Manual or Automatic Lubrication? How to Decide
Lubrication is an essential part of machinery maintenance for nearly every production facility. On average, lubricant purchases only amount to 3 percent of a maintenance budget, but lubrication-related activities can influence an estimated 40 percent of total maintenance costs.
In order to achieve optimum reliability and maximum benefits from a lubrication program, several factors need to be taken into account. These factors are summarized by the five R’s of lubrication:
- Right lubricant
- Right quantity
- Right time
- Right point
- Right method
The starting point of an effective lubrication program is the detailed mapping of all lubrication points, including their working conditions, lubrication requirements, and criticality. This information is needed to select the most suitable lubricant and the quantity of lubricant needed, as well as to calculate the adequate relubrication intervals. These are the first three R’s.
The fourth “R” refers to best practices, such as tagging and color-coding (or other methodology) of both lubrication points and tools in order to avoid cross-contamination.
Maintenance Costs Influenced by Lubrication-Related Activities
Besides lubricant costs, half of the acquired components will require relubrication. Overtime, labour is mostly a result of machine failures typically caused by inadequate lubrication. In addition, approximately 5 percent of labour costs can be attributed to lubrication activities.
The fifth “R” can be defined once the application conditions, asset criticality, and maintenance strategy are analysed. This will help you decide whether to automate each lubrication point. To make that decision, the pros and cons of automatic lubrication should also be understood and considered.
Once the five R’s are defined, you can determine the best way to lubricate a component with the resources available.
A thorough criticality analysis of each asset will illustrate the impact of a failure in terms of:
- Overall production cost
- Overall maintenance cost
- Environmental impact
- Health and safety of personnel
The most critical assets are commonly the first targets of automatic lubrication.
The maturity level of a maintenance program (corrective, preventive, predictive, etc.) will dictate the skill and knowledge level required of personnel involved in lubrication-related activities.
As the maturity of maintenance and associated lubrication programs increases, so does the complexity of tasks that lubrication technicians must be capable of completing. These include activities such as:
- Lubricant analysis
- Continuous adjustment of lubrication routes
- Contamination control and fluid reconditioning
- Inspection routes
Therefore, as more mature maintenance programs are adopted, the areas where skilled maintenance technicians can add value to your operations need to be carefully considered. For example, are they best utilized performing manual relubrication, which can easily be automated, or by using their skills and knowledge to perform more analytical tasks, lubricant analyses, and making improvements to the lubrication program?
Benefits of Automated Lubrication
There are many advantages to using automatic lubrication systems. These include reduced waste and risk of bearing failure, cleanliness, less labour, and improved environmental health and safety. The benefits of this system can be seen across multiple industries. For example, an automatic lubricating system would be ideal for pharmaceutical industries where they have to deal with multiple types of equipment, harsh environments, and hundreds of lubrication points. By having this system, they ensure their machines are working at peak performance to produce a quality product every time.
Reduced Waste and Risk of Bearing Failure
Relubrication quantities are dictated by the physical space available in the bearing, while relubrication intervals are dictated by the working conditions that determine the degradation rate of the lubricant. This includes factors such as speed, load, temperature, and the type of bearing.
A single-point automatic lubrication system can deliver the right amount of grease at the right time to each lubrication point. This reduces both grease waste and the risk of bearing failure. Especially when such system is coupled with ultrasonic sensors and a remote monitoring system, lubricating based on bearings’ condition, assuring perfect lubrication at the right time, always.
One good example is the OnTrak & Smartlube from UE Systems.
Consider, for example, a bearing that needs to be relubricated with 2 grams of grease every week. With a standard grease gun, this would mean that the bearing should receive about 1.3 “strokes.” However, manually delivering 0.3 strokes is difficult, and it would likely result in a full two strokes being delivered. In other words, the bearing would receive 3 grams instead of 2 grams each time.
If we assume the technician is satisfied with two strokes because he doesn’t see any grease coming from the seals, after a year, the bearing will receive 156 grams (52 weeks times 3 grams per week) instead of 104 grams (52 weeks times 2 grams per week). This means that up to 52 grams (50 percent) of the grease will be wasted.
An automatic lubricator can supply a continuous and accurate flow of fresh and clean lubricant.
Lubricant contamination will also affect bearing life and increase the risk of failure. In manual lubrication programs, avoiding grease contamination can be a challenge.
Processes must be clean to ensure no external contamination ingress into the grease, and each lubrication point should have a cap on its grease fitting. In addition, the utmost clean relubrication process for each point must be followed every time.
In the previous example, the technician will relubricate the given point 52 times a year. As a result, the bearing will be exposed 52 times to external contamination as well as to over-and under-lubrication.
By comparison, a properly installed single-point automatic lubricator can supply a continuous and accurate flow of fresh and clean lubricant, keeping the application in proper condition while at the same time preventing contaminant ingress.
When to Use Automatic Lubrication
Automatic lubrication alone certainly is not the solution to all your lubrication issues. It must be properly understood to boost its potential benefits. However, there are solutions available in the market for virtually every application, so it is difficult to imagine that a critical application is not worth equipping with an automatic lubrication device.
When companies wish to reduce the energy cost of their industrial facilities, finding and repairing existing compressed air leaks is an excellent starting point. But such a task requires time, personnel, and the right tools. Thus, efficiency is key when it comes to carrying on a leak detection program. And, right now, nothing is more efficient than using an ultrasound camera.
It is estimated that 60-80% of bearing failures are related to lubrication. Bearing failures very often lead to unplanned downtime, which often has a significant impact on production and related equipment. This downtime is maby times very costly. Although the costs vary according to the severity of the incident and the industry in question, they do add up to production costs.