Rookie Formula SAE Michigan participant Matt Kramer designed a mechanically automated clutch that won Altair Engineering’s first place award for most innovative design at the 2014 competition.
Kramer’s clutch design for Lafayette College’s Formula SAE 2014 racecar was a solution to a perplexing problem.
“The 2013 racecar had paddle shifters on the steering wheel to send an electrical signal to the engine for a transmission shift. But that type of a design doesn’t provide the bio-feedback that you need. When it’s all mayhem on the track and everything is loud and you’re bouncing around, it’s difficult to know if you’ve successfully shifted,” the May 2014 mechanical engineering graduate of Lafayette College in Easton, PA, said in an interview with SAE Magazines.
At the start of his senior year, Kramer talked with the school’s Formula SAE advisor, professor Scott Hummel, about developing an entirely new clutch system. “We started the process by doing hand sketches and hand calculations on a white board in a classroom setting,” Kramer said. Next came 3-D CAD drawings in Autodesk Inventor. It was six design iterations later before any parts were manufactured.
“From the first to the final iteration, the biggest challenge with the design was timing the clutch and shift sequences. When you go to downshift, we wanted the clutch to disengage first, then the shift to happen, then the clutch to re-engage,” said Kramer, adding, “Through team discussion and the support of our professor, we were able to accomplish this.”
The Lafayette car’s mechanically automated clutch netted the team $1000 by winning the Altair Engineering William R. Adam Engineering Excellence for best innovative design during the May Formula SAE competition at the Michigan International Speedway in Brooklyn, MI.
Chayan Basak, Senior Manager of Technical Field Operations for Altair Engineering in Troy, MI, said the Lafayette car’s clutch design is not the norm at Formula SAE competition.
“Most teams have separate shift and clutch actuators. Shifters are typically done with a pneumatic actuator, mechanical cable, or solid linkage with an additional lever that solely operates the clutch, either by cable or hydraulic fluid. Lafayette’s innovation is combining two tasks into one mechanism,” Basak explained to SAE Magazines.
The mechanically automated clutch uses two cables, one for shifting and another for clutching. “But they are connected to a mechanism that pushes/pulls each of the cables in the correct order/timing using only one lever. Because the timing of the clutch is ‘baked’ into the mechanical design of the shifter, the driver has one less thing to worry about while on the track,” Basak said.
Lafayette’s 16-member, all-rookie Formula SAE team redesigned nearly every system from the school’s 2013 racecar.
Said Kramer: “Our team captains, Matt Tindall and Matt Cassera, attended Formula SAE Lincoln in the summer of 2013 to look at what all the teams were doing. They were on a scouting mission. They were observing. It was essential.”
Major renovations to the 2014 car included a switch to a drop-chassis (versus the prior flat-bottom chassis), an adjustable differential housing (replacing a static differential housing), and a Suzuki LTR 450-cc engine (replacing a Yamaha R6 600-cc engine).
Lafayette’s 2014 racecar scored first in fuel efficiency, completing 20 laps with an average adjusted lap time of 86.296 s. Total fuel consumed was 1.984 L (0.524 gal).
Said professor Hummel: “The semi-automatic transmission, no clutch pedal or separate lever, allowed our drivers to easily change gears. This helped them to keep the engine running at a low rpm, leading to better fuel economy.”
Hummel, who serves as the William A. Jeffers Director of the Engineering Division at Lafayette College, noted that “our team took nearly one-third of the weight out of the car. A team of rookies did that and won the fuel efficiency event. That’s impressive.”
Lafayette’s team also was recognized as the first place winner of the 2014 FEV Powertrain Development Award. The award is based on various powertain-relevant aspects, including fuel economy, performance, durability, and cost.
The team placed 48th overall at FSAE 2014.
For more coverage of FSAE 2014 by SAE Magazines, go to http://articles.sae.org/13248 and http://articles.sae.org/13251.Continue reading »