When designing an intermittent motion mechanism using a partially toothed gear, it is necessary to install a locking mechanism (such as nails or hooks) so that the driven shaft side will remain stopped after rotating intermittently by the forces transmitted from the driving shaft. In this volume, we will look into an easier and more convenient method using a friction wheel, eliminating the brake system from the mechanism.

(1) Intermittent motion mechanism using friction force

As shown in [Fig.1], a notch on the driving shaft side (1) is designed to generate intermittent motion. On the driven shaft side (2), a driven pulley with a rubber ring installed is secured around the outer periphery of the circular disk for increased friction resistance. When they come into contact under certain contact pressure, it will generate intermittent motion in accordance with the shape of the notch designed on the driving shaft. Although this mechanism does not require a brake system on the driven shaft side, it is not designed for movement requiring large driving forces or precise intermittent control.

Cautions on adopting intermittent rotary mechanism using friction wheel

Since the rotation force is transmitted by the friction resistance occurred when the driving and driven shafts contact each other on their periphery in this case, care is needed with the following:

(2) Intermittent motion mechanism using friction force

Only two components are required for this mechanism. Both of them are available in the standard components lineup of MISUMI FA mechanical parts. For the driving shaft (1), pulleys for round belts (e.g. MBRM) can be used and a periphery alteration made. For the driven shaft (2), conveyance pulleys (e.g. O-RING type: PFCB or UMHS) can be used.

From the next volume, we will look at typical direction-changing mechanisms that will divert the forces on the driving shaft side.