Unit 22-23, Palghar, India - 401 208 +91 8369475818
GMP is one of the world’s most trusted names and leading manufacturer in the marine industry for over 47 years. Our bearings are now sold and used in more than 60 countries. Our bearings are used in rudder, shaft and stern gear applications for all types of marine vessels from naval ships, cargo/container ships, tankers, ocean liners, luxury yachts to harbor tugboats, trawlers and coastal fishing boats.
Our high quality standards, unmatched marine experience, backward integration, In-house production facilities and decades of water-lubricated rubber bearing research has resulted in offering Marine bearings with performance and endurance that lasts.
With continuing research and advancements in product technology, GMP Marine Cutlass bearings now exceed US Navy specifications in critical parameters like Tensile strength, elongation and bond strength.
GMP Marine Cutlass Rubber bearings are made to the highest quality standards, in materials, workmanship and dimensional accuracy (Clearance and tolerance is as per U.S. Navy Standard,). Our products meet or exceed MIL-DTL-17901C Class II requirements.
Our bearings have proved its mettle by operating in the toughest conditions ranging from the arctic to the tropics, in shallow waters as well as high seas.
Our standard bearings cover a wide range of shaft diameters from 25mm to 400mm.
All GMP bearings are lined with a proprietary formulation of extremely tough chemical and oil resistant Nitrile rubber perfected over decades of research and development. The rubber is extremely tough and resistant to swelling, as well as exposure to chemicals and oil. This Nitrile rubber compound is molded and bonded to metal (Naval Brass) or non-metallic shell. The bond strength between the shell and Nitrile rubber lining is an industry leading 235 PSI (16.5 Kg/sq. cm)
The inner groove design of GMP bearings combined with proprietary Nitrile rubber lining create a hydrodynamic lubricating film to separate the bearing surface and the shaft even at low shaft speeds. The unique shape of our bearing grooves is designed for maximum lubricating water flow and dissipation of heat. Abrasive grit is flushed out through these grooves, protecting the shaft as well as the bearings from damage.
This helps to reduce wear on the bearing surfaces in environments with high sand and other abrasive particles, as found in shallow water.
The bearing is designed to let these abrasive particles pass over its surface and into the grooves where it is flushed out by water feed pressure. This system prevents these particles from getting embedded into the bearing surface and causing severe wear on the propeller shaft.
Most manufacturers use centreless grinding techniques to finish the outside diameter but centreless grinding process does not take the inside diameter of the bearing into account, the centres of the outside diameter and inside diameter may not be the same.
GMP bearings are mounted on a mandrel and ground on a cylindrical grinder, thus achieving better concentricity as well as cylindricity to the full length of the bearing so that it is perfectly circular, perfectly straight and has no taper, as compared to bearings turned on a lathe machine.
GMP Composite Cutlass Rubber Bearings offer all the benefits of our brass shelled bearings with added benefit of being lightweight (1/3 the weight of brass bearings) and no galvanic corrosion due to its anti-electrolytic properties.
GMP Composite Cutlass Rubber bearing are made of proprietary composite materials developed by our in house R&D team. The material is resistant to oil, grease and chemicals and match the temperature range of metal bearing materials to function at temperatures from 5°C to 70°C.
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High temperature resistance and negligible swelling characteristics of GMP composite rubber bearings enable them to operate at a closer running clearance than other bearing materials.
The composite outer shell is kept flexible for better grip when pressed into the housing. Our shell material also has bearing properties, so even if the soft lining is worn out the shaft will not be damaged.
GMP Composite Cutlass Rubber Bearings are available in brown and black colours. GMP Flanged Composite Cutlass Rubber Bearings is available only in black.
Our Flanged Bearings designed for heavy duty operations are cast centrifugally at our own facility with an integral flange; the shells are heavy walled to provide structural strength. The flange is bolted to the stern tube or strut housing to retain the bearing and prevent rotation within the housing.
Shells are furnished un-drilled unless specified. GMP flanged Marine Cutlass Rubber Bearings are available in cylindrical circular or split semicircular designs.
Sizes to add
The elastic characteristic of the rubber polymer allows the landing surface to deform and create a natural pocket allowing a hydrodynamic lubricating film to completely separate the bearing surface and the shaft. At this stage the coefficient of friction is well under 0.001, reducing "system wear" to a negligible amount.
A seal is created at the leading and trailing ends and bearing "land" areas causing hydrodynamic grit rejection. Abrasive grit is flushed out through alternating grooves, protecting the shaft from damage.
The tribology forces of rubber, when lubricated with water makes it one the most slippery materials. When sliding on a wet metal surface friction can be virtually eliminated, making it the perfect material to use for water-lubricated bearings.
1. The elastic properties of rubber allows grit and dirt to press into its surface until they are flushed out, protecting the shaft from scoring - unlike hard surface materials that can cause excessive shaft wear.
2. Rubber is able to utilize any lubricants with low viscosity, such as water.
3. When starved of water, rubber will not wipe or fail in a sudden catastrophic manner like hard surface materials. Rubber can crystallize but will always maintain its form.
4. Each rubber landing area acts as an independent bearing surface.
5. Rubber bearings always have contact area due to the elastomeric properties.
6. Water-lubricated rubber has twice the specific heat of oil. An equal weight of water will absorb twice the heat of oil lubricants.
Water lubricated rubber bearings offer an alternative solution to the ever growing concerns of environmental restrictions, the high costs of maintenance and the replacement in today's marine industry. How are rubber-lined bearings an alternative? They use water as the lubricant. This concept is very important because if water is used rather than oil, contamination seals are not required. If seals are not required, pumps and tanks may not be necessary. This leads to a simpler shaft bearing system and immediate cost savings.
1. The proprietary rubber formulation of the lined bearing is broken up by water grooves into a number of lands or faces. These surface lands run parallel to the shaft and serve in supporting it. A tough resilient rubber compound is selected which is relatively immune to the action of grit and sand and also helps reduce noise and vibration.
2. When a grit is trapped between the shaft and the rubber, it is depressed into the landing's elastic surface and rolled into an adjacent water groove where it is immediately flushed out of the bearing.
3. With proper loading, rotational speed and clearances, a water wedge is formed in the rubber landing causing the shaft to ride on a thin film that totally separates the shaft and bearing surface. This is known as hydrodynamic lubrication. At this juncture both friction and wear decrease significantly in a rubber bearing.
4. Our proprietary rubber formulations have nothing more to prove. Rubber bearings are on more vessels around the world than any other material. Our Johnson Cutless Bearings have set unbelievable performance records that other bearing materials are still trying to meet.
General Metals & Polymers is an ISO 9001:2015 certified company, with state of the art manufacturing facility to produce bearings in bulk quantities.
