三马致力于打造优质传动设备蜗轮蜗杆

Measuring distance method of copper worm gear

Measuring distance of measuring ball of copper worm gear (M value for short) refers to the outer dimension measured along the radial direction on average by putting one or two steel balls into the groove of copper worm gear; it is mainly used for measuring the tooth thickness of copper worm gear. As the tooth thickness of copper worm gear has a direct impact on the transmission backlash, the new national standard "Cylindrical Worm and Copper Worm Gear Accuracy" (GBIO089-88) has formally included the deviation of tooth thickness of copper worm gear in the stipulated items, and defined it as the difference between the actual value of indexing cylindrical tooth thickness of copper worm gear and the nominal value. But there is no direct measurement of the thickness of the copper worm wheel. It is also difficult to use the existing tooth thickness caliper or the common normal micrometer to measure the normal direction. Only the indirect method of measuring pier with steel ball is easy to realize in production and can achieve high precision. So it is almost the best choice of the current tooth thickness deviation measurement method. The calculation of measuring sphere distance is the key to realize this method. Some calculating methods of measuring sphere distance for copper worm gears in linear worm drive have been put forward as early as the 1950s. However, more and more copper worm gears with disk cone and enveloped cylindrical worm drive are used. The calculating method of measuring sphere distance has not yet been published. The purpose of this paper is to provide a convenient and reliable method for calculating the M value of the copper worm gear of this kind of worm drive. Suppose that the radius of the circle in which the sphere center is located is RC (figure) after the steel ball is placed into the groove of the copper worm gear and reaches the equilibrium position under the action of force measurement. The RC can be solved by iteration method according to the formula derived in this paper. The accurate formula for calculating the measuring distance of the sphere of the copper worm gear in the disk conical enveloped cylindrical worm drive is given by strict mathematical derivation. Indirect measurement of thickness deviation of copper worm gear teeth.