Research On Direct Drive Cylinder System Of Small Compressor

Although the centralized air source has been widely used to supply compressed air for pneumatic system, it is uneconomical to use the centralized air source, when there is only one or two actuators to drive and no other driving methods can be used to instead this pneumatic driving way. So it is necessary to take the small independent air source into consideration. Whether a small air compressor can be used to replace the centralized air source has not been determined, in order to meet the need of pneumatic driving way and to save the basic cost of the system. The driving characteristics and the working conditions of the cylinder system directly supplied by a small air compressor are needed to be researched. In this paper, with the help of theoretical analysis and the experiments, the cylinder system which directly supplied by a small air compressor has been researched and compared with the cylinder system supplied by the centralized air source, in order to make sure whether the cylinder system directly supplied by a small air compressor can be put into use when it fulfil the actual working conditions.The main research work in this paper is as following:1. Based on the actuator of cylinder, three different basic configuration circuits of the cylinder system directly supplied by a small air compressor are built. The matching relations between the components of the circuits, the cylinders and the small air compressor are discussed to provide a reference for building the cylinder system directly supplied by a small air compressor properly. The related mathematical model is established. The relationship between the volume of the small tank and different air displacements of air compressor as well as the radius of the cylinder is calculated.2. According to the parameters and the actual requirements of the experimental cylinders, the suitable piston-type small air compressor is chose. A constant axial loading mechanism is manufactured for the cylinder system, which can cover a larger range of working load that 33 times more than the loading trolley. Two different experimental systems are built and the experiments are conducted.3. The relative driving characteristics of cylinder systems directly supplied by a small air compressor and centralized air source are obtained and analyzed. The minimum cylinder outer stroke time of the former system is 0.1～0.15 second more than the system supplied by the centralized air source. And the speed stability of the former system is 23.6%～61.5% of the latter system. The load has a bigger effect on the working frequency of the cylinder system directly supplied by a small air compressor than the latter system for one minute. In the meantime, the optimal control method is studied to make the best use of the cylinder system directly supplied by a small air compressor.4. The comparisons of the energy consumed and the cost of the two cylinder systems supplied by differ air sources are made. The power ratio and cost ratio concept are put forward as the assessment criteria of the energy consumption and system economy. The power ratio of former system is 1.71%～4.04% of the latter one, and its cost ratio is about 1/40 of the latter one. So the cylinder system directly supplied by a small air compressor has a great economic advantage.Based on the study and comparison of the two cylinder systems supplied by different air sources, the following conclusions are obtained:Compared with the cylinder system by the centralized air source, the cylinder system supplied by a small air compressor has its advantage, it has fewer components, lower cost and less energy consumption. Its speed stability and working conditions can meet the basic working requirements of the cylinder. But when it needs to improve the speed stability and expand the working conditions, the cylinder system supplied by a small air compressor will be failed to fulfil the working requirements.