Study of the performance of a worm gearing transmission enhanced by hydrostatic lubrication

摘要

According to the work plan, the first year is to be devoted to the analyses of the geometrical and kinematic properties of meshing and the load sharing of the contacting teeth, then the second year is to be devoted to the selection of a hydrostatic lubrication configuration on the gear surface and the analysis of the hybrid (hydrostatic and hydrodynamic) lubrication at the contact. The work in the first year, 1 Jan. to 31 Dec. 1992, was summarized in an extensive status report in which the methodology of generating wormgear surfaces was developed and a double-enveloping wormgear type was selected and analyzed, whose geometrical parameters and dimensions were chosen basically in accordance with the AGMA gear standards. In January 1993 an oral presentation of the first year's work was made at the Army VPD. Several questions were raised after the presentation. Among them one concerned the necessity of following the AGMA standards in adopting the 20 deg normal pressure angle. It was felt that making the pressure angle on the loaded side of the tooth close to 0 deg would be more effective in producing the needed torque. In addition it was suggested to explore the possibility of increasing the tooth depth. A larger tooth depth would provide a larger bearing area, hence a smaller unit load. To respond to these suggestions, the original work plan was modified and our effort was directed to the search of promising asymmetric tooth profiles. The status report describes the findings from this effort.