Tham khảo tài liệu 'sổ tay tiêu chuẩn thiết kế máy p48', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CHAPTER 41 LINKAGES Richard E. Gustavson Technical Staff Member The Charles Stark Draper Laboratory Inc. Cambridge Massachusetts BASIC LINKAGE CONCEPTS MOBILITY CRITERION ESTABLISHING PRECISION POSITIONS PLANE FOUR-BAR LINKAGE PLANE OFFSET SLIDER-CRANK LINKAGE I KINEMATIC ANALYSIS OF THE PLANAR FOUR-BAR LINKAGE DIMENSIONAL SYNTHESIS OF THE PLANAR FOUR-BAR LINKAGE MOTION GENERATION DIMENSIONAL SYNTHESIS OF THE PLANAR FOUR-BAR LINKAGE CRANKANGLE COORDINATION POLE-FORCE METHOD SPATIAL LINKAGES REFERENCES Linkages are mechanical devices that appear very straightforward to both analyze and design. Given proper technique that is generally the case. The methods described in this chapter reveal the complexity and I think the beauty of linkages. I have gained significant satisfaction during my 20 years of work with them from both theoretical and functioning hardware standpoints. BASIC LINKAGE CONCEPTS Kinematic Elements A linkage is composed of rigid-body members or links connected to one another by rigid kinematic elements or pairs. The nature of those connections as well as the shape of the links determines the kinematic properties of the linkage. Although many kinematic pairs are conceivable and most do physically exist only four have general practical use for linkages. In Fig. the four cases are seen to include two with 1 degree of freedom f 1 one with f 2 and one with f 3. Single-degree-of-freedom pairs constitute joints in planar linkages or spatial linkages. The cylindrical and spherical joints are useful only in spatial linkages. The links which connect these kinematic pairs are usually binary two connections but may be tertiary three connections or even more. A commonly used tertiary link is the bell crank familiar to most machine designers. Since our primary STANDARD HANDBOOK OF MACHINE DESIGN CYLINDRICAL C SPHERICAL G FIGURE .
