Rethink delivers a new generation of split bearings

Wyko subsidiary Revolvo has developed a new generation of split roller bearings (shown below) which, it claims, offer improved performance and simplified inspection and maintenance.

SRBs are up to 80% faster to fit and remove from shafts than solid bearings, but they have traditionally been hampered by the need for regular inspections which can result in the cage clips falling out.

Revolvo started the new design from scratch and came up with several innovations including:

• designing a new cage clip which is kept in place by spiral pins during assembly and disassembly, avoiding the problem of lost clips, and giving maintenance engineers a free hand;

• providing "pry" slots, making it easier to disassemble the cartridge and pedestal without breaking parts;

• using profiled rolling elements to minimise potentially damaging edge stresses that can occur during dynamic misalignments;

• including CNC-bored pockets for the rollers in the machined brass cage, to prevent skewing which can cause edge loading and can shorten bearing lives;

• choosing an easy-to-machine grey case iron for the bearing housing; and

• incorporating ribs in the pedestal housing to make it more rigid.

The SRBs are statically self-aligning, avoiding the need to realign the bearing housing to the shaft or other in-line equipment. They are designed to accept three degrees of shaft misalignment.

The brass cage allows the SRBs to be operate at temperatures up to 140°C and at speeds 25% faster then normal, as long as the thrust loads stay within design limits.

Revolvo claims that the new SRBs perform well in harsh operating conditions, even with misaligned shafts, unlike solid mounted roller bearings which can suffer from non-centric seals, leading to bearing failure. The SRBs offer a choice of eight different sealing systems.

Revolvo has recently invested £1.5m in new machinery for its Dudley plant where the new SRBs are being produced in light, medium and heavy versions, in diameters from 35-600m. There are also non-catalogue versions up to 1.4m outer diameter.