上海充通大学 A pair of Gears 01 Segment of action:N,N2 When engaging begins Driver:root→top 口 driven:top→root 口 Engaging begins at:point B2 Engaging ends at:point B Real segment of action:B,B2 「a2 02 02 Real arc of action of the gears 上海充通大粤 A pair of Gears In order to transmit motion smoothly:one tooth is leaving contact after the next engaged. 口condition:B,B2>Pb Contact Ratio: 8=B,B21P6 皿p=Z/P6 in p281 of design of machinery 01 where, Z=+ap)-(rcos)++ag)2-(rgcos)2-C sin in p2724  Segment of action:N1N2  When engaging begins  Driver：roottop  driven：toproot  Engaging begins at：point B2  Engaging ends at： point B1  Real segment of action： B1B2  Real arc of action of the gears rb2 O2 1 2 N2 O1 rb 1 P N1 ra1 ra2 B1 B2 A pair of Gears  In order to transmit motion smoothly:one tooth is leaving contact after the next engaged.  condition: B1B2 > pb  Contact Ratio: O1 O2 1 2 N2 N1 B2 B1 K ra2 ra1 rb1 rb2 O1 O2 N2 N1 B1 B2 P B B pb /  1 2  in p272 Z (r a ) (r os ) (r a ) (r os ) sin where, / in p281 of 2 g 2 g g 2 p 2 p p c  c  C  m p Z p b design of machinery         A pair of Gears