PURPOSE: To lessen the load on a bearing part in such a way that even if the weight of balancers is diminished, balance effects just the same as in the former machinery can be obtained by providing balances respectively at the both end parts of a crankshaft of a rotary compressor.

CONSTITUTION: The first balancer 12 is solidly provided through a holder 11 on the lower end part of a crankshaft 8, and the second balancer 13 is provided on an end ring 5a on the upper side of a rotor 5 of a motor part. When the crankshaft 8 is turned, centrifugal force is respectively generated on its crank part 8a and a rotor 7, further on the first and second barancers 12, 13. In this case, even if the weight of the both balancers 12, 13 are small, it can be offset with the centrifugal force of the crank part 8a and the rotor 7, balances are held, and load on the both bearings can be greatly reduced.