HYDRO-TURBINE BEARINGS

Transcription

1 HYDRO-TURBINE BEARINGS

2 PIONEERS IN ADVANCED OIL 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 GM 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.

3 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, environmentallyfriendly alternative to grease and oillubricated bearings.

4 Recommended Thordon Solutions for Hydro-turbine Applications Turbine Main Shaft Guide 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 waterlubricated bearing systems 4 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, environmentallyfriendly main guide bearing system solutions for your hydro-turbines.

5 Wicket Gate and Operating Linkage 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 Pads Offering 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

6 Typical Francis Turbine Applications Thorseal Hydraulic Seal and Thorwipers GM2401 Segmented Main Shaft Guide Bearing HPSXL TRAXL Servomotor Bearing and Thrust Washers SXL Operating Ring Wear Pad SXL Segmented Shaft Seals Thorseal Thorpak HPSXL TRAXL Lower Wicket Gate Bearing with Thorseal 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 7

8 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 Bearings Thordon 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 Seals and Trunnion Bearings Highly 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. 8 Screen Bearings and Wear 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 Bearings Non-polluting Thordon waterlubricated 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 turnaround 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 waterlubricated pump bearing applications. A separate brochure fully outlining the performance benefits and application of Thordon pump bearings is available. Control Gate Bearings Supplied 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.

9 Wicket Gate and Operating Mechanism Seals To prevent contamination of hard-toreach 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 Seals In servo-motor and other hydraulic/ pneumatic applications, high performance, tough Thorseal selflubricating 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 Runner Blade Stem Seals Taking 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

10 Thordon Bearings Offer These Proven 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 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 Greased operating mechanism before installation of Thordon TRAXL bearings. 10 smooth and reliable operation of hydro-turbine and related power plant operating mechanisms. High Abrasion Resistance 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 standardsized bearings, are easily resolved Operating mechanism after installation of Thordon TRAXL bearings. Thordon GM2401 segmented main shaft guide bearings for 2390mm (94 ) shaft at Kranoyarskaya Power Plant, Russia. 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.

11 Accommodates Edge Loading Elastomeric 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. STRESS IMPACT RESISTANCE COMPARISON Higher Tensile Strength R1 R2 STRAIN Lower Tensile Strength 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). RESILIENCE COMPARISON References With 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 MATERIAL Yield Stress Modulus of Modulus of Elasticity Resilience psi MPa psi MPa psi MPa Thordon SXL 3, , Bronze C , x x reference lists by application are available from Thordon Bearings. Wet or Dry Operation Thordon bearings perform well operating either dry, or immersed in water. Lubrication is not required for Thordon bearings operating dry. Hardened Journals Not Required Hard 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 Lip Seals 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

12 Customer Focused To Support Your 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 TBIHA4 03/ BC 3225 Mainway, Burlington, Ontario L7M 1A6 Canada Tel: (905) Fax: (905) info@thordonbearings.com ISO 9001:2000 CGSB Registration #93649 PRINTED IN CANADA