Page 187 - Root Cause Failure Analysis
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GearboxeslReducers     175












              Fiere 14-3  Rack or straight-line gear (Neale 1993).





              from the sliding contact of the meshing teeth. A disadvantage, however, is the higher
              friction and wear that accompanies  this sliding action.

              Single helical gears are manufactured with the same equipment as spur gears, but the
              teeth are cut at an angle to the axis of the gear and follow a spiral path. The angle at
              which  the  gear  teeth  are  cut  is  called  the  helix  angle,  which  is  illustrated  in
              Figure 14-5.  This angle causes the position of tooth contact with the mating gear to
              vary at each section. Figure 14-6  shows the parts of a helical gear.






































             Figure 14-4  Qpical set of helical gears (Neale 1993).
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