Machinery Lubrication

Machinery Lubrication November-December 2018

Machinery Lubrication magazine published by Noria Corporation

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www . | November - December 2018 | 35 ML ML to your maintenance activities, you can add some direction and conti- nuity to a daily process. Although preventive maintenance can help reduce the chaos of failures, it can still result in high maintenance costs when good parts are replaced. More recently, new tools and accessories have become available to aid in equipment monitoring and catching potential issues earlier. is monitoring of failure symptoms and faults is known as predictive mainte- nance. e most common forms of this approach include using vibration analysis, ultrasound, thermography, oil analysis and a host of other tech- nologies to provide an early warning of an impending problem. Predictive maintenance works well for machines that run continuously and often results in a reduction of unplanned downtime. However, it usually comes with considerable upfront costs, not just for the necessary tools but also in training the individuals who are expected to capture the pertinent data. Diligence is required to ensure data is collected from the same place and in the same manner each time. Inconsistent practices will skew the data and make it much more diffi cult to take appropriate action. Rather than fixing machines, proactive maintenance eliminates what causes them to fail. It can be used to extend equipment life, as opposed to simply improving the process for repairs or identifying when a machine is going to fail. Proactive maintenance focuses on the root causes of failure and addresses them before they lead to an eventual problem. Much of proactive main- tenance occurs before a machine is ever turned on, including alignment and balancing. Without a proactive mindset, equipment failures will continue to plague most maintenance departments. Analyzing what went wrong and taking steps to prevent it from happening again are the hall- marks of being proactive. Lubrication Activities In a lubrication program, there are tasks for applying lubricants, analyzing their state and eventually disposing of them once they reach the end of their useful lives. Beyond these front-line tasks are manage- ment activities to ensure work is completed properly. Perhaps the simplest lubrication task involves the use of a grease gun. However, these devices have been improved in recent years and now incorporate advanced technology. Before utilizing a grease gun, be sure to consider the task in relation to the diff erent maintenance philosophies discussed previously. Reactive Greasing You've likely heard the phrase, "the squeaky wheel gets the grease." W hen performing lubrication in a reactive state, you wait until an issue is experienced before adding grease to a bearing or machine. But greasing in response to a noise or elevated head is very reactive. By the time these symptoms arise, damage has already occurred. Preventive Greasing Greasing a machine according to a calendar date or number of operating hours is pervasive in the industry, but adding grease based on time may lead to overgreasing or undergreasing the machine. Although it can help prevent some failures, a lot of manpower will be used to maintain the preventive maintenance (PM) program. Predictive Greasing Predictive tools for greasing have gained popularity in recent years due to their ability to identify precise intervals and grease volumes to add. Ultrasound is frequently employed to listen to a bearing and detect if and how much grease is needed. is type of greasing requires an educated staff and the necessary tools, but it can greatly reduce, if not eliminate, the likelihood of overgreasing a machine. Grease sampling and analysis are also becoming more widely used to deter- mine the health of the grease and the machine as well as the optimum relubrication frequency. Proactive Greasing By balancing all the best practices, you can be more proactive with your greasing. is begins with selecting the right grease for the application. For critical applications, it may also include sampling the grease prior to use to verify its cleanliness. Also, perform the appropriate bearing calculations to confi rm the correct grease volume and to guide your future activities. is same methodology applies to oil applications. While you may rely on the rotating motion of a machine to apply oil to various internal 4 Oil Analysis Strategies Oil analysis falls into the realm of condition monitoring but can be used in various ways to determine what is happening inside a mechanical system. It also can be divided into four different strategies: REACTIVE — An oil or grease sample is taken only after a potential problem is identifi ed via a sensory inspection. PREVENTIVE — Routine samples are extracted, but the results are not analyzed. PREDICTIVE — Good samples are obtained and analyzed, with action taken on results from the lab. PROACTIVE — New lubricants are sampled prior to service. Samples are taken from the right place, in the right way, using the right tests and with the right interpretation strategy. 43 % of lubrication professionals say their plant uses a proactive maintenance strategy, based on a recent poll at Machinery-

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