During the operation of the speed reducer, the friction and heat of the pair of movements and the influence of the ambient temperature increase the temperature of the speed reducer. If there is no air hole or air hole blocking, the pressure in the machine gradually increases. The higher the temperature inside the machine, the more The greater the pressure difference, the lubricating oil leaks out of the gap under the effect of differential pressure; then how to handle the failure detection of the reducer such as wear and leakage?熹垚 Xiao Bian gives you a few suggestions. Useful people will collect them!
The structural design of the reducer is irrational: the inspection hole cover plate is too thin, and it is easy to deform after tightening the bolt, so that the joint surface is uneven, and oil leaks from the contact gap;
During the manufacturing process of the speed reducer, the casting is not annealed or aged, and internal stress is not eliminated, deformation will occur, gaps will occur, and leakage will occur.
There is no oil return tank on the tank, lubricant oil accumulated in the shaft seal, end cover, joint surface, etc., under the effect of pressure difference, leak out from the gap;
Shaft seal structure design is irrational: early use of reducer oil groove, felt ring type shaft seal structure, the assembly will be compressed by the deformation of the felt, and the joint surface gap sealed. If the journal is not perfectly in contact with the seal, the seal will fail in a short time due to the very poor compensation performance of the felt. Although there are oil return holes in the oil trench, it is easy to block and the oil return effect is difficult to play.
Too much refueling: During the operation of the reducer, the oil pool is stirred very violently, and the lubricating oil splashes everywhere in the machine. If the refueling amount is too much, a large amount of lubricating oil accumulates in the shaft seal, joint surface, etc., resulting in leakage. .
Inappropriate overhaul process: When the equipment is overhauled, oil leakage may occur due to incomplete removal of dirt on the bonding surface, improper use of sealant, reversed seal orientation, and failure to replace seals in time.
The poor operating environment of the reducer often causes wear, leakage and other failures. The most important are:
1. The bearing room of the reducer wears, which includes the wear of the housing bearing box, the bearing hole in the box body, and the gearbox bearing room;
2, reducer gear shaft shaft wear, the main wear parts in the shaft head, keyway, etc.;
3, reducer drive shaft bearing position wear;
4, reducer leakage surface.
For the wear problem, the traditional solution is repair welding or after brush plating machining repair, but both have certain drawbacks. The thermal stress caused by high temperature welding cannot be completely eliminated, which may cause damage to the material and lead to bending or fracture of components. Brush plating is limited by the thickness of the coating and is easily peeled off; and both methods are used to repair metal with metal and cannot be changed.” "Hard-to-hard" cooperation will still cause wear again under the combined effects of various forces. For some large bearing companies, it is impossible to solve them on the spot, and it is necessary to rely on the repair of foreign companies.
Contemporary Western countries have used the method of repairing polymer composite materials to solve the above problems, and they have superb adhesion, excellent compressive strength and other comprehensive properties. The application of polymer materials can be repaired, free from disassembly and machining, and has no effect on the thermal stress of repair welding. The repair thickness is also not limited. At the same time, the metal materials possessed by the product do not possess the concessional properties, and can absorb the impact shock of the equipment and avoid re-wear. It is possible to greatly extend the service life of equipment components, save a lot of downtime for enterprises, and create huge economic value.
For the leakage problem, the conventional method requires dismantling and opening the speed reducer, replacing the sealing gasket or applying the sealant, which not only takes time and effort, but also makes it difficult to ensure the sealing effect, and leakage will occur again during operation. The polymer material can be used for on-site treatment of leakage. The material has superior adhesion, oil resistance, and 350% stretch to overcome the impact of the reducer vibration and solves the problem of reducer leakage. And formulate a series of countermeasures for oil leakage of reducers:
1, improve the air cap and inspection hole cover:
The internal pressure of the reducer is greater than the external atmospheric pressure, which is one of the main causes of oil leakage. If the pressure inside or outside the machine is balanced, the oil leakage can be prevented. Although the reducer has a breathable cap, but the vent hole is too small, easy to be blocked by coal powder, oil, and each time the refueling should open the inspection hole cover, open once to increase the possibility of an oil spill, so that the original does not leak There is also a leak in the area. For this purpose, an oil cup type air-permeable cap is to be made, and the original thin inspection hole cover is changed to 6 mm thick. The oil cup type air-permeable cap is welded to the cover plate, and the vent hole diameter is 6 mm, which is convenient for ventilation. Pressure equalization, and refuel from the oil cup when refueling, do not open the inspection hole cover, reducing the opportunity for oil spills.
2, smooth flow:
To make the excess oil that is thrown on the bearing by the gears not accumulate at the shaft seal, excess lubricant must be allowed to flow back to the oil pool in a certain direction. The specific method is to open a return oil tank inclined to the machine in the center of the lower bearing of the bearing seat, and at the same time, a notch is opened at the straight end of the end cover, and the notch is facing the oil return tank, so that the excess lubricating oil flows through the notch and the return tank. Return to the oil pool.
3, improve the shaft seal structure:
1) Improvement of the shaft seal of the reducer whose output shaft is a half shaft: The output shaft of the reducer of most equipment such as belt conveyors, screw unloading machines, and impeller coal feeders is a half shaft, and the transformation is more convenient. Disassemble the reducer, remove the coupling, take out the shaft cover of the reducer, and in accordance with the size of the oil seal of the frame, install the skeleton oil seal on the outer side of the original end cover, with the spring side inward. When reloading, if the end cap is more than 35mm from the inner end face of the coupling, a spare oil seal can be installed on the shaft on the outside of the end cap. Once the oil seal fails, the damaged oil seal can be taken out and the spare oil seal can be pushed into the end cap. To understand the time-consuming and laborious processes such as the body speed reducer and the disconnect coupling.
2) Improvement of the shaft seal of the reducer whose output shaft is an entire shaft: There is no shaft coupling for the output shaft of the reducer of the whole shaft transmission. In order to reduce the workload and simplify the installation procedure, a split end cap is designed and the opening is opened. Oil seals were tried. The separable end cover is equipped with an outer side machining slot. When the oil seal is installed, the spring is first taken out, the oil seal is sawn and cut into an open shape, the oil seal is put on the shaft from the opening, and the opening is butted with an adhesive, and the opening is upward, and then loaded. On the spring, push in the end cap.
4, using a new type of sealing material:
Leakage of the static seal of the reducer can be blocked by a new type of polymer repair material. If the oil leaks at the static sealing point during operation of the reducer, the oil surface emergency repair agent of the surface engineering technology can be used to block the sticky-polymer 25551 and 90T composite repair materials so as to eliminate the oil leakage.
5, carefully implement the repair process:
When overhauling the reducer, it is necessary to earnestly implement the procedure, the oil seal must not be reversed, the lip must not be damaged, the outer edge must not be deformed, the spring must not fall off, the joint surface must be cleaned, the sealant must be applied evenly, and the fuel level must not exceed the scale of the oil scale.
6, wipe:
Reducer static sealing point through the treatment, generally can be achieved without leakage, but the dynamic sealing point because of seal aging, poor quality, improper assembly, shaft surface roughness and other reasons, making the individual dynamic sealing point is still a small leak Due to the poor working environment, the coal dust sticks to the shaft and it looks like oil. Therefore, it is necessary to wipe the oil on the shaft after the equipment is stopped.