Auxiliary Bearing System Optimization for AMB Supported Rotors Based on Rotor Drop Analysis: Part II — Optimization for Example Vertical and Horizontal Machines

2016 ◽  
Author(s):  
Jianming Cao ◽  
Paul Allaire ◽  
Timothy Dimond ◽  
Saeid Dousti
Keyword(s):  
Ball Bearing ◽  
System Optimization ◽  
Analysis Method ◽  
Design And Optimization ◽  
Size Number ◽  
Auxiliary Bearing ◽  
Bearing Design ◽  
Bearing Stress ◽  
Bearing Damage ◽  
Bearing System

This paper forms Part II of the rotor drop analysis, focusing on the auxiliary bearing system design and optimization based on the rotor drop analysis methods, as introduced in Part I. Optimization focuses on shaft orbit, maximum ball bearing stress, and how to avoid possible ball bearing damage due to impact loading during rotor drop by optimizing auxiliary design including bearing selection, preload method, radial and axial damping element, and flexible bearing support. Using the detailed rotor drop model and time transient method, a variety of simulations are presented for 1) an energy storage vertical flywheel system, and 2) an 8-stage horizontal centrifugal compressor, are conducted to investigate the effects of auxiliary bearing design and to optimize the auxiliary system. Axial drops, radial drops and combination of radial/axial drops are all evaluated considering angular contact auxiliary bearing size, number of rows, preload, and flexible damped bearing supports in the axial and radial directions. The rotor drop analysis method introduced in this paper may be used as a design toolbox for the auxiliary bearing system.

Auxiliary Bearing System Optimization for AMB Supported Rotors Based on Rotor Drop Analysis: Part I — Rotor Drop Analysis Method

2016 ◽  
Author(s):  
Jianming Cao ◽  
Paul Allaire ◽  
Timothy Dimond ◽  
Saeid Dousti
Keyword(s):  
Ball Bearing ◽  
System Optimization ◽  
American Petroleum Institute ◽  
Operating Conditions ◽  
Rolling Element Bearing ◽  
Hertzian Contact ◽  
Analysis Method ◽  
Contact Loads ◽  
Auxiliary Bearing ◽  
Bearing System

For rotors supported with active magnetic bearings (AMBs), the auxiliary bearing system or backup bearing system is needed to avoid serious potential internal damaging in the event of AMB loss of power or overload. The evolution of auxiliary systems has been made a priority by the American Petroleum Institute using analytical or experimental methods. In part I of this paper, a detailed rotor drop nonlinear transient analysis method including flexible shaft, rolling element bearing components including inner/outer races and balls, as well as flexible/damped supporting structures is given. A finite element based 6-DOF flexible rotor model is used to indicate shaft motion before the drop (operating conditions) and during the rotor drop event. Un-lubricated Hertzian contact models are used between the shaft and inner/outer races, between balls and races. To avoid heavy calculating time, two different methods to calculate ball bearing contact loads are discussed and the simulation results are compared. These models are applied to predict shaft-race-ball displacements and angular speeds, contact loads and ball bearing stresses during the drop for angular contact auxiliary bearings. This method also can be used to design and optimize the auxiliary bearing system as presented in the 2nd part of this paper.

A fuzzy logic neural network algorithm for compressor crankshaft-rolling bearing system optimization

2021 ◽  
pp. 1-7
Author(s):  
Zheng Zhang ◽  
Jianrong Zheng
Keyword(s):  
Neural Network ◽  
Fuzzy Logic ◽  
Dynamic Analysis ◽  
Weighted Average ◽  
Rolling Bearing ◽  
System Optimization ◽  
Simulation Software ◽  
Network Algorithm ◽  
Neural Network Algorithm ◽  
Bearing System

Taking the crankshaft-rolling bearing system in a certain type of compressor as the research objective, dynamic analysis software is used to conduct detailed dynamic analysis and optimal design under the rated power of the compressor. Using Hertz mathematical formula and the analysis method of the superstatic orientation problem, the relationship expression between the bearing force and deformation of the rolling bearing is solved, and the dynamic analysis model of the elastic crankshaft-rolling bearing system is constructed in the simulation software ADAMS. The weighted average amplitude of the center of the neck between the main bearings is used as the target, and the center line of the compressor cylinder is selected as the design variable. Finally, an example analysis shows that by introducing the fuzzy logic neural network algorithm into the compressor crankshaft-rolling bearing system design, the optimal solution between the design variables and the objective function can be obtained, which is of great significance to the subsequent compressor dynamic design.

Parameters research on time-varying stiffness of the ball bearing system without race control hypothesis

2021 ◽  
pp. 095440622110179
Author(s):  
Yongzhen Liu ◽  
Yimin Zhang
Keyword(s):  
Ball Bearing ◽  
Combined Loading ◽  
Time Varying ◽  
Noticeable Effect ◽  
Rotating Speed ◽  
Bearing Stiffness ◽  
Vibration Mechanism ◽  
Control Hypothesis ◽  
Full Consideration ◽  
Bearing System

When the ball bearing serving under the combined loading conditions, the ball will roll in and out of the loaded zone periodically. Therefore the bearing stiffness will vary with the position of the ball, which will cause vibration. In order to reveal the vibration mechanism, the quasi static model without raceway control hypothesis is modeled. A two-layer nested iterative algorithm based on Newton–Raphson (N-R) method with dynamic declined factors is presented. The effect of the dispersion of bearing parameters and the installation errors on the time-varying carrying characteristics of the ball-raceway contact and the bearing stiffness are investigated. Numerical simulation illustrates that besides the load and the rotating speed, the dispersion of bearing parameters and the installation errors have noticeable effect on the ball-raceway contact load, ball-inner raceway contact state and bearing stiffness, which should be given full consideration during the process of design and fault diagnosis for the rotor-bearing system.

A Proof-of-Principle Study of the Design and Optimization of a Novel Fluid-Driven Automated Retracting Needle System

2021 ◽  
Vol 15 (3) ◽  
Author(s):  
W. J. Geelhoed ◽  
M. Boonekamp ◽  
H. van de Stadt ◽  
S. Badulescu ◽  
R. A. Lalai ◽  
...  
Keyword(s):  
Response Time ◽  
Ex Vivo ◽  
System Optimization ◽  
Common Adverse Event ◽  
Membrane Composition ◽  
Design And Optimization ◽  
Hematoma Formation ◽  
Essential Interventions ◽  
Prototype Design ◽  
Hemodialysis Machine

Abstract The cannulation of blood vessels is one of the most basic and essential interventions in medical practice. A common adverse event of this procedure is miscannulation with infiltration of the second part of the vessel wall, often resulting in a perivascular hematoma. In hemodialysis patients, surgically created arteriovenous conduits are cannulated 3–4 times per week to provide sufficient blood supply to the hemodialysis machine. However, the high blood flow and pressure in these vascular access sites increase the risk of complications upon miscannulation. A novel needle system that allows for rapid automatic retraction of the needle in response to contact with blood after positioning the cannula in the blood vessel was developed to reduce the risk of miscannulation. The device can easily be incorporated into existing needle designs. The mechanical functionality of the device was validated by testing prototypes in an ex vivo system. Optimization of the needle system was performed to enhance response time and piston shape. A final prototype design was manufactured and validated. The optimal membrane composition and piston shape were determined, which resulted in a needle response time of 40 ms upon contact with fluid at a pressure of 100 mmHg (arterial pressure). Here, we have successfully designed, mechanically validated, and tested a novel automated rapid needle retraction system that allows incorporation into existing needle systems. This device could notably decrease the difficulty of vessel cannulation and the prevalence of hematoma formation.

Systematical Analysis Method for the Mechanical Behaviors of Crankshaft-Bearing System

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Changlin Gui ◽  
Jun Sun ◽  
Zhixian He ◽  
Zhen Li
Keyword(s):  
Elastic Deformation ◽  
Dynamic Stress ◽  
Analysis Method ◽  
Mechanical Behaviors ◽  
Remarkable Effect ◽  
Journal Misalignment ◽  
Bearing System

Various mechanical behaviors will happen at the same time when an engine operates. Based on this concept, in this paper, a systematical analysis method is presented to analyze the multiple mechanical behaviors (tribology, dynamics, stiffness, and strength) of the crankshaft-bearing system in an engine. By this method, the analyses of the tribology of bearing, the dynamics of crankshaft-bearing system and the dynamic stress of crankshaft can be accomplished simultaneously. For example, the effect of the journal misalignment of crankshaft and the elastic deformation of bearing bush on the dynamics of crankshaft-bearing system, the tribological performances of main bearings and the dynamic stress of crankshaft are analyzed emphatically. The results show that the journal misalignment of crankshaft and the elastic deformation of bearing bush have remarkable effect on the tribological performances of main bearings and the dynamic stress of crankshaft, but have little effect on the dynamics of crankshaft-bearing system.

Optimization in a Design System for Complex Products

1992 ◽  
Author(s):  
Johan Malmqvist
Keyword(s):  
Parametric Design ◽  
System Optimization ◽  
Optimization Method ◽  
Design System ◽  
Design Problems ◽  
Design And Optimization ◽  
Complex Products ◽  
Knowledge Based ◽  
Product Models ◽  
Use Of Knowledge

Abstract This paper describes a system for parametric design and optimization of complex products. In the system, the use of knowledge-based and mathematical programming methods is combined. The motivation is that while knowledge-based methods are well suited for modeling products, they are insufficient when dealing with design problems that can be given an optimization formulation. This weakness was approached by including the information necessary for stating an optimization problem in the product models. A system optimization method can then be applied. The system also performs sensitivity analysis and has an interactive optimization module. The use of the system is illustrated by an example; the design and optimization of a two-speed gearbox.

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