Keeping universal joints fully lubricated reduces friction, wear, and heat generation and can significantly prolong the useful life of the assembly. If pre-lubrication, as in needle-bearing joints, or continuous lubrication with oil drips is not attainable, universal joints can be fitted with lubricant-retaining boots (also sometimes referred to as bellows). In addition to maintaining component lubrication, boots can prevent contaminants from entering and damaging the joint.
Figuring Out The Best Universal Joint Boot For Your Application
Standard universal joint boots are typically manufactured from Nitrile. However, special operating environments might require other boot materials and lubricants. Some boot materials are more heat resistant than others. Extreme high and low temperatures can cause changes in the material’s composition as well as make the boots contract and expand past an acceptable range.
Boots can also crack at low temperatures or swell if submerged in fuel or exposed to other harsh chemicals. Such issues can cause oils from the grease to seep through the material. For such operating conditions, the development of alternative boot materials or special design engineering solutions may be necessary, e.g. metal boot covers, bootless universal joints, dry-film lubrication, etc.
A Short Summary of the Different U Joint Boot Material Properties
- Nitrile (standard), also known as Buna-N, has excellent resistance to petroleum-based oils and fuels, silicone greases, hydraulic fluids, water, and alcohol. It possesses high tensile strength and high abrasion resistance.
- Silicone boots are recommended for high-temperature applications. Silicone (-SL) is resistant to high, dry heat. It is also fungus resistant, odorless, tasteless, and non-toxic. It has a high resistance to the aging effects of both sunlight and ozone.
- Neoprene (-CR) was developed as an oil-resistant substitute for natural rubber. It features moderate resistance to petroleum oils and good resistance to ozone, sunlight, and oxygen aging. It has good resilience and is highly resistant to Freon® and Ammonia.
- Viton (-VT) combines high-temperature toughness with wide chemical agent compatibility. It features excellent resistance to petroleum products and solvents.
- EPDM (-EPDM) has excellent ozone and chemical resistance. Effective resistance to steam up to 400 degrees Fahrenheit, hot water, silicone oils and greases, diluted acids and alkalis, alcohols, and automotive brake fluids.
Experience the Belden Difference
Belden Universal has you covered with the u-joint boot required for your application! Please contact us if you’d like to discuss your unique application in more detail. We welcome any feedback and questions and would be glad to hear from you! Give us a call at (708) 578-7716 or contact us online.