Belt Drives and Chain Drives www.engineersportal.in

CONTENTS Introduction. Overview: Why Used? Belt Drives. Types of Belt Drives. Design for Belt Drives. Chain Drives. Terminology for Chain Drives. Difference B/W Belt Drives & Chain Drives. Conclusion www.engineersportal.in

INTRODUCTION The belt drives or chain drives are mainly used for transmitting the power from one shaft to other when they are running at different speed or either at same speed . www.engineersportal.in

Overview – why used? Transfer power or torque from one location to another i.e. From driver: motor, peddles, engine, windmill, turbine to driven: conveyor belt, back wheels/ bike. Used to span large distances. Gear drives have a higher torque capability but not flexible or cheap. Often used as torque increaser & speed reducer, max speed ratio (3.5:1). When Positive drive is required. www.engineersportal.in

BELT DRIVES This are the power transmitting device. This is based upon the velocity of belt, arc of contact b/w belt & smaller pulley. Material used for belt may be leather, cotton, rubber etc. Slip & creep. www.engineersportal.in

TYPES OF BELT DRIVES *A/C to velocity of drive *A/C to geometry *Light *Flat belts *Medium *V- belts *Heavy *Trapezoidal *Curvilinear & Rounded www.engineersportal.in

TRAPEZOIDAL & curvalinear Belt Drives www.engineersportal.in

Round & timing type belt drive www.engineersportal.in

V-Belts Drive 1. COVER 2. INSULATING COMPOUND 3.TENSION MEMBER 4. COMPRESSION AREA www.engineersportal.in

ADVANTAGES & DISADVANTAGES Positive drive due to no sleep. High velocity ratio is high (10). More power transmission Longer life. DISADVANTAGES Complicated construction. Not to be used in large center radius. Produce certain amount of creep. www.engineersportal.in

DESIGN FOR BELT DRIVES Belt speed (no slipping) Speed ratio Pitch dia. of sheaves www.engineersportal.in

CONTI……. Belt length: (Open belt drives) Center Distance: www.engineersportal.in

Angle of contact b/w pulleys Size Size Center Distance (center shaft to center shaft) Motor Nameplate www.engineersportal.in

TYPES OF FLAT BELT DRIVE *opEN BELT DRIVE www.engineersportal.in

Cross belt drive www.engineersportal.in

CHAIN DRIVES To avoid sleep & creep used steel chain. Perfect velocity ratio is obtained. Used for both long & short length. Produce less load on shaft & more power. Withstand at any temperature & atmospheric condition. www.engineersportal.in

TERMINOLOGY PITCH SPROCKETS PITCH CIRCLE DIAMETER. www.engineersportal.in

Chain Drives design Calculate Velocity Ratio n = speed T = teeth www.engineersportal.in

where Length of chain drives www.engineersportal.in

CLASSIFICATION OF CHAIN Hoisting & hauling(with square & oval links). Conveyor chain (hook joint & closed joint type). Bush roller chain www.engineersportal.in

COMPARISION BELT DRIVE CHAIN DRIVE Used When: Speed: Dis: Advs: High Speed, Low T High T, Low Speed Speed: 2500 < Vt < 7000 ft./min. V < 1500 ft./min. Must design with standard lengths, wear, creep, corrosive environment, slip, temp., when must have tension need idler Must be lubricated, wear, noise, weight, vibration Dis: Strength, length flexibility Advs: Quiet, flexible, cost www.engineersportal.in

conclusion www.engineersportal.in

IF ANY THANKS FOR YOUR ATTENTION www.engineersportal.in