Energy optimized oil filtration for automatic transmissions

L. Petersen*, H. Brengelmann, G. Mathy, A. Heinen, Hengst SE, Germany

Worldwide almost every second new car is equipped with an automatic transmission. The market share of automatic transmissions is expected to increase within the next years.

Most of all automatic transmissions have an oil circuit actively driven by an oil pump. The oil fulfills several functions: cooling of the transmission, lubrication of gears and bearings as well as transferring force in order to operate hydraulic actuators. The purity of the oil is important for the life span of the components. Thus, usually one or several filters are integrated within the system. Nonwovens as well as metal meshes are used as filter media depending on the specific requirements.

Impurities can be generated during production and during operation of the transmission. The impurities of the transmission oil can be mineral particles, metal wear and oil degradation products. At least a fraction of the substances is metallic, so besides filtration magnetic separation is used to remove those particles. However, there is a variety of different automatic transmission concepts such as torque converter, dual-clutch or continuously variable transmissions. Different concepts and the specific realization by the manufacturer require different levels of oil purity.

Worldwide the CO2 limits for vehicles get stricter. Thus, transmissions need to get more efficient as well. The oil supply accounts for about one third of all energy losses within modern automatic transmissions. Optimization here is a strong leverage to increase the overall efficiency of a transmission. Thus, for a filter manufacturer it is a reasonable development goal to minimize the differential pressure of the filtration system under the constraints of the required oil purity, package and costs. The filtration system also needs to be functional under harsh conditions such as typical cold start requirements with (oil) temperatures down to -40°C.

Development objectives at Hengst are intelligent integration of magnetic separation, balancing different filtration stages and flow optimization within the filtration housing.

In the talk energy optimized oil filtration solutions for specific requirements will be presented...

Session: L9 - Depth Filtration and Adsorption - Applications
Day: 14 March 2018
Time: 13:00 - 14:15 h

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