Development of the Sphere-Toroidal Continuously Variable Transmission

2014 ◽  
Vol 986-987 ◽  
pp. 1315-1318
Author(s):  
Shun Min Wang ◽  
Zhuo Li ◽  
Xin Yu Wang ◽  
Xi Chao Li

This paper describes a new genre of Toroidal-CVT system, called the Sphere-Toroidal Continuously Variable Transmission (STCVT), which is derived from the half-toroidal traction drive (TCVT) and introduces its structure and working principle. The torque transfers from the input shaft to the cross-axle universal shaft coupling connected with the driven shaft. By discussing the difference between the torque-transfer, the paper will show the possibility of the application in the vehicle. To conclude, the system has the potential to implement infinite extension for the CVT theoretically.

2005 ◽  
Vol 127 (1) ◽  
pp. 114-119 ◽  
Author(s):  
O. S. Cretu ◽  
R. P. Glovnea

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.


2010 ◽  
Vol 37-38 ◽  
pp. 1489-1492
Author(s):  
Chuan Qiong Sun ◽  
Guo Xing Sun ◽  
Ai Hua Ren ◽  
Yong De Liu

Based on the research of non-circular gear Continuously Variable Transmission (CVT), firstly the working principle of the heart-shaped gear is introduced, and then the kinematic characteristics are analyzed, lastly the feature of the heart-shaped gear CVT is obtained.


Author(s):  
Songho Kim ◽  
Michael Peshkin ◽  
J. Edward Colgate

Rotational CVTs (continuously varible transmissions) constrain the velocities of two rotational joints to a computer-controlled ratio. CVTs traction drive mechanisms that rely on the support of traction forces across rolling contracts. When called upon to transmit loads, CVTs produce a velocity ratio that departs from the ideal transmission ratio. This paper reports on the results of our analysis in pursuit of understanding the mechanics of the rotational CVT. We present the measured velocity ratios in the face of lateral loads at various transmission settings. In addition, wer present our model that closely fits the empirical data.


2011 ◽  
Vol 317-319 ◽  
pp. 529-532
Author(s):  
Kei Lin Kuo

Compared to conventional transmission layouts, Active continuously variable transmission (CVT) provides smoother gear shifting and gear ratio in smaller increments, and is, therefore, more accommodating the needs of both the driver and passengers. A few notable improvements are enhanced passenger comfort, higher transmission efficiency, and improved acceleration. Incorporating all of the above qualities has become a major developmental focus for the automotive industry, and the potential for improvement warrants further investigation. A CVT controls the gear ratio by changing the diameters of the primary (input) and the secondary (output) pulleys by adjusting the hydraulic pressure applied to each using valves. Hydraulic pressure in the channel is developed using a basic pump connected to the input shaft. Excess pressure produced at higher speed is wasted. This study aims to minimize this hydraulic pressure without affecting the transmission’s performance, in order to conserve energy. A user interface was set up and the CVT’s torque converter was modified such that the inner and outer shafts could be operated independently, allowing for full control of hydraulic pressure .This experiment successfully achieved, via a custom LabVIEW program, its goal of controlling the gear ratio between the primary and secondary pulleys whilst operating at lower pressures to those specified by the manufacturer. This proves that it is possible to fully control the CVT whilst operating at a reduced hydraulic pressure.


2011 ◽  
Vol 328-330 ◽  
pp. 360-363
Author(s):  
Ai Hua Ren ◽  
Guo Xing Sun ◽  
Chuan Qiong Sun

Though spatial cam has been widely used in various fields of machinery and equipment ,but it is seldom used in continuously variable transmission situation. So firstly the working principle of spatial cam for CVT is introduced, and then equations of the pitch curve and cam contour are derived .In order to get the required dimensions and parameters of spatial cam during three dimensional modeling, program is developed with programming software Mathcad and the corresponding programming flow chart is listed out. And the running results of the Mathcad program and features of spatial cam in Pro/E are correlated to realize solid modeling, at last an example is given to demonstrate the feasibility and flexiblity of this method.


2018 ◽  
Vol 226 ◽  
pp. 01012 ◽  
Author(s):  
Alexander A. Prikhodko

Stirred tanks are used in many industries to intensify various physical and chemical processes. Currently, one of the most promising areas of research is the creation of rotationally reciprocating stirred tanks (RRST), which realize high mixing efficiency due to the difference in the velocities of the stirred liquid. As the actuator of RRST, we proposed to use a planetary gear with elliptical gears. Due to the variable transmission ratio of elliptical gearwheels, the rotationally reciprocating motion of the output shaft is ensured with rotational motion of the input shaft. We conducted a structural analysis of the planetary gear by means of the structural mathematical model of mechanisms and machines. A kinematic model of planetary gear has been constructed and studied, resulting in velocity analogue function of the mechanism output shaft.


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