CNC lathes can effectively rough and finish various casting, forging and welding high-strength ferrous and non-ferrous metal parts. It can process inner and outer cylinders, inner and outer conical surfaces, inner and outer spherical surfaces, grooves, planes, threads, surfaces of revolution, drum cams, plane cams, etc. Bearing seats, sleeves, transition rings, manhole flanges, ball sleeves, etc. are typical processing parts.
The working state of the beam of the ordinary CNC lathe: the beam is driven by the trapezoidal screw, the lifting box is placed on the column, and the power is transmitted to the screw by the AC motor through the worm gear pair. After the position of the beam is determined, clamp it in the front, back, left and right directions, first left and right, then front and back. The clamping force of the beam comes from the hydraulic cylinders at both ends of the beam. The clamping device is similar to a rack and pinion mechanism. The rack and pinion movement realizes the up and down movement of the beam. When the beam moves to the desired position, it is fixed with a pressure plate.
Although hydraulic transmission has many advantages, it is inevitable that oil leakage occurs in long-term use of hydraulic mechanism. Therefore, when most CNC lathe manufacturers in my country make mechanical transformations on the beam lifting mechanism, they usually remove the screw of the original machine tool and replace it with a ball screw, replace the old motor of the original machine tool with a stepper motor, and then replace it. Corresponding structural designs such as the screw nut slider and the bearing also need to increase the self-locking device, the cost of using the ball screw is relatively high, and the total cost of the transformation will also be high.
Starting from actual work needs, through practical exploration, the worm gear transmission mechanism can be directly used, so that the design can not only meet all the actions, but also simplify the equipment control. According to the calculation and verification of the weight of the beam itself and related parts. The self-locking function of the worm gear can meet the strength requirements, the design structure is simple, and the cost is low.
In the design and verification process of the beam transmission mechanism, it is necessary to fully consider the stress of the beam itself, such as the gravity of the beam itself, the weight of the sliding seat, the gravity of the tool holder, the friction force in the movement, etc. The stress of the beam is more complicated. In order to calculate the worm wheel reasonably To design a suitable worm gear, the stress of the beam must be fully considered.