The automotive industry is shifting for
everyone, bearings manufacturers
included. Here’s what you need to know
to make sure you’re shifting with it.

    The automotive industry has
been prepping for a big shift
for years now: the shift to
electric transmissions. I doubt
anyone’s a stranger to the discussion
surrounding the direction the industry’s
heading — after all, it’s had a
perpetual place in the industry-wide
discourse for years at this point. And
during that time, the jump to electricbased
transmissions has morphed
from a conversation about “if” the industry
would shift to a conversation
about “when.”

    But along with the increased certainty
of that conversation, there’s
one more important thing to talk
about: how to shift with it. In Power
Transmission Engineering, as well as
our sister magazine, Gear Technology,
we’ve already talked at length on
numerous occasions about how this
is going to affect gear manufacturing,
most notably by drastically reducing
the number of speeds, and therefore
gears, needed per transmission. But
the ever-mounting market pressure
to switch to electrified powertrains is
going to affect far more than just that.Gears may be ground zero for this particular
shift in the industry landscape,
but that doesn’t mean that other fields
shouldn’t be paying attention, as well,
and preparing to adjust accordingly.

    “These changes will have an impact
on the bearing industry as well,” Jitesh
Modi, engineering director of transmission
applications at Schaeffler, said. “The current 8/9/10 speed
planetary automatic
transmissions involve a
large quantity of drawn
and stamped bearing
products like radial and
thrust needle bearings. The
drive units for electric vehicles
mainly involve precision
ground ball and roller bearings.
The main performance
requirements for these bearings
are higher speeds, lower friction
and NVH, improved power density
and increased efficiency.”

    So what are people working
with bearings going to need to
know to meet those shifting industry
demands? Well, we sat down with
Schaeffler to talk about what skills you
might want to brush up on to make
sure you’re ready to not just survive,
but thrive in this changing market.

    First, let’s talk about the shift itself.
Ball and roller bearings are far from
unknown in the automotive market.
They’re currently seeing use primarily
as main shaft and gear support bearings
in more conventional transmissions, but according to Modi, they’re
going to be rising to increased prominence
and taking center stage along
with electrified transmissions. And
along with that comes a few extra
design considerations bearing manufacturers
will have to think around.

     “Their application in electric vehicles,
especially in electric motors,certainly requires design optimization
and precision manufacturing to provide
necessary running accuracy and
desired performance at high speeds
to an extent of 20,000 rpm and even
above in the near future,” Modi said.
“In addition, creep damage and electric
current passage through bearings
can pose additional challenges in electrified
powertrains.”

    As an example, Modi pointed to how
the higher speeds in electric motors
lead to an entire host of considerations
that require manufacturers to focus on
the bearing cage design.
“The cage geometry, pocket clearance,
cage guidance and its overall
strength play an important role in
bearing performance,”

    Modi said. “For
sealed bearings, the sealing design can
influence bearing limiting speeds due to friction and heat generation. The
seal wear can lead to grease leakage
and subsequent bearing failures. The
compatibility between sealing material
and grease becomes a key consideration
as well.”

    While none of these factors are necessarily
“new” considerations when
designing a bearing, they’ll all require
some reconsideration for electric transmission
applications. Those higher
speeds that electric motors run at will
require sturdier, higher quality bearings
alongside them. Much like it is for
the gearing market, electrified transmissions
will make increased quality
demands of bearing manufacturers,
and cage design is a primary method
Modi pointed to meet those demands.

    Bearing designers and manufacturers
aren’t the only ones that are going
to need to adjust to how the industry’s
shifting. There will be a whole host
of fresh demands placed on maintenance
professionals and the aftermarket,
as well, mostly in the form of new
kinds of damage you might not be used
to in bearings used in conventional
transmissions.

    On the maintenance side of the bearing
market, however, Modi’s advice is
pretty straightforward.

    
“Overall knowledge and understanding
of typical bearing failures in
electrified powertrains will be important
for the maintenance professionals,”
Modi said. “Familiarity with bearing
diagnostic tools and techniques
can be really helpful for efficient
troubleshooting.”

    The advice more or less amounts to
“keep doing what you’re doing,” except
in a slightly different field. But while
the core competencies to get the job
done might be the same, that doesn’t
mean that maintenance professionals
won’t have to learn something
new. Much like with bearing design,
the increased speeds and electrical
currents running through these new
powertrains can cause all manner of
issues that you’ll need to brush up on.
The electric current itself can induce
craters or fluting damage in a bearing,
and then, of course, there’s the already
mentioned increased strain placed on
the bearing cage due to the motor’s increased speed to worry about.

    “The higher speeds of electric motors
can lead to bearing cage failures if it
is not designed suitably for the given
speeds,” Modi said. “If electric motor
bearings operate at high speeds with
very low loads, bearing failures can
result from skidding or slippage damage
and also lead to NVH issues.”

    Naturally, these are all issues a
maintenance shop will be called on
to handle. Some of these failure states aren’t usually present in conventional
transmissions, but as electrified
transmissions work towards becoming
the norm, those unique problems
will become more and more common
thorns in the industry’s side — perhaps
all the more so during the technology’s
early years if manufacturers take a bit
to get the cage design right.

    
Modi also pointed to a list of skills
and knowledge sets that will be important
for keeping competitive in the maintenance market in the future,
citing “knowledge regarding bearing
condition monitoring using vibration
analysis, preload adjustment, seal
wear and grease leakage, evaluation
of mating parts and bearing damage
analysis.”

    For everyone involved, however,
there are a few other non-bearing matters
you might want to brush up on
while you’re at it. Most obvious, make sure you understand how electric
motors function, why they function
the way they do, and their different
industrial applications.

    Sure, you might not make motors
personally, but like with everything
else in manufacturing, a bearing is only
a single component of a much larger
system, and how it fits into that larger
system is important. Understanding
the other components that bearing’s
going to have to play with can go a long way towards helping
design a quality part that
will last for years — or,
if the worst comes to
happen and a part
fails, understand
what went wrong
and why.

    
For other supplemental
skills, Modi
pointed to “assess ing the needs of condition
monitoring, sensor
technology, surface
treatments and material
technology advancements
in the bearing industry.”
While many of these skills
might not be necessary to craft a
quality bearing, Modi believes that
they offer opportunities for valueadded
integration into electrified powertrains.
All those bells and whistles
can be a genuine selling point if you
can afford to include them, and having
some of those extra credit competencies
can open new avenues to finding
your place in the market.

    There is one last important thing to
note: this article isn’t a blaring klaxon
to get up and get moving. Judgment
day is not dawning on the automotive
market, and life will continue to go on.
Electric transmissions are growing in
importance, and will continue to do
so, but we’re still years away from them
becoming the primary force in the
automotive market.

    Even so, one can never get in on the
ground floor too early when it comes to
establishing oneself as a force in
the industry, and major shifts
like the push for electrification
that create new
opportunities to do just
that don’t come every
day. Competitiveness
is a perpetually moving
metric, and right now, that metric is moving in favor of electricpowered
drivetrains. And while this
isn’t a comprehensive checklist of what
you’ll need to stay competitive in the
years to come, it’ll hopefully at least do
a little to get you thinking about how to
move in lockstep with the times.