Dynamic Characteristic Analysis Of Ball Bearing Used In Reaction Flywheel

As the rapid developing of the modern society technology,a series of great progress have been achieved on the aerospace technology.However,with the development of the aerospace technology and complexity of the spacecraft,some bottlenecks also have emerged.The researchers have focused on the lifetime of the spacecraft for half a century.It is daily enhanced to have the requirements of the spacecraft for the high accuracy and stable controlling,long lifetime reliable service and rapid movement.And how to improve the lifetime of the spacecraft has become a new problem.In this problem,the controlling type of the satellites is the main factor.For the traditional controlling type,jet controlling,it will be useless in case of the used up of the jet while the momentum wheels can be used to solve this problem that has been applied in controlling of the satellites at present.Though the momentum wheels have been widely accepted,the complexity of the wheels and the lifetime are the key problem of the using of momentum wheels.In this paper,a dynamic model,a starting up model and an ADAMS simulation model of the bearing have been built which were used on the reaction flywheels,and to study the force state,the skipping and the cage stability.The parameters of the bearing will be optimized under the study and provide the guide for the using of the bearing.The quasi-dynamic model of the bearing has been built in this paper.And the contact angle,the film thickness and contact stress between balls and rings will be achieved.At the same time,the effects of the groove curvature coefficients,rotating speed and axial forces on the dynamic characteristic behavior are studied for the parameters optimization.And the results will be compared with the rotating of the inner ring.Through the studies,there is a big difference between the rotating of the outer ring and inner ring which was caused by the bearing clearance increasing because of the centrifugal force.The starting up model of bearing has been built to study the rotating speed,skipping,sliding speed and slip ratio of balls under the changes of the angular acceleration.The results show that the following of the balls decreases with the increasing of the angular acceleration while the slip ratio and skipping increase.And the condition becomes more serious when the outer ring rotates compared with the rotating of the inner ring.A multi-body dynamic model has been built through the ADAMS software in order to study the effects of the angular acceleration,axial force and the shape of the cage pocket on the cage stability.The results show that the decreasing of the acceleration,axial force and increasing the circumferential clearance of the cage pocket are all benefited to the cage stability.