Page Areas:

Current Submenu:

Position Indication:


Development of a measurement system for high precision measuring diameter-unsteadiness

Rene Hell

In cooperation with the department Quality Technology Centre (QTC) of the company SKF Austria AG, a manufacturer of roller bearings, a system for precisely measuring the non-uniformity of the diameters of bearing parts is developed.

The deviation of the actual shape of a bearing-component from an ideal circle affects the assembled bearing negatively. The individual parts are gauged seperately, whereby variations, that are out of tolerance, are detected in an early stage and can be discarded.

An appropriate measurement electronics to accurately measure voltages using a Blackfin-type digital signal processor is developed and its performance determined. Moreover an algorithm for the digital processing of the measurement signal is implemented and its capabilities determined.

Subsequently a PCB for evaluating the output of the sensor is developed (see Figure 1).

Figure 1: PCB for evaluating the output of the sensor

Figure 1: PCB for evaluating the output of the sensor

The operating voltage for the system is supplied by an auxiliary device. A linear-variable differential inductor is used as sensor. The sensor output-voltage is converted analogue-to-digital, processed digitally and sent to a Host-PC via USB. The program of the processor is designed in such a way as to enable the integration of the measurement system into the proprietary measurement software used by SKF.

Figure 2: Measurement of a ceramic-ball

Figure 2: Measurement of a ceramic-ball

The completed measuring system is used for some measurements for testing purposes and its accuracy is determined. In Figure 2 the polar diagram of the measurement of a ceramic-ball is displayed.

The circulation of the project work is restricted from June 30, 2008 for a period of 5 years.

June 30, 2008