Development of Planetary Precessional Transmission with Multicouple Gear

Particularities of Tribological Behavior of the Contact Elements of the Precessional Gear, Made of Metallic and Plastic Materials

“…3.2. POM [14] (POM plastic masspolyamide, or polyacetal-structural formula [CH2O]n: density-1.41 g/cm 3 ; melting point-175°C; breaking limit: 70-80 MPa; coefficient of friction at sliding (coupled with Steel): f=0.25-0.45; recommended operating temperature range [15,16]: dimensionally stable precision parts, small modulus toothed wheels, machine parts in permanent contact with water, rollers, cams, etc.…”

“…The transmission with precessional motion of the satellite, first proposed and patented by the first author of this paper, appeared as a result of the search for a solution to a fundamental problem such as -combining in a single mechanical transmission three performances: extended kinematic possibilities, high bearing capacity and minimal energy losses. These aspects of the problem in question dominated in all objectives throughout the research and development of precessional transmissions (PT), the answer being determined by the following very conclusive and important findings in the field of research [1][2][3][4]:  the expansion of the kinematic possibilities resides in the K-H-V and 2K-H type structures themselves, which by the range of retalled transmission ratios have no analogue among known mechanical transmissions [1];  increase in bearing capacity of the gears A B with bolts is due to the multiplicity of gearing with up to 100% pairs of teeth, simultaneously engaged, and of gears A D (with straight teeth) and A D,β (with inclined teeth)the multiple pair "convex-concave" contact geometry ot the teeth, with little difference in radii of curvature [2];  the increase in the mechanical efficiency of the TP due to the reduction of the relative sliding friction between the conjugated flanks, the improvement of the lubrication conditions by creating interdental cavities for the accumulation of lubricant, including by increasing their rolling rate due to the spherospatial motion of the satellite [3]. As mentioned in [2,5], to realize the special importance of these three performances, it is enough to perceive the dimensions of economic efficiency, obtained only from the reduction of energy losses in mechanical transmissions.…”

Modeling of Eccentric Transmission Operation in Presence of Elastic Deformations of Contacting Links

“…Researchers from the South Ural State University [5,6] and the Chisinau scientific school headed by Professor I.A. Bostan are investigating various types of the precessional transmissions [7,8].…”

Theoretical and Experimental Modelling of the Tribological Behaviour Aspects of Contact Elements in the Precessional Gearing (Pg)

“…According to previous research, it is known that unlike classical gears [1][2][3][4][5][6][7], in Precessional Transmission (PT) [8][9][10][11][12][13][14][15][16][17] the profile of the teeth of the central gear is variablea fact, which leads to the variation of the contact geometry of the teeth in the same gear, changing from one shape to another: from convex-concave -at the foot of the central gear tooth, to convex-rectilinear -towards the middle of the tooth and, convex-convex -towards the tip of the tooth.…”