轴上的键槽中心要求对称于轴的中心线,这样构键槽称为对称中心键槽。对于成批生产的零件,可以做专用夹具,用“对刀块”或“对刀样件”等对好刀后定位加工。这是比较容易做到的。对于单件或小批生产,不可能一种零件做一个专用夹具来加工。因此通常的方法是采 The keyway axis on the shaft requires symmetry to the centerline of the shaft so that the keyway is called a symmetrical center keyway. For mass production of parts, you can do a dedicated fixture, with the “knife block” or “on the knife-like pieces,” such as after a good knife positioning processing. This is easier to do. For single-piece or small-batch production, it is not possible for a part to be machined as a special fixture. So the usual method is to adopt