The past and present of lubrication management  

From the invention of the wheel, and the discovery that animal fat smeared on axles would ease movement, right through to the cutting-edge machines of today’s heavy industry, lubrication has been integral to the story of humanity’s innovation and development. The scientific discovery of friction; the rise of petroleum lubricants; and the advent of synthetic solid, semisolid, and liquid lubricants are all part of the story. Lubrication management is the latest advancement improving the performance of the machines that make the world turn. 
 
Today, lubrication and sealing are critical to the performance of the total machine. And it’s widely recognized that the fundamental challenges in sealing moving machine parts are establishing a good sealing system and ensuring long service life. Inextricably linked, solving these challenges is crucial to effective application performance. However, sealing and lubrication are often overlooked by plant management, whose maintenance budgets may be allocated elsewhere. Focusing on these though has positive benefits; lack of effective lubrication is identified as the primary cause of premature machine bearing failure. 
 
Lubrication management is more than simply choosing and applying a lubricant. It’s managing and adjusting the lubrication conditions of all elements within a sealing system that reduces the load on each element and optimizes performance in terms of friction-wear lifetime. This holistic approach to machine maintenance focused on the friction points of the seals and bearings is necessary because the interfaces between surfaces in motion are constantly subjected to pressure and wear.  
 
Effective lubrication management begins with the end in mind. Given the complexity of today’s industrial machines, suitable lubrication management takes a strategic, problem-solving approach. Reducing unplanned downtime and cost, while maintaining the integrity of the sealing system, requires assessment of potential issues before devising a solution comprising of materials, application, and maintenance.  
 
The challenge 
The world is dynamic, and because of this, products are subject to failure. Energy continually shifts from one state to another, while prevention of perpetual motion is by friction, wear, and resistance at the atomic level. In this physical universe, lubrication is one way of holding back the tide of entropy, the lack of available energy to do mechanical work. Lubrication makes equipment run smoother, perform more efficiently, and last longer. The battlefronts for lubrication are a machine’s seal contact areas, or friction points; effectively lubricating these can be the difference between costly repairs and smooth running. 

The exponential growth of technology, and resultant demands of an ‘always-on’ world, mean that today’s machinery is increasingly dynamic, more intricate, precision-engineered, and efficient. But this doesn’t mean machinery can break the laws of physics. Friction, wear, and pressure all pose threats to this machinery, potentially causing part failure, service downtime, and cost. And in applications in which seals, from O-Rings to rotary shaft seals, play a critical safety and operational role, the challenge of friction and wear is multiplied exponentially. 

Friction is the great enemy, impacting hydraulic systems and seals in a variety of ways. Therefore, when designing a lubrication management system, it’s important to consider all factors, including:  

1. Pressure and speed: Smaller and lighter machines have led to an increase in pressure and speed of hydraulic applications, pushing polyurethane materials to their sealing limits. 
    

2. Coating of counter surfaces: When chosen for mechanical and functional reasons, often no consideration of the sealing system is given in selection of coatings. This can severely limit the lifespan of both the seals and the machinery. 
    

3. Rough surfaces: Tiny imperfections, embedded holes, uneven textures, and friction-creating characteristics in the interfacing surfaces of high-speed applications may abrade the seal as it passes. 
    

4. Modifications and post-processing: Making seal modifications in isolation of the system overall to extend seal life and prevent wear can be costly.  

The solution  
Applying lubricants to seals under pressure loads can extend the life of the seal and mitigate the effects of friction and wear. However, this is a simplistic view, given the previously mentioned speed and pressure challenges of modern machinery, as well as the mandatory need for redundancy in critical industrial applications.  

In fluid power and hydraulic sealing applications, best practices involve the use of primary and secondary seals in tandem. The primary seal does the grunt work, maintaining integrity for as long as possible; the secondary seal is a redundancy measure, ready to step in when needed.