Page 16 - Dana Glacier Bearings Materials Brochure, designed and produced by Connell Marketing Associates, UK

Material Development
and Testing

Test machines capable of investigating the various facets of plain bearing behaviour are
essential to the development of bearing materials, optimisation of manufacturing routes,
and the understanding of bearing systems. Test methods are constantly under review to
ensure that the optimum simulation of bearing operating conditions are achieved.

Testing Methods

FLYW HEEL SAPPHIRE L-N FATIGUE TEST

FLEX IBLE 1000
CO UPLING

TEST BEARING S LUBRICATIO N
O IL INLET
DRIVE M OTO R
SLAVE
B EA RIN GS

EC CENTRIC 100
TEST SHAFT

10 1.00E +06 1.00E +07 1 .0 0E +0 8
1.00E +05

STRAIN REVERSE LO AD SCUFF SEIZURE TEST SCHEDULE
GAUGES HYDRAULIC O IL
CONTROLLED PRESSURE OUTLET 140
REVERSE LO AD
HYDRAULIC O IL CON ROD 120
G UDG EO N PIN
IN L E T 100
PISTO N
80BEARING SPECIFIC LOAD (MPa)
FO RWA RD LO AD FO RWA RD LO AD
HYDRAULIC O IL HYDRAULIC O IL 60
CONTROLLED PRESSURE OUTLET
IN L E T 40

20

0
0 100 200 300 400 500 600 700
TEST DURATION (seconds)

Principle of Sapphire test rig. Principle of Saturn, Jupiter, Mercury, Pluto and Oscar Rigs.

Two basic groups of test The rigs can operate over a wide A further special test machine
machines are employed at Glacier range of temperatures and can Scorpio has been developed to
Vandervell, those relating to the accommodate a range of bearing assess flow erosion resistance, a
function of crankshaft bearings sizes. Via the computer control performance characteristic
and those relating to bushes. In system, a programmed progressive important to polymeric bearings in
practical terms this generally load increase becomes the basis of shock absorbers and strut, gear
translates to metallic materials a measurement of surface properties. pump and hydraulic motor
and polymers. In this mode the minimum oil film applications.
thickness steadily reduces and the
For crankshaft bearings the test measures scuff resistance or In addition to supporting material
prime considerations are fatigue conformability. This is defined as a and process development the
strength and surface properties. system’s ability to accommodate bush test rigs are used to identify
The Sapphire test rig represents minor geometrical inaccuracies of product operating envelopes under
the major investigative tool for sliding surfaces. Seizure resistance a wide range of conditions.
these fundamental bearing or compatibility is the ability of two This yields information which can
properties. This machine, surfaces to be in contact without be of direct use to a customer’s
developed originally by Glacier system failure. design engineers. To this end a
in the 1950’s, is now widely large number of rigs operate
used around the world and is An in depth understanding of the 24hrs/day almost 365 days a year.
the premier choice for leading bearing system as a whole is The entire system is continuously
bearing manufacturers. The fundamental to the optimisation of monitored and controlled by a
Glacier Vandervell Technical crankshaft bearing materials and computer which will automatically
Centres now have ten such design. The test rigs developed by terminate a test after a pre-selected
computer controlled machines Glacier Vandervell, particularly the wear, temperature or duration has
all at the most modern state of Sapphire machine, play an important been achieved.
development. role in expanding our knowledge of
system interactions of which the
The operating principle is bearing is just one part.
as follows:
Test bearings, fitted to a For bush materials, generally
connecting rod/piston assembly, polymers, wear, friction and erosion
operate against a test shaft with a are the main criteria. Glacier
small eccentric. The resultant Vandervell developed the special
piston motion is resisted rigs Saturn, Jupiter, Pluto, Mercury
hydraulically thus imposing a and Oscar to measure bush wear
sinusoidal dynamic load on the under various sliding conditions, -
test bearing. Fatigue strength plain rotational, linear reciprocating
may be measured utilising a and rotational oscillating. A range of
staircase approach to determine load and speed conditions can be
the load to fatigue or failure or covered and also lubrication from
alternatively the fatigue life may dry through oil, grease water and
be measured at a fixed load to other fluids. The Libra rig additionally
obtain a load-life relationship. provides for friction measurement.

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