On Dynamics Of Crank-Group Driving Mechanism Based On The Elemental Dynamic Balancing

This thesis takes the crank group driving mechanism which is a new kind of transmission mechanism as the research object. The project originates from National Natural Science Foundation Project “Crank Group Driving Mechanism and its element of Dynamic Balance Research”, and the project number is51175313. In the process of motion the unbalance caused by the mass of crank group driving mechanism itself result the vibration of the whole machine, makes the mechanism on the precision and the service life of some components reduced,but also worsen the working environment. In order to enhance or improve the performance of the mechanism, it must solve the problem of vibration in the mechanism, that is the analysis and research of dynamic balance on the this mechanism. The main tasks of this thesis are as follows:(1)The dynamic balance problems about crank group driving mechanism are elaborated, and the causes of this mechanism dynamic unbalance in the process of movement are analyzed. Combined with the special nature of the mechanism motion distribution and structure form, the “unitized dynamic balance”method to solve the problem of dynamic balance of the crank group driving mechanism is introduced, the balance problem of crank group driving inertia force including motion axis is solved.(2)The solution conditions and basic theory of the shaking force in the planar mechanism is outlined, and the concept of crank unit of the crank group driving mechanism is defined, and a balanced method about this mechanism shaking force balance through using crank unit is put forward. Then, the general form of crank group driving mechanism is taken as the research target, the linearly independent vector equations is used and solved, the specific parameters of the counterweight is obtained. Finally, an example is given to show the effectiveness of this method to solve the shaking force.(3)A virtual prototype to meet the vertical and horizontal of crank groupdriving mechanism is designed. Firstly, the main components and auxiliary components are designed and modeled. Then the model is assembled according to the actual motion of the crank group driving mechanism. Entering into the process of establishing the virtual prototype when the 3D prototype of the mechanism model is established. The part unit is defined as the connecting rod,the motion pairs between the connecting rod and drivers is added. Finally the movement simulation on the virtual prototype of crank group drive mechanism is carried on.(4)The simulation analysis of the crank unit is carried on by the ADAMS combining with the theory study of the dynamic balance for the crank unit. The main works are that the horizontal and vertical shaking force and shaking moment of crank unit is analyzed before and after adding the balance block.The innovative point of this paper is to take crank group driving mechanism as the research object, combined with the special nature of the mechanism motion distribution and structure form, the “unitized dynamic balance”method to solve the problem of dynamic balance of the crank group driving mechanism is put forward, a better way to solve the problem of the similar planar mechanism is provided for later. In this article, a rack to meet the transmission shaft in the horizontal and vertical is designed, this work has laid a foundation for the research of consideration that affect the dynamic balance of gravity factors.