Effects of herringbone groove patterns on performance of vertical hydrodynamic journal bearings

Abstract

An experiment to investigate the performance of vertical herringbone grooved hydrodynamic journal bearings was conducted to study the effects of groove patterns on the pumping sealing and stiffness of the bearings. A test rig was designed and constructed for this purpose, and various herringbone groove patterns on the shafts were tested at rotational speeds ranging from about 200 to 2100 rpm. The shafts were made of aluminium with diameters of 46.2 mm, while the sleeve was made of a transparent perspex pipe of 120 mm length. Pressure taps were made on the sleeve to observe the pressure profiles generated along the sleeve. Among the herringbone groove patterns tested, the S:L-S:L (Short:Long-Short:Long) pattern with a groove length ratio of 4.5:5.5 - 4.5:5.5 and the L:S-S:L (Long:Short-Short:Long) pattern with a groove length ratio of 7:3 - 3:7 show the most promising performance in terms of pumping sealing and stiffness (as revealed from their pressure profiles).