Bevel Gears are conical gears, that is gears in the shape of cones and are used to connect shafts having intersecting axes.
Straight Bevel gears are the most commonly used type of bevel the teeth on the bevel gear are straight but there side a are tapered so that they would intersect the axis at a common point called the pitch cone apex if extended inwards. The face cone elements of most straight bevel gears are made parallel to the root cone elements of the mating gear to obtain uniform clearance along the length of the teeth. The face cone elements of such gears would, therefore, intersect the axis at a point inside the pitch cone.
Straight Bevel gear teeth may be generated for full length contact or for localized contact. The latter are slightly convex in a lengthwise direction so that the same adjustment of the gears during assembly is possible and small displacements due to load deflections can occur without undesirable load concentration on the end of the teeth. This slight lengthwise rounding of the tooth sides need not be computed in the design but is taken care of automatically in the cutting operation on the types of Gleason Bevel generators SBT Gears have on site