Giving birth to bearing innovationsAsk a group of plant managers or engineers to describe their ideal bearing product and you’re likely to hear a common theme: Most want a bearing that is ideally matched to its operating environment and performs without failure for an extended lifetime. What turns that goal into reality – time and again, across many different applications – is innovation.
   In the bearing world, innovation is marked by the ability to continually improve bearing technology, design and manufacturing processes to benefit the widest group of end user organizations. At SKF, it is this model that has historically fueled the development of new and improved products designed to provide customers with a competitive advantage. In fact, SKF was founded through the innovative ways of a young maintenance engineer named Sven Wingquist.
   While working as a maintenance engineer at a Swedish textile plant in 1905, Wingquist was having a difficult time maximizing bearing life because the building was constantly shifting and settling. The ball bearings he was using were unable to accommodate misalignment and, as a result, they frequently needed to be replaced, causing frequent, expensive interruptions in work. And when replacement bearings were procured, they typically took weeks to arrive and offered no greater quality than the originals.
   Wingquist’s frustration led him to suggest to management that he design and manufacture his own bearings on site from Swedish steel. To his surprise, the company agreed and allowed him to use its facilities for the initial research, which he undertook in his “spare time.” The result of Wingquist’s pioneering ways was the first self-aligning ball bearing – a double row, ball bearing with a significantly longer life than its imported counterparts.
   From these humble beginnings and the desire to increase bearing life and improve bearing performance, the SKF organization was born.
A unique resource
Nearly 95 years later, SKF stands as the leader in bearing innovation – a tradition that has continually led to industry “firsts” that provide very tangible and significant benefits for customers. At SKF, innovation is a global effort, one involving the talents and skills of professionals in 130 countries on five continents. However, one central theme plays a key role in SKF’s ability to provide solutions: the unique facility known as the Engineering & Research Centre (ERC) in the Netherlands.
   Established in the early 1970s, ERC acts as the nucleus for all bearing technology and bearing manufacturing research undertaken by SKF worldwide. With a staff of over 160 scientists, engineers and support staff representing dozens of countries and disciplines, ERC offers an invaluable proving ground for new ideas that ultimately end up in real-world end user applications.
   “The ERC facility allows us to concentrate research in one high-powered center, and then to complement that research with extensive product development and testing at other SKF sites all across the globe,” explains Dan Snyder, director of engineering for SKF USA Inc.
   ERC’s highly skilled staff focuses its expertise in the areas that can most impact bearing quality and performance – including lubrication, tribology (the study of rolling motion), coatings, heat treatment, materials, mechatronics, and manufacturing trends. The center’s primary goal is to research and design improvements in three key areas: product development, manufacturing and process development, and application engineering.
   “Though focused in a central location, ERC doesn’t operate in a vacuum,” says Snyder. “All of ERC’s efforts originate with a customer need or issue identified in the field by SKF.”
   “Throughout the world, engineers in our Product Centers are continually taking the pulse of the industry and identifying new trends and issues in the marketplace,” he says. “They feed those trends and issues to ERC and ask our specialists to create appropriate solutions.” ERC also works one-on-one with major customers – including many automotive OEMs – that may have a specific need that can’t be addressed by SKF’s standard products as they exist today.
   “Offering one-on-one R&D support for major customers is a prime example of SKF’s philosophy to provide solutions, not just products,” Snyder says.
A whole new concept
Providing solutions has remained one of the key driving forces behind many of the bearing industry’s most significant new developments. One such development was CARB™ – the first new bearing to be introduced in the industry in over 50 years.
   The concept behind CARB originated with a particular problem in the paper industry. Extremely high temperatures used during the paper drying stage caused the bearing shaft to expand and become severely misaligned resulting in severe deflections. To combat this condition, customers in the paper industry needed a bearing that combined several important properties: a low section profile, high load capabilities, displacement capabilities, and the ability to withstand misalignment. No such bearing existed at the time.
   Enter the SKF ERC facility. Working closely with key companies in the paper industry, ERC researched the situation extensively and came up with a solution: the Toroidal bearing, a new bearing type that combines all four essential properties. This Toroidal bearing called CARB (Compact Aligning Roller Bearing), is the first new bearing the industry had seen in some 50 years – one that combines the best features of the spherical, cylindrical and needle roller bearings. These features allow CARB to provide end users with longer bearing life and increased radial capacity while reducing maintenance costs.
   Once CARB proved its tremendous value in the paper industry, SKF application engineers began to search for additional applications that could benefit from CARB’s unique properties. As the “voice of the customer,” these engineers made a commitment to identify other applications where CARB could provide valuable benefits.
Sensing a need
The introduction of sensor bearings to the marketplace also grew out of SKF’s response to another industry’s need. With the advent of the anti-lock braking system (ABS), the auto industry sought a wheel hub bearing that was “intelligent” enough to sense possible deflection or other variations in the assembly. Such a bearing would allow the ABS to identify a wheel that was turning faster (spinning) or slower (excessive resistance) than the others.
   In response to this need, SKF engineers worked closely with major OEMs to create the industry’s first sensor bearings. These “intelligent” components are able to detect variations in the positional ring of the bearing, by generating digital pulses at regular intervals. When fed to a control unit, these pulses help to provide information about the bearing’s angular position, the direction of rotation, and the speed or acceleration of the rotating shaft.
   “The sensor bearing acts as a ‘warning flag’ that can help spot problems before they become severe,” Snyder explains. With its use finding acceptance and success in the auto industry, SKF soon transferred the technology and its benefits to other applications, including electric motors and electronic steering systems.
Best of both worlds
Sometimes, finding the solution to a problem means looking at the facts from a different perspective – as was the case in the electric motor industry.
   When electric current passes through a bearing, component damage and premature bearing failure are inevitable. Both manufacturers and users of electric motors realized that the ability to keep electric current from passing from one ring of the bearing through the balls to the other ring could have a significant impact on motor life.
   Engineers at ERC studied the problem and proposed an innovative solution – a hybrid bearing that harnessed the advantages of ceramic material to extend bearing life. These hybrid bearings combine steel rings with silicon nitride balls,
a very hard inorganic material that is resistant to wear, is chemically inert in even the harshest environments, and is an electrical insulator. Through the addition of ceramic technology, the life of bearings used in electric motors can be increased as much as tenfold.
   “Ceramic is much harder than steel, and provides additional benefits in contaminated environment or in applications where there is insufficient lubrication,” Snyder says.

   “If a contaminant should find its way into the path of a ceramic ball, the ball can actually crush the contaminate.” For that reason, SKF hybrid bearings are used in pump applications, where traditional bearings have difficulty holding up under the harsh, corrosive, poor lubrication conditions. If an all-steel bearing were used in that same application, the contaminant might be embedded into the raceway on balls to start the spalling process. Besides its extended life, Snyder says the hybrid concept offers customers another important advantage – high speed. With most companies today attempting to run their processes ever faster, hybrid bearings offer a way to gain additional speed through the lower weight of the ceramic material as compared with steel. As a result, hybrid bearings are found in numerous high-speed applications – including many brands of in-line roller skates.
Longer bearing life
Sometimes, the innovations that lead to longer bearing life and greater reliability don’t involve a new breed of bearing at all. A prime example is SKF’s System 24, an automatic lubrication system that automatically supplies the right grease at the optimum interval. This “set it and forget it” approach allows end users to install a System 24 grease cannister directly on a bearing housing, and leave it for as long as one year in many applications.
   “System 24 eliminates the time and high labor costs associated with manual lubrication,” Snyder says. It was developed specifically for use with equipment that requires frequent lubrication – such as pumps and compressors – and for applications in hard-to-reach places. The innovative System 24 doesn’t just conveniently supply lubricant; it also prevents over-lubrication, a frequent cause of bearing failure.
   “Every innovation developed at SKF, regardless of the application, shares one feature in common,” Snyder notes. “They all focus on providing our customers a distinct competitive advantage within their respective industries. By helping organizations to reduce maintenance costs, minimize equipment failure and avoid unnecessary downtime, SKF innovations translate to strong weapons in today’s highly competitive marketplace.”