Conference focus on sealing presentations at two recent tribology events lubricated mechanical face seals with spiral grooves,’ by Y. Wang, H. Yang, Y. Wang, X. Duan and H. Wang (Tiajin Timing Seals Co).
STLE Annual Meeting, Toronto, 17–20 May At the STLE 2004 Annual Meeting there was a panel discussion on ‘Recent advances in sealing technology,’ and two sessions on seals that included a total of total of 10 papers. The panel discussion revealed a wide range of views, from pessimistic to optimistic. On the pessimistic side was the observation that consolidation in the industry and economics leads to an emphasis on being the lowest-cost producer, with very little interest or investment in research and development. The optimistic view was the observation that there are many niche situations where R&D will pay off. Examples include seals and monitoring systems for wind turbines, as well as the general need for an improvement in sealing technology. In the presentation sessions there were seven papers on mechanical seals, and one each on lip seals, labyrinth seals and piston rings. Also relevant to seals R&D was a panel discussion on ‘Surface texturing’. There was great optimism at this discussion, with the view that surface texturing is the way of the future. The Seals I session was a panel discussion on ‘Recent advances in sealing technology’. On the panel were H. Azibert (Chesterton), T.W. Lai (John Crane), R.L. Phillips (Flowserve), J.P. Boylan (Morgan AM&T), I. Green (Georgia Tech), W.D. Marscher (Mechanical Solutions) and A. Paykin (Chicago Rawhide). In the Seals II session, the following papers were presented: •
• • •
‘Automatic feedback control of mechanical gas face seals via clearance control,’ by B.A. Miller, S. Yelma and R.G. Landers (University of Missouri). ‘Near-contact laser surface textured dry gas seals,’ by A. McNickle (Stein Seal Co, USA) and I. Etsion (Technion, Israel). ‘Experimental results for a heat sink mechanical seal,’ by M.A. Hayden and L.S. Stephens (University of Kentucky). ‘Theoretical analysis and design guidelines of oil-film lubricated mechanical face seals with spiral grooves,’ by Y. Wang, J. Wang, H. Yang, N. Jiang, and X. Sun (Tiajin Timing Seals Co, China). ‘Improved adhesion of ultrananocrystalline diamond coatings to SiC mechanical seal surfaces,’ by J.W. Elam, J.A. Carlisle, A. Erdemir, J.N. Hryn and A.M. Kovalchenko (Argonne National Laboratory, USA). ‘Improved running behavior of mechanical seals by the use of innovative ceramic materials,’ by J. Nosowicz and P. Waidner (Burgmann, Germany). ‘Experimental investigations and field applications of oil-film
There were three notable papers in the Seals III session: •
‘A 3-D engineering approach to confirmability analysis of piston rings,’ by V. Dunaevsky (Bendix Commercial Vehicle Systems, USA) and S. Alexandrov (Institute for Problems in Mechanics, Moscow). ‘Rotordynamic coefficients of labyrinth gas seals – general dependency on geometric and physical parameters,’ by K. Kwanka (Thermal Power Systems, Germany). ‘Surface characterization and experimental testing of a radial lip seal,’ by J. Paige and L.S. Stephens (University of Kentucky).
There was also a panel discussion on surface texturing, where four short presentations were of interest: • • • •
‘Surface texture: where do we go from here?,’ by J. Larson-Basse (NSF, USA). ‘EHL modeling of surface textures,’ by D. Zhu (Eaton Corporation, USA). ‘Virtual texturing of surfaces,’ by Q. Wang (Northwestern University, Illinois). ‘Texturing under boundary lubrication for friction control,’ by S. Hsu (NIST, USA).
11th Nordic Symposium on Tribology – Nordtrib, Norway, 1–5 June At the Nordtrib 2004 meeting there were just two papers on seals: •
‘Functionality diagrams for hybrid mechanical seals with silicon nitride rings,’ by J.M. Carrapichano, F.J. Oliveira, J.R. Gomes and R.F. Silva (ISEC, Portugal), U. Aveiro (Portugal) and U. Minho (Portugal). ‘An unsteady mixed soft EHL model, with application to a rotary lip seal,’ by D. Shen and R.F. Salant (Georgia Tech, USA).
Editor’s comment: Thank you to Professor Richard Salant for this update. There appears to have been an increase in sealing interests at STLE compared with 2003. I believe that the real feature of Nordtrib is the venue and a mini-cruise.
SpringSafe fixes and frees the spring on NBR and HNBR radial lip seals Walkersele radial lip seals can now be supplied with the lipenergizing spring encased in elastomer and cured in position using the new SpringSafe method from James Walker. This development is intended to give users confidence that the spring is located correctly during seal installation, and cannot readily be dislodged to create secondary damage if a shaft or bearing runs beyond its operating limit. The encasing technique developed by James Walker allows each
Sealing Technology August 2004
spring coil to move freely, for efficient sealing under eccentric operating conditions. In addition, it helps to protect the spring against chemical and abrasive attack. The seal is also said to be easier to install with the spring fixed in position, especially when fitting in a blind housing. This can contribute to reducing downtime, both directly because of the easier fitting, and indirectly because there is less chance of a misplaced spring. Walkersele lip seals are used on heavy-duty industrial
equipment to retain lubricants in a bearing assembly and exclude contaminants. Typical applications include rolling mills, marine propulsion systems, gearboxes and transmissions, wind turbines, process mixers and rotary kilns. The SpringSafe is currently available on endless-type seals for shaft diameters of 250 mm and above. It is applicable to Walkersele D6 and D7 designs where the seals are molded in nitrile (NBR) or hydrogenatednitrile (HNBR) elastomers,
including the Elast-O-Lion and Ultraglide grades. Contact: James Walker & Co Ltd, 1 Millennium Gate, Westmere Drive, Crewe CW1 6AY, UK. Tel: +44 1270 536000, Fax: +44 1270 536100, Email: technical.crewe@ jameswalker.co.uk, Web: www.jameswalker.co.uk Editor’s comment: This is an interesting and useful development. On large equipment with difficult access, ensuring retention of the spring can be a particular problem.