One of the largest components manufactured
by Schaeffler last year was a double-row tapered
roller bearing featuring an outer diameter
measuring 3.6 meters and a weight just
over nine tons. This bearing is used to support the
main shaft in an offshore wind turbine. Although this
bearing is currently used in overseas markets, it is expected
to be installed in North America-based applications
later this decade.

Wind turbines equipped with bearings
of this size certainly present some interesting
challenges for application engineers
and designers, according to Anant
Bhat, business unit manager—railway
and renewable energy, Schaeffler Group USA Inc.

“It is important to meet or even exceed several critical requirements
such as contact pressure, rating life, safety factor
as well as the actual reliability of the bearing and its components.
This is where Schaeffler’s specially designed in-house
calculation and simulation tools are invaluable: they assist
our engineering and design team with the ability to provide
comprehensive analysis support to help ensure optimum
bearing design.”

Bhat said that Schaeffler’s production team can rely on
several key manufacturing competencies including forging,
soft machining, specially designed heat treatment, hard machining
and final assembly for components like this.
As a final manufacturing step, Schaeffler undertakes some
of the industry’s most stringent quality inspections and measurements
of the finished bearing that enable the company
to ensure the highest quality and reliability for its customers
throughout the world.

“In-house design validation and testing was performed on
Schaeffler’s proprietary ASTRAIOS test stand, one of the largest,
most modern and highest performing bearing test rigs
in existence,” Bhat said. “ASTRAIOS simulates the real loads
and moments that occur in a wind turbine, which enables
Schaeffler to make a major contribution toward reducing development
times for wind turbines. In doing so, ASTRAIOS
facilitates a more reliable design process while also increasing
the cost-effectiveness and safety of these massive powergenerating
machines.”
Along with projects in other industrial sectors, Schaeffler
is currently working on additional bearings of similar size for
main shaft applications in offshore wind turbines. In recent
years, the company has gained a great deal of experience
producing large components.

“In 2016, Schaeffler introduced the world’s first sealed ultralarge
241/1250 spherical roller bearing, which was specifically
designed for the highest-capacity High Pressure Grinding Roll
Crushers (HPGRs) used by the mining industry. The seal inside
this massive roll support bearing is designed to prevent
the crushing materials from contaminating its internal components,”
Bhat said.

In 2019, Schaeffler produced the largest spherical plain
bearing in the company’s history (to date). “Featuring an
outside diameter of 1.9 meters, a bore diameter of 1.5 meters
and a height of 60 centimeters, this special bearing weighs
approximately 4.7 tons. It will be installed in a cutter suction
dredger that is used in offshore oil & gas drilling applications,”
Bhat added.

With each new bearing application, Schaeffler’s engineering
and design team gains valuable experience and the tools
necessary to provide reliable products for the areas like wind,
mining and oil & gas no matter the size or scope.