GEARBOX FAILURE

In 2018, one of TNT MIS’ clients had a breakdown on one of their main lines on an uncoiler gearbox. This gearbox starts the coil on the finishing process. It takes a 40,000-pound coil and gets put on a mandrel before it is unwound. As it is unwinding, the machine is pulling the material off; it is feeding it through the machine and this gearbox regulates the rate with which it comes off. If they stop the line, there is a 24-inch-wide brake that keeps it from continuously rolling and uncoiling. That physical brake is on the gearbox itself and without it, the gearbox cannot run.

 

This particular gearbox was manufactured in 1972 and the manufacturer does not make this style any longer. Consequently, the client did not have a spare or a way to get a spare. The gearbox was completely destroyed on the inside and could not be repaired. The client has completed routine maintenance on it for almost 50 years, which is what a lot of plants do. They sent it out to two different machine shops for repair before being told it could not be repaired. Their third call was to Ryan Shade at TNT MIS asking for a new gearbox.

 

It was not possible to get anything quickly. Initially, the best solution was a 6-8 week lead time from Brazil, which would have likely taken 13 weeks. Ryan contacted a build center that keeps certain products in stock to quickly ship them. The build center did not have a gearbox that was a drop-in replacement, but they had one that was shorter. The old gear box had a 2.5-inch output shaft. The new gearbox had a 2-inch output shaft. The output shaft is special because it has an 18-inch extension on it, so it's 18 inches longer than normal.

 

By using the dimensions of the original gearbox, torque capabilities, and horsepower ratings, Ryan found another gearbox that would work with some modifications. He ordered the new gearbox and went to a machine shop in St. Louis, MO who already had the initial damaged gearbox. They broke the clutch on the initial gearbox and saw that everything inside the clutch is made for a 2.5-inch shaft. The new gearbox cannot be altered for a 2.5-inch shaft due to the seals. This brought up a new challenge requiring changing over all the parts in the clutch to a 2-inch shaft, making spacers, figuring out bearings to get different ones, and ordering all these parts to put this back together. The machine shop made the shaft and Ryan worked with them to get everything back together. An adapter plate was also created to bolt it into place since this new gearbox was shorter. In addition, there was special machining performed on the output shaft because there is special fluid that goes into the brake.

 

It took 4 days for Ryan to get the client up and running, substantially less time than the second option of 13 weeks. This company runs two lines, and this cut their production in half. They lost hundreds of thousands of dollars per day until the gear box could get up and running, which ended up costing them $16,000.

TNT MIS is your one-source solution for all power transmission, bearings and gearing, any type of conveyor or component, lightweight and heavyweight belting, repairs, and much more! With over 27 years of experience they are just waiting to solve your challenges. TNT MIS' direct line is ‪314.399.8864.

Success Stories