Patent ID: 7611350

Claim:
An injection molding apparatus, comprising: a central control; a screw which extends in a cylinder, the cylinder comprising a filling opening and a nozzle, the screw being drivingly connected to first and second controllable electric motors by a driving connection such that a movement in rotational and/or axial direction can be imposed on the screw, the driving connection comprising a number of cylindrical planetary rollers accommodated for rotation in a planetary cage such that the planetary rollers can be engaged from a space located radially outside the planetary cage and a space located radially within the planetary cage, the planetary cage being connected to the screw in a manner secured against rotation and translation; a first drive part, connected to a rotor of the first electric motor, comprising a first engaging surface facing radially inward which engages the planetary rollers from the space located radially outside the planetary cage; and a second drive part, connected to a rotor of the second electric motor, comprising a second engaging surface facing outwards which engages the planetary rollers from a space located radially within the planetary cage.