Traction Drive Systems; Introduction - Toro Lawn-BoySeries Service Manual

INTRODUCTION

All models use some variation of a friction drive. The
engine drives a belt, which causes a drive plate(s) to
rotate. As this belt is constantly tensioned, the belt and
drive plate turn whenever the engine is running
(Figure 67).
Figure 67
Clutching and speed control is accomplished by
moving the friction wheel. When declutched the friction
wheel is not contacting the drive plate (Figure 68).
When the drive is engaged, the friction wheel is moved
into contact with the right side of the drive plate (Figure
69). As the friction wheel begins to turn, it drives gears,
or sprockets and chains, which provide the speed
reduction for the axle. Ground speed is determined by
the point on the drive plate where the friction wheel
makes contact. The further from center, the faster the
friction wheel will turn. Moving the friction wheel to the
left side of the plate changes direction of rotation
(Figure 70).
Two Stage Snowthrower Drive Systems Manual
Chapter 3 — Traction Drive Systems
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Figure 68
1. Gap
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Figure 69
1. Forward
Figure 70
1. Reverse
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