Zerol tooth traces
Zerol bevel gears are an intermediate variety in between straight and spiral bevel gears. Their enamel are curved, but not angled. Zerol bevel gears are made with the intent of duplicating the qualities of 
a straight bevel gear but they are developed making use of a spiral bevel reducing method.
china bevel gears
The edge of the spiral tooth in excess of the straight tooth is that they interact much more steadily. The get in touch with in between the tooth starts off at one end of the equipment and then spreads across the whole tooth. This outcomes in a much less abrupt china bevel gear transfer of power when a new pair of teeth occur into play. With straight bevel gears, the abrupt tooth engagement brings about sound, particularly at higher speeds, and effect tension on the tooth which helps make them not able to take hefty hundreds at substantial speeds without having breaking. For these causes straight bevel gears are normally restricted to use at linear speeds considerably less than one thousand toes/min or, for small gears, beneath 1000 r.p.m.[3]
Spiral tooth lines
Main article: Spiral bevel equipment
Spiral bevel gears have their tooth fashioned alongside spiral lines. They are considerably analogous to cylindrical type helical gears in that the tooth are angled even so, with spiral gears the teeth are also curved.
Straight tooth strains
In straight bevel gears the enamel are straight and parallel to the generators of the cone. This is the simplest sort of bevel equipment. It resembles a spur equipment, only conical instead than cylindrical. The gears in the floodgate photograph are straight bevel gears. In straight bevel gear sets, when each and every tooth engages it impacts the corresponding tooth and basically curving the gear enamel can remedy the difficulty.