A series of problems will occur in the transmission process of gears. There are many kinds of gears. The general structure of gears includes gear tooth surface, normal surface, tooth top circle, tooth groove, end face, tooth root circle, base circle, scale circle, plastic deformation of tooth surface that may occur in gear transmission, gear fracture and assembly error, etc. So what caused this error?
Gear surface plastic deformation occurs during gear operation. When the gear structural material is soft and the transmission working load changes greatly, it is easy to produce plastic deformation of the tooth surface. Under the interaction of excessive friction between tooth surfaces, the contact stress of tooth surface will exceed the yield strength limit of other materials, and the tooth surface material can enter a plastic development state, resulting in the plastic flow of metal on the tooth surface. This causes the driving gear to form a concave groove on the tooth surface near the pitch line, and the driven gear to form a convex ridge on the tooth surface near the pitch line, thus damaging the tooth shape. Sometimes there is no "flash burr" on the driven tooth surface of the gear selected for certain data types. In severe cases, the extruded metal will fill the top gap as metal, which will cause severe vibration, and may even cause time bending or fracture, affecting the normal meshing transmission of the gear system.
Manufacturing error: typical errors in gear machining, such as eccentricity, pitch error, base pitch error and tooth profile error. Gear deformation caused by fixed error, heat treatment internal stress, etc. When the gear error is large, it will cause slight inertia interference of the gear drive, make the gear drive rotate slowly and quickly, and make the gear pair mesh with impact, vibration and noise.
Gear fracture: in gear transmission, the driving force and reaction force of the driven gear interact with each other's gear through the contact point. Even if there is no impact load, under the action of alternating load, fatigue crack is easy to occur when the stress is concentrated, and the fatigue fracture occurs at the root of the tooth. In addition, due to manufacturing and installation errors, quenching cracks, grinding crack damage and too thin tooth thickness after severe wear, fracture may occur at any part of the gear tooth.
Assembly error: due to the assembly information technology and assembly design method, the contact at one end or the straightness deviation of the gear shaft will lead to uneven load bearing capacity of different gears, resulting in the overload of individual gear teeth, causing local early wear, and even not causing gear tooth fracture in serious cases. The unbalance of gears will cause huge impact vibration and noise.
