Rotary Parts Research Articles

Study on Ultrasonic P-Scan Imaging Technology for Rotary Parts Used in Coal Mine Machinery

Aiming at implementing numeralization, automatization and imaging of ultrasonic testing in rotary parts used in coal mine machinery, ultrasonic P-scan imaging technology of rotary parts is studied in this paper. Searching pixel units according to the incident direction of ultrasonic, and correcting non-isotropic resolution images to isotropic ones with linear interpolation algorithm to, multi-layer B-/C-/D-scan and 3-D projection view imaging are achieved. Experimental results show P-scan image could accurately reflect the localization, quantification and orientation of flaws.

Development of Ultrasonic Automatic Testing System for Flaws of Rotary Parts

In order to conquer the disadvantages of undetection, misjudgment and low-efficiency in ultrasonic A-scan testing for rotary parts, an ultrasonic automatic imaging system was developed, and automatic scan device was specially designed for rotary parts. Moreover, the testing software was programmed by LabWindows/CVI, which achieves the acquisition and processing of ultrasonic signals, and displays A, B, C, D and P-scan image. On the basis of storing A-scan data and transforming non-isotropic resolution B-scan image into isotropic one, P-scan imaging is realized. Medium filtering was applied to A-scan signal and C-scan image and the Signal-to-Noise is improved. The experimental results show that this system has well achieved numeralization, automatization and imaging of ultrasonic testing.

Numerical Computation of Dynamic Character Coefficient of Journal Bearing

The purpose of this study is to determine the dynamic character coefficient of journal bearing with the consideration of bearing load direction and oil groove. Based on numerical differential method, the oil film pressure distribution on journal bearing is obtained with the point-by-point relaxation iteration method. Then, the dynamic characters are calculated by numerical integral algorithm.The calculation program is developed for the dynamic characteristics of journal bearing. The computation method provides a useful guide for the numerical simulation of rotary parts.

Research on vehicle rotary parts vibration by multi-sensor data fusion

Research on vehicle rotary parts vibration by multi-sensor data fusion

3D FE Modeling of Three Rolls Cross Rolling Process of a Rotary Disk Part

Special rolling is also called rotary forming process, which is an advanced manufacture technology of making workpiece generate deformation in a rotary state by continuous local plastic forming. Disk rotary parts with outer stepped cross-section, such as wheels, flanges, valves and so on, are widely used in engineering machinery. Traditionally, this kind of part is manufactured by forging and cutting, which consumes a lot of energy and materials especially to the large size part. In this paper, a new specific rolling technique called three rolls cross rolling is first presented to produce this kind of part, and the principle and characteristics of this technique are described in detail. Then, base on the principle of the three rolls cross rolling, a 3D coupled thermo-mechanical FE model is developed under ABAQUS software environment. As a result, under the simulation and analyses of a real example, the feasibility of this technique is verified, and the evolutional laws of the strain, temperature and rolling force and power parameters during the process are investigated as well. The obtained results provide valuable guidelines for the further investigation on the forming characteristic of the three rolls cross rolling technique.

Hybrid backup power supply for telecommunication systems based on fuel cell

Telecommunication network nodes located at very hostile environments require, among other rigorous demands, highly reliable backup power supplies. Current solutions, which are mostly based on diesel generators, have several drawbacks such as unreliable start of a diesel generator at low temperatures, maintenance of the generator due to rotary parts, and the pollution of the environment which is caused by exhaustive fumes from a diesel engine. This paper proposes the implementation of backup power supply based on proton exchange membrane (PEM) fuel cell and solar panel. In addition, it is also depicted the implementation of high-efficiency boost converter which provides adequate supply voltage for telecommunication devices. The benefits of the proposed solution are improved energy utilization, decreased need for maintenance and zero emission.

Application of QFD for enabling environmentally conscious design in an Indian rotary switch manufacturing organisation

Many businesses are recognising that environmental consciousness is an important concept for survival in today's highly competitive market. This paper presents a project in which quality function deployment (QFD) for environment (QFDE) has been applied to an Indian rotary switch manufacturing organisation to enable environmentally conscious design at the early stage of product development. QFDE consists of four phases. QFDE phases I and II are concerned with the identification of the rotary switch parts that are important in enhancing environmental consciousness. QFDE phases III and IV are concerned with the evaluation of the effect of design improvement on environmental quality requirements. The results obtained from the case study revealed that QFDE could be applied in the early stage of rotary switch product development as it identified the vital components from an environmental perspective and enabled the options for design improvement to be effectively evaluated. The managerial implications of the case study have also been presented.

Numerical Simulation Research on a New Spinning Process: Double-Roller Clamping Spinning Process

Thin-wall rotary parts with complex flange geometry have been widely used in many equipments, especially industrial fans and blowers. Conventional stamping and welding methods for those parts have some limitations such as low manufacturability, poor quality and low utilization ratio of material. Thus in this paper, a new spinning process, double-roller clamping spinning process (DCSP), is introduced to form the complex flange shape. During the process, the cylindrical workpiece made from sheet metal is held by the internal expanding clamp device and rotates together with the device, while two spinning rollers deforms and shapes the material of flange region according to the rollers moving paths. In order to deeply investigate deformation mechanisms of DCSP, both 2D and 3D FE simulation models are built and the spinning process for rectangular cross-section shape of flange is simulated by using explicit FE code ABAQUS/explicit. Simulation results show large flange length can induce wrinkles on the inner region of flange. After spinning process simulation, the springback of workpiece is calculated by implicit FE code ABAQUS/standard. The effect of flange length on the thickness reduction of workpiece is obtained by theoretical analysis.

Numerical Simulation of Double Rollers Clamping Spinning Process for Flanging

Double rollers clamping spinning (DRCS) is a new process to form thin-walled rotary shell parts with complex flange, which adopts two rollers to clamp the workpiece in the forming. Using FE simulation code ABAQUS/Explicit, the 3D simulation model of DRCS process for flanging is established, and the whole DRCS process and material deformation have been simulated. Distribution of equivalent stress, equivalent strain and wall thickness of flange in the DRCS process are obtained. And then, the effects of roller feed rate and flange length on the formed flange part are studied. Results show that equivalent stress, equivalent strain and reduction in wall thickness increase with the decrease of roller feed rate, while increase with the increase of flange length. The results obtained in this paper can provide the references to determine and optimize the new spinning process parameters.

An efficient method for solution of inverse dynamics of Stewart platform

PurposeThe purpose of this paper is to present an algorithm for inverse dynamics problem of a generally configured Stewart platform which is both fast and accurate.Design/methodology/approachA Newton‐Euler approach is presented, using the advantage of body coordinate frames, instead of inertial ones in order to omit redundant matrix transformations.FindingsThe method is found to lead to an efficient algorithm for inverse dynamics of a generally configured Stewart platform, which is at least three times faster than the available algorithms. This algorithm is at the same time more accurate, due to considering the gyroscopic effects of rotary parts within the legs.Originality/valueUtilizing body coordinate frames for both platform and legs (instead of inertial ones) and taking into account the gyroscopic effects of the rotary parts within the leg, are the innovative aspects of this paper. The more significant achievement of the presented method is the remarkably faster rate of convergence, which is very important in feedback linearization control.

Calculation and Analysis of Stator End-Winding Leakage Inductance of an Induction Machine

This paper proposes an improved method for calculating the value of and for analyzing the frequency-dependence of the stator end-winding leakage inductance of an induction machine. The method was based on the stored magnetic energy, which was calculated by a 3-D time-harmonic finite element analysis. In this method, there were no rotary parts in the model of the simulated machine. The results of the analysis show that the stator end-winding is capable of influencing the end of the active region of the machine whereas the influence on the central part of the active region is small. In addition, the phenomenon that the stator end-winding leakage inductance, as well as the magnetic energy in the machine, relates to the frequency of the stator current is explored.

An experimental study on the effect of air bubble injection on the flow induced rotational hub

Modification of shear stress due to air bubbles injection in a rotary device was investigated experimentally. Air bubbles inject to the water flow crosses the neighbor of the hub which can rotate just by water flow shear stresses, in this device. Increasing air void fraction leads to decrease of shear stresses exerted on the hub surface until in high void fractions, the hub motion stopped as observed. Amount of skin friction decrease has been estimated by counting central hub rotations. Wall shear stress was decreased by bubble injection in all range of tested Reynolds number, changing from 50,378 to 71,238, and also by increasing air void fraction from zero to 3.06%. Skin friction reduction more than 85% was achieved in this study as maximum measured volume of air fraction injected to fluid flow while bubbles are distinct and they do not make a gas layer. Significant skin friction reduction obtained in this special case indicate that using small amount of bubble injection causes large amount of skin friction reduction in some rotary parts in the liquid phases like as water.

An optoelectronic measurement system for measuring 6-degree-of-freedom motion error of rotary parts

This paper presents an optoelectronic measurement system for measuring 6 degree-of-freedom (DOF) motion error of rotary parts. It comprises a pyramid-polygon-mirror, three laser diodes and three 2-axis position sensing detectors (PSD). The laser/PSD pairs are arranged evenly around the pyramid-polygon-mirror, which is mounted rigidly on and aligned axially with the rotary part to be measured. Laser rays from the laser diodes are reflected off the respective mirrors to the respective PSDs. The incidence point of the laser ray on the PSD's surface varies with the pose of the pyramid-polygon-mirror, allowing the PSD to register variation in the mirror and, thereby, the rotary part. With appropriate orientation of the lasers and PSDs, this system can measure variation (error) during rotation of a rotary part. By use of skew-ray tracing and first order Taylor series expansion, the system achieves measurement of translational and rotational motion errors for each Cartesian axis. To validate the proposed methodology, a laboratory prototype system is built. System verification and stability tests are conducted to evaluate its performance. Stability test results show that measurement errors and maximum crosstalk are within +/-1 mum in translation and +/-1.5 arc sec in rotation.

An Accurate Digital Grinding Method on Inner Surface of Thin-Walled Rotary Part

The physics performance of thin-walled rotary parts made of hard brittle material on high-speed aerocraft cannot meet the technical requirements after semi-finished processing, in order to compensate the physics performance, the wall thickness should be properly grinded based on the inner surface reference in the finish machining. A processing method consisted of measuring, calculating and grinding functions is investigated. The data of complex surface is obtained with trigger measuring technology, and the reconstructed profile is calculated with cubic polynomial approaching algorithm, which has fast and stable merits in suit with efficient machining. The grinding G program is generated according to the concrete construction of machining tool. This method has been verified by experiments.

Modeling for Functional Expression of Rotary Apparatus. 1st Report. Clutch and Brake.

A new approach of modeling is put forward for expressing functions of clutch and brake directly, and their functional models are proposed in this report. Rotary motion is the most important type of motion for transmitting the kinetic energy, so many rotary parts and apparatus, for example crutch and brake, are used in most of machines. It is difficult to model function of the rotary element directly without relying on its structure by the conventional modeling approaches, for example the finite element method. The basic concept of the proposed approach is introduced, and the functional models of the hydraulic clutch with multiple plates, the clutch with vibration absorbing mechanism, the disc brake and the band brake are presented. Simulation results verify validity and usefulness of the proposed approach.

Flexible Manufacturing Systems: New Developments of Two Different Systems for Rotary Parts and Profile Milling Pieces

The development and application of modern production methods in the manufacturing field is characterized by an automation of the machining process, the production control as well as preparation of organizational tasks. As opposed to the situation during the past years, where mechanization played a dominant role in mass production, the present and future emphasis lies in adhering to the demands made on application-specific products. In this connection, it is essential to pay special attention to the requirements associated with small-scale and medium batch production by designing the manufacture in both a rational and economic manner. With the development of flexible manufacturing systems a start towards solving some of these problems was made.This contribution deals with the development and set-up of two flexible manufacturing systems that differ from each other in the machining tasks and application ranges. The paper describes modern demands on the information processing system meant for controlling complicated manufacturing set-ups and demonstrates possible solutions on two systems already commissioned.

A Study on the Stability of Fluid Machinery System with some References to the Characteristics of Prime Mover

In hitherto published works on surging phenomena or another unstable behaviours of fluid machinery system, they used to assume that the speed of revolution of the machine is constant throughout the behaviour. This assumption is removed in this study, and equations of revolving motion of rotary parts of machinery including prime mover, are taken into consideration as well as that of fluid motion in the pipe line. Outline of phenomena and criterion of stability were clarified by numerical solutions for several examples of two degrees of freedom.