工程机械在检修中经常要把套镶入座孔中。套对座孔一般为过盈配合,在常温压入或打入,会使套内孔收缩。为保证套与轴的动配合间隙要求,须适当加大套内孔,其加大量就是套镶入座孔中的收缩量。套在常温镶入座孔后金属晶格变形很小,其密度变化不大,对收缩量影响甚微,可以忽略不计,因此套镶入前后断面积应该相等。如 Construction machinery in the overhaul often need to put sets of inserts into the hole. Set of holes on the seat is generally interference fit, press into or into at room temperature, will make the sleeve shrinkage. In order to ensure the sleeve and the shaft with the gap requirements, to be appropriate to increase the set of holes, the increase is the amount set sleeve set into the hole in the amount of contraction. Set at room temperature set into the seat hole metal lattice deformation is small, the density of little change in the amount of contraction has little effect, can be neglected, so sets of inserts before and after the cross-sectional area should be equal. Such as