Horn-Muller-von der Wense Gearbox: A Novel Approach to Uninterrupted Torque Transmission During Gear Changes (HMW-Gear)

The Horn-Muller-von der Wense Gear (HMW-Gear) is a newly developed transmission system that is capable of transmitting uninterrupted torque during the switching process and was developed and manufactured over a three-year period. The project began with a purely mathematical approach, wherein various functions were analyzed to address the question of how to change gears without interrupting torque. Significant efforts were made to develop special cogwheels based on this approach. An additional test bench was constructed. In addition to a fun-damental explanation of the invention and detailed information on its implementation, initial validation measurement results are presented in this publication. The HMW -Gear switching principle is protected under the European Patent Law [4].

I. Introduction

Gear transmissions are well-known components of vehicles, machine tools, and other devices. Gear transmissions allow for shifting by altering the gear translation ratios, resulting in changes to both speed and torque. In typical configurations, a drive shaft and a driven shaft are arranged in parallel to each other. However, existing approaches do not adequately explain how uninterrupted torque transmission during gear shifting can be achieved. Although modern automatic gearboxes often do achieve uninterrupted torque transmission, they do so with relatively complex setups. The Horn-Muller-von der Wense Gear (HMW-Gear) represents an improved gear transmission unit that achieves uninterrupted torque transmission during shifting while maintaining load coupling at the driven ar-rangement throughout the shifting process. The HMW-Gear's design consists of a drive shaft and a drive gear, which are coupled together. The driven arrangement comprises a driven gear connected to a driven shaft. The driven gear incorporates two stages, which is unique compared to other approaches in literature. The gear-shift is actuated by a hydraulic cylinder and moves the drive-gear along a certain three dimensional trajectory to ensure continuous cogwheel engagement at all times. However, due to the loss of one tooth at a minimum throughout the cogwheels surface, one area of discontinuity results. This area does not comply with the basic rules of teeth engagement. Hence, this area must be prevented to be part of the switching process. Fig. 1:

CAD model of the HMW-Gear