Problem: A fabricator of pressure vessels was breaking gearboxes, chains, and drive shafts on their trunnion welders. The customer is building pressure vessels that could be up to 8 feet round, 30 feet long and weigh up to 40 tons. The 4 foot long sections of tubes are welded to each other in a rotary weld using a trunnion welder that turns at a low RPM. The trunnion welder consists of 4 tires; a main inline gearbox runs a chain drive to the first gearbox (double input right angle gearbox) that is direct drive to the tire, then the other input has a jack shaft that connects to another gearbox that runs the second tire. The other two tires are idlers. The weight of the vessels would cause the gearboxes to overload and either break the jack shaft, or the gearboxes. The gearboxes are all custom gearboxes from the manufacturer of the trunnion welder. If a failure happened, the vessel would have to be removed and the trunnion welder would have to be repaired.
Solution: After many attempts at finding a standard gearbox to replace the current gearboxes at a lower cost, the BHQ Solution Provider decided to offer a total redesign using a HERA (High Efficiency Right Angle) gearbox for each trunnion making each trunnion run independently. The salesman also increased the torque rating by 5 times.
Benefit and Cost Savings: The new HERA gearbox is 40% more efficient than the old worm gearbox, the HERA gearbox has 5 times the torque rating, and the gearboxes are independent, decreasing the number of parts that could break. The old style gearboxes broke weekly and were not efficient. The customer should save over $250K a year by making the switch.