Straight Bevel Gears

The simplest to produce and widely used conical gear type, the Straight Bevel gears have straight teeth cut along the pitch cone that, if extended, would intersect with the shaft axis The tooth form of a straight tooth bevel gear is effectively that of a spur gear but one whose geometry tapers toward the point of a theoretical cone.

From an engineering point of view, for the blending of gears, both cones must meet at a common point, and for this reason, bevel gears are not interchangeable in the manner of spur gears. These theoretical cones are called the pitch cones.

Another of such theoretical cone is the back cone, which defines the outermost edge of the gear tooth, the largest part of the tooth where the size and shape are specified. Like spur gears, tooth faces usually have a slight crown that lend them more utility.

Sometimes gears of 1:1 ratio is used, just for the purpose of changing the direction. These special cases of bevel gears are called miter gears. Since each gear has the same number of teeth, straight tooth miter gears can be used as interchangeable pairs.