Schaeffler develops seamless stop-start system for automatic transmissions

German-based Schaeffler Group, a leading supplier of torque converters, says that it has developed an easily integrated stop-start system for vehicles equipped with automatic transmissions. According to Schaeffler, fitting a slushbox with stop-start tech is difficult because the torque converter between the engine and trans is always engaged. However, Schaeffler claims it has designed a permanently engaged starter that transforms the torque converter into, as Ward’s Auto says, “a useful weapon in reducing fuel consumption.”

Schaeffler says the stop-start system utilizes a one-way clutch between the crankshaft and the torque converter’s starter ring gear, allowing the ring gear and the starter motor pinion to remain in contact.

Jeff Hemphill, Schaeffler Group’s U.S. region director of technical product development, told Ward’s Auto about the benefits of the firm’s seamless stop-start system:

If you have just a normal starter, you would have to wait until you get to zero, and then you’d get a few bumps. At zero, the engine can start cranking again. Can you imagine if you’re a driver at a green traffic light with your foot on the gas waiting for a count of three before something happens? That’s not a very acceptable condition.

According to Hemphill, Schaeffler’s permanently engaged starter makes for a restart that:

Happens silently because it’s a friction connection, not a gear-tooth trying to engage. It can quickly re-engage and restart and recrank the engine silently.

Hemphill declined to discuss pricing of Schaeffler’s seamless stop-start unit. However, he did reveal that such a system needs to cost around $100 per vehicle. How close is Schaeffler’s system to that price? Well, as Hemphill told Ward’s Auto, “We can’t guarantee that we’re going to meet that target, but we think we’re on the right road.”

[Source: Ward’s Auto]