Laser interferometer arrangement for measuring the axial play of two parts mounted so as to be capable of mutual rotation

摘要

The invention relates to a laser interferometer arrangement for measuring the axial play of two parts mounted so as to be capable of mutual rotation. In order to be able to carry out such measurements of axial play even on wheels or wheel hubs having stationary wheel journals (trunnions), different avenues to this solution are proposed for this special application. One avenue provides a miniature laser head co-rotating with the hub and fitted with laser diodes. Signals are transmitted via slipring transformers to a signal-evaluating device set up at a fixed location. In the case of a laser head set up at a fixed location and of a rotating polarisation beam splitter, it is necessary to use circularly polarised light in the transmission section between these two components, it being the case that this light is converted back into linearly polarised light inside the measurement and reference section by means of a polarisation transducer plate co-rotating with the polarisation beam splitter. Various possibilities for configuring such an interferometer arrangement are described. Furthermore, it is also possible to mount the polarisation beam splitter in a fixed fashion but on the inside, and to hold the rotating measurement reflector on the hub by means of a partially transparent bell. Various possibilities of configuration are described for this purpose as well.