Rolling ring drive

Rolling ring gears (also called Uhing gears , named after the Kiel engineer Joachim Uhing , who applied for a patent in 1954 ) convert the constant rotary motion of a smooth shaft into a reciprocating stroke motion .

They act like nuts on screw spindles , but have a variable pitch that can be left or right and can also be zero. This effect is achieved by three or four pivotably arranged rolling rings that enclose the shaft and with their specially shaped running surfaces are alternately pressed against its surface. If the rolling ring drive runs against a pre-positioned end stop, a mechanical switching mechanism is actuated, which swivels the rolling rings in the opposite direction and initiates the stroke reversal.

Rolling ring drives are available for shaft diameters from 10 to 80 mm. Depending on their size, they achieve thrust forces of up to 3,600  N , lifting speeds of up to 4 m / s and stroke lengths of up to 5 m.

The main area of ​​application of the rolling ring drive is the distribution of strip-shaped material on reels . Between the end stops, which are set to the flange distance, the rolling ring drive runs back and forth with a pitch that is set to the diameter of the material being wound, thus ensuring that the winding is built properly .

A simplified version of the rolling ring drive is the drive nut, also developed by Uhing, in which the rolling rings are installed at a fixed angle. Changes in lifting speed and direction are made via the shaft drive. Because of their principle-related game freedom the roll nut is preferred as the final drive in measuring machines used.