双排非对称四点接触球转盘轴承力学性能分析

Mechanical Properties Analysis of Asymmetric Double Row Four-point-contact Slewing Bearing

接触角是轴承设计的一个重要参数,它直接影响轴承的变形、受力和寿命等特性。随着轴承空间限制和高承载能力的目标要求,对传统负游隙对称型(α01=α02=45°)双排四点接触球转盘轴承进行改进,提出非对称型接触角设计(α01=35°60°,α02=90°-α01),并建立非对称双排四点接触轴承的力学模型,分析非对称接触角对轴承载荷分布、轴承刚度和承载能力的影响。结果表明:随着非对称接触角的增大,非对称双排四点接触球转盘轴承四点接触球个数先减小后增大,轴承的最大接触载荷先减小后增大;单向载荷作用下,随着非对称接触角的增加,轴向刚度Kaa不断提高,径向刚度Krr和角刚度Kθθ在非对称接触角为60°时最大,45°时最小。联合载荷条件下,非对称接触角为45°和50°时的主刚度明显小于其它非对称接触角情况,辅刚度具有明显的对称性;在轴承正常工作区域,随着非对称接触角α01的增加,轴承的静承载能力基本呈下降趋势,以轴承静承载能力为选型指标可取非对称接触角α01=35°,α02=55°。

Contact angle is an important design parameter of rolling bearing.It obviously affects the deformation,contact stress and working life of rolling bearing.Currently,the bearing space is limited,but load carrying capacity of the bearing is higher.In the paper,a new design of asymmetric contact angle(α01=35°60°,α02=90°-α01)double row four-point-contact slewing bearing is proposed based on the normal negative clearance and symmetric contact angle(α01=α02=45°)type.In order to accurately investigate the influence of the asymmetric contact angle on the load distribution,stiffness and carrying capacity,the mechanical model of the asymmetric double row four-point-contact bearing is firstly established.The results show that with the increase of the asymmetric contact angle,the number of four-point contact balls decreases at first and then increases,the maximum contact load of the bearing firstly decreases and then increases;under the action of one direction load,with the increase of the asymmetric contact angle,the axial stiffness Kaa of the bearing increases,the radial stiffness Krr and angular stiffness Kθθare the largest when the asymmetric contact angle is 60°,and are smallest when the asymmetric contact angle is 45°.Under combined load conditions,the main stiffness at asymmetric contact angles 45°and 50°are significantly smaller than that at others.The auxiliary stiffness has obvious symmetry.Under the normal operating conditions,with the increases of the asymmetric contact angleα01,the static carrying capacity of the bearing present a downward trend.Taking the static carrying capacity as the performance index,the asymmetric contact angleα01=35°,α02=55°is suitable.