Introduction of Power Transmission Methods

Intro:- Power transmission is process to transmit motion from one shaft to another shaft by using some connection between them like Belts, Ropes, Chains and Gears.

Mainly two types of connectors are used :- 

  1. Flexible (Ropes)

  2. Rigid (Chain, Gears and Shafts)

"In this topic we are only discuss about Flexible Transmission methods"

1. Ropes and Belts are used when Driving and Driven shafts at a large distances (10 to 30 m)

so, this types of power  transmission methods are used.

• Belts and Ropes are non positive power transmission methods ( due to sliping of Rope and Belts on a rotating Pulleys)

Types of Power Transmission in Belts and Ropes

1. OPEN  BELTS SYSTEM :- In open belt drive, belt proceeds from top of one pulley to the top of other pulley without crossing.

•  In open belt drive, driving shaft and driven shaft rotate in same direction.

 2. CROSS BELTS SYSTEM:- In crossed belt drive, belt proceeds from top of one pulley to the bottom of other pulley and thus crosses itself.

•  In Cross Belt drive, driving shaft and driven shaft rotate in opposite direction.

Velocity Ration Formula 

  V= r ✕ ω ( r is the radius of pully and ω is the angular velocity)

 = ω = 2πN/60 ( N is the no. of revolution per min.)

V1/V2 = r1.ω1/r2.ω2  =  r1.N1/r2.ω2 = 2r1.N1/ 2r2.ω2 (twice of pulley radius is equal to Diameter of pulley)

D1.N1/D2/N2 =  D1/D2 = N2/N1

Material Regarding

1. Flat Belts:- Leather, Canvas, Rubber. This is used when driving and Driven shafts at a large distance(10 m).

• Linear velocity of power transmission in Flat Belts is 22 m/sec.

2. V Belts:- In V belts the cross section of belts of belt in V shape, generally made up of rubber.

This is used when driving and Driven shafts at a distance is (4 m)

                        

• Linear velocity of power transmission in V Belts is 24 m/sec.

3. Ropes:- Ropes are generally made up of Cotton & Wires (steel). It is used when driving and driven shaft at  a distance 30 m.

• Linear velocity of power transmission in Ropes is 3 m/sec.

Types of Pulleys

Pulleys are interconnected with both Driving and Driven shaft. 

 

1. Ideal Pulley has no mass and no friction. The tension of ideal cord that runs through an ideal pulley in the same on both the sides of the pulley.

IDEAL PULLEY

2. Intermediate Pulley:- Those pulleys are interconnected.

3. Guide Pulley:- A pulley for directing or changing the line of motion of belt an idler.

I,II,III are idler pulley used to Guide belts at certain angels

we will Discuss about Topic of Gears for Power transmission systems in next part.