Device for optical alignment measurement between two variously rotatable shafts

摘要

The invention relates to a device for optical alignment measurement between two rotatable shafts. Mounted on the end of one shaft is a measuring head which transmits coaxially with the rotation axis a primary beam in the form of a linearly polarised laser beam. Firmly mounted on the end of the other shaft, which is arranged at an axial spacing, is a roof-edge reflector whose ridge is perpendicular to the axis and extends through the rotation axis of this shaft. The secondary beam retroreflected by this roof-edge reflector is situated coaxially with the primary beam. A polarisation beam splitter can be used to separate the primary and secondary beams from one another. By determining the beam position in an area-resolving fashion, it is possible to determine a beam position signal which is relevant to the angle error and relevant to the error in alignment. When this measurement is repeated on a plurality of circumferential positions of the two shafts in conjunction with an identical mutual circumferential position, the alignment position can be determined with regard to parallelism and to coaxiality. Because of the central arrangement of the primary and secondary beams, the alignment measuring device is largely independent of aberration tolerances in the case of an identical position of the angle of rotation of the two shafts relative to one another. Thanks to determining the beam position with regard to parallelism in accordance with the autocollimation principle, the dependence of the alignment measurement on the axial spacing of the two shafts is also eliminated. In order not to suffer any light losses during beam splitting, ... Original abstract incomplete.