Visual assessment of dynamic processes in the hinges of universal spindle heads

Abstract

In modern rolling mills, electrical energy is converted to mechanical energy, which is transferred to the working rollers and finally converted to useful work in the deformation zone. Energy transfer and interaction of the drive components may be represented in the form of three successive stages of different physical types [1]. This sequence, consisting of stages of spontaneous motion C i , action, D i , and reaction O i , may be represented by modules with subscripts i = 1‐3. Accordingly, drive components of different scale interact with one another. Motion is continuously converted from one type to another, within a sequence that branches in several directions. In that case, the motion may be represented as a branched chain that has a particular orientation in space and unfolds over time. At the equipment level, the structure of the motion is shown in Fig. 1. The electric current (motion) acts through its electromagnetic field on the rotor of the electric motor. This action is converted (as a reaction) to spontaneous motion of the electric motor, which is then transferred by the action of the transmission of the system. The reaction in the system components leads to motion, and the transmission acts on the executive organ. Passing through all three stages ( O C D ), the executive organ performs a technological action; for example, in a rolling mill, it acts on the metal. In reaction to the action of the tool, the metal moves to take on the required form. When motion is transferred to the junctions of the mechanical components, with change in mechanical energy density, intense dynamic processes occur, affecting the performance of the whole rolling-cell drive. In particular, in the blade‐bearing contact of a universal spindle head, powerful local dynamic phenomena arise, as shown by industrial experiments in [2]. The dynamic load is an order of magnitude greater than the static load, and hence intense wear of the components may be expected. Visualization is the most informative and reliable means of studying these processes. One method of visualizing the dynamic loading of machine components over time is the polarization‐ optical approach (dynamic photoelastic method) [3]. In the present work, this method is used to study wave processes in the contact zones of the components of a universal rolling-mill spindle. In the present work, the energy transfer in the contact zones of the spindle hinge—yoke‐bearing, bearing‐blade, etc.—are studied within a plane cross section passing through the axes of the contacting components (Fig. 2). The direction of energy transmission is taken into account here. The spindle consists of two heads, one on each side. Energy transmission through the spindle is associated with different loading of the components in the head hinges. In one head, the torsional force is transmitted from the blade to the bearing and then to the yoke. In the other head, the yoke acts on the bearing and then on the hinge blade. In the present work, we consider three possible contact zones of the spindle components. The first model (Fig. 2a) permits the simulation of wave processes in plane A between spindle blade 1 , bearing 2 , and yoke 3 . We assume that the energy is transmitted from the spindle blade to the yoke. The model in Fig. 2b corresponds to wave processes in plane B , perpendicular to plane A . Using this model, we assess the dynamic processes in the contact zone of the cylindrical section of bearing 2 with yoke 3 . The forces in the cross section of the contact zone