翻译原文-基于UG的减速器三维实体模型和运动仿真.pdf

内蒙古工业大学学报 JOURNAL OF INNER MONGOLIA 第 22 卷 第 2 期 POL YT ECHNIC UNIVERSIT Y Vol. 22 No. 2 2003 c I | : 1001- 5167( 2003) 02-0153-04 Inner M ongolia Polytechnic University Departm ent of M echanical Engineering T he 11th Sino-Polish Conference on CAD in M achinery Huhhot, China, Oct ober 2002 ZHANGYe College of Mechanical Engineering, Inner M ongolia Polytechnic University, Huhhot, 010062 T HREE-DIM ENSIONAL ENT IT Y M ODEL AND M OVEM ENT EM ULAT ION OF REDUCER BASED ON U G PL ANE Abstract: This article introduces to m odeling for reducer w ith three- dimensional entity by M OSWLING module in the latest edition U G N X of UG softw are, w hich mainly concern w ith model of the main com ponents such as shaft, gear, gear shaft, mount and cover and com plete cor responding assembly. Then, car ry out movement emula- tion for all the assem bly w ith M OT ION module. Keywords: UG; three-dim ensional entity model; reducer; emulation U G is three-dimensional entity model plane which integrates CAD/ CAM / CAE, and is computer aided design, analysis and manufacture softw are w hich is used w idely in the w orld. There are several pr oblem s should be paid attention to in this article: involutes tooth profile m odel of gear teeth, hol- low ing operation of cover w hen modeling, location betw een gear shaft and gear when assem bling. 1Plottinginvolutestooth profileof gearteeth Involutes tooth profile of gear teeth can be plotted with “expression “ in UGq3r. On the other hand, this ar ticle pr ogram for involutes tooth pr ofile of gear teeth w ith V C+ + 6. 0 and save coordi- nate value of tooth pr ofile surface in corr esponding data file, and plot involutes tooth profile of gear teeth using “read point fr om file“ in spline w ith the defined point. Polar coordinates parameter equation of involutes isq4r r k = r bcosnull k nullk = invnullk = tgnullk - nullk make rk and nullk go to x k= r kccosnullky k = rkcsinnullk and spr ead w ith trigonom etric expressions, can get: xk = rbcqcos( nullk+ nullk) + (nullk + nullk) csin(nullk+ nullk )r yk= rbcqsin(nullk+ nullk) - (nullk+ nullk )ccos(nullk + nullk) r Here rk is radius of involutes tooth profile at K point, nullk is angle of involutes at AK segm ent, r b is base radius and nullk is pressure angle at K point. Fig. 1 Fig. 2 Program w ith VC+ + 6. 0 and change (nullk + nullk ) fr om 0 to 180, can get corresponding xk and yk, and save them in corresponding data file jkx. dat. The results like Fig. 1. Inser tCurveSpline in UG main menu , click “Through Points“ button after show ing dia- logue, then the system show dialogue Spline Through Points like Fig. 2. Click “Points From File“ button and select before-mentioned data file jkx. dat, can get corresponding involutes like Fig. 3. Fig. 3 154 = v 2003 M Because tooth thickness and tooth spacew idth of reference cir cle is equality, the opposite center angle of gear teeth and tooth space is equality, then the opposite center angle of half tooth thickness is 1 2c 360 2 z , viz 90 z , here z is number of teeth. XC axis should be rotated nullk+ 90 z and m ake the above nullk expression go to, cor ner is tgnullk- nullk + 90z . Because of the pressure angle of r efer ence circle of standar d gear is 20, so XC axis should be rotated ( tg20- 203. 1415926/ 180) 3. 1415926180+ 90z . Plot a line at XC axis, and select the line as center of m irror and m ir ror involutes w ith “Existing Line“ in “ M ir ror Through a Line“. T he r adius of the angle betw een tooth profile surface and roof is = c* cm 1- sinnulli , here m is module, nulli is nominal pressure angle, c* is bottom clear ance coefficientq2r. At last, can get three-dimensional entity model of gear w ith tr ipping, cornering and str etching. like Fig. 4. Fig. 4 At the sam e method, can get gear teeth involutes tooth profile of gear shaft. 2Someproblemsshouldbepaidattentiontowhen modelingcover Hollow cover after completing the whole model of cover , can get partial entity and cant get the perfect full entity. Here, we use “Region“ in “Hollow “ and change cover into tw o par ts: bearing seat, pr otuberant level and boarding body w hich is connect w ith mount is one par t, the other is another part, and hollow separately. The key point is the two parts cannot Unite before hollow ing and must be United after hollow ing. We think the complicated body should be disintegrated into simple bodies and be hollowed separ ately, then U nite. 155 2 ZHANG YeThree-Dimensional Entity M odel and M ovement Emulat ionll 3Locationof gearshaftand gearwhenassembling Axial location between gear and gear shaft is not confir med w hen they are assembled on mount, so intervening can happen among gear teeth. T here are eight types r estriction in UGq1r, such as Mate, Align, Angle, Parallel, Perpendicular, Center, Distance and T angent, but they all cannot set up mating relation of tw o gears. T herefore, it is necessar y to plot corresponding location surface during the course of entity m odel of gear shaft and gears. Here w e plot centerline of tooth space of gear shaft and centerline of gear teeth and the two lines should be kept parallel each other during the course of assem bly, so the intervening am ong teeth can be avoided. We keep the above tw o lines separately par- allel w ith fr inge lines of mount w ith Parallel restriction relation, so the tw o lines may be parallel mor e. T hereby, gear teeth cannot intervene during the course of engagem ent. We complete three-dimensional entity model of the m ain components of r educer . Then, w e m ake movem ent emulation for it. Fir st, establish movement analysis case, and gear shaft and bearing inside track is link 1, and shaft, gear, fixed-distance loop and cor responding bearing inside track is link2. Then, set up Joint for movement unit, namely set up Revolute betw een gear shaft and gear separate- ly. At last, set up Compound -Gear of revolute1 and 2. Select Kinematic/ Dynamic Analysis in Ani- mation, and input T ime and Step, w e can make movem ent emulation for reducer . Reference: 1 Guangli Zhang, Peng Zhang, Xue Hong