Improved Research On Tubular Linear Oscillating Motor

TLOM(Tubular Linear Oscillating Motor),due to its axisymmetric structure,has lower bearing wear and more robust.Generally considering,the tubular core is possible to embrace the ring coil entirely and almost eliminates the end of the winding,thus the magnetic material utilization and power density performance are improved.TLOM would help VEC(Vibration Electric-energy Converter)with EMS(Electromagnetic Suspension)function,is the core component of high efficient VEC system.The performance of TLOMVEC is restricted by the TLOM.The EST(Eddy Suspension Technology)for TLOM is not mature enough and prevent high speed realization of TLOM and VEC.EST is key problem of TLOM now and worth putting more effort in.From the electromagnetic theory and circuit model of tubular linear oscillating motor,model based on non-periodic inductance is deduced.Expressions of induced voltage,thrust force,power are obtained.The result indicates that under linear assumption for surface mounted permernant magnetic single phase motor,the interchanging mechanic-electric power is equal to power of moving induced voltage,as well as power of current thrust.Power of inductance voltage only oscillating in circuit while power of magnetic reluctance only oscillating in mover equations.Linear oscillating equations for VEC is analyzed.The single oscillation and double oscillation are compared.From case study,the max converting power of double oscillation system is 1.5 times of single oscillating system and the response perodic band width is 1.9 times,proving that the double oscillating system performed better in wider response frequency band.The choice of phase number,magnet number of secondary part,winding distribution and bearing type is importance during the process of motor design.Different arrangements of secondary magnets are compared.The results proved that the existence of half pole at the end of magnet array can improve the utilization ratio of magnets and lengthen the stroke.Three bearing types for tubular oscillating motor are summarized and compared.The inset multi-layer flux concentrated structure of secondary part is proposed to enhance the hardiness of long stroke motor and decrease the volume of motor.3L-HL(3-Layer Hybrid Lamination)combined the merits of AL(Axially Lamination)and CL(Circular Lamination),is proposed as a good candidate for EST of TLOM.The geometry model of 3L-HL is analysed.As an important component part of 3L-HL,expressions of CL are deduced including lamination effectiveness,inner and outer additional gap,winding embracing index,ending index and lamination volume index.Case study showed that compared to traditional CL,the 3L-HL incease outer embrace coefficient is 65% and volume coefficient is 35%.Flux density analysis showed that the flux distribution of 3L-HL has a best analog of NL.Simulation shows that under 50 Hz the core eddy loss of 3L-HL is only 0.5% of NL,and core loss is less than 21.3%.The equivalent resistance separation model is deduced from loss separation model.Prototype of single phase permanent TLOM is designed and maked.Tested with resistance is 0.92 Ω,inductance is 3.5 mH,induced voltage coefficient is 9.8 Vs/m,current force ratio is 9.7 N/A,max reluctance force is 10.9 N,frictional force is 5.4 N.Experiments test for TLOM were carried out under generating and motoring states,respectively.The no-load and load operation,cogging force and blocking operation are performed.Motor parameters are extracted based on motor model and harmonic analysis method.External characteristics of generator,impedance value,cogging force curve,thrust force by current are obtained.Experiments also performed for coils with different iron core.The eddy effect is evaluated.The 50 Hz test result show that the core loss of 3L-HL is only 16.4% of NL which is according to the design and analysis,and the 3L-HL is effective for suppress the eddy of TLOM.