A ball screw failure can cause major issues that not only slow down production but also may put employees in danger. While there are many reasons that failure may occur, keep an eye out for these common ball screw problems that could impact your assembly.
What are the most common ball screw problems?
When a ball screw assembly is failing or underperforming, many different issues could be at play. However, these eight ball screw problems most commonly impact ball screw assemblies:
- Exceeding the dynamic or static load capacities. This will overstress the ball screw assembly and cause mechanical failure over time.
- A dirty environment and lack of protection or sealing.
- Poor lubrication or using an incorrect lubricant.
- Improper storage. This may create a rusty or dirty ball screw assembly.
- Specifying the incorrect screw. An application may require a stainless screw for corrosion protection, however load capacities drop with a softer material.
- Machine crash without proper inspection or replacement.
- Side loading of the ball nut on the ball screw caused by either improper machining or misalignment in the equipment.
- Exceeding the critical speed of the ball screw assembly.
What causes most ball screw problems?
Most of the above common ball screw problems and ball screw failures are caused by human error. This includes exceeding capacities, specifying incorrect screw for an application, and improper maintenance.
Other common ball screw problems, such as a dirty environment, can be caused by the work environment that the assembly is used in. While these problems usually will not cause a catastrophic mechanical failure, they can slow down machinery and play a part in causing ball screws to fail over time.
If a ball screw assembly is required to operate in a dirty work environment, it is possible to design and implement a screw that can withstand these conditions. This would avoid or limit the impact of problems caused by the challenging environment.
Which ball screw problems are the most serious?
If ignored, ball screw problems can lead to a catastrophic mechanical failure. This is the most serious concern for engineers to be aware of, as it may cause a machine to crash or free fall.
The most common ball screw problems that lead to a catastrophic failure include:
- Exceeding load capacity,
- Specifying the incorrect ball screw for the application, or
- A machine crash without proper inspection or repair.
What are the warning signs of ball screw failure?
There are several signs to be aware of that may signal an upcoming ball screw failure. They include:
- Strange noises, such as clicking or grinding
- Excessive backlash
- Binding when rotating
- Excessive heat
- Increased torque
If your ball screw assembly is showing any of these signs, it should be inspected immediately.
How can ball screw problems be prevented?
The most important thing to do to prevent a ball screw failure is to specify and implement the proper ball screw assembly for the application. This ensures that the load capacities are not exceeded. Choosing the correct screw from the beginning will help prevent a catastrophic failure.
The next step is to implement a proper maintenance plan and procedure. This will ensure that the ball screw is clean and properly lubricated. This maintenance process will prolong the life of the ball screw.
Choosing the correct ball screw manufacturer is just as important as specifying the correct ball screw for the assembly. Letting the experts guide you in choosing the correct style, grade and material for your ball screw assembly will help prevent a damaging catastrophic failure. PST can help you choose and manufacture the correct ball screw assembly for your application. Contact us today.