scholarly journals Effect of the Radial Dimension of the Driver Sheet on the Electromagnetic Driven Forming

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 133503-133513
Author(s):  
Lantao Huang ◽  
Zinan Ding ◽  
Yihan Zhou ◽  
Jin Zeng ◽  
Jiahao Zou
Keyword(s):  
Radial Dimension ◽  
Driver Sheet

scholarly journals Elastic hydrodynamic lubrication analysis for a sine movable tooth drive

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881410 ◽  
Author(s):  
Lizhong Xu ◽  
Wentao Song
Keyword(s):  
Film Thickness ◽  
Hydrodynamic Lubrication ◽  
Normal Operation ◽  
Speed Ratio ◽  
Input Shaft ◽  
Load Carrying ◽  
Radial Dimension ◽  
Lubrication Condition ◽  
Shaft Rotation Angle ◽  
Large Speed

The sine movable tooth drive has small radial dimension such that the heat, caused by friction, becomes an important factor in deciding its load-carrying ability. It is important to determine the amount of tooth lubrication in order to reduce the heat caused by the friction. This study provides equations for the meshing performance and provides the forces for the sine movable tooth drive. Using these equations, the minimum oil film thickness for the drive system is investigated. Results show that the minimum film thickness between the movable tooth and input shaft or shell changes periodically along the input shaft rotation angle. A large movable tooth radius and a movable tooth rotation radius could increase the film thickness between the movable tooth and the input shaft or the shell. In addition, a large speed ratio could increase the film thickness between the movable tooth and the input shaft, but this would also decrease the film thickness between the movable tooth and the shell. A large sine amplitude could increase the film thickness between the movable tooth and the input shaft, but this does not change the film thickness between the movable tooth and the shell. Under normal operation speeds, the hydrodynamic lubrication condition occurs between the movable tooth and the input shaft, and the partial membrane hydrodynamic state occurs between the movable tooth and the shell.

Study on the Large Range Torque Transmitter Quickly Assembled Used for the Calibration of Hydraulic Tongs

2015 ◽  
Vol 741 ◽  
pp. 582-585
Author(s):  
Xiang Tong Yang ◽  
Fu Xiang Zhang ◽  
Xiao Yu ◽  
Yang Yu ◽  
Yi Hua Dou
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Measurement Accuracy ◽  
Large Range ◽  
Oil Field ◽  
Strain Gages ◽  
Radial Dimension

For oil field, Square surface connection embedded in our torque transmitter are designed to connect 2 torsion rods instead of flanges, which can shorten the radial dimension of the large range torque transmitter, and realizes the rapid assembly in oil field. It is the chemical composition of elastomer that determines the mechanical properties of the elastomer; the paste process of strain gages will affect the parameters of the torque transmitter, such as linearity, measurement accuracy, hysteresis, repeatability etc.

Analysis of mechanical errors in disc cam mechanisms

2005 ◽  
Vol 219 (2) ◽  
pp. 209-224 ◽  
Author(s):  
L-I Wu ◽  
W-T Chang
Keyword(s):  
Exact Solution ◽  
Analytical Method ◽  
Sudden Change ◽  
Design Parameters ◽  
Combined Effects ◽  
Worst Case ◽  
Cam Mechanism ◽  
Radial Dimension ◽  
Cam Profile ◽  
Shift Angle

This paper presents an analytical method for analysing the mechanical errors of disc cam mechanisms. With the aid of parametric expressions of the cam profile and by employing the concept of equivalent linkage, the error of the follower motion that is due to the variation in each design parameter can be determined analytically. The resulting error equations do not really involve the location of the curvature centre of the cam profile, and thus locating the curvature centre of the cam profile is not essential. The method is validated through analysing a cam mechanism that has an invariant equivalent linkage, and thus an exact solution is available. Compared with the exact solutions, the predicted results have at least four-figure accuracy. For the roller follower cases, the pressure angle has most effect on the resulting error. Owing to the counteraction of the shift angle, the resulting error due to the radial dimension error of the cam profile has relatively smaller variation. In the worst case, owing to the combined effects of various design parameters, the accuracy of the follower motion may degrade considerably. The acceleration error functions have a sudden change at the ends of the motion.

scholarly journals Twist-driven separation of p-type and n-type dopants in single-crystalline nanowires

2019 ◽  
Vol 6 (3) ◽  
pp. 532-539 ◽  
Author(s):  
Dong-Bo Zhang ◽  
Xing-Ju Zhao ◽  
Gotthard Seifert ◽  
Kinfai Tse ◽  
Junyi Zhu
Keyword(s):  
Shear Strain ◽  
Radial Distribution ◽  
Atomistic Simulations ◽  
Si Nanowires ◽  
Modulation Doping ◽  
Single Crystalline ◽  
Host Atom ◽  
Homogeneous Materials ◽  
Radial Dimension ◽  
P Type

The distribution of dopants significantly influences the properties of semiconductors, yet effective modulation and separation of p-type and n-type dopants in homogeneous materials remain challenging, especially for nanostructures. Employing a bond orbital model with supportive atomistic simulations, we show that axial twisting can substantially modulate the radial distribution of dopants in Si nanowires (NWs) such that dopants of smaller sizes than the host atom prefer atomic sites near the NW core, while dopants of larger sizes are prone to staying adjacent to the NW surface. We attribute such distinct behaviors to the twist-induced inhomogeneous shear strain in NW. With this, our investigation on codoping pairs further reveals that with proper choices of codoping pairs, e.g. B and Sb, n-type and p-type dopants can be well separated along the NW radial dimension. Our findings suggest that twisting may lead to realizations of p–n junction configuration and modulation doping in single-crystalline NWs.

scholarly journals Chromospheric Surface Structures on EI Eridani and HD 199178

1991 ◽  
Vol 130 ◽  
pp. 330-332
Author(s):  
James E. Neff
Keyword(s):  
Spatial Distribution ◽  
Effective Temperature ◽  
Three Dimensional ◽  
Stellar Atmospheres ◽  
Surface Structures ◽  
High Dispersion ◽  
The Sun ◽  
Late Type ◽  
Magnetic Topology ◽  
Radial Dimension

Several groups at this meeting are presenting maps of the spatial distribution of either brightness or effective temperature in the photospheres of rapidly-rotating, late-type stars. It is generally believed that structure seen in these maps traces the magnetic topology, in analogy with the Sun. We expect the structure of the outer atmospheres (i.e., chromosphere and corona) of these stars to be even more directly tied to the magnetic topology; the magnetic structure is three-dimensional. In order to probe the radial dimension of stellar atmospheres, we need to combine maps of the spatial distribution of emission from chromospheres and coronae with these detailed photospheric maps.Along with collaborators at Armagh, Catania, Boulder, Paris, Helsinki, and Stony Brook, I have been obtaining high-dispersion ultraviolet spectra of several rapidly-rotating, late-type stars using the IUE spacecraft. I discuss results for two stars, El Eridani and HD 199178, for which photospheric maps are presented elsewhere at this conference.

Seismic‐while‐drilling by using tunnel boring machine noise

Geophysics ◽  
2002 ◽  
Vol 67 (6) ◽  
pp. 1798-1809 ◽  
Author(s):  
Lorenzo Petronio ◽  
Flavio Poletto
Keyword(s):  
Large Diameter ◽  
Tunnel Boring Machine ◽  
High Amplitude ◽  
Direct Access ◽  
S Wave ◽  
Tunnel Excavation ◽  
Tunnel Boring ◽  
Cutting Head ◽  
Geothermal Wells ◽  
Radial Dimension

The tunnel boring machine (TBM) is used extensively to mechanically excavate tunnels. To optimize the mechanical drilling and work safely, an estimate of the geology to be drilled is necessary. We consider using the elastic waves produced by the TBM cutting wheel to obtain seismic‐while‐drilling (SWD) information for predicting the geology ahead of the drilling front. This method uses accelerometers mounted on the TBM together with geophones located along and outside the tunnel, similar to the technique successfully used to drill oil and geothermal wells. Study of noise and the resolution of the signal produced by the large‐diameter cutting head shows that nonstationary noise separation can be achieved by locating sensors at the front and rear ends of the tunnel. The (higher) resolution in front of the TBM is limited by pilot delays, while the (lower) lateral resolution is limited by the radial dimension of the TBM. Analysis of seismic data acquired in a field test shows that P‐ and S‐wave arrivals have a wide frequency band and high amplitude in seismic traces measured 700 m away from the drilling front. In comparison with SWD applications in wells, tunnel SWD technology has the advantage of allowing direct access to the tunnel front, which makes it easy to connect the TBM reference sensors for while‐drilling monitoring. This method can be successfully applied without interfering with drilling activity to monitor tunnel excavation continuously, reduce risks, and optimize drilling.

Research on pipeline elbow passing for in-pipe robot

2011 ◽  
Vol 226 (5) ◽  
pp. 1382-1394 ◽  
Author(s):  
J W Qiao ◽  
J Z Shang
Keyword(s):  
Detailed Analysis ◽  
Whole Process ◽  
Matlab Program ◽  
Structural Variables ◽  
Calculation Results ◽  
Radial Dimension ◽  
Inspection And Maintenance ◽  
Pass Through

In-pipe robots provide inspection and maintenance services to various pipelines. This article proposes an algorithm to calculate the required radial variations for in-pipe robots to pass through pipeline elbows smoothly. It first gives a full overview of a robot passing through a U-shaped elbow and identifies the problem location where the radial dimension changes the most. It then presents a detailed analysis on the focused stage and deduces the algorithm. Based on the obtained algorithm, a realizing Matlab program is written to calculate all possible lengths of front and rear legs at every moment during the process. Finally, the calculation results are presented to precisely describe the track of movement, the length deformations during the whole process, and different contributions of structural variables. This article provides the design and the control of an in-pipe robot with an algorithm to calculate the lengths of its legs at every moment and to what extent the deformations of elastic legs are required.

scholarly journals Characterization of convergent thickening, a major convergence force producing morphogenic movement in amphibians

2018 ◽  
Author(s):  
David Shook ◽  
Jason Wen ◽  
Ana Rolo ◽  
Brian Francica ◽  
Destiny Dobins ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Surface Area ◽  
Marginal Zone ◽  
Tensile Force ◽  
African Clawed Frog ◽  
Radial Dimension ◽  
Morphogenic Process ◽  
Clawed Frog

SUMMARYWe characterize the morphogenic process of convergent thickening (CT), which occurs in the involuting marginal zone (IMZ) during gastrulation of Xenopus, the African clawed frog. CT was described previously as the tendency of explants of the ventral IMZ of Xenopus to converge their circumblastoporal dimension and thicken their radial dimension (Keller and Danilchik 1988). Here we show that CT occurs from the onset of gastrulation, initially throughout the pre-involution IMZ. We suggest that CT is driven by an increase in the interfacial tension between the deep IMZ and its epithelium, resulting in cells of the deep IMZ tending to minimize their surface area. In explants, this results in a progressive shortening (convergence) of the IMZ along its longer mediolateral axis and thickening in the orthogonal planes, and can generate tensile force (Shook et al. 2018). In vivo, convergence of the annular IMZ generates circumferential tension, closing the blastopore. These results provide the first clear example of a tensile morphogenic force from a Holtfreterian/Steinbergian change in tissue affinity.

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