The performance of POM Composite bearings depends on the interaction of load, lubrication, surface roughness, sliding velocity, and temperature encountered in specific applications.
POM Composite – plain cylindrical bushings:3 layers : a steel or bronze strip to improve mechanical resistance – a porous sintered bronze layer for heat conductivity, dimensional stability and the bonding of the sliding layer – a PTFE based sliding layer with good auto lubricant quality (low wear and low friction).
- Specific load capacity static≤ 250 [N/mm2]
- Specific load capacity dynamic≤ 140 [N/mm2]
- Sliding speed≤ 2.5 [m/s]
- Friction value0.04 [µ] to 0.12 [µ]
- Temperature strain– 40 [°C] to + 130 [°C]
- Max. PV-value2.8 [N/mm² x m/s]
- Support materialSteel copper-plated or tin-plated
- Intermediate layerSintered bronze
- Sliding layerPOM (MoS2)/lubrication pockets
POM composite plain bearings are suitable for applications that require minimal maintenance under difficult operating conditions. As a result of the lubricant retention pockets on the sliding surface,viiplus POM composite plain bearings are especially well-suited for applications in contaminated environments where lubricant cannot be supplied continuously or frequently.
The performance of POM composite plain bearings depends on the interaction of load, lubrication, surface roughness, sliding velocity, and temperature encountered in specific applications.
POM composite bushings lubrication
POM composite plain bearings are designed to operate under marginal lubrication conditions. The sliding surface of these plain bearings contains grease reservoirs which should be filled prior to installation. It is not necessary to relubricate these plain bearings, but the presence of a lubricant can extend the plain bearing service life considerably. To protect the mating surface against corrosion, grease can be applied periodically.
Shaft tolerance h7 – h8
Housing tolerance H7
Shaft roughness Ra, µm 0 .. 0,8
Shaft hardness, HB 150 – 600
Like PTFE composite bearings, POM composite bearings also have a sheet steel backing that
is covered with a 0,2 to 0,4 mm thick layer of sintered tin/bronze . The principal
characteristic of these bearings is their relatively thick (0,3 mm) layer of acetal resin (POM
– polyoxymethylene) that is firmly attached to the sintered tin/bronze layer. The covering
layer has pockets to retain grease. The thickness of the covering layer makes these bearings less sensitive to misaligment and the edge loading associated with that misalignment.
Machining the bore of POM composite bushings
Bushings made of POM composite material are ready for installation. However, if necessary, the bushing bore can be machined to size while mounted in its housing. After machining the bore, the sliding surface should have an Ra value of max 2,5 μm. The following machining recommendations will provide good results when a poly-crystalline diamond cutting tool is used
• cutting speed > 150 m/min
• slow feed rate (0,05 to 0,1 mm/revolution)
• cutting depth 0,1 mm.
To prevent excessive heat build-up of the acetal resin, and to remove the swarf produced during machining, a constant supply of compressed air (at a low pressure) should be applied to the bushing during any machining operation.
plain cylindrical bushings suitable for heavy-duty, low-speed rotary motion, rocking motion, and frequent fluid-lubricated parts that are opened and closed under load. Long-term use without boundary lubrication can be achieved without refueling, while refuelling can be used during the process. The service life is more prolonged; the plastic layer on the surface can leave a certain margin when the shaft sleeve is formed and can be processed by pressing it into the opening to achieve a better assembly size.
The significance of Applying pom material to rubber machinery
For a long time, rubber mechanical roller (or rotor) oil leakage, has not been a good solution.Equipment oil leakage not only pollute the environment, waste oil, more importantly, affect the quality of products.After the oil leakage is cured in the semi-finished products, it will make the products bubble and other foreign products or unqualified products;Or the products can not repair and result in waste products.In particular, calender, bear rubber products bone frame material a adhesive production, the requirements are higher.In the past we contact bearing materials, can not reach neither oil leakage and high temperature conditions of service.Copper tile needs good lubrication, oil leakage is not easy to solve;Although MC nylon can achieve oil-free lubrication, but can not withstand high temperature.So far the rubber calender is still pumping with copper lining, still have to spend a lot of human and material resources to plug the leak, in order to reduce product losses.When we come into contact with the steel back composite (pom material) For its superior benign can attract.
pom materials are all suitable for rubber machinery bearing bush, use it can achieve less oil lubrication, eliminate oil leakage;Compared with nylon material, bearing has better dimensional stability and accurate assembly dimension.To ensure the meshing size of the gear, used for mixing machine, because the bearing bush clearance is small, but also can reduce the wear on the sealing ring, strengthen the sealing performance;Cheaper than copper tile material, convenient assembly, should not burn tiles;Therefore, the application should be vigorously promoted.
- Long service intervals
- Low friction coefficient
- Wide range of use
- Long lifetime
Type of application
- Hydraulic cranes
- Hydraulic cylinders
- Agriculture machines
- Hoisting equipment
- Cylindrical bearings
- Flanged bearings
- Thrust washers
- Drawing details
Technical information and standard dimensions on the data sheet