Experimental studies on spiral groove thrust bearings

This article discusses about the role of bearing parameters including those of the grooves on the stiffness and load capacity of Spiral Groove Thrust Bearings (SGTB) at high rotational speeds. A tandem arrangement of Aerostatic Thrust Bearing (ASB) with an SGTB assembly is investigated. Studies revealed that optimization of groove depth and land area of SGTB play a key role in its load carrying capacity. The optimum inner land radius of SGTB developed by BARC for its cryogenic turboexpanders is found to be 17–19 mm, any variation on either side leading to a reduction in bearing stiffness. After development of the set-up with the mentioned tandem bearing arrangement, a preliminary experiment was conducted with the rotor running up to 3000 Hz.