How to improve the breaking resistance of gears
The methods to improve the gear breaking resistance are as follows: 1. increasing the modulus of the gear. 2. take positive displacement. 3. use materials with higher mechanical properties. 4. increase the center distance. Etc..
In order to improve the anti fracture ability of gear, can take the following measures: 1) with the method of increasing the root fillet radius and eliminate the machining marks to reduce tooth root stress concentration; 2) increase the rigidity of the shaft and bearing, so that the tooth contact line under load is more uniform; 3) by heat treatment method suitable to tooth core the material has enough strength and toughness; 4) by shot peening or cold rolling process on root surface strengthening treatment.
In helical gear drive, the contact line on the working surface of the gear teeth is a diagonal line (see legend). If the load is concentrated after the teeth are loaded, local fracture will occur. If the manufacturing or installation is bad or the bending deformation of the shaft is too large, the part of the gear is loaded too much, even the spur gear will break partially.
tooth breakageThere are many forms of tooth fracture, under normal circumstances, mainly because of the broken tooth root bending fatigue, tooth load, tooth root bending stress produced by the largest section, plus part of the tooth root transition mutation and cutting marks caused by stress concentration, when the tooth re loaded, fatigue crack the root will be produced, and gradually expanded, resulting in fatigue fracture of teeth. In addition, when the gear tooth is subjected to sudden overload, it may also be overloaded, broken or sheared. When the teeth are badly worn, the thickness of the tooth will be broken when the tooth thickness is too thin.
