Gearbox Failure Analysis
A major part of the benefit that DCL Engineering can offer you is Failure Analysis. Tools which we utilise to correct inaccuracies, wear and failures will also tell us the likely cause of the failure which in turn allows us to suggest ways to minimise the chances of that failure in future. Several of these tools are described here.
Co-ordinate Measuring Machine (CMM)
The CMM used by DCL Engineering is the Platinum version of the Faro Arm, the world's most accurate and advanced portable measurement arm in manufacturing history. This is an advantage over any other company's methods of checking gearbox and component dimensional accuracy.
The Platinum FaroArm's ±0.05mm accuracy renders traditional CMMs, hand tools and other portable inspection equipment slow and inefficient.
Inspect, reverse engineer gear cases and components, or perform CAD-to-Part-analysis on parts, fixtures and assemblies with previously unheard of precision.
Carry out dimensional checks and on the spot quality control inspections of equipment.
Non-Destructive Testing (NDT) is a cost effective process for checking deterioration of items (scoring, unseen cracks) and is used to determining whether an item is fit for use and assists DCL in the following areas:
- Quality Assurance
- Ensuring Safety
- Failure Prevention
- Client Satisfaction
The advantage of NDT is that the item being tested remains in its original state unchanged and not destroyed. If no faults are found after testing, the item can continue to be used for its original intended purpose. DCL Engineering use several different forms of non-destructive testing to ensure soundness in the materials and components used in our gearbox refurbishment. The following detail out three methods used by DCL.
Fluorescent Magnetic Particle Testing
Magnetic particle testing is effective in finding surface deterioration on ferromagnetic (materials that can be magnetised) materials. Once the item is temporarily magnetised, fine iron particles are applied to the surface and will form along the lines of the magnetic force from the magnet. Flaws on the surface will cause the lines to be distorted and this method is best suited for detecting surface flaws.
Dye Penetrate Inspection
Dye Penetrate Inspection (DPI), also known as liquid penetrant inspection, is a common and low-cost method to detect surface cracks on non-porus materials (not having vessels that appear as pores). DPI can also be used on non-ferrous materials and is used to detect cracks, leaks, casting and forging defects. Liquid penetrant is applied to the surface and absorbed into defects by capillary action. After a period of time the penetrant is drawn out and a visual inspection is performed on defects.
DPI is used when Fluroescent Magnetic Particle Testing is impractical due to the size or shape of a component is by using a dye to see if it soaks into a surface crack. This is most often used on larger fabrications or castings, such as gearbox housings and large flanged couplings.
If a component is suspected of internal faults which don't show on the surface, such as some forgings, then the component can be x-rayed to determine the internal structural soundness prior to proceeding with the component.
Vibration analysis (VA)
Early Detection of Mechanical Wear and Breakdown
As bearings and components reach near the end of their usage vibrations get more dramatic, this indicates that it's time to schedule a repair or replacement of machinery to avoid unplanned expensive failures.
Gear tooth contact will cause vibration, as will the rotational action of the rolling elements within the bearings. All of these components have their own 'signature' and an expected frequency and amplitude at which they will vibrate. An analysis of this vibration when compared to the initial signatures will indicate the extent of wear in the components. This is a high level Science which is used to your advantage when DCL Engineering Group test your gearbox. You have a signature of the vibration levels present when the component was tested, and this can be compared with subsequent analysis conducted at a later date on site to determine the condition of each component within the gearbox.