引信自旋式微电机旋转机架抗高过载结构设计

Design of Structure Resisting High Overloads for Spinning Micro-Machine's Rotating Rack in Fuse

针对炮弹发射过程中的瞬时高过载造成弹道修正引信自旋式微电机旋转机架失效,导致引信无法正常工作的问题,结合当前弹载器件抗过载的主要方法与思路,考虑电机旋转机架的工作特点,根据旋转机架动力学模型和轴承在缓冲设计条件下的吸能原理,基于弹-炮-引信耦合有限元动力学仿真获取了旋转机架轴承的过载特性,结果表明了轴承主要承受轴向过载条件下的惯性力冲击.在此基础上,提出了在轴承处添加铜制缓冲垫片和改变外转子机架的轴肩与底螺尺寸两种抗过载设计方案,并通过弹-炮-引信耦合有限元动力学仿真分别获取了两种方案下球轴承最大应力值随时间的变化.结果表明,添加铜制缓冲垫片无法将球轴承的最大应力降低到轴承钢屈服极限以下,而通过改变外转子机架轴肩与底螺尺寸能成功将球轴承的最大应力值降低至轴承钢屈服极限以下,结合推力轴承形变量判定,该方案满足旋转机架的抗过载设计需求,保证了修正引信在炮弹发射后的正常工作.

Instantaneous high overload that appears during projectile s launch process always results in the failure of spinning micro-machine s rotating rack used for trajectory correction fuse,rendering the fuse unable to work normally.In view of such a problem,combined with the design method of resisting overloads for onboard device,based on the rotating rack s dynamic model and bearing s energy absorption principle under the condition of buffer design,the bearing s overload characteristic was acquired through finite element dynamic simulation based on projectile-barrel-fuse coupling with the operating characteristic of machine s rotating rack concerned.The results indicated that the axial inertial force was the main load imposed on bearings.On this basis,two schemes,adding the buffer made of copper and changing the size in shaft shoulder and bottom bolt,were proposed.Then the ball bearings maximal stress variation during projectile s launch process was acquired by finite element dynamic simulation based on projectile-barrel-fuse coupling.The results indicated that the buffer cannot reduce the maximal stress to below the bearing steel s yield strength.However,the bearings maximal stress can be reduced to below the bearing steel s yield strength.Through determination of thrust bearing s deformation,this scheme can meet the needs of resisting overloads in the design of the rotating rack,and ensure normal operating of the micro-machine s power generation after launch process.