10 Reasons to Use Composite Bearing Washers

These thin round disks help align, protect, and support a thrust ball or roller bearing in various types of applications. Washers for bearings were traditionally from durable materials like stainless, or other steels, though bearing washers are increasingly made from composites due to their advantageous material properties. Precisely machined to ensure they fit correctly between the housing and shaft, bearing washers prevent direct contact between the rolling elements of a bearing. Washers made from composites have characteristics that help reduce mechanical stress and wear while also helping distribute loads across a bearing, increasing the bearing’s lifecycle.

10 Reasons to Use Composite Bearing Washers

The use of bearings in their varied iterations has augmented the growth of many industries, while revolutionizing transportation and otherwise improving the quality of life in modern societies. Also known as bearing shims, bearing spacers, friction washers, and thrust washers, bearing washers are a key bearings component. Due to their many and varied material traits, composite bearing washers are often chosen, which offer superior performance. There are myriad reasons to use composite bearing washers, rather than washers made from other materials.

Ten reasons to use composite bearing washers include:

• Abrasion-resistance: Offering better resistance against wear, composites resist abrasion better than metals and alloys, ensuring longer lifespans for bearing washers.  
• Corrosion resistance: While metal alternatives have a propensity to rust and otherwise corrode, composite bearing washers resist chemicals, solvents, and other environmental conditions that can cause corrosion better than metals, alloys, or other materials.
• Customizable: Composites can be engineered to have specific material properties, such as chemical resistance, corrosion resistance, dielectric strength, dimensional stability, heat resistance, high strength-to-weight ratio, and other attributes.
• Dimensional stability: Composites can retain their form and integrity when exposed to heavy loads or temperature extremes, and they enhance bearing washers’ wear resistance.
• Lower maintenance: Due to their self-lubrication, abrasion-resistance, and other properties that help them resist wear, composite bearing washers require a reduced amount of maintenance and replacement less frequently.
• Modulus of friction: Bearing washings made from composites have low-friction surfaces that augment efficiency and decrease energy loss in rotating mechanisms, which is even more true when the composite is self-lubricating.   
• Self-lubrication: Composite materials infused with glasses containing materials like phosphates and silicates, metal salts like oxides and sulfides, mica, nanomaterials, softer metals like indium and tin, talc, or other self-lubricating materials decrease the necessity for external lubricants.
• Sound absorption: Composites can better absorb shocks and dampen loud noises caused by friction, vibrations or other sources, leading to quieter operation.
• Surface compatibility: Composite bearing washers are less damaging to the surfaces of housings and shafts, reducing wear on these and other components they contact. 
• Weight: Bearing washers made from metal or alloys weigh considerably less. Their lighter weight makes them especially useful for components used in the aerospace, automotive, or other sectors where weight is a factor.

Bearing washers are critical components within machinery, operating under tremendous loads while handling harsh materials and toxic substances. The best bearing washers are made from robust materials like composites, with properties that maintain lubrication and allow them to handle these contaminants.  

Composites Used for Bearing Washers

Composite bearing washers come in various formulations, with each engineered composite offering advantages for specific applications.

PTFE-Based Composite Bearing Washers

Composites made from PTFE (polytetrafluoroethylene) with molybdenum disulfide offer optimal mechanical traits, while their chemical inertness ensures they resist nearly every kind of acid, chemical or solvent. PTFE-based composites can withstand heat up to 260°C (500°F), making them good for high-heat applications. Additionally, as PTFE offers greater flexibility, bearing washers mate well with other parts, increasing wear resistance. With its incredibly low friction coefficient due to its self-lubricating properties, PTFE-based composites are useful for bearing washers for aerospace components, as well as in medical devices due to PTFE’s biocompatibility. Additionally, equipment in the food processing industry uses non-toxic, food-grade PTFE in composites that ensure FDA (Food and Drug Administration) compliance.

POM-Based Composite Bearing Washers

Composite bearing washers made with POM (polyoxymethylene) offer self-lubricating traits with a low friction coefficient, providing good wear-resistance. Along with their resistance to chemicals, oils, solvents, and weaker acids, these traits also allow POM-based bearing washers to perform well in toxic environments where lubricants can’t be supplied continuously. These bearing washers require only minimal maintenance, though they can also handle heavy axial loads due to their stiffness and strength, while not being as sensitive when misaligned. POM-based bearing washers work best in applications involving slower oscillational or rotational movements. This includes automotive components like gearboxes and steering mechanisms as well as conveyors, pumps, and other industrial equipment. Due to their moisture resistance and low water absorption rate, these composites also do well in marine environments.

Fiberglass-Reinforced Epoxy Bearing Washers

These composites include FR-4, G-10, and G-11, all used for bearing washers. Along with their rigidity and high mechanical strength, these composites additionally insulate against electricity and resist chemicals. G10-based bearing washers are stable over a wide range of temperatures and are often used for cryogenic applications. Due to their moisture resistance, both G-10 and G-11 composites are often used in marine environments, though G-11 performs better under high-heat conditions. Often found in washer bearings for various electrical components, fiberglass-based composites are also used for filament wound tubes, which are engineered with specific traits to modify electrical resistance or conductivity as well as applications involving extreme temperatures. Fiberglass-reinforced epoxies also perform well for components in aerospace applications and industrial equipment.

Bearing Washers Made from Phenolic Resin Composites with Fabric 

Cotton, linen, paper-based laminates, and other fabrics mixed with phenolic resins provide good strength-to-weight characteristics, while damping, self-lubricating, and shock absorbing properties give these composites decent wear resistance. Though these composites offer good chemical resistance, over time phenolic resins absorb moisture. Generally, bearing washers made from these composites are used in automotive and marine applications, as well as for components within heavy equipment.

Composite Bearing Washers Reinforced with Carbon Fibers 

Referred to as carbon fiber reinforced polymers (CFRP), bearing washers made with this composite have an incredible strength-to-weight ratio. Bearing washers made with CFRP also exhibit a low friction coefficient, contributing to their excellent wear resistance. Along with these properties, the fact that CFRP doesn’t expand when exposed to high temperatures makes it ideal for aerospace, automotive, and other high-performance industrial applications.

Composite Bearing Washers Reinforced with Aramid Fibers 

Also known by the brand name Kevlar®, aramid fibers are perhaps best known for their durability and impact resistance, as they are used in bullet-proof vests and other attire. With a low friction coefficient, these aramid-based composites resist abrasion and wear well while also offering considerable resistance to chemicals and moisture. Because of their ability to perform satisfactorily in high heat conditions, they’re often used for bearing washers for industrial pumps, along with mining, marine, and high-load applications. 

Polyamide-Based Bearing Washers Filled with Glass-Fibers 

Composites made from nylon 6 and nylon 66 are often used for bearing washers due to their greater dimensional stability than standard polyamides, along with their resistance to chemicals, moisture and oils. With a decent load-bearing capacity and excellent resistance to wear, these engineered composites work well for high-impact applications, especially in the food processing, industrial machinery manufacturing and transportation sectors.

Graphite-Filled Composite Bearing Washers

Composite bearing washers filled with graphite self-lubricate, so generally last longer. Graphite-filled composites not only resist wear but are chemically inert and corrosion-resistant as well. Graphite-filled composites decrease buildup of heat due to their thermal conductivity properties. Because these composites can handle high speeds and electrical loads, they’re often used for bearing washers in compressors, pumps, and high-speed rotating machinery.

Composite Bearing Washers from Spaulding 

Bearing washers are a product that Spaulding Composites Inc. has fabricated for many decades, especially for drivetrains and transmissions in heavy machinery. We understand that these bearing washers must be exceptionally durable while also being able to maintain constant lubrication and withstand contaminants. This is why some of the world’s biggest businesses have turned to Spaulding Composites for engineered solutions for bearing washers and other bearing components.

Spaulding offers a range of composite materials tailored to a customer’s specific needs. These materials span the gamut from high-performance substrates to inexpensive cotton fabrics, including custom weave blends containing aramids and cotton. Spaulding’s engineering team has the means to customize resin matrices to enhance performance while also designing for extended lifespans, manufacturability, prototyping, and other applications. To learn more about our capabilities, contact the composite experts at Spaulding today.