iglidur plain bearings - Temperatures

Overview of the lower, long-term and short-term upper application temperatures [°C]

Plain bearings made of high-performance polymers are often underestimated, particularly with regard to the permissible temperatures. The continuous operating temperature is often stated in the literature. The continuous operating temperature is the highest temperature under prolonged heat exposure that the plastic can withstand without mechanical load for a certain period of time without the reduction in the tensile strength of the material falling below or exceeding a specified value. However, this standardised test only provides a less relevant characteristic value, as bearings are almost always subject to a load. The application temperatures of the materials are more informative.

Application temperatures
The lower application temperature is the temperature below which the material becomes so stiff and hard that it is too brittle for normal applications. The upper, continuous application temperature is the temperature that the material can withstand over a longer period of time without the specifications changing significantly.
The upper, short-term application temperature is the temperature above which the material becomes so soft that it can only withstand very low external loads.

In this context, "short-term" means a period of a few minutes. If the plain bearings are moved axially or the forces can have an axial effect on the bearing, there is a risk that the bearing will move out of the hole even earlier. In these cases, the bearing bushes must be specially secured in addition to being pressed in.

Table 01 shows the temperature limit above which the plain bearings must be secured in the hole, even at low axial forces. The greater the forces, the more likely it is that such securing should be considered.

Temperature and load
diagram. 02 and 03 show the maximum recommended surface pressure [p] of the iglidur® bearings above the temperature. This value decreases continuously as the temperature rises.
When using plain bearings, it should be noted that the bearing temperature may be higher than the ambient temperature due to friction.

Thermal expansion coefficient
The thermal linear expansion of polymers is around 10 to 20 times higher than that of metals. In contrast to metals, it is also not linear for plastics. The thermal expansion coefficient of the iglidur® bearings is an important reason for the required bearing clearance. Within the limits of the respective intended application temperatures, there is no jamming of the shaft in the bearing. The expansion coefficients of the iglidur® bearings were examined for important temperature ranges and are specified in the material table in the individual chapters.

Material	Temp. [°C]
iglidur G	+100
iglidur J	+60
iglidur M250	+60
iglidur W300	+60
iglidur X	+135
iglidur K	+70
iglidur P	+90
iglidur GLW	+80
iglidur J260	+80
iglidur J3	+60
iglidur J350	+150
iglidur L250	+55
iglidur R	+50
iglidur J200	+60
iglidur D	+50
iglidur V400	+100
iglidur X6	+160
iglidur Z	+145
iglidur® UW500	+150
iglidur H	+120
iglidur H1	+80
iglidur H370	+100
iglidur H2	+110
iglidur A180	+60
iglidur A200	+50
iglidur A350	+140
iglidur A500	+130
iglidur A290	+110
iglidur T220	+50
iglidur F	+105
iglidur H4	+110
iglidur Q	+50
iglidur UW	+80
iglidur B	+50
iglidur C	+40