Bearing R&D: a critical process

Oct 3, 2012 | Electrical & electronics

Small components such as bearings and tolerance rings are integral to successful product development, but ensuring that these perform under adverse conditions and contribute to the overall product benefits requires R&D investment. Janaki Weiden, global marketing manager for the Saint-Gobain Performance Plastics’ Bearings & Tolerance Rings Group, comments

Bearings are used to maintain separation and reduce friction between two moving parts. Although a seemingly tiny part, the technology behind these has advanced to reduce friction and noise through special finishes and enhance sustainability by eliminating heavy metals – all thanks to R&D.

At its most basic level, a bearing provides the interface between a rounded shaft and the housing in which it rotates. Though often constructed from steel and aluminium, bearings are increasingly designed according to the application and can include various coatings for weather-proofing, heat protection and wear-resistance.

Over time, R&D has enabled the incorporation of polytetraflouroethylene (PTFE) compounds which feature the lowest coefficient of friction of all solid materials. The addition of proprietary PTFE compounds, for example, results in smoother movements and higher wear resistance. These properties are essential in bearings used in a wide range of products, including those in the appliance, automotive, bicycle and solar industries.

In solar applications, bearings are used in the construction of the parabolic troughs found in Concentrated Solar Power (CSP) plants. Parabolic trough collectors represent the most advanced technology for collecting and converting sunlight into electricity. Bearings are applied at the pivot points of tracking systems on these. The troughs track the sun over the course of the day to collect light which is later transferred to heat, then to electricity. Friction at the pivot points can impair the accuracy and efficiency of the troughs.

Looking to reduce friction levels in the motion of these troughs, Saint-Gobain R&D led to the launch of its SOLGLIDE T and SOLGLIDE M families of bearings. These are designed with a fluropolymer to be non-corrosive, self-lubricating and 100% weatherproof. These can also withstand extreme temperatures, are durable and provide 50% less friction than comparable models thanks to the addition of proprietary PTFE based compounds. Over time, this reduction in friction helps to maintain the accuracy of the troughs 4in tracking the sun, optimising energy output.

Tolerance rings also significantly affect larger devices. A tolerance ring is essentially a flexible shim that fastens two cylindrical parts. With a strong dose of R&D, however, tolerance rings made from high-quality steel that are radially sprung become engineered fasteners that not only optimise the join between mating components, but reduce friction and noise.

From refrigerators to vacuums, low output electric motors drive the appliances that we use every day. These  low output, or fractional horsepower, motors (FHPs) are capable of creating excessive noise, vibration and harshness (NVH). R&D allowed a component as small as a tolerance ring to significantly reduce noise and vibration in a household appliance.

In FHP motors, press fit and adhesive solutions are the most commonly found bearing mounts. While press fits literally press the mating components together to create friction, adhesive solutions use unstable solvents to achieve the same join. Press fits rely on rigidity to fasten the bearing, while adhesive solutions depend on unstable chemical bonds, both of which can result in noise and vibration.

Through rigorous application testing, Saint-Gobain’s researchers worked to optimise its RENCOL tolerance rings for FHP motor applications. Because they lack rigidity but provide a firm hold, the tolerance rings affect both transmissibility and structure modification – two of the major ways to reduce noise and vibration. The spring-like qualities of the ring, and the ability to perfect the thickness of material and geometry, allow manufacturers to alter the stiffness of the bearing mount to realise their optimum transmissibility ratio. Fine-tuning in this way enables manufacturers to decrease the ratio of vibration output to input in the system. Only through this rigorous application testing were researchers able to overcome this major challenge with an everyday household item.

R&D partnerships

Partnering with component providers that offer extensive R&D capabilities can help manufacturers develop a better product faster and with greater efficiency. Saint-Gobain utilised this approach in working with Cane Creek Cycling Components to achieve what is said to be the world’s lightest headset. Headsets provide a rotatable interface between the bicycle fork and the frame. Bearings, most commonly rolling element bearings, are applied between these two moving parts to decrease friction, increase performance and reduce the energy output of the cyclist. But, traditional bearings were too heavy for the lightweight bicycle desired.

So, Saint-Gobain’s team worked closely with Cane Creek to develop the NORGLIDE X2, a new version of its existing NORGLIDE bearing, which is said to be less than one-fourth of the weight of alternatives on the market. The companies worked closely to create the X2 material at the Willich, Germany, R&D facility belonging to Saint-Gobain before measuring the appropriate quantities of the material for the application and finalising the bearing design with the business unit’s team in Wayne, New Jersey.

The step-by-step R&D collaboration resulted in Cane Creek’s first generation AER family of superlight headsets – each approximately half the average weight of comparable products on the market. The most recent generation of the AER headsets utilises NORGLIDE T bearings which offer greater rigidity.

Attention to detail

A good R&D partner must possess the ability to test and troubleshoot challenges at various stages of component development alongside the product manufacturer, through to implementation. Attention to detail is rigorous but necessary to produce the most effective components for a given application.

But, manufacturers from the automotive, appliance, bicycle and solar markets don’t have to go it alone – by pairing with component suppliers that offer extensive R&D capabilities and support collaborative application testing, they can find or help create solutions to enhance product performance and build brand equity.



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