A New Constant Velocity Coupling

1977 ◽  
Vol 99 (2) ◽  
pp. 367-372 ◽  
Author(s):  
V. Milenkovic
Keyword(s):  
Constant Velocity ◽  
Velocity Ratio ◽  
Kinematic Model ◽  
Formal Proof

A constant velocity coupling has been developed that does not resemble any coupling built before. It was intended for a specialized application, with specifications that are outside the range of any existing designs. A kinematic model as well as a subscale prototype have been constructed, and the latter was successfully tested. The principles of the coupling are discussed in some detail, with emphasis on their kinematic aspects. The formal proof for the constancy of the velocity ratio of this coupling is presented.

Characteristics of a co-flowing jet with varying lip thickness and constant velocity ratio

2020 ◽  
Vol 92 (4) ◽  
pp. 633-644
Author(s):  
Naren Shankar R. ◽  
Kevin Bennett S. ◽  
Dilip Raja N. ◽  
Sathish Kumar K.
Keyword(s):  
Constant Velocity ◽  
Velocity Ratio ◽  
Critical Limit ◽  
Potential Core ◽  
Content Type ◽  
Free Jet ◽  
Current Scenario ◽  
Wake Zone ◽  
Bypass Ratio ◽  
Practical Implications

Purpose This study aims to analyze co-flowing jets (CFJs) with constant velocity ratio (VR) and varying primary nozzle lip thickness (LT) to find a critical LT in CFJs below which mixing enhances and beyond which mixing inhibits. Design/methodology/approach CFJs were characterized with a constant VR and varying LTs. A single free jet with a diameter equal to that of a primary nozzle of the CFJ was used for characteristic comparison. Numerical simulation is carried out and is validated with the experimental results. Findings The results show that within a critical limit, the mixing enhanced with an increase in LT. This was signified by a reduction in potential core length (PCL). Beyond this limit, mixing inhibited leading to the elongation of PCL. This limit was controlled by parameters such as LT and constant VR. A new region termed as influential wake zone is identified. Practical implications In this study, the VR is maintained constant and bypass ratio (BR) was varied from low value to very high values. Presently, subsonic commercial turbo fan operates under low to ultra-high BR. Hence the present study becomes vital to the current scenario. Originality/value To the best of the authors’ knowledge, this is the first effort to find the critical value of LT for a constant VR for compressible co-flow jets. The CFJs with constant VR and varying LT have not been studied in the past. The present study focuses on finding a critical LT below which mixing enhances and above which mixing inhibits.

Displacement Analysis of Spatial 7R Mechanisms Suitable for Constant-Velocity Transmission Between Parallel Shafts

1979 ◽  
Vol 101 (4) ◽  
pp. 604-613 ◽  
Author(s):  
M. J. Gilmartin ◽  
J. Duffy
Keyword(s):  
Constant Velocity ◽  
Velocity Ratio ◽  
Numerical Results ◽  
Theory Method ◽  
Unified Theory ◽  
Displacement Analysis ◽  
Loop Method ◽  
Joint Coupling ◽  
Velocity Transmission ◽  
Special Case

Three types of spatial 7R mechanisms are identified as being suitable for transmitting motion with a constant velocity ratio between two parallel shafts. A displacement analysis of each type is made using a vector loop method in conjunction with the Unified Theory method. Numerical results are presented for an example of each type. It is also shown how the double Hooke joint coupling for parallel shafts is a special case of one of these three types.

Algebraic Method for Exact Synthesis of 1-DOF Linkages With Arbitrarily Prescribed Constant Velocity Ratios

2021 ◽  
pp. 1-18
Author(s):  
Kai Liu ◽  
Jingjun Yu
Keyword(s):  
Constant Velocity ◽  
High Speed ◽  
Characteristic Curve ◽  
Velocity Ratio ◽  
Algebraic Approach ◽  
Algebraic Method ◽  
Angular Motion ◽  
Open Chain ◽  
Pure Rolling ◽  
Spherical Linkages

Abstract This paper addresses the synthesis of 1-DOF linkages that can exactly transmit angular motion between coplanar axes (i.e. parallel axes or intersectant axes) with arbitrarily prescribed constant velocity ratios. According to motion polynomials over dual quaternions and pure rolling models between two circles, an algebraic approach is presented to precisely synthesize new 1-DOF linkages with arbitrarily prescribed constant velocity ratios. The approach includes four steps: (a) formulate a characteristic curve occurred by the pure rolling, (b) compute the motion polynomial of the minimal degree that can generate the curve, (c) deal with the factorization of the motion polynomial to construct an open chain, (d) convert the open chain to a 1-DOF linkage. Using this approach, several 1-DOF planar, spherical, and spatial linkages for angular motion transmission between parallel axes or intersectant ones are constructed by designating various velocity ratios. Taking the planar and spherical linkages with a constant 1:2 velocity ratio as examples, kinematics analysis is implemented to prove their motion characteristics. The result shows that the generated linkages indeed can transmit angular motion between two coplanar axes with constant velocity ratios. Meanwhile, 3D-printed prototypes of these linkages also demonstrate such a conclusion. This work provides a framework for synthesizing linkages that have great application potential to transmit motion in robotic systems that require low inertia to achieve reciprocating motion with high speed and accuracy.

Inverted Slider Crank, Coupled in Tandem to Another Four Bar, to Generate a Constant Velocity Ratio

1969 ◽  
Vol 91 (1) ◽  
pp. 37-44
Author(s):  
W. Meyer zur Capellen
Keyword(s):  
Constant Velocity ◽  
Velocity Ratio ◽  
Planetary Gear ◽  
Function Generators ◽  
Scotch Yoke Mechanism

Combinations of the inverted slider-crank linkage (i.e., the Whitworth quick-return mechanism) with another of the same sort, with a scotch-yoke mechanism or with a planetary gear, are able to produce excellent function generators having a stationary value of velocity ratio. Various forms are discussed, and graphs of their characteristic motions are shown.

On the Necessary and Sufficient Conditions for Homokinetic Transmission in Chains of Cardan Joints

1993 ◽  
Vol 115 (2) ◽  
pp. 255-261 ◽  
Author(s):  
D. A. Johnson ◽  
P. Y. Willems
Keyword(s):  
Constant Velocity ◽  
Velocity Ratio ◽  
Sufficient Conditions ◽  
Point Of View ◽  
Necessary And Sufficient Conditions ◽  
Flexible Design ◽  
Universal Joint ◽  
Necessary And Sufficient ◽  
Ratio Transmission

The classical double universal joint for constant velocity ratio transmission is subject to strict geometrical requirements as regards configuration, and it is generally accepted that similar constraints also prevail for longer chains of joints. This paper examines the constant velocity conditions from a necessary point of view and establishes new configuration possibilities for chains of 3 or more joints, which allow to envisage more flexible design in some applications.

Record Wear Studies by Scanning Electron Microscopy

1968 ◽  
Vol 26 ◽  
pp. 364-365
Author(s):  
M.D. Coutts ◽  
E.R. Levin ◽  
J.G. Woodward
Keyword(s):  
Electron Microscopy ◽  
Constant Velocity ◽  
Peak Velocity ◽  
Great Depth ◽  
Depth Of Focus ◽  
Sweep Frequency ◽  
Transmission Electron ◽  
Test Record ◽  
Lateral Mode ◽  
Scanning Electron

While record grooves have been studied by transmission electron microscopy with replica techniques, and by optical microscopy, the former are cumbersome and restricted and the latter limited by lack of depth of focus and resolution at higher magnification. With its great depth of focus and ease in specimen manipulation, the scanning electron microscope is admirably suited for record wear studies.A special RCA sweep frequency test record was used with both lateral and vertical modulation bands. The signal is a repetitive, constant-velocity sweep from 2 to 20 kHz having a duration and repetitive rate of approximately 0.1 sec. and a peak velocity of 5.5 cm/s.A series of different pickups and numbers of plays were used on vinyl records. One centimeter discs were then cut out, mounted and coated with 200 Å of gold to prevent charging during examination. Wear studies were made by taking micrographs of record grooves having 1, 10 and 50 plays with each stylus and comparing with typical “no-play” grooves. Fig. 1 shows unplayed grooves in a vinyl pressing with sweep-frequency modulation in the lateral mode.

Type Theory and Formal Proof

2009 ◽  
Author(s):  
Rob Nederpelt ◽  
Herman Geuvers
Keyword(s):  
Type Theory ◽  
Formal Proof

Numerical analysis and explore of asymmetrical fluid flow in a two-sided lid-driven cavity

2020 ◽  
Vol 14 (3) ◽  
pp. 7269-7281
Author(s):  
El Amin Azzouz ◽  
Samir Houat
Keyword(s):  
Velocity Ratio ◽  
Two Dimensional ◽  
Lower Side ◽  
Square Cavity ◽  
Driven Cavity ◽  
Parallel Motion ◽  
Bottom Cavity ◽  
Secondary Vortices ◽  
Volume Method ◽  
Fluid Characteristics

The two-dimensional asymmetrical flow in a two-sided lid-driven square cavity is numerically analyzed by the finite volume method (FVM). The top and bottom walls slide in parallel and antiparallel motions with various velocity ratio (UT/Ub=λ) where |λ|=2, 4, 8, and 10. In this study, the Reynolds number Re1 = 200, 400, 800 and 1000 is applied for the upper side and Re2 = 100 constant on the lower side. The numerical results are presented in terms of streamlines, vorticity contours and velocity profiles. These results reveal the effect of varying the velocity ratio and consequently the Reynolds ratio on the flow behaviour and fluid characteristics inside the cavity. Unlike conventional symmetrical driven flows, asymmetrical flow patterns and velocity distributions distinct the bulk of the cavity with the rising Reynolds ratio. For λ>2, in addition to the main vortex, the parallel motion of the walls induces two secondary vortices near the bottom cavity corners. however, the antiparallel motion generates two secondary vortices on the bottom right corner. The parallel flow proves affected considerably compared to the antiparallel flow.

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