Duplex Worms Gear

Product Specification

A duplex or dual lead worm gear features a worm with flanks designed with slightly different modules and diameter quotients, creating distinct lead angles on each tooth profile. This results in gradually increasing tooth thickness along the worm’s length and narrowing thread gaps, allowing precise backlash control.

On the worm wheel, the differing modules produce unique addendum modification coefficients and rolling circle diameters on each flank, forming distinct front and rear profiles. However, tooth thickness and gaps remain consistent around the wheel’s circumference.

Backlash is adjusted by axially shifting the worm to align the appropriate tooth thickness with the wheel, achieving the desired backlash level (see fig. 1). This method enables easy, precise backlash tuning during installation and continuous adjustment for worn gears without affecting tooth contact or meshing.

Alternative backlash adjustment methods include: modifying the center distance using an eccentric hub for the worm shaft and wheel; axially moving a tapered worm (fig. 2a); splitting the worm into two parts that can be rotated or shifted relative to each other (Ott system, fig. 2b); or dividing the wheel into two adjustable discs (fig. 2c).

Assembly Caution Note

Our Raydafon Duplex Worms Gear have different tooth moduli on the left and right sides, so the worm gears must be precisely aligned during installation. Here are a few key steps to remember:

Before installation, check the assembly direction mark. Each double worm gear and worm gear has an arrow on it, which is the installation "compass". When installing, from the front, you must ensure that the arrows of the worm gear and worm gear point in the same direction (see Figure 3). If the arrow direction is reversed or misaligned, the center distance of the worm gear will be too large and it will not fit. Even if it is barely installed, the gear meshing will have problems, and it will not take long for the teeth to be knocked or jammed, which will delay things!

Verifying the Reference Position

A V-groove (60°, 0.3 mm deep) on the tip periphery of the duplex worm tooth marks the reference tooth. The gear set achieves near-zero backlash (±0.045) when this reference tooth aligns with the worm wheel’s center of rotation at the specified center distance “a” (see Fig. 4).

Product Features

Raydafon, a long-established manufacturer in the field of mechanical transmission in China, has long been a trusted supplier of many machinery manufacturers by providing customers with high-quality duplex worm gears at affordable prices with the exquisite craftsmanship of its own factory masters. Our products are designed for complex working conditions, and the three core advantages make the operation of the equipment more worry-free.

Dual modulus design, more efficient transmission: Raydafon's duplex worm gears use different moduli on the left and right tooth surfaces, just like installing a "dual engine" on the equipment. High-strength copper alloy worm gears are matched with precision forged alloy steel worms. After eight manual grindings, the bite is tight and does not slip, and the transmission efficiency is 20% higher than that of ordinary worm gears. A textile machinery factory in Zhejiang reported that after replacing our duplex worm gears, the energy consumption of the equipment was reduced a lot.

Two-stage transmission, high torque and low noise: The unique two-stage transmission structure doubles the torque of duplex worm gears, while keeping the running noise even lower. Whether it is the precision fine-tuning of heavy machine tools or the continuous operation of large conveying equipment, it can be easily handled. A food processing factory in Guangdong said that the equipment used to make a lot of noise when running, but after changing to our products, the workshop is much quieter.