CRANK-ROCKER MECHANISM GROUP WITH A MAXIMUM TRANSMISSION ANGLE AT A CRANK ANGLE IS EQUAL TO 45 DEGREES

2017 ◽  
pp. 19-24
Author(s):  
N. A. Sereda
Keyword(s):  
Transmission Angle ◽  
Crank Angle ◽  
Maximum Transmission

MATHEMATICAL MODEL AND AREA OF EXISTENCE OF THE FAMILY CRANKS AND MOBILE MECHANISMS WITH THE MAXIMUM TRANSMISSION ANGLE

2020 ◽  
pp. 20-26
Author(s):  
N. A. Sereda
Keyword(s):  
Mathematical Model ◽  
New Family ◽  
Arm Span ◽  
Angle Function ◽  
Straight Line ◽  
Transmission Angle ◽  
Crank Angle ◽  
The Family ◽  
Unit Radius ◽  
Maximum Transmission

The article examines crank-rocker mechanisms. Such mechanisms are used in transport and technological machines. The article is devoted to the search for a new family of crank-rocker mechanisms. A mathematical model of a new family of crank-rocker mechanisms is obtained. In this family, the maximum transmission angle reaches 90 when the crank angle is 75. Thus, the new family of crank-rocker mechanisms differs from the known families by the position of the mechanism in which the maximum of the transmission angle function takes place. It is shown that, with a certain ratio of link lengths, the new family corresponds to the known families KKM-5 and KKM-7. The area of existence of a new family of crank-rocker mechanisms is established. This area is bounded by the arc of the circle of the unit radius and the curve. The mentioned curve is based on a joint solution of a mathematical model of a new family of mechanisms and the famous Kolchin straight line. The dependence for the minimum transmission angle is obtained. A formula for determining the angle of the rocker arm span is proposed. A graphical interpretation of the mentioned dependencies and formulas is constructed. The scope of existence of a new family of crank-rocker mechanisms and graphical interpretations are used in determining the geometric parameters of mechanisms. These mechanisms are part of a new family of mechanisms.

Design of Quick-Returning R-S-S-R Mechanisms

1988 ◽  
Vol 110 (4) ◽  
pp. 423-428 ◽  
Author(s):  
F. O. Suareo ◽  
K. C. Gupta
Keyword(s):  
Solution Space ◽  
Algebraic Method ◽  
Axial Distance ◽  
Link Length ◽  
Planar Case ◽  
Transmission Angle ◽  
Crank Angle ◽  
Shaft Angle ◽  
The Given ◽  
Crank Length

An algebraic method is presented to synthesize quick-returning R-S-S-R mechanisms which satisfy the given time-ratio and follower oscillation angle requirements. In these designs, the three parameters, which define the follower spheric joint, satisfy a quadratic condition. When the shaft angle between the input and output shafts is zero, this quadratic condition reduces to the equation of a circle which is a familiar classical result for the planar case. The solution space for the quick-returning R-S-S-R linkage is such that, for each set of choices for crank length a2, follower axial distance S4, and initial follower angle φ0, there are four sets of follower length a4, initial crank angle θ0, crank axial distance S2, and coupler length a3. These designs are screened so that they do not have branch defect, have transmission angle values in a given range, and have reasonable link length proportions.

Design of Drag-Link Mechanisms With Minimax Transmission Angle Deviation

1983 ◽  
Vol 105 (4) ◽  
pp. 686-690 ◽  
Author(s):  
L.-W. Tsai
Keyword(s):  
Optimum Design ◽  
Design Criterion ◽  
Parameter Design ◽  
Cubic Equation ◽  
Design Charts ◽  
Link Mechanism ◽  
Transmission Angle ◽  
Angle Deviation ◽  
Drag Link ◽  
Maximum Transmission

In this paper, the design equations are derived for the synthesis of a drag-link mechanism, with given output-link rotation and the corresponding input-link rotation. The design criterion used is based on the maximum capability of a drag-link mechanism to provide a given delay or advance in the output motion. The solutions are given as a single-valued parametric set of equations for the link lengths. The transmission-angle optimization is accomplished by the minimization of the maximum transmission-angle deviation from 90 deg. It is shown that the optimum design can be obtained by solving a cubic equation in a single parameter. Design charts for the optimum design of a drag-link mechanism were developed. It is also shown that there is a one-to-one correspondence between the design of a crank-and-rocker mechanism and the drag-link mechanism.

scholarly journals Secure and DoS-Resilient Fragment Authentication in CCN-Based Vehicular Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Sangwon Hyun ◽  
Hyoungshick Kim
Keyword(s):  
Vehicular Networks ◽  
Denial Of Service ◽  
Content Delivery ◽  
Dos Attacks ◽  
Promising Alternative ◽  
Content Centric Networking ◽  
Transmission Unit ◽  
Communication Environments ◽  
Maximum Transmission

Content-Centric Networking (CCN) is considered as a promising alternative to traditional IP-based networking for vehicle-to-everything communication environments. In general, CCN packets must be fragmented and reassembled based on the Maximum Transmission Unit (MTU) size of the content delivery path. It is thus challenging to securely protect fragmented packets against attackers who intentionally inject malicious fragments to disrupt normal services on CCN-based vehicular networks. This paper presents a new secure content fragmentation method that is resistant to Denial-of-Service (DoS) attacks in CCN-based vehicular networks. Our approach guarantees the authenticity of each fragment through the immediate fragment verification at interim nodes on the routing path. Our experiment results demonstrate that the proposed approach provides much stronger security than the existing approach named FIGOA, without imposing a significant overhead in the process. The proposed method achieves a high immediate verification probability of 98.2% on average, which is 52% higher than that of FIGOA, while requiring only 14% more fragments than FIGOA.

Stirling's air engine—a thermodynamic appreciation

2000 ◽  
Vol 214 (4) ◽  
pp. 511-536 ◽  
Author(s):  
A J Organ
Keyword(s):  
Particle Trajectory ◽  
Temperature Response ◽  
Fluid Particle ◽  
Drive Mechanism ◽  
Specific Output ◽  
Crank Angle

Stirling's original engine is remarkable for having been the first application of the thermal regenerator—and an instant technological success. While the patents and their intriguing history are the normal focus of study, this paper shifts attention to the insights afforded by reconstructing the thermodynamic personality of the engine itself. The kinematics of the drive mechanism are recovered, and volume variations determined as a function of crank angle. Recently developed thermodynamic tools are introduced and applied to the construction of the fluid particle trajectory map. The map forms the integration grid for calculation of the temperature response of the regenerator. The claim for 2 bhp from the original engine is explored. Potential is identified for an up-to-date version of Stirling's elegant concept in the form of cheap quiet power units of attractive specific output.

Dynamic Behavior of a Hydraulically Actuated Mechanism. Part 2: Nonlinear Character

1986 ◽  
Vol 108 (2) ◽  
pp. 250-254
Author(s):  
V. Venkatraman ◽  
R. W. Mayne
Keyword(s):  
Dynamic Response ◽  
Transient Response ◽  
Adequate Description ◽  
Linear Behavior ◽  
Transmission Angle ◽  
Dimensionless Groups ◽  
Hydraulically Actuated ◽  
Nonlinear Character ◽  
The Common ◽  
Nonlinear Nature

The first of these papers considering a hydraulically actuated mechanism presents the common oscillating cylinder arrangement and sets of equations which describe the dynamic system. It then defines dimensionless groups that characterize the actuator-mechanism and explores the quasi-linear behavior of the system. This present paper focuses on the nonlinear nature of the system. Effects of transmission angle, mechanism geometry and loading are considered as well as the range of operation in which the small perturbation behavior provides an adequate description of the dynamic response. The paper closes by identifying a new parameter which plays an important role in characterizing the dependence of the system transient response on mechanism geometry.

Study on the Effective Slab Width of Composite Cable-Stayed Bridge under Axial Force

2012 ◽  
Vol 568 ◽  
pp. 200-203
Author(s):  
Xiang Nan Wu ◽  
Xiao Liang Zhai ◽  
Ming Min Zhou
Keyword(s):  
Axial Force ◽  
Shear Lag ◽  
Distribution Law ◽  
Slab Width ◽  
Cable Stayed Bridge ◽  
Stay Cables ◽  
Transmission Angle ◽  
Effective Flange Width ◽  
Width Coefficient ◽  
Cable Stayed Bridges

There exist evident shear-lag phenomena in large-span composite cable-stayed bridges under the action of axial force, especially in the deck with double main girders. In order to discuss the distribution law of the effective flange width coefficient along the span, caused by axial force, finite element computations of five composite cable-stayed bridges and theoretical analysis have been performed. The transmission angle of axial force caused by the axial compression of stay cables was given, meanwhile the formulas for computation effective slab width coefficient under axial force were suggested.

Optimal Design of a 4-DOF SCARA Type Parallel Robot Using Dynamic Performance Indices and Angular Constraints

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
Songtao Liu ◽  
Tian Huang ◽  
Jiangping Mei ◽  
Xueman Zhao ◽  
Panfeng Wang ◽  
...  
Keyword(s):  
Optimal Design ◽  
Dynamic Performance ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Rigid Body Dynamics ◽  
Performance Indices ◽  
Global Dynamic ◽  
Transmission Angle ◽  
Body Dynamics ◽  
Rigid Design

This paper deals with the optimal design of a 4-DOF SCARA type (three translations and one rotation) parallel robot using dynamic performance indices and angular constraints within and amongst limbs. The architecture of the robot is briefly addressed with emphasis on the mechanical realization of the articulated traveling plate for achieving a lightweight yet rigid design. On the basis of the kinematic singularity analysis, two types of transmission angle constraints are considered to ensure the kinematic performance. A simplified model of rigid body dynamics is then formulated, with which two global dynamic performance indices are proposed for minimization by taking into account both inertial and centrifugal/Coriolis effects. In addition, the servomotor specifications are estimated using the Extended Adept Cycle. The proposed approach has successfully been employed to develop a prototype machine.

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