Maintaining that position led Jack Fairchild Jr., the company’s vice president of sales, to the decision that it was time to move from DC technology to AC technology. Making the change would require a major investment for the company, but Fairchild was determined to be the first to launch an AC battery-powered scoop.
“In this industry, if you want to remain successful, you have to stay ahead of the game,” Fairchild said. “We also felt strongly that AC technology provides so many advantages that making the investment would be worth the risk. This is the technology for the future and is the best way for us to take our product line to the next level.”
Fairchild believed the key to the project’s success was to build the right team. At the beginning of the project in 2008, Fairchild brought together his employees to discuss who they should partner with. They wanted to work with companies that had engineering and technical knowledge, good communications skills and the willingness to be a member of a team. As a result, Fairchild chose EnerSys for the battery, Magnatek for the drive and Baldor for the motors and gearbox.
“We chose Baldor because of our long relationship with the company, and the confidence and trust we have in its employees,” Fairchild said. “There was really no doubt Baldor was the company I wanted for this project because the people are top-notch and true professionals.”
Engineering New Products
Baldor engineers Nick Marsh, strategic account executive for the mining industry, and John Clark, senior customer order engineer for specialty gearing, led the design team effort for product development. With Baldor’s history in the mining industry and experience in moving from DC to AC technology in other projects, both engineers were confident they were up to the technical challenge. However, according to Marsh, the hardest and most critical part of the project comes at the very beginning.
“It’s our job to take the time to ask all of the right questions up front so we can get detailed specifications,” Marsh said. “In this case, we helped the Fairchild team think through the machine and the application so we could address all of the possible issues and requirements. It’s critical to get a clear understanding of their requirements and expectations, so we can design and build the exact product they need.”
From a motor perspective, that means detailing the exact torque and speed requirements. And because the motor would be controlled with a variable frequency drive (VFD), the Baldor team worked closely with the drive manufacturer to optimize performance. According to Marsh, the traction motor developed for Fairchild is based on the Baldor•Reliance RPM AC motor design with a good many enhancements.
“We optimized the pole design to meet the torque and speed requirements,” Marsh said. “This motor is MSHA explosion-proof approved, and we added a robust sealing system so it can more than handle the underground environment. And, as requested by the customer, we also added a feedback device for better speed control.”
With motor specifications in hand, the gearing team began its design work by starting with an existing gearbox base and then building from there. Engineers created a new gear ratio to meet Fairchild’s exact needs for torque and speed, building a box with new gears and bearings strong enough to handle the force. For Clark, the bigger design challenges came from some special requests by Fairchild.
“The company wanted us to design the gearbox so it could be used on either side of its dual tram scoop,” Clark said. “This universal design means they only need to stock one gearbox because it is interchangeable. A box that can be flipped gives them the flexibility they need to manage their inventory.” One other feature Fairchild wanted was a self-contained brake directly mounted on the gearbox. In the past, Clark explains, brakes were mounted with brackets hanging off the side of the box and taking up a great deal of space.
“To accommodate this request, we created new patterns and new castings for the top of the gearbox,” Clark said. “This was a great idea because now that the brake is a part of the gearbox, it’s more secure and provides much better performance.”
Because this was a new design, the project team attached special instrumentation on the box to capture data, while Fairchild ran the completed unit under test at its facility. Clark said the data was critical for him to understand what the gearbox was doing and how it performed under test. However, Clark was not content with just collecting and studying data. “I visited Fairchild after the test was finished and tore the gearbox down so I could examine and evaluate it myself. I looked at the gear patterns to make sure there were no issues, and I did the same thing with the bearings—making sure there was no