Patent ID: 6941767

Claim:
An oil equalizing circuit comprising: a plurality of oil separators that are configured to be provided on discharge sides of compression mechanisms that compress refrigerant in a vapor compression refrigeration system and configured to separate oil from refrigerant; a plurality of oil return pipes that are configured to connect each of the oil separators to an intake side of one of the compression mechanisms and configured to allow the oil separated by the oil separators to be delivered to the intake sides of the compression mechanisms; a communication pipe connected to the oil return pipes so that the oil return pipes can communicate with each other; a plurality of oil ON-OFF switching mechanisms that are provided in the oil return pipes and configured and arranged to ensure a flow of the oil from the oil separators to the communication pipe and to open and close such that the ON-OFF switching mechanisms turn on and shut off a delivery of the oil from the oil separators to the intake sides of the compression mechanisms; and a plurality of pressure reducing mechanisms that are provided in one of the oil return pipes and the communication pipe and configured to reduce pressure of the oil sent from the oil separators to the communication pipe and the intake sides of the compressor mechanisms.