Machining rack and pinion using aluminum material

In the process of processing aluminum parts, the processing gear racks are used for long-distance transmission, because in short distances, most of them are directly driven by lead screws, screw nuts, belts, and gear pairs, which requires a combination of various transmissions. way to consider.

In the design of large-scale machine tools, due to the relatively long walking distance of the x-axis, the processing of aluminum parts is rarely driven by ball screws common to other axes, but rack and pinion transmission is selected, as shown in the figure, because the long distance The lead screw will sink under the action of gravity, and the processing of aluminum parts has extremely high requirements on the material of the lead screw, and the cost is huge. Therefore, most of the large floor boring and milling machine tools for processing aluminum parts also use rack and pinion for X-axis transmission.

According to the processing method of precision aluminum parts, the advantage of rack and pinion transmission is that the rack can be extended segment by segment. But simply looking at this transmission method also has its fatal weakness, that is, its transmission speed ratio is small, the walking is fast, the gap is large, and the transmission quality is poor.

In order to achieve a larger speed ratio, the machining of aluminum parts using machine tools will reduce the diameter of the meshing gears as much as possible according to the precision CNC machining method, so as to improve the sensitivity of the transmission. But another point is its backlash, which must be excluded. Recently, there is a mature technology to avoid this shortcoming, that is, the double gear is preloaded in both directions. No matter which direction it runs, there will be an aluminum machining gear. It is tightly meshed with the rack.