PLANE BEARING DESIGN AND MATERIALS Where and When to Use Plastics As A Bearing presented by David Biering Technical Director

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PLANE BEARING DESIGN AND MATERIALSWhere
and When to Use Plastics As A Bearingpresented
by David Biering Technical Director
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(No Transcript)
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PLANE BEARING PRODUCTS
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PLANE BEARING PRODUCTS
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What is a Plane Bearing?

• A plane bearing is any non-rolling element
• Sleeve or flange bushings
• Slide plates
• Friction Bearings
• Any situation where two surfaces rub together is
  a plane bearing

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Plane bearings offer several advantages when
properly applied

• SIMPLE COMPONENTS
• SELF-LUBRICATING
• WIDE RANGE OF ENVIRONMENTS SERVED
• EASY INSTALLATION AND REMOVAL
• LOWER COST

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All plane bearing designs are material
selection problems!

• All designs must include a review of the
  following
• BEARING LOAD P
• BEARING SPEED V
• COMBINED P-V
• TEMPERATURE
• TEMPERATURE VARIATIONS
• ENVIRONMENT

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Bearing Loads are often the most difficult
attribute to define

• PRESSURE (P) Load/Projected Area
• PLBS/ID X LENGTH
• P IS EXPRESSED IN PSI
• Each material is rated for a maximum static
  load (P)?

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The Relative Speed between the shaft and the
bearing is usually easier to define.

• VELOCITY (V) Circumference x RPM
• Circumference (C) TTD/12 in feet
• V is expressed in Surface Feet per Minute
• (SFPM)?
• Every material is rated for a maximum velocity
  (V) at no load

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Pressure (P) and Velocity (V) do not occur
independently and must always be dealt with in
tandem!

• The combination of load and speed generates
  frictional heat
• AS A RESULT WE MUST ALWAYS REVIEW P X V or PV
• Every material has a maximum PV Rating

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Material Rating Overview

• Material Max. PV Max. P Max. V
• Graphite PI 300,000 6,000 1000
• Carbon/PTFE PEEK 100,000 6,000 600
• Tri Steel PE (lubed) 100,000 40,000 2,000
• Tri Steel PI 50,000 36,000 1000
• Oilite Bronze 50,000 2,000 1200
• Carbon PEEK 50,000 6,000 600
• FCJ 20,000 20,000 500
• Ultracomp UC200 20,000 54,500 15
• Ultracomp UC300 20,000 45,000 30
• Rulon 10,000 1,000 400
• CJ 10,000 35,000 150
• Delrin AF 3,000 1,000 100
• Nylon 6/6 1,000 300 360
• UHMW 1,000 800 50

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Other Factors Can Affect The Ability of Plane
Bearing Systems to Handle the P, V and PV

• AMBIENT TEMPERATURE - HIGHER AMBIENT
  TEMPERATURES REDUCE ALL CAPACITIES
• INTERMITTENT OPERATION OSCILLATING AND
  RECIPROCATING MOTION ALLOW HIGHER P, V, AND PV
  VALUES
• SHAFT MATERIALS MATERIALS THAT ARE GOOD
  THERMAL CONDUCTORS ALLOW INCREASED VALUES
• SURFACE FINISH TOO SMOOTH A SURFACE FINISH WILL
  GENERATE HIGHER FRICTION, THUS MORE HEAT, AND
  WILL LOWER VALUES

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MANY PLANE MATERIALS ARE PLASTIC OR PLASTIC LIKE
MATERIALS

• THESE MATERIALS ARE AFFECTED BY HEAT AND ALL HAVE
  A MAXIMUM CONTINUOUS OPERATING TEMPERATURE

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Maximum Operating Temperature of Plastics

• MATERIAL MAX. OPERATING TEMPERATURE F
• Graphite Polyimide 650
• Rulon 550
• TriSteel PI 500
• Carbon/PTFE PEEK 480
• Carbon PEEK 480
• FCJ/CJ 320
• Ultracomp 266
• Nylon 6/6 210
• Delrin 180
• UHMW 180

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Plane Bearing materials have coefficients of
thermal expansion that differ from surrounding
hardware!

• As a result, bearings that operate at elevated or
  extreme low temperatures or function in hot/cold
  cyclic environments must be given special design
  attention.
• Lack of attention to the thermal expansion rates
  of the bearing material will cause seizure or
  bearing drop out

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Plane Bearing Coefficients of Thermal Expansion

• MATERIALS EXPANSION IN/INF x 10E-6
• Tri Steel PT 6.0
• 1040 Carbon Steel 6.0
• FCJ 7.0
• CJ 7.0
• Carbon Fiber PEEK 7.0
• 660 Bronze 10.0
• Aluminum 12.4
• Carbon/PTFE PEEK 17.0
• Graphite PI 27.0
• Ultracomp 33.0
• Rulon 35-49.0
• Nylon 6/6 55.0
• Delrin AF 63.0
• UHMW 130.0

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A major strength of plane bearings is their
ability to function in a wide range of
environments

• Wet fresh, salt, DI, slurry
• Dirty coal, quartz, sand, road ballast
• Chemicals full pH range
• Clean rooms minimal debris production
• FDA/USDA/3A/NSF approvals
• AND ALL THIS WITHOUT LUBRICATION!

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How do self lubricating plastics bearings
lubricate?

• There are two types of lubrication methods in
  plastic plane bearings
• Smearing systems small amounts of lubricating
  additives such as PTFE, silicone, graphite or
  MOS2 are wiped into the microfinish
• Debris systems small particles of the polymer
  are removed during normal operations and develop
  plastic ball bearings

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Smearing Systems

• Smearing systems are typical of PTFE and PTFE
  filled polymers
• As the shaft makes initial contact with the
  mating contact surface, softer lubricating
  material is wiped into the microfinish of that
  surface building a thin film of lubricant
• Lubricant remains in place and will not migrate
  out thus reducing the friction and wear on both
  the shaft and the bearing.

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Smearing System Materials

• Best know materials utilizing this type of self
  lubricating process
• Rulon
• Fluorosint
• PTFE Blends
• Delrin AF
• Ertalyte TX
• BG PEEK
• Graphite PI
• TriSteel PT/PI
• Ultracomp

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Debris Systems

• Debris systems are found in harder thermoplastic
  or thermoset polymers that deposit particles of
  the actual resin between the shaft and bearing.
• These types of materials tend to be less
  efficient since the debris remains on the surface
  area between the dynamic faces rather than
  embedding.
• Over time the debris is cast off as residue
  and the wear process tends to be on a slow but
  continuous basis.

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Debris Systems Materials

• Nylon 6/6, 6/12
• Acetal/Delrin 100/500
• Cast Nylons
• UHMW
• It should be noted that debris materials have
  inherently low friction but not as low as
  smearing systems with migratory lubricants.
• It should also be noted that debris materials
  tend to be lower cost than the smear materials
  but they also have lower P,V,PV ratings and
  limited temperature ranges.

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Materials Review

• By far, the largest family of self lubricating
  plane bearings are the filled PTFE materials.
• The best known of these is Rulon, a family of
  blended PTFE materials designed for bearings,
  seals and structural components.
• Fluorosint family of mica filled PTFE for low
  thermal expansion applications

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Rulon Bearings
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Rulon Bearings

• Rulon is a product from Saint Gobain Performance
  Plastics Formerly Dixon-Furon
• Family of products has over 300 blends
• Tri Star Plastics is the Master Distributor for
  Rulon products in North America

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Rulon Bearings

• All Rulon materials have similar properties
• Temp. Range - -400 to 550/600F
• Inert to all chemistry
• Zero moisture absorption
• Self Lubricating
• Variable thermal expansion properties
• Outstanding wear life and strength

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Most Common Rulon Bearing Materials

• Rulon LR maroon color, ceramic fiber filled,
  excellent creep and wear resistance, low friction
  best used against 35RC hardness or better
• Rulon J gold color, lowest friction of any
  plastic, non abrasive so will run against soft
  shaft materials
• Rulon 641 white color, FDA grade for food
  processing and packaging applications
• Rulon 142 blue/grey color bronze filled for
  extremely low deformation, excellent sliding
  bearing for machine tools, motor mounts, slide
  pads

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Rulon Availability

• All Rulon materials are available in standard
  sleeve, flange and thrust sizes to match bronze
  standards
• Rulon is also available in rod, sheet, tape or
  tube for in house machining
• Rulon is very easy to machine and Tri Star can
  assist with techniques.

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Bearing Grade Composite Materials

• The newest generation of self lubricating plane
  bearings are composites
• Ultracomp family of very high load, low speed
  bearing materials for high impact and vibration
  applications on oscillating pin bushings
• CJ filament wound rigid epoxy bearing for
  extreme loads in oscillating or rotary
  applications. PTFE/Nomex liner on ID for low
  friction and long wear life
• FCJ filament wound rigid epoxy bearing for
  extreme loads in full rotary or linear
  applications. Alloyed PTFE liner for increased
  speed ratings. Lower load rating than CJ and
  Ultracomp

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Ultracomp

• Ultracomp is a made using synthetic fibers and
  impact resistant thermoset resins for extreme
  loads.
• Ultracomp bearings have static load ratings of
  54,500 psi to break and 18,500 psi to yield.
• Ultracomp is primarily a high load, low speed
  oscillating material.
• All Ultracomp materials have less than 0.1 swell
  in water
• All Ultracomp materials have migratory lubricants
  such as PTFE, graphite or MOS2

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Ultracomp
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Ultracomp

• Ultracomp materials are used in construction,
  agriculture, material handling, railway, and
  general industries for pin bushings, slide pads,
  spherical inserts, trunnion support bearings,
  etc.
• Ultracomp is easy to machine
• Ultracomp is an excellent replacement material
  for lubricated steel or bronze bushings

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CJ Bearings

• CJ bearings are off the shelf replacement
  bearings to bronze standards
• CJ bearings use filament winding techniques at
  different helix configurations to improve
  strength through the wall.
• Nomex/TFE blended liner gives excellent wear life
  and lubricity
• CJ bearings have very low swell in water and are
  thermally stable for tight tolerance designs

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FCJ Bearings

• FCJ bearing is similar to the CJ but the
  Nomex/TFE liner is substituted with a alloyed
  PTFE tape liner
• Lower load limits than CJ but higher speed rating
  for full rotary applications without lubrication
• Excellent wear and friction properties

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TriSteel Metal Backed Bearings

• TriSteel bearings are metal bearings with various
  self lubricating liner materials sintered into
  the substrate
• Liner materials vary depending on loads and
  speeds
• Liner materials include PTFE, Acetal, PEEK,
  PI/PTFE blends, PTFE/PVDF blends
• All TriSteel bearings have very high P, V and PV
  ratings and have extremely low deformation

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TriSteel Bearings
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Tri Steel Bearings

• Tri Steel bearings are available with tin or
  copper plated steel, 316 stainless or bronze.
• Liner materials will vary in thickness from .002
  to .020
• Wall thicknesses are .060 and .090 nominal

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TriSteel Bearings

• TriSteel bearings are capable of PV ratings up to
  80,000 without lubrication and 2 million with
  lubrication
• Temperature ratings vary from -400F to 500F
• PEEK/SS grade excellent substitute for rolling
  element bearings in chemical pumps and other
  rotary equipment

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Tri Steel Bearings
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High Performance Materials

• An additional group of plane bearing materials
  are the HPM grades
• PI polyimide with graphite additives can
  operate at 700F without lubrication and with
  extremely low wear. PV ratings as high as 300,000
  in some conditions without lube
• Trade names - Meldin, Vespel, Duratron

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High Performance Materials
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High Performance Materials

• High Performance Materials are catagorized as
  imidized materials and advanced hybrid polymers.
• Imidized materials include
• Celazole PBI
• Polyimide Vespel, Meldin, Duratron
• Polyamide-imide Torlon
• Kapton polyimide film

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High Performance Materials

• PBI Highest temperature polymer on the market
• HDT of over 800F with continuous service over
  750F and short term excursions to 1100F
• Ionic impurities very low
• Very strong material without any fillers
• Lowest coefficient of thermal expansion of any
  unfilled plastic
• Highest compressive strength of any unfilled
  plastic
• Excellent thermal insulator
• Inherently good wear properties without PTFE

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High Performance Materials

• Polyimides
• True condensation polymer with excellent wear and
  thermal properties
• Vespel best known trade name. Meldin family is 8
  different versions of polyimide
• Compression, isostatic or injection moldable.
  Also available in thin cast films known as Kapton
• Unfilled and filled versions available for
  different bearing or structural needs

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High Performance Materials

• Another family of HPM products is Torlon which
  is a PAI.
• Excellent wear life at extreme speeds without
  lubrication
• PV values up to 3 million with lube
• Used as sleeve or thrust bearing in
  transmissions, gear boxes, final drives, etc.
• Thermally stable, coefficient of thermal
  expansion close to steel

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High Performance Materials

• PEEK available with carbon fiber, graphite
  powder and PTFE fillers for outstanding high
  load, high speed rotary applications
• Inert to most chemistry, able to work in steam or
  high temperature liquids
• Very low thermal expansion, excellent wear life
  and low friction

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Other Bearing Grade Materials

• There are many more engineering grade plastics
  used in bearing applications
• PET Ertalyte, Ertalyte TX
• PBT - Hydex
• PPS Ryton, Techtron Poor Mans PEEK
• Cast Nylons (Nylatron)?

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Final Comments

• Tri Star Plastics specializes in material
  development, design and fabrication of self
  lubricating plastic bearings.
• Our interest is in assisting customers with
  product selection, component development and
  successful production.
• Our website www.tstar.com is interactive and you
  can use our online design assistance to determine
  potential materials for your application.

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Final Comments

• Tri Star looks forward to working with you as you
  investigate improved performance, longer life and
  more cost effective bearing systems for your
  equipment.
• Remember No lube/No maintenance!

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Supplier Recognition

• Ultracomp Tri Star Plastics Hydex
  Ensinger/Hyde
• TriSteel Tri Star Plastics Ertalyte - Quadrant
• Delrin E.I. DuPont Ryton - Phillips
• Celazole Quadrant Torlon Solvay Chemical
• PEEK Victrex CJ/FCJ Saint Gobain EPP
• Teflon E.I. Dupont Duratron - Quadrant
• Rulon Saint Gobain EPP Techtron - Quadrant
• Nylatron Quadrant Fluorosint - Quadrant
• Nylon E.I. DuPont
• Meldin Saint Gobain EPP
• Vespel E.I. DuPont Some names are
  registered tradenames of
  various companies.
• Values indicated are typical. Tri Star recommends
  testing in your particular application to insure
  performance expectations are met.