With the Okcoil traverse unit (ring linear drive), changes to travel direction and linear motion speed are both adjustable regardless of the rotational direction or speed of the drive motor. This purely mechanical control over travel direction and linear motion speed makes it easier to meet linear motion control application requirements when compared to systems that require designing-in clutches, brakes, gearboxes, servo motors and complex control systems. It also minimizes operating and maintenance costs. And because rolling ring rotary to linear motion systems operate continuously even when changing direction or pitch, production rates and throughput improves.
A rolling ring linear drive is typically supplied within a production framework which is "dropped" into the manufacturing equipment. Adjustable end stops come installed on the assembly to control stroke length. When the linear drive traverses to the point where the mechanical reversal mechanism reaches an end stop, the reversal mechanism is turned and the drive reverses itself automatically.
Inexpensive and simple hardware modifications to the end stops and mechanical reversal mechanism, facilitate changes to the linear drive's travel direction and linear speed. This is useful to meet application requirements for ramping up/down and dwell. The most typical application requirements are:
- Ramping down before reversal
- Ramping up after reversal
- Ramping down before reversal and ramping up after reversal
- Dwell (ramp down to a complete stop)
Normally, the okcoil reversal mechanism is actuated when it contacts an end stop, and automatic, instantaneous reversal occurs. Attaching the lever and modifying the end stops, however, permits controlled, slow rotation of the rolling ring bearing assembly within the housing or nut. The leading end of the lever contacts the end stop before the reversal mechanism does. The lever is turned and the rolling ring bearing assembly is partially rotated. That is, the bearings are slowly turned so they are more perpendicular to the shaft. This will decrease the drive's linear speed. If the bearings are moved so they are perpendicular to the shaft, the drive dwells on the shaft while the motor continues to operate.