490
TECHNICAL INFORMATION
TECHNICAL
INFORMATION
WHEEL BALANCE
Most Norton grinding wheels are balance corrected
to a minimum of ISO Standards. Precision grinding
machines usually provide methods of accurately
balancing the complete wheel and flange assembly.
Modern production machines are now supplied
with automatic balancing systems, whereas, tool
room and older production machines still have to
be manually balanced, ensuring the best possible
grinding performance from the wheel.
The balancing procedure can be carried out either
on a special balancing stand or in-situ on the
machine. The machine manufacturer’s instructions
should be closely followed. There are many
methods of manually balancing the wheel assembly,
depending upon the number of balance weights in
the wheel arbour. A typical ‘two weight’ balancing
system technique is described below:
TWO WEIGHT SYSTEMS
•
Mount wheel between flange plates
•
Remove balance weights from annular groove on
mounting flange (can also be set diametrically
opposite if preferred – ensuring the weights cancel
each other out)
•
Dress periphery of wheel until running in
perfect truth
•
Remove complete wheel assembly from the
machine (after allowing sufficient time for the
coolant to spin out) & fix assembly onto the
balancing mandrel
•
Place on balancing unit & allow to turn freely.
When stationary, mark top centre (light spot)
with chalk
•
Re-position the balance weights so that the
bottom side face of each weight, that is furthest
from the light spot, forms a right angle i.e. 90°.
See illustration 1A
•
Turn wheel assembly so that one balance weight is
approximately 45 degrees from the horizontal line
& release the wheel. Note the direction in which
wheel rotates, the weight may revolve upwards
towards the vertical line. In this instance the
weight should be moved down away from the light
spot (always adjust the weights in the opposite
direction of rotation) to begin bringing the wheel
into balance. See illustration 1B
•
Continue checking the weights, alternating
between the left & right hand balance weights in
turn. Repeat until the wheel remains stationary
in all positions. Move the weights a maximum of
3mm at a time, reducing this amount as the wheel
rotates slower. See illustration 1C
•
Continue until assembly remains static in all
positions. Lock balancing weights in position &
remount assembly onto the machine spindle
•
Important: – Ensure the balancing ways (knife
edges or rollers) on the balancing stand are level
in all directions. Care must be taken to initially find
the true light spot of the wheel
FIG 1A
FIG 1B
FIG 1C
VERTICAL
LINE
VERTICAL
LINE
VERTICAL
LINE
LIGHT SPOT
LIGHT SPOT
LIGHT SPOT
BALANCE
WEIGHT
BALANCE
WEIGHT
BALANCE
WEIGHT
1...,480,481,482,483,484,485,486,487,488,489 491,492,493,494,495,496,497,498,499,500,...505