Mechanics Analysis On Three Pairs Of Dowel Bar Space Intersecting Axes RCCR Mechanism

Spatial RCCR mechanism is a relatively new coupling structure. It can transfer motion and power between input shaft and output shaft while the angle between the axis of the shafs is very large. Research on the types of mechanisms now is not too deep. The forces of each component of three pairs of RCCR mechanisms has not yet analyzed. For the needs of studying team's research, this thesis does the mechanical analysis of three pairs of RCCR mechanisms on the basis of the team's early study of one pair of RCCR mechanisms.Begun with a simple mechanical model, the static analysis about three pairs of dowel bar spatial intersecting axes RCCR mechanisms is done, that is, without considered the friction of each kinematic pair and the gravity and the inertial force of each component, the constraining forces and constraining moments of each kinematic pair are solved. With the difference between the rotation angles of the input shaft and output shaft, in the solving process, the deformation compatibility relations are found, so that the mechanics statically indeterminate problem of the mechanism is resolved. Theoretical calculations show that the stress state of each component of three pairs of RCCR mechanisms is improved a lot than that of one pair of RCCR mechanisms, and the mechanism has no dead point positions and the steering of the output shaft is also deterministic. Later, the effect of each main parameter of the mechanism on the constraining forces and constraining moments of each kinematic pair is analyzed.The mechanism's rigid model is established with the SolidWorks, then the models of each component are imported into the ADAMS. Flexible body model of each component are established. The mechanism's rigid-flexible model is established by the method of Rigid To Flex. In order to solve the contradiction that the flexible dowel bar's interface node is not always coinciding with the corresponding point of the constraining forces of the cylindrical pair,20 different mechanism's rigid-flexible modle are established, in which input shaft's initial rotation angles are deffrent. The static simulation of the mechanism is done and the results show that the theoretical analysis and simulation results are very consistent.With the difference between the input shaft and output shaft, the output shaft's angular velocity and angular acceleration are obtained and the existence of the fluctuations in the angular velocity of output shaft and that output shaft's angular acceleration is not zero are proved. On this basis, the dowel bar's speed, acceleration and inertial force are obtained. Then the dynamic analysis of the mechanism is done with the Dynamic-Static Method. Dynamics simulation of the mechanism is done and the results show that the simulation results and theoretical analysis are basically the same.