Secondary Clutch Operation - Toro Workman HDX Auto Service Manual

Secondary Clutch Operation

The operation of the secondary clutch (Fig. 6) is affected
by traction load. When the vehicle is stopped, the drive
belt is held at the outer diameter of the secondary clutch 1
sheaves from the pressure of the clutch spring pushing
the moveable sheave against the stationary sheave and
away from the fixed cam.
Once the drive belt starts rotating, the secondary clutch
also starts to rotate. With increasing speed of the prima-
ry clutch on the engine, the drive belt begins to climb to
the outer diameter of the primary clutch sheaves. This
increases the tension on the drive belt and forces the
moveable sheave of the secondary clutch to move away
from the stationary sheave against the pressure of the
secondary clutch spring. As the belt tightens and the
secondary clutch sheaves open up, the drive belt rides
lower in the secondary clutch sheaves.
2
With increased load to the transmission, the secondary
clutch fixed cam resists forward movement relative to
the moveable sheave and drive belt. Torque from the Figure 6
drive belt along with spring pressure moves the move-
1. Stationary sheave 2. Moveable sheave
able sheave up the ramp of the fixed cam. The drive belt
becomes positioned closer to the outer diameter of the
secondary clutch sheaves.
The fixed cam on the secondary clutch moveable
sheave rotates on a pair of rollers in the stationary
sheave base to allow low friction movement of the move-
able sheave.
Workman HDX Auto Page 4 − 7 Drive Train