Mechanical Troubleshooting: Chapter 1
Introduction to Mechanical Troubleshooting
In this module, we will learn about the importance of troubleshooting mechanical systems. We’ll also learn about steps to troubleshoot these systems. Skip to quiz!
Troubleshooting
Mechanical systems consist of simple mechanisms to create complex machines. Simpler mechanical systems are levers, pulleys, screws, wheels, and axles. In comparison, some more complex systems are pumps, valves, and fans.
Mechanical failure is likely to occur in a mechanical system, be it a simple or complex machine.
Machine failures are classified into:
Sudden failures,
Intermittent failures, and
Gradual failures.
A sudden failure is an unexpected breakdown in machinery. An example of this is a melted wire due to overheating.
Intermittent failures come and go, usually on their way to a complete machine failure. Think of a flickering light in your home. It will keep flickering for a few days, and then quit.
A gradual failure reduces the performance of a machine over time.
These include things like:
Slowly shedding of a belt,
Dulling of a pipe, and
Pipes that eventually clog with residue buildup
The common signs of failure in mechanical components are:
An increase in vibrations,
Excessive component heating, and
Leaky joints.
Aside from non-typical vibration and heating, other failure indications are:
Clogged pipes,
Corroded pipes,
Burning smells, and
Abnormal sounds.
The failure of a machine component can cause business interruption. For example, an unplanned machine failure could shut down an entire production line. This is because a business has to remain closed until repairs or replacement of its equipment can take place. During a business interruption, other equipment and resources like rent, wages, and salaries still have to be paid. This makes it necessary to troubleshoot any failure that occurs in a system as soon as possible
Troubleshooting is a method of finding the cause of a problem and correcting it. The ultimate goal of troubleshooting is to get equipment back into service as quickly and as thoroughly as possible.
Troubleshooting is the identification and resolution of problems, especially problems of a technical nature. In comparison, a repair is fixing the damaged condition of equipment. Think of a punctured tire. During troubleshooting, we find the exact location of the puncture and solve the problem. Repair is the process of fixing the hole in the tire. During a repair, we know exactly what is wrong with the equipment and how to solve the problem.
A troubleshooting technician must have the following skills to troubleshoot a problem:
A good understanding of a system's workings,
Attention to detail so they can spot the slightest errors in equipment,
Understand everybody’s interests,
Communicate decisions, and
Technical skills and experience.
Technical knowledge and experience helps in improving troubleshooting skills. Apart from technical knowledge, troubleshooters need to know the cause of mechanical failure. This will help to reduce future failures of a machine.
Common causes of mechanical failures are:
Not reading the operator's manual,
Improper maintenance, and
Overrunning machines.
Constantly pushing machines to run at maximum performance can strain joints and machine failure is more likely to occur. That’s why proper maintenance of machines is necessary.
For example, it’s essential to lubricate all moving parts periodically. Mechanical failures can also occur because of:
Not replacing worn parts,
Ignoring warning signals,
Improper storage,
Component misalignment, and
Poor electrical connections.
We can avoid these mechanical failures if the operator performs proper maintenance on a system.
Diagnosing a Problem
If machine failure occurs because of improper maintenance, the troubleshooter needs to diagnose the problem. The troubleshooter needs to ensure that the problem is rectified and does not mask another issue, which could repeat the breakdown.
The five basic steps required to troubleshoot equipment are:
Verify a problem exists,
Narrow down the problem’s root cause,
Correcting the cause,
Verify the problem is corrected, and
Prevent future issues by following up.
Let’s learn about each step in detail.
The troubleshooting process begins with symptom recognition. A symptom of poor wheel alignment is a car pulling to one side. During this step, the troubleshooter should note all abnormal symptoms and evaluate what’s observed.
The second step of the troubleshooting process heavily relies on the troubleshooter’s technical skills and experience. The troubleshooter is responsible for narrowing down the root cause of the problem.
For example, some refrigerator models have diagnostic test modes to detect the cause of a problem. This test mode allows us to diagnose a malfunction inside a refrigerator. This method helps us to narrow down the cause of a problem.
The third step involves rectifying the problem by performing equipment repair. In this step, the troubleshooter has to ensure that the equipment is ready to use.
Next, we need to test the component to verify if the problem is eliminated. This is always done before the machinery is returned to active service. The purpose of this is to prove that the issue no longer exists.
The fifth and final step in troubleshooting is the follow-up that will limit and prevent future issues. Actions may include:
Altering the preventive maintenance schedule, and
Recommending procedure modifications for more dependable performance
General Safety
While performing troubleshooting, we always need to wear the proper Personal Protective Equipment (PPE). A lack of PPE leads to many injuries in workplaces. For example, wearing gloves while using a portable grinder or buffing wheel can save you from a sharp cutting blade.
While troubleshooting, we should wear the following safety gear:
Safety glasses,
Gloves,
Safety-toed shoes, and
Hard hats.
We also need to remove all jewelry that could be caught in moving machinery.
We need to use the proper tools for a job while troubleshooting equipment to avoid injury. We also need to make sure lubricants are correctly labeled and stored. Improper labeling and storage can lead to contamination and the use of the wrong lubricant.
Mechanical failure is likely to occur in a mechanical system, whether a simple or complex machine. During business interruption, the cost of other equipment and resources still has to be paid. This makes it necessary to troubleshoot any failure that occurs in a system.
The five basic steps required to troubleshoot equipment are:
Verify a problem exists,
Narrow down the problem’s root cause,
Correcting the cause,
Verify the problem is corrected, and
Prevent future issues by following up.
The following safety gear is important to wear while troubleshooting to protect ourselves from harm:
Safety glasses,
Gloves,
Hard hats, and
Safety-toed shoes.
General Mechanical Troubleshooting
In this module, we will learn about common failures of mechanical systems. We’ll also learn about how to troubleshoot these failures. Skip to quiz!
Common Failures
Recall that common failures in a
mechanical system are:
Corrosion,
Pipe clogs,
Leaky joints,
Wear,
Vibration and noise,
Lubrication failure, and
Overheating.
Let’s go over each of these in detail.
Corrosion
Corrosion occurs when metals are exposed to moisture and oxygen. Recall that all mechanical systems, from a simple lever to complex valves, are made of metals. When these systems are exposed to moisture and oxygen, iron and steel will react, forming an oxide.
Recall that peeling paint damages our home walls. Similarly, oxide formation results in the flaking off of material from a metal surface, leading to cavity formation. Cavity formation is similar to cavities in our teeth. Like germs that eat into our teeth, oxygen in the air flakes off metals and forms a cavity. If corrosion is not prevented, it can cause the failure of a mechanical system. Corrosion of vital industrial parts, like couplings and gearboxes, is one of the most common causes of equipment failure. That’s why we need to troubleshoot rust formation on these components. Let’s watch a video that shows how to remove rust from machines
As seen in the video, it’s easy to locate rust, as it can be visually detected. After locating rust, we need to spray WD-40 over the rusted surface and wipe off the rust using a pad. If that does not remove the rust, we can use sandpaper.
To prevent rust from getting on a surface again, we should cover it using protective coatings. Just like brushing our teeth protects germs formation, the paint on metal surfaces protects corrosion.
We can apply anti-corrosive coats like inorganic paints on a surface.
Pipe Clogs
Apart from machines, corrosion is most likely to occur in pipes. This is because water or moisture inside a pipe reacts with steel to form iron oxide. The amount of iron rust deposits generated has the potential to clog a pipe.
Food and substances that do not break down will build up in our pipes because of clogging.
We need to remove all pipe fittings and check water flow to detect a pipe clog. If water is not flowing through a particular section of pipe, it indicates a clog. Calcium, Lime, and Rust Remover (CLR) solution clear almost all household clogged or sluggish drains in seconds.
Leaky Joints
Recall that corrosion eats away our pipe material. This can create openings for water to leak out. Leakage can also result from damaged watertight seals on our pipes. These seals can degrade over time, causing leaks at their source. This leakage is easily identified by dribbling water.
If a leak exists in a plumbing joint, the usual solution is to tighten that joint. But when the problem is found on the pipe itself, usually there is a need to remove the leaking section and replace it with a new one.
Let’s watch a video that shows how to troubleshoot pipe leaks.
As seen in the video, we need to apply a suitable solution around the portion where the leak is found. We can also remove the leaking section and replace it with couplings.
Wear
Another common machine failure is due to wear of the material. Wear is a failure mode that occurs due to materials rubbing against each other. For example, a pipe resting on pipe support rubs against the support every time the pipe moves.
Wear can be easily located visually. We can eliminate the cause of pipe erosion due to wear by inserting a pipe wear pad between a pipe and a pipe support. Since pipe wear pads are softer than a pipe's metal, the pipe pad wears instead of the pipe. We can also lubricate the moving components in a machine to prevent wear.
Vibration and Noise
As machine components like ball or roller bearings, drive belts, or gears become worn, they may cause vibration. Vibration can also result when machine shafts are not aligned with a machine axis.
If a machine is vibrating, it makes unusual sounds. For example, if the axes of a motor and pump are not aligned, we can hear disturbing sounds. To troubleshoot the issue of vibration and sound, we need to align the axes by shifting the machine.
We can also prevent vibration by reducing the wear of machine components. Recall that wear can be reduced by lubricating moving components.
Lubrication
Lubrication reduces friction and allows moving machine parts to slide smoothly past each other. Lubrication also helps in:
Cooling by dissipating heat from surfaces, and
Cleaning by transporting contaminating particles to filters.
The two main classes of lubricants that are used in machinery are:
Lubricants need to be applied in an exact amount. This is because under-lubrication risks metal-to-metal contact. In comparison, over-lubrication causes heat build-up and friction as the moving parts continuously push extra grease out of the way.
Overheating
Overheating can also be caused if a machine is running in a much warmer environment. This is because outside temperatures make it more difficult for a machine to cool down properly.
The most likely causes of overheating are:
Blocked ventilation holes,
Using less capacity motor for the application, and
High ambient temperatures.
We need to clean a machine and operate it in the temperature range recommended by its manufacturer.
The common failures in a mechanical system are:
Corrosion,
Pipe clogs,
Leaky joints,
Wear,
Vibration and noise,
Lubrication failure, and
Overheating.
We need to fix these common failures to avoid total system failure. Anti-corrosive coats can prevent corrosion. Lubrication reduces friction and allows moving machine parts to slide smoothly past each other. Wear can be reduced by lubricating moving components, which will help reduce vibrations and noise.
Question #1: What are the types of machine failure? (Select all that apply)
Intermittent failure
Sudden failure
Seasonal failure
Gradual failure
Scroll down for the answer...
Answer: Intermittent failure
Sudden failure
Gradual failure
Machine failures are classified into:
Sudden failure,
Intermittent failure, and
Gradual failure.
Question #2 : What are common signs of mechanical failure? (select all that apply)
Burning smells
Abnormal sounds
Excessive component heating
An increase in vibrations
Scroll down for the answer.....
Answers...
Burning smells
Abnormal sounds
Excessive component heating
An increase in vibrations
The most common signs of failure in mechanical components are:
An increase in vibrations,
Excessive component heating,
Burning smells, and
Abnormal sounds.
Question #3: What is troubleshooting?
Fixing the damaged condition
Both identification and resolution of problems
Only identification of problem
Only resolution of problem
Scroll down for the answer.....
Answer: Both identification and resolution of problems
Troubleshooting is the identification and resolution of problems, especially problems of a technical nature.
Question#4 : What causes mechanical failure? (select all that apply)
Periodic maintenance
Overrunning machines
Component misalignment
Ignoring warning signals
Scroll down for the answer.....
Answer: Overrunning machines
Component misalignment
Ignoring warning signals
Common causes of mechanical failures are:
Component misalignment,
Ignoring warning signals,
Improper maintenance, and
Overrunning machines.
Question #5: What is the first step to begin mechanical troubleshooting? (select all that apply)
1. Altering maintenance schedule
2. Replacing the machine
3. Verifying the problem and its symptoms
4. Lockout tagout
Scroll down for the answer.....
Answer: Verifying the problem and its symptoms
The troubleshooting process begins with symptom recognition
Question #6: Which safety gear should we wear while troubleshooting to prevent injury? (select all that apply)
1. Safety shoes
2. Safety glasses
3. Gloves
4. Face or respiratory masks
Scroll down for the answer.....
Answer : Safety shoes
Safety glasses
Gloves
While troubleshooting, we should wear the following safety gear:
Safety glasses,
Gloves,
Hard hats, and
Safety-toed shoes.
Question #7 : How can corrosion lead to machine failure?
1. It causes heat build-up and friction
2. It allows machine parts to slide smooth
3. ly past each other
4. It causes the flaking off of material from a metal surface
5. It results in machine vibration
Scroll down for the answer.....
Answer : It causes the flaking off of material from a metal surface
Corrosion causes oxide formation on a metal surface.
This results in the flaking off of material from a metal surface, leading to cavity formation.
Question #8: What is the cause of pipe clogs when water is running through a pipe?
1. Looseness
2. Misalignment
3. Corrosion
4. Overheating
Scroll down for the answer.....
Answer : Corrosion
The amount of iron rust deposits generated due to corrosion has the potential to clog a pipe.
Question #9: What is a possible cause of water leakage in a mechanical system? (select all that apply)
1. Looseness
2. Misalignment
3. Corrosion
4. Damaged seals
Scroll down for the answer.....
Answer :Corrosion
Damaged seals
Corrosion eats away pipe material that can create openings for water to leak out.
Leakage can also result from damaged watertight seals on our pipes.
Question #10: Why does wear failure occur in a machine? (select all that apply)
1. Due to materials rubbing against each other
2. Because of looseness
3. Because of shaft misalignment
4. Due to blocked ventilation holes
Scroll down for the answer.....
Answer : Due to materials rubbing against each other
Wear is a failure mode that occurs due to materials rubbing against each other.
Question #11: What is the effect of vibration on a machine?
1. Improve machine cooling and ventilation
2. No metal-to-metal contact
3. The machine makes unusual sounds
4. Machine parts to slide smoothly past each other
Scroll down for the answer.....
Answer : The machine makes unusual sounds
If a machine is vibrating, it makes unusual sounds.
Question #12: What can cause overheating of a machine? (select all that apply)
1. High ambient temperatures
2. Blocked ventilation holes
3. Using less capacity motor for the application
4. High or low voltage supply
Scroll down for the answer.....
Answer : High ambient temperatures
Blocked ventilation holes
Using less capacity motor for the application
High or low voltage supply
The most likely problems causing overheating are:
Blocked ventilation holes,
Using less capacity motor for the application,
High or low voltage supply, and
High ambient temperatures.