Abstract: In a centrifuge in which a truncated-cone-shaped angle rotor is disposed in an outer casing and driven by a motor disposed in the outer casing and a plurality of sample tube containers are mounted in the angle rotor to extend radially along its peripheral surface, an air guide is provided for guiding air from the outside of the outer casing to the peripheral surface of the angle rotor, by which the air thus guided flows down the peripheral surface of the angle rotor to cool it.

Abstract: In a centrifuge, a rotor is housed in an inner housing and driven by a motor disposed outside thereof. By the rotation of the rotor, gas is blown off to be exhausted from the inner housing through exhaust ports formed therein, and at the same time, gas is drawn into the inner housing through an intake formed in a lid of the inner housing to cool the rotor. A guide is provided around the inner housing, by which the gas exhausted from the exhaust ports is led to one end portion of the motor to flow into the motor through holes made in a motor frame to cool the motor. The gas passing into the motor is discharged from the other end of the motor and then expelled to the outside of an outer casing of the centrifuge.