A drive shaft system (100) comprising a shaft (80) connected to a motor via a coupling (50) and arranged to transmit a rotary movement from the motor to the rotor, at least two supports (65,75) arranged to position the shaft within a shaft housing (90), each support comprising at least one bearing (95,98), and at least one forcing element (135,145) arranged to force at least one of the supports against either an inner side of the shaft housing or an outer side of the shaft (80); such as to prevent turning and radial movements of the supports within the shaft housing while enabling axial movement of the shaft within the shaft housing. The bearings may be forced at either their inner or outer rings, and may be enclosed in a bearing housing (120) for protection and stiffness.