Effect Of Radial Force Research Articles

Investigation on mechanical behavior of planetary roller screw mechanism with the effects of external loads and machining errors

The effects of radial force and machining accuracy were ignored in previous studies, which considerably affected load distribution and fatigue life for planetary roller screw mechanism (PRSM). This study establishes mechanical models that incorporate radial load and machining error. These models consist in using equivalent contact load and deformation to estimate axial loads, and applying Hertz contact theory and thread cumulative deformation to calculate contact loads of all threads. The results show that the contact forces over threads periodically change considering radial loads. Moreover, the load distribution and fatigue life dramatically change with the variation of machining errors. Based on load coefficient, the roller threads are modified so that the fatigue life and load distribution uniformity can be improved.

Effects of radial force and log position on the stem on ring-debarker efficiency in frozen black spruce logs

ABSTRACT The effect of the radial force applied by a ring debarker tip to frozen black spruce logs, obtained at three positions on the stem, was studied. A one-arm ring-debarker prototype was developed, which controlled the radial force, rake angle, and cutting and feed speeds. The experiment consisted of debarking logs using three different levels of radial force. The rake angle (80°), tip overlap (20%), and cutting and feed speeds were kept constant. Debarking quality was evaluated by two criteria: the proportion of bark remaining on log surfaces and the amount of wood in bark residues. Log characteristics (dimensions, eccentricity, and knot features), bark/wood shear strength, and basic densities of sapwood and bark were also measured. Experiments revealed that log position on the stem did not affect debarking quality. The results also showed a significant effect of the radial force: the amount of bark remaining on log surfaces increased and the proportion of wood in bark residues decreased as radial force decreased. The effects of log eccentricity, bark/wood shear strength, and the proportion of knot surface on the debarking quality were examined. These results give useful information to improve debarking quality within the studied range of radial force, log diameter, and debarking parameters.

The Effect of Radial Force on Pull-in Instability and Frequency of Rigid Core Circular and Annular Plates Subjected to Electrostatic Field

In this work static pull-in instability and frequency analysis of circular and annular plates in electrical field was studied. The plate is modeled based on classical plate theory with nonlinear Von Karman strain-displacement field. The governing equation of motion and boundary conditions were obtained using Hamilton principle. For this purpose potential and kinetic energies and the work done by radial and electrostatic force are obtained. Governing partial differential equations were reduced to ordinary differential equations by Galerkin's method. Then, static pull-in instabilities of clamped circular plate and annular plate with clamped-clamped and clamped-simply boundary conditions were analyzed by arc-length continuation method. The effect of rigid core, radial load, geometric nonlinearity, inner radius and boundary conditions on pull-in instability and frequency of the plate has been studied.

Radial forces and vibration analysis in an external‐rotor switched reluctance machine

In external-rotor electric machine configurations, the rotor can be the major source of noise. This study analyses the distribution and the effects of radial forces and vibration in a 6/10 external-rotor switched reluctance motor designed for an E-bike application. The distribution of the electromagnetic force vector depends on the switching sequence, the geometry of the motor and the direction of rotation. Therefore, the effect of the switching strategy on the rotor radial force waveform has been analysed. It is shown that adjusting the turn-on angle can reduce the high rate of change of radial force waveform at the pole corners. The effect of switching angles on the reduction of rotor vibration has also been examined.

XLI. On the precise effect of radial forces in opposing the distortion of an elastic sphere

XLI. On the precise effect of radial forces in opposing the distortion of an elastic sphere