Better torque performance and higher reliability have long been the focus of research for slotted limited-angle torque motors(LATMs),which are primarily used to position first-stage valves in electrohydraulic servosys...Better torque performance and higher reliability have long been the focus of research for slotted limited-angle torque motors(LATMs),which are primarily used to position first-stage valves in electrohydraulic servosystems.This paper presents a high reliability axial-flux slotted LATM with quasi-Halbach array for torque performance improvement including constant torque range(CTR)and output torque.Firstly,the structure with two sets of windings and the operation principle of the proposed slotted LATM is analyzed.Secondly,a brief design procedure is presented,the structure selections of open slot and double-stator single-rotor(DSSR)interior rotor with surface mounted quasi-Halbach permanent magnet(PM)array are illustrated,and the geometric parameters are optimized to obtain the optimal design of the proposed slotted LATM.Then,3-D finite-element method(FEM)is employed to compare the proposed slotted LATM with the conventional surface mounted PM slotted LATM in terms of cogging torque,no-load back EMF,and output torque,and the results show that the proposed LATM with quasi-Halbach array has a 10%improvement in output torque and a 25%improvement in CTR.Meanwhile,the flux linkages and torque performance of the two sets of windings under various conditions verify good magnetic isolation.Finally,prototypes of two different rotor types are manufactured and a series of experiments are performed to validate the analysis.展开更多
A new artificial boundary condition for time domain analysis of a structure-unlimited-foundation system was proposed.The boundary condition was based on the damping-solvent extraction method.The principle of the dampi...A new artificial boundary condition for time domain analysis of a structure-unlimited-foundation system was proposed.The boundary condition was based on the damping-solvent extraction method.The principle of the damping-solvent extraction method was described.An artificial boundary condition was then established by setting two spring-damper systems and one artificial damping limited region.A test example was developed to verify that the proposed boundary condition and model had high precision.Compared with the damping-solvent extraction method,this boundary condition is easier to be applied to finite element method(FEM)-based numerical calculations.展开更多
基金supported in part by the National Nature Science Foundation of China(NSFC)under Project 52122705。
文摘Better torque performance and higher reliability have long been the focus of research for slotted limited-angle torque motors(LATMs),which are primarily used to position first-stage valves in electrohydraulic servosystems.This paper presents a high reliability axial-flux slotted LATM with quasi-Halbach array for torque performance improvement including constant torque range(CTR)and output torque.Firstly,the structure with two sets of windings and the operation principle of the proposed slotted LATM is analyzed.Secondly,a brief design procedure is presented,the structure selections of open slot and double-stator single-rotor(DSSR)interior rotor with surface mounted quasi-Halbach permanent magnet(PM)array are illustrated,and the geometric parameters are optimized to obtain the optimal design of the proposed slotted LATM.Then,3-D finite-element method(FEM)is employed to compare the proposed slotted LATM with the conventional surface mounted PM slotted LATM in terms of cogging torque,no-load back EMF,and output torque,and the results show that the proposed LATM with quasi-Halbach array has a 10%improvement in output torque and a 25%improvement in CTR.Meanwhile,the flux linkages and torque performance of the two sets of windings under various conditions verify good magnetic isolation.Finally,prototypes of two different rotor types are manufactured and a series of experiments are performed to validate the analysis.
基金This study was supported by Project supported by the National Natural Science Foundation of China(Grant Nos.51109029,51178081,51138001,51009020)the China Postdoctoral Science Foundation(Grant No.20110491535).
文摘A new artificial boundary condition for time domain analysis of a structure-unlimited-foundation system was proposed.The boundary condition was based on the damping-solvent extraction method.The principle of the damping-solvent extraction method was described.An artificial boundary condition was then established by setting two spring-damper systems and one artificial damping limited region.A test example was developed to verify that the proposed boundary condition and model had high precision.Compared with the damping-solvent extraction method,this boundary condition is easier to be applied to finite element method(FEM)-based numerical calculations.
