Use of thrust cone bearings to increase efficiency of helical gears

• Applicant: Professor Dr.-Ing. Armin Lohrengel
• Subject Area: Engineering Design, Machine Elements, Product Development
• Term: from 2011 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 200476772

Thrust cones offer an excellent opportunity to raise the efficiency of helical gears. As a hydrodynamic axial sliding bearing they compensate axial forces generated by the helical gears close to their point of origin. Due to the small distance between thrust cone and pitch circle the differential velocity during operation is lower in the thrust cone bearing than in conventionally axial bearings, which leads to a significant reduction of friction losses. Aim of the proposed project is to gain better understanding about the overall system thrust cone bearing to develop application specific design guidelines and expand the limits of application for this technology. In addition to the work of the first project period, in which especially the transition behavior from mixed friction area to hydrodynamic lubrication region was investigated, boundaries for thrust cones operating in mixed lubrication regime shall be determined in the second period. Even so the usual point of operation for thrust cone bearings is clearly in the field of hydrodynamic lubrication, in practice damages mainly occur during start-up and braking situations when the mixed friction region needs to be traversed. The determination of design characteristics by extensive experimental studies on the twin-disc test rig at the IMW are intended to allow resource-efficient design of thrust cone bearings with a reliable fatigue life prediction. A further aspect of the second period is the machine dynamic view on the system behavior of thrust cone transmissions compared to gears with conventional bearings. For this purpose the effects of the thrust cone bearing on the vibration and damping behavior and the efficiency of the transmission system shall be detected, on the one hand simulative by using multi-body-simulations, on the other hand experimentally by building a comparing gear set. Through the project the performance of the thrust cone technique shall be further increased to contribute to more energy efficient transmissions.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1551: Resource Efficient Constructional Elements