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How to Deal with Extreme U-Joint Applications

Submitted by nick on

Real-life industrial applications often deviate from the ideal scenario for a mechanical system. Rather than a temperate and dry environment, your application may be hot and humid. Instead of a dust-free, clean room, your u joint might be subjected to dirt, corrosive chemicals, or seawater.  If your application is particularly dirty, hot, corrosive, or unusual in some other way, this article discusses how to size, maintain, and extend the life of u-joints for extreme applications.

Surviving Dirt

Abrasive particles in industrial environments can significantly shorten the life of a u-joint. U-joint Boot Covers are the simplest solution for blocking out contaminants and are strongly recommended for the following applications:
•    Actuators
•    Aggregate conveyors
•    Bakeries
•    Compactors
•    Farm equipment
•    Foundry conveyors
•    Pumps
•    Milling plants
•    Stone crushers
•    Woodworking and Paper Processing


A corrosive environment can spell trouble for many types of mechanical systems. Corrosion can significantly impact the performance of a u-joint. Seals, boots, and coatings are essential for preventing corrosion by forming a barrier against the electro/chemical process.

Belden offers a wide variety of solutions for corrosive environments, including several grades of stainless steel and specialty coatings and platings to keep your u joints functioning well.


Heat can affect u-joint performance by causing bearings to lose their lubricity and boots to sag and lose their elasticity, leading to lubricant loss and accelerated wear. Switching to a synthetic high-temperature bearing lubricant is recommended for applications near heat sources such as furnaces, ovens, or engine exhaust. Belden can also supply boot materials with heat resistant properties.

Overload Capacity

Unexpected overloads can occur in various high-torque applications. Unfortunately, there is no set rule for determining the required overload capacity. Experience is the only guide. Belden’s Engineering team will be happy to consult with you on your specific application and to share what we have seen work in the past. Where safety factors are critical to personnel or operational safety, they must be determined experimentally.

Vibration and Fatigue

Vibration can cause fatigue and premature pin failure in u-joints. Here are some ways to minimize vibration:
•    Minimize misalignment: Misalignment generates vibration as the joint redirects torque.
•    Balance rotating parts: An unbalanced rotating part can cause vibration throughout the system.
•    Straighten bent shafts: Bent shafts are a major source of vibration and must be repaired.
•    Avoid resonance: Avoid operating equipment at a speed that causes vibration at or near its natural frequency.

With proper planning, it is possible to extend the life of your u-joints used in extreme applications and ensure optimal performance. The Belden engineering team is happy to answer any additional questions you may have.