iglidur® P - Material data

Figure 02: Maximum recommended surface pressure dependent on the temperature (50 MPa to +20 °C)

X = Temperature [°C]
Y = Load [MPa]

Figure 03: Deformation under load and temperatures

X = Load [MPa]
Y = Deformation [m/s]

Mechanical properties

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

Figure 03 shows the elastic deformation of iglidur® Pwith radial loads. Under the maximum recommended surface pressure of 50 MPa, the deformation amounts to less than 4%.

Maximum surface speed

m/s	Rotary	oscillating	Linear
Constant	1	0,7	3
Short-term	2	1,4	4

Table 02: Maximum surface speeds

Permitted surface speeds

The iglidur® P bearings are maintenance-free bearings developed for low to medium surface speeds. The maximum values stated in the Table 02 can be attained only with very low surface pressure. The specified maximum speed is the speed at which the long-term permitted temperature is reached by an increase in heat through friction.

iglidur® P	Application temperature
Lower	-40°C
Upper, long-term	+130°C
Upper, short-term	+200°C
Secure axially in addition	+90°C

Table 03: Temperature limits

Temperatures

Even with its maximum long-term application temperature of +130℃, iglidur® P does not fully approach the values of iglidur® G. The temperatures prevailing in the bearing system also have an influence on the bearing wear. Rising temperatures mean higher wear.

Figure 04: Coefficients of friction dependent on the surface speed, p = 0,75 MPa

X = Surface speed [m/s]
Y = Coefficient of friction μ

Figure 05: Coefficients of friction dependent on the load, v = 0,01 m/s

X = Load [MPa]
Y = Coefficient of friction μ

Friction and wear

The coefficient of friction lowers like the wear resistance with increasing load (Fig. 04 and 05). iglidur® P bearings reach a distinct minimum coefficient of friction for shafts with a surface finish of 0.1 to 0.2 µm. Both smoother and coarser shafts clearly increase the friction.

iglidur® P	Dry	Grease	Oil	Water
Coefficients of friction µ	0,06 - 0,21	0,09	0,04	0,04

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

Figure 06: Wear, rotating application with different shaft materials, p = 1 MPa, v = 0,3 m/s
 
X = Shaft material
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

Figure 06 displays a summary of the results of tests with different shaft materials, which were conducted with iglidur® P plain bearings. In rotating applications, the wear of iglidur® P is very low with CF53 and St37 shafts. In contrast, the bearings are already more worn out than other shaft materials in the lower load range, especially by hard-chromed shafts. At a load of 2 MPa, for example, the Cf53 is superior to the material V2A by six times. The wear rates of low-stressed bearings in pivoting motions with most shaft materials are lower than in rotating applications. For this purpose, the CF53 and hard-chromed shafts prove to be the best counter partners.

Figure 07: Wear with pivoting and rotating applications with Cf53 according to the load
 
X = Load [MPa]
Y = Wear [μm/km]
 
A = Cf53, rotating
B = Cf53, pivoting

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

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

Chemical resistance

iglidur® P bearings have a good resistance against chemicals. They are resistant to most lubricants. The iglidur® P is not affected by most weak organic and inorganic acids.

Radioactive rays

Bearings made of iglidur® P are conditionally usable under radioactive radiation. They are resistant up to a radiation intensity of 5 x 10² Gy.

UV-resistant

iglidur® P bearings have a good resistance against UV radiation.
 

Vacuum

The existent humidity of iglidur® P bearings degasses in the vacuum. The use in vacuum is possible only limitedly.

Electrical properties

iglidur® P bearings are electrically insulating.

Specific forward resistance	> 1013 Ωcm
Surface resistance	> 1012 Ω

Maximum moisture absorption
At +23 °C/50 % r.h.	0,2 % weight
Max. water absorption	0,4 % weight

Table 06: Moisture absorption

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

humidity absorption / moisture absorption

The humidity absorption of iglidur® 200 bearings amounts to about 0,2% in standard climatic conditions. The saturation limit in water is 0,4 %. This minor humidity absorption is clearly below the values of iglidur® G.

Diameter d1 [mm]	Shaft h9 [mm]	iglidur® P 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 iaw. ISO 3547-1 after press-fitting.

Installation tolerances

iglidur® P 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. In certain dimensions the tolerance in dependence on the wall thickness deviates from this (See delivery program )