Background

SKF Limited is a world leading supplier of a range of parts and components for the aerospace industry, including supplying Original Equipment Manufacturers (OEM) and Maintenance Repair Overhaul (MRO) companies. The aerospace industry requires sub-components to be made with a high level of precision, meaning quality control during manufacturing is of the utmost importance.

Challenge

The parameters of the bearing assembly process are determined by assuming nominal dimensions of all the subcomponents. However, small variations in the dimensions of each subcomponent can result in a mismatch in the assembled subcomponent sizes, which causes inconsistent product performance and requires rework to correct. This causes a significant cost increase and prevents SKF from entering the higher volume/lower cost markets.

Solution

To address this, SKF worked with the Automation Systems Group (ASG) at WMG, University of Warwick to develop a high-accuracy, non-contact in process measurement system which allows SKF to use the dimension information collected to dynamically customise the downstream assembly process. This allows SKF to work towards a ‘right first time’ manufacturing methodology, reducing rework costs, and assists in the adoption of automated quality control/inspection functions that are currently completed manually.

This solution utilised a static 3D stereoscopic camera to measure the dimensions of each component while it is rotated on a bespoke platform. This had major benefits over other solutions such as rotary laser line scanners, including lower cost, lower computational power required, and better metrology data produced. The only disadvantage was the greater automation burden to rotate the component to measure all sides.

Initially a proof of concept was developed, which was trialled using representative SKF parts. This was then put through a qualification test to compare this new system with traditional techniques and the results found that the new automated system was faster with similar accuracy compared to traditional measurement methods

The project delivered an integrated system for fast, non-contact metrology measurements for a broad range of product sizes without manual intervention, suitable for a variety of quality and in-process measurement purposes. The project also delivered the software tools and know-how to enable additional systems for similar inspection regimes.

Impact

The system developed by ASG is the first of its type to be engaged within SKF Aerospace (Global) and has demonstrated what can be achieved in automation for SKF. SKF Aerospace have previously not had in-line real time measurements of parts and they did not have the skills, equipment, or resource to introduce this type of activity without the assistance of WMG. Collaborating with WMG provided SKF with access to WMG’s state-of-the-art facilities, experienced experts, and future grant opportunities. Without the contribution of WMG, SKF would either have not explored this automation route or would have pursued it commercially with a higher cost and risk involved.

In summary, this new system will have the following effect on SKFs bearing assembly line:

• Increased quality
• Increased productivity
• Reduced rework
• Reduced material consumption
• Reduced cost

And for the company as a whole, this project has contributed to:

• Increased know-how and understanding of automated inspection systems
• A right first time manufacturing methodology
• The ability to identify other opportunities to improve their processes with automated in-line inspection in other areas of their business

“This technology is a first in SKF Aerospace, the demonstration of what could be achieved with similar technology elsewhere, especially when combined with automation. It will set a remarkable precedent and will be looking at similar technology and know-how to improve quality and productivity elsewhere.” Neil Tolson, Business Controller, SKF.

Adam Walton, Lead Engineer, WMG, added, “Automation Systems Group at WMG, University of Warwick, has a range of capabilities to support the automation of practices just like this one. SKF have been able to use this technology to save time and cost, improving their production without reducing their workforce.”

For more information about this project or working with us, please email wmgbusiness@warwick.ac.uk