MIME 2230-Workshop Technology
Chapter-7-Workshop Maintenance

Need For Machine Tool Maintenance
• To keep the machine tool in proper working condition always
• To endure the accuracy
• To minimize breakdown
• To ensure production without any interruption
• To use at the optimum capacity
Types of Maintenance
Preventive maintenance
i)Running Maintenance
ii) Shutdown maintenance
Corrective Maintenance
i)Breakdown Maintenance
ii)Shutdown Maintenance

Preventive maintenance
“Prevention is better than cure”
Preventive maintenance makes use of human senses like noticing unusual sound or
sensitive equipment like pressure and temperature or smoke gauges to predict the
problems before equipment fails.
i) Running Maintenance: The maintenance work which can be carried out when the
machine is in service, like replacing a part before it breaks etc,
ii) Shutdown Maintenance: The maintenance work which can be carried out when
the machine is not in service.
Advantages of Preventive Maintenance:
 The possibility of major break down is minimized
 Optimum production efficiency is maintained
 Life time of machine tools are improved
 Safety and working conditions are improved
 Availability of machine tools is ensured.
 Value of machine tools are maintained
 Operational accuracy is improved.
Limitations of Preventive maintenance:
 Accurate and reliable prediction techniques are needed
 Proper plan and maintenance teams are needed

Corrective maintenance
i)Breakdown Maintenance:
 The maintenance work which is carried out after a fault occur, like when a electric
motor does not work, etc.
 Once the fault is rectified maintenance is carried out only after next fault occurs.
Common reasons for equipment breakdown are:
 Not replacing worn out parts at right time
 In adequate lubrication or cooling
 Climatic conditions
 Improper handling
 Neglecting unusual sounds
Limitations of break down maintenance:
 Loss of production time
 May involve accidents and injuries
 Cannot be adopted for items regulated by safety norms like crane, lifts etc.
 Involves profit loss
ii) Shutdown Maintenance: T
 The complete overhaul of machines or equipment's after failure has happened.

References:
1. Hajra choudary, Media promoters and Publishers Pvt. Ltd, 2002.