Self-lubricating bearings

High-performance grease A new grease from Rocol, BRB 1200, based on a blend of synthetic and petroleum products, is proving to be effective for solving lubrication problems in hostile environments. F o r example at Tarmac Roadstone Holdings Ltd reductions in time spent on high temperature lubrication have been made by using it. There are two units at the Tarmac plant each consisting o f a mixer, check-weigher, batch heater and a batch heater mixer. Slag is carried by conveyor into the check-weigh hoppers and then discharged into the batch heater. After drying by a flame j e t unit each batch is delivered b y chute into the mixer where it is coated with hot tar or bitumen. The flame blasting into the batch heater creates temperatures up to 90°C at the flap-door of the check weigher and thus the selection of an effective lubricant is of paramount importance. Tarmac found that when using conventional greases, the shaft of the flap door had to be greased at least once a day, as the grease melted out and tended to become sticky, seize up the flap door, and cause costly production stoppages. At this stage, BRB 1200 was tried. This grease is designed to operate over a wide temperature range, - 30°C to 200°C, and provides oxidation and corrosion protection. With the introduction of BRB 1200 lubrication has been necessary only once a week and production stoppages due to the need to lubricate these points have been eliminated. Rocol Ltd, Rocol House, Swillington, Leeds LS26 8BS

Self-tapping thread on grease nipple A grease nipple with a self-tapping taper thread is now being marketed by Kingfisher Ltd. The nipple has a ¼ in diameter X 28 thread/in (1 in = 25.4 mm) taper thread which can be screwed into a 6 mm hole in most metals. Use of the nipple c u t s out a tapping operation and when a replacement is necessary a ¼ in UNF nipple can be used. Kingfisher (Lubrication) Ltd, Meanwood Road, Leeds LS2 2BI

Self-lubricating bearings The RHP Transmission Bearings Division has introduced a range of Self-Lube bearings called the Mustard Line. The whole range of sealed, aligning, regreasable, bearing units has been rationalized, and the preferred range will give faster delivery and preferential prices. The Mustard Line includes inch and metric grub screw locking pillow blocks and flange units with bore sizes from ¾ in (20 mm) to 3 in (75 ram).

equipment, the information is fed into the computer. In addition to preparing a complete lubrication and maintenance schedule, any o f four optional reports can also be produced by the computer: A complete listing of all equipment and parts Feedback reports listing lubrication and maintenance activities that were scheduled to be done but were not completed Further action reports listing all unusual problems encountered by different maintenance skills while performing their normal activities Skill allocation reports outlining the man-hours available per skill, per day, per shift, and the work load scheduled for each skill per day, per shift. Texaco Inc, 21O0 Hunters Point Ave, Long Island City, NY 11101, USA

Glass-filled ptfe sealing rings Piston rings of glass-filled ptfe fluorocarbon resin are being used in the Borg Warner Model 12 automatic transmission of the 4.2 litre Jaguar XJ6, and Jaguar Series 3 E-type, the Daimler Sovereign, and on the main piston of the power-assisted steering system of the Daimler Limousine. In addition, seal rings of ptfe are being used on valve sleeves in the power-assisted steering equipment of the Jaguar XJ6, Jaguar Series 3 E-type, Daimler Sovereign, and Daimler Limousine models. Fig 8 shows four seal rings of glass-filled ptfe on a valve sleeve. Du Pont say that the piston rings of filled Teflon ptfefluorocarbon resin have been in the power-steering units to improve sealing. Wear and friction are also reduced, allowing smoother steering. Although the rings ptfe were originally used because of these functional advantages, they can now compete on cost with metal rings as a consequence of improved manufacturing techniques. Ptfe is inert in oils, fuels and lubricants and has a maximum continuous servace temperature of 260 C. It absorbs practically no moisture and its non-stick properties, coupled with a very low coefficient of friction, eliminate the risk of stick-slip. The natural stretch qualities of ptfe allow jointless seals, which are a big improvement over the previous type from the points of view of both sealing and noise reduction. •

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Du Pont Company (United Kingdom) Limited, 18 Bream's Buildings, Fetter Lane, London EC4,

Transmission Bearings Division, Ransome Hoffmann Pollard Ltd, Ferrybridge, Knottingley, Yorkshire, England

Computerized lubrication and maintenance schedules A computerized system to schedule plant lubrication and maintenance has been introduced by Texaco. The system, called Computex can develop multiple schedules based on individual craft skills, date o f required service, and work shift responsible. The software package is written in C o m m o n Business Orientated Language (COBOL) for third generation computers. Basic information necessary as input to the computer is supplied jointly by Texaco and the user through a lubrication study. Once lubrication and maintenance needs are established for each piece of

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