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What is drawbar pull

jullah2009

Member
Joined
Nov 11, 2010
Messages
8
Location
dubai
hi everybody,
hope all r fine.Can aby one explain abour drawbar oull,how we can calculate the drawbar pull, what it is mean,for CAT dozer D10R and D10N undercarriage is same, but drawbar pull is different can anybody explain the concept?
 

cummins05

Senior Member
Joined
Jan 3, 2009
Messages
430
Location
Edmonton
it is how much the tractor can pull with it's tractive power

weight power and traction affect it so if the R has more power and weight and traction it will pull more
 

RDG

Senior Member
Joined
Aug 3, 2007
Messages
317
Location
Qld Australia
Occupation
Multi skilled plant operator for 40+yrs
Simply put its what a machine can pull in relation to what it weights depending on the coefficent of friction. If a performance chart shows a machine has a D/B pull of 40,000kg at stall or zero ground speed but weights 25,000kg then depending on the coefficent of friction it might only pull 90% of its operating weight or about 20,000kg. A lot depends on the ground conditions etc, the Cat performance hand books have a good explanation of it all if you can get your hands on one. Cheers RDG.
 

watglen

Senior Member
Joined
Apr 3, 2009
Messages
1,314
Location
Dunnville, Ontario, Canada
Occupation
Farmer, drainage and excavating contractor, Farm d
I think the drawbar pull numbers are a calculated figure based on this sort of thing.

Take the max torque the engine can deliver, do a bunch of math to figure out how much torque will be developed at the drive wheels, then do some more math to figure out how much pull all that torque will deliver to the drawbar.

In theory, you should get that pull if the tracks are fastened solidly to the ground.

It also gives a sense of how much engine torque is lost through the transmission etc.
 

Hjolli

Well-Known Member
Joined
Jan 23, 2007
Messages
124
Location
Iceland
Well, all this math has been done for you in the respective brochures and performance handbooks. That drawbar pull will however assume full traction (coefficient of traction=1)
 

Huntoon

Senior Member
Joined
Mar 14, 2012
Messages
265
Location
California
Occupation
Sales Engineer. I design OEM tracked undercarriage
Drawbar pull is the tractive effort minus the rolling resistance.


Rolling resistance is vehicle weight times rolling resistance coefficient( for example 0.1)
Tractive effort is calculated by taking the torque at the final drive and dividing the pitch radius of the sprocket for tracks or the rolling radius for tires.


For example, a final drive has 60,000 lb in of torque. Tire rolling radius is 20 inches. Vehicle weight is 10,000 lbs
RR= 10,000lbs*0.1=1,000 lbs Rolling Resistance
TE= 60,000lbin/20in = 3000lbs tractive effort
DBP= 3000lbs-1000lbs = 2,000 lbs drawbar pull.

Meaning, you can pull something that resists with a force upto 2,000 lbs.
 
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