Unformatted text preview: k, but tends to push gears apart. tan f n The components are related by: W r = W t × tan f , W a = W t × tany , (Note: tan f = ) t t cosy Where f , f ,y are pressure angle in rotation direct ion, pressure angle in normal direct ion and t n helix angle. The total acting force between the mating gears is W = (W t ) 2 + (W r ) 2 + (W a ) 2 The transmitted power is similar to Spur gears’ given above. Bevel Gears (straight bevel gears): the commo n practice is to use the tangent ial or transmitted load that would occur if all the forces were concentrated at the midpo int of the tooth. While the actua l resultant occurs somewhere between the midpoint and the large end of the tooth, there is only a sma ll error in making this assumpt ion. 7 MECH323 – 2007 GEARS____________________________ (a). W t tangential co mponent W t × V power transmitted V pitch line velocit y at midpoint of teeth V = pd avg n / 60000 [m/s], where davg, pitch diameter at midpoint of teeth, in mm, n, rev/min o r V = pd avg n / 12 [ft/min], where davg pitch diameter at midpoint of teeth, in inch, n, in rev/min (b). r , W a are...
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- Fall '09
- gear, po int, pitch diameter, ang le, Pitch circle Pitch