This study proposes a self-pumping gear unit for decreasing pressure in a gear box in order to reduce windage loss. This method was found having heat generation with temperature rise over 100°C which cause thermal expansion in the test rig and bring mechanical contact of gears and shrouding parts. Considering this due to adiabatic compression of air during messing process, relief pocket which may bypass air which is trapped between meshing teeth was examined. This paper evaluates effectiveness of the pocket geometry to reduce heat generation, and discovers its mechanism in detail. As a result, although the pockets is effective in making temperature rise less, this cannot be enough to resolve the issue. Furthermore, a mechanism of this heat generation is discussed in terms of heat cycle. It consists of typical changes such as isovolumetric, isobaric, and adiabatic changes. By calculating the required kinematic work of this cycle, it is discovered that the heat generation relates to a power loss which is done by the work due to gears rotating against the pressure difference between high pressure and low pressure region.
各種検索
サポート
ヘルプ