ME495 Lab 06_ Vibration Analysis Lab

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Heat Plate Exchanger ME 495: Mechanical and Thermal Systems Lab Section 05: Thursday Group D Authors: Soeung Khanitha, Smith Emilee, Sichantha Jack, Taylor Charles Instructor: Dr. Hamid Nourollahi Thursday, February 15, 2024

1 Table of Contents ( Khanitha Soeung ) Objective of Experiment ( Jack Sichantha ) .............................................................................. 1 Equations and Symbols ( Khanitha Soeung & Jack Sichantha ) ........................................... 2 Equipment ( Khanitha Soeung ) ................................................................................................. 2 Experimental Procedure ( Khanitha Soeung ) .......................................................................... 3 Experimental Results (Charles Taylor) ...................................................................................... 6 Discussion of Results (Charles Taylor) ..................................................................................... 7 Lab Guide Questions (Emilee Smith) ......................................................................................... 9 Conclusion (Emilee Smith) ....................................................................................................... 10 References ( Khanitha Soeung ) .............................................................................................. 10 Appendix ( Khanitha Soeung ) .................................................................................................. 11 Table of Figures and Tables( Khanitha Soeung ) Figure 1: Vibration Analysis Unit (95-ME5 AI) ........................................................................... 2 Figure 2: Belt Drive Setup ........................................................................................................... 3 Figure 3: Belt Tension ................................................................................................................. 3 Figure 4: Sensor Placement ....................................................................................................... 6 Figure 5: Velocity of Vibrations for Motor ................................................................................. 7 Figure 6: Velocity of Vibrations for Bearing Support ............................................................... 7 Table 1: Lab Data ......................................................................................................................... 8 Objective of Experiment ( Jack Sichantha ) This lab experiment aims to introduce students to the 95-MEAI Vibration Analysis Learning System. This demonstrates the use of vibration analysis for maintaining power transmission components. Students will acquire practical skills such as using a vibration meter to measure vibration, identifying measurement points on various power transmission systems, analyzing the results, and minimizing the vibrations. Primarily this experiment will focus on using the vibration meter to monitor the condition of a belt drive, enabling a timely correction to prevent system failure. Both the horizontal and vertical readings are needed to detect any worn or . stretched belts. The axial readings will help identify belt or shave misalignments. The main

2 objective is to establish a correlation between vibration direction as well as the underlying effects. Velocity measurements are recommended due to the low rotational speeds of belt drives. When measuring the belt drive vibration, readings should be taken on the bearing nearest to the sheave, or if needed, on the motor, to ensure consistent sensor placement per measurement. The team states that, for the motor and bearing alike, the defective belt will cause more vibrations along the vertical and horizontal axes, while the sheave misalignment will likely increase the vibration velocity in the axial direction. Equations and Symbols ( Khanitha Soeung & Jack Sichantha ) No equations used throughout this experiment. Equipment ( Khanitha Soeung ) Figure 1: Vibration Analysis Unit (95-ME5 AI) ● Amatrol 95-ME5-AI Vibration Analysis ○ Analyzes Vibrations in machinery and equipment. ○ Detects and measures the amplitude, frequency, as well as imbalance, misalignment, or bearing wear as potential issues. ● Vistec Hand-held Vibration Meter ○ Used for on the spot vibration measurement and analysis. This tool provides real time readings of vibration levels. ● Assorted Wrenches

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3 ○ Basic tools used to tighten or loosen nuts & bolts during maintenance or repair task. These tools vary in size to accommodate different fastener types. ● Assorted Allen Wrenches ○ These tools are used for driving bolts & screws with hexagonal sockets. These are needed to access and tighten fasteners in small spaces. ● Extech 41893 Non-contact Digital Tachometer ○ This tool measures the rotational speed of machinery by using non-contact method, such as laser, to help monitor machinery performance or diagnose issues related to speed variations or any other abnormalities. Experimental Procedure ( Khanitha Soeung ) Figure 2: Belt Drive Setup Figure 3: Belt Tension Before the setup, all loose clothing was tucked in, watches, and jewelry were removed. Long hair was tied back and safety glasses were worn when the belt was in operation. The belt drive was installed & aligned using an 18 inch straight edge to ensure the alignment of the two

4 sheaves, while ensuring the zerk fitting on the pillow block bearing closest to the sheave faced away from the motor. An alignment check was performed by looking down the side of the machine to ensure alignment of the two sheaves. With adjustments made if needed by loosening the motor sheave, aligning it w/the bearing sheave by hand, and then retightening it. The belt tension was set to 3-4 lbs using a tension tester and a straight edge for reference. All nuts & bolts were securely fastened to prevent anything from coming loose during operation. The vibration meter was configured by obtaining it from the storage location. Installing the magnet to the accelerometer, pressing the ‘select’ button to turn it on, scrolling to select ‘ALL’ and ‘mm/s’ as the units, and holding the button until the reading stabilized around a constant number, which served as the recorded data. These steps ensured the safe and effective operation of the machinery. Baseline Directions The lockout tag-out, which was a lock guarding the ‘ON’ switch, was removed from the Amatrol device, and everyone was ensured to stand clear before starting the motor. The sensor of the vibration meter was placed on the motor to measure horizontal vibration, and a velocity (mm/s) reading was taken, ensuring that the sensor was parallel to the centerline of the two shafts as shown in Figure 4 of the lab guide provided by Dr. Hamid Nourollahi. Measurements were recorded on Table 2, with three runs conducted (n=3). This process was repeated for the sensor in an almost vertical position on the motor. Then conducted again for both horizontal and vertical positions on the bearing. An additional step involved converting the axial position (perpendicular) of the bearing by placing the vibration meter ‘ON’ the bearing pillow block, NOT the rotating sheave, with the measurement recorded on Table 2 as seen in the lab guide. RPM readings were recorded one time (n=1) each for the motor and bearing sheaves using the

5 non-contact digital tachometer, by holding it steady and parallel to the ground while pointing it at the reflective tape placed on each of the sheaves. The motor was then stopped, and the lockout/tagout was installed as it must be when adjusting the belt or the sheaves. Defective Belt A plastic zip tie was installed around the belt, and any excess tail was trimmed off using a pair of scissors. It was ensured that the knob of the zip tie was residing on top of the belt, avoiding the placement on the belt’s side to prevent excessive vibration. In the event that the zip tie snapped off the belt during operation, the belt drive was shut down, and then a new zip tie was installed, ensuring all safety procedures were followed. Parallel Misaligned Sheaves (with defective belt) A ruler was used to misalign the sheaves very slightly ( less than one inch ) following steps 3a and 3b in the lab guide. Ensuring they remained parallel it was ensured that the misaligned motor sheave was not overhung the end of the rotating axle nor was it pushed flush with the motor casting. Parallel Misaligned Sheaves The plastic tie was previously removed from the belt. Step 8b was repeated as instructed in the lab guide. Once the experiment was completed, the belt was then removed from the sheaves, all tools used were replaced, and the work area was cleaned up.

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6 Data Reduction Figure 4: Sensor Placement After completing all the readings, the data was graphed and compared to analyze the significance of the numbers obtained. Two separate graphs were created, one for the motor and one for the bearing. The independent variable, representing the belt condition (baseline, zip tie, zip tie w/misaligned, and misaligned), was plotted on the x-axis, while the dependent variable, represented the vibrations, was plotted on the y-axis. For each graph, bars were added for each direction measured. For instance, the bearing graph included bars for the x, y, and z direction. Upon comparing all the graphs, various patterns and trends were observed indicating the impact of different belt conditions on vibration levels. Detailed analysis was conducted to interpret these findings and understand the implications.

7 Experimental Results (Charles Taylor) Figure 5: Velocity of Vibrations for Motor Figure 6: Velocity of Vibrations for Bearing Support

8 Table 1: Lab Data NOTE: No sample calculations were needed for this experiment’s data reduction. All data analysis was done directly from the experimental results. Discussion of Results (Charles Taylor) Figure 5: Velocity of Vibrations for the Motor shows the magnitude of the vibrations in both horizontal (parallel with belt) and vertical (perpendicular to belt) planes for the motor. Four different sets of data were collected, one with a normal belt, one with a defect in the belt, one with a misaligned belt, and one with both a misalignment and a defect. The data indicates that the vertical and horizontal vibrations both saw a dramatic increase in magnitude in both tests with the defective belt. Both vibration directions increased by about 5 or 6 mm/s to compare data. As for the misalignment, this seemed to cause a slight increase in horizontal vibration, while causing a slight decrease in vertical vibration. Figure 6: Velocity of Vibrations for the Bearing Support shows the magnitude of the vibrations in the horizontal (parallel with belt), vertical (perpendicular to belt), and axial (out of

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9 the plane from belt) planes for the bearing. Four sets of data were collected, one with a normal belt, one with a defect in the belt, one with a misaligned belt, and one with both a misalignment and a defect. The data indicates that the vertical vibrations saw a dramatic increase in magnitude in both tests with the defective belt, increasing by about 7 mm/s to comparable trials. The defect also seemed to slightly increase the vibrations along the horizontal axis. The misalignment seemed to have little effect on either the vertical or horizontal vibrations. As for the axial vibration, the misalignment, surprisingly, caused a decrease in the vibration magnitude. The defect-only data showed a significantly higher axial vibration than any other data set. Using Table 1.A from the Lab guide handout for Vibration Analysis, we can see that any Vibration Velocity above 10.7 is considered severe. This means that, for the bearing and the motor, having a defective belt will make the system unsafe and severely vibrational. This said the baseline (no defect, properly aligned) for a majority of the data shown above indicates that the machine itself already operates at a level between 5.4mm/s and 10.7mm/s which is still a very rough and potentially damaging amount of vibration. The data shown above does not necessarily show a large indication of error, however, the axial loading data shown in Figure 2, indicates that some error may have occurred while measuring the vibration for the defect belt. Some sources of possible errors are human error, including misreading the vibration meter or not tightening the motor well enough. Some errors may also be systematic from the calibration of the machine or the vibration meter. These results generally conclude that the axial vibration is more of a product of the sheave misalignment, while the vertical and horizontal vibrations are more of a result of a defect in the belt. This partially confirms the hypothesis stated in the objective. The hypothesis stated that the defective belt would cause more vibrations along the vertical and horizontal axes, while the sheave misalignment would likely engender more vibration in the axial direction.

10 While the data suggest that the correlations between these directions of vibration and belt issue are true, the data inversely proves that misalignment causes additional vibration in the axial direction, instead it causes a decrease in vibration velocity along the axial loading. Lab Guide Questions (Emilee Smith) 1. What are some potential causes of belt drive vibration? The movement of the motor while it is running as well as the rotational speed can cause belt drive vibration. A deviation of vibration from the baseline can indicate a problem with either the motor, bearing, or belt, along with other parts of the system. Potential issues with misaligned shafts, an unbalanced system, bearings that have been worn down or overstretched, can all cause more or less belt drive vibration. 2. Why is it important to measure vibration on a belt drive? Explain each direction. Measuring the vibration on a belt drive regularly will allow for regular maintenance to prevent issues before the system fails. This regular measurement can be compared to overall velocity guidelines and will show whether the system is well aligned, has minor faults, or even whether it is unsafe to run altogether. Measuring in different directions can help to indicate where the problem is coming from and what might need to be checked or repaired. The readings taken vertically and horizontally can detect issues with the belt, such as wear or excessive stretching. The measurements of vibration in the axial direction that are taken on the bearing will show whether or not the belt of sheave is misaligned. 3. Which measurement direction yielded the highest vibrations on the motor? Explain. Overall, the highest vibrations on the motor were recorded in the horizontal direction. This is most likely because the system is set up along the x-axis and the belt is pulling in the horizontal direction.

11 4. Which measurement direction yielded the highest vibrations on the bearing? Explain. The bearing, on average, yielded the highest vibration readings in the vertical direction. This could potentially be due to the installation of the belt drive and the fittings holding down the sheave, putting a vertical force on it. 5. What are possible sources of error in your experiment? The baseline measurement wouldn’t necessarily provide readings that would be similar to a well balanced, well aligned system because it is used consistently for this experiment (unless routine maintenance is done). Other sources of error include the vibration recordings as they were usually in a range each time and a single number wasn’t always what was shown on the device, so the number it stayed near the longest was the number that was recorded. Finally, the added defect (the zip tie) may be put on differently by different people, possibly causing the vibration analysis to change slightly. However, with the baseline reading, it was possible to still see a trend in the data and what types of affects different defects or alignments might have on the vibration. 6. Are the vibration readings on the motor and the bearings what you expected? If not, what do you think the cause is? Most of the readings were as I would expect, higher vibration readings for the different circumstances. However, some readings were below or roughly the same as the baseline readings which was not what I was expecting. The cause for a slightly lower, or similar vibration result with a misaligned sheave makes sense now, because with the misalignment, the direction mostly affected is the axial direction. The readings for the motor were done vertically and horizontally. Conclusion (Emilee Smith) The main objective of the experiment was to become familiar with the process of vibration analysis for maintaining components of power transmission systems such as belt

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12 drives, sheaves, bearings, and other machine components. Measuring vibrations provides information on the functionality of a system and the technique can be used to determine what part of the system might need maintenance. The results of vibrational analysis can be compared to the guidelines for vibration severity to determine functionality - whether the belt, sheaves, or other various components of the system can be repaired or completely decommissioned. Per this experiment, a defective belt or misaligned sheaves with a belt defect can be determined easily by observing an increase in vibrational velocity on the bearing in the vertical direction. For misaligned sheaves, the vibration analysis left little deviation in all directions for both the motor and bearing measurements making it difficult to determine what direction the change in vibration velocity correlates to this system component. References ( Khanitha Soeung ) [1] Nourollahi, A. (2024). ME-495 Laboratory Exercise – Number 6 –Vibration Analysis In ME Dept, SDSU – Nourollahi. SDSU Publishing [2] Nourollahi, A. (2024). ME-495 Course Introduction_and Syllabus Spring 2024-1. In ME Dept, SDSU – Nourollahi. SDSU Publishing

13 Appendix ( Khanitha Soeung )