A drive assembly for rotating and translating a shaft comprising a hollow shaft motor and a fluid cylinder. The hollow shaft motor rotates the shaft and the fluid cylinder moves the shaft lengthwise. The drive is particularly useful in the injection unit of an injection-molding machine. In one preferred embodiment the injection unit includes a hollow electric motor and a hydraulic cylinder. A first cylinder wall of the hydraulic cylinder is joined to a rotor of the hollow motor. A second cylinder wall of the cylinder is connected to a stationary portion of the hollow motor. A piston has two end portions. One end portion of the piston engages the first cylinder wall and the other end portion of the piston engages the second cylinder wall. Means for rotating the piston are attached to the rotor. The means for rotating also permits the piston end portions to slide along the cylinder walls. One channel means provides hydraulic fluid to drive the piston in a forward direction and another channel means provides hydraulic fluid to drive the piston in a reverse direction. Means are provided for attaching an injection screw to the piston. In the preferred arrangement, the cylinder is at least partially situated within the hollow motor.
Disclosed is a drive unit operable to translate and rotate a shaft, the drive unit including: (i) a hollow electric motor having a rotor, (ii) a fluid cylinder, (iii) means for connecting the shaft to the rotor of the hollow electric motor, (iv) means permitting the shaft to move lengthwise coupled with the fluid cylinder, and (iv) means connecting the fluid cylinder to the shaft, whereby the shaft may be rotated by the hollow electric motor and moved lengthwise by the fluid cylinder, and wherein the fluid cylinder has an outer wall coupled with the rotor of the hollow electric motor.
Fluid distributor and operational drive of a molding system, comprising: block forming manifold for distributing fluid, block including: first interface disposed on side of the block providing connection to stationary device; second interface disposed on block configured to provide connection to electric motor: cylinder bore formed in block, bore interconnected to fluid distribution circuit, cylinder bore open includes the first interface: shaft member being a translatable member, intermediate of ends of shaft member including piston section cooperative with cylinder bore, shaft member including interface member including coupler to engage with movable machine member, other end of the shaft member including operational member, interface disposed on section of the operational member: interface member end cap providing stop for piston section; and drive cap disposed on second interface, drive cap rotatable by electric motor, and rotation of drive cap rotates the shaft member through interface while permitting translational movement of shaft member.
