Gear transmission is to use two gear teeth meshing transmission power and movement of the mechanical transmission. According to the relative position of the gear axis parallel to the axis of cylindrical gear transmission, intersecting shaft cone gear drive and the staggered shaft helical gear transmission. With compact structure, high efficiency, long service life, etc. （ 1) According to the relative position of two axis and the direction of the tooth, can be divided into the following types: & lt; 1> Cylindrical gear transmission; < 2> Bevel gear drive; < 3> Staggered shaft helical gear transmission. （ 2) According to the working conditions of the gear, can be divided into: & lt; 1> Open gear drive type gear, gear exposed, can guarantee good lubrication. < 2> Half open gear transmission, gear oil pool, a shield, but not closed. < 3> Closed gear, gear, shaft and bearing has been packed in the case closed, good lubrication condition, the dust is not easy to enter, accurate installation, gear drive have good working conditions, is zui widely used gear transmission. And what of the gear precision level? 1, the gear precision mainly control between gear when running gear transmission accuracy, such as: transmission stability, transient speed fluctuation, if has alternating reverse running, whether the tooth clearance small zui, if there is impact load, should improve the accuracy, little to reduce impact load to the destruction of the gear. More than 2, if the design requirement is higher, the gear precision will also be a little higher, on the other hand can be at the bottom of a little 3, however, accuracy of gear set too high, processing cost will rise and the need to overall balance 8, ( Tooth thickness) Deviation level is also the designer comprehensive specific conditions given level, fine mi transmission to a little higher, general machinery to lower, closed transmission to a little higher, exposed drive to lower. 9, ( Tooth thickness) Deviation grade C, D, E, F, G, H, J, K, L, M, N, P, R, S, C level gap zui, zui s-class gap is small. 10, whether it's precision grade and level of deviation, the higher you set, the processing cost is higher, also need to comprehensive analysis and then give a proper accuracy of specific level and deviation of level. 5, for the formula of gear accuracy is no, because do not need to calculate, is to check the manual. Will rank higher precision in this article by the cog belt wheel v-belt pulley original, reproduced please indicate the copyright: http://www. lilainuo。 com