New self-lubricating plastic plain bearings used on isolation switch
New self-lubricating plastic plain bearings used on isolation switch
First, the definition of isolation switch
Isolation switch (Disconnector) is mainly used in high voltage electrical installations will require partial blackout and reliably isolate live parts,
To ensure the safety of maintenance work. That is, when the isolation switch location, between the contacts have to meet the requirements of insulation distance and apparent breaking opening
Chi; in the engaged position, the circuit can carry current under normal conditions and abnormal conditions within the specified time (eg short circuit) under the current open
Second, the isolation switch works
Chang Lu isolation switch contacts all in the air, with a clear break point, there is no isolation switch interrupter device, and therefore can not be used to cut off the load current or short circuit current, otherwise, under high pressure, disconnect produce a strong arc point and difficult to extinguish themselves, and may even cause arcing (relative or phase short circuit), burning equipment, endangering personal safety, which is called "negative Hera isolation switch" in a serious accident. Isolating switch can also be used for some of the circuit switching operation to change the system runs. For example: In dual-bus circuit, you can run the circuit switching isolating switch from one bus to another bus. At the same time, it can also be used to operate small current of the circuit;
Third, the disconnector rotating parts sliding bearings are used
Isolation switch contacts is isolated knife switching operation can rely on complete manual and electric control, but whether it is the kind of need all rotating parts can successfully operate in any case, which requires all rotating parts of the bearing in the longer after the pause time can still ensure the normal operation; in order to ensure isolation in the annual inspection process can be normal switch operation, which required the rotating parts of the sliding bearings can resist high and low temperature all year round and staggered when the rear face of the cover can still fail erosion resistance to various external factors, such as failure to salt spray, acid rain, oxidation corrosion caused by natural factors and so on.
Early isolation switch manufacturers at home and abroad in order to solve the various moving parts isolated isolation switch after a long stop still smooth functioning of all moving parts are used in the metal sliding bearings, such as powder metallurgy bearings, bearings and copper alloy layer composite bearing; bearing corrosion rust, etc. these failures have adopted, although the process of self-lubricating metal bearings but can not change the drawbacks, such as a dry lubricant easy consumption, resulting in the closure after the failure phenomenon can not ensure long-term isolation switch stopped working properly . At present, the use of certain proportion of three composite bearings, although the inner diameter of the working surface of the sintered lubricating layer, but this layer a lubricating layer thickness of only 0.03mm, when the lubricant layer on the surface of the rotating shaft off work with the underlying metal layer of copper or low direct contact with carbon steel, which may result in a long pause and the rear axle bearing metal surface rust adhesion occurs, there is a risk of failure isolation switch. In order to solve these risks isolating switch manufacturer in Europe first began to try to use the new plastic bearings and after many years of use of proven engineering plastics self-lubricating bearings to rotate the risk of failure to become the most effective means of self-lubricating solve isolation switch.
Fourth, self-lubricating plastic bearings wear mechanism
CSB-EPB series self-lubricating plastic plain bearings reason has excellent self-lubricating properties and wear resistance are mainly companies to take advantage of the CSB
Self-lubricating material modification technology in high-performance engineering plastics with a high-strength fiber material to improve the bearing grease and special reduced
Friction coefficient of the material, thereby improving the wear resistance of composite materials to extend the service life of plastic bearings.
(For more information please refer to Chinese CSB company "plastics self-lubricating bearings" manual)
Performance engineering plastics as the base material is mainly used as wear-resistant carrier;
Reinforcing fibers increases the bearing carrier and impact resistance;
Special grease reducing the coefficient of friction of the bearing from the self-lubricating;
Fifth, self-lubricating plastic plain bearings for isolating switches Advantage
Self-lubricating plastic bearings CSB-EPB is suitable for rated voltage 40.5KV ~ 252KV indoor and outdoor high-voltage isolation switch all mechanical moving parts, make sure whether it is able to successfully complete "release" and "closing" operation in manual or electric operation .
Use plastic bearing high-voltage isolation switch has the following advantages:
1, since the plastic bearings CSB-EPB can work in a vacuum environment, so use this plastic bearing high-voltage isolation switch is no limit on the height of the installation, it can work at an altitude of 3000 meters above the mountains;
2, plastic bearings CSB-EPB long-term use temperature of -50 ℃ ~ + 110 ℃; so the use of this high-voltage isolation switch plastic bearings used in both hot and cold north or south can work properly; in 10mm thickness above work under the ice.
3, plastic bearings CSB-EPB moisture absorption is very small; the use of this high-voltage isolation switch plastic bearings both in high humidity, rain or high dry summers can complete the normal rotation.
4, since the plastic bearings CSB-EPB uses a fiber-reinforced, so use this plastic bearings can withstand high-voltage isolation switch from high winds (700pa above) or earthquake (8 above) and the various violent vibration.
5, CSB-EPB plastic bearing excellent anti-contamination ability to ensure high-voltage isolation switch work in a variety of bad environments (Pollution Level IV above);
6, plastic bearings CSB-EPB excellent corrosion resistance can be done at a high rotational acid rain or salt spray environment, the successful completion of each part of the traditional metal bearings can not be completed;
7, Plastic bearings CSB-EPB overall material is uniformly distributed a variety of high-lubricating solid lubricant during installation without MoS2 coated with lithium-based grease can complete the normal rotation movement; either manual or electric remote control operations can be done.
8, the use of plastic bearings CSB-EPB high-voltage isolation switch in the whole "closing" or "gate" process isolation knife operation will not occur due to relatively stable rotation of each rotating parts caused by poor isolation knife jitter.
9, CSB-EPB excellent self-lubricating wear resistance and anti-aging properties (over 20 years) to ensure the high-voltage isolation switch can be done than 100,000 mechanical movement.
Self-lubricating plastic plain bearings CSB-EPB series isolation switch is widely used in foreign countries for many years, but the current domestic manufacturers by virtue of the success of the isolation switch overseas experience has gradually started. CSB-EPB series self-lubricating plastic bearings, with its unique advantages are being designed to use all walks of life, especially in the domestic isolation switch design and manufacturing standards to catch up with leading international has created a possibility.