中走丝线切割机床的导轮是十分关键的零件关系到切割质量，也是必不可缺少的，所以对导轮的要求比较高，下面我们来说说导轮运动组合件的要求。
1. the V-shaped groove surface of the guide wheel shall have high accuracy. The arc radius at the bottom of the V-shaped groove must be less than the radius of the electrode wire selected to ensure that the electrode wire will not move axially when moving in the guide wheel groove.
2. Under the condition of meeting certain strength requirements, the mass of the guide wheel shall be reduced as much as possible to reduce the sliding friction between the electrode wire and the guide wheel when the electrode wire is reversed. The working surface of guide pulley groove shall have enough hardness to improve its wear resistance.
3. After assembly, the guide wheel shall rotate easily and flexibly to minimize the axial movement and radial circular runout.
4. Carry out effective sealing to ensure the normal working conditions of the bearing.
there are three main structures of guide wheel motion assembly in WEDM: suspended powder support structure, double support structure and double shaft tip support structure. The following is a brief introduction to the characteristics of these three structures.
1) cantilever support structure, simple structure and convenient threading. However, due to cantilever support, the movement stability of the tensioned electrode wire is poor, which is difficult to maintain high motion accuracy, and also affects the service life of the guide wheel and bearing.
2) the double support structure is that the guide wheel is in the middle and the two ends are supported by bearings. The structure is complex and the threading is troublesome. However, this structure has good motion stability, high stiffness, and is not easy to deform and jump.
3) double shaft tip support structure. Both ends of the guide wheel are machined into a 30 ° tapered shaft tip with a hardness of more than 60HRC. The bearings are made of ruby or tin phosphor bronze. The structure is easy to ensure the coaxiality of the guide wheel movement assembly, and the axial movement and radial circular runout of the guide wheel can be controlled in a small range. The disadvantage is that the friction of the shaft tip moving pair is large, and it is easy to heat and wear. In order to compensate the wear of the shaft tip moving pair, the spring force is used to make the moving pair in good contact. In addition to wire cutting, some guide wheel supports also adopt sliding support structure.
it is necessary to select a suitable guide wheel for WEDM processing, so buyers need to pay attention to the quality of the guide wheel when purchasing.
