您好,欢迎来到筏尚旅游网。
搜索
您的当前位置:首页Optimization and experimental research on a new-type short cylindrical cup-shaped harmonic reduc

Optimization and experimental research on a new-type short cylindrical cup-shaped harmonic reduc

来源:筏尚旅游网
J.Cent.South Univ.(2012)19:1869—1882 DoI:10.1007/sl1771—012—1221—0 垒Springer Optimization and experimental research on a new--type short cylindrical cup--shaped harmonic reducer GAO Hai.bo(高海波),ZHUANG Hong—chao(庄红超),LI Zhi—gang(李志刚), DENG Zong-quan(邓宗全),DING Liang(q-亮),LIU Zben( ̄振) State Key Laboratory of Robotics and System(Harbin Institute of Technology),Harbin 1 5000 1,China ◎Central South University Press and Springer-Verlag Berlin Heidelberg 2012 Abstract:In order to obtain a new.type short cylindrical cup.shaped flexspline that can be applied to space mechanisms.the APDL language of ANSYS software was employed to develop a parameterized equivalent contact model between a flexspline and a wave generator.The validity of the parameterized equivalent contact model was veriied by comparfing the results of the analytic value of the contact model and the value calculated by the theoretical formula.The curvilinear trend of stress was obtained by changing the structural parameter of the flexspline.Based on the curvilinear trend of stress.multi.objective optimizations of key structaral parameters were achieved.Flexspline.wave generator,and circular spline of a new 32.type short cylindrical cup.shaped harmonic reducer were designed and manufactured.A performance test bench to carry out tests on the harmonic reducer was designed.Contrast experiments were implemented to determine the emciency of the new 32.type short cylindrica1 cup—shaped harmonic reducer and he tconventional 32.tvDe harmonic reducer under different conditions.The experimental results reveal that there is approximately equaliy in tterms of emciency between he new t32.type short cylindrical cup.shaped harmonic reducer and the conventional 32一type harmonic reducer.The volume of the flexspline of he new 32 ttype short cylindrical cup.shaped harmonic reducer is reduced by approximately 30%through multi.obiective optimization.When het new 32.type short cylindrical cup.shaped harmonic reducer is used on the wheel ofa rover prototype,the mass ofthe wheel hub is decreased by 0.42 k旦.TE st analysis ofwheel motion verifies that the new 32.type short cylindrical cup—shaped harmonic reducer can meet the requirements regarding bearing capaciy and te衔ciency. Key words:harmonic ridve;flexspline;structural parameter;multi—objective optimization great deal of research on harmonic reducers.Their 1 IntrOductiOn The harmonic drive『1-4]has several characteristics. It features a high—speed reduction ratio with near zero research efforts have encompassed the principle of engagement,new gear form,flexspline fatigue strength, 仃ansmission accuracy,etc r16-171. Although the harmonic drive has captured an increasing amount of research arention and has been widely applied over the last few decades,some problems related to drive technology remain that need to be backlash[5],excellent positioning accuracy and repeatability[6],low weight[7],compactness[8—9], high carrying capaciy,hitgh smoothness,multiple teeth contact and multizone gearing[10].Because of the various significant advantages of he harmonitc drive,it has been used in a wide range of precision products,such resolved.Massive experimental data are required, especially on the research of flexspline.Generally, theoretical formulas are chosen to design harmonic as indus仃ial robots,machine tools,medical facilities f111, ridving pa_ns of measurement systems,semiconductor reducers.Based on meeting the life span and efnciency requirements of harmonic reducers,a cup—shaped lexspline has been desifgned.However,the axial size of he cup—shaped ftlexspline is very large.The ratio of the axle to the diameter is approximately 1.0.Therefore.a large axial dimension in a cup・shaped flexspline is disadvantageous for a harmonic drive in a space mechanism. In order to obtain a new type short cylindrical manufacturing systems[12],and space exploration equipment[13—14].As can be seen in Fig.1,the harmonic reducer is composed of three components:A wave generator,flexspline,and circular spline[1 2]. The harmonic drive is a new.ype dtrive that depends on elastic deformation to achieve the goa1 of 仃ansmission『1 51.Some researchers have conducted a Foundation item:Project(2010DFR70270)supposed by the Intemational Science and Technology Cooperation Project with Russia;Pr ̄ects(50975059. 61OO5O8O)supposed by the National Natura1 Science Foundation of China;Project(B070l81 supported by“ll l,’Program of China; Pr0ject(SKLRS200801A02)supported by the Foundation of State Key Laboratory of Robotics r皿a System(Harbin Institute of Technology),China;Project(HIT2009061)supported by the Key Subiect Laboratory Open Fund ofChina Received date:20l1-07-26;Acceoted date:2011-11-14 C0rresp0nding anthor:GA0 Hai—bo,Professor,PhD;Tel:+86-451-86413857;E—mail:gaohaibo@hit.edu.cn,zhuangchaol026(国sina.tom 1870 Wave generator Flexspline Circular spline Fig.1 Components ofharmonic drive[12】 cup—shaped flexspline that can be used in space mechanisms,multi.objective optimizations of the key structure parameters of the cup—shaped flexspline were carried out,based on stress sensitivity analysis of the cup.shaped flexspline in this work.On the basis of the multi-objective optimization results,a new—type short cylindrical cup—shaped harmonic reducer was designed and manufactured.Finally.e衔ciency experiments were implemented on a performance test bench.The new.type short cylindrical cup—shaped harmonic reducers were used on the wheel of a lunar rover prototype and tested on the wheel motion. 2 Influence of structural parameterized variation of lfexspline on stress 2.1 Establishment and verification of parameterized equivalent contact model When the finite element technique『1 8—201 is used to actualize the finite element contact analy sis to different types of flexsplines and wave generators and the infuence analysis coming from the changing of key structural parameters of a single flexspline to its maximum equivalent stress.a large number of iterations are required for calculation.Large.scale labor services are also needed for defining element type,meshing, imposing constrains and loads.and solution with building a new model every time.Therefore,it is greatly necessary to establish a parameterized equivalent contact model to automatically mesh and analyze for flexsplines and wave generators. A large amount of work is also required to mesh and analyze a contact model with gear teeth[2 1].As such, the wall thickness of gear teeth of a flexspline needs to be handled equivalently.Through this equivalent processing,the wall thickness of the gear ring is 1.1 86 4 times the thickness of a smooth ring at the tooth root. The flexspline is a symmetrical structure and bears symmetrical static loads.A quarter model of a flexspline can be established as a substiutte for the entire mode1 of the flexspline in analysis.Time can be saved on calculation and analysis in this manner f22—23]. J.Cent.South Univ.r2012)19:1869—1882 The bottom.uD modelling method was used to build a finite element mode1.The model was established from low—level primitive to high-level primitive.Namely,the line was created by points.The area was created by lines. The volume was created by areas.The bottom.uD modeling method is easy to realize parametrization to one—quarter of the flexspline and wave generator.APDL language of hte ANSYS software was chosen to compile the parameterized programs. Based on the basic parameters researched,the three.dimensional model of a flexspline and wave generator with nonequivalent handling,which has gear teeth and the same parameters as the conventional 32.type harmonic reducer,was established by the Pro/E software.Meanwhile.the three.dimensional model was imported into the software of ANSYS.The operating methOd of the ANSYS software was progressively to define element type and material properties,mesh,create constrain loads and a couple of contacts(as shown in Fig.2),and solve the mode1.Nephograms of the equivalent stress and displacement were obtained,as shown inFig.3. Fig.2 Scheme of contact model of flexspline and wave generator When the inDut operation of parameters was actualized trhough a program interface(as shown in Fig. 4),the 3-D equivalent contact model,meshing, equivalent stress,and displacement of a flexspline and wave generator of conventional 32.ytpe harmonic reducer were respectively obtained.as shown in Fig.5. According to the analysis results from the model of the gear tooth,Fig.3 shows that the maximum displacement of the flexspline with nonequivalent handling is 0.233 666 1Tlrn。and the maximum equivalent stress of the flexspline with nonequivalent handling is 3 19.241 MPa.Based on the analysis result of the parameterized equivalent contact model,Fig.5 shows that the maximum displacement of the equivalent contact mode1 of the flexspline is 0.252 727 rnlr1.and the maximum equivalent stress of the equivalent contact 1872 model of the flexspline is 325.200 MPa.By comparing the analysis results between the nonequivalent handled contact model and the equivalent contact mode1.it is concluded that the relative error of the maximum displacement is 0.0 l 9 09 1 nln1.and the relative error of the maximum equivalent stress is 5.959 MPa.The nephograms of the srtess and displacement of the equivalent contact model are similar to those of the nonequivalently handled contact mode1.Comparing the conventional flexspline and wave generator thus verifies that the parameterized equivalent contact model of the lfexspline and wave generator is accurate. Based on the third strength theory and ANSYS software,the maximum equivalent stresses of flexsplines of conventional 25-60 type harmonic reducers were respectively obtained by the theoretical formulas[24] and the finite element technique.A fitting curve of the maximum equivalent stress was gained,as depicted in Fig.6. Inner diameter of lfexspline/mm Fig.6 Maximum equivalent stress curves of flexspline of conventional 25-60 type harmonic reducer Figure 6 shows that the maximum equivalent stress of flexspline of conventional 32一type harmonic reducer is 277.5 12 MPa by calculating on the theoretic formulas. and it is smaller than the maximum equivalent stress of lfexspline by analysis of ANSYS software.The main reason can be illustrated that the theoretical formulas were simplified and actualized types of hypothesis. Meanwhile,to revise correction factors of hte theoretical formula is another important reason. Figure 6 also shows that the maximum equivalent stress of flexspline gradually decreases with the augmentation of type of flexspline.In other words,the lower type harmonic reducer has shorter 1ifespan. 2.2 Influence of flexspfine stress caused by structural parameterized variation In order to actualize the optimized design to the geometric parameters of hte flexspline,it is necessary to examine how the structural parameter of the flexspline J.Cent.South Univ.(2012)19:1869—1882 affects the working performance.A flexspline is composed of smooth cylinder and tooth ring whose widt∞ 、h is b.The wall∈曲∞耋∞ I10一对>一j叮o— thickness of fIIt1—II—xB州 lexspline contains the wall thickness of tooth ring and the wall thickness of the smooth cylinder.The smooth cylinder includes the front-end flange whose width is c and the back.end boss, as showninFig.7. Fig.7 Structural model of lfexspline and wave generator According to the structural characteristic of the lfexspline and the numerical range of parameters.the main structural parameters were chosen.They mainly included the length of the cylinder of flexspline(J『),the wall thickness of hte tooth ring 1),the wall thickness of the smooth cylinder( ),the tooth width(6),and the round radii ofthe lfexspline 1,RE,and R3). 2.2.1 Influence of length of cylinder of lfexspline, The 1ength of the cylinder is one of the most important structural parameters for the flexspline.The influence of the 1ength of the cylinder is very strong for hte stress of the flexspline.The length range of the cylinder was set from 11 tO 35 mm.When only the length of the cylinder was changed,a fitting curve was obtained。as depicted in Fig.8. Figure 8 illus仃ates that the maximum equivalent stress of the flexspline gradually decreases with length Length of smooth cylindrical/mm Fig.8 Influence of length of cylinder on maximum equivalent s仃ess J.Cent.South Univ.(20121 19:1869-1882 augmentation of the flexspline.When the length of the cylinder of the flexspline is fixed as 1 1-20 rnnl,that is, the length to diameter ratio of the flexspline is from 0.35 to 0.60.the maximum equivalent stress rate decreases. Ⅵ en the length of the cylinder of the flexspline is 20-25 1Tllrl,that is,the length to diameter ratio of the lfexspline is from 0.60 tO 0.80.the curvilinear trend of the maximum equivalent stress exhibits a slow drop. When the length of the cylinder of the flexspline 1ies in 1 1-20 113111 range.that is。the length to diameter ratio of the flexspline is greater than 0.80.the maximum equivalent stress remains approximately constant.As such。according to Fig.8,it can be conclu【ded that the maximum stress of the smooth cylinder and the gear ring has a similar trend. 2_2.2 Influence ofwall thickness oftooth ring The wall thickness of the tooth ring was set from 0.25 to 0.7O inin.When only the wall thickness of the tooth ring was changed,a fitting curve was obtained,as depicted in Fig.9.Bd ∈∞∞占∞甚0一  一; 0 IIIj暑誉 Wall thickness of gear ring/mm Fig.9 Influence of wall thickness of gear ring on maximum equivalent stress Figure 9 illustrates that the maximum equivalent stress of the flexspline is from decline to augmentation with the increase of wall thickness of the flexspline.The decline region of the maximum equivalent stress of lfexspline is from 0.25 tO 0.40 nnn:the augmentation region of the maximum equivalent stress of flexspline is rfom 0.40 to 0.70 lnn1.The maximum equivalent stress of the smooth cylinder of hte flexspline increases in an approximately linear manner with the increase of wall thickness of the tooth ring of lfexspline. 2.2.3 Influence of wall thickness of smooth cylinder The wall thickness of the smooth cylinder was set rfom 0.10 to 0.40 Inff1.When only the wall thickness of the smooth cylinder was changed,a fitting curve was obtained.as depicted in Fig.1 0. Figure 1 0 illustrates that the maximum equivalent stress of the flexspline is from decline to augmentation with the increase of wall thickness of smooth cylinder. 1873 ∈∞∞ 扫∞=lIIo一时 一tl叮0 IIIt1【_Il一 Wall thickness of smooth cylinder/mm Fig.10 Influence of wall thickness of smooth cylinder on maximum equivalent sffess The curve of the maximum equivalent stress of the lfexspline is not smooth.The maximum equivalent stress of the smooth cylinder graduallBd苫,ss皇s1y decreases and iII _【EAIng gj吕一ts curve 蓉苫 is very smooth. 2.2.4 Influence of tooth width b The tooth width was set from 5 to l1 rnlT1.When only the tooth width was changed,the fiting curve was obtained.as depicted in Fig.11. Tooth width/mm Fig.11 Influence oftooth width on maximum equivalent stress Figure l1 illustrates that the maximum equivalent stress of the flexspline is from decline to augmentation with the increase of tooth width.The maximum equivalent stress of the smooth cylinder gradually decreases with the tooth width from 5 to 1 0 min. However,the curve of hte maximum equivalent stress of the smooth cylinder keeps approximately a level,ranging rfom 10 to ll i/lln.The reason forthis canbe illustrated as follows.When the tooth width increases,it is equivalent to reduce the length of the smooth cylinder. Namely.the rigidity of the smooth cylinder increases. Hence。the maximum equivalent stress of the smooth cylinder gradually decreases with the augmentation of tooth width. 1874 2.2.5 Influence ofround radius R1,R2 and R3 The round radii R1,RE,and R3 were respectively defined as 0.25—2.5 mm,0.15—3 n】善∞∞o虹∞ IIm,and o一对 一 0 0.15—2.I_Il等—II一 ∞ 5 Inm. When respectively changing only the round radius RI,R2, and R3,the fitting curves were obtained,as depicted in Figs.12,13 and 14. 330 3l0 290 270 250 Round radius,RI/mm Fig.12 Influence of round radius RI on maximum equivalent sffess Round radius,R2/mm Fig.13 Influence of round radius RE on maximum equivalent stress Round radius,R3/mm Fig.14 Influence of round radius R3 on maximum equivalent s仃ess J.Cent.South Univ.(2012)19:1869—1882 According to the results of the fitting curves of stress at different values of R】,R2,and R3,it can be deductedthatt日 W/ss ∞ aIhe values ofR】,R2,and ≈AI III 暑一苍一R3  cause the small influence on the maximum equivalent stress of the flexspline.When only R1 was changed,the curvilinear rtend of the maximum equivalent stress of the flexspline was from augmentation to decline.When only R,was changed.the curvilinear仃end of the maximum equivalent stress of the flexspline exhibited a gradual increase.When R1 was greater than 0.25 inln.the curvilinear trend of hte maximum equivalent stress of hte lfexspline basically remained unchanged. Similar results can be obtained for the 25-60 type harmonic reducer in accordance with the process mentioned above.Therefore, based on structural parameters of flexspline of conventional 32一type harmonic reducer,it is concluded that the influence on the maximum equivalent stress of the flexspline and the smooth cylinder is mainly derived from the length of the cylinder,,the wall thickness of the tooth ring 1,the wall thickness of the smooth cylinder .and the tooth width b. The variation of hte round radii R1,R2,and R3 have little influence on the maximum equivalent stress of the lfexspline.The 1ength of the cylinder is the main factor that influences the equivalent stress of the flexspline. When the length to diameter ratio of the flexspline exceeds 0.6,the variation of the maximum equivalent stress of the lfexspline is very little. The curvilinear trends of the maximum equivalent of stress,which are respectively caused by the variation of the wall thickness of the tooth ring and the wall thickness ofthe smooth cylinder,do not conformto the principle of monotonicity,and they are from decline to augmentation 纬西en changing only the tooth width of the flexspline.the curvilinear仃ends are adverse between the maximum equivalent stress of the flexspline and the maximum equivalent stress of the smooth cylinder. 3 Multi-objective optimizations of short cylindrical cup—shaped flexspline 3.1 Mathematical model of multi-objeetive optimizations 3.1.1 Definition of design variables According to the analysis of the main structura1 parameters of flexspline,design variables are defined. They are the modulus of the flexspline ),the length of the cylinder(D,the wall thickness of the tooth ring( 1), the wall thickness of the smooth cylinder ),and the tooth width( .Thus,the variable function is written as follows: X= , ,b,,, 】T= , , , , 】T 3.1.2 Establishment of objective functions BdJ.Cent.South Univ.(2012)19:1869—1882 Under the condition of ensuring high fatigue life and carrying capacity equivalent of the conventional flexspline,the volume of the flexspline(r3 and transmission efifciency(叩)are respectively viewed as objective function ∞and for multi-objective optimization. The volume of hte flexspline contains two pa ̄s:the gear ring and the smooth cylinder.The volume of the lfexspline can be expressed as =7r{[ +d+(2ha+c ) 】[ +(2 +c ) ]6+ ndm6(t一6)) (2) Then A(x)=兀( +x2+2.35x ̄)(x2+2.35x1)x3+ /Uf1(gI一2.7+2x1一X2)x5(x4一X3) (3) l where dr is the bore size of the flexspline, is the addendum coefifcient,c is the tip clearance coefifcient, nad is the neutral circle diameter of the flexspline under nondeformation. Transmission efifciency叩is written as[25] ’ (4) where r/e=7 日 (1-i[n2 )/( H)一《 ),and叩。is mesh efifciency; is the efifciency of the wave generator, which includes g1 and qg2; is the transmission ratio under the fixing wave generator;t/gl is the efifciency of the wave generator bearing strain forces;t/g2 is the efifciency of the wave generator bearing an engaging force.Their equations are 77g1 1一 ( ) lm 2r/e i(2)H1+ 1(1一 1)(tan + ) 叩g2 1+ 2G l ̄21 (tana+ ) where r/(H)is the efficiency of the transforming mechanism. is the correlation coefficient of the size distribution of the flexible bearing under the multi.1oad, is the correlation coefifcient of the rolling element distribution under the multi.1oad,Pr1 is the radial load on the flexspline bearing,Tm is the input torque,f is the transmission ratio under the fixing circular spline.。【is the tooth profile angle, is the friction factor,7,2 is the number of teeth of the circular spline,and/'2 is the reference radius of the circular spline. Therefore.the objective function of emciency is 厂2( )=rl ,7e叩glrlg2 ( ,x2,x4) (5) l875 3.1_3 constraint conditions 1、Constraint condition of fatigue strength A method that checks the safety factor under two・・directional stable・・changed stress is chosen to calculate the fatigue strength. is the safety facto ̄Thus, n nf ,2= -l ≥/,/p (6) where is the demand safety factor, :is the parameter under the influence of axial stress ,n is the safety factor under the condition of normal stress盯.and n is the safety factor under the condition of shear stress 2、Cons仃aint condition of carrying capacity The output torque ofthe flexspline is defined as To. The carrying capacity is regarded as TI.The condition is 一r0≥0 功us. rl cbd1hnz pt 一cbmhnz1 Pp 8 000 K (7) where s is the ratio of the total number of teeth in engagement,dl is the reference diameter of the flexspline, is the maximum engaging—in depth,K is the loading coefifcient,andpp is the allowable speciifc pressure[26]. 3、Constraint condition of wall thickness of gear ring Based on the requirement,the wall thickness of the gear ring is ≥ . (8) where d2 is the reference diameter of the circular spline. is the coemcient of the number of working teeth,E is the material modulus of the elasticity of the flexspline, and is the nonunifo1"111 coefifcient of load distribution under the tooth space of running wheels.KF meets the requirement of the equation,namely,KF=(0.136 6zl— Kw) . is the coefifcient of deformation[27]. 4、Constraint condition of bending strength The bending strength of the lfexspline should satisfy the constraint condition.Thus 6E crF (9) Zv F rFV is the allowable bending stress of the lfexspline,and Zy is the equivalent number of teeth. 5)Constraint condition ofnoinstabiliyt The consrtaint condition ofnoinstabiliyt is : 8+ …。 where t1876 J.Cent.South Univ.(2012)19:1869—1882 reducer is reduced by approximately 30%through ≥(1.5~2)vT where 1,is the Poisson ratio of material,rm is heneutralt circle diameter,and rT is the shear torque caused by multi—objective optimization.The length of the cylinder of the flexspline becomes shorter than the front of the optimization.and the wal1 thickness of the flexspline becomes thinner than that of pre.optimization.The goal torsional moment of the extemal load[27]. 6、Constraint condition of wall thickness for smooth cylinder of the multi.obiective optimization is realized under the precondition of satisfying the fatigue life and output torque for the conventional 32一type harmonic reducer. The wall thickness of the smooth cylinder should meet the constraint condition.Thus, 吉 】 …) 4 Experimental research on short cylindrical cup—shaped harmonic reducer where is the torsional section modulus. 7、 Cons仃aint condition of optimized design variables The modulus of hte lfexspline f 1 is a discrete value The common useful value of the modulus contains 0.1. 0.15,0-2,O.25,0-3,0.4,0.5,0.6,0.8 and 1.0.The wall thickness ofthe tooth ring f61)is constrained from 0.01dl to 0.03d1.The tooth width of the flexspline(6)should meet the constrain conditions,which is 0.1d】 6 0.3d1. The length of the cylinder(I『)is 0.5d1<『<1.2d1.The wall thickness of the smooth cylinder( )should satisfy 0.6 1三 三10.9 】. 3.2 Optimization example and results analysis According to the characteristic of the mathematic model established above.the mathematic model is attributed to a nonlinear programming problem.As such, it can be solved by the multi—objective optimization function of fgnalattain in the MATLAB software. The flexspline of the conventional 32-type harmonic reducer was optimized.A double.wave drive and cam wave generator were chosen for the harmonic drive.The value of the transmission ratio ff1 was 80. 40C NiMpA material was selected for the flexspline.The rated output torque was greater than or equal to 5.5 N’m. The input speed was required.and its value was not smaller than 1000 ffmin 功e input power was set at 1 2 W The profile angle was 20。.According to the optimized model of the flexspline of the conventional 32.type harmonic reducer mentioned above,the correlation data of structural parameters between the front of the optimization and the end was obtained,as presented in Table 1. Table 1 Correlation data of structural parameters of flexspline pre—・and post—・optimization Table 1 reveals that the volume of the flexspline of the new 32・-ytpe short cylindrical cup--shaped harmonic 4.1 Establishment of experimental sample 7en the main structure parameters were determined,finite element analysis was carried out on the structures of three types of short cylindrical cup—shaped flexspline.Three types of bosses for short cylindrical cup—shaped flexsplines are shown in Fig.1 5. Figure l 5fa1 shows that the entire boss is 1ocated at the itnernal flexspline.Figure 15(b)shows that half of the boss lies in the intemal flexspline.and the other half of the boss is located in the external lfexspline.Figure 1 5(c) shows that the entire boss is situated in the external lfexspline. ANSYS software was respectively employed to analyze the three types of bosses of the flexspline. 场en the entire boss is located at the internal flexspline,the equivalent stress and displacement of flexspline are obtained.as shown in Fig.16.When the boss is uniformly dis仃ibuled in the interna1.and—extemal lfexspline,the equivalent stress and displacement of lfexspline are obtained as shown in Fig 1 7.纷西即the entire boss is situated in the extemal flexspline.the equivalent stress and displacement of flexspline are obtained.as shown in Fig.1 8. According to the analysis result by the ANSYS software,the maximum equivalent s ̄esses of the three types of short cylindrical cup—shaped flexsplines are approximately equal under the same load,whereas the maximum displacements of the three types of short cylindrical cup—shaped flexsplines are to some extent different.Through a respective comparison of analysis data of rigidiyt and intensiyt between the three types of short cylindrical cup—shaped flexsplines, it is demonstrated that the structure of the boss which is uniformly distributed in the intema1.and.extemal lfexspline(as shown in Fig.1 5(b))is the most reasonable. Based on the multi.objective optimizations of the key structural parameters for flexspline,the most reasonable structure of the boss for the short cylindrical cup—shaped flexspline.and the most reasonable size of wave generator and circular spline by referring the theoretical formula 曲e experimental sample of坊e new J.Cent.South Univ.(2012)19:1869—1882 cylindrical cup—shaped harmonic reducer and the conventional 32.type harmonic reducer.The value of the temperature rise is approximately 7。C.This verifies that the new 32—-type short cylindrical cup--shaped harmonic reducer satisfies the demand of slow temperature rise. 4-3.2 Test on ef氍ciency 1 1 Comparative analysis of efifciency under same load nad rated speed of elec仃ic motor The input torque and output torque of the new 32・・type short cylindrical cup--shaped harmonic reducer and the conventional 32一type harmonic reducer were respectively obtained under the same load and rated speed of electric motor.The curves of the torque were also determined,as respectively shown in Figs.2 1 and 22.As such.the curves of efhciency were obtained between the new 32..type short cylindrical cup..shaped harmonic reducer and the conventional 32.type harmonic reducer,as depicted in Fig.23. Time/s Fig.21 Curves of torque for new 32一type short cylindrical cup-shaped harmonic reducer g j 0 Fig.22 Curves of torque for conventional 32一type harmonic reducer According to Figs.2 1 and 22,the curves of the output torque basically kept unchanged for the new 32・-type short cylindrical cup・-shaped harmonic reducer and the conventional 32-ytpe harmonic reducer.The value ofthe output torque is from 4.95 to 5.15 N’m.and l879 (-吕.ZJ/0jbJ0 1.1 l・0 分0.9 量 毒0.8 O・7 O・6 0.5 0 20 40 60 80 l00 l20 Time/s Fig.23 Curves of efifciency between new 32-type short cylindrical cup-shaped harmonic reducer and conventional 32一type harmonic reducer under same load and rated speed of electric motor the value of input torque ranges from 0.07 to 0.085 N・m. Figure 23 reveals that the curve of efifciency of the new 32--ytpe short cylindrical cup--shaped harmonic reducer displays much less fluctuation than that of the conventional 32一type harmonic reducer,and the average value of efifciency of the new 32一type short cylindrical cup—shaped harmonic reducer is 70%-80%. 2、Comparative analysis of efifciency under same speed When the input speed was 2l8 r/min.the compar ̄ive experiment was actualized between the new 32一type short cylindrical cup—shaped harmonic reducer and the conventional 32.type harmonic reducer at different output torques.The experimental result is shown in Fig.24. >、 0 a . U 甚 ∞ Fig.24 Efifciency of new 32一type short cylindrical cup—shaped harmonic reducer and conventional 32-type harmonic reducer atdifferent outputtorques Figure 24 shows that the efifciency ofthe two types of harmonic reducers increases with the augmentation of output torque.The efifciency rapidly increases from 1882 system[c]//2010 Sixth International Conference on Natural Computation(ICNC 2010).Yantai,China:IEEE Computer Society, 2010:4278-428 1 [10] CHEN Xiao・xia,LIN Shu—zhong,X1NG Jing—zhong.The investigation of elongation of the neutral line in harmonic drive【C]II 2010 International Conference on Computer Design and Applications (ICCDA 2010).Qinhuangdao,China:IEEE Computer Society,2010: 383-386. GAO W瓯FURUKAWA M,KIYONO S, AZAl(I H.Cutting error measurement of flexspline gears of harmonic speed reducers using laser probes[J].Precision Engineering,2004,28(3):358—363. 【12] JEON H S.OH S H.A study on stress and vibration analysis of a steel and hybrid flexsplnie for harmonic drive[J].Composite Structures,1999,47(1/2/3/4):827—833. 【13] GAO Hal—bo,LI Zhi-gang,DENG Zong quan.Sensitivity analysis of cup—shaped lfexible gear parameters to its stress based on ANSYS[J】l Journal ofMechanical Engineering,2010,46(5):卜7(in Chinese) [14] BAUMGAI NER E BONITZ R G SHIRAISHI L R,MELKO J P’ LEGER P C.The mars exploration rover instrument positioning system[c]//2005 IEEE Aerospace Conference.Big Sky,Montana: Instiutte of Electrical and Electronics Engineers Computer Society, 2005:1-19. [15] ZHOU Hui,WEN Qing—ping,ZHANG Wei—wen.Harmonic drive used in spacecraft[J]Vacuum&Cryogenics,2004,10【4):187—192. (in Chinese) [16】 XIN Hong-bing,XIE Jin—mi,HE Hui-yang,ZHANG Zuo-mei. Harmonic drive technology and its research tendency[J].Journal of Beijing Instiutte ofLight Industry,1999,17(1):30—36.(in Chinese) [17] MAO Bin.bin.WANG Ke—wu.Research and development outlined of tooth profile of harmonic gear[J].Coal Mine Machinery,2008, 29(7):6—8.(in Chinese) [18] ifN Jun song,XIA Ju-chen,WANG Xin—yun,Hu Guo—an,Liu Hua. J.Cent.South Univ.(2012)19:1869—1882 Die design for cold precision forging of bevel gear based on finite element method fJ].Joumal of Central South University of Technology,2009,16(4):546—551. [19】 ZHUANG Hong chao,WANG Jin-dong,WANG Ning,SHI Rang,LI Yan.Mechanica1 characteristic analysis of the magnetometer sturcture component for the space exploration[J】l Chin J Space Sci, 201l,3l(1):l12—117.(inChinese) [2O] OSTAPSKI W.MUKHA I.Stress state analysis of harmonic drive elements by FEM[J]_Bulletin of the Polish Academy of Science, Technical Science,2007,55(1):1 15—123. [21] HE Jing—liang,WU Xu—tang,CUI Ya-hui,NIE Gang Tooth contact naalysis of conical involute gears『j].Chinese Joumal of Mechanical Engineering,2006,l9(1):105—108. [22】 XIN Hong-bing.Finite element analysis of stress on tooth rim of a lfexspline[J].Mechanical Science and Technology,2003,22(4): 558—559.(in Chinese) [23] KAYABASI O,ERZINCANLI F.Shape optimization oftooth profile of a flexspline for a harmonic drive by finite element modeling[J]. Materials&Design,2007,28(21:441-447. [24] Gear Manual Edit Commitee.Gear manual[M].Beijing:China Machine Press,2005:9-12—9—13.(in Chinese) [25】 SHEN Ytm—wen.YE Qing-tai.The theory nad design ofthe harmonic gear drive[M].Beijing:China Machine Press,1985:2-235.(in Chinese) 【26】 RAO Zhen—gang.The design of plnaetary transmission mechanism 【M]Beijing:National Defense Industrial Press,1994:547—581.【in Chinese) [271 YAN Yan—hong.Optimization design on structural dimensions of plastic harmonic gear rdive[J]. Mechanical Design,2002(10):38—40 (in Chinese) (Edited by YANG Bin【 

因篇幅问题不能全部显示,请点此查看更多更全内容

Copyright © 2019- efsc.cn 版权所有 赣ICP备2024042792号-1

违法及侵权请联系:TEL:199 1889 7713 E-MAIL:2724546146@qq.com

本站由北京市万商天勤律师事务所王兴未律师提供法律服务