Uses Of Combined Roller Bearings

Combined roller bearings and mating steel profiles are used in a variety of different applications ranging from oil drilling and exploration equipment to fork-truck attachments, and are capable of dealing with loads from tens of kilos to up to hundreds of tonnes.

Because of their desirable ability to operate with precision, they are also commonly used in pieces of medical equipment. Their reliability in demanding environments, makes them the ideal choice for furnace chargers and dischargers, and brick making.

They are comprised of a 'maximum-capacity' cylindrical roller bearing, which in turn is filled with steel rollers, without a cage to separate them.

It works by rotating on a weldable steel hub, known as a radial roller. Inside this hub there is another bearing, a needle roller, set at 90 degree angle to the radial roller. This is known as an axial roller.

Both bearings are sealed with a hybrid of rubber and metal seals.

There are a number of performance advantages with these systems. For instance they can be used both vertically and horizontally, accepting cantilevered loads and telescopes. The design means that they are also capable of operating in even the harshest of environments. Crucially, when designing a heavy duty system it is highly unlikely that the radial bearing will crab or lock its steel section, as any twisting action is immediately counteracted by the axial bearing running into and along the web.

The issue of crabbing is one that engineers have struggled to overcome for a number of years. For example, manufacturers in the trucking industry have long been aware that there was a tendency within the mast for the bearings they were using to crab. The mast would be susceptible to skid, crab, or in some cases even lock in the mast channel.

To combat this, a second side load roller bearing was used. This combined roller bearing therefore combined the main load carrier, with the anti-twist bearing.

Truck manufacturing has all but died out within the UK, but the same technology is used in other parts of British industry such as the machine used to lift the 50 tonne wing of the A380 aeroplane. Enormous bearings and special welded profiled rails were required. In contrast, a production engineer can use four small combined bearings and two small steel profiles to create a cost-effective slide, moving a work piece from one machine to another.

This technology has also solved engineering problems in industries such as oil drilling, exploration equipment, as well as machines used to lay down pipes and cables on the seabed.