| Improved Gear Shapes for Face Worm Gear Drives |
|
|
| John H. Glenn Research Center, Cleveland, Ohio | |
| Jun 01 2006 | |
|
Page 2 of 2
advertisement:
The main advantage of using tilted head cutters is that cutting speeds are independent of the shape-generation processes, making it possible to choose cutting speeds that are optimum with respect to requirements to minimize temperatures and deformations during fabrication and improve the quality of finished parts. The profile of the cutting or grinding surface and the machine-tool settings for the position and orientation of a head cutter would be derived from the theoretical shape generated by a hob. The derivation would be effected by use of an algorithm that takes account of the tilted-head-cutter geometry and enforces the requirements for meshing and non-interference. A tooth-contact-analysis computer program has been developed for simulation of meshing and contact of the proposed worms and face worm gears. In a test case, the program showed that, as desired, the function of transmission errors would be a parabolic function of low magnitude, the contact would be localized, and the path of contact would be longitudinal in the sense that it would lie along the gear-tooth surfaces. The program also showed that the bearing contact region would be free of areas of severe contact stresses and that the contact ratio would be larger than 3 (signifying that at any given instant, there would be at least 3 pairs of teeth in contact). This work was done by Faydor L. Litvin, Alessandro Nava, Qi Fan, and Alfonso Fuentes of the University of Illinois for Glenn Research Center. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Mechanics category. Inquiries concerning rights for the commercial use of this invention should be addressed to NASA Glenn Research Center, Innovative Partnerships Office, Attn: Steve Fedor, Mail Stop 4–8, 21000 Brookpark Road, Cleveland, Ohio 44135. Refer to LEW-17596-1. This Brief includes a Technical Support Package (TSP).
Improved Gear Shapes for Face Worm Gear Drives (reference LEW-17596-1) is currently available for download from the TSP library. Login first to download.
|
