The worm gear reducer is a transmission machine with compact structure, large transmission ratio and self-locking function under certain conditions.Among them, the hollow shaft worm gear reducer not only has the above characteristics, but also has convenient installation and reasonable structure, and has been widely used.It is a helical gear reducer installed at the input end of the worm gear reducer. The formed multi-stage reducer can obtain a very low output speed, which has higher efficiency than a single-stage worm gear reducer, and has less vibration, noise and energy. Low consumption.
XNUMX. Common problems and their causes
1. The reducer heats up and leaks oil.In order to improve efficiency, worm gear reducers generally use non-ferrous metals as worm gears, and worms use harder steel.Due to the sliding friction transmission, more heat will be generated during operation, which will cause differences in thermal expansion between the various parts of the reducer and the seal, thus forming gaps in each mating surface, and the lubricating oil will become thinner due to the increase in temperature, which is easy to cause leakage. .
There are four main reasons for this situation. One is the unreasonable combination of materials; the second is the poor quality of the friction surface; the third is the incorrect choice of lubricant; the fourth is the poor assembly quality and use environment.
2. Worm gear wear.The worm gear is generally made of tin bronze, and the paired worm material is hardened to hrc45 with 4555 steel, or 40cr hardened to hrc5055 and then ground to a roughness of ra0.8μm by a worm grinder.The reducer wears very slowly during normal operation, and some reducers can be used for more than 10 years.If the wear rate is fast, it is necessary to consider whether the selection is correct, whether it is overloaded, and the material of the worm gear, the quality of assembly or the use environment.
3. The drive pinion helical gear is worn.Generally occurs on the reducer installed vertically, mainly related to the amount of lubricating oil added and the type of oil.When installed vertically, it is easy to cause insufficient lubricating oil. When the reducer stops running, the transmission gear oil between the motor and the reducer will be lost, and the gears will not get the proper lubrication protection.When the reducer is started, the gears are not effectively lubricated, causing mechanical wear and even damage.
4. Worm bearing is damaged.When a failure occurs, even if the gearbox is well sealed, it is often found that the gear oil in the reducer is emulsified, and the bearings are rusted, corroded, and damaged.This is because the condensate produced by the gear oil temperature rises and cools down after the gearbox has been running for a period of time is mixed with water.Of course, it is also closely related to the bearing quality and assembly process.
Two, the solution
1. Ensure assembly quality.You can buy or make some special tools. When disassembling and installing the parts of the reducer, try to avoid knocking with other tools such as hammers; when replacing gears, worm gears and worms, try to use original accessories and replace them in pairs; when assembling the output shaft, pay attention to Tolerance fit; use anti-sticking agent or red dan oil to protect the hollow shaft to prevent wear and rust or scale on the mating area, which is difficult to disassemble during maintenance.
2. Selection of lubricants and additives.Worm gear reducers generally use 220# gear oil. For reducers with heavy loads, frequent starts, and poor use environments, some lubricating oil additives can be used to make the gear oil still adhere to the gear surface when the reducer stops running, forming protection. Membrane to prevent direct metal-to-metal contact during heavy loads, low speeds, high torque and start-up.The additive contains seal ring adjuster and anti-leakage agent, which keeps the seal ring soft and elastic and effectively reduces the leakage of lubricating oil.
3. Selection of the installation location of the reducer.Where the location permits, try not to use vertical installation.In vertical installation, the amount of lubricant added is much more than that in horizontal installation, which may easily cause heat generation and oil leakage of the reducer.
4. Establish a lubrication maintenance system.The reducer can be maintained according to the "five-determination" principle of lubrication work, so that each reducer has a responsible person to check regularly, and it is found that the temperature rise is obvious. When more copper powder and abnormal noise are found in the machine, stop using it immediately, repair it in time, remove the fault, and replace the lubricating oil.When refueling, pay attention to the amount of oil to ensure that the reducer is properly lubricated.