Gears are key components of many motors and machines.Gears can increase torque output by providing gear reduction and adjust the direction of rotation of the shaft, such as the rear wheel of a car.Here are some basic types of gears and how they differ from each other.
Spur gear
The common gear is a spur gear, which is used for gear reduction.The teeth on the spur gear are straight and are installed in parallel on different shafts.Spur gears are used in washing machines, screwdrivers, clockwork alarms, and other equipment.Because of gear meshing and collision, each impact will produce huge noise and cause vibration, which is why spur gears are not used in automobiles and other machinery.A normal gear ratio ranges from 1:1 to 6:1.

Helical gear
由于齿相互作用的原因，斜齿轮与正齿轮相比工作更平稳和安静。斜齿轮上的齿与齿轮表面成一定角度切割。当两个齿开始接合时，接触是逐渐的 - 从齿的一端开始并在齿轮旋转到完全接合时保持接触。典型的螺旋角范围约为15-30度。推力载荷直接随着螺旋角的切线的大小而变化。螺旋是变速器中常用的齿轮。它们还产生大量推力，并使用轴承来帮助支撑推力负载。斜齿轮可用来将旋转角度调整90度。当安装在垂直轴上时。它的正常传动比范围是3：2到10：1。

Bevel gear
Bevel gears are used to change the direction of rotation of the shaft.Bevel gears have straight, spiral or hypoid shaped teeth.Straight teeth and spur gears have similar characteristics, and they also have a great influence when meshing.Similar to spur gears, the normal transmission ratio range of straight bevel gears is 3:2 to 5:1.
The operation of helical teeth is the same as that of helical gears.Compared with straight teeth, they produce less vibration and noise.The right side of the spiral slope is the outer half of the tooth, obliquely traveling clockwise from the axis plane.The left hand of the spiral bevel moves counterclockwise.The normal gear ratio range is 3:2 to 4:1.
Hypoid gear is a type of helical gear whose shape is a revolving hyperboloid rather than a conical shape.Hypoid gears place the pinion gear on the ring gear or crown wheel.This allows the pinion to have a larger diameter and provide more contact area.
The pinion and the gear are always opposite, and the helix angle of the pinion is usually greater than the angle of the gear.Hypoid gears are used in power transmission systems due to their larger transmission ratios.The normal gear ratio range is 10:1 to 200:1.

Worm gear
Worm gears are used to reduce large gears.The transmission ratio range of 5:1 to 300:1 is typical.The purpose of the setting is to allow the worm to rotate the gear, but the gear cannot rotate the worm.The angle of the worm is shallow, so the gear stays in place due to the friction between the two.The transmission device is suitable for conveyor belt systems, where the locking function can be used as a brake or an emergency stop device.