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Precision Bearings Keep Hydraulic Systems Running

Release time : 2015-06-13 10:39:09
Hydraulic drives and pumps require precision bearings and seals that are reliable, efficient and able to withstand the most demanding operating conditions. Hydraulic drives and pumps are hard at work in almost every conceivable area of manufacturing, often in the most critical, demanding applications, from the oil and gas industry, chemicals and pharmaceuticals, through to water, sewerage, metals processing, food and beverage The components inside these hydraulic drives and pumps need to be reliable, energy efficient and able to withstand often very harsh operating environments. A gear pump, for example, is used in almost all industrial sectors, supplying coolants and foodstuffs or keeping hydraulic systems in motion. They are also found in municipal vehicles, mobile hydraulic equipment and agricultural machinery. Schaeffler's Fluid Technology division offers a diverse range of bearings and other precision components for hydraulic drives and pumps. This includes roller bearings, needle roller bearings, plain and spherical bearings, fine blanked parts, inner rings, locknuts, ball bearings, steel seals, pistons and valves. For gear pumps, Schaeffler offers its Permaglide plain bearings or high quality needle roller bearings, ensuring that the gears perform with almost zero losses. The supply medium is often used as the lubricant for the bearings. For the supply of fluids with low lubrication characteristics, needle roller bearings are increasingly used rather than plain bearings in order to maximise the life of the gear pump. In addition, higher speeds can be achieved if less heat is generated from the bearings. Hydrostatic gearboxes transfer continuously variable driving force in quad bikes, sit-on lawnmowers, tractors and off-road vehicles. As well as rolling bearings and plain bearings, Schaeffler offers its INA-branded precision parts, including deep drawn hollow pistons, valves and fine blanked components. "Schaeffler's precision bearings can be found in every type of hydraulic pump or valve, whether the application is drinking water, hot water, cooling water, fire fighting, aggressive or abrasive media, wastewater disposal or high viscosity media", comments Dr Steve Lacey, Engineering Manager at Schaeffler UK. "The pump speed and load often determine whether ball bearings, cylindrical roller bearings, radial spherical roller bearings or plain bearings are selected for the application". "However, because there are many different pump designs, we have developed a wide range of bearing types, designs, cage variants and seals". "We can customise the bearing for the application if necessary and we prefer to work closely with the customer's design engineers at an early stage of their design process if possible", he continues. Schaeffler's premium X-life brand of INA and FAG bearings are optimised for the application. Bearing characteristics of X-life products are low noise, maintenance-free, high load carrying capacity, resulting in an improved price-performance ratio. High torque motors are often specified for applications in which abrupt stops or reverse motion occur, including agricultural machinery, crushers, feed devices, rolling mills, paper mills and bulk handling machines. High torque motors are used rather than conventional gearbox and motors where there are extremely high torques present (as high as 1.4MNm) and harsh operating conditions. As Dr Lacey explains: "High torque motors typically offer low startup friction and stick-slip free motion at low speeds". "Our premium quality cylindrical roller bearings with special coatings, inner rings and high precision locknuts, contribute enormously to the functional reliability of these motors". Schaeffler bearings are also specified for bent axis pumps and motors. Ready-to-mount functional units, bent axis motors are used in hydraulic systems to generate pressure. The stroke motion of the axially oscillating pistons is generated by the main output axis, which is bent towards the rotor axis. "We manufacture geometrically accurate steel seals with split butt joints for designs with either centred or eccentric crowned outer diameters, as well as for other contours", states Dr Lacey. "Our product range also includes high precision control discs and other fine blanked parts with consistently accurate contours and smooth, perpendicular cut surfaces that can also be made from metal composites". Schaeffler's INA-branded DRG steel seals are characterised by their low press-on force, minimal leakage, low wear, high resistance to abrasion, and their resistance to oil and temperature.