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472H Potato Harvester Owner Operator’s Manual
Note:
Complete harvester speed calculator is available at
www.lockwoodmfg.com/chainspeed.html
Table # 3 Primary and Secondary Speed
EQUATION:
The following equation can be used to calculate the primary and secondary belted chain speed for the 472H.
PRIMARY BELTED
CHAIN SPEED (MPH) = ((PTO RPM)(# HEX SPROCKET TEETH)(# WEB SPROCKET TEETH)(WEB PITCH))
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SECONDARY BELTED
CHAIN SPEED (MPH) = ((PTO RPM)(# HEX SPROCKET TEETH)(# WEB SPROCKET TEETH)(WEB PITCH))
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EXAMPLE:
GIVEN: In this example we will use a tractor PTO rpm speed of 1000 rpm, a ground speed of 2.50 mph. The harvester
has a primary hex drive sprocket of 17 teeth, a primary web sprocket of 8 teeth and a web chain pitch of 50 mm for
the primary belted chain.
FIND:
Primary belted chain speed (mph).
SOLUTION:
PRIMARY BELTED CHAIN SPEED (MPH) = ((1000)(17)(8)(50mm)) = 3.30
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The primary belted chain speed is 2.75 (mph)
At this point the primary belted chain speed to ground speed ratio can be determined by simply dividing the primary
belted chain speed (which is 2.75 mph) by the ground speed (which in this case is 2.50 mph).
Primary belted chain
3.30
speed to ground
2.50
speed ratio =
1.32
3.23 EQUATION
