A Flowery Branch plant is getting the motor running for Tesla Motors, a producer of electric cars increasing in popularity.
SKF, which has a plant on McEver Road, manufactures the hybrid ball bearings for Tesla drivetrains in its Model S sedan.
“For SKF, we’re the largest global manufacturer of hybrid bearings, the specific bearing that goes into the Tesla car,” said business development engineer Chuck Heron. “That’s our largest hybrid production worldwide.”
The hybrid ball bearings have ceramic balls made from silicon nitride, the same material found in solar panels.
“The supply issue can be significant, because you’re competing, and there’s not an infinite supply,” Heron said.
The typical ball bearing uses steel, which is 10 times cheaper than the ceramic, said Steve Armour, director of business development.
“What industry has found, specifically with electric motors and variable-frequency-drive electric motors, is you get electrical leakage, which is a big issue,” Heron said.
The resulting leakage leads to micro pitting and cracking in the ball bearing.
“It’s a foolproof solution for this particular problem,” Heron said of the hybrid bearing and its layer of insulation.
The process begins with grinding the groove into the ball bearing. An operator constructs the ball bearing with boxes of balls at the end of the assembly line. Following a demagnetization process, the bearing is tested for vibration.
A laser etches on the part number along with a timestamp before the ball bearing is greased and covered with a seal on both sides. The bearings are then weighed to make sure there are no missing components before a final inspection by an operator.
The width tolerance in terms of precision is 15 microns, which is slightly larger than a red blood cell. As the naked eye can only perceive objects at 40 microns, precision equipment provides a reading on the factory floor.
With the struggle on the supply side for the ceramic material, manufacturing the hybrid bearings resulted in longer lead times.
“When the government first was pushing solar panels, we were getting lead times on balls anywhere between one and two years. Now, with the solar panel not being in such a demand, the lead times have gotten a lot better,” Armour said.
SKF and Tesla have worked together since Tesla’s first foray with the Roadster, collaborating on the initial design development, Heron said.
While production of the hybrid ball bearings has increased, a hurdle for electric car producers such as Tesla is the lack of dealerships. Without a dealership, Georgia and other states limit the number that can be brought into the state.
“I know that’s one of the hurdles they’re currently working on, and hopefully they’ll improve that,” Armour said.