Trelleborg Orkot Manual, Catalog, Material Grades & Fitting Information

Products

Material grades

Orkot® Marine Bearings are manufactured from a unique synthetic composite incorporating solid lubricants to ensure outstanding wear life. With virtually no swelling in seawater and a very low thermal coefficient of expansion, the bearings provide dimensional stability in arctic and tropical seas. In addition, they do not corrode or promote corrosion of the housing and shaft and tolerate both edge loading and misalignment.

Orkot® TLMM Marine
This standard material incorporates a woven fabric reinforcement and solid lubricants within a thermosetting resin matrix. It can be used in conjunction with water and grease lubrication, running dry for limited periods.

Orkot® TXMM Marine
A further development of Orkot® TLM Marine, Orkot® TXMM Marine utilizes a specialized bearing surface to extend its dry running capabilities, reducing friction and wear rates. The material can also be used with grease and water lubrication.

Literature

Marine Bearings Engineering Manual

 

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Orkot® TLM and TXM Marine Bearings

 

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Fitting

Orkot® Marine Bearings can be fitted using any one of the following methods. The Orkot® Marine Bearings Engineering Manual provides in-depth guidance on installation.

Bonding

Dependent upon the design employed, in addition to traditional mechanical fixing, Orkot® materials can be bonded to both itself and metallic substrates.
If the assembly is to exceed a temperature of +60 °C to +70 °C/ +140 °F to +158 °F, then interference fit should be replaced with bonding.
Numerous adhesives are compatible with Orkot® and have been tested within our laboratory facilities. Generally the most suitable adhesives are:
  • Epoxies
  • Acrylics
  • Polyurethanes

For specific details of bonding agents and conditions, please see our engineering manual or contact your local Trelleborg Sealing Solutions marketing company.

Press Fit
A hydraulic press or center pull jacks are required if a bearing is to be press fitted. Installers should ensure that they have the equipment available to deliver adequate force to press the bearing fully into the housing.
The ease of fitting will vary dependent on the finish of the housing. This should be considered when calculating the force required.
When press fitting a bearing, it is important that it is in line and square with the bore before the operation beings. An adequate chamfer on the housing will prevent shaving of the bush.


Freeze Fit
Freeze fitting, using liquid nitrogen is a fast and efficient assembly method for an Orkot® Marine bearing. The thermal properties of the material allow a good clearance between the bearing and housing when frozen and the material does not become brittle at cryogenic temperatures.
Freeze fitting using dry ice and alcohol will only provide the required clearance when using very light interferences. As such it is rarely a viable method in its own right and will often require press fitting as well. Additional keeper plates and anti-rotation devices might be required to comply with certain Classification Societies.

Machining

Orkot® materials can readily be machined using conventional machine shop techniques. As a general guide, methods used for brass, aluminium or lignum vitae will apply to Orkot® materials. It is preferable to use tungsten carbide turning tools with cutting speeds of 5 meters/ 20 feet per second. Orkot® materials must be machined dry without the use of coolant.

For specific details of machining, please see the Orkot Engineering Manual or contact your local Trelleborg Sealing Solutions marketing company.


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