Assembly in Action: Tolerance Rings Give Company Competitive Edge
Many companies have turned to tolerance rings after years of struggling with the mess and cure time of epoxy or the uncertainty of a setscrew. The tolerance ring allows for one-step assembly that retains the brush holder in its axial and radial position, and extends the motor's brush life.
For many of its motors, the company uses the traditional assembly method, which involves a BN-style ring, whose ends overlap in the free state. The ends of the ring are pulled apart and placed over the brush holder body, allowing for a small gap be-tween the ring's end. The ring is pushed axially until it rests against the brush holder's shoulder. The entire brush holder assembly is then inverted and pressed into the hole in the motor OD.