Compound Gear train

Compound Gear train

1. COMPOUND GEAR TRAIN By Avinash N. Fulbaria

2. Content Introduction Applications Types of Gear Train Introduction to Compound Gear Train Equation Derivation for Compound Gear Train. Reference

3. Introduction A gear train is a combination of gears used to transmit motion and power from one shaft to another It is also known as train of toothed wheels Gear trains may use spur, bevel or spiral gears.

4. Applications Used to either speed up or stepped down the speed of driven shaft and follower. Examples :- 1) Automobile 2) Clocks 3) Ships 4) Watches 5) Lathe Machines etc.

5. Types Of Gear Trains Simple gear trains Compound gear trains Riveted gear trains Epicyclic gear trains

6. Compound Gears Introduction Each of the intermediate gears carries two gears except the driving and driven shafts. Examples :- used in headstock of lathe machine.

7. Equation Derivation for Compound Gear As gear A drives gear B . Gear C is rigidly mounted on gear on the axis of gear B so speed will be same. Gear C drives the gear D

8. 1) For gear A and B : NB ∕ NA = tA ∕ tB = dA ∕ dB….(1) 2) For gear C and D : ND ∕ NC = tC ∕ tD = dC ∕ dD…(2) Multiplying (1) and (2) NB ∕ NA × ND ∕ NC = tA ∕ tB × tC ∕ tD = dA ∕ dB × dC ∕ dD

9. But NB = NC (Since gear B and C are fixed on same shaft ) Therefore, Velocity ratio, ND∕ NA= tA ∕ tB × tC ∕ tD = dA ∕ dB × dC ∕ dD

10. ND∕ NA= Product of number of teeth on drivers Product of number of teeth on followers ND∕ NA = Product of diameters of drivers Product of diameters of followers

11. Advantages 1) Higher and lower velocity ratio can be obtained . 2) Velocity ratio for the given distance between driving and driven shaft can be obtained.

12. Reference Kenneth J. Waldron, Gary L. Kizel , Kinematics, Dynamics and Design of Machinery ,Second Edition, 2010

13. END