A comparative investigation of meshing characteristics of anti-backlash single-and double-roller enveloping hourglass worm gears

Abstract

The new precision transmission system-Anti-backlash roller enveloping hourglass worm gears are now widely employed in many industrial sectors such as robot joint design, packaging production line, and CNC (computer numerical control) machine tools. Therefore, it is of great interest to have knowledge of their corresponding transmission principles that are seldom discussed in the literature. Using the theories of differential geometry and gear meshing, the objective of this paper is to analyze and compare meshing characteristics of anti-backlash single- and double-roller enveloping hourglass worm gears in terms of their transmission principle, engagement equation, induced normal curvature, lubrication angle, autorotation angle, entrainment velocity, helix angle, and distribution of contact curves. The major differences between these two roller enveloping hourglass worms are theoretically investigated in this work. Our results show that the anti-backlash single-roller enveloping hourglass worm (ASEHW) gears provide better performance with respect to gear meshing and transmission than the anti-backlash double-roller enveloping hourglass worm (ADEHW) gears. In addition, compared with the ADEHW gears, the ASEHW gears are easier to fabricate, install, and calibrate. However, the ADEHW gears are more auto-adjustable in eliminating gear backlash. Our study puts forward a theoretical background for futuristic design, application, and promotion of the anti-backlash roller enveloping hourglass worm gears.

Keywords

• anti-backlash single-roller enveloping hourglass worm (asehw) gear
• anti-backlash double-roller enveloping hourglass worm (adehw) gear
• tooth contact analysis (tca)
• backlash
• gear engagement