An Improved Algorithm for Calculating Friction Force and Torque in Involute Helical Gears

Time varying frictional force and torque are one of the main exciting sources of vibration in helical gears. This paper presents an approach to determine the friction force and torque in involute helical gears considering nonuniform load distribution along contact lines. An analytical load distribution model is employed and extended to obtain the load per unit of length along contact lines. Friction force and torque models under nonuniform assumption are derived. Comparisons of the determined friction force and torque with the results from uniform assumption are made. In addition, the differences between constant friction coefficient and varying coefficient are revealed. Moreover, two typical design cases of helical gears are studied. Results show that the fluctuations of friction force and torque under uniform assumption are more significant than those under nonuniform assumption in sample I for a single tooth, but less significant for the sum of those of the three teeth, while in sample II, the fluctuations under uniform assumption are less significant than those under nonuniform assumption. The friction coefficient induced difference is negligible compared with the difference induced by load distribution assumptions.

[1]  B. W. Kelley,et al.  Instantaneous Coefficients of Gear Tooth Friction , 1961 .

[2]  P. Velex,et al.  An Analytical Expression for the Time-Varying Contact Length in Perfect Cylindrical Gears: Some Possible Applications in Gear Dynamics , 1996 .

[3]  P. Velex,et al.  Experimental and Numerical Investigations on the Influence of Tooth Friction in Spur and Helical Gear Dynamics , 2000 .

[4]  Rajendra Singh,et al.  Sliding Friction-Induced Non-Linearity and Parametric Effects in Gear Dynamics , 2001 .

[5]  Ian Howard,et al.  THE DYNAMIC MODELLING OF A SPUR GEAR IN MESH INCLUDING FRICTION AND A CRACK , 2001 .

[6]  P. Velex,et al.  An analytical study of tooth friction excitations in errorless spur and helical gears , 2002 .

[7]  Rajendra Singh,et al.  Strategies for Modeling Friction in Gear Dynamics , 2003 .

[8]  Anders Klarbring,et al.  A flexible multi-body approach for frictional contact in spur gears , 2004 .

[9]  Amiya R Mohanty,et al.  An algorithm for determination of time-varying frictional force and torque in a helical gear system , 2007 .

[10]  Rajendra Singh,et al.  Effect of sliding friction on the dynamics of spur gear pair with realistic time-varying stiffness , 2007 .

[11]  Rajendra Singh,et al.  Inclusion of sliding friction in contact dynamics model for helical gears , 2007 .

[12]  Amiya R Mohanty,et al.  Determination of time-varying contact length, friction force, torque and forces at the bearings in a helical gear system , 2008 .

[13]  Rajendra Singh,et al.  Prediction of dynamic friction forces in spur gears using alternate sliding friction formulations , 2008 .

[14]  José I. Pedrero,et al.  Load distribution model along the line of contact for involute external gears , 2010 .