Spherical contact mechanical analysis of roller cone drill bits journal bearing

Resharpening of the twist drill bits

To get a good performance from a drill bit the sharpening must be done correctly, this means that all the angles and the lengths of the edges must be exactly as established and will not occur during the grinding edge of the material structural modifications. To execute the correct sharpening are therefore required special equipment and dedicated grinding machines. The geometric elements to cons...

Bearing designs - Tapered roller bearing units

Numerical Analysis of Grease Film Characteristics in Tapered Roller Bearing Subject to Shaft Deflection

The shaft deflection is one of critical factors that deteriorate the grease lubrication state inside the tapered roller bearings (TRBs). So, in this paper, on the premise of the TRB subjected to the combined loads and the shaft is deflected, the grease lubrication model at the TRB contacts was constructed, in which the interaction loads, linear and angular displacements of the bearing parts wer...

Multi-crack analysis of hydraulically pumped cone fracture in brittle solids under cyclic spherical contact

The evolution of surface damage in bilayers due to cyclic spherical indentation in the presence of incompressible lubricant is studied using an all-transparent glass/polycarbonate system as amodel formore practical applications such as dental crowns and rolling contact fatigue. In situ observations and post-mortem material sectioning reveal that inner cone cracks evolve sequentially from the co...

Regional Stability Analysis of Rotor-Ball Bearing and Rotor- Roller Bearing Systems Considering Switching Phenomena

Abstract—In this study the regional stability of a rotor system which is supported on rolling bearings with radial clearance is studied. The rotor is assumed to be rigid. Due to radial clearance of bearings and dynamic configuration of system, each rolling elements of bearings has the possibility to be in contact with both of the races (under compression) or lose its contact. As a result, this ...