Sealing products extended for rotary shafts

Citation

(1998), "Sealing products extended for rotary shafts", Industrial Lubrication and Tribology, Vol. 50 No. 6. https://doi.org/10.1108/ilt.1998.01850fad.001

Sealing products extended for rotary shafts

Sealing products extended for rotary shafts

Keywords: Sealing, Seals

The range of sealing products offered by Dichtomatik Ltd have now been considerably extended by the inclusion of rotary shaft oil seals (see Plate 1). These include industry standard metal and rubber cased seals available in both imperial and metric sizes.

Conventional compound Nitrile rubber seals can be supplied in different degrees of hardness, together with high temperature Viton and PTFE versions. They are suitable for use with a wide range of generally used fuel, engine and machine oils, as well as waterless fluids, water and Lyes over a temperature range of ­40ºC to +170ºC.

Three basic standard seal types are available called WA, WB and WC, all usually fitted with garter springs to provide enhanced seal lip performance. The type WA seal has a rubber elastomer outer covering to the metal insert. This tolerates housing bore roughness as well as thermal expansion. It eliminates shaft fretting corrosion and prevents housing bore damage during frequent seal replacement. This seal is ideal for gaseous and liquid media sealing.

The type WB seals are metallic cased for easier fitting. Type WC seals are also metallic cased with an additional reinforcing cap and are designed for rougher applications and larger sizes.

All seal types can also be supplied with dust lips for additional protection against dirt and corrosion. The WA and WB types can also be supplied without garter springs for moderate service applications or with dual seal lip configurations where sealing and separation of two different media are required.

Plate 1Selection of typical oil seals for rotary shaft applications which can now be supplied by Dichtomatik Ltd

A further range of special adaptations can be provided to give enhanced sealing or protection qualities. These include twin dust lips and rifling to the elastomer surface. This rifling can be used on the seal face and dust lip, either clockwise or anti-clockwise or a combination providing alternate rifling. Type WA seals can also be supplied with grooves to the dust lip and/or outer casing.

For larger shaft diameters a split seal configuration can be supplied in either elastomer or PTFE. These do not incorporate metal reinforcement but are supplied with garter springs.

A wide range of seals can be supplied from stock in various combinations of shaft, housing diameter and seal width dimensions. Shaft diameters from 6 to 490mm metric sizes can be accommodated, with imperial sizes ranging from 0.25in. to 12.25in. diameter including some 1/16in. increments.

In addition to the range of shaft seals, Dichtomatik Ltd also claim to be one of the largest stockholders of "O" rings to UK industry. The range covers both standard and non-standard metric and imperial products with wide design options for size, materials and compound hardness. With literally millions of "O" rings being available at any time, the company also offers a 100 per cent quality check covering surface finish, cross section and internal diameter.

Their products are precision moulded to exacting tolerances and conform to current British, European and International standards. They are designed primarily for static sealing but also some dynamic fluid applications, suitable for use in a wide range of general engineering products and including both food grade and low temperature requirements.

The standard catalogued range covers "O" rings with inside diameter dimensions from 1.00 to 670mm in size and cross-section dimensions from 1.00 to 670mm. The actual products held in stock, however, cover a range of seals at least 50 per cent greater than catalogued items, providing a much wider choice of both size and materials. Nitrile 80 and 90 versions are available as well as the standard nitrile 70 materials, together with high temperature Viton, EPDM and Silicone variations.

For general service and repair requirements, boxed sets of "O" rings can be supplied in imperial and metric sizes, together with products complying with French standards.

For special sealing requirements, "O" rings normally in excess of 500mm inner diameter can also be supplied manufactured from extruded cord with a bonded or vulcanised joint. These are suitable usually for less stringent sealing applications and can be supplied in both standard and special compounds.

Rubber cord can be supplied up to 100 metres in length in standard compounds of NB70 Silicone and Viton. Cord diameters range from 1.78mm to 30mm.

Further information is available on request from Dichtomatik Ltd, Unit 21, Trent Lane Industrial Estate, Castle Donington, Derby DE74 2NP. Tel: +44 (0)7000 467464; Fax: +44 (0)7000 426973.