Operating temperature range The operating temperature of a seated rolling bearing depends on the type of grease used in the bearing, the rubber material of the oil seal, and the internal clearance of the bearing. With the exception of ordinary rolling bearings with seat, heat-resistant components (special symbol D1K2) and cold-resistant components (special symbol D2K2) have also been serialized, so you can select the most suitable bearing for the operating temperature (refer to Table 2.3). However, even if the seated bearing that is most suitable for the operating temperature is selected, since the life of the grease is greatly affected by the temperature, it is necessary to replenish the grease in accordance with the prescribed standards. When the operating temperature and internal clearance of the bearing cause high conduction heat to the shaft or the hollow hole of the shaft passes high-temperature steam, the temperature difference between the inner ring and the outer ring of the bearing becomes larger, which reduces the internal clearance of the bearing, and there is a risk of early damage to the bearing. . According to the temperature difference between the inner ring and the outer ring of the bearing, the reduction in the internal clearance of the bearing can be calculated using formula (7.1). When working under the above conditions, it is necessary to calculate the reduction in the internal clearance of the bearing and correctly select the internal clearance of the bearing. St1u003dα De In the above formula, St1: the reduction in internal clearance caused by the temperature difference between the inner ring and the outer ring of the bearing, mm: the linear expansion coefficient of the bearing steel, 12.5×10-6De: the raceway of the outer ring of the bearing Diameter, mm diameter series 2, XDe ≈ 0.92 D diameter series 3u0026#1048576;u0026#1048576; u0026#1048576;De ≈ 0.9 DD: the nominal outer diameter of the bearing, mmt: the temperature difference between the inner ring and the outer ring of the bearing, ℃. When a seated rolling bearing is used at high temperatures, in addition to the internal clearance of the bearing, sometimes the temperature causes the shaft to elongate in the axial direction and an abnormal axial load is applied to the bearing, which may also cause early damage to the bearing. The countermeasure is to make the shaft as a free end component or the component itself can move in the axial direction (refer to the design of the 9-axis and base).