Duramax Marine® is the world leader in the design and manufacture of environmentally friendly water lubricated bearings for use in marine propulsion systems, cutter-head dredges, hydroelectric turbines and Industrial pump applications. In addition to water lubricated bearings they design and manufacture advanced propulsion shaft seal systems, heat exchange systems and impact protection systems.
Johnson Cutless®, Johnson Demountable and Romor® stern tube and strut bearings are known worldwide for their high quality and dependable performance. Duramax water lubricated stern tube bearings are used in more military and commercial marine vessels than any other.
They engineer bearing and seal systems that will perform in the most demanding marine and industrial applications and offer advanced designs when applications require a more engineered solution.
Their team of heat transfer scientists continue to research and design new state of the art heat exchange solutions for today's marine diesel engines. Their engineers use best in class modelling techniques that test and validate heat transfer advancements utilizing a full-scale water tunnel test installation.
The Cutless brand is the most recognized water lubricated marine bearing around the world. Johnson Cutless bearing was the first and continues to be the only bearing to meet all MIL-DTL-17901C Class II requirements.
Duramax Marine high-quality standards, unmatched marine experience, and decades of water-lubricated rubber bearing research have resulted in performance records that other manufacturers only promise.
Johnson Cutless bearings are engineered with a proprietary formulation of extremely tough chemical and oil resistant nitrile rubber polymer lining, molded and firmly bonded into a naval brass or non-metallic shell. Grooves run the entire length of the rubber lining allowing for maximum lubricating water flow and dissipation of frictional heat.
DuraBlue water-lubricated stern tube bearings are manufactured using a unique synthetic reinforced composite that incorporates solid lubricants for superior operation and outstanding wear life in blue water applications.
The composite resin matrix was designed to withstand the rigors of seawater operation and frictional heat generated when used in stern tube propulsion systems.
DuraBlue is dimensionally stable, has a very low coefficient of expansion in extremely cold or tropical regions. DuraBlue is designed to tolerate edge loading and misalignment even with the heaviest loads. It is chemical and corrosion resistant and will not cause corrosion to housing.
ROMOR I was engineered for low friction and noise particularly at minimal journal velocities. It was field tested on the trident submarine and the results were outstanding – "no bearing-initiated hull noise at any speed". The potential for squeal and stick-slip was virtually eliminated, for smoother operation. ROMOR I low friction characteristics results in better energy efficiency and a remarkable increase in bearing and shaft life.
ROMOR I technology developed for the military is available in a radius-backed locking stave design for use in commercial marine round-bore stern tubes. It's the ecological answer that will help you meet the marine industries requirements for a clean new world, while dramatically cutting maintenance time and costs.
The Duramax Shaft Seal Systems are available for shafts from 3/4 inch to 6-3/4 inch diameter. The design features of this system eliminate problems that other systems experience, and with no lip seals or packing to change there is no maintenance. It is easy to install, with no need for constant adjustments once properly installed. Removal and replacement of the system is simple.
The DryMax Stern Tube Seal System was designed, built and tested by Duramax Marine in the USA. The seal is a water-lubricated axial shaft seal system constructed of the highest quality materials which have been engineered to deliver long service life.
The DryMax Shaft Seal is a reliable system that uses no grease or oil and is easy to install and maintain. It is a great addition to a full line of proven and reliable marine products developed by Duramax Marine and engineered to protect the environment
Johnson heavy-duty stuffing box is engineered and built to seal out seawater and give unmatched protection for your propulsion system. Its robust construction, highest quality alloys and precision machining gives it the ability to withstand long service life at sea. It's not uncommon for a Johnson Heavy-Duty Stuffing Box to last the life of the vessel.