Due to frequent breakdowns of the gear spindle pair, a Hot Strip Mill in India experienced a huge loss of productivity and an increase in maintenance costs. The breakdowns caused damage to many elements of the gear coupling, including: The end rings running in contact with the flex-hub, excessive wear at the gear teeth, cracked sleeves, and end plate bolt failure. However, an initial observation of the damaged parts and even the installed spindle would not reveal the root cause.
Perceptiv™ Services Solution
The Perceptiv team studied the spindle in operation and at the repair bay over four visits. A detailed analysis was done using mill layouts provided by the customer to calculate the distance from a reference point on the mill stand to the thrust button on the pinion stand. A comparison of that calculated distance versus actual field measurement lead to identifying the root cause. The measured distance was fairly larger than the calculated distance.
Based on this clue, the Perceptiv team later observed a flaw in the work roll change procedure. The roll sleeve was being pushed by the workroll during installation leading to permanent deformation of parts, including the thrust plate at the pinion end. This would result in increased distances, leading to loss of designed gap between the flex-hub and the end ring. When the flex-hub was operated with inadequate gap, it would lead to the locking up of the gear pair, resulting in premature wear and damage to the gear spindle elements.
The Perceptiv team provided recommendations to properly align the work roll so that it does not push the spindle sleeve excessively during the work roll change. With the knowledge and support of the steel mill personnel, the Perceptiv team could solve a critical issue for the customer, saving thousands of dollars in lost production as well as maintenance costs.
Engineering Solutions For Mechanical Power Transmission Products
|Diagnostics||Tools and techniques used to measure the performance
of a customer’s application (determine the
root cause of performance problems, measure the
effects of product changes, establish a product
/ application base and confirm expected product
• Validation before and after performance
• Asset Management Program
• R&D / Testing.
|Education||Technical mechanical power transmission product,
process and application training for customers
|• eLearning training curriculum
• Customer location training sessions
• Off-site training sessions
• Factory based training sessions
|Design||Assist customers in reviewing application needs
and help select the appropriate products
|• Product selection assistance
• Product licensing
• Custom product design
• Certified layouts
• BOM: Complete list of required
products and accessories
|Installation||Installation and startup of mechanical power
|• Can provide a project manager, general
contractor or consultant for the installation
as well as additional labor.
|Monitoring|| Experts will teach customers how to use or install
monitoring equipment to measure the health of
products. Helps the customer transition from
reactive maintenance to a predictive maintenance
| • Electrical power consumption monitoring
• Mechanical torque / power monitoring
• Thermal imaging monitoring
• Ultrasonic measurement monitoring
|Repair|| Repair, rebuild or refurbish damaged or worn
power transmission products
| • Repaired / refurbished products come
with a factory warranty at a fraction of
the price of a new product