Str46spvgh — maintenance, Ab c – Multiquip STR46SPVGH User Manual
Page 29
STR46SPVGH • RIDE-ON POWER TROWEL — OPERATION MANUAL — REV. #0 (07/17/08) — PAGE 29
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STR46SPVGH — MAINTENANCE
The "Variable Pitch Pulleys" have one
fixed face
, and one
moveable
face
. The
drive
pulley ( torque converter, Figure 25) moveable face
is controlled by roller weight arms and springs, which change
position according to engine speed. The
driven
pulley
moveable
face
is controlled by a spring and belt tension.
Figure 25. Variable Pitch Pulley
Figure 24. Pulley Interaction
As shown in Figure 23, centrifugal force pushes the roller arms (see
Figure 24 below) against the ramp plate, forcing moveable face
toward fixed face squeezing belt.
Figure 26. Pulley Conditions
How It Works (Figure 26)
Condition A:
z
z
z
z
z
Engine Idling
z
z
z
z
z
Drive Pulley: Small
z
z
z
z
z
Driven Pulley: Large
z
z
z
z
z
Belt: Loose and Stationary
Condition B:
z
z
z
z
z
Engine Accelerating
z
z
z
z
z
Drive Pulley: Small But Increasing
z
z
z
z
z
Driven Pulley: Large But Decreasing
z
z
z
z
z
Belt: Approaching Tightness
Condition C:
z
z
z
z
z
Engine At High Speed
z
z
z
z
z
Drive Pulley: Large
z
z
z
z
z
Driven Pulley: Small
z
z
z
z
z
Belt: Tight
1
Drive Pulley
2
Driven Pulley
3
Low Engine RPM
4
Low Output Speed
5
High Engine RPM
6
High Output Speed
7
Moveable Face
(Controlled by a Spring and Belt Tension)
8
Moveable Face
(Controlled by Roller Weight Arms and Springs)
9
Distance Moveable Face Travels
10
Centrifugal Force
1
Drive Pulley
2
Ramp Plate
3
Weight
4
Roller Arm
5
Spring
6
Bushing
A
B
C
1
2
3
4
5
1
Drive Pulley
2
Driven Pulley
3
Neutral
4
Low Speed
5
High Speed