D51-250型扩孔机(见封面)是一机部铸锻机械研究所设计,由济南生建机械厂于1966年5月试制成功的新产品。它主要用于滚动轴承厂作环形毛坯热扩孔用。其主要特点是:结构简单、辗压力大、刚性好、生产率高,并有手操纵或脚操纵方式可供操作人员任意选择。本机是属开式的扩孔机,床身系采用铸钢整体结构,由铸铁的支架将其与底座和减速机联为一体。因此刚性较好。其传动采用三角皮代——一级圆柱斜齿轮通过万向轴节使滑块上之 D51-250 type reaming machine (see the cover) is a mechanical casting forging machine design Institute, built by the Jinan Health Machinery Factory in May 1966 successful trial of new products. It is mainly used for rolling bearing plant ring blank reaming with. Its main features are: simple structure, rolling force, rigidity, high productivity, and hand manipulation or foot manipulation for operators to choose. The machine is an open reaming machine, the whole body structure of the cast steel, cast iron bracket with the base and reducer linked to one. So the rigidity is better. The transmission uses the Triangle skin generation - a cylindrical helical gear through the universal joint so that the slider