| 摘要 |
PURPOSE:To dispense with gears, a gap sensor, and the like used for the detection of the revolution number of a motor and enable very accurate detection of the revolution number at a low cost by a method wherein not only the motor rotor of an induction motor is made zero in skew but also a search coil is provided to a motor stator. CONSTITUTION:A closed type motor-driven compressor provided with a revolution number detecting mechanism whose compression component 8 is driven by the torque of an induction motor 4 housed in a sealed case 1 is provided, where a motor rotor 3 of the induction motor 4 is made zero in skew. Moreover, a search coil 19 which detects a slotted high frequency ripple induced in a motor stator 2 of the induction motor 4 is provided, and the revolution number of the induction motor 4 is detected by the slotted high frequency ripple detected by the research coil 9. By these processes, gears, a gap sensor, and a connecting member which connects the gears with a crank shaft 5 can be dispensed with, and not only a space that houses these components can be eliminated but also a very accurate revolution number of a motor can be detected. |
