Drive Clutch Operation - Toro Workman MDX-D Service Manual

Drive Clutch Operation

The operation of the drive clutch is affected by engine
shaft speed. With the engine not turning, the CVT drive
belt rests low within the drive clutch sheaves as the pres-
sure of the spring holds the sheaves apart. As the en-
gine increases in speed, the clutch weights attached to
the moveable sheave move outward as they spin about
the engine driveshaft. The outward movement of the
clutch weights presses against the rollers and overcom-
es spring pressure through the spider assembly, which
forces the moveable sheave closer to the fixed sheave.
This inward movement of the sheave engages the drive
belt to drive the driven clutch.
With increasing engine speed, the moveable sheave
continues to move inward, which forces the drive belt to
ride towards the outer diameter of the clutch sheaves.
When engine speed is decreased, the clutch weights
exert less force on the rollers and thus the spring. The
spring pressure overcomes the force of the clutch
weights and shifts the moveable sheave away from the
fixed sheave. The drive belt disengages from the clutch
sheaves at a point where the force of the spring is great-
er than that of the clutch weights.
Workman MDX--D
1
1. Fixed sheave
2. Moveable sheave
3. Spider assembly
4. Cover
Page 4 - - 5
3
2
4
7
6
5
Figure 2
5. Clutch weight (3 used)
6. Roller (3 used)
7. Spring
Drive Train