Design, Modeling, and Simulation of a Geared Infinitely Variable Transmission

2014 ◽  
Vol 136 (7) ◽  
Author(s):  
X. F. Wang ◽  
W. D. Zhu
Keyword(s):  
Planetary Gear ◽  
Speed Ratio ◽  
Start Up ◽  
Continuous Output ◽  
Direction Control ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Planetary Gear Sets ◽  
Working Principle ◽  
Crank Length

An infinitely variable transmission (IVT) to provide a continuous output-to-input speed ratio from zero to a certain value is designed, and its working principle is illustrated. It is a geared IVT (GIVT), since its function to achieve the continuously varied speed ratio is implemented by gears. Crank-slider systems are used in the GIVT; the output-to-input speed ratio is changed with the crank length. Racks and pinions, whose motion is controlled by planetary gear sets, are used to change the crank length when the cranks rotate. One-way bearings are used to rectify output speeds from different crank-slider systems to obtain the output speed of the GIVT. Since the crank-slider systems can introduce variations of the instantaneous speed ratio, a pair of noncircular gears is designed to minimize the variations. A direction control system is also designed for the GIVT using planetary gear sets. Finally, a vehicle start-up simulation and a wind turbine simulation to maintain a constant generator speed are developed based on a GIVT module in the Matlab Simulink environment.

Design, Modeling, and Experimental Validation of a Novel Infinitely Variable Transmission Based on Scotch Yoke Systems

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
X. F. Wang ◽  
W. D. Zhu
Keyword(s):  
Planetary Gear ◽  
Speed Ratio ◽  
Control Module ◽  
Kinematic Behavior ◽  
Input Control ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Planetary Gear Sets ◽  
Noncircular Gears ◽  
Crank Length

A novel infinitely variable transmission (IVT) based on scotch yoke systems is designed to provide a continuously varied output-to-input speed ratio from zero to a specified value. By changing the crank length of scotch yoke systems, the speed ratio of the IVT can be continuously adjusted. The IVT consists of a pair of noncircular gears and two modules: an input-control module and a motion conversion module. The input-control module employs two planetary gear sets to combine the input speed of the IVT with the control speed from the stepper motor that changes the crank length of scotch yoke systems. The motion conversion module employs two scotch yoke systems to convert the combined speeds from the input-control module to translational speeds of yokes, and the translational speeds are converted to output speeds through rack–pinions. The speed ratio between the output of the motion conversion module and the input of the input-control module has a shape of a sinusoidal-like wave, which generates instantaneous variations. Use of scotch yoke systems provides a benefit to isolate the interaction between the crank length and the shape of the speed ratio, and a pair of noncircular gears can be used to eliminate the instantaneous variations of the speed ratio for all crank lengths. A prototype of the IVT was built and instrumented, and its kinematic behavior was experimentally validated. A driving test was conducted to examine the performance of the IVT.

Dynamic Analysis of a Novel Geared Infinitely Variable Transmission

2014 ◽  
Author(s):  
Z. R. Li ◽  
X. F. Wang ◽  
W. D. Zhu
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbine ◽  
Speed Ratio ◽  
Lagrangian Dynamics ◽  
Input And Output ◽  
Newtonian Dynamics ◽  
Continuous Output ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Crank Length

A novel geared infinitely variable transmission (IVT) that can generate a continuous output-to-input speed ratio from zero to a certain value is studied for vehicle and wind turbine applications. The principle of changing the output-to-input speed ratio is to use a crank-slider mechanism; the output-to-input speed ratio is controlled by adjusting the crank length. Since the crank-slider mechanism can lead to relatively large variation of the output-to-input speed ratio in one rotation of the crank, the instantaneous input and output speeds and accelerations have variations and the corresponding forces exerted on each part of the IVT can have obvious changes in one rotation of the crank. Since forces on some parts of the IVT are critical and can cause failure of the IVT, a dynamic analysis of the IVT is necessary to simulate the input and output speeds and accelerations. A method that combines Lagrangian dynamics and Newtonian dynamics is developed in this work to analyze the motion of the IVT. The dynamic analysis results can be used to evaluate the design of the IVT.

Dynamic Analysis of a Geared Infinitely Variable Transmission

2016 ◽  
Vol 12 (3) ◽  
Author(s):  
X. F. Wang ◽  
Z. R. Li ◽  
W. D. Zhu
Keyword(s):  
Dynamic Analysis ◽  
Speed Ratio ◽  
Force Analysis ◽  
Maximum Torque ◽  
Input Shaft ◽  
Continuous Output ◽  
Input Side ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Output Side

Dynamic analysis of a geared infinitely variable transmission (IVT) that can generate a continuous output-to-input speed ratio from zero to a certain value is studied for vehicle and wind turbine applications. With the IVT considered as a multirigid-body system, the Lagrangian approach is used to analyze its speeds and accelerations, and the Newtonian approach is used to conduct force analysis of each part of the IVT. Instantaneous input and output speeds and accelerations of the IVT have variations in one rotation of its input shaft. This work shows that the instantaneous input speed has less variation than the instantaneous output speed when the inertia on the input side is larger than that on the output side and vice versa. The maximum torque on the output shaft that is a critical part of the IVT increases with the input speed.

Contact Stress Reduction Mechanisms for the CAM-Based Infinitely Variable Transmission

2007 ◽  
Author(s):  
Derek F. Lahr ◽  
Dennis W. Hong
Keyword(s):  
Contact Stress ◽  
Stress Reduction ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Speed Ratio ◽  
Cam Mechanism ◽  
Expected Performance ◽  
Differential Mechanism ◽  
Variable Transmission ◽  
Infinitely Variable Transmission

The Cam-based Infinitely Variable Transmission (IVT) is a new type of ratcheting IVT based on a three dimensional cam and follower system which provides unique characteristics such as generating specific functional speed ratio outputs including dwells, for a constant velocity input. This paper presents several mechanisms and design approaches used to improve the torque and speed capacity of this unique transmission. A compact, lightweight, and capable differential mechanism based on a cord and pulley system is developed to double the number of followers in contact with the cam at any time, thereby reducing the contact stress between the followers and the cam surface considerably. A kinematic model governing the motion of this differential is developed and a few experimental results from the prototype are presented, showing an overall increase in performance including a smooth output, a wide gear range, and the ability to shift under load. Plans for future improvements to the design, including an inverted external cam mechanism, is also presented along with the expected performance gains.

Design of a Series-Type Independently Controllable Transmission Mechanism

2012 ◽  
Author(s):  
Guan-Shyong Hwang ◽  
Der-Min Tsay ◽  
Jao-Hwa Kuang ◽  
Tzuen-Lih Chern ◽  
Tsu-Chi Kuo
Keyword(s):  
Angular Velocity ◽  
Planetary Gear ◽  
Transmission Mechanism ◽  
Alternative Form ◽  
Input Shaft ◽  
Planetary Gear Trains ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Gear Trains ◽  
Series Type

This study proposes a design of transmission mechanism which is referred to as a series-type independently controllable transmission (ICT). The series-type ICT is an alternative form of the parallel-types proposed in the former researches. The series-type ICT can serve as a continuously or an infinitely variable transmission mechanism, and it can also produce a required angular output velocity that can be independently manipulated by a controller and not affected by the angular velocity of the input shaft. The series-type ICT mechanism is composed of two planetary gear trains and two transmission-connecting members. Kinematic and dynamic characteristics of the ICT mechanism are analyzed and their analytical equations are derived for application in this study.

A Positively-Engaged Infinitely Variable Transmission Using Split Helical Gears

2018 ◽  
Author(s):  
Ethan R. Brush ◽  
Carl A. Nelson
Keyword(s):  
Angular Velocity ◽  
Electric Vehicles ◽  
Gear Ratio ◽  
Helical Gears ◽  
Continuously Variable Transmissions ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
New Type ◽  
Working Principle

Continuously variable transmissions (CVTs), and the subset known as infinitely variable transmissions (IVTs) with gear ratio ranges reaching zero (0:1 or 1:∞ or “geared neutral”), offer motors the ability to run in preferred angular velocity ranges independent of transmission output speed, allowing optimization for power, torque, and efficiency. This paper presents and analyzes a positively engaged IVT (PE-IVT) mechanism of an entirely new type and working principle which solves the problems of current CVTs and is applicable to the unique requirements of robots, electric vehicles (EVs), and hybridelectric vehicles (HEVs).

Adaption of Continuously Variable Transmissions to the Characteristic of a Driven Machine by Bicoupled Planetary Transmissions

1981 ◽  
Vol 103 (1) ◽  
pp. 41-47
Author(s):  
H. W. Mu¨ller
Keyword(s):  
Planetary Gear ◽  
Output Characteristic ◽  
Speed Ratio ◽  
Continuously Variable Transmissions ◽  
Variable Transmission ◽  
Standardized Method ◽  
Ratio Range

Bicoupled Planetary Transmissions composed of any variable Transmission and a planetary gear can be designed to realize any optional speed ratio range including speed reversal and its output characteristic can be approached to the characteristic of the driven machine in order to obtain an economic overall transmission. The paper describes a standardized method to design and to optimize such transmissions.

The Transmission Performances of Traction Infinitely Variable Transmission Used in Electric Vehicle Power Train

2012 ◽  
Vol 271-272 ◽  
pp. 1239-1243
Author(s):  
Fen Zhu Ji ◽  
Hao Hua Du
Keyword(s):  
Basic Structure ◽  
Transmission Efficiency ◽  
Transmission Characteristics ◽  
Power Train ◽  
Pure Rolling ◽  
Adams Software ◽  
Calculation Results ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Working Principle

The traction infinitely variable transmission (TIVT) used in the power train of electric vehicles (EVS) was designed. Firstly, based on the analysis of basic structure and working principle, the mathematic models were established on the transmission ratio, slipping ratio, transferring torsion and transmission efficiency; Secondly, Transmission characteristics of the TIVT were analyzed and calculated using ADAMS software. The calculation results show that: the export torsion varies with sway angle of steer ring as the import torsion is fixed. The transmission efficiency of TIVT is large when the motion of driving parts is pure-rolling or the slipping ratio is less. The efficiency could be reached more than 99% by rational designing. Theoretically, the driving distance of EVS matched with TIVT could be increased.

Study of a Non-Circular Gear Infinitely Variable Transmission

2014 ◽  
Author(s):  
Kumar Hebbale ◽  
Dongxu Li ◽  
Jing Zhou ◽  
Chengwu Duan ◽  
Chi-Kuan Kao ◽  
...  
Keyword(s):  
Static Analysis ◽  
Fuel Efficiency ◽  
Planetary Gear ◽  
Gear Ratio ◽  
Development Effort ◽  
Function Generator ◽  
Multiple Function ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Function Generators

Improving automobile fuel efficiency is an important research and development effort in the automotive industry. In the transmission area, it is generally understood that optimum fuel economy can be achieved via a combination of highly efficient power transfer (gears, for example) and an ability to transmit power at an infinite number of ratios (CVT, for example). In this paper, a geared infinitely variable transmission (IVT) is analyzed for efficiency through static analysis. This IVT is based on a non-circular gear concept described in [1, 2]. This IVT consists of multiple function generators with each function generator comprising two sets of non-circular gear sets whose outputs are combined with a summing planetary gear set. Each function generator provides the desired gear ratio for only a part of the driving rotation. So, multiple function generators are combined along with multiple one-way clutches to provide an infinitely variable transmission. This paper first explains the operating principle of the geared IVT. A static analysis of the IVT powerflow is derived and it is shown that this powerflow exhibits a torque recirculation phenomenon, which is not desired. This recirculation phenomenon is expected to be present in all similarly arranged IVTs where two inputs are combined using a planetary gear set to provide infinite gear ratio capability. The efficiency of the IVT is calculated based on assumed individual component efficiency and it is shown that, owing to torque recirculation, the efficiency of this transmission may not compare well with that of current automatic transmissions for a passenger car application.

scholarly journals Infinitely variable transmission with orbital pulleys

2019 ◽  
Vol 11 (10) ◽  
pp. 168781401988371
Author(s):  
Hector Cervantes-Culebro ◽  
Carlos Alberto Cruz-Villar ◽  
Orlando Palma-Marrufo
Keyword(s):  
Dynamic Model ◽  
Planetary Gear ◽  
The Other ◽  
Parallel Transmission ◽  
Translational Movement ◽  
Proposed Model ◽  
Variable Transmission ◽  
Infinitely Variable Transmission ◽  
Fixed Constant ◽  
Orbital Pulley

The purpose of this article is to propose an infinite variable transmission with orbital pulleys, which consists of two parallel transmission systems. The system comprises a planetary gear set and a continuously variable transmission. The principle of operation of the infinite variable transmission proposed in this article is based on the actuation of one half-sided pulley, which has a translational movement in a direction, and the same amount of movement is reproduced by the other half-sided orbital pulley in reverse to secure that the length of the belt remains constant. The fixed constant horizon enables the infinite variable transmission to change the transmission ratio from negative values to positive passing through zero in a continuous manner without using a clutch or interrupting the system. The dynamic model and prototype of the infinite variable transmission with orbital pulleys are developed for designing, controlling, and validating purposes. The model is obtained using the Euler–Lagrange methodology, and it is experimentally validated by comparing the proposed model with the experimental measures. The infinite variable transmission with orbital pulleys is controlled under different conditions; the experimental results show that the proposed design of infinite variable transmission provides robustness to maintain constant speeds at the output to changes at the input velocity.

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