A Systematic Approach to Power-Flow and Static-Force Analysis in Epicyclic Spur-Gear Trains

1993 ◽  
Vol 115 (3) ◽  
pp. 639-644 ◽  
Author(s):  
E. Pennestri` ◽  
F. Freudenstein
Keyword(s):  
Power Flow ◽  
Systematic Approach ◽  
Flow Analysis ◽  
Spur Gear ◽  
Input Power ◽  
Static Force ◽  
Force Analysis ◽  
Systematic Method ◽  
Gear Trains ◽  
Gear Drives

It is well known that the circulating power in gear trains can be many times greater than the input power. Such circumstances require that in the design of split-power gear drives, a preliminary power-flow analysis be carried out. In this investigation a systematic method for the power-flow and static-force analysis of spur-gear drives is presented. The manner in which the procedure is applied has some similarities with an algorithm for kinematic analysis previously suggested by one of the authors. Following a brief review of previous work, the theoretical bases of the new methodology of analysis are discussed and numerical examples developed.

A Simplified Approach for Force and Power-Flow Analysis of Compound Epicyclic Spur-Gear Trains

1992 ◽  
Author(s):  
L. Saggere ◽  
D. G. Olson
Keyword(s):  
Graph Theory ◽  
Kinematic Analysis ◽  
Power Flow ◽  
Flow Analysis ◽  
Spur Gear ◽  
Gear Train ◽  
Force Analysis ◽  
Power Flow Analysis ◽  
Torque Analysis ◽  
Gear Trains

Abstract After conceptual design and dimensional synthesis of a compound epicyclic gear train (EGT), its performance evaluation involves kinematic analysis, force analysis, torque analysis, and power-flow analysis. In recent years, graph theory has proven to be a powerful symbolic representation for design of mechanisms. Application of graph theory for the topological representation and kinematic analysis of EGTs is quite well established. However, graph theory based methods for power-flow and force analysis lack certain features, making them unsuitable or difficult to implement in a general purpose program for automatic design of EGTs. The traditional approach has been to perform force and torque analysis first, and then use the results to perform power-flow analysis. This paper presents a novel, systematic approach in which power-flow analysis is performed first, and then the results are used to determine the inter-link forces in epicyclic spur-gear trains. This method is based only on the graph of the gear-train and the angular velocities of the elements, and hence, is more suitable for automatic computation, simpler to implement in a program, and also avoids requiring the formulation of tedious torque equilibrium equations. A numerical example is presented to illustrate the simplicity and generality of the method.

scholarly journals The multi-attribute topological graph method and its application on power flow analysis in closed planetary gear trains

2018 ◽  
Vol 10 (8) ◽  
pp. 168781401879410 ◽  
Author(s):  
Yahui Cui ◽  
Jing Gao ◽  
Xiaomin Ji ◽  
Xintao Zhou ◽  
Haitao Yan
Keyword(s):  
Power Flow ◽  
Flow Analysis ◽  
Planetary Gear ◽  
Topological Graph ◽  
Template Model ◽  
Power Flow Analysis ◽  
Analysis Process ◽  
Planetary Gear Trains ◽  
Graphical View ◽  
Gear Trains

The concept of multi-attribute topological graph is proposed in this article to represent the characteristics of both structure and state for typical one-degree-of-freedom planar spur closed planetary gear trains. This method is well applied in power flow analysis and provides a graphical view for the types, values, directions, and transmission relationship of power flow, especially for the recirculation power representation. Furthermore, a template model of multi-attribute topological graph for closed planetary gear trains is also presented, which would be helpful to the multi-attribute topological graph generation for some certain types of closed planetary gear trains just by changing symbols in the template model. A corresponding software is also developed to make the analysis process more convenient. By inputting different parameters, the different visual results can be obtained automatically, thus benefiting engineers in conceptual design.

Nonlinear Input Power Flow Analysis of a Plate with a Breathing Crack

2014 ◽  
Vol 638-640 ◽  
pp. 163-167
Author(s):  
Zhong Hao Pang ◽  
Xiang Zhu ◽  
Tian Yun Li ◽  
Ling Zhang
Keyword(s):  
Nonlinear Dynamic ◽  
Power Flow ◽  
Damage Identification ◽  
Flow Analysis ◽  
Nonlinear Dynamic Analysis ◽  
Nonlinear Behavior ◽  
Input Power ◽  
Breathing Crack ◽  
Engineering Structures ◽  
Power Characteristics

Plates are commonly used in engineering structures. However crack is the most common form of damages in the plate structures. The crack in the plate will open and close during vibrational cycle, making the cracked structure with nonlinear dynamic characteristics. Based on vibrational power flow theory, the nonlinear dynamic analysis of a plate structure is carried out. The contact elements are used to simulate the nonlinear behavior of the breathing crack. Aiming to study the input power characteristics and the super harmonic resonance of a breathing cracked plate which is under the resonant excitation. By the finite element calculation, the structural input power curve is analyzed, which provides a theoretical basis for the damage identification of cracked structures.

Vibrational Power Flow Analysis of Stiffened Plate and Shell Structures

2011 ◽  
Vol 66-68 ◽  
pp. 1897-1901 ◽  
Author(s):  
Xiang Zhu ◽  
Gong Yu Xiao ◽  
Tian Yun Li ◽  
Xiao Fang Hu
Keyword(s):  
Cylindrical Shell ◽  
Power Flow ◽  
Flow Analysis ◽  
Flow Characteristics ◽  
Input Power ◽  
Shell Structures ◽  
Stiffened Plate ◽  
Simply Supported ◽  
Plate And Shell ◽  
Flow Vectors

In this paper, the vibration and power flow characteristics of stiffened plate and cylindrical shell structures are investigated by using finite element method. The power flow formulas of basic shell structural elements are given at first. Then a simply supported plate and stiffened plate’s input power flow characteristics and power flow vectors are investigated. The effects of stiffeners in plates are discussed. For a simply supported cylindrical shell, the influence of the structural damping, viscous damper and stiffeners on the cylindrical shell’s input power flow characteristics and propagated power flow characteristics are discussed in detail. The power flow vectors are visualized to reveal the distribution of energy in the shell structures. Some useful conclusions are drown and helpful for the vibration control of plate and shell structures.

Nomographs for Kinematics, Statics and Power Flow Analysis of Epicyclic Gear Trains

2009 ◽  
Author(s):  
Essam L. Esmail ◽  
Hamed A. Hussen
Keyword(s):  
Electric Motor ◽  
Power Flow ◽  
Automatic Transmission ◽  
Flow Analysis ◽  
Gear Train ◽  
Innovative Design ◽  
Epicyclic Gear ◽  
Power Split ◽  
Gear Trains ◽  
Flow Through

A new methodology for constructing multi-axes nomographs is developed. Using this methodology, a unified general formulation for computing velocities and torques of any epicyclic-type transmission train is presented. To demonstrate and apply the new technique, Ravigneaux automatic transmission is used to show how the velocities, the torques and the power flow through the train can be simultaneously visualized on a single nomograph. The present methodology is judged to be more efficient than other methods and than the three-ax nomograph methodology. Using this methodology an innovative design of two-input transmission with only one electric motor/generator (MG) and without any rotating clutches is presented. The proposed design provides some of the benefits and flexibility of a power-split design by using the conventionally available Ravigneaux gear train in a simpler mechanical layout which makes the design compact, mechanically simple, and operationally flexible.

scholarly journals A New Method to Perform Direct Efficiency Measurement and Power Flow Analysis in Vibration Energy Harvesters

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2388
Author(s):  
Jan Kunz ◽  
Jiri Fialka ◽  
Stanislav Pikula ◽  
Petr Benes ◽  
Jakub Krejci ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Polyvinylidene Fluoride ◽  
Power Flow ◽  
Flow Analysis ◽  
Lead Zirconate ◽  
Input Power ◽  
Mechanical Power ◽  
Vibration Source ◽  
Energy Harvesters ◽  
The Difference

Measuring the efficiency of piezo energy harvesters (PEHs) according to the definition constitutes a challenging task. The power consumption is often established in a simplified manner, by ignoring the mechanical losses and focusing exclusively on the mechanical power of the PEH. Generally, the input power is calculated from the PEH’s parameters. To improve the procedure, we have designed a method exploiting a measurement system that can directly establish the definition-based efficiency for different vibration amplitudes, frequencies, and resistance loads. Importantly, the parameters of the PEH need not be known. The input power is determined from the vibration source; therefore, the method is suitable for comparing different types of PEHs. The novel system exhibits a combined absolute uncertainty of less than 0.5% and allows quantifying the losses. The approach was tested with two commercially available PEHs, namely, a lead zirconate titanate (PZT) MIDE PPA-1011 and a polyvinylidene fluoride (PVDF) TE LDTM-028K. To facilitate comparison with the proposed efficiency, we calculated and measured the quantity also by using one of the standard options (simplified efficiency). The standard concept yields higher values, especially in PVDFs. The difference arises from the device’s low stiffness, which produces high displacement that is proportional to the losses. Simultaneously, the insufficient stiffness markedly reduces the PEH’s mechanical power. This effect cannot be detected via the standard techniques. We identified the main sources of loss in the damping of the movement by the surrounding air and thermal losses. The latter source is caused by internal and interlayer friction.

Design of Multiple Operating Degrees-of-Freedom Planetary Gear Trains With Variable Structure

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Zeng-Xiong Peng ◽  
Ji-Bin Hu ◽  
Tian-Li Xie ◽  
Chun-Wang Liu
Keyword(s):  
Power Flow ◽  
Degrees Of Freedom ◽  
Flow Analysis ◽  
Graph Model ◽  
Planetary Gear ◽  
Variable Structure ◽  
Planetary Gear Trains ◽  
Planetary Gear Sets ◽  
Gear Trains ◽  
Synthesis Methodology

To obtain multiple speed ratios, a synthesis methodology of planetary gear trains (PGTs) with multiple operating degrees-of-freedom (DOFs) is proposed based on the variable structure method. Variable structure of PGT is accomplished by changing the fixed interconnection edge. First, PGTs with two operating DOFs are synthesized with a deduction method based on the relationship between the number of planetary gear sets (PGSs) and number of fixed interconnection edges. Next, connection characteristics of fixed interconnection edges are defined as frequency of utilization to construct original speed ratios of the two operating DOFs schemes. The connection characteristics are then obtained based on the power flow analysis. PGT graph model with connection characteristic is built to provide guidance in the design of varying structure. Finally, multispeed PGTs with multiple operating DOFs are synthesized based on the graph model and lever analogy. A design example for three-PGS PGTs is considered to highlight capabilities of the variable structure method.

Dynamic Behavior of Finite Coupled Mindlin Plates With a Blocking Mass

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
XianZhong Wang
Keyword(s):  
Dynamic Behavior ◽  
Power Flow ◽  
Equations Of Motion ◽  
Flow Analysis ◽  
Input Power ◽  
Dynamic Responses ◽  
Structural Damping ◽  
Arbitrary Angle ◽  
Plate Equations ◽  
Coupled Plates

A power flow analysis of finite coupled Mindlin plates with a blocking mass at the junction of the coupled plates is investigated using the method of reverberation-ray matrix (MRRM). An exact solution is derived by the plate equations of motion to satisfy the boundary condition. The wave amplitude coefficients are obtained from the continuity conditions at driving force locations, and the line junction of two plates connected at an arbitrary angle. The blocking mass located at the junction of the two plates is modeled as a Timoshenko beam. The dynamic responses of the finite coupled Mindlin plates are verified by comparing with finite element method (FEM) results. The effects of the connected angles, blocking mass, and structural damping on the input power and transmitted power are calculated and analyzed. Numerical simulations of the finite coupled Mindlin plates with a blocking mass show that the present method can predict the dynamic behavior.

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