Rieter

Squirrel-cage induction motors with variable speed gears on the load side

Index

In this case the speed is changed not via the motor, but mechanically via adjustable tapered discs of the belt drive, similar to a cone gear. However, whereas the diameter ratios in a cone gear are changed by moving the belt on the pair of cones, the diameter is changed in this case by pushing together one part and pulling apart the second part of conical drive discs. The drive belt is thus moved to a larger diameter on the first pair of discs and a smaller diameter on the second pair. The change usually occurs in stages by means of a control device via pneumatic or hydraulic pistons and lever arrangements. The basic speed can be adjusted manually. Rieter has also developed an electronic control system with which several speed curves for the spindles can be programmed as required via the variable speed gear.

Fig. 42 – Variable-speed gear drive

Fig. 43 – Adjustments to the variable-speed gear drive