1、 第 1 页 共 23 页 中文 3330 字， 2170 单词 ,10100 英文字符 EFFICIENCY ANALYSIS OF DOUBLE CRANK RING-PLATE-TYPE PIN-CYCLOIDAL GEAR PLANETARY DRIVE LiXin Department of Mechanical Engineering， University of Maryland Maryland U SA He Weidong Department of Mechanical Engineering， Dalian Railway Institute， Dalian 11602
2、8 China Linda SchmidI Department of Mechanical Engineenng， University of Maryland， Maryland， U S .A Li Lixing Department of Mechanical Engineedng Dalian Railway tnstitute， Dalian 116028 China Abstract： From the general formula for calculating the efficiency ofplanatary gear trains， the efficiency of
3、t the double crank ring-plate-type pin-eycloidal gear planetary driveis derived To prove the theory,all experimental study has been conducted Thetested value ofthe efficiency of a sample set of the new type drive in the experiment agrees with the calculated one It shows that the new type drive is of
4、 not merely high beating capaeity,but also quite high efficiency. Key words： Double crank ring plate type Pin cycloidal gear planetary drive Mesh efficiency. 0 INTRODUCTl0N It iS known that the traditional cycloidal pin wbeel planetary drive of K-H V type which is of multi-tooth mesh and has hardene
5、d tooth flank of gears has a series of essenfial advantages such as small volume,1ight weight wide range of transmission ratio， high efficiency， and utliformo perating aswell .On the other hand， the pin-cycloidal K-H-V type planetary drive has a nataral weak point that the arm bearing， 第 2 页 共 23 页
6、which supports the cycloidal gear on the arm is placed insidetbe cycloidal gear,thereforethe size of the bearing is restrieted due to the geometry of the gear Because of the fact,the bearing capacity of the whole drive can not be developed well eooogh To overcome the shortcoming ofthe traditional cy
7、cloidel-pin wheeI planetary gear train,we developed some designs of the double crank ring-plate-type pin cycloidal gear planetary drive The new-type drive keeps all the advantages described above Since the arm bearing iS placed outside the cycloidal gear,the sizeof the bearing IS llO iongar res 埘 ct
8、ed to any extent The bearingcapacity ofthewhole driveiStheleforcmuch enlarged Moreover,tlle drive does not need the special output unit as the traditionalone does， so that the rigidity of the 011tput shaft becomes muchhigher 1t is shown that the concerned drive will surely provideindustries with suc
9、h a Flew kind ofdrives Which are ofsmall vo1-ume， light weight， wide range of ltansmission ratio， high effi cieney,uniform operating， high rigidity of the output shaft，well knit structure and higll bearing capacity Since the structure of the new-type drive is quite differentfrom the ffaditional one
10、， it is necessary for u,s to make sure thathe efficiency ofthe new driveis high Inthispaper,we present a theoretical and experimental study on the efficiency analysis of he new-type drive 1 KINEMATICPIUNCIPLE The kinematic diagram of the double crank ring-plate-type pin-cycloidal gear planetary driv
11、e is shown in Fig 1 The pin gear is mounted On the coupler BC of a four-barparallelogram linkage ABCD The center oft he pin gear is at the middle ofthe coupler And the center of the eycloidal geat,which meshes with the pin gear,is at the middle ofthe fixed Iink AD The center distance (eccentricity)
12、is always equal to the length， of the crank and parallel to them As a motor drives crank 1 to rotate the coupler does a pure translation The point on the coupler,or on the pin gear,moves along a circle ofradius equal to f The center point 0f the pin gear moves along the circle of radius l with its c
13、enter at point Due to the mesh ofthe pin gearwiththe cycloidal gear, the former drives the lattcrto rotate about the fixed axis 第 3 页 共 23 页 Where: -Angular velocity of the driving crank l -Angular velocity of the cycloidal gear or the output shaft -Number of teeth of the cycloidal gear -Number of t
14、he pins For static balance of the mechanism two ring plates with phase difiefence may be used To keep dynamic balance We may use another axially 8ymmeUicaI pair offing-plates Moreover, to ensule that the driven crank of the four-bar parallelogram link age stably passes the dead point， we rise a sync
15、hronous belt drive as shown in Fig 2 or an ordinary gear train of thing gears kine matieally connecting the two cranks shaIts In the case where two motors， which have the same dynamic performance drive the respective cranks as shown in Fig， 3 Of course we don t need any hold-in range mechanisms 2 GENERAL FORMULA FOR CALCULATING EFFICIENCY OF PLANIHIARY GEAR TRAINS Almost all kinds of planetary gearains can be considered in general to be 8 basic mechanism eomisting ofthree members a B and c as shownin Fig 4 We define base
