Run-Out-Tester (ROT)

The mechanical layout is similar to conventional wheel measuring machines with measuring rollers. In contrast to these machines, laser triangulation sensors are used to project a laser line on the rim and to scan it.

Two laser sensors are used to measure the values on both sides of the rim, see Fig or the 3D Animation. Both lasers are moved with 3 linear axes to the measuring position. These positions are set in the test plan.

The following values are measured, see the LINK to the fig. (Measured Values):

• Lateral and radial run-out based on a measuring ball (1)
  By use of a virtual measuring ball which fits tangential to the rim flange and the rim bead seat, the X and Y positions of the ball’s center are determined via suitable sensors. The measuring principle behind the measuring ball means that the measurements of lateral and radial run-out are always correlated. This follows from the fact that a change in the roller’s horizontal direction always induces a change in the roller’s vertical direction. 

• Independent lateral and radial run-out (2a, 2b)
  The lateral and radial run-out are also measured at fixed points on the profile in accordance with DIN 7818. This serves to eliminate the correlation between radial and lateral run-out measurements. At position 2a, the radial run-out is measured in the radial direction (Y), and at position 2b the lateral run-out in the lateral (X).
  

• Harmonic analysis of radial and lateral run-out
  The software performs a harmonic analysis that yields the amplitudes of the first ten harmonics.
  

• Circumference of the rim (1)
  This measuring data is calculated from the position of the measuring ball (1) and the encoder values for the angle of rotation. The calculation rules are based on standards/guidelines (DIN 7839).

• Offset (2b)
  The offset is calculated from the measurements at positions 2b on both sides of the rim.
  

• Rim width (2b)
  The rim width is also calculated from the measurements at the measuring positions 2b on both sides of the rim.
  

• Flange/hump position, 2-dimensional (3a, 4)
  The flange and hump position are determined in 2-dimensional, i.e. in the radial and lateral direction. Then the hump height is calculated from the rim’s center axis.
  

• Flange height (2a, 5, 3a/b)
  The flange height is calculated from the flange position and the rim shoulder in accordance with DIN 7817/7818.
  

• Angle of inclination of rim shoulder (5)
  The rim angle between the flange and the hump can now be determined.
  

• Valve position (6)
  Determination of the angular position of the valve or valve hole.
  

• Determination of matching point
  Different calculation methods are available (e.g. sum vector of first harmonic of radial runouts).

• DIN 5401 – Wälzlager – Kugeln für Wälzlager und allgemeinen Industriebedarf
• DIN 7817-1 – KFZ-Felgen mit Hornform J, JK und K
• DIN 7817-2 – KFZ-Felgen mit Hornform J, JK und K – Hump-Ausführung
• DIN 7817-3 – KFZ-Felgen – Hump-Sonder-Ausführung
• DIN 7818 – KFZ-Tiefbettfelgen – Hornformen C, D, E und F
• DIN 7838-1 – Felgenmessbänder für Felgen mit beidseitig festen Schrägschultern
• DIN 7838-2 – Felgenmessbänder für Felgen in Hump-Ausführung
• DIN 7839 – Felgenumfangslehren – Kugellehren und Scheibenlehren
• DIN 7831 – Felgenprofillehren für Tiefbettfelgen nach DIN 7817-1 + DIN 7818
• DIN 70020-5 – Kraftfahrzeugbau – Reifen und Räder, Begriffe und Messbedingungen
•  ETRTO – European Tyre and Rim Technical Organisation – Standards Manual – Chapter R