Analysis Of Hydrodynamic Characteristics Of Hybrid Sliding-bearing With Spiral Groove

With the rapid development of transportation,electric power,aviation and other industries,rotating machinery plays an increasingly important role.As the basic part of the rotating machine,the bearing guarantees safe and efficient operation of the rotating machine.In this paper,based on the bearing of a certain type of sodium-cooled fast reactor coolant pump,the journal of the bearing is worn due to insufficient bearing capacity.A hybrid sliding-bearing with a spiral groove on the shaft surface is proposed to discuss the feasibility of this bearing.The specific work and conclusions are as follows:(1)A dynamic and static sliding-bearing with a spiral groove is proposed.The hydrodynamic characteristics of the bearing clearance of the spiral groove sliding-bearing are analyzed.The flow state of the fluid in the gap of the spiral groove sliding-bearing under working condition is discussed.(2)Based on the Fluent software,the advantages and disadvantages of the grooving position were studied and the primary and secondary relationships of the spiral groove structure parameters(helix angle,number of heads and the ratio of groove table width)on the static characteristics of the sliding bearing were discussed.The results show that the angle of spiral groove is a significant factor influencing the support force and the offset angle;The significant factors affecting the leakage are the angle of the spiral groove and the ratio of groove table width;the number of spiral heads has no significant effect on bearing performance parameters.(3)An improved eddy dynamics model is proposed.Then,the simulation data is processed by linear fitting,and it is found that the correction coefficient is very close to 1,indicating that the model is reasonable.Based on this,the influence of eccentricity and rotational speed on the dynamic characteristics of the bearing is studied.The research shows that as the speed and eccentricity increase,the main parameters of the bearing in all directions increase.(4)The fluid-solid coupling calculation method based on dynamic mesh technology is proposed to calculate the nonlinear axis trajectory of the sliding-bearing model.The influence of initial eccentricity and rotational speed on the axis trajectory is studied.It is found that the center of the shaft will eventually converge to the center of the bearing bush over a period of time without external load.Combined with the results of the eddy analysis,it is concluded that the dynamic and static sliding-bearing with the spiral groove on the surface of the shaft can theoretically avoid the abrasion.