Analysis of mechanical errors in disc cam mechanisms

2005 ◽  
Vol 219 (2) ◽  
pp. 209-224 ◽  
Author(s):  
L-I Wu ◽  
W-T Chang
Keyword(s):  
Exact Solution ◽  
Analytical Method ◽  
Sudden Change ◽  
Design Parameters ◽  
Combined Effects ◽  
Worst Case ◽  
Cam Mechanism ◽  
Radial Dimension ◽  
Cam Profile ◽  
Shift Angle

This paper presents an analytical method for analysing the mechanical errors of disc cam mechanisms. With the aid of parametric expressions of the cam profile and by employing the concept of equivalent linkage, the error of the follower motion that is due to the variation in each design parameter can be determined analytically. The resulting error equations do not really involve the location of the curvature centre of the cam profile, and thus locating the curvature centre of the cam profile is not essential. The method is validated through analysing a cam mechanism that has an invariant equivalent linkage, and thus an exact solution is available. Compared with the exact solutions, the predicted results have at least four-figure accuracy. For the roller follower cases, the pressure angle has most effect on the resulting error. Owing to the counteraction of the shift angle, the resulting error due to the radial dimension error of the cam profile has relatively smaller variation. In the worst case, owing to the combined effects of various design parameters, the accuracy of the follower motion may degrade considerably. The acceleration error functions have a sudden change at the ends of the motion.

Meshing Analysis of the Planetary Indexing Cam Mechanisms

2005 ◽  
Vol 127 (2) ◽  
pp. 340-346 ◽  
Author(s):  
Hao Wang ◽  
Ce Zhang ◽  
Zhongqin Lin and ◽  
Guanlong Chen
Keyword(s):  
The Self ◽  
Design Parameters ◽  
Continuous Curve ◽  
Cam Mechanism ◽  
Cam Profile ◽  
Transmission Structure ◽  
Intersection Points ◽  
Planetary Transmission ◽  
Pitch Curve

The planetary indexing cam mechanism is a type of indexing cam mechanism that employs planetary transmission structure. The mechanism is unusual compared to other planar cam mechanisms for the self-intersection occurs inevitably on the pitch curve of the cam. This results in the loss of contacts between a few rollers and cam profile. This paper investigates the effects of such loss of contacts on the transmission by analyzing the meshing procedure of the mechanism. The number of the self-intersection points on the pitch curve is determined in terms of the rotary index of the continuous curve. The meshing procedure is analyzed in detail and the pressure angles are calculated. The effects of the design parameters on the meshing status are studied and illustrated. At the end, it is pointed out that loss of contacts will not hamper the rightness of motion transfer in the mechanism if the design parameters are well selected.

Optimal design of control valves in magnetorheological fluid dampers using a nondimensional analytical method

2012 ◽  
Vol 24 (1) ◽  
pp. 108-129 ◽  
Author(s):  
Xiaocong Zhu ◽  
Xingjian Jing ◽  
Li Cheng
Keyword(s):  
Optimal Design ◽  
Analytical Method ◽  
Vibration Isolation ◽  
Control Valve ◽  
Analytical Models ◽  
Design Parameters ◽  
Clear Understanding ◽  
Element Analysis ◽  
Worst Case ◽  
Control Valves

The magnetorheological control valve is a key element in magnetorheological dampers to achieve controllable damping characteristics in practice. The optimal design of magnetorheological control valves with an annular flow structure in two configurations of coil wire placements is investigated using a nondimensional analytical method. The achievable performances of the magnetorheological control valve are formulated in terms of several important nondimensional design parameters, which are defined based on the analytical models considering both mechanical flow characteristics and magnetic flux conservation in magnetorheological fluids and valve materials with a clear understanding and convenient specification in optimization. The design method first identifies a few optimal internal parameters through maximizing a single-objective function with predefined constraints. This can avoid empirical difficulty or uncertainty in weight selection in conventional multiobjective optimization methods and guarantee the worst-case performance. Then, the inherent sensitivity of the achievable performance with respect to external parameters is analyzed to provide practical instructions for appropriate design of the magnetorheological control valve. Finally, the analytical optimal results are verified by a finite element analysis, and a comparison is conducted to illustrate the excellent performance of a vibration isolation system employing the optimally designed magnetorheological control valve.

Kinematic analysis and deformation of a planar lattice with an arbitrary number of panels

2020 ◽  
pp. 15-19
Author(s):  
M.N. Kirsanov
Keyword(s):  
Exact Solution ◽  
Kinematic Analysis ◽  
Arbitrary Number ◽  
Design Parameters ◽  
Lattice Deformation ◽  
Planar Lattice ◽  
Force Loading

Formulae are obtained for calculating the deformations of a statically determinate lattice under the action of two types of loads in its plane, depending on the number of panels located along one side of the lattice. Two options for fixing the lattice are analyzed. Cases of kinematic variability of the structure are found. The distribution of forces in the rods of the lattice is shown. The dependences of the force loading of some rods on the design parameters are obtained. Keywords: truss, lattice, deformation, exact solution, deflection, induction, Maple system. [email protected]

Synthesis of the internal parallel cam mechanism

1998 ◽  
Vol 212 (7) ◽  
pp. 577-585 ◽  
Author(s):  
M Nishioka ◽  
T Nishimura
Keyword(s):  
Parametric Analysis ◽  
Parallel Mechanism ◽  
Design Parameters ◽  
Cam Mechanism ◽  
Pressure Angle

Parallel cam mechanisms have been studied in different ways. In this paper, a parametric formulation which can cover every configuration of the parallel cam mechanism is derived. As a result of parametric analysis, a new, last mechanism was found. This cam is essentially an internal cam mechanism. Based on the assumption of an equally distributed roller follower, the basic configurations of the mechanism are derived from both the pressure angle and the undercutting constraints. As a result, the possible number of rollers per spider plate is two. Thus the feasible area of the design parameters of the mechanisms are obtained. The advantages of the mechanism over the conventional parallel mechanism are the saving of space and a larger angular stroke of output.

Study on the compound transmission mechanism of the curve-face gear based on screw theory

2017 ◽  
Vol 232 (17) ◽  
pp. 3115-3124 ◽  
Author(s):  
Chao Lin ◽  
Yanqun Wei ◽  
Zhiqin Cai
Keyword(s):  
Screw Theory ◽  
Transmission Mechanism ◽  
Tooth Surface ◽  
Design Parameters ◽  
Gear Pair ◽  
Face Gear ◽  
Cylindrical Gear ◽  
Cam Mechanism ◽  
Conjugate Surfaces ◽  
Curve Face

The compound transmission mechanism of curve-face gear is a new type of gear transmission based on the cam mechanism and the curve-face gear pair. It combines the transmission characteristics of the cam mechanism and noncircular bevel gear. When the compound transmission mechanism of curve-face gear is engaged in the meshing transmission, the rotating center of the cylindrical gear is fixed and used as the driving wheel, and the curve-face gear can generate the helical motion around the axis. In this paper, the meshing characteristics and motion laws of the compound transmission mechanism of the curve-face gear are studied based on the theory of screw. Based on the meshing theory of gears, the coordinate system of conjugate surfaces is established, the basic meshing theory and equation are obtained. On this basis, combined with the principle of the cam, the transmission principle is analyzed by the screw theory. The tooth surface equation of the compound transmission mechanism of curve-face gear is deduced based on the meshing theory and the related knowledge of geometry. The motion law of the curve-face gear and the change of the motion law with the change of the basic parameters of the gear pair with different design parameters are calculated and analyzed. An experimental platform is built to verify the law of motion, and the experimental results are compared with the theoretical values. The correctness of the theoretical analysis is verified, which provides a new way for the research of the compound transmission mechanism of the curve-face gear.

Reducing Design Margins by Adaptive Compensation for Thermal and Aging Variations

2012 ◽  
pp. 201-230
Author(s):  
Zhenyu Qi ◽  
Yan Zhang ◽  
Mircea Stan
Keyword(s):  
Design Parameters ◽  
Worst Case Analysis ◽  
Transimpedance Amplifier ◽  
Large Area ◽  
Negative Bias Temperature Instability ◽  
Worst Case ◽  
Adaptive Computation ◽  
Bias Temperature Instability ◽  
Computation Efficiency ◽  
On Chip

Corner-based design and verification are based on worst-case analysis, thus introducing over-pessimism and large area and power overhead and leading to unnecessary energy consumption. Typical case-based design and verification maximize energy efficiency through design margins reduction and adaptive computation, thus helping achieve sustainable computing. Dynamically adapting to manufacturing, environmental, and usage variations is the key to shaving unnecessary design margins, which requires on-chip modules that can sense and configure design parameters both globally and locally to maximize computation efficiency, and maintain this efficiency over the lifetime of the system. This chapter presents an adaptive threshold compensation scheme using a transimpedance amplifier and adaptive body biasing to overcome the effects of temperature variation, reliability degradation, and process variation. The effectiveness and versatility of the scheme are demonstrated with two example applications, one as a temperature aware design to maintain IONto IOFFcurrent ratio, the other as a reliability sensor for NBTI (Negative Bias Temperature Instability).

The Variational IterationMethod for Finding Exact Solution of Nonlinear Gas Dynamics Equations

2011 ◽  
Vol 66 (3-4) ◽  
pp. 161-164 ◽  
Author(s):  
Hossein Jafari ◽  
Ch. Chun ◽  
C.M. Khalique
Keyword(s):  
Exact Solution ◽  
Nonlinear Equations ◽  
Analytical Solutions ◽  
Analytical Method ◽  
Iteration Method ◽  
Gas Dynamics ◽  
Variational Iteration Method ◽  
Gas Dynamics Equations ◽  
Exact Analytical Solutions ◽  
Gas Dynamics Equation

The variational iteration method (VIM) proposed by Ji-Huan He is a new analytical method to solve nonlinear equations. In this paper, a modified VIM is introduced to accelerate the convergence of VIM and it is applied for finding exact analytical solutions of nonlinear gas dynamics equation.

Novel Cam Mechanism for Core Sampling of Variable Density Materials

2008 ◽  
Author(s):  
Carl B. Allsup ◽  
Ernest A. Franke ◽  
Thomas E. Lyons ◽  
Paul T. Evans
Keyword(s):  
Geometric Modeling ◽  
Variable Density ◽  
Design Decisions ◽  
Preliminary Testing ◽  
Cam Mechanism ◽  
Core Sampling ◽  
Complex Functions ◽  
Cam Profile ◽  
Multiple Field ◽  
Underwater Exploration

Project critical mission requirements often drive design decisions and processes. This was the case for National Aeronautics and Space Administration (NASA) funded DEep Phreatic THermal eXplorer (DepthX), an underwater robot designed to autonomously map, navigate, and acquire biological samples. Mission requirements led the authors to develop a novel core sampling mechanism for variable density materials. Preliminary testing was conducted on variable density materials simulating real world specimens to identify the series of motions to acquire an acceptable core and optimize the geometry of the coring tube. A geometric modeling approach with configuration functions was employed to design the overall mechanism and establish the cam profile. The design was tested and evaluated during multiple field expeditions to cenotes (sinkholes) in Mexico. The culmination of the preliminary testing and the selected design methodology resulted in a core sampling mechanism that is compact, has minimal operational torque requirements, and utilizes a single motor to complete a series of complex functions. Future applications are envisioned for space expeditions, underwater exploration, and medical sampling.

Sign in / Sign up

Export Citation Format

Share Document