An agricultural machine is a high-efficiency operating machine under all respects. Whatever unexpected or not envisaged downtime can cause relevant damages and troubles to end users. It becomes therefore essential to rely on reliable bearings able to meet precise requisites.
Producer of bearings for over 70 years, FLT is one of the most diffused and renowned brands also in the world of transmissions, clutches and axles for agricultural machines and, especially for tractors. For years it has been collaborating, cooperating and supplying the primary manufacturers of axles and transmissions in general in the world, with a constant presence in this sector, providing quality, reliability and trustworthiness of product and process, today necessary more than ever to satisfy the increasingly challenging technical requisites of this market.
«A market – specifies Albertino Calanca, General Manager of FLT & Metals, general branch with headquarters at Anzano del Parco (Como, Italy) of FLT Group– the one of agricultural machines, currently resembling the automotive industry under all respects, in terms of demands, technical requisites and reliability. Market where nowadays the producers of these components are ISO TS16949-certified and, as such, require that likewise their suppliers attain the same certification».
In this context, the most used typologies are ball bearings, taper roller bearings and straight roller bearings. Among them, taper roller bearings are the most widespread not only due to their small sizes but also thanks to their stiffness and their high assembling flexibility.
At the service of wheel hubs
FLT is present in the field of agricultural machines with a product supply available with both dimensional series, both in inches and metric.
«In particular, I would like to highlight – adds Calanca – our taper roller bearings, more used in the wheel hubs for agricultural axles, which sometimes become axles for earth handling machines, too. In this case, the sizes requested by our customers are small but, at the same time, the loading cycles to which bearings are subjected must be supported by an appropriate internal construction, coupled with a high quality and loading capacity».
Especially in the range of these bearings, FLT proposes only executions in reduced precision class, suitable for assembly in set-right.
«Their consumption – still underlines Calanca – is very high, with our customers’ production lines called to drastically reduce the risk of human error and to rise the registration of the torque of taper roller bearings to the limit of “0” defect. Our dedicated calculation programmes, like for instance RomaxDesigner, allow determining all necessary machining tolerances to reach an appropriate and, especially, repetitive (up to 99.73%, editor’s note) axial registration of all the bearings to be assembled, no matter whether you take torque or taper randomly».
In this way, the human intervention, to attain the necessary axial registration of bearings, is replaced by dimensionally identical components, without intermediate adjustment controls. The main characteristics and intrinsic technical peculiarities that such bearings show is that they are relatively thin in proportion to their diameter. For this reason, their heat treatment and the successive machining become the key points to be kept more under control in the entire production process. To keep deformations under control and to avoid the ring deformation during the hardening treatment, FLT is equipped with automatic rotary treatment furnaces instead of the more standard linear belt furnaces.
Fatigue life at the bench testÂ
«To face and to satisfy at best the severe fatigue life requisites underwent by bearings – explains Calanca himself – besides the theoretical verifications with calculation programmes, we can repeat at the test bench all loading conditions to which bearings are subjected. Tests and trials that allow repeating real or factored loads to reduce test time».
In some cases, in the same overall dimensions used, in almost standardized way by those that use axles, you need to have the same bearings but with incremental load capacity. FLT has implemented the most common series of bearings for axles with a cage of reinforced polyamide, instead of formed steel. In this way it is possible to house a higher number of rollers (still keeping the overall dimensions unchanged), and notably increase the loading capacity.
«The cages made of reinforced glass fibre polyamide – adds Calanca – only show some limits concerning operating conditions with temperatures that exceed 100 °C or, when we deal with excessive accelerations, that is to say values surpassing 7g. It is obvious that such limitations are only theoretical since they represent conditions that do not generally occur in axles».
However, the range of bearings proposed and made available by FLT for agricultural transmissions is not limited to the executions intended for the wheel hub but it is completed also by the bearings of pinions and differential gears, by bearings for crown wheels, gearboxes and clutches. As you gradually enter the tractor core, the quality of components and their reliability become more and more important.
«In these machine parts – underlines and ends Albertino Calanca – all proposed technical solutions are accurately studied by FLT technicians and by customers jointly, with standardization processes that undergo very severe courses. All that to grant a constant and, at the same time, repetitive reliability in time. An agricultural machine, in fact, must be considered a high-efficiency operating machine under all respects».
This means that any unexpected and unforeseen downtime can cause troubles and/or damages that are often relevant for end users, generating easily imaginable consequences. A further reason to rely on high-quality components and systems, able to meet severe requisites like those demanded by this industrial sector.
