scholarly journals A calculation method of transmission efficiency for RV reducer

2021 ◽  
Vol 9 (4B) ◽  
Author(s):  
Cheng Wang ◽  
Keyword(s):  
Calculation Method ◽  
Industrial Robot ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Gear Train ◽  
Graph Representation ◽  
Design Parameters ◽  
Virtual Power ◽  
Power Theory ◽  
Rv Reducer

RV reducer is the core component of industrial robot. It is of great significance to raise the transmission efficiency of RV reducer for improving the transmission performance of industrial robot. RV reducer belongs to the 2K-V type planetary gear train and consists of an equal speed ratio mechanism. Therefore, according to the structural characteristics of RV reducer, the virtual power theory and split power theory are adopted, and a calculation method of transmission efficiency for RV reducer is proposed. Firstly, the structure of a common RV reducer is introduced. Related structural analysis, kinematic analysis, and loaded analysis are given. Secondly, RV reducer is represented by the method of graph theory. By the virtual power theory and split power theory, the power flow direction is determined, and the values of split powers are calculated. Finally, according to the graph representation for RV reducer and the calculation principle of meshing power loss of planetary gear, the power losses of meshing gear pairs are calculated, respectively. According to the input and output values described in graph representation of RV reducer, the formula of transmission efficiency for RV reducer is derived. The calculation of transmission efficiency for RV-40E reducer is considered as an example. The result is compared with previous work on the subject, and the relations between design parameters and transmission efficiency of RV reducer are discussed.

The effect of planetary gear/star gear on the transmission efficiency of closed differential double helical gear train

2020 ◽  
Vol 234 (21) ◽  
pp. 4215-4223
Author(s):  
Cheng Wang
Keyword(s):  
Power Flow ◽  
Power Transmission ◽  
Flow Direction ◽  
Load Capacity ◽  
Research Work ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Helical Gear ◽  
Gear Train ◽  
Graph Representation

The research of transmission efficiency is of great significance for reducing energy consumption and improving the performance of the device. Researchers have done a lot of work on the calculation of transmission efficiency. However, in the present research work, the quantity of planetary gear/star gear is usually not considered and only a planetary gear/star gear is adopted in the gear transmission efficiency. In practice, in order to increase the stiffness and load capacity of gear train, a plurality of planetary gear/star gears is adopted. The closed differential double helical gear train has been widely used in many fields, such as the main reducer of aircraft engine, lifting mechanism, and the power transmission system of marine ships. Therefore, in this paper, the closed differential double helical gear train is taken as the research object and the effect of planetary gear/star gear on the transmission efficiency is analyzed. Firstly, according to the structure of closed differential double helical gear train, related kinematic analysis is given. Secondly, a graph representation is used to characterize the closed differential double helical gear train. According to the theory of virtual power, the power flow direction of closed differential double helical gear train is determined and the value of split power is obtained. According to the input and output values described in graph representation of closed differential double helical gear train, the formula of transmission efficiency is derived and the effects of planetary gear/star gear on transmission efficiency are analyzed. Finally, an illustrative example shows that compared with the theoretical value, the difference considering the effect of planetary gear/star gear on the transmission efficiency of closed differential double helical gear train is two percentage points.

A New Technique Based on Loops to Investigate Displacement Isomorphism in Planetary Gear Trains

2002 ◽  
Vol 124 (4) ◽  
pp. 662-675 ◽  
Author(s):  
V. V. N. R. Prasad Raju Pathapati ◽  
A. C. Rao
Keyword(s):  
Graph Isomorphism ◽  
Planetary Gear ◽  
Degree Of Freedom ◽  
Gear Train ◽  
Graph Representation ◽  
Kinematic Structure ◽  
Graph Representations ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
A New Technique

The most important step in the structural synthesis of planetary gear trains (PGTs) requires the identification of isomorphism (rotational as well as displacement) between the graphs which represent the kinematic structure of planetary gear train. Previously used methods for identifying graph isomorphism yielded incorrect results. Literature review in this area shows there is inconsistency in results from six link, one degree-of-freedom onwards. The purpose of this paper is to present an efficient methodology through the use of Loop concept and Hamming number concept to detect displacement and rotational isomorphism in PGTs in an unambiguous way. New invariants for rotational graphs and displacement graphs called geared chain hamming strings and geared chain loop hamming strings are developed respectively to identify rotational and displacement isomorphism. This paper also presents a procedure to redraw conventional graph representation that not only clarifies the kinematic structure of a PGT but also averts the problem of pseudo isomorphism. Finally a thorough analysis of existing methods is carried out using the proposed technique and the results in the category of six links one degree-of-freedom are established and an Atlas comprises of graph representations in conventional form as well as in new form is presented.

Dynamic Analysis of Helical Planetary Gear Train

2013 ◽  
Vol 404 ◽  
pp. 312-317 ◽  
Author(s):  
Xian Zeng Liu ◽  
Jun Zhang
Keyword(s):  
Steady State ◽  
Free Vibration ◽  
Dynamic Model ◽  
Planetary Gear ◽  
Gear Train ◽  
Dynamic Responses ◽  
Design Parameters ◽  
Planetary Gear Train ◽  
State Dynamic ◽  
The Impact

A dynamic model for helical planetary gear train (HPGT) is proposed. Based on the model, the free vibration characteristics, steady-state dynamic responses and effects of design parameters on system dynamics are investigated through numerical simulations. The free vibration of the HGPT is classified into 3 categories. The classified vibration modes are demonstrated as axial translational and torsional mode (AT mode), radial translational and rotational mode (RR mode) and planet mode (P mode) followed by the characteristics of each category. The simulation results agree well with those of previous discrete model when neglecting the component flexibilities, which validates the correctness of the present dynamic model. The steady-state dynamic responses indicate that the dynamic meshing forces fluctuate about the average static values and the time-varying meshing stiffness is one of the major excitations of the system. The parametric sensitivity analysis shows that the impact of the central component bearing stiffness on the dynamic characteristic of the HPGT system is significant.

Extension of Graph Theory to the Duality Between Static Systems and Mechanisms

2005 ◽  
Vol 128 (1) ◽  
pp. 179-191 ◽  
Author(s):  
Offer Shai ◽  
Gordon R. Pennock
Keyword(s):  
Flow Line ◽  
Line Graph ◽  
Planetary Gear ◽  
Gear Train ◽  
Graph Representation ◽  
Static System ◽  
Graph Representations ◽  
Dual Transformation ◽  
Serial Robot ◽  
The Stability

This paper is a study of the duality between the statics of a variety of structures and the kinematics of mechanisms. To provide insight into this duality, two new graph representations are introduced; namely, the flow line graph representation and the potential line graph representation. The paper also discusses the duality that exists between these two representations. Then the duality between a static pillar system and a planar linkage is investigated by using the flow line graph representation for the pillar system and the potential line graph representation for the linkage. A compound planetary gear train is shown to be dual to the special case of a statically determinate beam and the duality between a serial robot and a platform-type robot, such as the Stewart platform, is explained. To show that the approach presented here can also be applied to more general robotic manipulators, the paper includes a two-platform robot and the dual spatial linkage. The dual transformation is then used to check the stability of a static system and the stationary, or locked, positions of a linkage. The paper shows that two novel platform systems, comprised of concentric spherical platforms inter-connected by rigid rods, are dual to a spherical six-bar linkage. The dual transformation, as presented in this paper, does not require the formulation and solution of the governing equations of the system under investigation. This is an original contribution to the literature and provides an alternative technique to the synthesis of structures and mechanisms. To simplify the design process, the synthesis problem can be transformed from the given system to the dual system in a straightforward manner.

Random vibration analysis of thin-walled elastic rings under multiple moving loads

2021 ◽  
pp. 095440622199640
Author(s):  
Jalal Taheri Kahnamouei ◽  
Jianming Yang
Keyword(s):  
Random Vibration ◽  
Planetary Gear ◽  
Gear Train ◽  
Design Parameters ◽  
Ring Gear ◽  
Moving Loads ◽  
Newmark Scheme ◽  
Mean And Variance ◽  
Thin Walled ◽  
Bolt Connection

This paper investigates the random vibration of a thin-walled ring subjected to multiple moving loads from the inside of the ring. A ring gear in a planetary gear train with three equally-spaced planets is taken as an example. The ring is discretized with the finite element method of curved beam elements. The supports of the ring gear are treated as three linear springs to mimic a general bolt connection. The stochastic Newmark algorithm is used to solve the equations and obtain the response's mean and variance. Monte Carlo simulations are also conducted to verify the results from the stochastic Newmark scheme. A parametric study is conducted to examine the effect of design parameters on the responses.

Multi-Objective Optimization for the Efficiency and Weight of Helicopter Transmission Planetary Gear Train

2014 ◽  
Vol 635-637 ◽  
pp. 177-180
Author(s):  
Kang Huang ◽  
Xiao Hui Zhu ◽  
Xiang Chen ◽  
Gong Chuan Xia
Keyword(s):  
Planetary Gear ◽  
Optimization Method ◽  
Gear Train ◽  
Transmission Ratio ◽  
Design Parameters ◽  
Multi Objective Optimization ◽  
Planetary Gear Train ◽  
Multi Objective ◽  
Critical Design ◽  
Helicopter Transmission

A multi-objective optimization method for the optimization of the efficiency and weight of helicopter transmission planetary gear train was established. Taking the transmission ratio, efficiency weight, and reliability as critical design parameters, taking the conditions of the planetary gear train itself and the strength check constraint for the gear train as constraint functions, making the weight and efficiency of the planetary gear train asoptimization targets and using the Matlab function fgoalattain, a multi-objective optimization has been made. Comparison between the initial and the optimized results showed the success of the optimized planetary gear train in reducing the weight and increasing the efficiency.

Investigation on the Transmission Efficiency of the Planetary Gear Train

2011 ◽  
Vol 103 ◽  
pp. 205-208 ◽  
Author(s):  
Li Feng Chen ◽  
Xiao Ling Wu ◽  
Da Tong Qin ◽  
Ze Jun Wen
Keyword(s):  
Energy Transfer ◽  
Network Topology ◽  
Interaction Model ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Gear Train ◽  
Power Losses ◽  
Planetary Gear Train ◽  
Conservation Of Energy ◽  
Transfer Equations

A model for the transmission efficiency of the planetary gear train has been proposed based on the principle of energy. The network topology for the planetary gear train is established with the graph theory by substitution the net nodes for the parts. According to the principle of conservation of energy, the interaction model of the energy transfer of the gear train is built by the way of integration the energy transfer equations between the nodes. With the investigation on the power losses, the transmission efficiency of planetary gear train can be calculated.

Automatic Detection of Embedded Structure in Planetary Gear Trains

1997 ◽  
Vol 119 (2) ◽  
pp. 315-318 ◽  
Author(s):  
Cheng-Ho Hsu ◽  
Yi-Chang Wu
Keyword(s):  
Computer Program ◽  
Automatic Detection ◽  
Planetary Gear ◽  
Gear Train ◽  
Graph Representation ◽  
Structural Synthesis ◽  
Planetary Gear Train ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
Embedded Structure

The detection of embedded structure is one of important steps in the structural synthesis of planetary gear trains. The purpose of this paper is to develop a computer program for the automatic detection of embedded structure in planetary gear trains. First, the graph representation of a planetary gear train is used to clarify the kinematic structure. Next, the concept of fundamental circuit is applied to derive an algorithm for the detection of embedded structure in a planetary gear train. Using the notation of adjacency matrix, an interactive computer program has been developed such that embedded structure in a planetary gear train can be automatically analyzed by only entering the corresponding graph.

The Detection of Embedded Structure in Planetary Gear Trains

1996 ◽  
Author(s):  
Cheng-Ho Hsu ◽  
Jin-Juh Hsu ◽  
Yi-Chang Wu
Keyword(s):  
Computer Program ◽  
Planetary Gear ◽  
Gear Train ◽  
Graph Representation ◽  
Structural Synthesis ◽  
Planetary Gear Train ◽  
Interactive Computer Program ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
Embedded Structure

Abstract The detection of embedded structure is one of important steps in the structural synthesis of planetary gear trains. The purpose of this paper is to develop a computer program for the automatic detection of embedded structure in planetary gear trains. First, the graph representation of planetary gear trains are used to clarify the kinematic structure. Next, a method which is based on the concept of fundamental circuits for the detection of embedded structure in a planetary gear train. Using the notation of adjacency matrix, an interactive computer program has been developed such that embedded structure in a planetary gear train can be automatically analyzed by only entering the corresponding graph.

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