The helical gear- worm gear reducer is a transmission machine with compact structure, large transmission ratio and self-locking function under certain conditions. Moreover, the installation is convenient, the structure is reasonable, and the application is more and more widely used. It is equipped with a helical gear reducer at the input end of the worm gear reducer. The multi-stage reducer can achieve very low output speed, higher efficiency than single-stage worm gear reducer, and low vibration, noise and energy. low.

First, common problems and their causes

1. The reducer generates heat and oil leakage. In order to improve efficiency, worm gear reducers generally use non-ferrous metals for worm gears, while worms use harder steel. Because it is a sliding friction transmission, more heat is generated during operation, which causes a difference in thermal expansion between the various parts of the reducer and the seal, thereby forming a gap in each mating surface, and the lubricating oil is thinned due to an increase in temperature, which is liable to cause leakage. . There are four main reasons for this situation. One is that the material is not properly matched; the other is the poor quality of the surface of the friction surface; the third is that the amount of lubricant added is not correct; the fourth is the poor quality of assembly and use.

2. Worm gear wear. The worm gear is generally made of tin bronze, and the paired worm material is hardened to 45°C to HRC4555, 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 speed is faster, it is necessary to consider whether the selection is correct, whether it is overloaded, and the material, assembly quality or use environment of the worm gear.

3. Drive small helical gear wear. It usually occurs on a vertical mounted reducer, mainly related to the amount of lubricant added and the type of oil. When the vertical installation is installed, it is easy to cause insufficient lubricant. When the reducer stops running, the transmission gear oil between the motor and the reducer is lost, and the gears are not protected by the lubrication. When the reducer is started, the gears are mechanically worn or even damaged due to the lack of effective lubrication.

4. The worm bearing is damaged. In the event of a fault, even if the gearbox is well sealed, it is often found that the gear oil in the reducer is emulsified and the bearing is rusted, corroded and damaged. This is because the condensed water produced by the gear oil temperature rises and cools after mixing for a period of time. Of course, it is also closely related to bearing quality and assembly process.

Second, the compact helical gear worm gear reducer common causes and problems analysis and solution

1. Guarantee the quality of assembly. You can purchase or make some special tools. When disassembling and installing the parts of the reducer, try to avoid hitting with other tools such as hammers. When replacing gears and worm gears, try to use original parts and replace them in pairs. When assembling the output shaft, pay attention to it. Tolerance fit; use a release agent or red dan oil to protect the hollow shaft to prevent wear and rust or to match the area scale, which is difficult to disassemble during maintenance.

2. Selection of lubricants and additives. The worm gear reducer generally uses 220# gear oil. For heavy-duty trucks with heavy load, frequent start and poor use environment, 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 heavy load, low speed, high torque and direct contact between metals at start-up. The additive contains a seal regulator and a leak preventer to keep the seal soft and elastic, effectively reducing oil leakage.

3. Selection of the installation position of the reducer. When possible, do not use a vertical installation. When installing vertically, the amount of lubricating oil added is much more than that of horizontal installation, which may cause heat generation and oil leakage of the reducer.

4. Establish a lubrication maintenance system. The reducer can be maintained according to the “five-set” principle of lubrication work. Every reducer has a responsible person to check regularly and find that the temperature rise is obvious. If the temperature exceeds 40°C or the oil temperature exceeds 80°C, the quality of the oil will drop or oil. When more copper powder is found and abnormal noise is generated, stop using it immediately, repair it in time, troubleshoot it, and replace the oil. When refueling, pay attention to the amount of oil to ensure that the gear unit is properly lubricated.