上游充通大学 SHANGHAI JIAO TONG UNIVERSITY LECTURE 7 CAM DESIGN 凸轮机构设计 漏 员员员是 6 SHANG 1日gG ERSITY
LECTURE 7 CAM DESIGN CAM DESIGN 凸轮机构设计
上游充通大学 SHANGHAI JIAO TONG UNIVERSITY .Cam >Convenient device for transforming one motion into another >Has a curved or grooved surface that mates with a follower =Imparts motion to follower Follower oscillation,translation,or both
•Cam ¾Convenient device for transforming one motion into Convenient device for transforming one motion into another ¾Has a curved or grooved surface that mates with a follower =Imparts motion to follower Follower oscillation translation or both Follower oscillation, translation, or both
上游充通大学 Cams compare with linkage SHANGHAI JLAO TONG UNIVERSITY .Linkage advantages >Reliability >Ease of construction >Lower cost .Cam-follower systems more compact than linkages >For same output motion >Can generate a true dwell >Intermittent motion ME357 Design Manufacturing ll
Cams compare with linkage •Linkage advantages Linkage advantages ¾Reliability ¾Ease of construction ¾Lower cost Lower cost •Cam -follower systems more compact than follower systems more compact than linkages ¾For same output motion ¾Can generate a true dwell Can generate a true dwell ¾Intermittent motion ME357 Design & Manufacturing II
上游充通大学 Cam Design Procedure SHANGHAI JIAO TONG UNIVERSITY Type Synthesis ● Selection of cam and follower type based on basic motion requirements 。 Geometric,environmental,and economic considerations Follower Motion Based on specified rise,return,dwell Dimensional Synthesis of Cam Profile ."Wrapping around"follower profile onto cam Analysis Pressure Angle,Radius of Curvature,Dimensional Constraints... ME357 Design Manufacturing ll
Cam Design Procedure Typ y e S ynthesis • Selection of cam and follower type based on basic motion requirements • Geometric, environmental, and economic considerations Follower Motion Follower Motion • Based on specified rise, return, dwell Di i l S th i f C P fil Dimensional Synthesis o f Cam Profil e • “Wrapping around” follower profile onto cam Ali na ys s • Pressure Angle, Radius of Curvature, Dimensional Constraints... ME357 Design & Manufacturing II
上浒文通大学 Cam Terminology SHANGHAI JIAO TONG UNIVERSITY Type of follower motion (rotation,translation) Type of joint closure (force,form) Type of follower (roller,mushroom,flat) Direction of follower motion (radial,axial) Type of motion constraints(critical extreme position(CEP)and critical path motion(CPM)) Type of motion program (rise-fall (RF),rise-fall- dwell (RFD),rise-dwell-fall-dwell(RDFD) ME357 Design Manufacturing Il
Cam Terminology Type of follower motion (rotation, translation) Type of joint closure (force, form) T f f ll ( ll h fl t) Type o f follower (roller, mus hroom, fl at) Direction of follower motion (radial, axial) Direction of follower motion (radial, axial) Type of motion constraints (critical extreme position(CEP) and critical path motion (CPM)) Type of motion program (rise Type of motion program (rise -fall (RF) rise fall (RF), rise -fall - dwell (RFD), rise-dwell-fall-dwell (RDFD) ME357 Design & Manufacturing II