Practical methods to control gear whine in transmission manufacturing process
Gear whine of automotive transmissions should be controlled since it is of a nuisance. While many methods are used to control gear whine at gear design stage, this paper deals with it in transmission manufacturing process including gear manufacturing and transmission assemblies. There are high percentages of effects on transmission error and gear whine in these two processes. Idle gear whine noise can be reduced by the introduction of hard finishing which can optimize the gear shapes and surfaces. Bending of helical gear is found playing an important role in generating high frequency gear whine. It is significant for transmission assemblies to study the correlations of End of Line (EOL) and vehicles. The satisfying correlations can identify and control gear whine of an assembled transmission. All the methods mentioned above have been applied in transmission manufacturing process and good results have been achieved.
Optimum Profile Modifications for the Minimization of Static Transmission Errors of Spur Gears
A procedure for computing static transmission errors and tooth load sharing was developed for low and high contact ratio internal and external spur gears. A suitable optimization algorithm was used to minimize any combination of the harmonics of gear mesh frequency components of the static transmission error. Different combinations of tip and root relief may be used to achieve optimization. These include varying the starting point of relief and varying the magnitude of relief, and selecting the gear and/or the pinion teeth to be tip and/or root-relieved. Also, there exists an option for using either linear or parabolic relief. In addition to the presentation of optimal profile modifications, the effects of off-design loads, nonoptimum modifications, and random spacing errors are presented.
Bending Stresses in Spur Gear Teeth: Proposed New Design Factors Based on a Photo-elastic Investigation:
The paper embraces three related subjects: Photo-elastic measurement of stresses in spur gear teeth; interpretation of stresses so found to give revised strength factors for B.S. specification on the design of spur gears; and a tentative attempt to correlate the stresses found with fatigue-test results which have been reported by various investigators.The object of this paper is to propose maximum safe bending loads which involute spur gears can be allowed to carry. The gears investigated are confined to those which can be generated by standard cutters conforming to the 20-deg. pressure-angle, B.S. basic rack, without either causing undercutting near the root or undue pointing of the teeth. The values proposed are based on a photo-elastic investigation carried out by the author under the guidance of Professor W. A. Tuplin, at the Post Graduate School of Applied Mechanics, Sheffield University.Strength factors for spur gears are given in the form of charts. These factors embrace the whole possible range of...