| The precision ball transmission is a precision actuator by using cycloid ball reducermeshing pair and ball equal speed meshing pair. In the process of transmission, theagency’s outstanding advantages is no backlash and high transmission efficiency, it iswidely used in many areas, such as aviation and spaceflight, NC machine tools, robot,precision machinery and so on.Because the cycloidal slot section is V groove, in the process of transmission, themeshing style between steel ball and cycloid groove always maintain the four-pointcontact transmission, due to micro sliding will cause sliding friction, if sliding friction isaccumulated after a long time, it will result in wear clearance and interference of thermalexpansion, thus it will affect backlash and normal meshing, therefore the skidcharacteristics of the cycloid ball meshing pair t is studied deeply in this paper,friction-wear behave and frictional heat of the meshing pair is further discussed and indetail analyzed.On the base of the relationship between curve radius formula of epitrochoid grooveson central disc and hypotrochoid on planetary disc, and combined with itsconvex-and-concave feature, the engagement position of steel ball and cycloidal groove indifferent time can be obtained. The movement of the cycloid ball meshing pair is shown ina periodic property. At the same time, the load and stress formulas and variationalregularity corresponding to engagement position are presented by using the hyperstaticmethod and elastic Hertz theory.According to the principle of relative movement and transformation of mechanism, inthe process of operation, arc length difference’s existing proves that the form of cycloidball engagement pair is slide-roll mixed state. A theoretical investigation on kinematicsrelationship of cycloid ball engagement pair is carried out to obtain the expressions ofrelative sliding velocity and sliding rate, variational regularity corresponding toengagement position is presented and three-dimensional of model cycloid ball engagementpair is established by using UG software, at the same time, combined with ADAMS software, kinematic simulation is carried out.Friction torque and the approximate calculation method of the wear is deduced, underdifferent stress distribution, the situation of steel ball wear is analyzed, furthermore, theexpression of the friction temperature caused by the sliding friction is obtained, theinfluence of different design parameters on the friction temperature is also studied. |
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