Definition of a Speed Reducer

by Contributor

Speed reducers are a component of many mechanical, electrical, hydraulic and biological motors. It is easiest to think of a speed reducer as a gear or series of gears combined in such a manner to increase the torque of an engine. Basically, the torque of an engine increases in direct proportion to the reduction of the engines rotations per minute. If you decrease the rotation without slowing down the engine, you increase the force generated. The concept of using gears goes back thousands of years, and the idea of using gears to control torque can be traced at least as far back as the Renaissance period with inventors such as Leonardo De Vinci.


Imagine building an old-fashioned grain mill by alongside a river. You build the mill, install the wheel, and now you have a very rudimentary motor--the spinning wheel. However, there is a problem. The wheel is spinning so fast that you cannot use it. If you try, you risk endangering yourself or ruining the product you built the mill to process. You cannot slow down your engine because your motor is driven by a natural force, the river, so you must instead figure out a means to convert or reduce the speed of the motor to a working speed. The solution is a speed reducer.


The purpose of a speed reducer is not just to increase torque, but to reach the ideal torque for the machine in use. This is done by reducing the speed input rotation to a ratio of "1/X." In this case, "X" represents the reduction ratio. The variable "X" is then multiplied against the torque of the unreduced engine. This gives you the torque of the engine after a speed reducer has been applied to it. That torque can now be applied to drive whatever machine it is intended for.


There are as many types of speed reducers as there are types of gears. Examples of the types gears used to make speed reducers are: • Spur: a gear wheel having radial teeth parallel to the axle. • Worm: a rotating screw that meshes with the teeth of another gear on an inclined plane. • Bevel and spiral bevel gears: a gear wheel that meshes with another at an angle between 90 and 180. The type used depends on the type of engine.


Speed Reducers are used in any industry that uses machinery, whether it is hydraulic or electric. Some examples of uses of speed reducers are in running conveyor belts, medical machines, food processors, printing devices, computers, automotive engines and construction-related machinery.


The type used is dependent on the type of engine, and when replacing a worn-out gear, it is important to replace the reducer with the same type used by the original equipment manufacturer, or seek expert advice.

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