SERVICE & MAINTENANCE
How are you bearing up? PHIL REYNOLDS WORKS IN THE PRODUCT MARKETING DEPARTMENT AT PACCAR PARTS. HERE HE SITS DOWN WITH REPRESENTATIVES FROM TIMKEN AUSTRALIA TO GET THE SPIN ON BEARINGS. wheel bearings is the heavy-duty tapered roller bearing, where the tapered rollers are retained to the ‘cone’ (inner-race) and spaced by a cage, this assembly is then mated with a separate outer-race known as a ‘cup’ and this makes up a complete bearing. This design was first patented by Henry Timken in 1898 and presented the ability to take not only high radial loads (physical weight of vehicle and payload) but also axial or thrust load as the vehicle corners. So why on many axles is the inner bearing larger than the outer? Well in very basic terms, this is because the inboard bearing can be the predominant radialload-carrying bearing in some wheelend designs (hence it being larger and therefore having a greater load capacity) and the outer bearing enables a ‘bearing system’ to be established, finalising the hub ‘set up’ and allowing the ‘bearing system’ to be adjusted to suit the application. The outer bearing also takes axial load in the opposite direction and
PACCAR Parts Product Management, Phil Reynolds.
retains the hub in position.
It is with fond memories I recall my first
Kemp. I wanted to understand more about
Bearing evolution
billy cart where I had rubber wheels to
wheel bearings for trucks and trailers, the
Tapered roller bearing refinement has come a
steer with and just deep-groove ball
history and what advice and knowledge
long way since 1898. Whilst the size of truck
bearings as wheels on the rear. Fish tailing
they could impart to help those who need
and trailer bearings has remained relatively
my way down the footpath as the steel
to service and look after their gear.
constant for many decades, the evolution
ball-bearings struggled for any traction
of bearing manufacturing processes and
as they slid and cut themselves into
Bearing design
materials has seen Timken tapered roller
the concrete was awesome fun (albeit
Ever since Egyptians used logs to roll huge
bearing catalogued load ratings increase
short lived as my Dad seeing the trail of
stone blocks around the concept of a
incrementally over the years which has
scratched concrete put an end to this).
round shape to move product has been
allowed them to keep up with demands for
Since then I have always had a fascination
with us. There are many types of anti-
optimal performance and bearing life. It is
with bearings and their close cousin the
friction bearings but some of the ones you
also important to note, that due to strong
constant velocity joint. I’ve always admired
might be more familiar with are deep-
competition between bearing manufacturers
their form and function.
groove ball bearings, where steel balls are
(that enhance internal bearing geometries
Fast forward to my Product Management
housed between an inner and outer race
with a focus to differentiate their products
role at PACCAR Parts and it is with
and offering good load carrying ability and
and performance) that incompatibility
enthusiasm that I sat down to discuss
reduced friction, then there are tapered
between brands may occur, matching the
bearings with Australian Timken
roller bearings where tapered rollers are
same brand of bearing cup and cone is
Representatives, Scott Hayes and Brad
utilised. The staple of truck and trailer
always recommended.
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Trailer Magazine DECEMBER 21
