The determination of main parameters of numerical control lathe spindle design
The determination of main parameters of numerical control lathe spindle design release date: 2016 - 07 - 27 clicks: 3141 main parameters of numerical control lathe spindle is to point to: spindle average diameter D ( The spindle front axle neck diameter D1) ; Spindle diameter of bore d. Type a spindle overhanging and spindle bearing span l. These parameters directly affect the work of the spindle performance, but to simplify the problem, mainly by the static stiffness conditions to determine these parameters, namely, choose D, D, a, l make main shaft for maximum static stiffness, both other requirements, such as recommend suite, vibration resistance, etc. ( 1) The determination of CNC lathe spindle front axle neck diameter of 1 d numerical control lathe spindle had a greater influence on the average diameter of spindle assembly stiffness. Increasing diameter D1, can reduce the spindle itself bending deformation caused by the displacement of the spindle shaft end and bearing of shaft end caused by deformation of elastic displacement, so as to improve the spindle component stiffness. But increasing diameter is limited by bearing the dn value, at the same time increasing matching parts size, manufacturing difficulty, structure size and weight increase, etc. , therefore should take smaller values under satisfies the requirement of stiffness. By data according to the principle of lathe main motor power to determine, desirable D1 = 90 mm. ( 2) The determination of CNC lathe spindle hole diameter d CNC lathe to determine the principle of the aperture is, to reduce the spindle weight, in meet the requirement of hollow spindle hole neck and minimum wall thickness requirements and not weaken the request of the spindle rigidity, should take larger value. For nc machine tools, d1D = 0. 6 - 0. 5, this topic of lathe spindle end need to install belt pulley, diameter of axle is lesser, so take d1D = 0. 55 the dd, that is, d = 54 mm. ( 3) Type a CNC lathe spindle overhanging the determination of CNC lathe spindle overhanging a refers to the amount of spindle end to bearing radial reaction before middle distance, its impact on the stiffness of the spindle assembly and vibration resistance is very large. So as far as possible under the premise of meeting the structure requirement of little value. Reduce a common measures are: (1) try to use short cone flange spindle end structure. (2) configuration in the former bearing, thrust bearing shall be installed in the radial bearing inside instead of outside. (3) the reasonable design before the adjustment of the bearing structure and form of sealing device. As far as possible with the spindle end flange and shaft shoulder a sealing device, etc. (4) the centripetal thrust bearing is used to replace the centripetal bearing. Installed in pairs of tapered roller bearings, the rolling cone should be taken in the form of relatively small end; Installed in pairs of centripetal thrust bearing should be taken back to back or facing out the same arrangement. This topic in the end of a pair of angular contact bearing is this type of installation is employed. 5. Change the structure of shaft end tooling to reduce a value. ( 4) Determination of numerical control lathe bearing span l CNC lathe bearing span l refers to the bearing reaction force between two supporting the distance between the point of application. Reasonable l is one of important condition to obtain maximum static stiffness spindle components. When l = l0, spindle component has the largest stiffness, l0 is the optimal span of spindle components. In the specific design, often as a result of the limitation of structural and l≠ l0? , thereby causing loss to the rigidity of spindle assembly. Reasonable span LNM = ( 0. 75 - 1. 5) L0, usually take l≈ lnm＞l0。 Because D, a certain, the larger the l, bearing the radial runout of radial runout of spindle front end effect is smaller, smaller and more l can vibration. When you need to l than l0, three supporting structure can be used.