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 info@thordonbearings.com

www.thordonbearings.com

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