Ball bearing completeness inspection
In a manually loaded assembly line for production of high quality ball bearings in small batch sizes, the presence of all balls needs to be ensured. The key requirement is that bearings with diameters from 40mm to 280mm and with exceptionally small gaps between the inner and outer ring have to be inspected. The use of ceramic balls means that reflected light inspection is not possible due to the lack of reflection. The inspection unit is to be integrated into the line after completion of the bearings but before packaging.
The system concept calls for special solutions in terms of the optics and the transportation of parts. The narrow gap means that detection using transmitted light is only possible with a telecentric lens. For part diameters of around 300mm, the design of this kind of lens means that it is best used in conjunction with a line scan camera. In addition, the parts cannot make any erratic movements during transportation under the line scan camera, as this would mean that the small gaps could not be detected or pseudo faults would be recorded. Therefore, web belts with seams cannot be used – a roller conveyer with small roller spacing needs to be designed. The wide variety of versions can be inspected easily by adjusting the parameters for the hole sizes to the size of the bearing. This enables the system to be operated and adjusted by personnel without prior experience after brief instruction.
The robust construction and easy operation mean that fault detection is extremely reliable, ensuring acceptance among the system operators. This inspection system guarantees that completely assembled high quality special bearings are delivered.