After prolonged use, gear reducers may experience increased vibration and noise. The main reason for this phenomenon is that the internal components of the chassis are worn out or damaged.

1. First, understand the manufacturing process of the gearbox gear, and then analyze it step by step.

Gear manufacturing process: material preparation → forging blank → normalizing treatment (low-temperature annealing) → rough turning → semi precision turning → gear hobbing → gear end chamfering → high-frequency quenching → precision machining (grinding end face B → grinding end face C → keyway insertion → grinding inner hole → grinding teeth → deburring) → inspection

2. Gear material selection and heat treatment

Gear transmission is usually divided into two categories: hard tooth surface gear transmission and soft tooth surface gear transmission. The choice of gear transmission depends on design requirements. Both types of gear transmission have their own advantages and disadvantages, but due to the high load and long service life of hard tooth surface transmission, it is widely used. There are many materials and heat treatment methods used for hard tooth gears, such as several commonly used ones:

(1) 40Cr. 45 #. 45Mn2 steel can be treated with high-frequency tempering or nitriding;

(2) 20Cr.20CrMnTi, 20CrMnVB.20CrNiH, etc. can be quenched by carburizing;

(3) 38CrMnAl can achieve higher hardness through nitriding process, and some special materials require special heat treatment methods.

Gears with soft tooth surfaces have lower load-bearing capacity, but are relatively easy to manufacture and have good running in performance. They are often used in general machinery with no strict restrictions on transmission size and weight, as well as in small-scale production. Due to the heavier burden on the small wheel in the paired gears, in order to ensure that the working life of the large and small gears is roughly equal, the hardness of the small wheel tooth surface is generally higher than that of the large wheel.

3. Gear wear

Gear wear refers to the process of continuous friction and consumption of gear surface materials during the meshing process. Gear wear can be divided into many types of wear and various degrees of wear. According to the analysis of transmission engineers' years of experience, in addition to tooth breakage and abnormal wear of gears (referred to as abnormal wear here, as normal wear of gears cannot be considered a fault. Abnormal wear refers to premature wear of gears that do not meet the expected wear life of gears), there are also damage forms such as tooth surface pitting and peeling. Tooth surface pitting and peeling often occur in the middle and top of the tooth height.

The metal on the two meshing tooth surfaces of a gear is subjected to adhesive wear due to direct contact under certain pressure, followed by relative motion after welding. The metal is torn off from the tooth surface or transferred from one tooth surface to another, causing damage. The macroscopic characteristic of adhesive wear is that the tooth surface presents rough grooves with varying depths and widths along the sliding speed direction.

Tooth contact fatigue occurs when gears experience both relative rolling and sliding during the meshing process. The action of these two forces generates pulsating cyclic shear stress deep in the surface layer of the gear. Under the repeated action of this shear stress, the gear teeth cause local metal peeling and damage.