Precision variable pitch worm gear pair

Precision variable pitch worm gear pairCharacteristics: The meshing principle of precision variable pitch worm gear pairs is the same as that of general worm gear pairs. The axial section of the worm gear is equivalent to a basic rack, and the worm gear is equivalent to its meshing gear. Although the left and right sides of the worm gear teeth have different tooth pitches, the meshing conditions are not destroyed because the tooth pitch on one side is the same. When the worm gear is moved axially, good meshing can also be ensured.

The precision variable pitch worm gear pair is widely used in CNC machine tools with rotary feed motion or indexing motion because it has the outstanding advantage of F.

1. The meshing clearance can be adjusted very small. According to experience, the side clearance can be adjusted to 0.01-0.15mm, while ordinary worm gear pairs can only reach 0.03-0.08mm, which is easy to bite off if laughed at again. Therefore, variable pitch worm gear pairs can work with a small side clearance, which is very beneficial for improving the indexing accuracy of CNC turntables.

2. Ordinary worm gear pairs adjust the meshing clearance by moving the worm in the axial direction, thereby changing the center distance of the transmission pair. From the perspective of meshing principle, it is unreasonable to think that changing the center distance will cause poor tooth contact and even exacerbate wear, which is not conducive to maintaining the accuracy of the worm gear pair. Variable pitch worm gear pairs adjust the meshing clearance by moving the worm in the axial direction, without changing the center distance.

3. Precision variable pitch worm gears use grinding adjustment rings to control the adjustment amount, which is accurate, convenient, and reliable. However, the longitudinal adjustment amount of ordinary worm gear pairs is difficult to grasp, and it is also easy to cause the worm axis to tilt during adjustment.

4. The worm gear of the precision variable pitch worm gear pair is supported on the support, and it is only necessary to ensure that the support centerline coincides with the cross-section of the worm gear. The center distance tolerance can be slightly relaxed. During assembly, an adjustment ring is used to obtain the appropriate meshing clearance, which cannot be achieved by ordinary worm gear pairs.