On the synthesis of a geared four-bar mechanism

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This study presents novel analysis and synthesis methods for a certain type of geared adjustable stroke mechanism. The mechanism has significance in mechanical design, as it has been used in practice. However, to the best of our knowledge, any theory on its analysis or synthesis is not available in the literature. The problem is divided into four parts and each part is generalized. Novel synthesis procedures for possible largest stroke are developed. Design charts are prepared for maximum stroke configuration. Stroke variation is an important concern in mechanism design. By adopting the introduced method, the output stroke can simply be adjusted even during the operation. The output stroke of the mechanism can be decreased more than 50% with proper transmission, velocity and acceleration characteristics. Use of non-integer gear ratio is also investigated. That property leads a variable stroke mechanism inherently. The relationship between the gear ratio and the number of cycles needed to return to the initial stroke value is determined. As a result, all possible design methods are investigated and generalized for this mechanism. Therefore, significant flexibility is introduced for adapting this mechanism to various practical applications.

Section: Introductionmentioning

confidence: 99%

On the synthesis of a geared adjustable stroke mechanism

Parlaktaş

2018

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“…Recent studies are generally about path generation (Russell and Shen, 2011), (Al-Smadi, et al, 2008), optimal design (Wang, et al, 2013), or geared linkages (Parlaktaş, et al, 2010). Special cases of four-bar linkages are used to obtain mechanical input-output relationship between spatially oriented axes of movement.…”

Section: Introductionmentioning

confidence: 99%

Fully compliant spatial four-bar mechanism

Tanık

Parlaktaş

2015

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This paper presents a novel study on the analysis of the "fully compliant" spatial four-bar mechanism. To the best of our knowledge, any research on "fully compliant" spatial four-bar mechanism is not available in the literature. In the previous study performed by the authors, a "partially compliant" version of the spatial four-bar mechanism was introduced. There was a rigid spherical joint in that case, thus there was no torsional loading at flexural hinges. For the fully compliant case, there is no spherical joint in the structure of the mechanism, thereby there is also torsion available at multiple axis flexural hinges. Design of this fully compliant mechanism is different from the partially compliant case. In this study, deflections of the multiple axis flexural hinges are determined separately as bending and twist. Essential angles for manufacturing a mechanism are determined. A prototype is built and results of the mathematical model are verified with experiments. Finally, a fatigue test is performed. After one and a half million cycles it is observed that there is no indication of any failure. Since there are many applications of rigid spatial four bar mechanisms, it is strongly believed that a fully compliant version of such a mechanism may also find applications.

“…Geared linkage mechanisms are composed of one or more linkages and gear pairs, and are widely used in machines and vehicles. Over the years, studies of geared linkage mechanisms have mainly focused on structural synthesis, kinematic analysis, and dimensional synthesis (Beiner, 2001, Buskiewicz, 2010, Hsu and Lam, 1993, Hsu and Hsu, 1997, Lee and Freudenstein, 1978, Lin and Chen, 2000, Lin, et al, 2004, Lin and Cao, 2005, Modler, et al, 2009, Mundo and Gatti, 2008, Mundo, et al, 2009, Parlaktas, et al, 2010. A number of researchers have applied graph theory to the structural synthesis of these mechanisms (Hsu and Lam, 1993, Hsu and Hsu, 1997, Lin and Chen, 2000, Lin, et al, 2004.…”

Section: Introductionmentioning

confidence: 99%

“…A number of researchers have applied graph theory to the structural synthesis of these mechanisms (Hsu and Lam, 1993, Hsu and Hsu, 1997, Lin and Chen, 2000, Lin, et al, 2004. Moreover, some interesting and important results have been obtained regarding kinematic synthesis and analysis, leading to desired kinematic functionalities such as optimum transmission, exact path generation, large swinging angle motions, step motions, and dwell motions (Beiner, 2001, Lee and Freudenstein, 1978, Lin and Cao, 2005, Parlaktas, et al, 2010. Synthesis of geared linkages with non-circular gears has also been studied (Mundo, et al, 2009, Mundo and Gatti, 2008, Mundo, et al, 2009.…”

Section: Introductionmentioning

confidence: 99%

Analysis of novel geared linkage mechanisms

Soong

2014

Two types of novel one-degree-of-freedom seven-bar geared linkage mechanism are presented. The proposed mechanisms consist of an elementary planetary gear train, a slider-crank mechanism or a Scotch yoke mechanism, and a slider-crank mechanism with a variable-length crank. The output link can generate two required output motion cycles while the input link completes a single motion cycle. The structure, graphical displacement analysis, kinematic analysis and dynamic analysis of these mechanisms are discussed. An example is provided to demonstrate the kinematic and dynamic characteristics of the proposed mechanisms.