Bearings – devices which allow two surfaces to pass over each other with minimum friction – are one of the commonest mechanical components. In an agricultural setting, bearings can be found in all kinds of vehicles, and also in the wide variety of task specific machinery found on a typical farm.
One invention which is often found in an agricultural context, which would not be possible without bearings, is the power take off (PTO) drive. This is found on most tractors, some other agricultural vehicles, and occasionally on road vehicles designed for industrial use, such as Land Rovers and Mercedes Unimogs. A power take off drive is a shaft separated from the engine of the vehicle by a clutch. When the clutch is engaged, the shaft spins at a speed governed by the speed of the engine. This shaft can then be used to drive a variety of agricultural or non agricultural machinery, such as generators, chippers, table saws, bailers, water pumps, and hydraulic systems. Obviously, the bearings in such a system have to be up to the job, as some of these applications will place a high load on the components.
There are no particular types of bearings associated uniquely with the agricultural world, however any kind of heavy duty bearing will likely be used for obvious reasons. Tapered roller bearings were first invented for agricultural applications, and have since migrated to industrial and plant vehicles. These cone shaped bearings are used on the axles of many heavy goods vehicles, including agricultural vehicles. They are designed to bear not only the lateral but also the axial forces associated with the drive axles of heavily loaded vehicles, and when fitted in pairs they effectively form a frame inside which the axle sits. These bearings have greatly reduced wear and tear on many components of modern agricultural vehicles.
Agricultural bearings are expected to perform in very demanding environments. Modern farming is heavily reliant on a vast range of machinery, without which everything would grind to a halt. Think of all the times you’ve seen a tractor out in the pouring rain or driving snow, ploughing a muddy field. Agricultural bearings have to work in all weathers, on all terrains. And possibly more than in any other industry, they may at any time be expected to out perform their specification. Think about it: a farm hand is far from home, the light is fading, and he or she needs to get a heavily laden trailer back to the farm with their tractor. Are they really going to stop to consider if the load might be overweight? The demands of the agricultural industry are immense, but modern bearings are up to the challenge.
And when agricultural bearings do require repair, sometimes the affected machinery is in a distant location, across muddy fields, up steep slopes or through thick trees. Agricultural engineers have to be tough and resourceful, and extra thorough when it comes to looking after bearings.