| The swashplate axial piston pump is an important power component in hydraulic systems,with advantages such as high power to weight ratio and flexible variables.It is widely used in engineering machinery,aerospace and other fields.Due to its technological complexity and importance,there is currently a significant technological gap between China and foreign countries,making it one of the important bottleneck technologies in the field.As an important component of a piston pump,the spindle is used to drive and carry the rotation of the heart components.Its deformation,distortion,and other factors directly affect the performance of the three major friction pairs,and are crucial for the stability and service life of the pump.In traditional design,only factors such as bending and torsion resistance under static conditions are considered,without considering the alternating loads borne under dynamic conditions.With the current trend of high voltage and high-speed development,it is no longer possible to meet design requirements.Based on the goal of achieving autonomous control and solving the bottleneck problem,this article conducts research on the dynamic and fatigue characteristics of the spindle,aiming to provide necessary theoretical basis and design basis for the design of the axial piston pump spindle under high-pressure and high-speed working conditions.The main research content of this article is as follows:1.Based on the working principle and structural characteristics of the axial piston pump,the force characteristics and bending and torsional strength of the spindle were analyzed,and the static characteristics of the spindle were analyzed using ANSYS Workbench.Under high-pressure and high-speed working conditions,the hydraulic pressure significantly increases the overturning force of the spindle and the centrifugal force of the plunger component,which has a significant impact on the stability of the spindle operation.In the research process of this article,the overturning force of hydraulic pressure on the main shaft is a spatial force,and the eccentricity of the action point constantly changes with the rotation of the cylinder block component.The centrifugal force of the plunger component also changes with the rotation direction of the cylinder block.Based on the force characteristics of the spindle,the bending,torsional strength,and static characteristics of the spindle were analyzed.2.Establish a multi body dynamic model of the plunger pump through ADAMS,and use ANSYS APDL to treat the spindle with flexibility,replacing the original rigid spindle,to complete the rigid flexible coupling simulation model of the plunger pump.And the accuracy of the simulation model was verified by comparing simulation calculations with theoretical calculations.3.Based on the rigid flexible coupling model,modal analysis was conducted on the spindle and the dynamic characteristics of the spindle were studied,namely the effects of different loads and working speeds on the force,vibration,and deformation of the spindle.The results indicate that the main shaft is subjected to the maximum force in the Y direction because the radial load of the cylinder on the main shaft is applied in the Y direction of the main shaft.The significant fluctuation of force in the Z direction is due to the influence of centrifugal force on the cylinder block components.As the load pressure and rotational speed increase,the force,vibration displacement,and deformation of the main shaft all increase to a certain extent.Through frequency domain analysis,it can be seen that the deformation of the main shaft mainly comes from the vibration of the main shaft,and the vibration energy of the main shaft mainly comes from its own rotational excitation,that is,the high-speed rotation of the main shaft is the main reason for the deformation of the main shaft.The deformation of the main shaft should be less than the fit gap between the main shaft and the cylinder body.High hardness materials can be selected for the connection between the main shaft spline and the cylinder body.4.Under long-term dynamic loads,the spindle will inevitably experience fatigue.The n Code Design Life platform was used to build a fatigue life prediction and analysis process for the spindle,and fatigue life prediction was carried out on the spindle.Match the finite element statics analysis results of the main shaft with the load spectrum,and combine the S-N curve of the material,analyze and calculate the fatigue life of the common materials of the main shaft and the locations prone to fatigue under the extreme conditions.The results show that under extreme operating conditions,the lifespan of 20 Cr,40Cr,and 20 Cr Mn Ti materials exceeds the warranty period of the plunger pump,which can ensure the safety and reliability of the pump.The main shaft is prone to fatigue at the location of stress concentration,and stress concentration should be avoided as much as possible during design. |
