Industrial V Belts

Industrial V Belts

To obtain even distribution of load on a multi V-belt drive the length of V-belt should be matched. A set of such belts, the length of which are within the specified limits, so that these can be used together, is called a matched set. The table given shows the permissible vaiations in consecutive grading numbers marked near the size code which represents the exact length measured under specified operating tensions.

CODING SYSTEMS

When the code number 50 is shown on the cello-+tape affixed on each V-Belt, this indicates that the actual length coincides with the nominal length printed on the belt. Each 2.5mm (1/10) variation from the nominal length is represented by one unit. For example, a V-Belt with size 100 coded 50 is 100 inches inside lenth. If the code is 51 then it is 100.1 inches inside length and if the code is 49 then it is 99.9 inches inside length.

CORRECTION FACTOR FOR SPEED RATIO TO CALCULATE POWER RATING (R)
 

POWER CORRECTION FACTORS FOR INDUSTRIAL SERVICE(Fa)

To correct the horse power rating of the V-Belt Drive for the type of service on which it is to be used, multiply the motor horse power to be transmitted by the power correction factor given below, taking into account the type of driven machine and the operational hours per day.

Special Conditions: For speed-up and reversing drives except where high torque is not present on starting, add 20% to the factors.

• idler pulley on slack side (internal), add 0 to the factors.
• idler pulley on slack side (external), add 0.1 to the factors.
• idler pulley on tight side (internal), add 0.1 to the factors.
• idler pulley on tight side (external), add 0.2 to the factors.

Light Duty : Agitators for liquids, blowers and exhausters, centrifugal pumps and compressors, fans upto 7.5 KW and light-duty conveyors.

Medium Duty : Belt Conveyors for sand grain etc. dough mixers, fans over 7.5 KW; generators; line shaft; laundary machinery; machine tools; punches; presses adn shears; printing machinery; positive displacement; rotary Pumps ; and revolving and vibrating screens.

Hevay Duty : Brick Machinery; bucket elevetors; exciters; piston compressors; conveyors;(drag-pan-screw); hammer mills; paper mill beaters; piston pumps; positive displacement; blowers; pulverizers; saw mill; wood working machinery; and textile machinery.

Extra Heavy Duty : Crushers (gyratory-jaw-roll); mill (ballord-tube); hoists; and rubber (calenders extruders) mills.
 

AC Motors : Normal Torque Squirrel Cage, Synchronous and Split Phase.

DC Motors : Shunt Wound, Multiple Cylinder Internal Combustion Enginees over 600 rev/min

AC Motors : High Torque; High Slip Repulsion Induction; Single Phase Series, Wound and Slip ring.

DC Motors : Series Wound and Compound Wound, Single Cylinder Internal Combustion Engines, Multiple cylinder, Internal Combustion Engines. Under 600 rev/min. Line shafts clutches, Brakes, Direction Line Starting.

Installation of allwyn V-belts

• Always use a matched set of belts for multiple drives.
• It is essential to ensure that correct section and size of V-Belt has been chosen for the drive.
• Whenever V-Belts are used in multiples, matched sets should be used.
• Check bearing for oil.
• V-Belts should be placed in Stretch grooves properly and without any extra strech.
• For this centre distance between sheaves can be shortened by freeing the motor or the driven machine. Application of lever should never be used.
• Keep deflection angle less than 1/3.
• Tension the drive machine. Tension is correct when belts feel alive.
• Don't expose belts to water, oil, chemicals etc.
• Check that V-Belts take proper seat in the V Pulley