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H Y D R O - T U R B I N E B E A R I N G S
PIONEERS IN ADVANCEDOIL AND GREASE FREE
HYDRO-TURBINE BEARINGS
With over 25 years experience supplying main shaft guide, pump, wicket gate
and operating mechanism bearings to the hydro power industry, Thordon is the
proven choice for performance and value in both rehabilitation and new turbine
projects. Superior technical support and customer service provides customers with
bearing solutions that meet, or exceed, their specifications. Depending on the
application, the optimum bearing may be selected from among several Thordon
grades and configurations.
Continuing polymer research and development by Thordon resulted in the
introduction several years ago of HPSXL TRAXL, a high pressure elastomer product
polymerized in a metal housing. This configuration is recommended as the optimum
choice for higher pressure bearing applications such as wicket gate and operating
linkage bearings in hydro-turbines. Other Thordon grades such as full form HPSXL,
SXL or GM2401 - where higher levels of abrasives are encountered - are recommended
options for main shaft guide, pump and other lower pressure bearing applications.
High performance Thorseals are tough, self-lubricating, polymer seals specified for
sealing wicket gate and operating mechanism bearings, butterfly valves, Kaplan
runner blade stems and general hydraulic and pneumatic applications including
servo-motor pistons and rams.
Today, with installations ranging from micro-turbines to units with main shafts up
to 3.7 m (94”) diameter, Thordon is a recognized leader in the design,
manufacture, supply and installation of bearing solutions for the hydro-turbine
industry. All Thordon bearing systems are designed and manufactured to ISO
9001:2000 Quality System requirements.
In 1995, the largest hydro-turbine manufacturer in Russia - LMZ, after
exhaustive testing of a number of bearing materials, entered into a joint
venture agreement with Thordon International Inc. A joint venture
company, Interplast, was formed to produce and supply Thordon
bearings to LMZ for the Russian and former Soviet Union markets.
For hydro power producers and turbine manufacturers who
demand the best in performance, value and service;
environmentally-friendly Thordon hydro-turbine bearing
systems offer the proven solution.
Thordon Bearings is recognized as a pioneer
in high performance, yet environmentally
friendly, innovative bearing system designs.
Thordon provides reliable, cost effective
bearing solutions to the hydro power, marine,
offshore and pump industries. Originally
developed in 1967 as a high performance
pump bearing, Thordon is an elastomeric
polymer alloy offering excellent wear life and
low operating friction, while providing a
dependable, long-lasting, environmentally-
friendly alternative to grease and oil-
lubricated bearings.
4
Recommended Thordon Solutionsfor Hydro-turbine Applications
Turbine Main ShaftGuide Bearings
Thordon Bearings recommends
two bearing grades for use in
water-lubricated turbine main
guide bearings. Thordon SXL offers
the lowest coefficient of
friction, superior adhesive
wear performance and
good resistance to wear
resulting from third particle
abrasion. Thordon GM2401
is specially formulated
to provide optimal wear
resistance in abrasive-laden
water conditions, routinely
outwearing rubber bearings
by a factor of two or
more, yet, still exhibiting a
significantly lower coefficient
of friction compared to rubber.
Thordon bearings can be
specified as an upgrade for
rubber or other non-metallic
bearings in existing water-
lubricated bearing systems
or as a complete conversion
from sealed oil or grease lubricated
systems to pollution-free water
lubrication. Although elastomeric
in nature, Thordon bearings,
particularly SXL, are significantly
stiffer than rubber. A high degree
of resilience, however, is still
maintained and running clearances
similar to rubber are possible.
Thordon main shaft guide bearings
are usually supplied factory-bonded
into split bearing housings, or on
larger bearings, on to multiple guide
blocks. If required, bearings
can be supplied in stave
configuration as well.
A reference list of main shaft
guide bearing installations
ranging up to the giant 3.7
metre (94”) shaft diameter
bearing units installed in the
Kranoyarskaya hydro power
plant in Russia is available from
Thordon Bearings.
Choose water-lubricated
Thordon SXL or GM2401
turbine main shaft guide
bearings for reliable, long
wearing, environmentally-
friendly main guide bearing
system solutions for your
hydro-turbines.
Wicket Gate and OperatingLinkage Bearings
Thordon HPSXL TRAXL bearings are
recommended for use in wicket
gate and linkage bearing system
applications. HPSXL, an enhanced
elastomer product introduced by
Thordon several years ago, offers even
better friction and wear performance
operating either wet or dry than SXL
TRAXL. HPSXL TRAXL achieved a top
level overall rating in the Powertech
simulation test for wicket gate and
operating linkage bearings.
Homogenous Thordon HPSXL
incorporates friction and wear
reducing additives throughout its
entire molecular structure ensuring
consistent performance in limited
motion applications. The cost,
maintenance and pollution risks
associated with greased bearings are
eliminated. Stiffer than SXL but still
elastomeric in nature, HPSXL performs
well under edge loading conditions
created by minor misalignment or
wicket gate deflection. HPSXL deflects
slightly, effectively spreading the
load, reducing the unit pressure
and eliminating the potential for
galling on the edge.
Easily machined, Thordon HPSXL
TRAXL bearings can be sized prior
to installation, or easily line bored after
installation, to correct misalignment
and dimensional inconsistencies
encountered during turbine
rehabilitation. Bearings are often
supplied with overbuild to facilitate
finish machining on site. Manufactured
in Canada, Thordon bearings can be
supplied quickly to meet tight
rehabilitation project schedules.
Thordon HPSXL TRAXL is the proven
choice for long wearing, low
friction wicket gate and operating
mechanism bearings.
Operating Ring Wear PadsOffering smooth, grease-free operation
and high abrasion resistance, Thordon
SXL is recommended for vertical and
horizontal operating
ring wear pads. Usually
supplied molded to
size complete with
stainless steel inserts for
mechanical fastening, SXL
wear pads can also be
bonded in position using a
Thordon adhesive.
Servo-Motor and Servo-Link Bearings
Thordon HPSXL TRAXL bearings are
recommended for the servo-motor
and servo-link positions. Elastomeric
HPSXL is able to accommodate the
minor misalignment that often
occurs at these bearing locations and
grease lubrication is eliminated.
5
Typical Francis Turbine Applications
Thorseal
Hydraulic
Seal and
ThorwipersHPSXL TRAXL
Servomotor Bearing
and Thrust Washers
SXL Operating
Ring Wear Pad
HPSXL TRAXL
Lower Wicket Gate
Bearing with Thorseal
GM2401 Segmented
Main Shaft Guide
Bearing
SXL Segmented Shaft Seals
Thorseal Thorpak
6
7
Typical Kaplan Turbine Applications
SXL Water Lubricated
Main Shaft Guide
Bearing
HPSXL TRAXL
Linkage Bearings
and Thrust Washers
HPSXL TRAXL
Upper Wicket
Gate Bearing with
Thrust Flange
HPSXL TRAXL
Middle Wicket
Gate Bearing
Kaplan Turbine
Runner Blade
Stem Seals
Segmented Shaft Seals
Tough, abrasion resistant Thordon
SXL segmented shaft seals provide
extended wear life and reduced life
cycle costs compared to carbon
graphite-based seals. Thordon shaft
seals are supplied molded to size.
Wicket Gate Thrust BearingsThordon HPSXL gate thrust collar
bearings eliminate the greasing
system required with conventional
designs. Elastomeric HPSXL’s
inherent resilience and low
coefficient of friction ensures smooth
gate operation with no stick slip.
Thordon typically incorporates the
thrust bearing into the upper
head cover bearing by polymerizing
HPSXL onto a flange on the bearing,
but separate thrust bearings can also
be supplied.
Butterfly Valve Sealsand Trunnion BearingsHighly abrasive resistant, tough and
compliant, Thorseal butterfly valve
seals offer extended wear life and are
resistant to damage resulting from
debris becoming lodged in the valve
during operation. Thordon HPSXL
TRAXL valve trunnion bearings
operate smoothly and easily, without
grease lubrication, as a result of
HPSXL’s low coefficient of friction.
Screen Bearings andWear Pads Resilient, and highly resistant to
abrasion, Thordon SXL is an obvious
choice for the shaft bearings and wear
pads used in travelling and stationary
screens. Non-corroding Thordon
bearings offer extended wear life and
eliminate the maintenance, cost and
pollution risk associated with grease
lubrication. In some of the higher
pressure locations, such as the upper
shaft of travelling screens, HPSXL may
be recommended due to its higher
pressure capabilities.
Pump BearingsNon-polluting Thordon water-
lubricated pump bearings offer
dry-start capabilities, long wear life,
low friction and superior resistance to
abrasive wear. Available in three
grades, Thordon pump bearings
can be selected to optimize
specific performance requirements.
From Thordon Composite for highly
abrasion resistant bottom bowl
bearings, to Thordon SXL for dry-start
upper bearings, Thordon pump
bearings often outperform rubber
bearings by a factor of
two or more in abrasive
conditions. Not limited
to a range of standard production
sizes or by shelf life, Thordon
pump bearings facilitate quick turn-
around and reduced maintenance
inventories. Costly sleeve or shaft
replacement can often be avoided by
machining a pre-grooved Thordon
tube to the exact non-standard
dimensions required. Thordon
bearings are the proven choice for
value and performance in water-
lubricated pump bearing applications.
A separate brochure fully outlining
the performance benefits and
application of Thordon pump bearings
is available.
Control Gate BearingsSupplied in ball and socket, or
bushing and pad configurations for all
types of control gate applications,
Thordon HPSXL bearings, with their
low coefficient of friction, operate
smoothly and easily without grease
lubrication. Abrasion resistant and
resilient, Thordon bearings provide
long wear life and are not damaged by
the impact loading resulting from
frequent control gate operation.
8
Wicket Gate and OperatingMechanism SealsTo prevent contamination of hard-to-
reach wicket gate bearings by
abrasive laden waters, or operating
mechanism bearings by corrosion
residue or other contaminants, seals
are recommended. High quality
Thorseal lip seals are formulated from
a tough, high strength polymer
impregnated with internal lubricants
and are supplied as an integral part of
the bearing design.
Hydraulic/Pneumatic SealsIn servo-motor and other hydraulic/
pneumatic applications, high
performance, tough Thorseal self-
lubricating polymer lip seals offer
positive sealing up to 100 MPa
(15,000 psi). Thorseals provide long
wear life with no need for periodic
adjustments; resist tearing and
extrusion; and as a result of their
internal lubricants, operate with less
drag and reduced cylinder wear.
Available as a single ring U-cup
(Thorseal), rod wiper (Thorwiper),
piston cup with reinforcing centre disc
(Thorcup) and nested V-ring chevron
configuration (Thorpak), Thorseals
are not only available in a wide
range of standard sizes, but can
also be quickly machined to custom
size requirements up to 1.5 m (60”)
in diameter.
Kaplan Turbine RunnerBlade Stem SealsTaking advantage of the tough, long
wearing Thorseal polymer lip seals,
an enhanced sealing design has been
developed for Kaplan runner blade
hubs. Essentially, two specially
designed Thorseal single ring U-cup
seals are locked together to function as
a monolithic double acting seal and
fitted back to back in the blade shaft
stuffing box. The outer seal lip prevents
ingress of water into the hub and the
inner seal lip stops oil from leaking out
of the hub into the environment. The
Thorseal design is easy to install,
resists distortion during blade
positioning and the modified lip design
allows for positive sealing under
significantly more blade droop than
packing. Shaft wear is reduced due to
the friction and wear reducing
additives in the polymer and the
seals can be supplied split for easy
in-situ replacement.
9
Thordon Bearings Offer TheseProven Operator Benefits
Long Wear Life
References from over 25 years
experience supplying main guide,
pump, wicket gate, operating
mechanism and a variety of bearings
for other hydro-turbine applications
have proven that Thordon bearings
provide long wear life, often
significantly longer than the bearings
they replace.
In the standardized US Army Corps
of Engineers tests simulating over
15 years of normal turbine operation
conducted by Powertech Labs,
Thordon HPSXL TRAXL operating dry
showed virtually zero wear. Bearing
journal wear was also very low.
Low Friction Thordon bearings exhibit very
low coefficients of friction. The
in-use coefficient of friction of
HPSXL operating dry or wet is
typically in a range from 0.06 to
0.12 while SXL ranges from 0.08
to 0.15. More importantly, the
difference between the static and
dynamic coefficients of friction is low,
ensuring that “stick-slip” will not be
a problem. A low bearing coefficient
of friction is essential for the
smooth and reliable operation of
hydro-turbine and related power plant
operating mechanisms.
High AbrasionResistance
Superior wear life, when operating
in third party abrasives, is a
consequence of Thordon’s elastomeric
nature. Thordon tends to deflect, and
then reject, abrasive particles
allowing them to pass through the
bearings. Typically, other non-metallic
bearings tend to deform plastically,
allowing the abrasive particles to
bed into the bearing surface,
creating a permanent abrasive
against the shaft.
Sizing Flexibility – Easily Machined
Thordon bearings are typically
supplied finish machined to the
customer’s specifications, however,
due to dimensional uncertainties,
they can also be supplied with ID and
OD overbuild and easily machined on
site to the exact sizes required.
Dimensional inconsistencies, or
issues with misalignment, that
can cause problems for standard-
sized bearings, are easily resolved
by supplying Thordon bearings in a
semi-finished form and machining
on site. Optimum alignment and
clearances for “problem” turbines are
easily ensured.
A free machining elastomer, Thordon
contains no asbestos or other
hazardous materials, machines
cleanly and does not produce
nuisance dust during machining.
Pollution Free
Thordon polymer bearings are
specially formulated with friction
and wear reducing additives to
provide smooth operation and
long wear life without the use of
grease or other lubricants. Any risk
of pollution is eliminated. The
lubricant additives are dispersed
evenly through the homogeneous
polymer structure. This ensures
the lubricant is always available at
the bearing surface to maintain a
lubricant transfer film as the bearing
wears. Some bearing designs,
such as metallic bearings with
lubricant plugs, installed in a turbine
application may not experience
sufficient shaft rotation to fully
disperse the lubricants and galling or
binding may result.
10
Thordon GM2401 segmented main
shaft guide bearings for 2390mm
(94”) shaft at Kranoyarskaya Power
Plant, Russia.
Greased operating mechanism
before installation of Thordon TRAXL
bearings.
Operating mechanism after
installation of Thordon TRAXL
bearings.
Accommodates Edge LoadingElastomeric Thordon bearings
perform well under edge loading
conditions created by minor
misalignment or component
deflection. Thordon deflects slightly,
effectively spreading the load,
reducing the unit pressure and
eliminating the potential for galling
on the loaded edge.
High Resilience/Impact Resistance Elastomeric Thordon bearings
exhibit a Modulus of Resilience over
20 times greater than bronze,
and several times greater than
other common non-metallic
bearings. As a result, Thordon
bearings can absorb impact loads
encountered during operation to a
much greater degree than bronze or
other non-metallic bearings. Tensile
strength, although one of the key
indicators in defining a material’s
physical properties, is of less
importance in selecting an optimum
radial bearing.
ReferencesWith over 25 years experience
supplying main shaft guide,
pump, wicket gate and operating
mechanism bearings to the
global hydro-turbine industry,
environmentally-friendly Thordon is
the proven choice for performance
and value in both rehabilitation and
new turbine projects. Extensive
reference lists by application are
available from Thordon Bearings.
Wet or Dry OperationThordon bearings perform well
operating either dry, or immersed in
water. Lubrication is not required for
Thordon bearings operating dry.
Hardened Journals Not RequiredHard journals are required for hard
bearings. With Thordon
bearings, standard 304 or
316 grade unhardened
stainless steel journals or
pins machined to 0.8 µM
(32 µinches) or better
surface roughness are
adequate.
Polymer LipSeals
High quality Thorseal lip
seals are recommended
for sealing HPSXL TRAXL
bearings in applications where
third particle abrasives are
encountered, Kaplan runner blade
stem seals and servo-motor and other
conventional hydraulic/pneumatic
seal applications. Formulated from
a tough, high strength polymer
with internal lubricants, Thorseals
provide effective sealing, low friction
and long life.
11
RESILIENCE COMPARISON
Thordon SXL 3,500 24.1 88,000 608.0 306.0 2.11
Bronze C93200 20,000 138.0 14.5 x 106 100 x 103 13.8 0.10
MATERIAL Yield Stress Modulus of Modulus of
Elasticity Resilience
psi MPa psi MPa psi MPa
The Modulus of Resilience of a material is
the area under the elastic portion of the
stress/strain curve. This graph illustrates
why a high tensile strength material has a
much lower resilience (R1), than a lower
tensile strength material with higher
resilience (R2).
Higher Tensile Strength
R1
R2
Lower Tensile Strength
STRAIN
ST
RE
SS
IMPACT RESISTANCE COMPARISON
Customer Focused To SupportYour Immediate and Future needs
Supply and Service: Geared to provide
quick response to customer needs,
Thordon Bearings understands the
importance of quick delivery and reduced
down time. Thordon hydro-turbine
bearing systems can be designed,
produced to the exact requirements of
the customer and shipped quickly.
Distribution: With Thordon bearings
specified all around the world, an
extensive distribution network has been
established in over 70 countries.
Inventories of common bearing sizes are
stocked by local Thordon Distributors and
are backed up by large regional and head
office Thordon stocks.
Application Engineering: Thordon
Bearing’s engineers work closely with
customers to provide innovative bearing
system designs that meet or exceed the
technical requirements of the application.
Manufacturing: Thordon’s modern
polymer processing facility is staffed
with experienced and dedicated
employees. Bearings up to 2.2 m (86")
in diameter have been supplied and
bearings up to 1.5 m (60") O.D. have been
machined in-house.
Quality: Thordon Bearings Inc. is
a Canadian company manufacturing
to ISO 9001:2000 Quality System
requirements. With over 30 years
experience in elastomeric bearing
design, application engineering and
manufacturing, Thordon hydro-turbine
bearings are recognized worldwide for
both quality and performance.
Research and Development: Thordon
bearings are being continuously tested by
our Bearing Test Facility. The Facility
evaluates new designs and applications
before they are put into service. Ongoing
testing not only allows for design
refinements, but ensures quality and
performance after installation. Our polymer
laboratory evaluates new and modified
polymers in a continuing quest to improve
Thordon bearing performance and search
for new polymer bearing solutions.
Your local Thordon Distributor
3225 Mainway, Burlington, Ontario L7M 1A6 Canada
Tel: (905) 335-1440 Fax: (905) 335-4033
E-mail [email protected]
www.thordonbearings.com
TBIHA4 03/03 4000 BC
ISO 9001:2000CGSBRegistration #93649
PRINTED IN CANADA