Parallel shaft gear (cylindrical gear)
(1) Spur gear: a straight cylindrical gear whose tooth ribs are parallel to the axis.
(2) Rack: the linear strip gear engaged with spur gear, which can be said to be a special case when the pitch of the gear becomes infinite.
(3) Internal gear: the internal gear of the straight cylinder that engages with the spur gear.
(4) Helical gear: cylindrical gear with helioid ribs.
(5) Helical rack: a linear gear engaged with a helical gear.
(6) Double helical gear: the helical gear formed by left and right spiral bars.
Gear of straight cross shaft (bevel gear)
(1) Straight bevel gear: the bevel gear with the same tooth rib and pitch cone bus (straight line).
(2) Spiral bevel gear: the tooth rib is the bevel gear with the curve of spiral angle.
(3) Zero bevel gear: the bevel gear with zero spiral angle.
Gears of misaligned shafts (worm gear and worm)
(1) Worm gear: the cylinder worm gear is the general term of worm and wheel.
(2) Cross helical gear: This is a cylindrical helical gear, which is called when it is driven between the shafts to be cross (also known as skew shafts).
(3) Other special gears:
Face gear: a disc-shaped face gear that can engage with a spur gear or a helical gear.
Concave worm gear: the general name of concave worm and the gear engaged with it.
Hypoid gear: a bevel gear that conveys a misaligned shaft. The shape is similar to the bevel gear with curved teeth.