Gear is transfer movement and power of machinery, has a long history, gear transmission and has a large range of speed ratio and large power, high reliability, accurate transmission ratio, the advantages of long service life, is an essential part of most mechanical equipment transmission parts.
Everyday gear box according to the structural form can be divided into seven categories: involute cylindrical gear box, cycloidal needle wheel fixed axis gear box, arc cylindrical gear transmission gear box, bevel gear drive and hypoid gear transmission, worm drive.Involute planetary gear transmission, the non-circular gear transmission, etc.Different forms of gear structure in transmission ratio, transmission.Work speed, lubrication requirements, reliability, cost efficiency, etc have different advantages and disadvantages, so want to choose suitable for real gear box the desires of their products, to seriously consider the requirements of the following several aspects:
1. Gear case of machine work on the structure and the requirement of dynamic parameters, such as actuator size, quality, power, speed, efficiency and transmission ratio, load characteristic, etc.
2. The performance of the gear case of machine work for requirements: such as reliability, service life, noise, vibration, temperature rise and transmission precision, etc.
3. Gear box, technology advanced, reasonable, economical, general interchangeability.
4. The gear products of low cost, high efficiency, high precision, high reliability and other factors.
Many factors influence of gear damage, such as material selection, processing technology, so that to install such errors could lead to the failure of the gear.In gear work injury is divided into five categories: the basic form of tooth surface wear, fatigue, glue, plastic deformation and broken gear, etc.
Gear wear refers to the gears in the gearbox in the process of meshing gear surface material constant process of friction and consumption.According to the damage mechanism of the wear can be divided into the adhesive wear, abrasive wear and surface fatigue wear, corrosion, wear, etc.And by the depth of the gear abrasion wear can be divided into mild, moderate wear, excessive wear.Two meshing gear tooth surface metal, agglutination abrasion is direct contact with the under certain pressure, and relative motion after welded, the metal from the tooth surface tear falls, or from one tooth to another tooth surface transfer phenomenon and cause of damage.Gear meshing is actually a relatively rolling, and the relative sliding process.The function of these two kinds of force pulse cycle change gear surface layer depths of shear stress.Tooth surface under the action of the shear stress, cause local damage metal flake.The damage forms and pitting fatigue spalling, shallow fatigue spalling fatigue spalling and hardening layer 3 kinds.