Digital measurements of the shaft rotation angle and the phase shift by the conversion of each parameter into a pair of dc voltages

1998 ◽  
Vol 41 (2) ◽  
pp. 140-146
Author(s):  
V. B. Ibragimov
Keyword(s):  
Phase Shift ◽  
Rotation Angle ◽  
Shaft Rotation ◽  
Digital Measurements ◽  
Shaft Rotation Angle

scholarly journals Influence of Water and Mineral Oil on the Leaks in Satellite Motor Commutation Unit Clearances

2017 ◽  
Vol 24 (3) ◽  
pp. 58-67 ◽  
Author(s):  
Paweł Śliwiński
Keyword(s):  
Rotation Angle ◽  
Mineral Oil ◽  
Fluid Viscosity ◽  
Working Chamber ◽  
Shaft Rotation ◽  
Influence Of Water ◽  
Mathematical Formulas ◽  
Working Media ◽  
Shaft Rotation Angle ◽  
Geometrical Dimensions

Abstract The article describes the flow rates of mineral oil and water flowing, as working media, through the commutation unit of a hydraulic satellite motor. It is demonstrated that geometrical dimensions of commutation unit clearances change as a function of the machine shaft rotation angle. Methods for measuring the rate of this flow and the pressure in the working chamber are presented. The results of pressure measurements in the working chamber during the transition from the filling cycle to the emptying cycle are included. The pressure in the motor’s working chamber changes linearly as a function of the shaft rotation angle, which has a significant effect on the leakage in the commutation unit clearances. The paper presents new mathematical formulas in the form: Q=f(Δpγ) to calculate the flow rate of water and mineral oil in the commutation unit clearances. The γ factor is described as a function of fluid viscosity and clearance length (the motor shaft rotation angle). The coefficients used in these formulas were determined based on the results of laboratory tests of a motor supplied with water and mineral oil.

scholarly journals Study of the press forming mechanism of a thermoforming machine

2013 ◽  
Vol 228 (10) ◽  
pp. 1715-1723 ◽  
Author(s):  
Guido Belforte ◽  
Federico Colombo ◽  
Terenziano Raparelli ◽  
Daniela Maffiodo
Keyword(s):  
Rotation Angle ◽  
Equations Of Motion ◽  
Numerical Code ◽  
Internal Stresses ◽  
Motor Shaft ◽  
Forming Mechanism ◽  
Press Forming ◽  
The Press ◽  
Parametric Studies ◽  
Shaft Rotation Angle

The paper presents kinematic and dynamic investigations of the main press forming mechanism of a thermoforming machine. A multibody analysis of this press forming mechanism, which lifts and rotates a press bed, was carried out. Press bed lifting, which is necessary to form the component, is performed by means of a first rod and toggle mechanism. Press bed rotation to eject the formed component is produced by means of a second rod and must be appropriately shifted. These rods are oscillating followers driven by cams, making it possible to precisely define trajectories as a function of the motor shaft rotation angle. Analysis is performed by numerically solving the equations of motion. Cam synthesis on the basis of the oscillating followers’ trajectories makes it possible to obtain cam profiles in order to evaluate pressure angles and check that there is no undercutting. System dynamics is investigated in order to evaluate motor torque and analyse internal stresses on the hinges. In addition, some experimental results and those obtained with the dynamic model are compared. Performance improvement of the actual machine is carried out by modifying the trajectory of the press bed by means of a numerical code at the purpose developed. This approach is more convenient than the use of a commercial multibody code, which is not specifically built for parametric studies.

Dynamic Model and Numerical Simulation for Synchronal Rotary Compressor

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Hui Zhou ◽  
Zongchang Qu ◽  
Hua Yang ◽  
Bingfeng Yu
Keyword(s):  
Relative Velocity ◽  
Rotation Angle ◽  
Structural Characteristics ◽  
Side Surface ◽  
Mechanical Efficiency ◽  
The Other ◽  
Rotary Compressor ◽  
Working Principle ◽  
Shaft Rotation Angle ◽  
Average Relative Velocity

The synchronal rotary compressor (SRC) has been developed to resolve high friction and severe wear that usually occur in conventional rotary compressors due to the high relative velocity between the key tribo-pairs. In this study, the working principle and structural characteristics of the SRC are presented first. Then, the kinematic and force models are established for the key components—cylinder, sliding vane, and rotor. The velocity, acceleration, and force equations with shaft rotation angle are derived for each component. Based on the established models, numerical simulations are performed for a SRC prototype. Moreover, experiments are conducted to verify the established models. The simulated results show that the average relative velocity between the rotor and the cylinder of the present compressor decreases by 80–82% compared with that of the conventional rotary compressors with the same size and operating parameters. Moreover, the average relative velocity between the sliding contact tribo-pairs of the SRC decreases by 93–94.3% compared with that of the conventional rotary compressors. In addition, the simulated results show that the stresses on the sliding vane are greater than those on the other components. The experimental results indicate that the wear of the side surface of the sliding vane is more severe than that of the other components. Therefore, special treatments are needed for the sliding vane in order to improve its reliability. These findings confirm that the new SRC has lower frictional losses and higher mechanical efficiency for its advanced structure and working principle.

Object Wave Determination by Single-Sideband Methods

1973 ◽  
Vol 31 ◽  
pp. 266-267
Author(s):  
Kenneth H. Downing ◽  
Benjamin M. Siegel
Keyword(s):  
Phase Shift ◽  
Carbon Films ◽  
Object Wave ◽  
Electron Wave ◽  
Phase Object ◽  
Heavy Atoms ◽  
Single Sideband ◽  
Thin Carbon ◽  
Additional Phase Shift ◽  
Additional Phase

Under the “weak phase object” approximation, the component of the electron wave scattered by an object is phase shifted by π/2 with respect to the unscattered component. This phase shift has been confirmed for thin carbon films by many experiments dealing with image contrast and the contrast transfer theory. There is also an additional phase shift which is a function of the atomic number of the scattering atom. This shift is negligible for light atoms such as carbon, but becomes significant for heavy atoms as used for stains for biological specimens. The light elements are imaged as phase objects, while those atoms scattering with a larger phase shift may be imaged as amplitude objects. There is a great deal of interest in determining the complete object wave, i.e., both the phase and amplitude components of the electron wave leaving the object.

A Many-Beam Technique for Enhanced Resolution of Partial Dislocations

1972 ◽  
Vol 30 ◽  
pp. 646-647
Author(s):  
J. M. Oblak ◽  
B. H. Kear
Keyword(s):  
Phase Shift ◽  
Field Method ◽  
Dark Field ◽  
Bright Field ◽  
Field Technique ◽  
Weak Beam ◽  
Partial Dislocations ◽  
Enhanced Resolution ◽  
Nickel Base ◽  
Beam Technique

The “weak-beam” and systematic many-beam techniques are the currently available methods for resolution of closely spaced dislocations or other inhomogeneities imaged through strain contrast. The former is a dark field technique and image intensities are usually very weak. The latter is a bright field technique, but generally use of a high voltage instrument is required. In what follows a bright field method for obtaining enhanced resolution of partial dislocations at 100 KV accelerating potential will be described.A brief discussion of an application will first be given. A study of intermediate temperature creep processes in commercial nickel-base alloys strengthened by the Ll2 Ni3 Al γ precipitate has suggested that partial dislocations such as those labelled 1 and 2 in Fig. 1(a) are in reality composed of two closely spaced a/6 <112> Shockley partials. Stacking fault contrast, when present, tends to obscure resolution of the partials; thus, conditions for resolution must be chosen such that the phase shift at the fault is 0 or a multiple of 2π.

Structure and migration of planar defects in crystals observed in atomic scale

1978 ◽  
Vol 36 (1) ◽  
pp. 284-285 ◽  
Author(s):  
H. Hashimoto ◽  
Y. Sugimoto ◽  
Y. Takai ◽  
H. Endoh
Keyword(s):  
Electron Microscope ◽  
Rotation Angle ◽  
Crystal Surface ◽  
Electron Gun ◽  
Atomic Scale ◽  
Present Observation ◽  
Twist Boundary ◽  
Optical Magnification ◽  
Zinc Crystal ◽  
And Migration

As was demonstrated by the present authors that atomic structure of simple crystal can be photographed by the conventional 100 kV electron microscope adjusted at “aberration free focus (AFF)” condition. In order to operate the microscope at AFF condition effectively, highly stabilized electron beams with small energy spread and small beam divergence are necessary. In the present observation, a 120 kV electron microscope with LaB6 electron gun was used. The most of the images were taken with the direct electron optical magnification of 1.3 million times and then magnified photographically.1. Twist boundary of ZnSFig. 1 is the image of wurtzite single crystal with twist boundary grown on the surface of zinc crystal by the reaction of sulphur vapour of 1540 Torr at 500°C. Crystal surface is parallel to (00.1) plane and electron beam is incident along the axis normal to the crystal surface. In the twist boundary there is a dislocation net work between two perfect crystals with a certain rotation angle.

Observation of surface morphology by reflection electron holography

1989 ◽  
Vol 47 ◽  
pp. 536-537
Author(s):  
N. Osakabe ◽  
J. Endo ◽  
T. Matsuda ◽  
A. Tonomura
Keyword(s):  
Phase Shift ◽  
Surface Morphology ◽  
High Sensitivity ◽  
High Energy ◽  
Path Difference ◽  
Transmission Mode ◽  
Electron Holography ◽  
Dynamical Process ◽  
High Vertical Resolution ◽  
Amplification Technique

Progress in microscopy such as STM and TEM-TED has revealed surface structures in atomic dimension. REM has been used for the observation of surface dynamical process and surface morphology. Recently developed reflection electron holography, which employes REM optics to measure the phase shift of reflected electron, has been proved to be effective for the observation of surface morphology in high vertical resolution ≃ 0.01 Å.The key to the high sensitivity of the method is best shown by comparing the phase shift generation by surface topography with that in transmission mode. Difference in refractive index between vacuum and material Vo/2E≃10-4 owes the phase shift in transmission mode as shownn Fig. 1( a). While geometrical path difference is created in reflection mode( Fig. 1(b) ), which is measured interferometrically using high energy electron beam of wavelength ≃0.01 Å. Together with the phase amplification technique , the vertivcal resolution is expected to be ≤0.01 Å in an ideal case.

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