Spur gears are one of the most common gears in actual production and use. Damage is inevitable during use, so it is necessary to make a new gear that is the same as the original one. Due to various reasons, the customer cannot provide the required spur gear. For the drawings of gears, in order to ensure that the processed products can be used normally, it is necessary to carry out accurate surveying and mapping of gears. The surveying and mapping work is a complicated task. Since there are few materials introducing the surveying and mapping of spur gears, it is naturally inconvenient to consult. Through actual The work experience and methods of spur gear surveying and mapping in several practical productions are summarized. The introduction is as follows:
First of all, although there are many parameters and dimensions of spur gears, the standard system of various gears stipulates that the module or diameter pitch is used as the calculation basis for other parameters and the dimensions of each part. Therefore, in surveying and mapping work, we must try our best to accurately determine the size of the modulus or diameter pitch. At the same time, the pressure angle is the basic parameter for determining the tooth shape, and accurate determination is equally important.
Secondly, we need to understand the usage and production country of the gear being surveyed and mapped, so that we can estimate the standard system adopted by this gear. Generally, my country, Japan, Germany, France, the Czech Republic, and the former Soviet Union are all modular systems, and the tooth profile of the gear can also be observed. If the tooth profile is curved and the bottom of the tooth groove is narrow and arc-shaped, it can be preliminarily judged as a modular system. The standard pressure angle is mostly 20 degrees; the United States and the United Kingdom adopt radial control, and the standard pressure angle is 14.5 degrees and 20 degrees. It is observed that the tooth profile is relatively straight and the bottom of the alveolar is wider and the arc is smaller. It can be initially judged as radial control. The pressure angle is 14.5 degrees, and the gear hob or the standard rack sample can also be used to compare the pressure angle to determine the pressure angle. Knowing the above conditions, you can carry out actual surveying and mapping.
