body, which accommodates the electric motor and the compression mechanism;   a motor control section, which drives the electric motor by controlling a power supply to the electric motor;   a waveform generation section, which generates a waveform in a phase opposite to the waveform of vibration predicted to be generated in the body due to driving of the electric motor; and   at least one vibration applying device, which is located on the body and applies to the body vibration having the waveform in the opposite phase generated by the waveform generation section.   
     
     
         2 . The motor-driven compressor according to  claim 1 , further comprising:
 a vibration detection section, which detects vibration generated in the body due to driving of the electric motor; and   a waveform correction section, which, on the basis of a detection result of the vibration detection section, corrects the waveform in the opposite phase generated by the waveform generation section such that the vibration detected by the vibration detection section decreases.   
     
     
         3 . The motor-driven compressor according to  claim 1 , wherein
 the body includes a mounting portion, which fixes the body to a base, and   the at least one vibration applying device is located on the mounting portion.   
     
     
         4 . The motor-driven compressor according to  claim 1 , wherein
 the body has an outer surface and a discharge chamber into which compressed gas is discharged from the compression mechanism therein; and   the at least one vibration applying device is located on the outer surface of the body at a portion where the discharge chamber is formed.   
     
     
         5 . The motor-driven compressor according to  claim 4 , further comprising:
 a discharge valve, which is provided in the discharge chamber and prevents the compressed gas discharged from the compression mechanism from flowing back to the compression mechanism,
 wherein the at least one vibration applying device is located to face the discharge valve. 
   
     
     
         6 . The motor-driven compressor according to  claim 1 , wherein
 the electric motor includes an output shaft,   the body has an outer surface,   the compression mechanism includes a movable member, which is fixed to the output shaft of the electric motor and orbits around an axis of the output shaft along with driving of the electric motor, and   the at least one vibration applying device is oriented in a direction orthogonal to the output shaft of the electric motor and located on the outer surface of the body at a portion where the compression mechanism is located.   
     
     
         7 . The motor-driven compressor according to  claim 6  wherein
 the electric motor includes a rotor fixed to the output shaft, and the waveform generation section predicts a phase of vibration generated in the body from an angular position of the rotor. 
 
     
     
         8 . The motor-driven compressor according to  claim 1 , wherein
 the body includes a mounting portion, which fixes the body to a base, and the body has an outer surface, and   the at least one vibration applying device is located on the outer surface of the body and at a position most separated from a contact portion of the base in the mounting portion.   
     
     
         9 . The motor-driven compressor according to  claim 1 , wherein
 the waveform generation section predicts a waveform of vibration generated in the body on the basis of a rotation speed of the electric motor.   
     
     
         10 . The motor-driven compressor according to  claim 1 , wherein
 the at least one vibration applying device includes a piezoelectric device, which applies vibration to the body through expansion/contraction according to an applied voltage.