14-17
4170-09
If weight is not equally distributed around the wheel, unbalance centrifugal force by the wheel rotation
produces vibration. As the centrifugal force is produced proportional to the square of the rotating speed,
the wheel weight should be balanced even at high speed. There are two types of the tire and wheel
balancing: static and dynamic. Abnormal vibration may also occur due to unbalanced rigidity or size of
tires.
Static Balance
â–¶
When the free rotation of the wheel is allowed,
the heavier part is stopped on the bottom if the
wheel weight is unbalanced and this is called
"Static Unbalance". Also, the state at which tire's
stop position is not same is called "Static
Balance" when the wheel is rotated again. If the
part A is heavier as shown in the figure 1, add
the balance weight of a weight corresponding to
unbalanced weight from B to A to maintain the
static balance. If the static balance is not
maintained, tramping, up and down vibration of
the wheels, occurs.
Dynamic Balance
â–¶
The static unbalance of the wheel creates the
vibration in the vertical direction, but the dynamic
unbalance creates the vibration in the lateral
direction. As shown in the figure 2 (a), if two
parts, (2) and (3), are heavier when the wheels
are under the static balance condition, dynamic
unbalance is created, resulting in shimmy, left
and right vibration of the wheels, and the torque
Fxa is applied in the axial direction. To correct
the dynamic unbalance, add the balance weight
of a same weight for two points of the
circumference of the rim, A and B, as shown in
the figure 2 (b), and apply the torque in the
opposite direction to the torque Fxa to offset in
order to ensure smooth rotation of the wheel.
Center
A
B
(a) (b)
[Figure 1]
[Figure 2]
3. WHEEL BALANCE
To Next Page
Loading...
Need help?
General
