Devatex dry bearings

Citation

(1998), "Devatex dry bearings", Industrial Lubrication and Tribology, Vol. 50 No. 1. https://doi.org/10.1108/ilt.1998.01850aad.010

Devatex dry bearings

Devatex dry bearings

Glacier GmbH Deva Werke has produced a new maintenance-free dry bearing material aimed at the high dynamically loaded bearing market. Called Devatex the bearing consists of a resin impregnated spirally wound glass fibre backing lined with high strength polymer fibres embedded in a PTFE filled epoxy resin bearing surface.

Glacier Devatex is a new machinable, maintenance-free bearing material for high dynamic load applications

If this sounds like Gar-max, a Garlock material also made by Deva, then you would be right. The main difference seems to be that Gar-max has a bearing surface of PTFE fibres as well as high strength polymer fibres embedded in a graphite filled epoxy resin layer. The special cross-winding manufacturing technique that builds up the bearing material used for both Devatex and Gar-max prevents delamination of the bearing surface from the backing, referred to as the carrier layer.

Performance and mechanical properties claimed for both materials are identical apart from Devatex having a slightly higher static load capacity of 220 MPa and higher density of 2.01 g/cm³. Devatex can tolerate misalignment better. Devatex was also suitable for use against softer shaft materials, 35 HRC compared to the 50 HRC recommended for Gar-max. Lower harnesses were permissible in abrasive-free environments. A major advantage of Devatex is that it can be finish machined on both the outside and inside diameters.

Bushes are offered in the bore size range of 16 to 200mm, made in accordance with the DIN 1850 part 1 standard. Wall thicknesses are from 2 to 10mm.

Usually for polymer bearings the thermal expansion coefficient is only slightly higher, at 13 x 10⁶/K, than that of steel's 11 micrometres per metre per degree C.

Devatex is for use where there are high loads, up to 120 MPa dry or 140 MPa with mixed lubrication, and low speeds, up to 0.2 m/s (0.3 lubricated). Maximum PV values (load times speed) are 1.8 W/mm² or MPa x m/s dry at 0.2 m/s and 0.4 MPa x m/s at maximum load. Ten per cent higher PVs are acceptable with lubrication (see Figure 1).

Typical applications are in construction and earth moving equipment, conveyors, railway couplings, water turbine pivot bearings, valves and the chemical industry.

Contact: Glacier Industrial Bearings, Glacier Vandervell Limited, Kilmarnock KA1 3NA, Scotland. Tel: 01563 539999; Fax: 01563 571426.

Figure 1 PV values with lubrication