iglide® P - Material data

Maximum surface speed

fpm	Rotating	Oscillating	Linear
Constant	196	137	590
Short-term	393	275	787

Permitted surface speeds

The iglide® P bearings are maintenance-free bearings developed for low to medium surface speeds. The maximum values stated in the Table 16.2 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.

Figure 16.3: Maximum recommended surface pressure dependent on the temperature

Temperatures

Even with its maximum long-term application temperature of 248° F (120° C), iglide® P does not approach the values of iglide® G. With a short-term permitted maximum temperature of 392° F (200° C), a paint drying process is still possible without further load.

With increasing temperatures, the compressive strength of iglide® P bearings decreases. Fig. 16.3 clarifies this connection.

The temperatures prevailing in the bearing system also have an influence on the bearing wear. Rising temperatures mean higher wear.

Temperature limits

iglide® P	Application temperature
Lower	- 40 °F
Upper, long-term	+ 266 °F
Upper, short-term	+ 392 °F

Figure 2.4: Coefficients of friction dependent on the surface speed, p = 109 psi (0.75 Mpa)

Friction and wear

The coefficient of friction alters like the wear resistance with increasing load. For iglide® P the coefficient of friction slightly increases with increasing speed. Figure 16.5 shows how strongly the coefficient of friction drops with increasing load. From about 870 psi (6 MPa), the coefficient of friction is already below 0.1.

iglide® 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.

Coefficients of friction for iglide® P against steel
(Ra = 1 µm, 50 HRC)

iglide® P	Dry	Fat	Oil	Water
Coefficients of friction µ	0.06 - 0.21	0.09	0.04	0.04

Fig. 2.7: Wear, rotating application with different shaft materials, load p = 109 psi (0.75 Mpa), v = 98.5 fpm (0.5 m/s)

Figure 16.8: Wear with various shaft materials in the rotating operation dependent on the load

Shaft materials

The diagrams 16.7 and 16.10 display a summary of the results of tests with different shaft materials conducted with bearings made of iglide® P.

In rotating applications, the wear of iglide® P is very low with Cf53 and St37 shafts. In contrast, the bearings wear out with both V2A shafts and hard-chromed shafts more strongly than with other shaft materials even in the lower load range; for example, the Cf53 outclasses the material V2A sixfold at a load of 290 psi (2 MPa).

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. Even the V2A shafts that are not so suitable for rotations are excellent for the pivoting application.

Please contact us in case the shaft material scheduled by you is not included in this diagram.

Important tolerances for iglide® P bearings according to ISO 3547-1 after the press-fit.

Diameter d1 [inch]	Shaft h9 [inch]	iglide® P E10 [inch]
Up to 0.019685	0 - 0.0009846	+0.000551 + 0.0021260
> 0.1181 to 0.2362	0 - 0.0011811	+0.000787 + 0.0026772
> 0.2362 to 0.3937	0 - 0.0014173	+0.000984 + 0.0032677
> 0.3937 to 0.7087	0 - 0.0016929	+0.001260 + 0.0040157
> 0.7087 to 1.1811	0 - 0.0020472	+0.001574 + 0.0048819
> 1.1811 to 1.9685	0 - 0.0024409	+0.001969 + 0.0059055

Installation tolerances

iglide® P bearings are standard bearings for shafts with h-tolerance (recommended minimum h9).

After the installation in a housing bore with H7 tolerance, the inner diameter of the bearing automatically adjusts to the E10 tolerance.

Medium	Resistance
Alcohol	+
Hydrocarbons	-
Fats, oils, without additives	+
Fuels	+
Diluted acids	0
Strong acids	-
Diluted bases	-
Strong bases	-

+ resistant      0 conditionally resistant      - non-resistant

Figure 16.11: Influence of humidity absorption of iglide® P bearings

Electrical properties

Specific forward resistance	> 1013 Ωcm
Surface resistance	> 1012 Ω

Chemical resistance

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

The humidity absorption of iglide® P 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 iglide® G300.

Radioactive rays

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

UV-resistant

iglide® P bearings provide a comparably good UV resistance.

Vacuum

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

Electrical properties

iglide® P bearings are electrically insulating.