Pressure-dam Journal Bearing

This TRI “Pressure-dam” Journal Bearing is one of a series of “drop-in” bearings that TRI manufactures to be used in American-Standard Fluid Drives.  These TRI Bearings  are manufactured to a semi-finish size as a spare part and then finished to specific diameters required by the application.  This  permits journals to be machined undersize to be round and concentric, removing prior damage or flaked chrome plating.  The Bearing OD can be sized to suit the actual pedestal bore diameter.  TRI uses steel backings instead of a bronze/brass to avoid the problems associated with “Copper-Tin Embrittlement and Debonding” that often occurs with the OEM journal bearings.

 

 

 

 

 

 

Elliptical Bore Bearing with Spherical OD

This TRI Elliptical Bore Journal Bearing with spherical outside surface is a new bearing using a backing made from forged or heavy plate steel.  The Babbitt bore lining is centrifugally cast at TRI.  There are only two pieces in this bearing, a top half and a bottom half. The dowel pins are pressed into the joint surfaces so they will not get lost or damaged. They can be extracted, if necessary. TRI recommends that the bearings be manufactured with an undersize bore so that the bore can be machined at time of installation to suit the then-existing journal diameter.  This  permits journals to be machined to be round and concentric, and bearing bores machined to suit the precise journal diameter without rebabbitting.

 

 

 

 

 

 

Elliptical Bore Bearing with Insulation and  Spherical OD

This TRI Insulated Elliptical Bore Journal Bearing is a new multi-piece bearing using an inner bearing backing and an outer bearing backing made from forged or heavy plate steel.  The Babbitt bore lining is centrifugally cast at TRI.  Each half of this bearing consists of two separable steel parts and a separable insulator sheet made of NEMA Grade G-10, all bolted together. The outside surface is spherical and is sized to suit the spherical seat of the supporting pedestal or bearing bracket of a  generator or an exciter/ GE Alterrex.

 

 

 

 

 

 

 

Elliptical Journal Bearing for Reactor Feed Pump

This TRI Elliptical Bore Journal Bearing is designed for and used in a new Reactor Feed Water Pump.  It is designed for pressure-fed lubrication.  The bearing is supported by a short cylindrical fit in the center of the bearing.  A saddle block is mounted on the top to be used to adjust the fit to the bearing housing cover.   This bearing replaces a cylindrical bore bearing with oiling ring lubrication as well as pressure fed lubrication.  Elimination of the open slot for the oiling ring permits the elliptical design to function properly to control rotor vibration.  The steel backing is a forged steel ring.

 

 

 

 

Bearings for Exciter Gearbox for WECO T-G

A set of 4 TRI Bearings with 4 and 5 inch bores being manufactured for an Exciter Gearbox for a WECO T-G.   In this case, TRI rebuilt the entire gearbox, starting with the journal bearings, including one with tapered land thrust faces (not shown). The bearing housings were rebored round with parallel shaft centerlines. New hardened and ground gears were designed, purchased, and installed, replacing hobbed gears.   New thermocouples were installed. When installed, in the plant, the gear bearings were properly loaded. The end result was a smooth running gearbox and exciter.

 

 

 

 

 

16” Elliptical Bore Bearing  with Spherical OD

This TRI 16 inch Elliptical Bore Journal Bearing is a new two-piece bearing using an upper and lower half made from a single forged ring of low carbon steel.   The Babbitt bore lining is centrifugally cast at TRI.  There are three saddle blocks, two on the bottom at 45 degrees from the vertical and one at the top center.  The outside surface of the saddle blocks is spherical and is sized to suit the spherical seat of the supporting standard/pedestal of a Westinghouse turbine.  Each saddle block has tangential and radial shims to permit quick, accurate alignment changes.

 

 

 

 

 

 

 

TRI 18” Bore Bearing for Nuclear Powered Turbine

TRI designed this 18” bearing to be installed in a yoke support of a WECO turbine that was being retro-fitted with uprated  steam turbine rotors. The bearing has a series of features that improve its usefulness to the application compared to the original OEM bearings. One feature is the use of six “saddle blocks” that seat the bearing in the yoke.  Also, shims on the saddle blocks are adjusted so that the yoke elastically deforms under the weight of the rotor, yet the bore of the bearing remains round. 

 

 

 

 

 

 

TRI 24” Bore Bearing for Nuclear Powered Turbine

This 24 inch bore bearing is a sister of the above 18 inch bearing.  This 24 inch bearing is shown seated in a yoke. The bore of the yoke was machined with a spherical bore to remove years of distortion and fretting. The outside surface of the bearing is spherical and is machined to suit the spherical seat of the yoke. The saddle blocks have both radial and tangential shims, sometimes called primary and secondary shims, to make fitting and alignment adjustment easier.  In the final fitting process, these shims are adjusted to obtain high percentage contact without hand-working the surfaces of the saddle blocks.

 

 

 

 

 

 

TRI 12” Elliptical Bore  ID Fan Journal Bearing

This TRI  Elliptical Bore Journal Bearing is designed for a large heavy Induced Draft Fan.  This bearing is designed for pressure fed lube oil so that it is no longer a ring-lubricated bearing. In so doing, the top half of the bearing is continuous from end to end, not interrupted with open slots for oiling rings.  The bearing has a tapered-land thrust face on each end used to locate the rotor axially. The spherical fit on the OD of the bearing matches the spherical bore of the supporting fan bearing housing.

 

 

 

 

 

 

 

 

TRI Thin-wall Elliptical Journal Bearing

This TRI Elliptical Bore Journal Bearing is one of a series of “drop-in” bearings that TRI manufactures for Gearboxes for GE Frame 5 GT-Gen Sets.  These TRI Bearings  are manufactured to a semi-finish size as a spare part and then finished to specific diameters required by the application.  This  permits journals to be machined to be round and concentric, removing prior damage.  The Bearing OD can also be sized to suit the actual gearbox housing bore diameter.  TRI uses alloy steel backings to provide high-strength to the bearing structure.   This upgraded TRI Journal Bearing is designed for use in gearboxes where the GT has been uprated to 30 MW (from 19.6 MW).  In this upgraded condition, the gear-tooth separation forces increase in proportion to the MW.  The OEM bearings cannot take this additional loading, but these upgraded TRI journal bearings can.  At the same time, at very low loads, the elliptic design of these TRI bearings controls sub-synchronous rotor vibration.

 

 

 

 

 

TRI Elliptical Journal Bearing in  Gearboxes

This photo demonstrates a thin-wall TRI Elliptical Bore Journal Bearing installed in a Frame 5 Gearbox.  With TRI’s design approach of spare bearings with oversize ODs, used gearboxes with distortion can have the bearing housing bores rebored.  The housing bores for the two shafts can be  made parallel again in order to minimize wear of the gear teeth. This will result in oversize housing bores, but the new bearing liners can easily be made to match. In addition to manufacturing these bearings for customers, TRI also refurbishes entire gearboxes, using gears made to the user’s specification.  TRI typically purchases gears of AGMA grade 12 or13 or higher made by world class gear manufacturers. TRI also manufactures oil seals for the gear shafts to control loss of lube oil.

 

 

 

 

 

 

TRI Vertical Radial Guide Bearing

A class of Vertical Radial Guide Bearings was recently designed and developed by TRI for service in large vertical Circulation Water Pumps such as used in power plants. 

TRI has applied for a US Patent to cover the novel features and methods of manufacture: A US Patent is Pending.

Performance advantages include: Considerably cooler bearings, and very low rotor vibrations.  

This upgraded TRI bearing design replaces corresponding guide bearings that have alternate diagonal oiling grooves (45 degrees to the left, then 45 degrees to the right) milled into the Babbitt bore. 

Other advantages of this upgraded TRI Journal Bearing include:  After rotation of the journal is initiated, lube oil is pumped to the top of the bearing within one-half rotation.  A higher flow rate (gpm) of oil flows through the bearing, assuring that the oil film is full. Larger areas of uninterrupted bearing surfaces permit higher oil film pressures to occur, resisting rotor motion and minimizing vibration. A higher portion of the  lube oil that reaches the top of the bearing is directed through passageways out to flow over the cooling coils. Oil supply passageways take cooled oil entering inlet ports drilled in the outside surfaces of the bearing and direct the lube oil into viscous pumps milled in the Babbitt bore. From there, the oil flow repeats itself.  

TRI can provide measurably improved performance enhancements for your vertical pumps by applying these recently developed design and manufacturing principles to new or refurbished guide bearings for your applications.