AGMA 05FTM20-2005 pdf free.Dual Drive Conveyor Speed Reducer Failure Analysis.
The failure investigator must be like a detective and gather as much evidence as possible to determine the root cause of the failures. Failed reducers were returned to the manufacturer for analysis. The reducers were photographed and bearing setting measurements recorded before disassembly. Each component of the reducer was carefully inspected, removed and their appearance documented. Housings dimensions were checked on a CMM machine and verified against drawing specifications. Damage to the rotating elements was in varied degrees of distress. A common thread was the appearance of the low speed pinions. The pinions were severely spalled which can be attributed to either high loads or inadequate lubrication. Some of the low speed pinions also had broken teeth. Component ratings predict the low speed pinion as the limiting component in the reducer. Also, material removed from the pinions during operation caused debris damage to other components.
The OEM claimed that current readings were below nameplate full load rating and that the drives were lightly loaded. The OEM also claimed that the current between pimary and secondary drives was balanced by normal standards. Since the information supplied by the OEM did not agree with the analysis of the failed drives, further investigation was required to help with determining the root cause. A site visit was scheduled and an independent testing service was hired to measure loads. While the cost of load testing may appear to be high, it will often result in a lower total cost by enabling the investigator to determine the failures root cause faster than other analysis methods. The point at when to perform load testing is based on the experience of the investigator.Before going to the site, it is best to get as many questions answered as possible. This will help the investigator prepare for the trip and may provide an area of focus. Having questions answered before hand will also save valuable time at the site. Typical questions include:
What is the duty cyde?
Is the conveyor started loaded or unloaded?
How many times has it started loaded?
Are there operations records?
How many starts per day?
What is the starting procedure?
What type of controls are used?
What are the typical operating conditions (fully loaded, shock, etc)?
Has there been a report of any abnormal operating conditions?
What is the maintenance schedule and are there records?
Is it a new application or a retrofit into used equipment?
Along with other questions dependant on the situation.AGMA 05FTM20 pdf free download.