磨机大齿圈加工工艺及精度的综合分析

Comprehensive analysis on machining process and precision of gear ring of mill

随着磨机的大型化、高要求,磨机大齿圈直径已达13 m,齿幅宽度0.8~1 m,结构有两瓣或4瓣,硬度340~380HB,模数32~40,精度AGMA10级,齿面粗糙度Ra3.2,这给大齿圈加工带来极大困难,解决大齿圈加工精度问题成为关键。通过对大齿圈结构、材质和热处理要求进行分析,采用合理的工艺流程,选用合适的机床,通过机夹硬质合金滚刀滚切加工试验、分析对比,优化切削参数,顺利完成了大齿圈的加工。测量结果显示,齿轮齿形、齿向、周节、周累精度达到要求,齿面粗糙度达到Ra1.0,对滚啮合试验和装配试车啮合检测结果显示,齿高、齿长接触面积完全达到图纸要求。最后一刀精滚时间仅16 h 40 min,提高了效率,降低了成本。

As the mill is getting larger and larger as well as the requirements for it higher and higher, the maximum gear ring of the mill is characterized by diameter of 13 m, tooth width of 0.8 ~ 1 m, two or four segments, hardness of 340 ~ 380HB, module of 32 ~ 34, grade of AGMA10 and tooth surface roughness of Ra3.2, which brings great difficulty in machining of the gear ring, thus to achieve the required machining precision of the gear ring becomes the key issue. After the requirements about structure, material and heat treatment being analyzed, reasonable machining process and suitable machine tools were applied, as well as hobbing test with clamping hard alloy hob was conducted and compared. The hobbing parameters were optimized, and the machining of the gear ring was achieved. Measurements showed that the profile,lead, pitch and accumulated pitch precision of the tooth met the requirements, as well as the tooth surface roughness reached to Ra1.0. Gear engagement test and assembly run-test showed that the contact area in tooth height and length totally met the drawing requirements. The final hobbing only lasted for 16 h 40 min,thus the efficiency increased and the cost decreased.