Topics: Chapter 1: Maintenance Chapter 2: Safety Mech 1200 Topics: Chapter 1: Maintenance Chapter 2: Safety Introduction to the Mechatronics Trainer Note: Refer to textbook Mechanical Principles and Systems for Industrial Maintenance, Richard Knotek and Jon Stenerson, Prentice Hall, 2006

Introduction Some types of maintenance techniques: Mech 1200 Introduction Some types of maintenance techniques: Preventative maintenance: Performing scheduled and unscheduled tasks on an equipment for optimization and preventing failure. Predictive maintenance: condition monitoring of an equipment in comparison to a preset standard or baseline. Proactive maintenance

Examples of Predictive maintenance Mech 1200 Examples of Predictive maintenance Vibration analysis: Analysis of the oscillatory motion in a cyclic manner. Oil Analysis: Investigation of the physical properties and presence of contaminants in oil samples. Thermography: Analysis of the temperature of an equipment at different operating conditions.

1. Vibration Analysis Resonance: magnification of vibration Mech 1200 1. Vibration Analysis Resonance: magnification of vibration Resonance occurs when the frequency of oscillation matches the natural frequency of the object. Based on rigidity. Critical speed: the speed at which the mechanical part resonates. Cycle Amplitude Frequency: cycles per second Phase: the position relative to a fixed point and time. Velocity and Acceleration

Mech 1200 1. Vibration Analysis Transducers Analyzers

Example 1: Vibration of two beams If two vibrating cantilevered beams had the following waveforms, answer the questions that follow: Mech 1200 Displacement (inch) 2 – 1 – 0 – -1 – -2 – | | | | | | | | | 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 Time (S) What is the frequency of the blue waveform? Solution: count the cycles between any 2 points where a transition from – to + occurs . There is only one cycle between the two x marks, and the time is 0.5- 0 = 0.5 seconds Thus, the frequency is 𝒇= 𝟏 𝒄𝒚𝒄𝒍𝒆 𝟎.𝟓 𝒔𝒆𝒄𝒐𝒏𝒅𝒔 =𝟐 𝒄𝒚𝒄𝒍𝒆𝒔 𝒔𝒆𝒄𝒐𝒏𝒅 =𝟐 𝑯𝒛 What is the frequency of the red waveform? For this wave, the frequency is 𝒇= 𝟏 𝒄𝒚𝒄𝒍𝒆 𝟐 𝒔𝒆𝒄𝒐𝒏𝒅𝒔 =𝟎.𝟓 𝒄𝒚𝒄𝒍𝒆𝒔 𝒔𝒆𝒄𝒐𝒏𝒅 =𝟎.𝟓 𝑯𝒛

Example 2: Vibration of two beams Mech 1200 Example 2: Vibration of two beams One beam started vibrating at a frequency f1. A while later, another beam started vibrating, the waveform graph of the two beams is shown below (assume no damping occurs): Displacement (inch) 2 – 1 – 0 – -1 – -2 – | | | | | | | | | 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 Time (S) Which waveform belongs to the first beam? What is the frequency of the blue waveform? What is the frequency of the red waveform? What is the phase difference between the two waves in seconds? What is the peak-to-peak amplitude of the vibration of the beams? The blue waveform 1.25 Hz 1.25 Hz 0.2 seconds About 4’’

Safety Procedures Accidents Accident Prevention Mech 1200 Safety Procedures Accidents Accident Prevention Lockout/Tagout Standard In effect since 1989 in the United States To control hazardous energy sources. Lockout: placement of a device that locks out the energy-isolating device. Tagout: placement of a tagout on the energy-isolating device.

12/2/2018 Lecture 1, Mechanical Components and Electric Motors, by Khalid H. Tantawi, MSCC

Lockout Sequence Notify all affected employees. Mech 1200 Lockout Sequence Notify all affected employees. Must identify the machine load/energy and any hazards associated with it. Shut down properly. Deactivate energy source. Lock out energy source. Dissipate any stored energy (ie capacitors). Ensure equipment is disconnected and won’t operate.

Mech 1200 Lockout Requirements Use a positive means to keep the energy-isolating device in the safe position. The lockout device must be able to withstand the environment it is exposed to, such as excessive heat, radiation, freezing..etc. The lockout and tagout devices must be standardized in the facility in size and/or color and/or shape. The lockout device must be strong enough to prevent removal without excessive force. Notification of employees before the application and after removal of the lockout/tagout. Only the employee who applied it can remove it.

Tagout Requirements Must contain a clear warning. For example: Danger. Mech 1200 Tagout Requirements Must contain a clear warning. For example: Danger. Must state clearly that moving the energy-isolating device from the safe mode is not allowed. Must be placed in the place a lock device would be placed, or if not possible, as close as safely possible in a position obvious to anyone who attempts to operate the device. Must be able to withstand the environment. Must be standardized in the facility. Must have a nonreusable type of attachment. For more Lockout/Tagout requirements, please read pages 27 and 28 of the text.