KHK USA Inc. (Mineola, NY), a factory-owned distributor of the KHK brand of metric gears, has announced its innovative Duplex Worm Gears, engineered to streamline the adjustment of backlash in worm gear assemblies. Unlike conventional systems requiring alterations to the gearbox housing, KHK’s duplex solution enables easy, precise backlash adjustments through simple axial movement of the worm shaft, reducing both installation time and maintenance complexity.
Duplex worm gears incorporate a unique dual-lead tooth profile. By forming a difference between the right and left tooth surfaces, the tooth thickness varies continuously along the worm, allowing fine backlash adjustment as the worm moves axially. This precise movement ensures optimal gear engagement without the need for labor-intensive rework, as adjustments made by shifting the worm axially eliminate the need for major gearbox rework. Tooth thickness variation enables continuous control over backlash; moving the worm in the arrow’s direction brings thicker teeth into mesh and reduces backlash. Each 1 mm shaft shift typically reduces backlash by 0.02 mm, providing reliable and predictable results.
Duplex Worm Gears from KHK USA are designed for easy integration in multiple assembly styles, including screw- and shim-based adjustment layouts. Clear visual arrows and reference grooves on both the worm and worm wheel ensure intuitive installation and precise backlash control. The gears achieve near-zero backlash (±0.045 mm tolerance) when properly aligned with the designated reference marks and set to the specified center distance.
