Deep groove ball bearings for high-temperature applications

What often used to have to be designed as custom-made bearings is now available in Findling Wälzlager’s standard range on short notice.

Operating conditions with high temperatures place particular demands on bearing technology because the volume of the roller bearing can increase due to the changing material structure. When dimensions vary in the bearing, the operating clearance decreases, which impairs the machine element’s function. Lubricants and seals are also subjected to thermal loads. The material characteristics and dimensions of all components of high-temperature roller bearings must be geared toward this accordingly. This is the case for the new additions to Findling’s product range. The 2RS VT200 series is one of them. The deep groove ball bearings sealed with resistant Viton on both sides are suitable for applications with operating temperatures of -30 °C to 200 °C and low to high-speed applications, for example in electric fans or heater fans, as well as in all kinds of ovens and grilling devices. The chromium steel (AISI 52100 100 100Cr6, 1.3505) roller bearings have excellent surface quality, a high level of hardness and a high load carrying capacity as well as excellent wear resistance and form stability. In order to achieve maximum mechanical strength, they are fully hardened. The bearings are in tolerance class P6 and bearing clearance group C4 for interference fit of the bearing rings and are suitable for a larger temperature differential between the inner and outer ring. Various sizes with hole diameters of between 3 and 75 millimeters are available for a wide range of applications in the 68, 69, 60, 62 and 63 series. 2RS VT250, which guarantees a reliable seal up to 250 °C, is being added to the series. The functionality of the bearings must be ensured at these temperatures, for example in waffle baking machines.

Resistance in a compact size
Findling’s HT280 bearing series with PTFE lubricant has solutions for operating temperatures of up to 280 °C and for hole diameters of 3 to 100 millimeters for both delicate and performance-oriented applications. The high-temperature bearings with lifetime lubrication are particularly recommended for difficult-to-access machinery and plant locations where maintenance is comparatively complicated or for applications with high hygiene requirements. The use of conventional bearing technology can lead to disappointing downtimes under the particular stresses caused by high temperatures and cleaning with high-pressure washers, as in the food industry. This is a key economic factor because downtimes in production are very costly. The surfaces of the bearing components are manganese-phosphated for protection against corrosion but also to improve the running characteristics.

High-performance for extreme situations
The maintenance-free bearings of the HT350GR series can handle even more extreme operating conditions. They cover a temperature range of -50 °C to 350 °C. The 60, 62, 63 series are available, in 16 sizes each with hole diameters of 10 to 75 millimeters. The rolling elements are guided in a special graphite cage, which simultaneously acts as a lubrication system. During operation, tiny amounts of graphite are rubbed off which are enough to lubricate the bearing. The bearing interior is protected by the sheet metal dust shields on both sides that have gap-type seals. The ZZ design is a seal variant that offers normal protection against dirt and spray water in a wide range of temperatures. The seal washers are also manganese-phosphated in addition to the bearing components. Since the maximum bearing load is significantly reduced at high temperatures, a full complement and thus non-cage series is also available. In addition to the diverse standard range, which is available ex stock on short notice, Findling Wälzlager also creates custom bearings according to customer specifications.