Mechanical Maintenance Lecture Notes PDF

Mechanical Maintenance Lecture 3: Introduction to maintenance Introduction Most establishments usually state their primary objectives as: (i) make profit (ii) maximize profit (iii) satisfy a social need/ employ labour (iv) provide useful commodity. Introduction These enumerated o...

Mechanical Maintenance Lecture 3: Introduction to maintenance Introduction Most establishments usually state their primary objectives as: (i) make profit (ii) maximize profit (iii) satisfy a social need/ employ labour (iv) provide useful commodity. Introduction These enumerated objectives should be secondary as if a company can sufficiently identified a market and sufficiently serviced it, all other objectives shall be met. To achieve the primary objective of satisfying a demand, it is very important that products are produced in the right quantity, quality, at the right time and right cost For these requirements to be met Goods must be made in the most efficient and economic manner. The machines and equipment must operate efficiently and effectively at the required level of production. There must be very few or no stoppages on production lines which require effective planning, scheduling and good administration of maintenance activities DEFINITION OF MAINTENANCE Maintenance is any activity that is carried out on any facility either to restore or to retain the facility in a good and acceptable working conditions. Maintenance involves all technical and other procedures performed in order to retain the satisfactory working condition of a machine or part or restoring it to an acceptable working condition so that the set tasks can be performed at the scheduled time and under given conditions. NEED FOR MAINTENANCE Ensure availability of installed facilities Strong competition Tight production schedules Increased machine utilization Increased production level lack of effective and efficient maintenance (i) Excessive machine breakdown (ii) Frequent emergency maintenance work (iii) Shortened life-span of the facility (iv) Poor use of maintenance staff (v) Loss in production output (vi) Inability to meet delivery dates (vii) Excessive overtime (viii) Loss of lives FUNCTIONS OF MAINTENANCE ENGINEERING - primary (i) Maintenance of existing machines and equipment (ii) Maintenance of existing buildings (iii) Inspection and lubrication of machine and equipment (iv) Generation and distribution of utilities e.g. water, electricity etc. (v) Installation of new machines and equipment (vi) Modifications of existing machines, equipment and buildings FUNCTIONS OF MAINTENANCE ENGINEERING - secondary (i) Sanitation (ii) Disposal of used items (iii) Storekeeping (iv) Fire protection (v) Janitorial service Definition of Preventive Maintenance (PM) “Schedule of planned maintenance actions aimed at the prevention of breakdowns and failures” Primary goal-Preserve and enhance equipment reliability Examples of PM Oil changes Greasing Changing filters Belt tightening Anything that increases life of equipment, and helps it runs more efficiently Preventive Maintenance Quiz TRUE or FALSE 1) Preventive maintenance is only necessary on large equipment, such as 100 HP blowers, large gearboxes, etc. Answer FALSE! Preventive maintenance should be performed on most equipment as recommended by the Manufacturer Note: Determine if time spent to perform PM is greater than the replacement cost TRUE or FALSE Equipment manufacturers outline preventive maintenance procedures in the manuals TRUE or FALSE TRUE! Oil and/or grease types, quantities Time periods (weekly, monthly, quarterly) V-belt inspections General visual inspections Torque settings Use these guidelines when creating program Benefits of PM Increases life of equipment Reduces failures and breakdowns Reduces costly down time Decreases cost of replacement Who Does PM? Only trained, qualified maintenance personnel should perform PM’s Why do I need training? To ensure proper techniques and procedures are followed Over greasing is often worse than not greasing enough Improper tightening of packing increases shaft wear and shortens packing life Using improper lubricants can shorten equipment life Predictive Maintenance (PdM) Definition – “Techniques that help determine the condition of in-service equipment in order to predict when maintenance should be performed” Predictive Maintenance (PdM) Primary goal – Minimize disruption of normal system operations, while allowing for budgeted, scheduled repairs Examples of Predictive Maintenance Vibration Analysis Infrared Thermography Oil Analysis Visual Inspections Predictive Maintenance Quiz TRUE or FALSE 1)Predictive maintenance identifies trends and provides historical data Answer TRUE! Predictive Maintenance, such as oil analysis, may show increasing metals in oil sample, indicating breakdown of internal parts. Predictive Maintenance Quiz TRUE or FALSE# Predictive maintenance includes partial rebuild of equipment to keep it running until a complete rebuild can take place Predictive Maintenance Quiz FALSE Predictive Maintenance shows condition of in-service equipment, and predicts when corrective maintenance should be performed. Benefits of PdM Provides increased operational life Results in decrease of downtime Allows for scheduled downtime Allows for money to be budgeted for repairs Lowers need for extensive parts inventory 8-12% cost savings by having a PdM program Who does PdM Often done by a contracted, specialized technician Reasons: 1)Qualified and trained on latest technology 2)Possess the proper equipment 3)Provide trending and historical data in report form Corrective Maintenance Definition – Repair of equipment/machinery in order to bring it back to original operating condition. Corrective Maintenance Important Facts Use original parts Install per manufacturer’s specs Don’t take shortcuts Do it right