iglidur® J2 - Material data

Figure 02: Maximum recommended surface pressure dependent on the temperature (46 MPa to +20 °C)
 
X = Temperature [°C]
Y = Load [MPa]

Figure 03: Deformation under load and temperatures
 
X = Load [MPa]
Y = Deformation [%]

Mechanical properties

With increasing temperatures, the compressive strength of iglidur® J2 plain bearings decreases. Fig. 02 clarifies this connection. Maximum recommended surface pressure represents a mechanical material parameter. Tribological conclusions cannot be drawn from it.

 

 
Figure 03 shows the elastic deformation of iglidur® J2 with radial loads. A potential plastic deformation depends, among other things, on the length of exposure.

Maximum surface speed

m/s	Rotary	oscillating	Linear
Constant	0,8	0,7	3
Short-term	1,9	1,1	5

Table 02: Maximum surface speeds

Permitted surface speeds

iglidur® J2 is predominantly suitable for low speeds and dry running conditions; the limit values indicated in Table 02 can only be achieved at very low pressure loads. At the specified speeds, an increase in temperature up to the long-term permitted value can occur due to friction. In practice these limit values are not always reached.

iglidur® J2	Application temperature
Lower	- 50 °C
Upper, long-term	+ 90 °C
Upper, short-term	+ 110 °C
Secure axially in addition	+ 60 °C

Table 03: Temperature limits for iglidur® J2

Temperatures

The temperatures prevailing in the bearing system also have an influence on the bearing wear. The wear increases with rising temperatures, and the influence is especially marked from 90°C temperature onwards. An additional securing is recommended at temperatures higher than +60°C.

iglidur® J2	Dry	Grease	Oil	Water
Coefficients of friction µ	0,11 - 0,27	0,08	0,07	0,04

Table 04: Coefficients of friction for iglidur® J2 against steel (Ra = 1 µm, 50 HRC)

Friction and wear

The coefficient of friction and wear resistance depend on the application parameters (Fig. 04 and 05).

Fig. 06: Wear, rotating application with various shaft materials p = 1 MPa, v = 0,3 m/s
 
X = shaft materials
Y = wear [μm/km]
 
A = Aluminum, hard-anodized
B = machining steel
C = Cf53
D = Cf53, hard chrome-plated
E = St37
F = V2A
G = X90

shaft materials

Friction and wear also depend to a high degree on the reverse partner. Very smooth shafts increase the coefficient of both friction and wear. Figure 06 shows an excerpt of the results of tests with different shaft materials. Fig. 06 shows that when rotating under 1 MPa, iglidur® J2 has the best wear coefficients with machining steel. During dry-running operations, the wear coefficients on other shafts are sometimes far higher.
Unlike many other iglidur® materials, the wear rate is slightly higher with pivoting movements than with rotational movements with otherwise identical parameters (Fig. 07).

Medium	Resistance
Alcohols	+
Hydrocarbons	+
Greases, oils without additives	+
Fuels	+
Diluted acids	0 to -
Strong acids	-
Diluted bases	+
Strong bases	+ to 0

+ resistant      0 conditionally resistant      - non-resistant
 
All specifications at room temperature[+20 °C]
Table 05: Chemical resistance of the iglidur® bearings J2

 

 
Electrical propertiesiglidur® J2 bearings are electrically insulating.

Specific forward resistance	> 1013 Ωcm
Surface resistance	> 1012 Ω

Further properties

Chemical resistance
igligur® J2 bearings are resistant to diluted alkalis and very weak acids as well as to fuels and all kinds of lubricants. The low humidity absorption allows them to be used in wet or humid environment. Plain bearings made from iglidur® J2 are resistant to a wide range of cleaning agents used in the food industry.
 

Radioactive rays iglidur® J2 bearings are radiation resistant up to a radioactive intensity of 3 • 10² Gy.
 

UV-resistant iglidur® J2 bearings change color under the influence of UV rays. However the hardness, compressive strength and the wear resistance of the material do not degrade.
 

VacuumIn application in vacuum, the potentially existent moisture content is degassed. For this reason only the dry iglidur® J2 bearings are suitable for vacuum.

Maximum moisture absorption

by +23 °C/50 % r. F.	0,2 Wt.-%
Max. water absorption	1,3 Wt.-%

Table 06: Humidity absorption of iglidur® J2
 

Diagram 10: Effect of moisture absorption
 
X = Moisture absorption [weight %]
Y = Reduction of inside diameter [%]

Moisture absorption

The humidity absorption of iglidur® J2 bearings amounts to about 0.2 % in standard climatic conditions. The saturation limit in water is 1,3 %. These values are so low that a moisture expansion need to be considered only in extreme cases.

Diameter d1 [mm]	Shaft h9 [mm]	iglidur® J2 E10 [mm]	Housing H7 [mm]
Up to 3	0 - 0,025	+0,014 +0,054	0 +0,010
> 3 to 6	0 - 0,030	+0,020 +0,068	0 +0,012
> 6 to 10	0 - 0,036	+0,025 +0,083	0 +0,015
> 10 to 18	0 - 0,043	+0,032 +0,102	0 +0,018
> 18 to 30	0 - 0,052	+0,040 +0,124	0 +0,021
> 30 to 50	0 - 0,062	+0,050 +0,150	0 +0,025
> 50 to 80	0 - 0,074	+0,060 +0,180	0 +0,030
> 80 to 120	0 - 0,087	+0,072 +0,212	0 +0,035
> 120 to 180	0 - 0,100	+0,085 +0,245	0 +0,040

Table 07: Important tolerances for iglidur® J2 bearings according to ISO 3547-1 after the press-in.

Installation tolerances

iglidur® J2 bearings are standard bearings for shafts with h-tolerance (recommended minimum h9). The bearings are designed for press-fit in a housing with h7 tolerance. After the installation in a housing with nominal diameter, the inner diameter of the bearing automatically adjusts to the E10 tolerance. Compared to the installation tolerance, the inner diameter varies according to moisture absorption.