GEAR FUNDAMENTALS The Basics of Spiral （齿轮基本面螺旋的基础知识）.pdf

GEAR FUNDAMENTALS The Basics of Spiral Bevel Gears Dr. Hermann J. Stadtfeld This article also appears derived from a straight rack as Chapter 1 in the with straight tooth profile. A particular gear, rolling in the Gleason Corporation pub - rack with constant center dis- lication “Advanced Bevel tance to the rack, requires Gear Technology.” involute flank surfaces. A shaping tool with the shape of Gearing Principles in a rack can machine a gear with Cylindrical and Straight a perfect involute flank form. Bevel Gears Figure 1 shows a cylindrical The purpose of gears is to gear rolling in a rack. transmit motion and torque To understand the bevel from one shaft to another. That gear tooth geometry, one transmission normally has to might first observe the case of occur with a constant ratio, the straight bevel gears. If the lowest possible disturbances generating rack used to derive and the highest possible effi- the cylindrical gear involute is Figure 2—Crown gear arrangement in bevel gear sets. ciency. Tooth profile, length bent in a horizontal plane into tion point of the pinion and which causes a straight lead and shape are derived from a circular shape, it r