A failed Falk gear reducer can teach plant managers and maintenance technicians oodles about how to improve industrial operations. Understanding why a Falk gearbox failed helps engineers prevent future failures. Increased safety, efficiency and performance can also stem from failure analysis, as can reduced costs and environmental impact. The complexity of modern industry requires that certain steps be followed while conducting a thorough failure examination.
The first thing to do is to identify a team leader. This individual must have a broad understanding of failure analysis; excellent communication skills; and enough organizational power to identify the project’s scope. For instance, when examining why certain surplus gear reducers failed, the team leader must be able to understand which financial and chronological resources are available for the failure analysis. Once the team leader is in place, the following steps should be followed:
1. Assemble Your Team
The team leader should create an investigation plan that outlines what will be done as part of the failure analysis. The investigation plan should also explain why each task is important. Finally, this written strategy should clearly state investigation goals, so all parties grasp what they are expected to accomplish. T
The team leader will, of course, determine team staffing as well. Typically, the failure analysis crew should include tribologists (mechanical engineers who study interacting surfaces in motion), metallurgists and gear failure analysts. The gear analyst is the keystone; he or she must understand metallurgy, tribology, gear manufacturing and design, stress analysis and (obviously) how gears function and why they fail.
2. Gather Resources
To protect industrial parts, including surplus gear reducers, it’s best to shut down a malfunctioning part as soon as possible. Quarantine the failed Falk gearbox or other part so employees do not disturb or alter evidence. Preserve the location of the gearbox failure as a detective would preserve a crime scene.
So as to fully understand why a Falk gear reducer or other component seized up, failure analysts must have access to a variety of data, including:
- Background information, such as gearbox service history, manufacturer’s specifications, lubricant analysis and load data.
- Information gathered from visual inspection.
- Sound, temperature and vibration data.
- Gear tooth contact patterns with different load levels, if there’s evidence of misalignment but gears are still turning.
- Endplay and radial movement of relevant shafts.
- Gear backlash information.
To ensure that budget and time constraints are met, the team leader must be constantly checking in with team members. The team leader can also serve as the collector of the data that the failure analyst, metallurgist and tribologists need to do their jobs.
3. Gearbox Removal
Oftentimes, plants do not have enough space to disassemble gearboxes, so a failed Falk gearbox or other part must be transported to a gear manufacturing facility. Two overhead cranes are needed to take apart large gearboxes, to give you a sense of scale.
Don’t rush to remove the gearbox, however; make sure the analyst has time to record data such as the condition of keyways and seals. Otherwise, it will be nearly impossible to determine when such parts were damaged. Prior to cleaning the gear housing, look for signs of contamination, corrosion, overheating and oil leaks. You should also measure shaft alignment and look for clues of loosened fasteners.
4. Disassembling the Gearbox
Once the failed component is located in a well-lit, fully equipped location, it’s time for technicians to aid failure analysts in taking apart the system. This process should be carried out very slowly, so there’s time to compare each removed section to gearbox drawings and other plans. At this point, the idea is to gather data, not jump to conclusions.
Careful documentation is key; write everything down, take plenty of photographs, and go slowly so that you don’t miss any important evidence. Don’t forget to check the bottom of the Falk gearbox – oftentimes, broken gear teeth fall to the bottom.
5. Determining the Cause of Failure
To keep the scope of this article to a layperson’s level, let’s just say that the failure analyst will use gear geometry data, various tests and all previously mentioned information to figure out why the gearbox failed. Analysts use an approach like that of Sherlock Holmes; they eliminate the impossible until the truth emerges.
6. Report Findings
Finally, the team members will create a comprehensive report to communicate their findings and meet the goals of the failure analysis project.
Posted under Articles, Machinery Maintenance on Wednesday, February 22nd, 2012