German Equatorial Mount Employing Optimized Offset Slider Crank Mechanism

Abstract

This article comments on the design of an actuator mechanism employed in a German equatorial mount for the purpose of establishing the right ascension rotation. The German equatorial mount is used for rotating an optical solar telescope. Both, the German equatorial mount and the telescope are being built at the Space Research and Technology Institute – Bulgarian Academy of Sciences.

The device is a variant of the offset slider crank mechanism having certain properties put as prerequisites aiming to satisfy specific needs of the equatorial mount. One such requirement is the angle of rotation being not less than 180 degrees. Another condition sought is to minimize the parameter of the device, namely the angle between the connecting rod and crank pin tangent. The latter minimization leads to lessening of forces exerted on the mechanism's parts.

After a short introduction of the subject and motivation, the article establishes the problem, then offers a solution. Finally, conclusions are drawn.