Influence of tooth modifications on tooth contact in face-hobbed spiral bevel gears

• Published in: Mechanism and machine theory 2011-12, Vol.46 (12), p.1980-1998
• Main Author: Simon, Vilmos V.
• Format: Article
• Language: English
• Subjects: Applied sciences; Computer program; Contact; Contact potentials; Curvature; Drives; Exact sciences and technology; Gears; Machine tools; Mechanical engineering. Machine design; Pinions; Spiral bevel gears; Teeth; Tooth contact; Tooth modifications
• ISSN: 0094-114X; 1873-3999
• DOI: 10.1016/j.mechmachtheory.2011.05.002

In this study the influence of tooth modifications induced by machine tool setting and head-cutter profile variations on tooth contact characteristics in face-hobbed spiral bevel gears is investigated. The concept of face-hobbed spiral bevel gear generation by an imaginary generating crown gear is applied. The modifications of tooth surfaces are introduced into the teeth of both members. The lengthwise crowning of teeth is achieved by applying a slightly bigger radius of lengthwise tooth flank curvature of the crown gear generating the concave side of pinion/gear tooth-surfaces, and by the variation of machine tool settings in the generation of pinion/gear teeth. The ease-off in the tooth height direction of meshing tooth surfaces is achieved by applying a head-cutter whose profile consists of two circular arcs, instead of a straight-line. The method of tooth contact analysis applied determines the path of contact, the potential contact lines, the separations along these lines, and the transmission errors. A computer program implements the method. By using this program the influence of the variation of machine tool settings and of head-cutter geometry on tooth contact is investigated and discussed. ► The concept of face-hobbed spiral bevel gear generation by an imaginary generating crown gear is applied. ► The modifications are introduced into the teeth of the pinion. ► The lengthwise crowning of teeth is achieved by the variation in machine tool settings. ► The ease-off in the tooth height direction is achieved by applying curvilinear head-cutter profile. ► The tooth modifications are optimized.