Study On The Simulation Experiment Of Multi-rod Spatial RCCR Mechanism

For most of the studies on spatial RCCR mechanisms, they ignored some of the factors to solve over constrained mechanism by making all parts flexible or adding denaturing compatibility equation, the results do not reflect the way bodies performs under rigid conditions. This paper creates a bushing force connected rigid body model in COSMOSMotion. This paper is based on the mechanics of materials and principle of the flexible body kinematics to analyze the dynamics of spatial RCCR mechanisms, and selects the appropriate model of spatial RCCR mechanisms to perform the simulation under ideal conditions without the friction, the following aspects are the results:1) The increasing rods’ number would influence the value of constraint forces. This paper has simulated the model by selecting appropriate conditions and parameters, integrated and analyzed the data, then drawn a graph and found that with the number of rods increases, the constraint force along z axis decreases while the torque transmitted is constant; constraint forces along X and Y axis does not transmit the torque, so the forces stay unchanged. The mechanism operates relatively stable along each direction, and the sum of the forces on each rod in the same direction is0N. Thus prove that the mechanism does not need to add extra support to make it stable during operation2) Changes of offset in the mechanism affects constraint forces. Analysis of the simulation data of multiple models and graphics made from the data show that constraint force values along Z axis become smaller while the offset on the wheel increases; constraint forces along X and Y axis increases as they are only influenced by the centripetal force. This mechanisms need to take offset into consideration as it may impact the operation.3) Changes of the angle between the power transmission shafts affect constraint forces. The simulation performed with different axis angles and comparison of force graphs drawn from the analog data show that with torque stays the same, the constraint reaction forces angle X and Y axis decrease while the angle increases; the constraint force along Z axis stays same. Power transmission shaft angle has an impact on the mechanism.4) The analysis of the main way the power transmits, take the example of the model with shaft angle of90°, simulate the spatial RCCR mechanism, and analyze the simulation data to draw the graphs of instantaneous power and power accumulated of the cycle, it shows that the mechanism relies on the constraint force along Z axis to transmit power; constraint forces along X and Y axis do not transmit power. This chapter analyzes the process of power transmission and accumulation along all axes qualitatively.