CEMB USA ER100 - Manual (Page 42)

42
use and maintenance manual Rev. 11-2011
ENGLISH
Tyre - 0.6 mm
Wheel + 0,3 mm
The eccentricity of the single elements is compensated.
The wheel is acceptable.
Example 3
Rim - 0 mm
Tyre + 1,2 mm
Wheel + 1.2 mm
The wheel eccentricity cannot be compensated by the rota-
tion because the rim is perfect!
SoLUtIoN: turn the tyre on the rim by 180°
rESULt: No improvement.
wheel
rim
tyre
rotation axis
wheel
rim
tyre
virtual wheel
rotation axis
wheel
rim
tyre
rotation axis
virtual wheel
virtual wheel
6.14.1 Runout
6.14.1.1 When and why TO USE MATCHING
The software associated with the eccentricity measure-
ment is a powerful tool to determine the need to perform
the relative rotation between the wheel and the rim in
order to reduce the eccentricity to within acceptable lim-
its. The criterion used is based on the fact that a rim with
acceptable tolerance, mounted with acceptable tyre, can
statistically generate an unacceptable total eccentricity
that can be improved by matching.
ER 100 is capable of automatically measuring the ec-
centricity of both the tyre and the rim from the inside.
The latter measurement generally corresponds to the rim
eccentricity in the tyre fitting area.
T
he RIm cAN be meAsuRed moRe AccuRATely usING The specIfIc
pRoGRAm WIThouT The TyRe
.
Example 1
Rim + 0.8 mm
Tyre + 0.6 mm
Wheel + 1.3 mm
The wheel eccentricityis excessive because an acceptable
rim or tyre has randomly been positioned in an “unfor-
tunate” position”.
SoLUtIoN: turn the tyre on the rim by 180°
rESULt: wheel eccentricity 0.3 – 0.4 mm (in tolerance)
Rim + 0.8 mm
Use of the wheel balancing machine