A centerless grinder is a type of grinding machine that does not require the positioning of the axis of the workpiece to perform grinding. It is mainly composed of three mechanisms: a grinding wheel, an adjusting wheel and a workpiece support. The grinding wheel actually performs the grinding work. The adjusting wheel Control the rotation of the workpiece, and control the feed speed of the workpiece. As for the workpiece support to support the workpiece during grinding, there are several ways to cooperate with these three parts, except for stopping grinding, which are the same in principle.
A grinding machine that uses a centerless grinding method to grind the rotating surface of a workpiece is usually a centerless cylindrical grinding machine. On the centerless cylindrical grinder (see picture), the workpiece is not centered and supported by the top, but is placed between the grinding wheel and the guide wheel, supported by the pallet and the guide wheel. The grinding wheel is generally installed at the end of the spindle, and the grinding wheel with a width greater than 250 mm is installed in the middle of the spindle. The maximum width of the grinding wheel can reach 900 mm. The grinding wheel rotates at a high speed for grinding, and the guide wheel rotates in the same direction at a slower speed, driving the workpiece to rotate for circular feed. During through grinding, the axial feed is achieved by adjusting the slight inclination angle of the guide wheel axis, which is suitable for grinding slender cylindrical workpieces, short shafts without central holes, and sleeve workpieces. During plunge grinding, the radial feed is realized by the movement of the guide wheel holder or the grinding wheel holder, which is suitable for grinding workpieces with shoulders or bosses, as well as cones, spheres or other workpieces with curved lines. Centerless grinders have high productivity and are easy to automate with various loading and unloading devices. They are mostly used for mass production and can be operated by unskilled workers. The grinding accuracy of centerless grinders is generally: roundness of 2 microns, dimensional accuracy of 4 microns, high-precision centerless grinders can reach 0.5 microns and 2 microns respectively. In addition, there are centerless internal grinding machines and centerless thread grinding machines.
The centerless grinder can automatically dress and compensate automatically. The guide wheel feed rail is a double V-shaped needle roller guide wheel, which is fed by a servo motor and can compensate each other with the dressing of the grinding wheel. The machine tool is equipped with an automatic loading and unloading mechanism, capable of automatic circular grinding.
