Page 75: of Maritime Reporter Magazine (November 1985)
ported properly through the bearing so that it produces a continuous film between the bearing and the shaft, it can eliminate almost all contact between the two. The creation and maintenance of that film is the function of the critical design of the bearing configuration.
Rubber, on the other hand, brings to the bearing equation its own set of desirable traits, principally the fact that when it is sufficiently wet- ted, it has a naturally lower coeffi- cient of friction than other tradi- tional bearing materials.
The final factor in the bearing equation is design, which optimizes the natural characteristics of the rubber and water to produce a bear- ing system that achieves maximum levels of attainment in the reduction of friction temperature, and wear.
The Cutless brand bearing config- uration provides a rubber surface designed to provide, in a perfect cir- cle, a series of alternating "water wedges" and "water grooves." The water grooves serve as reservoirs through which incoming water is the lubricating coolant; the outgoing water functions to flush out dirt and potentially damaging grit.
The water grooves approach the surface of the shaft in a very exact and narrow angle, which causes a volume of water from each groove to form a wedge of water between the bearing and the shaft surfaces.
These wedges of water in turn pro- duce a continuous film of lubricat- ing water that keeps that shaft and the bearing separated, a condition that obviously keeps wear on both parts to a minimum.
The ability of rubber to deform and rebound accommodates load changes from the shaft and permits the bearing to continue to perform effectively even though the shaft may be bent or misaligned.
For bearings designed to fit shafts with outside diameters greater than 6V2 inches, such as those on the
Icoa, BFGoodrich/Moffitt has de- signed a segmental type bearing that produces the same bearing sur- face configuration and performance as a full molded bearing. In the seg- mental bearing, longitudinal staves composed of thin rubber facings molded to noncorroding, high mo- lecular weight polyethylene backing strips (Romor® brand staves), are precision made to fit into matching, trapezoidal slots, machined into the bearing housing. With all staves in place, the bearing surface provides the same "water groove/water wedge" profile. A major advantage of the segmental type bearing is the fact that individual staves can be replaced one or more at a time.
The dredge Icoa is but one of the many vessels that have employed these water-lubricated rubber bear- ings. But this vessel, during her nearly quarter century on the Ori- noco, has served as a hostile proving ground, and as the "necessity of invention" for a number of Cutless bearing refinements.
For a copy of a brochure contain- ing complete data describing the
Cutless bearing line,
Circle 17 on Reader Service Card
November, 1985 77
Free Brochure On
An informative, four-color bro- chure explaining how automated project management can help keep projects on-time and within budget is now available from Systonetics,
Inc., Fullerton, Calif.
This colorful publication details
Towing and docking in rough seas is much safer and easier with
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The Compensator provides the rope with the elasticity essential to absorbing enormous shock loads. Based on Murdock's ad- vanced elastomeric technology, the
Compensator maintains a constant tension on the rope. It instantly pays out rope when shock loads develop, then retracts rope when the load subsides. There's no opportunity for slack to develop.
This eliminates the danger of a sudden shock load causing the rope to snap. the importance of combining up-to- the-minute information with total visibility for effective project con- trol. It gives brief history of how
Systonetics pioneered the convert- ing of computer-generated informa- tion into easy-to-read project gra- phics (networks, gantt barcharts and cost/resource graphs) and re- ports.
Furthermore, the brochure pre- sents Systonetics' innovative soft- ware systems: EZPERT—what is said to be the recognized standard
Tension forces generated by the compensator and the length of rope travel it allows are easily ad- justable. Because it's a passive for project graphics systems; VI-
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The systems are defined in clear text, which is accompanied by colorful graphics.
In addition, a convenient, pre- paid "information request" post- card is included in the brochure.
For a free copy of this interesting and informative brochure,
Circle 79 on Reader Service Card system, there's no maintenance other than occasional lubrication of the bearings.
The compensator is easy to install. Aboard ships, it usually is mounted between the winch and fairlead — without altering the ves- sel's winching system. It also can be installed on docks and single- point mooring systems.
Learn more about how Mur- dock's Rope Tension Compensator can prevent disastrous mooring line breaks. Write or call Murdock today.
MURDOCK ENGINEERING COMPANY
RO. Box 152278, Irving, Texas 75015 (214) 790-1122, TWX 910-860-5901, Telex 792996
In Europe contact: Gray Mackenzie, 3rd Floor, Royalty House 72-74 Dean Street, London W1V 5HB Telephone: 01-439 7252, Telex: 25697
Circle 250 on Reader Service Card
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