Experiment Study on the Dynamic Characteristics of the Abrasive Flow in Centrifugal Grinding

2006 ◽  
Vol 304-305 ◽  
pp. 369-373 ◽  
Author(s):  
Hao Cheng Wang ◽  
H.T. Zhang ◽  
Q. Wang ◽  
T.W. Chen
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Planetary Gear ◽  
Scientific Basis ◽  
Gear Ratio ◽  
Design And Technology ◽  
Time Curve ◽  
Perceptual Knowledge ◽  
Profound Impact ◽  
High Efficient

Being a high efficient technique for metal surface treatment , centrifugal grinding is widely applied in the field of polishing and burring for small-sized asymmetric parts. During the process of centrifugal grinding, the dynamic characteristics of the abrasive flow, which is determined by the planetary driver ratio of the instrument, has a profound impact on the quality and producing efficiency of the workpiece. Targeting on the massive abrasive, this paper investigates experimentally theinfluence of the planetary driver ratio of the instrument to the producing quality and efficiency. On one hand, a high-speed photograph is employed to record the movement of the abrasive flow in the processing of centrifugal grinding. The dynamic characteristics of the abrasive flow have been investigated for different planetary driver ratios. By qualitative analyzing the high-speed photographing results, the perceptual knowledge of the characteristics and the kinematic rules of the abrasive flow have been obtained. On the other hand, the surface roughness data at different planetary gear ratio and polishing time have been measured. The influence of planetary gear ratio on producing process have been illustrated by plotting the roughness-time curve combined with the high-speed photograph so as to provide a scientific basis for optimizing the parameters of design and technology.

scholarly journals RESEARCH OPPORTUNITIES OF ROTREX SUPERCHARGER FOR APPLICATION IN EXHAUST SYSTEMS

2020 ◽  
Vol 1 (46) ◽  
pp. 183-189
Author(s):  
Lisoval A ◽  
Keyword(s):  
High Speed ◽  
Cooling System ◽  
Combustion Engine ◽  
Design Feature ◽  
Planetary Gear ◽  
Gear Ratio ◽  
Boost Pressure ◽  
Original Design ◽  
Compressor Wheel ◽  
Current Frequency

The purpose of the article is to describe the design and research of the new Rotrex superchargers of C15 series. In superchargers to ensure high boost pressure and efficiency centrifugal compressor wheel, shockless planetary gear of the original design, a special lubrication-cooling system were used. The article describes the design features of Rotrex centrifugal superchargers and the results of experimental researches of the C15 series supercharger on a motor less stand. The design feature of the C15 series superchargers is compactness and high speed - the compressor wheel speed reaches 200 000 rpm. In a planetary gear, cylindrical rollers on ball bearings are used instead of gear satellites. The gear ratio from the shaft of the stand motor to the shaft of the compressor wheel was 43. Tests of the C15-20 supercharger are performed in static modes. Characteristics of the consumer of boost air were modeled with special washers with minimum diameters of 10,1 ... 14,0 mm. The maximum overpressure of 1.1 ... 1.3 MPa was achieved at a flow rate of 460 ... 250 kg/h, respectively. The tests confirmed the efficiency of the stand for gas-dynamic research of centrifugal compressors, the electronic control system of the electric motor current frequency reliably worked. Characteristics of the C15-20 supercharger, test results confirmed its purpose for spark-ignition car engines. They can be used in combined boost systems of both gasoline engines and diesel engines. KEY WORDS: INTERNAL COMBUSTION ENGINE, BOOST, CENTRIFUGAL SUPERCHARGER, BOOST TESTS

Ball bearing turbocharger vibration management: application on high speed balancer

2020 ◽  
Vol 21 (6) ◽  
pp. 619
Author(s):  
Kostandin Gjika ◽  
Antoine Costeux ◽  
Gerry LaRue ◽  
John Wilson
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Ball Bearing ◽  
Squeeze Film ◽  
Design And Technology ◽  
Squeeze Film Damper ◽  
Damping Coefficients ◽  
Bearing Loads ◽  
Stiffness And Damping

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.

A modified damping model of vector form intrinsic finite element method for high-speed spiral bevel gear dynamic characteristics analysis

2021 ◽  
pp. 030932472110188
Author(s):  
Xiangying Hou ◽  
Yuzhe Zhang ◽  
Hong Zhang ◽  
Jian Zhang ◽  
Zhengminqing Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Numerical Solutions ◽  
Bevel Gear ◽  
Spiral Bevel Gear ◽  
Vector Form ◽  
Good Efficiency ◽  
Spiral Bevel ◽  
Damping Model

The vector form intrinsic finite element (VFIFE) method is springing up as a new numerical method in strong non-linear structural analysis for its good convergence, but has been constricted in static or transient analysis. To overwhelm its disadvantages, a new damping model was proposed: the value of damping force is proportional to relative velocity instead of absolute velocity, which could avoid inaccuracy in high-speed dynamic analysis. The accuracy and efficiency of the proposed method proved under low speed; dynamic characteristics and vibration rules have been verified under high speed. Simulation results showed that the modified VFIFE method could obtain numerical solutions with good efficiency and accuracy. Based on this modified method, high-speed vibration rules of spiral bevel gear pair under different loads have been concluded. The proposed method also provides a new way to solve high-speed rotor system dynamic problems.

scholarly journals Automatic Dissolution Testing with High-Temporal Resolution for Both Immediate-Release and Fixed-Combination Drug Tablets

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zhongmei Chi ◽  
Irfan Azhar ◽  
Habib Khan ◽  
Li Yang ◽  
Yunxiang Feng
Keyword(s):  
High Speed ◽  
Sequential Analysis ◽  
Immediate Release ◽  
Drug Dissolution ◽  
High Temporal Resolution ◽  
Dissolution Profile ◽  
Dissolution Testing ◽  
Combination Drug ◽  
Efficient Separation ◽  
High Efficient

AbstractDissolution testing plays many important roles throughout the pharmaceutical industry, from the research and development of drug products to the control and evaluation of drug quality. However, it is a challenging task to perform both high-efficient separation and high-temporal detection to achieve accurate dissolution profile of each active ingredient dissolved from a drug tablet. In our study, we report a novel non-manual-operation method for performing the automatic dissolution testing of drug tablets, by combining a program-controlled sequential analysis and high-speed capillary electrophoresis for efficient separation of active ingredients. The feasibility of the method for dissolution testing of real drug tablets as well as the performance of the proposed system has been demonstrated. The accuracy of drug dissolution testing is ensured by the excellent repeatability of the sequential analysis, as well as the similarity of the evaluation of dissolution testing. Our study show that the proposed method is capable to achieve simultaneous dissolution testing of multiple ingredients, and the matrix interferences can be avoided. Therefore it is of potential valuable applications in various fields of pharmaceutical research and drug regulation.

Dynamic characteristics of a drill in the drilling process

2003 ◽  
Vol 217 (2) ◽  
pp. 161-167 ◽  
Author(s):  
B W Huang
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Thrust Force ◽  
Time Dependent ◽  
Drilling Process ◽  
Improve Quality ◽  
Vibration Model ◽  
High Speed Drilling ◽  
Spinning Speed ◽  
Twisted Beam

The dynamic characteristics of high-speed drilling were investigated in this study. To improve quality and produce a higher production rate, the dynamic characteristics of the drilling process need to be studied. A pre-twisted beam is used to simulate the drill. The moving Winkler-type elastic foundation is used to approximate the drilling process. A time-dependent vibration model for drilling is presented. The spinning speed, pre-twisted angle and thrust force effects of the drill are considered. The numerical analysis indicates that the natural frequency is suddenly reduced as the drill moves into a workpiece.

scholarly journals Analysis of the dynamic characteristics of downsized aerostatic thrust bearings with different pressure equalizing grooves at high or ultra-high speed

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110180
Author(s):  
Ruzhong Yan ◽  
Haojie Zhang
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Rotation Speed ◽  
Dynamic Stiffness ◽  
Simulation Method ◽  
Perturbation Amplitude ◽  
Thrust Bearings ◽  
Supply Pressure ◽  
Ultra High Speed ◽  
Air Film

This study adopts the DMT(dynamic mesh technology) and UDF(user defined functions) co-simulation method to study the dynamic characteristics of aerostatic thrust bearings with equalizing grooves and compare with the bearing without equalizing groove under high speed or ultra high speed for the first time. The effects of air film thicness, supply pressure, rotation speed, perturbation amplitude, perturbation frequency, and cross section of the groove on performance characteristics of aerostatic thrust bearing are thoroughly investigated. The results show that the dynamic stiffiness and damping coefficient of the bearing with triangular or trapezoidal groove have obvious advantages by comparing with that of the bearing without groove or with rectangular groove for the most range of air film thickness, supply pressure, rotation speed, perturbation amplitude, especially in the case of high frequency, which may be due to the superposition of secondary throttling effect and air compressible effect. While the growth range of dynamic stiffness decreases in the case of high or ultra-high rotation speed, which may be because the Bernoulli effect started to appear. The perturbation amplitude only has little influence on the dynamic characteristic when it is small, but with the increase of perturbation amplitude, the influence becomes more obvious and complex, especially for downsized aerostatic bearing.

Development of High-Speed Response Electromagnetic Linear Actuator Using for Pneumatic Control Valve

2014 ◽  
Vol 532 ◽  
pp. 41-45 ◽  
Author(s):  
Myung Jin Chung
Keyword(s):  
Optimal Design ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Design Method ◽  
Control Valve ◽  
Design Parameters ◽  
Linear Actuator ◽  
Analytic Model ◽  
Electromagnetic Linear Actuator ◽  
Quadratic Programming Method

Analytic model of electromagnetic linear actuator in the function of electric and geometric parameters is proposed and the effects of the design parameters on the dynamic characteristics are analyzed. To improve the dynamic characteristics, optimal design is conducted by applying sequential quadratic programming method to the analytic model. This optimal design method aims to minimize the response time and maximize force efficiency. By this procedure, electromagnetic linear actuator having high-speed characteristics is developed.

Sign in / Sign up

Export Citation Format

Share Document