| Aiming at the problem that the power quality ratio of the gear transmission is low and the transmission ratio of the single pump-single motor hydraulic transmission device is not accurate,a multi-pump(double-stator multi-output pump)-multi-motor(double-stator multi-speed motor)hydraulic transmission is proposed.Due to the special structure of the double stator,the multi-pump can realize the multi-stage output of the flow,and the multi-motor can realize the multi-input of the flow.So the change of the transmission ratio can be realized by combining the multi-pump/ multi-motor flow output/input form.The new hydraulic transmission has no variable mechanism,and the transmission ratio is only related to the displacement of the pump and motor,so the transmission ratio is accurate.First of all,the development and application of several kinds of variable speed transmission mode were studied.Mechanical transmission has high reliability and low power density.Hydraulic drive has wide applications range but low efficiency ineffective.Electrical transmission has the advantage of energy saving and environmental protection but need to be developed.Hydraulic transmission is stable,and has high power density,mature technology and other characteristics,so it will continue to develop.Secondly,on the basis of the existing hydraulic transmission circuit and multi-pump-multi-motor closed system,the transmission circuit of the new hydraulic transmission is studied,and the output speed/torque/power of the hydraulic transmission under constant load and constant power is analyzed and calculated.At the same time,the output speed characteristics and control mode of the new hydraulic transmission with variable speed control are studied by theoretical analysis and AMESim simulation.In order to achieve various work forms of multi-pump-multi-motor transmission,and reduce the number of parts as much as possible,achieve integration,a combination mechanism is proposed to achieve the combined function,which achieved original by multiple directional valves.According to the overall structure and the circuit connection forms of the new hydraulic transmission,the paper has studied the structural design and force analysis of it.Then,the three-dimensional modeling of the combination mechanism is carried out,and the internal flow path is simulated by Solid Works Simulation to obtain the pressure and velocity flow graphs at different positions.Finally,the prototype of combination mechanism is processed,and the experimental system of the new hydraulic transmission is designed by using the existing multi-pump-multi-motor test-bed,which used to verify the rationality and feasibility of the research. |
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