10 Tips for Using Couplings in your Application
Couplings are some of the critical power transmission components in industrial and commercial settings. To get it right on couplings, it is important to ensure that you ask the right questions before picking the preferred option. This post brings you the top 10 tips for using couplings in your applications to enjoy high productivity.
Avoid Selecting Couplings Based on Price or Habit Only
Well, it is right to say that engineers are creatures of habit. Therefore, selecting a coupling type in many cases is only a matter of picking the type similar to the one you were using previously. But it is important to note that all couplings are not designed equally. This implies that specifying the couplings based on familiarity could result in mismatches.
Another common cause of errors when selecting couplings is basing the choice on cost. If you pick the coupling based on affordability as opposed to optimizing performance, there is a risk of the system being wrecked.
If you rely on familiarity, the chances are that you could pick the model that is too large or too small. To be able to pick the ideal option for your system, it is important to ensure that the loads, forces, and nature of shafts are understood.
Establish the Best Way for Mounting the Couplings
How you mount a coupling on a shaft could determine its success or failure even if you have selected the right model. If you have unidirectional models that have minimal shocks, it is advisable to go for the traditional keys, taper bushings, and keyways. However, those with reversing loads applications should consider keyless locking devices because they are backlash-free.
Answer the Question: What will the Coupling do?
The moment you decide to install an industrial system and establish that some couplings will be needed, it is important to ask one crucial question; what will the couplings do? But this is just one! You also need to establish other important aspects of coupling operations such as:
- Will the coupling transmit low or high torque?
- Will the application be high or low speed?
- What about the backlash?
- What is the load capacity of the application?
Getting the right answers to these questions will make it easy for you to crosscheck against different couplings on offer in the market.
Your Coupling must be Properly Installed for Proper Performance
For many people, picking the right coupling can be complicated. However, it need not be. The best approach is using the design criteria. This means focusing on torque, stiffness, shaft misalignment, inertia, rpm, shaft mountings, and space needs.
But picking the right coupling does not mean that you have completed the task. You need to have it installed. Even if the coupling is the correct one, installing it incorrectly can cause the entire system to malfunction and pull down its efficiency.
To install the coupling well, you need to strictly follow the manufacturer’s recommended procedure. It is also advisable to have a qualified person to do the job for better results. Note that even after installation; you will still need to maintain the coupling in top condition for proper performance.
Stay Away From Common Coupling Pitfalls
Just like other mechanical devices, your system's couplings should match the intended goal and application parameters. But designers need to go beyond this criterion to ensure they address problems like the speed of replacement, serviceability, and application environment if required. This is important to ensure that the downtime of your application remains minimal. Some common pitfalls include failing to understand what the manufacturer's specifications mean. For example, most manufacturers give the axial load data under ideal conditions. Therefore, applying them as they are could easily make your system to express an "error mode".
Understand the Right Terminologies
Is it inch-ounces or inch–pounds? Though these terms for expressing a coupling's torque could look obvious, they can be confusing to many people. If you get the coupling's specs wrong, your coupling might fail, underperform or damage your system. Another confusing term is keyways. Keyways are used for high torque couplings as opposed to high precision. If your application needs reversing torques and precise positioning, keyways will not be appropriate.
Check for Over or Underrating
Overrated couplings: This means that a flexible shaft coupling that you selected has a torque rating more than your system requirement
Underrated coupling: This implies a coupling with a torque rate that is insufficient for the application under consideration
The target should be identifying the coupling that ideally matches your system needs.
Wrong Selecting Means Wrong Type and Size
One of the common mistakes that engineers make is picking the wrong size and type of coupling. Though there are many types of couplings in the market that could work well in your system, it is important to appreciate that there are also others that will not. Therefore, it is prudent to understand the application needs and ensure to strike the right balance against the functional benefits of the couplings in the market to be able to pick the ideal option. For example, you need to factor things such as stiffness, temperature capability, speed capability, inherent balance, and brake loads among other components.
Look Out for Inadequate Torsional Stiffness
If a coupling lacks ample torsional stiffness, it is likely to cause resonance and failure. The problem has become common because machines are needed to stimulate cam profiles that create torsional vibrations. This results in excess noise, more vibrations, and ultimate failure. Therefore, it is prudent to ensure that the selected couplings have the right torsional stiffness before placing your order.
Factor Supplier Sizing Strategies and Shaft Assemblies
In many cases, people are tempted to match coupling torque rating to RMS info offered by the servo sizing software. However, this usually omits the torque spikes that occur because of load inertia changes. To address this problem, manufacturers have their formulas that also account for inertia. You need to check for this info to ensure that the coupling will have the right torque rating. It is also important to work with supplier application engineers for advice on properties such as inertia, critical speed, and flexibility among others.
If you want your system’s couplings to operate well and support high productivity, it is important to ensure that only the right ones are selected based on your system. Make sure to use the above ten tips to help get more value from your couplings.