Traction and Efficiency Performance of the Double Roller Full-Toroidal Variator: A Comparison With Half- and Full-Toroidal Drives

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
L. De Novellis ◽  
G. Carbone ◽  
L. Mangialardi
Keyword(s):  
Mechanical Efficiency ◽  
The Other ◽  
Classical Solutions ◽  
Speed Ratio ◽  
Traction Drive ◽  
Torque Transmission ◽  
Wide Range ◽  
Efficiency Performance ◽  
Unit Speed ◽  
Toroidal Traction

In this paper, we analyze in terms of efficiency and traction capabilities a recently patented toroidal traction drive variator: the so-called double roller full-toroidal variator (DFTV). By employing a relatively simple model of the elastohydrodynamic contact behavior between the disks and rollers, we compare the performance of the DFTV with classical solutions as the single-roller full-toroidal variator (SFTV) and the single-roller half-toroidal variator (SHTV). Interestingly, the DFTV shows an improvement of the mechanical efficiency over a wide range of transmission ratios, and in particular at the unit speed ratio, as in such conditions the DFTV allows for zero-spin thus strongly enhancing its traction capabilities. The relation between the torque transmission and the operational volume is also investigated for the three toroid geometries. In this case, the better performance is achieved by the SHTV, whereas the other two geometries show a similar behavior.

scholarly journals Mechanical Hybrid KERS Based on Toroidal Traction Drives: An Example of Smart Tribological Design to Improve Terrestrial Vehicle Performance

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Francesco Bottiglione ◽  
Giuseppe Carbone ◽  
Leonardo De Novellis ◽  
Luigi Mangialardi ◽  
Giacomo Mantriota
Keyword(s):  
Energy Recovery ◽  
Elastohydrodynamic Lubrication ◽  
Mechanical Efficiency ◽  
Speed Ratio ◽  
Vehicle Performance ◽  
Lubrication Regimes ◽  
Recovery Potential ◽  
Wide Range ◽  
Unit Speed ◽  
Traction Drives

We analyse in terms of efficiency and traction capabilities a recently patented traction drive, referred to as the double roller full-toroidal variator (DFTV). We compare its performance with the single roller full-toroidal variator (SFTV) and the single roller half-toroidal variator (SHTV). Modeling of these variators involves challenging tribological issues; the traction and efficiency performances depend on tribological phenomena occurring at the interface between rollers and disks, where the lubricant undergoes very severe elastohydrodynamic lubrication regimes. Interestingly, the DFTV shows an improvement of the mechanical efficiency over a wide range of transmission ratios and in particular at the unit speed ratio as in such conditions in which the DFTV allows for zero-spin, thus strongly enhancing its traction capabilities. The very high mechanical efficiency and traction performances of the DFTV are exploited to investigate the performance of a flywheel-based Kinetic Energy Recovery System (KERS), where the efficiency of the variator plays an important role in determining the overall energy recovery performance. The energy boost capabilities and the round-trip efficiency are calculated for the three different variators considered in this study. The results suggest that the energy recovery potential of the mechanical KERS can be improved with a proper choice of the variator.

Electro-Hydraulic Digital Control of Cone-Roller Toroidal Traction Drive Automatic Power Transmission

1984 ◽  
Vol 106 (4) ◽  
pp. 305-310 ◽  
Author(s):  
H. Tanaka ◽  
T. Ishihara
Keyword(s):  
Power Transmission ◽  
Computer Control ◽  
Speed Ratio ◽  
Test Results ◽  
Optimum Conditions ◽  
Propulsion Systems ◽  
Traction Drive ◽  
Automatic Transmissions ◽  
Optimum Speed ◽  
Toroidal Traction

Continuously variable automatic transmissions can bring improved fuel economy benefits under good speed ratio changes for automobile propulsion systems in which engines can produce their power under optimum conditions. These systems require computer control for the calculation of optimum speed ratio. The paper presents design features of the electrohydraulic interface between micro-computer and cone-roller toroidal traction drive CVT, dynamic characteristics of cone roller motion, and test results of the practical computer control of CVT.

2D Color-Intensity Representation of Ultrasonic Thickness Gauge Measurements

2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong
Keyword(s):  
Cost Effective ◽  
The Other ◽  
Thickness Gauge ◽  
Color Intensity ◽  
Digital Readout ◽  
Flat Surfaces ◽  
Video Cameras ◽  
Wide Range ◽  
Cost Effective Alternative ◽  
Ultrasonic Thickness

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.

p-Sulfonic acid calix[n]arene catalyzed synthesis of bioactive heterocycles: A review

2020 ◽  
Vol 24 ◽  
Author(s):  
Bubun Banerjee ◽  
Gurpreet Kaur ◽  
Navdeep Kaur
Keyword(s):  
Supramolecular Chemistry ◽  
Sulfonic Acid ◽  
Catalytic Efficiency ◽  
The Other ◽  
Reaction Conditions ◽  
Metal Free ◽  
Bioactive Scaffolds ◽  
Wide Range ◽  
Efficient Alternative ◽  
Bioactive Heterocycles

: Metal-free organocatalysts are becoming an important tool for the sustainable developments of various bioactive heterocycles. On the other hand, during last two decades, calix[n]arenes have been gaining considerable attention due to their wide range of applicability in the field of supramolecular chemistry. Recently, sulfonic acid functionalized calix[n] arenes are being employed as an efficient alternative catalyst for the synthesis of various bioactive scaffolds. In this review we have summarized the catalytic efficiency of p-sulfonic acid calix[n]arenes for the synthesis of diverse biologically promising scaffolds under various reaction conditions. There is no such review available in the literature showing the catalytic applicability of p-sulfonic acid calix[n]arenes. Therefore, we strongly believe that this review will surely attract those researchers who are interested about this fascinating organocatalyst.

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