Driven Clutch Operation - Toro Workman MDX-D Service Manual

Driven Clutch Operation

The operation of the driven clutch is affected by trans-
axle load. When the vehicle is stopped, the drive belt is
held at the outer diameter of the driven clutch sheaves
from the pressure of the spring pushing the moveable
sheave against the fixed sheave and away from the
fixed cam.
Once the drive belt starts rotating, the driven clutch also
starts to rotate. With increasing speed of the drive clutch
on the engine, the drive belt begins to climb to the outer
diameter of the drive clutch sheaves. This increases the
tension on the drive belt and forces the moveable
sheave of the driven clutch to move away from the fixed
sheave against the pressure of the driven clutch spring.
As the belt tightens and the driven clutch sheaves open
up, the drive belt rides lower in the driven clutch
sheaves.
With increased load to the transaxle, the driven clutch
fixed cam resists forward movement relative to the
moveable sheave and drive belt. Torque from the drive
belt along with spring pressure moves the moveable
sheave up the ramp of the fixed cam. The drive belt be-
comes positioned closer to the outer diameter of the
driven clutch sheaves.
The fixed cam on the driven clutch moveable sheave ro-
tates on a pair of rollers in the fixed sheave base to allow
low friction movement of the moveable sheave (Fig. 3).
Drive Train
2
1. Moveable sheave
2. Fixed sheave
Page 4 - - 6
3
1
Figure 3
3. Spring
Workman MDX--D