| 20110162746 | OIL BALANCE DEVICE, A COMPRESSOR UNIT AND A METHOD FOR PERFORMING AN OIL BALANCE OPERATION BETWEEN A PLURALITY OF COMPRESSOR UNITS - The present invention disclosures an oil balance device and a method for performing an oil balance operation between a plurality of compressor units, which are suitable for air conditioner units comprising at least two parallel connected compressor units. Each compressor unit comprises at least one parallel connected compressors. The oil balance device comprises an oil reservoir, a first pipe, a second pipe, a third pipe and a fourth pipe. The four pipes communicate with the oil reservoir respectively. Each pipe is provided with at least one valve to control the opening and the closing of the corresponding pipe. The first valve and the fourth valve are closed and the second valve and the third valve are opened if the compressor unit is in normal operation; the first valve and the fourth valve are opened and the second valve and the third valve are closed if the compressor unit supplies oil; the second valve and the fourth valve are opened and the first valve and the third valve are closed, or the third valve and the fourth valve are opened and the first valve and the second valve are closed, if the compressor unit receives oil. | 07-07-2011 |