新型无保持架球轴承纯滚动设计及动态特性分析

Design and Dynamic Characteristics Analysis of a Novel Cageless Ball Bearing with Pure Rolling

为了解决高速轴承打滑和保持架易断裂失效的问题,从轴承的轴向和径向角度出发,提出一种纯滚动无保持架球轴承设计方法,并通过实例对其正确性和有效性进行了验证。本方法首先根据摩擦学理论,确定轴承纯滚动边界条件,引入轴向摩擦角概念,通过径向游隙和滚道母线分别限定滚动体的径向和轴向位移,使得滚动体与滚道之间形成摩擦自锁效应,将滚道中滚动体复杂的运动形式化简为单一的纯滚动,取消保持架的同时增大了滚动体容纳量。其次,将径向游隙映射到轴承内外圈滚道母线设计中,建立基于轴向摩擦角的无保持架轴承滚道母线计算模型和设计原则。最后,提出一种基于上述方法设计的新型无保持架轴承结构,内外圈滚道母线采用对数螺旋线设计,并通过轴承特性试验评价其动态性能。结果表明,该新型轴承能够实现近纯滚动,以滚动摩擦代替滑动摩擦,大大降低了轴承的摩擦热问题,显著提高了轴承的极限转速。在3 kN轴向载荷作用下,轴承的极限转速为32000 r/min,DmN值可达到2.8×106 mm·r/min。在20900 r/min转速下,轴承可承受20 kN的轴向载荷,具有较高的承载能力,能够满足航空航天、国防军事等技术领域对高承载、高转速轴承的应用需求。

A pure rolling cage-free ball bearing design method is proposed from the axial and radial perspectives of the bearing to solve the problems of high-speed bearing slippage and cage failure.Its correctness and effectiveness are verified by example.This method is first based on tribological theory to derive the pristine rolling boundary condition of the bearing and introduces the concept of axial friction angle.The concept of axial friction angle is introduced.The radial and axial displacement of the rolling body are limited by the radial clearance and raceway bus,respectively.The raceway's complex form of rolling body motion is simplified to a single pure rolling,and the cage is eliminated while the rolling body capacity is increased.Thus,the radial clearance is mapped to the design of bearing inner and outer ring raceway bushes,and the calculation model and design principle of raceway bushes of cageless bearings based on axial friction angle are established.Finally,based on the above method,a novel cageless bearing structure is proposed with a logarithmic helix design for inner and outer ring raceways.Its dynamic performance is evaluated by bearing characteristic test.The results show that the novel bearing can achieve nearly pure rolling,replacing sliding friction with rolling friction,significantly reducing the frictional heat problem of the bearing,and significantly increasing the permissible maximum speed of the bearing.Under 3 kN axial load,the ultimate speed of the bearing is 32000 r/min,and the DmN value can reach 2.8×106 mm·r/min.At a speed of 20900 r/min,the bearing can withstand an axial load of 20 kN and has a high load-carrying capacity.It can meet the application requirements for high-load and high-speed bearings such as aerospace,defense,and military.