Аннотация:The paper presents some research results of dynamic processes taking place in vacuum contact devices of mobile wall climbing robots. Vacuum generation is considered in robot's devices contacting with surfaces having nonpredictable quality. Calculation method of such parameters as forces, pressure, flow, is delivered for system that consists of ejector connected with a chamber of vacuum contact device. Calculation is based on main equations of current flows such as conservation of mass, momentum and energy. Robots with vacuum contact devices have better possibilities to operate in extreme conditions at all stages of motion. Experimental results are discussed.