图 上海文通大￥ -b口 HAa JLAO TONr:UNpT LECTURE 5 ME371/ME337 DESIGN AND MANUFACTURING Graphical Linkage Synthesis Covered: Ch3-in Design of Machinery SHA 国 上海文通大学 OUTLINE ▣Kinematic Synthesis Dimensional Synthesis Quick-Return Mechanisms 1
1 Graphical Linkage Synthesis LECTURE 5 ME371/ME337 DESIGN AND MANUFACTURING Covered：Ch3- in Design of Machinery OUTLINE Kinematic Synthesis Dimensional Synthesis Quick-Return Mechanisms
国上泽发大半 Analysis OR Synthesis HAa ILAO ToNr:UNpi Analysis or Synthesis-A generic view (Uni-directional iterative Y2 among multiple points) Synthesis Analysis Synthesis Analysis X3 The Design Space The Performance Space (Sets of design parameters X (Sets of performance parameters Y and their specification ranges) and their requirement ranges) Most engineering design practice involves a combination of synthesis and analysis Kinematics:the study of the motion of mechanisms and methods of creating them. 国 上潘久大学 Kinematic Analysis Given a certain mechanism,the motion characteristics of its components will be determined by Kinematic Analysis. Task of analysis contains all principal dimensions of the mechanism,interconnections of its links,and the specification of the input motion or method of actuation. The objective is to find the displacements,velocities, accelerations,shock or jerk,as well as the paths described and motions performed by certain elements. T=Fn拼 Tout=Fout rout v->0 rock 2
2 Analysis or Synthesis-A generic view Y3 X2 X1 X3 Y2 Y1 The Design Space (Sets of design parameters X and their specification ranges) The Performance Space (Sets of performance parameters Y and their requirement ranges) Synthesis Analysis Synthesis Analysis (Uni-directional iterative among multiple points) Analysis OR Synthesis Most engineering design practice involves a combination of synthesis and analysis Kinematics : the study of the motion of mechanisms and methods of creating them. Kinematic Analysis Given a certain mechanism, the motion characteristics of its components will be determined by Kinematic Analysis. Task of analysis contains all principal dimensions of the mechanism, interconnections of its links, and the specification of the input motion or method of actuation. The objective is to find the displacements, velocities, accelerations, shock or jerk, as well as the paths described and motions performed by certain elements
图 上海文通大￥ Kinematic Synthesis HA ILAO ToNr:UNpin 国 Synthesis:the creation of potential solutions in the absence of a well defined algorithm which configures or predict the solution. The essence of Kinematic Synthesis is that the motion is given and the mechanism is to be found. The areas of synthesis may be grouped into two categories:type synthesis and dimensional synthesis. >Type synthesis:the definition of the proper type of mechanism best suited to the problem >Dimensional synthesis:the determination of the proportions (lengths)of the links necessary to accomplish the desired motions 国 上海文通大学 Kinematic Synthesis Design a mechanism to satisfy particular motion requirements. Functional relationship between input and output(linear to linear.linear to rotational.rotational to linear.rotational to rotational)(Function Generation) Follow a particular path(Path Generation) Be of a certain orientation at particular points(Motion Generation) Other considerations?: ·Full crank rotation ·Space Constraints ·Transmission Angle Mechanical Advantage 3
3 Kinematic Synthesis Synthesis: the creation of potential solutions in the absence of a well defined algorithm which configures or predict the solution. The essence of Kinematic Synthesis is that the motion is given and the mechanism is to be found. The areas of synthesis may be grouped into two categories: type synthesis and dimensional synthesis. Type synthesis: the definition of the proper type of mechanism best suited to the problem Dimensional synthesis: the determination of the proportions (lengths) of the links necessary to accomplish the desired motions Design a mechanism to satisfy particular motion requirements. • Functional relationship between input and output (linear to linear, linear to rotational, rotational to linear, rotational to rotational) (Function Generation) • Follow a particular path (Path Generation) • Be of a certain orientation at particular points (Motion Generation) Other considerations?: • Full crank rotation • Space Constraints • Transmission Angle • Mechanical Advantage Kinematic Synthesis
图上泽充大学 Task of kinematic synthesis GN如T94 Darte 4-Dar linkage Clozaifiostion 品D D Belt2 Most important step is to clarify the performance Path tenerate requirements with motions. The motions can be modeled graphically or analytically. 位 国 上潘久大学 OUTLINE ▣Kinematic Synthesis Dimensional Synthesis Quick-Return Mechanisms 4
4 Task of kinematic synthesis Most important step is to clarify the performance requirements with motions. The motions can be modeled graphically or analytically. Ⅰ Ⅱ D OUTLINE Kinematic Synthesis Dimensional Synthesis Quick-Return Mechanisms
图 上泽文通大学 Type synthesis TYPE SYNTHESIS:the definition of the proper type of mechanism best suited to the problem. 国 Example:Design a device to track the straight-line motion of a part on a conveyor belt and spray it with a chemical coating as it passes by. -High,constant speed; -A straight-line linkage -Good accuracy and repeatability -A cam and follower -reliable -An air cylinder -A hydraulic cylinder -A robot -A solenoid 国 上海文通大学 Dimensional synthesis Dimensional synthesis the determination of the proportions (lengths)of the links necessary to accomplish the desired motions. Through type synthesis,you have determined that a linkage is the most appropriate solution to the problem. The simplest and quickest methods are graphical.This is up to three design positions 5
5 TYPE SYNTHESIS : the definition of the proper type of mechanism best suited to the problem. Example: Design a device to track the straight-line motion of a part on a conveyor belt and spray it with a chemical coating as it passes by. Type synthesis Trade-off - High, constant speed; - Good accuracy and repeatability - reliable - A straight-line linkage - A cam and follower - An air cylinder - A hydraulic cylinder - A robot - A solenoid Dimensional synthesis : the determination of the proportions (lengths) of the links necessary to accomplish the desired motions. Through type synthesis, you have determined that a linkage is the most appropriate solution to the problem. The simplest and quickest methods are graphical. This is up to three design positions Dimensional synthesis