scholarly journals Effect of Mechanism Error on Input Torque of Scroll Compressor

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Man Zhao ◽  
Shurong Yu ◽  
Chao Li ◽  
Yang Yu
Keyword(s):  
Adverse Effect ◽  
Rotational Speed ◽  
Fundamental Principle ◽  
Friction Loss ◽  
Machining Accuracy ◽  
Large Fluctuation ◽  
Connecting Rod ◽  
Scroll Compressor ◽  
Calculation Results ◽  
Input Torque

Based on the fundamental principle of plane four-bar mechanism, the force on the equivalent parallel four-bar mechanism was analyzed for scroll compressor with mini-crank antirotation, and the formula of input torque was proposed. The change of input torque caused by the mechanism size error was analyzed and verified with an example. The calculation results show that the mechanism size error will cause large fluctuation in input torque at the drive rod and connecting rod collinear and the fluctuation extreme value increases with rotational speed. Decreasing of the crankshaft eccentricity errors is helpful for reducing the effects of dimension error on input torque but will increase the friction loss of orbiting and fixed scroll wrap. The influence of size error should be considered in design in order to select suitable machining accuracy and reduce the adverse effect caused by size error.

Analysis of the Lubrication Regimes at the Small End and Big End of a Connecting Rod of a High Performance Motorbike Engine

2012 ◽  
Author(s):  
Luca Bertocchi ◽  
Matteo Giacopini ◽  
Daniele Dini
Keyword(s):  
Rotational Speed ◽  
High Speed ◽  
High Performance ◽  
Hydrodynamic Lubrication ◽  
Vertical Axis ◽  
Connecting Rod ◽  
Lubrication Regimes ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Squeeze Effect

In the present paper, the algorithm proposed by Giacopini et. al. [1], based on a mass-conserving formulation of the Reynolds equation using the concept of complementarity is suitably extended to include the effects of compressibility, piezoviscosity and shear-thinning on the lubricant properties. This improved algorithm is employed to analyse the performance of the lubricated small end and big end bearings of a connecting rod of a high performance motorbike engine. The application of the algorithm proposed to both the small end and the big end of a con-rod is challenging because of the different causes that sustain the hydrodynamic lubrication in the two cases. In the con-rod big end, the fluid film is mainly generated by the relative high speed rotation between the rod and the crankshaft. The relative speed between the two races forms a wedge of fluid that assures appropriate lubrication and avoids undesired direct contacts. On the contrary, at the con-rod small end the relative rotational speed is low and a complete rotation between the mating surfaces does not occurs since the con-rod only oscillates around its vertical axis. Thus, at every revolution of the crankshaft, there are two different moments in which the relative rotational speed between the con-rod and the piston pin is null. Therefore, the dominant effect in the lubrication is the squeeze caused by the high loads transmitted through the piston pin. In particular both combustion forces and inertial forces contribute to the squeeze effect. This work shows how the formulation developed by the authors is capable of predicting the performance of journal bearings in the unsteady regime, where cavitation and reformation occur several times. Moreover, the effects of the pressure and the shear rate on the density and on the viscosity of the lubricant are taken into account.

A Meridian Profile Obtained by No Restriction in Optimum Process

2015 ◽  
Author(s):  
Takuji Tsugawa
Keyword(s):  
Rotational Speed ◽  
Guide Vane ◽  
Friction Loss ◽  
Design Parameters ◽  
Optimum Process ◽  
Blade Number ◽  
Impeller Outlet ◽  
Normal Diameter ◽  
Specific Speed

In previous study of optimum meridian profile of impeller and guide-vane, almost all design parameters included in the specific speed and blade number are variable design parameters in optimum process. As the result, optimum specific speed and blade number were obtained. In the calculation, loss calculation consists of blade-to-blade diffusion loss and axial-symmetrical annular wall friction loss. The calculation result without annular friction loss head isn’t affected by normal diameter and rotational speed. In consideration of diffusion loss and annular friction loss, the result of calculation is affected by normal diameter and rotational speed. In this case study, normal diameter and rotational speed are also variable design parameters. The normal diameter is mid span impeller outlet diameter. So, normal velocity is peripheral velocity of mid span impeller outlet. The initial normal diameter is 100mm and the initial rotational speed is 1000min−1. And then, design parameters and all specification become variable. As there isn’t constant design parameter in this case study, there is no restriction in optimum process. As there is no restriction in optimum process, the best one optimum meridian profile can be obtained. In one case, the object function contains the efficiency and suction specific speed. In the other case, the object function contains the only efficiency. As the result, the optimum meridian profile of impeller and guide-vane can be obtained in each case.

Connecting Rod Machining Process Improvement

2014 ◽  
Vol 556-562 ◽  
pp. 1009-1012
Author(s):  
De Ying Sun
Keyword(s):  
Process Improvement ◽  
Dynamic Load ◽  
Paper Analysis ◽  
Machining Process ◽  
Machining Accuracy ◽  
Connecting Rod ◽  
Processing Efficiency ◽  
Improvement Plan ◽  
Analysis And Study

connecting rod parts except under larger dynamic load in the institutions, it is also connected with other parts, movement and direction, therefore, the part of the connecting rod connected with other parts on the machining accuracy is crucial. In this paper, analysis and study connecting rod machining process, through the improvement plan, ensure the accuracy of the important parts of the connecting rod parts and the connecting rod production and processing efficiency.

Application of Electrochemical Discharge Machining to Micro-Machining of Quartz

2014 ◽  
Vol 939 ◽  
pp. 161-168 ◽  
Author(s):  
Kun Ling Wu ◽  
Hsin Min Lee ◽  
Kuan Hwa Chin
Keyword(s):  
Feed Rate ◽  
Rotational Speed ◽  
Processing Parameters ◽  
Machining Accuracy ◽  
Machining Performance ◽  
Process Technology ◽  
Machining Time ◽  
Optimal Processing ◽  
Electrochemical Discharge Machining ◽  
Electrochemical Discharge

Electrochemical discharge machining (ECDM) is the preferred non-traditional process technology in recent years, The main processing is applied to machining non-conductive hard brittle materials. This study investigated the precision and stability of quartz fabricated by ECDM and explored the optimal processing parameters including size of electrode, machining speed as well as pulse-on and pulse-off duration. Microgrooves machined under the optimal processing parameters with adjusted rotational speed and feed rate were examined to understand the effect of different ECDM parameters on machining performance. The results indicate that micro-holes of better morphology could be obtained under pulse voltage of 40 V, electrolyte concentration of 5 M, electrode size of 125 μm. Moreover, rotational speed of 1500 rpm and pulse-on/pulse-off (ms) ratio of 1:0.6 gave higher machining accuracy with smaller hole diameter and shorter machining time. Finally, microgrooves machined under the optimal processing parameters showed the best accuracy in dimension and cross-sectional morphology at rotational speed of 2500 rpm, pulse-on /pulse-off (ms) ratio of 1:1.6, and feed rate of 3000 μm/min.

Visual Design and Computational Analysis of the Hydraulic Support Based on MATLAB

2013 ◽  
Vol 470 ◽  
pp. 357-361
Author(s):  
Yan Qi Niu ◽  
Ming Zhong Li ◽  
Fei Ding ◽  
Wei Liu
Keyword(s):  
Design Process ◽  
Computational Analysis ◽  
Visual Design ◽  
Connecting Rod ◽  
Hydraulic Support ◽  
Support Design ◽  
Visual Computing ◽  
Calculation Results ◽  
Design Requirements ◽  
Hydraulic Supports

In the fully mechanized coalmining face, all the main hydraulic supports have the four-bar connecting rod. The design of the four-link mechanism is an important part of the modern hydraulic support design. This paper has analyzed the hydraulic supports four-bar connecting rod design process according to the deflective mount of the top beam. Simplified support model has written kinematic and mechanical equations of the four-bar type hydraulic support. This paper has proposed a method which can design the four connecting rod of hydraulic support based on matlab and solve nonlinear equations of kinematics, and has compiled into a visual computing program. Gives an example of the design requirements, applying this procedure design and calculation parameters of the hydraulic support, and using the AutoCAD drawing to verify results, calculation results are correct. The program improves efficiency of the hydraulic support design. The application of this procedure can be repeated, variables are modified until getting a satisfactory design results.

Research on Triaxial Linkage and Cut Point Tracking for Automotive Crankshaft Servo Grinder and its Key Technology

2011 ◽  
Vol 66-68 ◽  
pp. 419-423
Author(s):  
Xing Hong Huang ◽  
Xu Hua Pan ◽  
Xing Wu ◽  
Wen Guang Huang
Keyword(s):  
Dynamic Performance ◽  
Machining Accuracy ◽  
Connecting Rod ◽  
Precision Grinding ◽  
Cut Point ◽  
Point Tracking ◽  
Straight Line ◽  
Line Measurement ◽  
Ultra Precision ◽  
On Line

Based on the principle analysis of two-axis linkage and cut point tracking crankshaft servo grinding technology, the principle of triaxial linkage and cut point tracking for crankshaft servo grinding is analyzed and researched on the technological advantages for the neck of crankshaft connecting rod and the spindle neck. Then the dynamic grinding model is established, and the high-precision liquid hydrostatic slide-way technology, high rigidity straight line drive technology and on-line measurement and error compensation technology are employed synthetically to solve the dynamic performance of moving parts for ultra-precision grinding and its influence on the machining accuracy successfully. The problem of using common corundum wheel to process the crankshaft neck and connecting rod efficiently and accurately is conquered.

Dynamic Stability of the Flexible Connecting Rod of a Slider Crank Mechanism

1986 ◽  
Vol 108 (4) ◽  
pp. 487-496 ◽  
Author(s):  
Iradj G. Tadjbakhsh ◽  
Christos J. Younis
Keyword(s):  
Material Properties ◽  
Floquet Theory ◽  
Equation Of Motion ◽  
Connecting Rod ◽  
Linear Ordinary Differential Equations ◽  
Stability And Instability ◽  
Regions Of Stability ◽  
Modal Coordinates ◽  
Crank Mechanism ◽  
Input Torque

The partial differential equation of motion of the flexible connecting rod of a slider crank is derived, under the assumption of small deflections. Application of the Galerkin procedure, leads to a system of linear ordinary differential equations, with respect to the modal coordinates of vibration of the rod. For periodic solutions, the foregoing system reduces to a system of coupled Hill equations. Application of Floquet theory, determines those values of the parameters: speed, input torque, geometry, and material properties that constitute the boundaries between the regions of stability and instability.

scholarly journals The influence of load distribution in kinematic constraints of connecting rod on the results of the stress simulation

2017 ◽  
Vol 170 (3) ◽  
pp. 84-87
Author(s):  
Paweł MAGRYTA ◽  
Konrad PIETRYKOWSKI ◽  
Michał BIAŁY ◽  
Marcin SZLACHETKA
Keyword(s):  
Boundary Conditions ◽  
Load Distribution ◽  
Compressive Force ◽  
Compression Tests ◽  
Connecting Rod ◽  
Simulation Tools ◽  
Calculation Results ◽  
Mesh Grid ◽  
The Impact ◽  
Stress Simulation

The article presents the results of simulations research carried out, using Finite Element Method. The simulations were made in the Abaqus software. Calculations were made on the connecting rod of opposed piston engine. The connecting rod was subjected to a compression tests. Different versions of the boundary conditions in the form of load forces and pressure distribution acting on the small end of the connecting rod were presented. Depending on the load distribution acting on the connecting rod small end, different distributions of stresses in the connecting rod geometry were obtained. All studies were performed for the same geometry, the same mesh grid, and for the same value of compressive force (research could be considered as comparable). Changing the size and distribution of stresses in the connecting rod, evidence the impact of the adopted boundary conditions of the load distribution on the calculation results. It is important for the use of modern simulation tools in the design process of new mechanical parts.

scholarly journals Estimation of Design Parameters of the Crank-Connecting Rod Mechanism of Engines for Mobile Agricultural Machines

2021 ◽  
Vol 37 ◽  
pp. 00076
Author(s):  
F. Khaliullin ◽  
G. Pikmullin ◽  
A. Nurmiev ◽  
M. Lushnov
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Design Model ◽  
Design Parameters ◽  
Combustion Engines ◽  
Connecting Rod ◽  
Mass Model ◽  
Calculation Results ◽  
The Masses ◽  
Lumped Masses

An accurate choice of the design model of the crank-connecting rod mechanism of piston internal combustion engines affects the accuracy of the calculation results and their complexity. At present, most of scientists and technicians choose a two-mass design model to analyze the operation of the crankconnecting rod mechanism. The model considers only the rotational and reciprocating movements of two masses, which are connected by a rigid weightless rod. This model significantly simplifies the calculations, neglects the elastic deformations of the parts of the crank-connecting rod mechanism, and eliminates the need for compiling the equations of dynamics in partial derivatives. However, the model has a number of drawbacks. The calculation results obtained using the two-mass model exhibit significant errors, which mainly depend on the design features of the connecting rod assembly. The paper discusses multi-mass design models, where the connecting rod assembly can comprise several lumped masses located along its length. In this case, the plane-parallel motion of these masses is added. The masses have weightless and absolutely rigid bonds. Forces and moments acting on the piston assembly and the crank are calculated according to the equations compiled. Comparison of the calculation results with the results obtained for a two-mass model can be used to determine errors and choose a design model that provides the required accuracy. The considered design model is of interest to engineers and technicians engaged in the design and calculation of the crank-connecting rod mechanism of piston internal combustion engines.

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