Backlash in Bevel and Hypoid Gears

摘要

Expert response provided by Dr. Hermann J. Stadtfeld. The normal backlash is determined by clamping pinion and gear in a roll tester. First it must be ensured that pinion and gear are rotated to the so called "tight spot." Because of pinion and gear runout, the difference between tight spot and loose spot may be significant. It is important to determine the minimal backlash, because this is the value that must be properly defined for the operation of the gearset. The tight spot can be found on a manual roll tester by setting the pinion cone to the exact mounting distance and rotating the gear by hand until the first metal to metal contact occurs. Further rotation will show if the gear cone has to be increased or reduced in order to maintain a slight metal to metal contact. The angular ring gear position with the largest gear cone adjustment represents the tight spot. Now, the ring gear cone is adjusted to the correct mounting distance and a dial indicator is positioned at the outside in the middle of the profile of a convex ring gear tooth.