This article tells you the importance of gear box cleanliness in turbine management, the reasons for poor gear box cleanliness, and the measures to improve gear box cleanliness.
Gearbox is the main part in the transmission system, and its normal operation affects the work of the whole system.
In order to improve product quality and prolong service life, an oil filter device is generally installed inside the gearbox to filter the oil, effectively filtering the residual impurities that cannot be cleaned during processing, thereby improving the cleanliness of the gearbox.
1、Importance of gearbox cleanliness
The gear box plays the role of matching the rotational speed and transmitting the torque between the prime mover and the working machine.
Therefore, the normal operation of the gearbox affects the normal operation of the entire system.
Cleanliness refers to the degree of residual mechanical impurities in the system and cavities of the qualified product assembly (including important cavities that are not machined), the holes of the parts and the finished surfaces.
The cleanliness of the gearbox is mainly reflected in the cleanliness of the lubricating oil, iron filings and other impurities generated during the processing and assembly of various parts.
If cleaning is too low, it may directly lead to some of the following failures:
1) After connecting and discharging, the working pressure cannot rise to the specified value.
2) The torque of the gearbox belt row is too large.
3) The oil temperature is too high.
The key to troubleshooting is to improve the cleanliness of the gearbox.
2、Factors causing poor gearbox cleanliness
1.)The purity of the lubricating oil used in the gearbox is poor.
The poor purity of lubricating oil is the direct cause of poor cleanliness:
When the gearbox is running, the lubricating oil enters the lubrication pipeline and is distributed to each lubrication point (mainly the gear meshing area and the bearing area), and the impurities in it also reach the meshing area and the bearing, which affects the meshing of the gear and the life of the bearing.
Therefore, it is recommended to use special oil for gearboxes, so that the purity of the lubricating oil can meet the standard requirements, thereby improving the service life of the product.
2)The iron filings generated during the machining of the parts are not cleaned up.
On the one hand, the workers in the next process did not clean the iron filings of the parts due to carelessness, resulting in defects such as pits or scratches on the surface of the parts, affecting the surface quality of the parts;
On the other hand, the iron filings in certain positions are not easy to clean. After the gearbox works, these iron filings will be brought into the working area through lubricating oil, which will cause damage to the parts.
3)Post-processing of some parts is carried out on the assembled finished product. This is a weak link in finished assembly.
4)The sealant falls into the box.
The sealant is generally applied between the joint surfaces, which can effectively prevent oil leakage;
When too much sealant is applied to the joint surface, the sealant will be squeezed into the box and into the lubricating oil after the box or lid is closed, and it will become an impurity in the lubricating oil.
3、The effect of cleanliness on the gearbox
1) Influence on lubrication and pipeline accessories.
The diameter of the oil hole in the gearbox is generally relatively small. After the oil is circulated, the lubricating oil can easily take out the retained iron filings, thereby blocking the working area of the lubricating valve core.
As a result, the lubricating spool cannot work normally, and the excess lubricating oil cannot be discharged in time, which makes the back pressure of the oil circuit system too high, and the oil pressure gauge jumps.
2) Influence on gears and meshing.
In the process of gear meshing, the lubricating oil brings impurities into the meshing tooth surface, destroying the smoothness of the tooth surface, reducing the mechanical performance of the tooth surface, affecting the transmission stability, making the tooth surface prone to pitting, gluing, wear and other failures, shortening its service life.
3) Impact on bearings.
Under normal lubrication conditions, an oil film will be formed between the surfaces of the parts, and there will be no direct contact, which can reduce the friction and wear inside the bearing, improve the bearing performance and prolong the service life.
When the oil contains impurities, the impurities enter between the rolling elements and the raceway of the bearing, increasing the friction and making the rolling elements rotate poorly, especially under high-speed and heavy loads, the raceways and rolling elements will form pits, resulting in Corrosion or other failure forms will affect the service life.
4、Ways to improve the cleanliness of gearboxes
1）Strictly control the processes before and after cleaning.
Formulate a reasonable cleaning process, and the cleaning process of different products should be explored according to the actual production.
After cleaning, the surrounding environment where the parts are placed should be kept clean and stored in the correct way to prevent dust and other impurities from entering the important surfaces of the parts to affect the fitting size and the assembly performance of the product.
2) Control cleanliness as a quality control point.
After the cleaning operation, select the appropriate method to check the cleanliness of the product surface.
Such as visual inspection: Check the surface for residual oil, grease and other dirt or other foreign matter;
Wipe test: wipe the surface of the product with a clean, lint-free cloth, and observe whether there is foreign matter contamination on the cloth;
Solvent tests, etc.
3) Select the special lubricating oil for the gearbox, and check the cleanliness of the oil regularly.
The gear box is equipped with copper-based friction plates, which are easily corroded by oils with certain additives. There are specific requirements for the selection of lubricating oils:
Mineral oil with no Ep additive, viscosity-temperature characteristics equivalent to SAE30 (SAE40 in tropical regions).
It has the requirements of good lubricity, oxidation resistance, rust resistance, non-emulsification, no damage to sealing materials, low foam and non-toxicity.
Maintain, maintain or replace the oil to make the lubricating oil meet the standard requirements, to ensure that the product has passed the 10,000-hour overhaul period, and the copper-based outer friction plate of the wearing parts has no abnormal wear.
4) When the iron filings generated during the actual operation of the gearbox cannot be cleaned, magnetic iron can be added in appropriate positions and cleaned regularly.
Regularly maintain and maintain the gearbox to ensure the normal operation of the gearbox and the normal operation of the entire system.
Sinooutput—— Your shipbuilding one stop spare parts supplier and consultant.
Sinooutput had serviced more than 398 shipyard oversea, the ship types includes cargo ship, container ship, bulk carrier, fishing boat, oil tanker, LCT, Ro-ro and sand suction ships, tug boat, ice-breaker, militray boats and all kinds of speed yachts.
If you have any questions and inquiries about our products, please add WhatsApp 008613564780885, or leave us a message. We will provide you with professional consulation and catalogs.
