DETROIT – Sweden-based supplier SKF will integrate a sealing-and-sensor subassembly into an existing engine in 2006 that will save critical underhood space, the company announces here at the Convergence International Congress on Transportation Electronics.
Sensors that accurately monitor crankshaft position and axle rotation are elements of advanced controls systems that can improve fuel mileage and help prevent vehicle rollovers. But integrating the sensors into existing vehicle designs and manufacturing processes has been problematic.
SKF’s system combines a rear crankshaft seal and retainer with a crankshaft position sensor.
By locating the sensor at the rear of the engine, where there were no dimensional constraints, the auto maker saved considerable underhood space at the front of the engine where the previous sensor assembly was mounted, SKF says.
“We are constantly analyzing ways of ‘sensorizing’ our seals, like developing ferro-magnetic rubber compounds for exciter rings, because of the potential advantages to enhance the driving experience,” says Scott Fournier, director-original equipment sales for SKF’s automotive business unit.
“Because seals are often the most outboard component on a rotating shaft, they’re ideally located for mounting sensors and making the required electrical connections.”
SKF’s sensor is affixed to the retainer. During engine operation, it generates a signal used by the onboard computer to determine crankshaft position, as well as spark plug firing order and timing. The signal is generated by the sensor’s interaction with a rotating timing wheel that is mounted to the crankshaft.
“SKF is maximizing the powerful features of electronic sensors by integrating them into seal assemblies, or by creating completely new types of sensor components,” Fournier says.
SKF also helped an undisclosed North American auto maker add a safety-enhancing sensor system to the manufacturer’s existing drivetrain. The system is comprised of a powdered-metal tone ring, a sensor and a specialized rubber compound that improves mounting capability.
The molded rubber expands in the application to accurately locate the tone ring on the axle.
The sensor is placed above the tone ring assembly and sends information to an electronic control unit that manages vehicle braking and stability control. The data is used to detect speed differentials and oversteer that can lead to rollover accidents.
When a potential rollover situation is detected, the stability-control system automatically makes braking adjustments to stabilize the vehicle’s position.
SKF has 38,000 workers worldwide, including more than 9,000 employees in its automotive division.