Amacoil/Uhing has announced a linear speed control option for Model RG rolling ring linear drives. Normally, the drive moves on a driven shaft with linear speed being adjustable via a pitch control lever located on the drive unit. Now, for applications that do not require variable speed, the new option lets users fix a specific linear travel speed in one or both directions of travel. The fixed travel speed is achieved using set screws which Amacoil inserts into the drive housing. No adjustments to motor speed or controls are necessary.

On a standard Uhing RG drive, the linear speed is adjustable, independently of motor speed, using the pitch control lever on the drive unit. When the set screw option is used, extra long hex head screws are inserted into one end of the drive unit. The end of the screw protruding into the drive unit contacts the rolling ring bearing assembly and holds it at a specific angle relative to the shaft. This gives the drive a fixed linear speed in one direction.
If one set screw is used, the adjustable speed function via control lever may still be used for the other travel direction. If this is not necessary, and a fixed speed in each direction of travel is desired, then two set screws are inserted into the drive housing. In this case, the pitch control lever and dial are removed and the specific pitch/speed of the drive unit is fixed in each direction of travel. The linear speed in each direction of travel may be the same or different depending on application requirements.  

Linear motion system designers may use the set screw option in applications where the return stroke of the drive unit is to bring the drive to a home position. For example, in pattern winding of a fiber, the fiber guide may be moved at a specific speed for the fiber lay down stroke, creating the desired spacing between the rows. A single set screw may be used to cause a rapid return to home position to set up the drive unit for the next layer of fiber. Another application example is applying rows of adhesive. Two set screws might be used to cause the drive to move the adhesive applicator at different rates of speed in each direction of travel. A slow deliberate travel speed might be used while the adhesive is being applied in one direction followed by a slower or faster return.
Based on application needs, Amacoil will work with customers to determine custom settings for the set screw speed control option. The option is inexpensive (less than $100.00) and is easily retrofitted to existing Uhing linear drive set ups. Once the set screw is in place it should not be changed by the user. Changing the depth of the set screw will change the travel speed of the drive unit.

The Uhing drive unit runs on a smooth shaft. There are no threads where dirt and debris can collect which minimizes the chances of jamming or clogging. Amacoil designs and builds linear or traverse drive assemblies for a wide range of positioning and reciprocating motion applications. Uhing drive units provide from seven to eight hundred pounds of axial thrust. Travel spans range from a few inches to several feet. Linear movement is backlash-free.