Superelement-Based Modeling of Load Distribution in Large-Size Slewing Bearings

Abstract

The supporting structures in large-size slewing bearings are highly flexible. In order to choose the proper bearing and shape the load-carrying structure one must estimate the distribution of forces among the individual rolling elements. Advanced numerical models are needed for this. An original method of modeling the rolling element-track system is presented and its usefulness for modeling large-size bearings is demonstrated. The results of an exemplary analysis are presented in the form of graphs and figures. The superelement-based discrete bearing models are so far most comprehensive and take into account all the phenomena involved in the bearing-supporting structures system. The application of the finite-element method and the models based on the track-rolling element-track superelement made it possible to determine the effect of the deformability of the supporting structures and the nonuniformity of their flexibility on the loading of the rolling elements in the two-row bearing. The use of formulas which do not take into account the flexibility of the supporting structures to determine the distribution of the load among the rolling elements is unacceptable.

Optimization of the support structure of large axial-radial bearing of overhead type manipulator

“…But in the investigated case, these deformations were not critical; therefore it was reasonable to increase these deformations, while decreasing the reaction forces. Moreover, the final support construction is less stiff than the initial, which is not in agreement with suggestions of stiff roller-bearing support [1,[4][5][6][7][8]. But in the investigated case only such solution enabled more uniform reaction force distribution, while simultaneusly satisfying criterion of allowable stress.…”

“…However, in the investigated case these deformations were still below the allowable deformations. The proposed solution is an example of a more favourable flexible bearing support in contrast to the general stiff bearing support recommendations [1,[4][5][6][7][8].…”

“…Many researchers have found stiffness of the supporting structure as a crucial constructional problem of large slewing mechanisms [1,[4][5][6][7][8]. They concluded that the supporting structure needs to assure stiff and uniform support around the bearing circumference to avoid stress peaks and large deformations of the bearing.…”

A catalogue capacity of slewing bearings

“…To avoid unwanted increase in the size of the numerical model, the rolling elements in the bearing are substituted by so-called superelements introduced in works [10, 16,17]. Linear element with the non-linear characteristics, which is determined on the basis of equivalent characteristics of contact zone [17], is the main fragment of the superelement.…”

Modeling of carrot root radial press process for different shapes of loading elements using the finite element method

“…The problem issue of contact pressures, which have not included the friction between the contact elements, was solved by the use of special instrument called GAP [49] . As a result, a three-layer discrete model was built, which included: 576 PLANE 2D elements of core layer, 72 PLANE 2D elements of cambium layer, 1098 TRIANG elements of the core layer, 1456 nodes and elements having 2912 degrees of freedom.…”