所谓V±x　齿轮是指齿轮副的齿数和多或少了x个齿,但中心距和标准齿轮相同的齿轮。　　　　由公式　　　　得出由此又得V±x　齿轮是λ恒等于x/2的变位齿轮。由于　V+x　齿轮要采用负变位,齿轮的啮合性能要降低,所以一般不采用。而V-x齿轮要采用正变位,齿轮的啮合性能可以得到 The so-called V ± x gear refers to the number of gear pairs and more or less x teeth, but the center distance and the standard gear of the same gear. From the formula it follows that the V ± x gear is again a variable gear with λ constant equal to x / 2. As V + x gears to be used negative displacement, the gear meshing performance to be reduced, it is generally not used. The V-x gear to be positive displacement, the gear meshing performance can be obtained