TH6213Boring And Milling Machine Spindle Components Optimized Design

More and more parts in ships, aircrafts and other heavy equipments require precisionmachining, and the precision demand is higher and higher, which bring higherrequirements for machine tool. In the domestic, for this kind of large CNC boring andmilling machine in some parameters such as precision and speed, there is still a certain gapwith the international advanced level. At present, most researchers focus on the ordinaryspindle of large machine tool. This thesis studies on the structure and properties of thedual-spindle which can move along the axial direction.Structure of the spindle was determined, and the appropriate support was selected.Analysed the relationship between the spindle nose deformation and the boring spindleextending length. Considering the bearing stiffness, the bearing axial position and thelength of each spindle segment were optimized, and got a relatively suitable bearingconfiguration for the whole working process. Make it zero error when the boring spindleextends half the distance for compensation, that means the maximum error will be cut tohalf, the machining precision was improved. After the main structure of the spindle wasdetermined, the modal analysis and the harmonic response analysis was carried out tomake sure that the main response will not occur in the design working conditions, and atthe same time, provides a reference for improving the performance of the machine tool ordesigning similar machines. For the large amplitude place, some solutions can be broughtin such as increasing the damping.In the special spindle experiment platform, the oil-air lubrication test was carried out,and the optimized parameters were determined. According to the bearing workingconditions, estimated the bearing heat generation, spindle cooling. So the temperaturedistribution in the thermal equilibrium state of the spindle was got, and targeted for cooling.The temperature distribution of the spindle is related to load and boring spindle extendinglength. In order to obtain better cooling effect and small temperature difference, make a subsection cooling, give an appropriate amount of cooling oil according to the temperatureof this section. Conventional spindle cooling method has been tested in the spindleexperiment platform, it was found that the temperature field will vary with the processingconditions. Because of the constant cooling oil providing, the spindle cannot get wellcooled when spindle speed increased. Can be inferred that controllable section cooling isnecessary and effective.In this paper, a dual-spindle structure of CNC boring and milling machine wasdeveloped, the support was optimized and a high precision spindle structure was got. Thethermal effect was analyzed and tested, reasonable bearing lubrication and spindle coolingwas determined.