The innovative design of the Schaeffler lightweight differential with the axial spline design gives significant advantages in terms of space, weight and power consumption.
Differentials of the traditional design with bevel gears require significantly more space.
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Schaeffler Group USA Inc.
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2012-01-09 | 000-003-290 DE-EN
SCHAEFFLER AG, HERZOGENAURACH/DETROIT
More compact, lighter, quieter, more efficient and with higher performance – These are the attributes of the new, innovative lightweight differential from Schaeffler’s INA brand. This is made possible by a completely new differential design.
The architecture of this space-saving component is completely different from traditional differential designs. Instead of using conventional differential pinions, the lightweight differential has spur gears arranged as a planetary gear set in one plane, as used in automatic transmissions.
This means that the required space and weight are significantly reduced and the potential torque capacity is noticeably increased. “The lightweight or spur gear differential has enormous advantages”, explains Dr. Tomas Smetana, Head of Advance Development at the Transmission Business Unit, Schaeffler Automotive. “We save up to 30 percent weight compared with a classic bevel gear differential while creating up to 70 percent more axial space due to the streamlined design. In specific terms, this means a reduction in mass of up to three kilograms per differential and 90 millimeters of additional space in the transmission!” The lightweight differential is thus an appropriate response to the challenge of increasing engine torques and the space gained in the transmission creates more room for larger double clutches or transfer boxes, as well as electronic components for modern hybrid solutions.
“The narrow lightweight differential design also allows the use of new bearing concepts with optimized friction and makes a measurable contribution to reducing fuel consumption and CO2 emissions”, says Norbert Indlekofer, member of the Executive Board and responsible for transmission systems at Schaeffler.
In addition, the lightweight differential – beyond creating space for hybrid modules – is also a key element for the innovative eDifferential from Schaeffler. This component combines an electric drive with the option of controlling the drive power in each wheel individually. The active electric differential gives a significant improvement in load transmission when travelling on surfaces with varying friction values. It also supports the steering function. This facilitates torque vectoring (distribution of torque between the left and right wheel), which is beneficial for driving dynamics, safety and comfort. If eDifferentials are used on both axles, this also enables the longitudinal distribution of drive torques. It is also possible to intervene in driving dynamics through selective power supply instead of through braking intervention and thus power reduction as is the case with ESP. With the solution presented in the Schaeffler concept vehicle ACTIVeDRIVE, the mobility supplier is showing the way ahead for such an electric concept in a vehicle drive system.