| With the rapid development of aerospace technology,the service environment of the electromechanical equipment of the section is becoming more and more complicated,which makes the rudder of the section experience the operating environment of alternating temperature.As the main drive mechanism of the steering gear,the ball screw pair will generate periodic thermal deformation and stress and strain under the temperature-varying load conditions,which may cause the screw transmission accuracy to decrease,the structure to be damaged,and even the screw to fail and jam.As a result,the service life and reliability of the servo are seriously affected.By studying the thermal characteristics of the ball screw pair,if you continue to carry out accelerated testing and life estimation,you can grasp its accurate time-varying rule of reliability in a short time,and then provide technical support for the development and use of this type of equipment.Therefore,studying the thermal deformation and stress-strain response characteristics of the ball screw pair under temperature change load,and then analyzing the effect of different temperature load parameters on the thermal response of the ball screw pair,has a high engineering reference value and significance.Provide theoretical support and guidance for the establishment of initial acceleration test profile for the servo accelerated life test.At present,most of the research results are mainly based on the thermal analysis of the machine tool ball screw pair under internal heating.There are fewer studies and tests on the ball screw pair under temperature-varying loads.Taking the ball screw pair of the steering gear as the research object,the thermal response and its influence law of the internal heat source and temperature-varying load are studied.The main research contents are as follows:(1)The heat source analysis and calculation of the ball screw pair of the steering gear are performed.The heat source distribution and type of the ball screw pair of the steering gear were analyzed,and the heat source generation method and heat transfer path are clarified.Secondly,according to its heat transfer method,the indirect method is selected as the thermal-structure coupling analysis method of the ball screw pair.Finally,the thermal boundary conditions are introduced and calculated based on the heat source analysis.(2)A finite element model of the ball screw pair of the steering gear is proposed and the method of simulating the nut moving load is explained.Through some appropriate assumptions,the three-dimensional model of the ball screw of the servo is simplified,and the finite element model of the ball screw of the servo is built.The APDL program is written in Mechanical in ANSYS workbench to implement it in the form of command flow to achieve a moving heat source for the nut.(3)The thermal response of the ball screw set of the servo under the action of the internal heat source is analyzed.Taking the ball screw pair of the servo as an object,the temperature rise characteristics of the ball screw pair under the determined operating conditions and different speeds are studied and analyzed according to the established simulation analysis method.Then,according to the thermal-structure coupling simulation method,the thermal deformation,thermal stress and thermal strain of the ball screw under the action of the internal heat source are obtained.(4)The thermal response of the ball screw pair of the servo under the action of ambient temperature-varying load and internal heat source is studied.By applying the temperature-varying load as a surface load,the thermal response of the ball screw under the combined effect of the ambient temperature-varying load and the internal heat source is obtained.Secondly,the effect of different temperature-varying load parameters on the thermal response of the ball screw is studied.This study can provide reference and support for the initial acceleration test profile design of subsequent servo accelerated life tests. |
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