Compact rotary table bearing for 360° shots in camera technology

In product photography, turntables are used to take fully or semi-automatic photos of products from all sides.
However, the turntable realised in this application can also present products that do not have flat surfaces or are very narrow (such as inline skates or smartphones). The product is fixed in place thanks to another turntable above it. A pivot bearing is also used for this, which moves in synchronisation with the turntable below. The upper turntable can also be adjusted in height so that products of different heights can be fixed between the two plates.
This adjustment is made by means of two electric lifting columns in the front area of the turntable. The rear area, on the other hand, should be kept free in order to minimise the time required for post-processing the images. As the two columns cannot carry much weight, the rotary unit attached to them should be as light as possible.
In addition, the objects are often mounted off-centre, especially when shooting for a second rotary axis, which leads to an asymmetrical load on the bearing. This load situation is difficult to manage with simple plain bearings. For the bearing and drive of the rotary discs, a solution was sought that was as light and compact as possible and required only a few components. A high mechanical load capacity and low speed were also required.

The iglidur ® slewing ring bearing PRT-01-60-TO-HTD8M with outer drive ring made of aluminium meets the requirements of the application in particular. Compared to conventional solutions with rolling bearings, it is significantly lighter and less expensive, but at the same time offers sufficiently high load capacities in all directions. The integrated external gearing also enables a direct drive via a stepper motor with gearbox. As an additional reduction ratio (i=3) was realised via the ratio of the outer circumference of the bearing to the outer circumference of the drive wheel, the motor could be dimensioned correspondingly smaller, which further reduces costs and weight. The vibration-damping specification of the slewing ring bearings also has a positive effect. In conjunction with the toothed belt, any vibrations that could be excited by the stepper motor are effectively suppressed. The drive generates a smooth, even rotary movement without causing the sheet metal parts used for the housing to vibrate. The sliding elements of the PRT slewing ring bearing are made of the maintenance-free material iglidur® J, which runs completely lubrication-free. The function of the slewing ring bearing is thus ensured in the long term and even under high loads.