Design and Analysis of a Spherical Continuously Variable Transmission

2000 ◽  
Vol 124 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Jungyun Kim ◽  
F. C. Park ◽  
Yeongil Park ◽  
Mishima Shizuo
Keyword(s):  
Energy Efficiency ◽  
Mobile Robots ◽  
Contact Point ◽  
Power Source ◽  
Continuously Variable Transmission ◽  
Small Scale ◽  
Simple Design ◽  
Axis Of Rotation ◽  
Input And Output ◽  
Variable Transmission

In this article we propose the design of a novel continuously variable transmission, the spherical continuously variable transmission (S-CVT). The S-CVT consists of a sphere, input and output discs, and variators. The rotating input and output discs are connected to the power source and output shafts, respectively, while the sphere is situated between the input and output discs. The transmission ratio is controlled by adjusting the location of the contact point between the variators and the sphere, which in turn controls the axis of rotation of the sphere. The S-CVT can smoothly transit between the forward, neutral, and reverse states without any brakes or clutches, and its compact and simple design and its relatively simple control make it particularly effective for mechanical systems in which excessively large torques are not required (e.g., mobile robots, household appliances, small-scale machining centers). We describe the operating principles behind the S-CVT, including a kinematic and dynamic analysis. Simulations and experiments with a constructed prototype are conducted to assess the performance of the S-CVT, including a study of its energy efficiency vis-a´-vis reduction gears.

Constant Power Continuously Variable Transmission (CP-CVT): Operating Principle and Analysis

2005 ◽  
Vol 127 (1) ◽  
pp. 114-119 ◽  
Author(s):  
O. S. Cretu ◽  
R. P. Glovnea
Keyword(s):  
Automobile Industry ◽  
Rotation Axis ◽  
Continuously Variable Transmission ◽  
Constant Power ◽  
Traction Drive ◽  
Power Characteristics ◽  
Input And Output ◽  
Output Torque ◽  
Variable Transmission ◽  
Toroidal Traction

The paper is the first of a series of papers that present an original constant power continuously variable transmission (CP-CVT) traction drive. This paper presents the basic functional principle and demonstrates the device’s characteristics of constant power. The device belongs to the well-known toroidal traction drive family. It comprises of two input discs, one conical and the other toroidal, a conical output disc, and a number of spherical balls. The rotation axis of each ball is self-adjusted according to its geometrical position relative to the input and output discs. A variation of the output torque makes the balls change their position relative to the discs and thus causes a change of the transmission ratio. The kinematics and dynamics of the balls are first performed and then the formulas that relate the power transmitted to the kinematics and geometric parameters are deducted. Finally it is concluded that the CP-CVT presented offers good functional steady power characteristics that could fit the automobile industry requirements.

scholarly journals Proposing a Method for Assessing Fuel Consumption and Pollutants Emissions with the Use of Continuously Variable Transmission in Town Cars

2021 ◽  
Vol 4 (4) ◽  
pp. 134-140
Author(s):  
Leonardo Serfert Junior ◽  
Thiago B. Muraria ◽  
Lilian Lefol Nani Guarieiro
Keyword(s):  
Energy Efficiency ◽  
Fuel Consumption ◽  
Sustainable Development Goals ◽  
Automatic Transmission ◽  
Continuously Variable Transmission ◽  
The Sustainable Development ◽  
General Government ◽  
Variable Transmission ◽  
Consumption Energy ◽  
Development Goals

The 21st century brings countless social, economic, environmental, and technological challenges to humanity and, to face them, the United Nations (UN) created the Sustainable Development Goals (SDGs). The auto industry, which is part of the private sector, aims to reach them. In this context, this study aims to evaluate the consumption and emissions of pollutants by using an automatic transmission of the CVT (Continuously Variable Transmission) type concerning the automatic transmission of the "Planetary" type. This study will be based on the Consumption/Energy Efficiency tables, published annually by INMETRO (National Institute of Metrology, Quality, and Technology) and whose data will be processed and evaluated using the Quik Sense Software. Thus, the work aims to appraise the advantages of vehicles with automatic transmission of the CVT type about fuel consumption, energy efficiency and emissions, in markets such as Brazil, where these vehicles use ethanol or a mixture of gasoline with up to 27 as fuel % Ethanol. This research can contribute to studies of emission control and approval, benefiting the automotive industry in general, government agencies, the environment, the economy, and society, contributing to the UN's SDGs achievement.

scholarly journals Effects of Electric Circulation on the Energy Efficiency of the Power Split e-CVT Hybrid Systems

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2342 ◽  
Author(s):  
Cheng-Ta Chung ◽  
Chien-Hsun Wu ◽  
Yi-Hsuan Hung
Keyword(s):  
Energy Efficiency ◽  
Hybrid Systems ◽  
High Speed ◽  
Electric Energy ◽  
Continuously Variable Transmission ◽  
Operating Characteristics ◽  
Power Split ◽  
Variable Transmission ◽  
And Control ◽  
Operating Points

This paper aims at investigating the fundamental characteristics of energy efficiency for power split electronic-continuously-variable-transmission (e-CVT) hybrid systems under the operation of electric circulation, i.e., circulating part of the engine power through the generator and motor in form of electric energy to improve system efficiency as well as perform the continuously-variable-transmission (CVT) functionality. The relations of kinematics and energy conservation for each power component are constructed and analyzed to classify how the operating points of the engine in term of torque and rotational speed may vary under different degrees of electric circulation indicated by a parameter called ratio of circulating power. Thereby, power split e-CVT hybrid systems can be classified into three types: upward circulation, downward circulation, and neutral circulation. Accordingly, two power split e-CVT hybrid systems, one of input split type and the other of output split type, are selected to be analyzed regarding their operating characteristics and simulated on their performances of energy efficiency. As a result, the former is a type of downward circulation in favor of driving at low speed and high driving load, while the latter is a type of upward circulation with an advantage of driving at high speed and low driving load. Thereby, applying this analysis to investigate the effects of electric circulation on power split e-CVT systems may help the developers implement suitable energy management and control strategy in accordance with their corresponding operating characteristics of energy efficiency.

scholarly journals Experimental Investigation on Floating Solar-Driven Membrane Distillation Desalination Modules

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 304
Author(s):  
Qingxiu Miao ◽  
Yaoling Zhang ◽  
Shuo Cong ◽  
Fei Guo
Keyword(s):  
Power Source ◽  
Membrane Distillation ◽  
Small Scale ◽  
Sea Waves ◽  
Permeate Flux ◽  
Practical Application ◽  
Rejection Ratio ◽  
Cold Source ◽  
Mild Temperature ◽  
Feed Temperature

Membrane distillation (MD) processes need a relatively mild temperature gradient as the driving force for desalination. In the field, it is reasonable to utilize solar energy as the heat source for the feed, and seawater as the infinite cold source for condensation. Solar-driven MD provides a route for the practical application of seawater desalination at a small scale. In this work, we focus on floating MD modules with a solar heating bag as the power source, and perform proof-of-principle experiments on the MD performance under various conditioning parameters, including feed flow rate, feed temperature, salinity, air gap, and sea waves. The results indicate that floating solar-driven MD modules are feasible in terms of permeate flux and salt rejection ratio, and the upward evaporation MD configuration leads to a better performance in terms of permeate flux. The simulation and experiments also show that the natural sea waves disturb the heating bag and the MD module floating on the surface of seawater, and effectively enhance the feed circulation and transport in the system.

scholarly journals Triggering avalanches by transverse perturbations in a rotating drum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vicente Salinas ◽  
Cristóbal Quiñinao ◽  
Sebastián González ◽  
Gustavo Castillo
Keyword(s):  
Hopf Bifurcation ◽  
Theoretical Model ◽  
Order Parameter ◽  
Small Scale ◽  
Rotating Drum ◽  
Governing Parameter ◽  
Stick Slip ◽  
Slip Regime ◽  
Axis Of Rotation

AbstractWe study the role of small-scale perturbations in the onset of avalanches in a rotating drum in the stick-slip regime. By vibrating the system along the axis of rotation with an amplitude orders of magnitude smaller than the particles’ diameter, we found that the order parameter that properly describes the system is the kinetic energy. We also show that, for high enough frequencies, the onset of the avalanche is determined by the amplitude of the oscillation, contrary to previous studies that showed that either acceleration or velocity was the governing parameter. Finally, we present a theoretical model that explains the transition between the continuous and discrete avalanche regimes as a supercritical Hopf bifurcation.

Sign in / Sign up

Export Citation Format

Share Document