Ezgo 1600xd Repair Manual page 144

C
Drive pulley
D
Drive pulley
CVT operation under load (example: uphill road) - (C)
When the vehicle starts to drive uphill while driving on
the level road with maximum speed, without load, the
driven pulley attached to the drive shaft of the transmis-
sion has reaction not to turn. Then, as the belt rotates in
the direction shown in the figure (C) with an arrow, the
tension on the upper side of the belt is increased, affect-
ing the driving pulley. The exploded view of the driving
pulley is shown in the figure (E1). When the force of the
belt to move toward the center of the pulley by the belt
tension is increased from (F1) to (F2), the distance be-
tween the flanges of the pulley is increased and the ef-
fective diameter of the pulley is decreased from (R1) to
(R2). In this state, the force of the pulley flanges to move
toward each other by the centrifugal force (or spring
force) is increased from (F3) to (F4). As (F4) is balanced
with (F5), the horizontal force of (F2), the effective diam-
eter of the belt is not reduced any more, resulting in all
force in balance. On the other hand, the effective diam-
eter of the driven pulley is increased as the free length
of the belt is increased by reduction in the effective
diameter of the driving pulley. As a result, the more the
load increases, more the effective diameter of the driving
pulley decreases and the more the effective diameter of
the driven pulley increases, so this increases the reduc-
tion speed ratio, resulting in speed decrease and load
resistance increase.
4
-6
CVT - STRUCTURE AND OPERATING PRINCIPLE
Tension
Relaxation
Driven pulley
Relaxation
Tension
Driven pulley
E
F4
CVT operation under reverse load (example: downhill road) - (D)
When driving from an uphill to a downhill road, the load
applied to the wheels is changed then the transmission
and engine are driven by the wheels of vehicle. Then,
the driven pulley tries to rotate faster than the driving
pulley. Therefore, when the belt rotates in the direction
shown in the figure (D), the tension on the upper side
of the belt decreases and the tension on the lower side
of the belt increases. Then, as the lower side of the
belt with high tension moves toward the driven pulley,
the effective diameter of the driven pulley is decreased
as shown in the figure (E), so the effective diameter
of the driving pulley is increased by the free length of
the belt. As the effective diameter of the driving pulley
is increased and the effective diameter of the driven
pulley is decreased, this increases the speed ratio and
creates driving conditions suitable for a high-speed and
low-torque operation.
F2
F1
R1
F5
R2
F3
: Belt rotating direction
: Belt moving direction
UUVW317A
SUUV-W00 Apr. 2011