Lubron Fiberglide is ideal for oscillation, vibration, full rotation and linear applications. Wrapped bushings, wear plates, and thrust washers are available in both metal and non-metal backed options. Fiberglide excels in the 2,000 to 10,000 psi load spectrum and has a low coefficient of friction.
Fiberglide/Fabroid bearings are being used by many basic manufacturing industries where they have proven their economy, convenience and dependability.
- Aerial Work Platforms
- Steering systems for trucks, farm tractors, off-highway equipment
- Heavy-duty suspension systems of trucks, tractors and related equipment
- Brakes for trucks, automobiles, off-road vehicles
- Transmission shift linkages and pivots
- Butterfly, ball plug valves
- Clutches and variable speed sheaves
- Marine equipment
- Pneumatic and hydraulic tools and actuators
- Conveying and material handling equipment
- Recreational vehicle suspension and controls
- Packaging machinery
- Textile machinery
- Wherever heavy loading and low speed oscillations are encountered
Fiberglide/Fabroid is a proprietary self-lubricating bearing material of woven polytetrafluoroethylene or PTFE fibers applied to a rigid backing. To assure the best possible bond between PTFE fibers and backing material, a secondary, more readily bondable fiber (which may vary with application requirements) is interwoven with the PTFE fibers presented on the bearing side of the fabric.
Fiberglide/Fabroid bearings are unique in their ability to resist cold flow under extremely high loads because the monofilament fibers have a tensile strength approximately 25 times greater than straight PTFE resins. Cold flow is also minimized by the effective entrapment of the fiber bundles by the high-strength bonding resins.
Fiberglide/Fabroid bearings are completely self-lubricating and normally run dry. However, they can also be used where lubricating or other fluids are present. Operating dry, Fiberglide/Fabroid bearings are recommended where low surface speeds are combined with high loads.
Fiberglide/Fabroid bearings are available with many backing materials in a wide variety of standard configurations. In addition, Transport Dynamics offers special bearings with an almost unlimited range of configurations and metal backings.
Fabroid liners are designed to carry higher loads with improved wear life. Fabroid liner types are woven PTFE glass fabrics utilizing various thermoset resins depending on product type. This construction leaves the PTFE fibers exposed on the working surface without contact to the resin. A resin is used in the prepeg and as the bonding adhesive. Due to the construction, the liner is highly compressible and able to absorb distortions in mating surfaces, and has a low fiction surface from the start with no break in period.
MAINTENANCE-FREE SELF LUBRICATING BEARINGS
Many factors affect the overall performance of Fiberglide/Fabroid bearings. Those of primary concern include applied load, surface velocity, operating mode, surface temperature, mating surface finish and running clearance.
All performance values referred to in this section are based on dry operation. When running in a fluid atmosphere, Fiberglide/Fabroid bearings may have limitations. Where application requirements exceed those shown, consult Transport Dynamics engineering department for specific recommendations.
Fiberglide/Fabroid lined bearings are designed to be used under oscillating motion, interrupted start-stop, impact loading or axial motion. They are recommended where high loads, are combined with low surface speeds.
Bearing wear is affected by many factors. For the most part, tests conducted by Transport Dynamics subject journal bearings to 20,000 psi loads with the bearing fixed and the shaft oscillating.
It will be noted that a wear-in period takes place during the first few thousand cycles. During this period some PTFE is transferred to the mating surface. In addition, the fibers are generally reoriented, the high points of the weave are flattened and adjacent fibers tend to blend together. After the break-in period, the bearing surface will become smooth and shiny.
Because of the many variable which influence wear, it is extremely difficult to project bearing life for all types of applications. For this reason, the Transport Dynamics engineering department should be consulted when questions of this nature arise. Wear life calculations are based on rubbing distance of travel.
Bearing Load limits
Static Pressure Limit (Constant Pressure)
10,000 (70 Mpa) psi with phenolic backing
38,000 (262 Mpa) psi with steel backing
Dynamic pressure limits while oscillating
20,000 psi (140 Mpa) suggested maximum with steel backing
Under dry running conditions, the maximum allowable surface velocity will depend on the applied load and other operating parameters. In general, surface speed should be kept below 35 FPM (Feet Per Minute) (11 m/min) at 10,000 psi (70 Mpa) load or 600 FPM (183 m/min) at 100 psi (.7 Mpa load)
For plain, dry-running bearings, it is often helpful reference a pressure-velocity (PV) factor as a guide in determining bearing capability. It should be understood that this factor is actually a variable which reflects the point where surface temperatures are at a maximum, but are still stable.
The maximum PV established for Fiberglide/Fabroid is:
Normal operating temperatures should be kept below 300°F (149°C) for standard Fiberglide/Fabroid bearings. An increase in wear rates may be experienced at temperatures above 350°F (177°C). Note that at elevated operating temperatures, the PV limit will be decreased in order to prevent the surface temperature from exceeding 300°F (149°C), (environmental temperature plus friction heat generated). When temperatures exceed 300°F (149°C) or fall below -200°F (129°C), consult Transport Dynamics engineering a department for specific recommendations.
Coefficent of Thermal Expansion
When bonded to a metal backing, Fiberglide/Fabroid's coefficient of expansion can normally be regarded as identical to that of the backing.
Fiberglide/Fabroid, being a non-metallic, will operate against most metals, but better performance is obtained with the hardest available mating surfaces. Hardened steel, hard anodized aluminum, hard chrome or nickel plate are recommended. A surface hardness is desirable, but satisfactory performance can also be obtained with softer materials. Generally, a surface finish on the mating components of 16-32 μinch (0.4-0.8 μm) should be provided. Shaft materials or surface treatments should be selected that will effectively resist corrosion.
Coefficient of Friction
Coefficient of friction depends upon type of movement, finish of mating surface, ambient temperature, bearing pressure, velocity and other variables.
Fiberglide/Fabroid can tolerate small amounts of dirt, but reduced bearing life will result. Optimum life is achieved if dirt or abrasive particles are excluded. If a dirty environment is likely, we recommend installation of a simple seal.
As a general rule, close running fits, and often slight interference fits (.0005 in., .013 mm) are selected for oscillating motion when minimum starting torque is less important than the elimination of free play. For constant rotation, a free-running fit is normally recommended, the exact amount depending on a bearing bore size. A rule of thumb would be 0.0015 inches per inch (.038 mm) of bore (bearing installed).
Bearing housing & Shaft Sizing
Standard Fiberglide/Fabroid journal bearings (CJS/CJT/CJM/CJH/SJS Type) are installed into the housing bore using a press fit. Recommended housing bores should be held to the tolerance shown to ensure the proper fit and size.
The LJS Type bearing is a hand slip fit into its recommended housing bore to provide optimum fit-up. CJS/CJT/CJM/CJH types can also be provided for slip fits on special order.
Transport Dynamics offers a free service to properly recommend housing and shaft sizes for each new application. Contact Transport Dynamics engineering department for details.
Fiberglide/Fabroid can tolerate most fluids or contaminants found in bearing applications, although some reduction of dry bearing life will result. Fluids tend to flush PTFE solid particle lubricants out of the bearing. Grease tends to act as a magnet to attract and retain dirt.
Following are some of the environments in which these bearings have operated successfully:
- Hydraulic Oils
- Mild Acids
- Lubricating Oils
- Detergent Solutions
- Ammonium hydroxide
- Liquid Nitrogen
Fiberglide/Fabroid bearings offer 18 distinct advantages over conventional lubricated bearings:
- Design freedom-Fiberglide/Fabroid bearings can be incorporated into internal component assemblies inaccessible to conventional lubrication technique, eliminating costly maintenance tear down.
- Maintenance free-The self-lubricating nature of Fiberglide/Fabroid makes it an ideal selection for equipment providing service to remote environments such as oil and gas transmission lines and pumping stations.
- Operation without lubrication while tolerating many lubricating and non-lubricating fluids.
- Environmentally friendly, lead-free, green product.
- High dynamic load carrying (up to 20,000 psi).
- Inherent vibration and noise dampening qualities.
- Low coefficient of friction.
- Freedom from stick-slip.
- Absence of cold-flow tendencies of solid and filled PTFE resins.
- High resistance to fatigue under shock loads.
- Eliminating fretting corrosion.
- Resistant to attack by most substances.
- Operation at temperatures beyond the range of most lubricants (-320ºF to 400ºF).
- Fiberglide bearings have been tested to have 7-10 times the life of a DU Product.
- Good dimensional stability.
- Compatible with a wide range of mating materials.
- Electrically non-conducting.