Miter gears are a single kind of bevel gears where in fact the two rotational axes intersect. When talking about narrow definition of bevel gears with miter gear ability to increase or lower speed, miter gears don’t have that ability because of the pair’s same number of tooth. Their purpose is limited to the change in transmission direction. Because they are a kind of bevel gears, the essential characteristic of bevel gears exist such as presence of gear forms of straight cut, spiral lower and types.
Also, since the shafts can be set to any kind of angle, now there are miter gears with non-90 degree (non-perpendicular) angle called angular miter gears. Ever-power is capable of making angular miter gears with shaft angles in the range of 45 to 120 degrees.
Because a couple of straight tooth miter gears has the same amount of teeth, apart from small differences such as set screw holes and key ways, the same two gears can mate with each other. However, in the case of spiral miter gears, even when the amount of teeth are the same, the twisting directions will vary. Therefore, the same equipment can’t be meshed together, and it is necessary to pair the right and left handed pairs.
Bevel gears are classified in different types according to geometry:
Right bevel gears have conical pitch surface area and teeth are direct and tapering towards apex.