Unformatted text preview: to contact W t × P W t , and SI: s = FW × Y m × FW × Y t where W , P, m, FW and Y are tangential force, diametral pitch, module, face width and Lewis factor. (Similar expressio ns in sect ion 141 of Budynas) Y the Lewis factor o Based o n d iametral p it ch o r mo du le Y = py = p(2x/3p) o Fu nct io n o f toot h shape ( no t size) o Var y wit h nu mber o f t eet h in t he gear Bending stress fro m Lewis equat ions, Imperial: s = AGMA EQUATIONS o AGMA (Amer ican Gear Manu fact urers Asso ciat io n) int ro duces several fact ors to t ake acco unt fo r different issues for design and analys is o AGMA considers bot h bend ing failure a nd p it t ing failure (see Hert z t heory in sect io n 142 Bud ynas) o AGMA considers not o nly st ress, but also st rengt h The relevant equations for spur gear, helical gear and bevel gears are similar. (See chapter 14 and 15 for details). Here straight bevel gear will be used to demonstrate the relat ively detailed informat ion. 8 MECH323 – 2007 GEARS______________________...
View Full Document
- Fall '09
- gear, po int, pitch diameter, ang le, Pitch circle Pitch