The Study Of Mixing Mechanism Of Mixing Drum And Hydraulic Driving For Cement Mixing Truck

The development of commercial concrete radically changed the backward production method of mixing cement by self, and transporting to site by tip lorry and dump truck, and utilized near-by, this created a new way of production, i. e. the concretes needed on several jobsite can be produced by specialized cement mixing plant or large scale concrete mixing station, and formed a supply network centered by cement mixing location. Due to the modern electronic control and computer system, the products can be obtained with precise proportioning and uniformity, the concrete quality can be improved greatly, furthermore, the whole project can be prompted with a fine development. But the centralized and commercialized concrete production also generates problems, like situated far from jobsite, sometimes too far, and enlarging transporting distance. When the distance ( or time ) extended to a certain extent, the concrete could be sedimented to layers if it is transported by normal vehicles, or pre-concreted, it influence the final concrete quality, this is not acceptable. In order to transporting the cement properly, cement mixing truck was developed as a right tool. This kind truck not only can mix cement, but also transport them, so both functions can be achieved during traveling, so the quality of concrete can be ensured, and the distance (or time ) can be extended.The mixing and unloading function of cement mixing truck are the turning of two screw blades inside the mixing drum, the cement can be droved in both axial and tangential direction, so the shape of helix line of two screw blades and its structure directly influence its performance.This study analyze theoretically screw blades for its working principle in the aspects of statics and kinematics, and provided theoretical bases for designing the structure of screw blades. Through the establishment of kinematical module, the mixing procedure of drum is analyzed dynamically, so kinematic module was set up for mixing drum, it can be served for designing mixing drum.The mixing drum is not only transporting vessel for mixing cement, but also working part for mixing during traveling, so its configuration of driving unit, design and calculation of transmission system, are the key point. This paper dealt with the detailed analyses and calculation for variable volumetrical stepless hydraulic system which are used very largely for mixing truck domestically and abroad.