| 摘要 |
<p>Appts for rotating and axially displacing either alternately or simultaneously, a machine part, esp. a plasticising screw spindle within a hollow cylinder of an injection moulding machine, has a plug connecting a piston to the spindle, the piston having a lengthwise opening, that is outwardly sealed at its end directed towards the spindle by the plug, and receives a driving shaft connected to the motor at its other end. the shaft has a seal section, contacting the inner surface of the piston at one end, and a second seal section near its end connected to the motor the second seal section having a sleeve capable of sliding in a sealed manner against the hollow cylinder. Between the two seal sections the piston and the driving shaft are coupled together so that they can be displaced together, but not rotated, and the shaft has a passage effecting a first hydraulic connection with the end section of the opening neat the spindle. A second hydraulic connection discharges in the cylinder between the second seal section and the end of the sliding face of the piston directed towards the seal section. The appts requires no axial bearing for receiving the force developed on the spindle during plasticisation. The machine is therefore both cheaper and lighter, as such bearings are generally large and strong.</p> |
