7/25/2019 Double Speed by Creep Drive

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creep seed drive

By using creep speed drive, onecan get 2 different speeds (typically lower speed is 10 % of normal

speed) on same shaft. Creep speed drive unit includes different partsassem!led together vi". induction motor, helical gear !o#, electricallyapplied clutch.

$ypical application of this creep speed drive would !e hori"ontal longtravel mechanism of crane. magine that total long travel span of a crane

is &0 feet. 'nd crane operator is reuired to drop (already lifted load) atdistance of th feet.

n order to save time, crane operator will prefer moving load with higherspeed till *th feet. 'nd then from *th feet to th feet he will prefermoving load very slowly (say a!out 10 % of initial speed). Because of

this reduced speed, he will !e a!le to drop load at e#act th feet. Creepspeed drive is often used in this type of application.

+henever lower speed is reuired, main electric motor is switched off

and clutch is engaged. $his clutch connects helical gear!o# to drivenshaft. ow creep speed motor is ready to move load.

-lease note that helical gear!o# is having speed ratio of a!out 10. i.e

elical gear !o# output speed is 10 times slower than input speed.

$herefore creep speed motor runs at synchronous speed and drivenshaft rotates at 10th motor speed. Because of high speed ratio of helical

gear !o# , creep speed drive is self loc/ing. $his feature is veryimportant (say in a case of heavy load !eing lifted) for safety aspect.

AVAILABLE COMBINATIONS OF SPEED RATIO AND MAIN MOTOR

POWER

\

GEAR BOXOUTPUT SPEED INRPM

MAIN MOTORSPEED IN RPM

MAIN MOTOR POWER IN HP

0 0 0.*,1,1.*,2,,*,.*,10,1*,20,2*1*0 1*00 0.*,1,1.*,2,,*,.*,10,1*,20,2*

0 *0 0.*,1.*,2,,*,.*,10,1*