JPS55119994A - Rotary compressor - Google Patents

Abstract

PURPOSE:To prevent the rise of discharge temperature by passing part of gas again into a suction port when the difference between discharge pressure and suction pressure becomes greater than a set value. CONSTITUTION:The controller 20, attached to the bypass circuit 19 connecting the inside of the cylinder 9 wall to the suction port 16, is provided with the plunger 21 to open or close the bypass circuit 19 and moves reciprocally between the high- pressure chamber 22 into which discharge pressure is introduced and the low- pressure chamber 23 with suction pressure. In case where difference in pressure between the high-pressure chamber 22 and the low-pressure chamber 23 is smaller than the force of the spring 24, the plunger 21 moves toward the high-pressure chamber, the bypass circuit 19 is closed, and the compressor 1 makes normal operation. On the other hand, in case where the pressure difference is greater than the force of the spring 24, the plunger 21 moves to a place where the pressure difference balances with the force of the spring 24 toward the low-pressure chamber, and the bypass circuit 19 is opened. Thus, even if the compressor 1 is operated with high- speed rotation number, the abnormal rise of temperature of the discharged cooling medium can be prevented.