Gear Drives

A Gear Drive System is an integrated form of different gears which are arranged in series form. Gear Drive is a system, in which all the require gears are brought under a single system. This Gear Drive system transmits force and motion between two shafts. A motor is required to turn all these gears to do work. There are two gears which are arranged at two opposite ends of the gear box. Gear at the first end which supplies power, is called as Input Gear and gear at the other end of the gear drive system is called as Output Gear. The output gear does the actual work of the gear drive system.


Following are the major Gear Drives:

Selection: Gear Drive System
The reliability of a Gear Drive system depends upon its quality of components, accurate assembly of these components and solid design. The proper combination of all these things makes it an accurate and precision system. A complete and efficient selection process is required for proper gear drive application, and various operating parameters influence the selection process. These operating parameters include load demand, duty cycle, external loads, input power, system accessories, facility needs and environment. A Service factor is another factor on the basic of which the selection of the drive is determined. This service factor accounts for the varying of torque by the driven machines and the driving gear.

Application of Gear Drive in Cars
In a car, first, the motor turns the shaft which is attached to the gears. So, the gears also start to turn one after another. Gradually, this turning process passes from one gear to another. When, the last gear a starts to turn which is attached to the car's axle, the axle starts to move. As a result, the wheels of the car start to move. This is how a gear system moves a car.

Where: Sm = Motor Speed, rpm Sl = Load Speed, rpm Nl = Number teeth on load gear Nm = Number teeth on motor gear N = Gear Ratio Tm = Torque of Motor, lb-in Tl = Torque of Load, lb-in e = Efficiency Jl = Load Inertia, lb-in.-sec2 Jm = Drive Motor Inertia, lb-in.-sec2 Jr = Reflected Load inertia Jt = Total Inertia, lb-in.-sec2

Calculation of Inertia of Gear Drive
If any change takes place in the rotational speed of the gears in the Gear Drive, the load inertia will return back to the motor through the gears. The inertia of a gear drive system can be calculated with the help of the following equation.