The influence of hollow billet thickness in rotary compression

Abstract

The study presents a selection of numerical and experimental results of producing hollow stepped shafts. The first part of this study describes the advantages of using hollow parts in machine design and discusses the main fields of their applications. Next, an innovative rotary compression method for producing stepped axes and shafts is proposed. In order to estimate the technological potential of rotary compression, we performed comprehensive numerical and experimental analyses of producing hollow stepped shafts by this new technique. First, the rotary compression process for hollow parts was modeled numerically by the finite element method. The 3D modeling was made using the Simufact Forming software. The numerical results were then verified by experimental tests conducted under laboratory conditions. The experiments were performed using a machine designed by the authors of the present study. The following variables were investigated in the experiments: the effect of billet wall thickness on the process, the quality and geometry of products, and variations in loads and torques. The experimental results confirm that rotary compression can be used to produce hollow stepped shafts with a wide range of thicknesses.

A cold forging process for producing thin-walled hollow balls from tube using a plastic insert

“…In the era of energy-saving technologies, machine components characterized by low weight and high relative strength are of vital importance. This group of machine components undoubtedly includes hollow products [1][2][3] that are "empty inside" during and after the forming process. Hollow products can generally be divided into thick-and thin-walled parts [4].…”

“…A literature review shows that hollow parts having a wall thickness of at least 2 mm are an interesting group of products. Such products are usually treated as typical forgings and are usually formed from either seamless tubes or extruded solid billets, using methods in which the inner surface of the workpiece is deformed in a free-form manner (i.e., without the use of additional tools), such as compression [3,7,8], cross wedge rolling, rotary extrusion [5] and extrusion [6]. Deformation of the inner surface of the workpiece can be controlled, e.g., by using an additional rigid tool (e.g., a mandrel) in the forming process such as forging [13], orbital forging [5] and rotary compression [2].…”

“…It can be assumed that the choice of a forming technology depends on many factors, in particular the shape and dimensions of the finished part, forming conditions and the possibility of preventing standard failure modes (e.g., excessive thinning of the workpiece wall, cracks, buckling, etc.) [3,4,7,16,17,22]. If the deformation resistance of a material is relatively low, the forming process can be carried out at room temperature.…”

Theoretical and Experimental Analysis of Rotary Compression of Ball Pins Hollow Forgings

“…The research works conducted aimed mainly at determining the process parameters influence on the forming course and on the obtained forgings quality [9]. The chosen results of research concerning forming of elementary hollow shafts were presented e.g in works [10][11][12]. Moreover, the tests of hollow complex geometrically forgings (as multi-stepped shafts) by rotary compression method definitely confirmed the usefulness of the proposed technology for parts manufacturing from pipe semi-finished products.…”

Theoretical and Experimental Analysis of a New Process for Forming Flanges on Hollow Parts

“…The rollers rotate about their axis and translate in a radial direction at the same time, thus approaching the workpiece. Depending on the tool geometry, this process allows for forming stepped shafts [21][22][23][24][25], ball pins [26], and toothed shafts [27]. One of the numerous advantages of this process is the fact that the contact between the material deformed and the tools is short-lasting and variable.…”