精密钢球传动减速机构的瞬时接触热特性分析

Analysis on Instantaneous Contact Thermal Characteristics of Reducing Mechanisms for Precision Ball Transmissions

基于Hertz接触理论,以精密钢球传动减速机构为研究对象,建立了减速机构啮合副齿面接触分析模型。分析了钢球与摆线槽齿面间的瞬时接触域,在此基础之上,分析输入轴转速、负载对减速机构热特性的影响,得到钢球与齿面间接触域的瞬时生热率和瞬时摩擦温升。分析结果表明:钢球与摆线槽齿面的瞬时接触域是时变接触椭圆;输入轴转速和负载对瞬时生热率和瞬时摩擦温升都有明显影响,但转速的影响更大;瞬时摩擦温升在常规转速下随转速单调递增,在超低转速下随转速先递减再递增。研究结果为精密钢球传动的三维热力耦合分析奠定了理论基础。

Based on the Hertz contact theory, a tooth surface contact model was established forward to analyze the instantaneous contact areas and thermal characteristics of reducing mechanisms for precision ball transmissions. The contact patches among the balls and tooth surfaces of cycloidal groove were analyzed, then the effects of the input shaft speeds and loads on the thermal characteristics of reducing mechanisms were investigated. Instantaneous heat generation rates and instantaneous frictional temperature rises among the balls and tooth surfaces were obtained. The results indicate that the instantaneous contact areas among the balls and tooth surfaces of cycloid groove is a time-varying contact ellipse. The input shaft speeds and loads have visible influences on instantaneous heat generation rates and frictional temperature rises, but the influences of speeds are greater. Instantaneous friction temperature rises are monotonically increasing with the increased speeds under the general speed conditions, but in the low speeds, temperature rises are monotonically decreased and then monotonically increased. The results of the study provide a good foundation for three dimensional thermal mechanical coupling analyses of precision ball transmissions.