《Design and manufacturing（ME371、ME337）》课程教学资源（参考教材）《Design Of Machinery》（Robert Norton，2Nd Edition）

INTRODUCTION Dixon.J.R.,and C.Poli.(1995).Engineering Design and Design for Manufacturing-A Structured Approach.Field Stone Publishers:Conway,MA. Fey,V.,et al.(1994)."Application of the Theory oflnventive Problem Solving to Design and Manufacturing Systems."CIRP Annals,43(1),pp.107-110. Gordon,W.J.J.(1962).Symectics.Harper Row:New York. Haefele,W.J.(1962).Creativity and Innovation.Van Nostrand Reinhold:New York. Harrisberger,L.(1982).Engineersmanship.Brooks/Cole:Monterey,CA. Osborn,A.F.(1963).Applied Imagination.Scribners:New York. Pleuthner,W.(1956)."Brainstorming."Machine Design.January 12,1956. Soh,N.P.(1990).The Principles of Design.Oxford University Press:New York. Taylor,C.W.(1964).Widening Horizons in Creativity.John Wiley Sons:New York. Von Fange,E.K.(1959).Professional Creativity.Prentice-Hall:Upper Saddle River,NJ. For additional information on Human Factors,the following are recommended: Bailey,R.W.(1982).Human Performance Engineering:A Guidefor System Designers. Prentice-Hall:Upper Saddle River,NJ. Burgess,W.R.(1986).Designing for Humans:The Human Factor in Engineering.Petrocelli Books. Clark,T.S.,and E.N.Corlett.(1984).The Ergonomics of Workspaces and Machines.Taylor and Francis. Huchinson,R.D.(1981).New Horizons for Human Factors in Design.McGraw-Hill:New York. McCormick,D.J.(1964).Human Factors Engineering.McGraw-Hill:New York. Osborne,D.J.(1987).Ergonomics at Work.John Wiley Sons:New York. Pheasant,S.(1986).Bodyspace:Anthropometry.Ergonomics Design.Taylor and Francis. Salvendy,G.(1987).Handbook of Human Factors.John Wiley Sons:New York. Sanders,M.S.(1987).Human Factors in Engineering and Design.McGraw-Hill:New York. Woodson,W.E.(1981).Human Factors Design Handbook.McGraw-Hill:New York. For additional information on writing engineering reports,the following are recommended: Barrass,R.(1978).Scientists Must Write.John Wiley Sons:New York. Crouch,W.G.,and R.L.Zetler.(1964).A Guide to Technical Writing.The Ronald Press: New York. Davis,D.S.(1963).Elements of Engineering Reports.Chemical Publishing Co.:New York. Gray,D.E.(1963).So You Have to Write a Technical Report.Information Resources Press: Washington,D.C. Michaelson,H.B.(1982).How to Write and Publish Engineering Papers and Reports.ISI Press:Philadelphia,PA. Nelson,J.R.(1952).Writing the Technical Report.McGraw-Hill:New York

Dixon. J. R., and C. Poli. (1995). Engineering Design and Design for Manufacturing-A Structured Approach. Field Stone Publishers: Conway, MA. Fey, V., et aI. (1994). "Application of the Theory ofInventive Problem Solving to Design and Manufacturing Systems." CIRP Annals, 43(1), pp. 107-110. Gordon, W. J.J. (1962). Synectics. Harper & Row: New York. Haefele, W. J. (1962). Creativity and Innovation. Van Nostrand Reinhold: New York. Harrisberger, L. (1982). Engineersmanship. Brooks/Cole: Monterey, CA. Osborn, A. F. (1963). Applied Imagination. Scribners: New York. Pleuthner, W. (1956). "Brainstorming." Machine Design, January 12, 1956. Soh, N. P. (1990). The Principles of Design. Oxford University Press: New York. Taylor, C. W. (1964). Widening Horizons in Creativity. John Wiley & Sons: New York. Von Fange, E. K. (1959). Professional Creativity. Prentice-Hall: Upper Saddle River, NJ. For additional information on Human Factors, the following are recommended: Bailey, R. W. (1982). Human Performance Engineering: A Guidefor System Designers. Prentice-Hall: Upper Saddle River, NJ. Burgess, W. R. (1986). Designing for Humans: The Human Factor in Engineering. Petrocelli Books. Clark, T. S., and E. N. Corlett. (1984). The Ergonomics of Workspaces and Machines. Taylor and Francis. Huchinson, R. D. (1981). New Horizons for Human Factors in Design. McGraw-Hill: New York. McCormick, D. J. (1964). Human Factors Engineering. McGraw-Hill: New York. Osborne, D. J. (1987). Ergonomics at Work. John Wiley & Sons: New York. Pheasant, S. (1986). Bodyspace: Anthropometry, Ergonomics & Design. Taylor and Francis. Salvendy, G. (1987). Handbook of Human Factors. John Wiley & Sons: New York. Sanders, M. S. (1987). Human Factors in Engineering and Design. McGraw-Hill: New York. Woodson, W. E. (1981). Human Factors Design Handbook. McGraw-Hill: New York. For additional information on writing engineering reports, the following are recommended: Barrass, R. (1978). Scientists Must Write. John Wiley & Sons: New York. Crouch, W. G., and R. L. Zetler. (1964). A Guide to Technical Writing. The Ronald Press: New York. Davis, D. S. (1963). Elements of Engineering Reports. Chemical Publishing Co.: New York. Gray, D. E. (1963). So You Have to Write a Technical Report. Information Resources Press: Washington, D.C. Michaelson, H. B. (1982). How to Write and Publish Engineering Papers and Reports. ISI Press: Philadelphia, PA. Nelson, J. R. (1952). Writing the Technical Report. McGraw-Hill: New York

Chapter KINEMATICS FUNDAMENTALS Chance favors the prepared mind PASTEUR 2.0 INTRODUCTION This chapter will present definitions of a number of terms and concepts fundamental to the synthesis and analysis of mechanisms.It will also present some very simple but powerful analysis tools which are useful in the synthesis of mechanisms. 2.1 DEGREESOF FREEDOM(DOF) Any mechanical system can be classified according to the number of degrees of free- dom (DOF)which it possesses.The system's DOF is equal to the mumber of indepen- dent parameters (measurements)which are needed to uniquely define its position in space at any instant of time.Note that DOF is defined with respect to a selected frame of reference.Figure 2-1 shows a pencil lying on a flat piece of paper with an x,y coordi- nate system added.If we constrain this pencil to always remain in the plane of the pa- per,three parameters (DOF)are required to completely define the position of the pencil on the paper,two linear coordinates (x,y)to define the position of anyone point on the pencil and one angular coordinate (8)to define the angle of the pencil with respect to the axes.The minimum number of measurements needed to define its position are shown in the figure as x,y.and 8.This system of the pencil in a plane then has three DOF.Note that the particular parameters chosen to define its position are not unique.Any alternate set of three parameters could be used.There is an infinity of sets of parameters possible, but in this case there must be three parameters per set,such as two lengths and anan- gie,to define the system's position because a rigid body in plane motion has three DOF. 22

22 2.0 INTRODUCTION This chapter will present definitions of a number of terms and concepts fundamental to the synthesis and analysis of mechanisms. It will also present some very simple but powerful analysis tools which are useful in the synthesis of mechanisms. 2.1 DEGREESOF FREEDOM ( DOF) Any mechanical system can be classified according to the number of degrees of free￾dom (DOF) which it possesses. The system's DOF is equal to the number of indepen￾dent parameters (measurements) which are needed to uniquely define its position in space at any instant of time. Note that DOF is defined with respect to a selected frame of reference. Figure 2-1 shows a pencil lying on a flat piece of paper with an x, y coordi￾nate system added. If we constrain this pencil to always remain in the plane of the pa￾per, three parameters (DOF) are required to completely define the position of the pencil on the paper, two linear coordinates (x, y) to define the position of anyone point on the pencil and one angular coordinate (8) to define the angle of the pencil with respect to the axes. The minimum number of measurements needed to define its position are shown in the figure as x, y, and 8. This system of the pencil in a plane then has three DOF. Note that the particular parameters chosen to define its position are not unique. Any alternate set of three parameters could be used. There is an infinity of sets of parameters possible, but in this case there must be three parameters per set, such as two lengths and an an￾gie, to define the system's position because a rigid body in plane motion has three DOF

FIGURE 2-1 A rigid body in a plane has three DOF Now allow the pencil to exist in a three-dimensional world.Hold it above your desktop and move it about.You now will need six parameters to define its six DOF.One possible set of parameters which could be used are three lengths,(x,y.3,plus three an- gles (a,s.p).Any rigid body in three-space has six degrees offreedom.Try to identify these six DOF by moving your pencil or pen with respect to your desktop. The pencil in these examples represents a rigid body,or link,which for purposes of kinematic analysis we will assume to be incapable of deformation.This is merely a con- venient fiction to allow us to more easily define the gross motions of the body.We can later superpose any deformations due to external or inertial loads onto our kinematic motions to obtain a more complete and accurate picture of the body's behavior.But re- member,we are typically facing a blank sheet ofpaper at the beginning stage of the de- sign process.We cannot determine deformations of a body until we define its size,shape, material properties,and loadings.Thus,at this stage we will assume,for purposes of initial kinematic synthesis and analysis,that our kinematic bodies are rigid and massless. 2.2 TYPESOF MOTION A rigid body free to move within a reference frame will,in the general case,have com- plex motion,which is a simultaneous combination of rotation and translation.In three-dimensional space,there may be rotation about any axis (any skew axis or one of the three principal axes)and also simultaneous translation which can be resolved into components along three axes.In a plane,or two-dimensional space,complex motion be- comes a combination of simultaneous rotation about one axis(perpendicular to the plane) and also translation resolved into components along two axes in the plane.For simplic- ity,we will limit our present discussions to the case of planar (2-0)kinematic systems. We will define these terms as follows for our purposes,in planar motion:

Now allow the pencil to exist in a three-dimensional world. Hold it above your desktop and move it about. You now will need six parameters to define its six DOF. One possible set of parameters which could be used are three lengths, (x, y, z), plus three an￾gles (a, <1>, p). Any rigid body in three-space has six degrees of freedom. Try to identify these six DOF by moving your pencil or pen with respect to your desktop. The pencil in these examples represents a rigid body, or link, which for purposes of kinematic analysis we will assume to be incapable of deformation. This is merely a con￾venient fiction to allow us to more easily define the gross motions of the body. We can later superpose any deformations due to external or inertial loads onto our kinematic motions to obtain a more complete and accurate picture of the body's behavior. But re￾member, we are typically facing a blank sheet of paper at the beginning stage of the de￾sign process. We cannot determine deformations of a body until we define its size, shape, material properties, and loadings. Thus, at this stage we will assume, for purposes of initial kinematic synthesis and analysis, that our kinematic bodies are rigid and massless. 2.2 TYPESOF MOTION A rigid body free to move within a reference frame will, in the general case, have com￾plex motion, which is a simultaneous combination of rotation and translation. In three-dimensional space, there may be rotation about any axis (any skew axis or one of the three principal axes) and also simultaneous translation which can be resolved into components along three axes. In a plane, or two-dimensional space, complex motion be￾comes a combination of simultaneous rotation about one axis (perpendicular to the plane) and also translation resolved into components along two axes in the plane. For simplic￾ity, we will limit our present discussions to the case of planar (2-0) kinematic systems. We will define these terms as follows for our purposes, in planar motion:

24 DESIGN OF MACHINERY CHAPTER 2 Pure rotation the body possesses one point (center of rotation)which has no motion with respect to the "stationary"frame of reference.All other points on the body describe arcs about that center.A reference line drawn on the body through the center changes only its angular orientation. Pure translation all points on the body describe parallel (curvilinear or rectilinear)paths.A reference line drml"n on the body changes its linear position but does not change its angular orienta- tion. Complex motion a simultaneous combination of rotation and translation.Any reference line drawn on the body will change both its linear position and its angular orientation.Points on the body will travel nonparallel paths,and there will be,at every instant,a center of rota tion,which will continuously change location. Translation and rotation represent independent motions of the body.Each can ex- ist without the other.If we define a 2-D coordinate system as shown in Figure 2-1,the x and y terms represent the translation components of motion,and the e term represents the rotation component. 2.3 LINKS,JOINTS,AND KINEMATIC CHAINS We will begin our exploration of the kinematics of mechanisms with an investigation of the subject of linkage design.Linkages are the basic building blocks of all mechanisms. We will show in later chapters that all common forms of mechanisms (cams,gears,belts, chains)are in fact variations on a common theme of linkages.Linkages are made up of links and joints. A link,as shown in Figure 2-2,is an (assumed)rigid body which possesses at least two nodes which are points for attachment to other links. Binary link one with two nodes. Ternary link one with three nodes. Quaternary link one with four nodes. Nodes Binary link Ternary link Quaternary link FIGURE 2-2 Links of different order

Pure rotation the body possesses one point (center of rotation) which has no motion with respect to the "stationary" frame of reference. All other points on the body describe arcs about that center. A reference line drawn on the body through the center changes only its angular orientation. Pure translation all points on the body describe parallel (curvilinear or rectilinear) paths. A reference line drm\"n on the body changes its linear position but does not change its angular orienta￾tion. Complex motion a simultaneous combination of rotation and translation. Any reference line drawn on the body will change both its linear position and its angular orientation. Points on the body will travel nonparallel paths, and there will be, at every instant, a center of rota· tion, which will continuously change location. Translation and rotation represent independent motions of the body. Each can ex￾ist without the other. If we define a 2-D coordinate system as shown in Figure 2-1, the x and y terms represent the translation components of motion, and the e term represents the rotation component. 2.3 LINKS,JOINTS, AND KINEMATIC CHAINS We will begin our exploration of the kinematics of mechanisms with an investigation of the subject of linkage design. Linkages are the basic building blocks of all mechanisms. We will show in later chapters that all common forms of mechanisms (cams, gears, belts, chains) are in fact variations on a common theme of linkages. Linkages are made up of links and joints. A link, as shown in Figure 2-2, is an (assumed) rigid body which possesses at least two nodes which are points for attachment to other links. Binary link - one with two nodes. Ternary link - one with three nodes. Quaternary link - one with four nodes

KINEMATICS FUNDAMENTALS A joint is a connection between two or more links (at their nodes).which allows some motion,or potential motion,between the connected links.Joints (also called ki- nematic pairs)can be classified in several ways: I By the type of contact between the elements,line,point,or surface. 2 By the number of degrees of freedom allowed at the joint. 3 By the type of physical closure of the joint:either force or form closed. 4 By the number of links joined (order of the joint). Reuleaux [1]coined the term lower pair to describe joints with surface contact (as with a pin surrounded by a hole)and the term higher pair to describe joints with point or line contact.However,if there is any clearance between pin and hole (as there must be for motion),so-called surface contact in the pin joint actually becomes line contact, as the pin contacts only one "side"of the hole.Likewise,at a microscopic level,a block sliding on a flat surface actually has contact only at discrete points,which are the tops of the surfaces'asperities.The main practical advantage of lower pairs over higher pairs is their better ability to trap lubricant between their enveloping surfaces.This is especially true for the rotating pin joint.The lubricant is more easily squeezed out of a higher pair, nonenveloping joint.As a result,the pin joint is preferred for low wear and long life, even over its lower pair cousin,the prismatic or slider joint. Figure 2-3a shows the six possible lower pairs,their degrees of freedom,and their one-letter symbols.The revolute (R)and the prismatic (P)pairs are the only lower pairs usable in a planar mechanism.The screw (H),cylindric (C),spherical,and flat(F)low- er pairs are all combinations of the revolute and/or prismatic pairs and are used in spatial (3-D)mechanisms.The Rand P pairs are the basic building blocks of all other pairs which are combinations of those two as shown in Table 2-1. A more useful means to classify joints (pairs)is by the number of degrees of free- dom that they allow between the two elements joined.Figure 2-3 also shows examples TABLE 2-1 of both one-and two-freedom joints commonly found in planar mechanisms.Figure 2-3b The Six Lower Pairs shows two forms of a planar,one-freedom joint (or pair),namely,a rotating pin joint (R)and a translating slider joint (P).These are also referred to as full joints (i.e.,full Name IDOF)and are lower pairs.The pin joint allows one rotational DOF,and the slider joint DOF Cont- (Symbol) ains allows one translational DOF between the joined links.These are both contained within (and each is a limiting case of)another common,one-freedom joint,the screw and nut Revolute R (R) (Figure 2-3a).Motion of either the nut or the screw with respect to the other results in helical motion.If the helix angle is made zero,the nut rotates without advancing and it Prismatic 1 0 becomes the pin joint.If the helix angle is made 90 degrees,the nut will translate along (P) the axis of the screw,and it becomes the slider joint. Helical 1 Figure 2-3c shows examples of two-freedom joints (hlgher pairs)which simultaneously (H) RP allow two independent,relative motions,namely translation and rotation,between the joined Cylindric 2 RP links.Paradoxically,this two-freedom joint is sometimes referred to as a"halfjoint,"with (C) its two freedoms placed in the denominator.The half joint is also called a roll-slide joint Spherical because it allows both rolling and sliding.A spherical,or ball-and-socket joint (Figure 2-3a), (S) 3 RRR is an example of a three-freedom joint,which allows three independent angular motions be- tween the two links joined.This ball joint would typically be used in a three-dimensional Planar (F) 3 RPP mechanism,one example being the ball joints in an automotive suspension system

A joint is a connection between two or more links (at their nodes), which allows some motion, or potential motion, between the connected links. Joints (also called ki￾nematic pairs) can be classified in several ways: 1 By the type of contact between the elements, line, point, or surface. 2 By the number of degrees of freedom allowed at the joint. 3 By the type of physical closure of the joint: either force or form closed. 4 By the number of links joined (order of the joint). Reuleaux [1] coined the term lower pair to describe joints with surface contact (as with a pin surrounded by a hole) and the term higher pair to describe joints with point or line contact. However, if there is any clearance between pin and hole (as there must be for motion), so-called surface contact in the pin joint actually becomes line contact, as the pin contacts only one "side" of the hole. Likewise, at a microscopic level, a block sliding on a flat surface actually has contact only at discrete points, which are the tops of the surfaces' asperities. The main practical advantage of lower pairs over higher pairs is their better ability to trap lubricant between their enveloping surfaces. This is especially true for the rotating pin joint. The lubricant is more easily squeezed out of a higher pair, nonenveloping joint. As a result, the pin joint is preferred for low wear and long life, even over its lower pair cousin, the prismatic or slider joint. Figure 2-3a shows the six possible lower pairs, their degrees of freedom, and their one-letter symbols. The revolute (R) and the prismatic (P) pairs are the only lower pairs usable in a planar mechanism. The screw (H), cylindric (C), spherical, and flat (F) low￾er pairs are all combinations of the revolute and/or prismatic pairs and are used in spatial (3-D) mechanisms. The Rand P pairs are the basic building blocks of all other pairs which are combinations of those two as shown in Table 2-1. A more useful means to classify joints (pairs) is by the number of degrees of free￾dom that they allow between the two elements joined. Figure 2-3 also shows examples of both one- and two-freedom joints commonly found in planar mechanisms. Figure 2-3b shows two forms of a planar, one-freedom joint (or pair), namely, a rotating pin joint (R) and a translating slider joint (P). These are also referred to as full joints (i.e., full = 1 DOF) and are lower pairs. The pin joint allows one rotational DOF, and the slider joint allows one translational DOF between the joined links. These are both contained within (and each is a limiting case of) another common, one-freedom joint, the screw and nut (Figure 2-3a). Motion of either the nut or the screw with respect to the other results in helical motion. If the helix angle is made zero, the nut rotates without advancing and it becomes the pin joint. If the helix angle is made 90 degrees, the nut will translate along the axis of the screw, and it becomes the slider joint. Figure 2-3c shows examples of two-freedom joints (h1gherpairs) which simultaneously allow two independent, relative motions, namely translation and rotation, between the joined links. Paradoxically, this two-freedom joint is sometimes referred to as a "halfjoint," with its two freedoms placed in the denominator. The half joint is also called a roll-slide joint because it allows both rolling and sliding. A spherical, or ball-and-socket joint (Figure 2-3a), is an example of a three-freedom joint, which allows three independent angular motions be￾tween the two links joined. This ball joint would typically be used in a three-dimensional mechanism, one example being the ball joints in an automotive suspension system