Usually, the method of adjusting the backlash of the worm gear is to change its assembly distance. If you want to change the assembly distance after assembly, you need to make significant adjustments to the gearbox and other components. However, if a precision gapless dual lead worm gear pair is used, the backlash can be adjusted without changing the assembly distance of the gearbox, making assembly and maintenance very convenient. Because the precision gapless double lead worm gear pair is a special product, please read the following explanation before using it, and fully understand its function and structure before use.

Construction and adjustment method of side clearance adjustment

The left and right tooth surfaces of the worm have different lead distances. Due to the lead difference, the shape of the gear teeth is a tooth profile with continuous thickness variation. (Figure 1)

The teeth of the worm gear are also processed with different tooth surfaces on the left and right sides, just like the worm gear. However, because the worm gear is a cylindrical gear, the tooth pitch of all teeth is equal.

Assembly precautions
Due to the different modulus of the left and right tooth surfaces of the dual lead worm gear, it is necessary to assemble it correctly to ensure proper meshing between the worm and the worm gear. In order to avoid errors in assembly direction, assembly position, etc., please first confirm the following items and assemble the worm gear correctly.
1. Confirmation of assembly direction
The double lead worm and worm gear products are engraved with arrow markings indicating the assembly direction. When assembling, first confirm the front and back of the worm gear, and the assembly direction should be consistent with the arrow direction of the worm gear and worm gear. Incorrect assembly direction can cause the center distance a to be greater than the standard distance, resulting in inability to assemble or engage correctly. (Figure 3)

2. Confirmation of assembly reference position
The outer circumference of the tooth tip circle of the double lead worm is engraved with a V mark (a line with a depth of 0.3mm at 60o), which represents the reference tooth. When aligning the reference teeth with the rotation center of the worm gear and assembling them according to the standard center distance a, the backlash is designed to be 0 (± 0.045). (Figure 4)

Product feature precautions:
Vmax is the maximum movement distance when the worm gear is moved in the direction of reducing backlash based on the reference tooth position, and there is no problem with meshing with the worm gear. Not the recommended value for assembly.
The tolerance of the shaft diameter dimension of W6 shape is S (+0.10+0.20) (the grinding part is S (+0.35+0.40))

Product feature precautions:
1. The allowable torque value is a reference value calculated under any usage conditions.
2. When assembling the double lead worm gear, it is necessary to install it in the direction of the arrow indicated by the worm and worm wheel. The arrow direction of the worm gear only indicates the assembly direction and does not limit the rotation direction.

Product feature precautions:
Vmax is the maximum movement distance when the worm gear is moved in the direction of reducing backlash based on the reference tooth position, and there is no problem with meshing with the worm gear. Not the recommended value for assembly.
The tolerance of the shaft diameter dimension of W6 shape is S (+0.10+0.20) (the grinding part is S (+0.35+0.40))

Product feature precautions:
1. The allowable torque value is a reference value calculated under any usage conditions.
2. When assembling the double lead worm gear, it is necessary to install it in the direction of the arrow indicated by the worm and worm wheel. The arrow direction of the worm gear only indicates the assembly direction and does not limit the rotation direction.

Product feature precautions:
Vmax is the maximum movement distance when the worm gear is moved in the direction of reducing backlash based on the reference tooth position, and there is no problem with meshing with the worm gear. Not the recommended value for assembly.
The tolerance of the shaft diameter dimension of W6 shape is S (+0.10+0.20) (the grinding part is S (+0.35+0.40))

Product feature precautions:

1. The allowable torque value is a reference value calculated under any usage conditions.
2. When assembling the double lead worm gear, it is necessary to install it in the direction of the arrow indicated by the worm and worm wheel. The arrow direction of the worm gear only indicates the assembly direction and does not limit the rotation direction.