Analysis Of Thermal Characteristic & Optimization Design On Direct-drive Lathe

Direct-drive lathe with built-in motor spindle components completely abolished all the intermediate links which between the working parts to the motor. The spindle is droved directly by the motor turning motion, so that the transmission length of the lath is reduced to zero. Thus achieve a lathe "zero transmission". Direct-drive lathe not only totally reduces the effect of the geometry error on the machining precision, but also avoids the effect of the thermal error from the gear transmission structure on the machining precision. However, the effect of the heat on the machining precision, which is from electromotor, bearing and so on, can't be eliminated on the direct-drive lathe.Based on the study on the structure of spindle direct-drive CNC lathe CMK0220, this paper analyzes the heat source, the way of thermal transfer and so on, focusing on the points of simulation analysis and experimental research on total thermal deformation of the machine tool caused by built-in motor spindle. Moreover, optimization design of machine tool thermal properties is carried out. The study can also provide the foundations for other related researches on thermal properties of direct-drive lathes.Firstly, the basic theories of machine tool thermal analysis are introduced in the paper, including the three ways of heat transfer and the cause of thermal strain. This paper lists the thermo elastic equation of thermal stress and its solution, and the calculation of temperature field and coupled field finite element theory are outlined.Secondly, the paper establishes the heat flow model of whole machine tool and analyzes thermal properties of direct-drive lathe on the basis of researches on the structure of lathe and motorized spindle. Thermal characteristics of direct-drive lathe include heat source, heat sink, and the way of thermal transfer, calculation of thermal transfer and calculation of heat. Analysis of heat source and heat sink is basis for thermal analysis basis on machine tool.Thermal characteristics and experimental research based on direct-drive lathe are studied on primarily in the paper. According to the analysis and calculation of machine tool thermal properties, using the software on the direct-drive lathe machine to get a simulated temperature field. After experimental verification of the preliminary result of temperature model was carried out, the deformation model of whole machine tool can be calculated by the heat-structure coupling.Last, based on this analysis, select appropriate methods which optimize the obliquity of machine tool spindle. Optimization results show that the approaches which add to heat rib and additional heat source can effectively improve spindle obliquity of direct-drive lathe.