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This paper presents a systematic design approach to synthesize feasible configurations of parallel transmissions for a hybrid electric vehicle using single electric motor/generator. Based on the studies of existing parallel hybrid systems, four main types of parallel hybrid transmissions are classified and studied. The mechanisms, which were studied in present research, are two degrees of freedom compound planetary gear trains consisting of two simple planetary gear trains. By applying the proposed design approach, twelve feasible mechanisms for parallel hybrid transmissions are generated. Then, four potential mechanisms, which are used in existing designs, are employed to systematically synthesize 37 corresponding feasible parallel hybrid transmissions, including some existing parallel systems. To demonstrate the feasibility of the synthesized systems, a new parallel hybrid transmission is taken arbitrarily as a numerical example to illustrate its working principle with operation modes, and kinematics and power flow analysis. [ABSTRACT FROM AUTHOR]

Number synthesis of kinematic chains is one of the major steps in the structural synthesis or conceptual design of mechanisms. The work presents a comprehensive literature review on the number synthesis of kinematic chains of mechanisms. The terminology and definitions regarding kinematic chains in literature are introduced first. Then, various methods for the number synthesis of kinematic chains are presented and discussed. Finally, the numbers of kinematic chains with up to 15 links and 7 degrees of freedom are listed. [ABSTRACT FROM AUTHOR]

Abstract: Generating generalized kinematic chains is one of the most important steps in the conceptual design or structural synthesis of mechanisms. An improved method for the systematic construction of generalized kinematic chains (including both kinematic chains and rigid chains) is presented based on two algorithms, namely the cut-links checking algorithm and Kuratowski (nonplanar) graph checking algorithm. Examples are provided to illustrate the algorithms. The atlases of generalized kinematic chains comprising up to sixteen links are listed. [Copyright &y& Elsevier]

Abstract: Antikythera mechanism should be the oldest astronomical geared calculator in the world. It is confirmed that the solar anomaly motion could display on the front dial even though the corresponding solar mechanism has been lost. This work focuses on the reconstruction synthesis of the lost solar mechanism and provides a systematic approach to generate all feasible designs. Based on the kinematic and mechanism analysis, the design specifications of three possible types concluded by different input conditions are obtained. Through a study of historical literature and the existing design, the required design constraints are further concluded. Then, according to the concepts of generalization and specialization as well as the manufacture consideration, four feasible designs, including Wright's design in 2002, are respectively synthesized for different input types. These designs are consistent with the scientific theories and techniques of the subject's time period and match the existing evidences. [Copyright &y& Elsevier]

Abstract: One of the major steps in the creative, conceptual, or structural synthesis of mechanical devices is to generate the necessary atlas of kinematic graphs or chains. The atlas of generalized kinematic chains includes the atlas of kinematic chains for mechanisms and the atlas of rigid chains for structures (clamping devices). This study provides an enumeration algorithm for constructing various atlases of generalized kinematic chains based on link assortments, Robinson''s method, generating function of planar blocks, Euler''s formula, and graph theory. Examples are provided. And, the numbers of generalized kinematic chains with up to twelve links are listed. [Copyright &y& Elsevier]

Abstract: A mechanism with multiple topological structures during the operation process is called a mechanism with variable topologies (MVT) or is called a variable chain. The kinematic joints whose types and/or motion orientations are changeable during the operation process of an MVT are called the variable joints. According to the fundamental concepts, simplified unified graph, coordinate sequence, and mobility criterion at each stage, a design methodology is proposed for the configuration synthesis of MVTs. Fundamental synthesizing corollaries are established first. The concept of the simplified unified graph that represents topological changes in an MVT is used to address the configurations of MVTs. A type of one step push-button stopper locks is used as illustrative examples. [Copyright &y& Elsevier]

Abstract: This paper presents a systematic procedure to count the number of planar mechanisms subject to design constraints from the candidate kinematic chains. The procedure is based on well-known principles that can be found in graph theory and combinatorial mathematics. A link-path is employed to include the design constraints that a number of specified joints must correspond to a number of specified links. Also, modified permutation groups, generating function, and Polya’s theory are used to count the number of non-isomorphic mechanisms with the required design constraints. Then the pattern inventory is used for the conceptual design of the identified mechanisms. The procedure can identify all of the non-isomorphic mechanisms in a specified kinematic chain. In addition, the procedure can be used to determine the isomorphic mechanisms in a straightforward manner. Three practical examples are included in the paper to illustrate the systematic nature of the proposed procedure; namely: the differential-type south pointing chariot, the Watt kinematic chain, and a variable-stroke engine. [Copyright &y& Elsevier]

Abstract: A reconstruction design approach for the lost Zhang Heng’s seismoscope, which was invented in ancient China in 132 AD, is proposed. Based on the literature review, the design requirements of Zhang Heng’s seismoscope are defined and concluded. Then, according to the concepts of generalization and specialization subject to the concluded design requirements, all feasible designs that are in accordance with the science theories and techniques of the subject time period are recreated. Two examples, one with five members and six joints and the other with six members and eight joints, of the interior mechanism of Zhang Heng’s seismoscope are derived with 8 and 26 solutions, respectively. And, this provides a logical foundation for generating all possible reconstruction designs of Zhang Heng’s seismoscope before new evidences are found. [Copyright &y& Elsevier]

Abstract: This paper presents a systematic approach for synthesizing novel configurations of totally integrated DC gear motors (DC motors and gear reducers). The topological structures, motion characteristics, and design constraints of existing DC gear motors are defined. And, the graph representations for each member and labels for magnetic circuits of integrated DC gear motors are defined. Desired configurations of DC motors integrated with a three-link and a four-link gear reducer are synthesized. And, one prototype of the three-link integrated BDC gear motor and another of the four-link integrated BLDC gear motors are presented. The results provide all possible basic configurations of the proposed novel integrated DC gear motors for further applications. [Copyright &y& Elsevier]

Abstract: This paper devotes to the combinatorial analysis of kinematic building blocks. Two categories, unrepeated and repeated combinations, of the enumeration issue are classified. Based on graph theory, a systematic approach valid for both two categories is presented for enumerating all possible and feasible combined configurations from the given power source and specific kinematic building blocks. Through the labeled arborescence representations for the combined configurations, the enumeration process is developed by adopting the algorithm of tree enumeration. Two examples are provided to illustrate the proposed approach for the unrepeated and repeated combinations respectively. Furthermore, the enumeration process is computerized to enumerate the results automatically. [Copyright &y& Elsevier]

Locks have been used in ancient China for several thousands of years. However, the historic records of Chinese locks are few and the literatures regarding the design considerations are not available. This work introduces the development and mechanisms of ancient Chinese padlocks and to present the design considerations including: specifications, opening methods, keyhole positions, configurations of spring mechanisms, shapes of keyheads and keyholes, appearance with suitable material, and engraving patterns on the lock surfaces. And, through the steps of handicraft, the ancient locks are endowed with rich vitality and technological values. [Copyright &y& Elsevier]

This paper presents a rules-based computerized symbolic carrier regeneration method for mechanical system conceptual design. In this method, design requirements of mechanical systems are expressed by regeneration rules which are composed mainly of symbols and logical codes; non-isomorphic graphs are chosen to be graphic carriers for symbolic carrier regeneration process; in each regeneration step, similarity identification needs to be done on symbolic carrier elements-links, so as to prevent redundant schemes. General design requirements can be expressed by simple Boolean calculation (AND, OR), relation calculation (adjacent, overlapping, topological relationship) and functional elements (concepts). Based on computer and object oriented encapsulation technology, the method can solve general conceptual design problems of mechanical systems. Designers need not know much about specialized knowledge and can fulfill design process of mechanical products. [Copyright &y& Elsevier]

This work presents a concept of elementary gear trains such that the tooth-profiles of the pinion are cylindrical. The pitch radius is replaced by the distance between the gear center and the tooth center as the radius of gears. Based on coordinate transformation, triple vector product of differential geometry, and theory of conjugate surfaces, equation of meshing is derived. A program is developed to solve the conjugate surface equations, and to show the solid modeling of the proposed elementary planetary gear trains. [Copyright &y& Elsevier]

The mechanical music automata have been developed since thousands years ago for mimicking sound of animals or playing a melody. They are documented and/or preserved in many countries, with solutions that reflect the evolution of mechanical manufacture and technology in these areas. In this article, a timeline of the ancient literature in both western and eastern countries is arranged to clarify the historical development of music-playing automata. The functional mechanical design parameters are arranged based on the four fundamental music characteristics as pitch, duration, intensity and timbre. Moreover, the mechanical music generators are also classified into wind, percussion, strings instruments and the steel music comb according to their composition. These music-playing automata are analyzed in four main units, namely power system, music generator, transmission and mechanical puppets. Finally, seven ancient automata are analyzed as illustrative examples from the viewpoint of mechanism design for these analysis and classification. [ABSTRACT FROM AUTHOR]