The invention relates to a refrigeration compressor that comprises an integral housing, an electric motor housed in said integral housing and comprising a stator and a rotor sitting on a drive shaft, a screw compressor, disposed in said integral housing, whose compressor screw sits on the drive shaft that is rotatably mounted in the integral housing by a first radial bearing between the rotor and the compressor screw, and a second radial bearing disposed on the side of the compressor screw opposite the first radial bearing. The aim of the invention is to improve said compressor in such a way as to eliminate the risk of the rotor touching the stator. To this end, the drive shaft is mounted in the integral housing on a third radial bearing which is disposed on the side of the rotor opposite the first radial bearing. A drive section of the drive shaft that extends between the first radial bearing and the third radial bearing is further adapted to compensate for any alignment errors between the three radial bearings.