scholarly journals A Mathematical Method for Eliminating Spin Losses in Toroidal Traction Drives

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Qingtao Li ◽  
Jie Wu ◽  
Hua Li ◽  
Jin Yao
Keyword(s):  
Cone Angle ◽  
Transmission Ratio ◽  
Geometrical Parameters ◽  
Speed Distribution ◽  
Working Surface ◽  
Variable Transmission ◽  
Traction Drives ◽  
Toroidal Traction ◽  
Half Cone ◽  
Ratio Range

The efficiency of the original Toroidal continuously variable transmission (CVT) is limited due to the spin losses caused by the different speed distribution in the contact area. To overcome this drawback, this paper replaces the original working surface with a new surface derived from a differential equation and proposes a novel Logarithmic CVT. Equations and ranges of the transmission ratio range, half-cone-angle, and conformity ratio, which are essential geometrical parameters of the Logarithmic CVT, are derived. A set of geometrical parameters is further recommended. With such geometrical parameters, the transmission ratio range of the Logarithmic CVT is as wide as that of the Half-Toroidal CVT. The two types of CVTs are compared with each other in terms of efficiency based on a widely accepted computational model. The results show that efficiency of the Logarithmic CVT is higher than that of Half-Toroidal CVT except for some particular situations because of the thrust bearing losses.

Design and simulation of a steering gearbox with variable transmission ratio

2012 ◽  
Vol 226 (10) ◽  
pp. 2538-2548 ◽  
Author(s):  
Petre Alexandru ◽  
Dragoş Macaveiu ◽  
Cătălin Alexandru
Keyword(s):  
Steering System ◽  
Transmission Ratio ◽  
Geometrical Parameters ◽  
Electric Power Steering ◽  
Hydraulic Power ◽  
Power Steering ◽  
Variable Transmission ◽  
Involute Gears ◽  
Safe Control ◽  
Hydraulic Power Steering

This article presents the geometric and functional characteristics of a steering gearbox with variable transmission ratio, which contains a translating wheel (circular curved rack) in gearing with an eccentric sector (segment). The solution requires no special technology because it uses conventional involute gears, being obtained/derived from a classic gearbox with constant ratio by changing the gearing characteristics. The precision of the steering system and the reversibility of the gearing are not affected by these modifications, the driver having a good/safe control of the vehicle. This gearbox can be used for the steering systems of some low-power vehicles, assuring an increased actuating torque (less effort); in this way, the assistance (hydraulic power steering or electric power steering) can be avoided. The study is focused on the following objectives: formulating the theoretical bases, establishing the geometrical parameters, and simulating the functionality of the gearbox, based on the specific requirements of the vehicles’ steering system. Important conclusions have been drawn on the influence of some specific parameters in terms of insuring good gearing conditions, such as the variation of the distances between axes and the variation of the clearance between teeth.

scholarly journals The method for synthesis of the contact ratio of noncircular bevel gears

2021 ◽  
Vol 12 (1) ◽  
pp. 165-172
Author(s):  
Kan Shi ◽  
Shuai Lin ◽  
Yan'an Yao
Keyword(s):  
Transmission Ratio ◽  
Polar Coordinate System ◽  
Contact Ratio ◽  
Bevel Gears ◽  
Innovative Methods ◽  
Ratio Curve ◽  
Pure Rolling ◽  
Variable Transmission ◽  
Polar Coordinate ◽  
Pitch Curve

Abstract. As a type of spatial transmission mechanism, noncircular bevel gears can be used to transfer the power and motion with a variable transmission ratio between intersecting axes. In this paper, utilizing the spherical triangle theorem and meshing principle, the parametric equations of the contact ratio are established in the space polar coordinate system. Two innovative methods are proposed to analyze the contact ratio by using the rotation angle of the driving (driven) gears and the arc length of pitch curve as pure rolling. In the case of modified gear and X-zero gear, whether the noncircular bevel gear is continuously driven is deduced. The simulation transmission ratio curve and theoretical transmission ratio curve are compared to verify the rationality of the design.

Numerical Investigation of the Effect of Capsule Half-Cone Angle on a Supersonic Parachute System

2016 ◽  
Vol 29 (4) ◽  
pp. 06016001 ◽  
Author(s):  
Xiao-Peng Xue ◽  
Yusuke Nishiyama ◽  
Yoshiaki Nakamura ◽  
Koichi Mori ◽  
Chih-Yung Wen
Keyword(s):  
Numerical Investigation ◽  
Cone Angle ◽  
Parachute System ◽  
Half Cone ◽  
Half Cone Angle

Comparison of Two Complete Solutions in an Axisymmetric Extrusion With Experiment

1969 ◽  
Vol 91 (3) ◽  
pp. 543-548 ◽  
Author(s):  
A. H. Shabaik ◽  
E. G. Thomsen
Keyword(s):  
Strain Rate ◽  
Effective Strain ◽  
Cone Angle ◽  
Low Friction ◽  
First Approximation ◽  
Strain And Strain Rate ◽  
Conical Die ◽  
Stream Lines ◽  
Half Cone ◽  
Half Cone Angle

An upper-bound and a potential solution to a forward extrusion problem were compared with experimental results obtained by the visioplasticity method. The process consisted of extruding a 2-in-dia billet of preforged lead through a conical die having a half-cone angle of 45 deg under the condition of relatively low friction. The comparison was made for steady state stream lines, velocities, strain rate components, effective strain and strain rate, grid distortion, and stress distribution. It was found that the curves were generally of similar shape and that some differences existed in magnitude only. It is suggested that the theoretical solutions can be used to advantage to a first approximation in predicting all important variables.

scholarly journals Development technique for deep drawing without blank holder to produce circular cup of brass alloy

2015 ◽  
Vol 4 (1) ◽  
pp. 187 ◽  
Author(s):  
Ali Hassan Saleh ◽  
Ammer Khalaf Ali
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Deep Drawing ◽  
Cone Angle ◽  
Element Model ◽  
Drawing Ratio ◽  
Clearance Ratio ◽  
Blank Holder ◽  
Half Cone ◽  
Half Cone Angle

Of this technique compared to the conventional deep drawing is that the circular cup can be carried out in single action press with limit In this paper a new mechanism for deep drawing was proposed to produce circular cup from thin plate without blank holder. In this technique the die assembly includes punch, die and die-punch. A 2D axisymmetric finite element model was built using DEFORM software. Effect of die geometry (half- cone angle) on maximum load, thickness distribution, strain distribution and effect of clearance ratio between punch and (die-punch) on the wrinkling of the cup were investigated. Three half-cone angles of die (15o, 30o and 45o) were used for forming sheet metal of brass (CuZn37) which had initial thickness of (1mm) at four clearance ratio (c/t) for die of 30o half-cone angle. Finite element model results showed good agreement with experimental results. Die of 30o half-cone angle with clearance ratio (c/t) of 0.9 gave the best product without wrinkling. The main advantage drawing ratio (LDR) of 1.86 and blank diameter to blank thickness ratio (d/t) < 86.

scholarly journals Experimental Investigation of the Performance and Spray Characteristics of a Supersonic Two-Phase Flow Ejector with Different Structures

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1166 ◽  
Author(s):  
Shizhen Li ◽  
Wei Li ◽  
Yanjun Liu ◽  
Chen Ji ◽  
Jingzhi Zhang
Keyword(s):  
High Speed ◽  
Two Phase Flow ◽  
Fire Suppression ◽  
Cone Angle ◽  
Water Mist ◽  
Pulsation Period ◽  
Phase Flow ◽  
Two Phase ◽  
Half Cone ◽  
Half Cone Angle

A two-phase flow ejector is an important part of a water mist fire suppression system, and these devices have become a popular research topic in recent years. This paper proposes a supersonic ejector that aims to improve the efficiency of water mist fire suppression systems. The effects of ejector geometric parameters on the entrainment ratio (ER) were explored. The effects of primary flow pressure (PP) on the mixing process and flow phenomena were studied by a high-speed camera. The experimental results show that the ER first increases and then decreases with increasing PP. ER increases with increasing ejector area ratio (AR). The PP corresponding to the maximum ER of ejectors with a different nozzle exit position (NXP) is 3.6 bar. The ejector with an NXP of +1 and AR of 6 demonstrate the best performance, and the ER of this ejector reaches 36.29. The spray half-cone angle of the ejector increases with increasing ER, reaching a maximum value of 7.07°. The unstable atomization half-cone angle is mainly due to a two-phase flow pulsating phenomenon. The pulsation period is 10 ms. In the present study, a general rule that provides a reference for ejector design and selection was obtained through experiments.

Sampling of High-Quality Wet Steam from Steam Mains Operating at 11·4 Bar Pressure

1973 ◽  
Vol 187 (1) ◽  
pp. 381-393 ◽  
Author(s):  
D. J. Ryley ◽  
M. J. Holmes
Keyword(s):  
Static Pressure ◽  
Water Mass ◽  
Cone Angle ◽  
Wet Steam ◽  
High Quality ◽  
Flow Rates ◽  
Further Development ◽  
Half Cone ◽  
Steam Main ◽  
Half Cone Angle

A venturi device was employed to strip and entrain liquid from the wall of a 3 in (7·5 cm) diameter steam main prior to isokinetic sampling. By injecting heated water into dry steam the wetness fraction was controlled between 1 and 5 per cent. Venturi convergence half-cone angles of 20, 30, 40 and 50° were employed and steam flow rates varied from 360–730 kg/h (800–1600 1b/h). Observations were made of the distribution through the test section of static pressure, recovered temperature and film thickness (for pressure 3·8 bar (55 1b/in2 absolute) only). Sampling across a diameter showed that under the most advantageous conditions the ratio, aggregate mass of entrained water: mass of injected water did not exceed 23 per cent. The optimum venturi half-cone angle lay between 40 and 50°. While capable of further development, the stripping-sampling principle seems unlikely to lead to significant improvements in wet steam sampling for quality.

Simulation of New Wet Duster’s Nozzle Based on Fluent

2014 ◽  
Vol 556-562 ◽  
pp. 1133-1135
Author(s):  
Shan Shan Tang ◽  
Kai Song Wang ◽  
Chao Kun Wei ◽  
Teng Fei Ma
Keyword(s):  
3D Model ◽  
Water Pressure ◽  
Cone Angle ◽  
Wind Pressure ◽  
Safety Hazard ◽  
Field Simulation ◽  
Working Surface ◽  
Potential Safety ◽  
Normal Work ◽  
Nozzle Structure

Overweight of dust concentration is a common problem happened in most coal mine that not only affects workers’ normal work ,but also brings a great potential safety hazard to mine.New wet duster’ operating principle is that wind pressure and water pressure which generated in working surface pipeline network go through the nozzle jet and produce negative pressure leading the dust into dust catching pipe, and then the dust removed.According to optimizing the nozzle structure can increase spray’s cone Angle inside the shower nozzle,then the dust removal ability will be improved.The paper built the nozzle’ 3D model and the water’ the river basin model in SolidWorks ,then meshed them in Gambit and finally analysis the pressure and nozzle size’s influence on fluid’s pressure and velocity with Fluent’s flow field simulation.

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