THE SPHERICAL ROLLER BEARING MILL A QUARTER OF A CENTURY ON

In the early 1970s, quotations were received for a new 2133 mm pressure fed mill. Among the quotations was a new concept for the Australian sugar industry with inverted ‘V’ side frames held in place by four pins. It was fitted with spherical roller bearings. There was little difference in cost compared with a conventional brass bearing mill. It appeared to offer several advantages: • Ease and speed of dismantling and assembly of the whole of the mill for maintenance. • The free movement of hydraulics and ease of mill settings. • No bituminous grease around the mill cheeks and no cooling water. • No wear on roller shafts. • Ease of mounting and demounting of bearings on the shaft by oil injection. • The use of roller bearings on the actual mill completed their use throughout the mill drive and mill and made for a very low energy unit. • Saving in lubrication costs. The first mill was installed at Pleystowe in 1974 and following its performance the order for two more complete units and a similar type pressure feeder for attachment to a conventional mill was proceeded with and installed in 1976. All of these apparent advantages have been realised and the units have proved to be some 15% cheaper to maintain than their conventional brass bearing counterpart. The savings are due mainly to the convenience of maintenance because of the design and also the elimination of any repairs to the roller shaft because of wear and stress caused cracking. These mills use less grease during service. However, the grease quantity needed to regrease the bearing after a complete clean and examination every three to five years tends to offset that advantage. This paper aims to illustrate problems that have been met and the means adopted to overcome them. It also aims to show the advantages of these mills and their spherical roller bearings