How to judge whether the reducer is mixed with impurities

The determination of whether impurities are mixed in the reducer can be gradually verified through four levels: visual inspection, oil analysis, operation status monitoring, and disassembly inspection. From simple and easy to operate on-site quick judgment to accurate physical and chemical testing and internal component inspection, a complete judgment system is formed from the surface to the core. Different methods are adapted to different scenarios such as daily inspection, suspected pollution investigation, and fault tracing. The practicality and accuracy are improved in sequence. The specific judgment methods and standards are as follows:

1、 Visual inspection: quick on-site initial judgment, suitable for daily inspection and preliminary investigation

By observing the external parts of the gearbox, the appearance of the oil, and the oil discharge/injection ports with the naked eye and simple tools, it is possible to quickly determine whether there is obvious impurity contamination, without the need for professional equipment, and can be completed on site in real time.

Check the appearance of the oil: Open the oil inlet cover plate and oil level gauge of the gearbox, and directly observe the color, transparency, and condition of the internal lubricating oil. Normal lubricating oil should maintain its basic color (new oil is light yellow, transparent white, and light brown after use), no suspended solids, no stratification, and no sedimentation. If the oil appears cloudy, white, black, with particles, obvious mud/metal debris floating, or if there is black sludge and yellow impurities settling at the bottom of the oil tank, it indicates that solid impurities have been mixed in; If the oil is white and accompanied by foam, in addition to water, it will also form emulsified impurities due to the combination of water and impurities, which belongs to the category of impurity pollution.

Check the oil drain port/magnetic oil drain plug: Drain a small amount of old oil into a clean transparent container and observe whether there are visible metal shavings, sand and gravel, and fiber impurities in the oil. If the reducer is equipped with a magnetic oil drain plug, the surface of the oil drain plug should only adsorb a small amount of fine black metal powder (powder from normal wear of gears and bearings can be removed by filtration). If there are obvious metal shavings, iron slag, sheet metal particles, or non-magnetic sand and gravel, plastic particles adsorbed, it indicates that there are a large number of impurities mixed in; At the same time, check the oil drain filter screen (if any). If the filter screen is clogged or has a thick layer of impurities attached to its surface, it is also direct evidence of impurity mixing.

Check the sealing parts and external interfaces: Observe the oil seal, flange sealing surface, oil injection port, oil level hole and other parts of the reducer shaft end. If the sealing parts are damaged or aged, or if the interface cover plate is not tightly sealed, external dust, sediment, and rainwater will enter the interior through the gap. Such sealing failure is likely to be accompanied by impurities mixed in; At the same time, check the surrounding environment of the gearbox. If the equipment is in a dusty, sandy, and humid working condition (such as mining, metallurgy, and construction machinery) without protective measures, the probability of impurities mixing in will increase significantly.