HHN 31V • RIDE-ON POWER TROWEL — OPERATION & PARTS MANUAL — REV. #5 (03/02/07) — PAGE 23
How It Works (Figure 17)
Condition A:
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Engine Idling
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Drive Pulley: Small
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Driven Pulley: Large
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Belt: Loose and Stationary
Condition B:
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Engine Accelerating
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Drive Pulley: Small But Increasing
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Driven Pulley: Large But Decreasing
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Belt: Approaching Tightness
Condition C:
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Engine At High Speed
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Drive Pulley: Large
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Driven Pulley: Small
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Belt: Tight
Figure 17. Pulley Conditions
The torque sensitive pulley (Figure 18) utilizes a spring and cam
bracket. Peak performance results from proper interaction between
the driven pulley spring and the ramp angle of the cam bracket.
Figure 18. Pulley Spring and Cam Bracket
HHN -31V — MAINTENANCE
Blade Pitch
Matching Blade Pitch for Both Sets of Blades
Sometimes it may be necessary to match blade pitch between
the two sets of blades. There are some signs that this may be
necessary. For example, the differences in pitch could cause a
noticeable difference in finish quality between the two sets of
blades. Or, the difference in blade pitch could make the machine
difficult to control. This is due to the surface area in contact with
the concrete (the blade set with the greater contact area tends to
stick to the concrete more).
Single Pitch
™
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On a Single Pitch
™
trowel each spider assembly can be pitched
individually, forcing the operator to constantly make adjustments
on each pitch tower.
This clutch system provides a high pulley ratio (a low gear- so to
speak) to start out and a low pulley ratio ( a high gear- so to
speak) for a high speed operation, with infinite variation between
the two.
This means that it will not be necessary to give
full throttle
in
order to "break the blades/pans loose". The machine can slowly
be brought up to speed.
Clutch
