Kinematic Characteristic Analysis And Parametric Design Of Cageless Ball Bearing With Collision Reduction Groove

Cageless bearings have the characteristics of tight structure,high bearing capacity and strong impact resistance.They are used in many fields such as aircraft,gyroscopes,spare bearings of maglev bearings and so on.And cageless bearing adjacent to the collision friction between the rolling element has been affecting the stability of bearing movement,in order to solve the above problems,the same group proposed a new type of cageless bearing with reduced collision groove to make the rolling element uniformly discrete.In this thesis,the motion characteristics of cageless bearing with reduced collision groove are studied from the perspective of dynamics,based on which a series of bearing parameter database is established to realize the parametric design of bearings.Firstly,the motion of the rolling element of the cageless bearing with collision reduction groove is analyzed,and the relationship between the motion of the rolling element under the two different motion states of pure rolling and rolling sliding is established respectively.On the basis of this,the equation of the velocity change when the rolling element passes through the collision reduction groove is established,and the relationship between the motion parameters of the rolling element and the structure of the collision reduction groove is determined.Analyze the contact state between the rolling element and the conventional raceway and the partial collision reduction groove,and establish the interaction force model between the rolling element and the raceway,and between the rolling element and the rolling element.Combined with the motion of the rolling element to establish the collision contact model between adjacent rolling elements,determine the relationship between the collision force between adjacent rolling elements and the rolling element surface contact deformation equation.On the basis of the above research,establish the dynamics model of cageless ball bearing with collision reduction groove,which provides the theoretical basis for determining the motion characteristics of rolling element and giving its angular velocity of revolution,angular velocity of rotation,collision and slippage law.Secondly,this thesis develops a dynamics solution program in Matlab software based on the fourth-order Lundgren-Kutta method with adaptive step size,numerically solves the established dynamics model of cageless ball bearing with collision reduction groove,determines the change of the rolling element motion characteristics with time,and analyzes and discusses this law,further determines the correlation between the angular velocity of the rolling element rotation,angular velocity of rotation,collision and slip,and further determines the region where the rolling element is prone to slip.Based on the numerical solution,the collision of the rolling elements at different positions of the collision reduction groove and the trajectory of the inner ring of the bearing are obtained,the displacement-displacement and velocity-displacement phase diagrams of the inner ring are analyzed,and the collision law between adjacent rolling elements is combined to make a preliminary selection of the position of the reduction groove;on the basis of the above study,the collision law between adjacent rolling elements of collision reduction groove bearing with different parameters is analyzed,and the optimum parameters of the collision reduction groove are finally determined.Finally,according to the selected structure and parameters of the reduction groove,the parametric design of the cageless ball bearing is carried out according to the motion of the rolling element and combined with the inner and outer rings of the standard bearing,and a database of bearing related parts and parameters of the reduction groove structure is established.Based on C# programming language,the operating interface is designed and combined with Solidworks software to realize the parametric design of the bearing.In order to verify the correctness of the theoretical analysis and numerical results,the bearing test platform is built with a high-speed camera to collect images of the rolling element motion in the bearing,and the image processing program is written using Matlab software to determine the angular velocity of the rolling element rotation.The experimental results are compared with the theoretical study to verify the correctness of the theoretical analysis.In this thesis,the kinematic characteristics of cageless ball bearing with collision reduction groove are studied to determine the law of the rolling element motion and the influence of the position and parameters of the collision reduction groove on the collision between adjacent the rolling elements.The research in this thesis has important implications for the analysis,design and application of cageless ball bearing dynamics.