The SBGTAPER computer program implements a method for design and generation of spiral bevel gears that feature tapered teeth with localized bearing contact and a low level of transmission errors. The influence of misalignment on transmission errors and shift of bearing contact were investigated in the development of the method.

The SBGTAPER approach emphasizes detection and avoidance (i) of vibration caused by misalignment and (ii) of an edge contact caused by interference between the working part of the surface of a gear with the fillet surface of the mating gear. The main features of this approach are the following:

  1. The localization of the bearing contact is achieved by the mismatch of the generating surfaces. The bearing contact can be provided in the longitudinal direction or in the direction across the surface.
  2. The low level of transmission errors is achieved because of application of nonlinear relations between the motions of gears and of gear-head cutters. Such relations can be obtained from application programs for computer numerically controlled (CNC) machine tools. The generation of a pinion is based on linear relations between the motions of the pinion and of the tool used to make the pinion. These relations make it possible to obtain a parabolic function of transmission errors that can absorb almost-linear functions caused by misalignment.

SBGTAPER is written in FORTRAN 77 for IBM-PC-compatible computers. The IMSL libraries and a FORTRAN compiler are required. No executable code is provided because input data are entered directly into the source code. SBGTAPER has been successfully executed on a 486 computer running Windows 95 with Microsoft Fortran Powerstation 4.0. The standard distribution medium for SBGTAPER is one 3.5-in. (8.89-cm) diskette in MS-DOS format. The contents of the diskette have been compressed by use of the PKWARE archiving software tools. SBGTAPER was released to COSMIC in 1997.

This program was written by F. L. Litvin and A. Wang of the University of Illinois at Chicago and R. F. Handschuh of the Army Research Laboratory forLewis Research Center. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.comunder the Computer Software category, or circle no. 156 on the TSP Order Card in this issue to receive a copy by mail ($5 charge).

LEW-16493

NASA Tech Briefs Magazine

This article first appeared in the March, 1998 issue of NASA Tech Briefs Magazine.

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