Four Pad Tilting Pad Bearing Design and Application for Multistage Axial Compressors

1982 ◽  
Vol 104 (4) ◽  
pp. 523-529 ◽  
Author(s):  
J. C. Nicholas ◽  
R. G. Kirk
Keyword(s):  
Test Stand ◽  
Operating Speed ◽  
Design Studies ◽  
Peak Response ◽  
Analytical Design ◽  
Rotor Systems ◽  
Axial Compressors ◽  
Tilting Pad ◽  
Speed Range ◽  
Bearing Design

The advantages of operating multistage axial compressors on 4 pad tilting pad bearings are discussed and compared to other fixed bore and tilting pad bearing designs. These advantages include operation free of subsynchronous vibration and, with between pivot loading, placement of peak response speeds well outside of the operating speed range. Examples of analytical design studies of 3 actual rotor systems are presented and discussed to illustrate the design recommendations. Test stand results are also included for 3 axial compressors to help substantiate the analytical results.

Nonlinear Transient Response of Tilting 4 Pad Bearings: Turbocharger Systems

2013 ◽  
Author(s):  
Jiayang Ying ◽  
Yinghou Jiao ◽  
Zhaobo Chen ◽  
R. Gordon Kirk ◽  
Yongxin Feng
Keyword(s):  
High Speed ◽  
High Performance ◽  
Dynamical Behavior ◽  
Transient Vibration ◽  
Nonlinear Dynamical ◽  
Rotor Systems ◽  
Tilting Pad ◽  
Speed Range ◽  
Nonlinear Transient ◽  
Tilting Pad Bearings

High speed and high performance engines are often equipped with turbochargers to increase power density over the operating speed range. Tilting pad bearings are now much more applied in many types of rotor systems. This paper presents nonlinear dynamical behavior of a typical turbocharger supported by two tilting 4 pad bearings. The bearing oil-film force was calculated by a database method and the influence of both pad offset and preload were studied. The nonlinear transient vibration is represented by bifurcation diagrams. The results directly show that pad offset and preload greatly influence the nonlinear vibrations of the turbocharger-tilting pad bearings system. In some certain speed range, the motions of the bearing pads are different from that of the bearing journal centerline.

Hybrid Active Vibration Control of Rotorbearing Systems Using Piezoelectric Actuators

1993 ◽  
Vol 115 (1) ◽  
pp. 111-119 ◽  
Author(s):  
A. B. Palazzolo ◽  
S. Jagannathan ◽  
A. F. Kascak ◽  
G. T. Montague ◽  
L. J. Kiraly
Keyword(s):  
Vibration Control ◽  
Search Algorithm ◽  
Active Vibration Control ◽  
Piezoelectric Actuators ◽  
Operating Speed ◽  
Speed Range ◽  
Active Vibration ◽  
Linear Fit ◽  
Hybrid Interface ◽  
Grid Search Algorithm

The vibrations of a flexible rotor are controlled using piezoelectric actuators. The controller includes active analog components and a hybrid interface with a digital computer. The computer utilizes a grid search algorithm to select feedback gains that minimize a vibration norm at a specific operating speed. These gains are then downloaded as active stiffnesses and dampings with a linear fit throughout the operating speed range to obtain a very effective vibration control.

Optimization of Bearing Locations for Rotor Systems With Magnetic Bearings

1995 ◽  
Author(s):  
Sriram Srinivasan ◽  
Eric H. Maslen ◽  
Lloyd E. Barrett
Keyword(s):  
Design Process ◽  
Magnetic Bearing ◽  
Rotating Machinery ◽  
Rotor Systems ◽  
Infinity Norm ◽  
Multi Stage ◽  
Scalar Measure ◽  
Bearing Design ◽  
The Stability ◽  
Practical Measure

This paper presents a method for quickly evaluating the effect of changes in bearing location on bearing design for stability of rotating machinery. This method is intended for use by rotating machinery designers to select the “best” bearing locations prior to the bearing design process. The purpose of the method is to improve the design process by separating the problem of determining the “best” bearing locations from that of determining the actual bearing design. The method is independent of the type of bearing employed. For each candidate bearing configuration, the method provides a scalar measure of the relative ability of bearings to meet stability specifications. Within certain limits, the stability specifications are defined by the designer. The scalar measure is used to rank the candidate bearing locations and thereby select the best one. The scalar measure is compared to a practical measure of magnetic bearing design such as the infinity norm of the controller for an example design of a multi-stage centrifugal compressor.

Using Dynamic Analysis for Compact Gear Design

1998 ◽  
Author(s):  
Ping-Hsun Lin ◽  
Hsiang Hsi Lin ◽  
Fred B. Oswald ◽  
Dennis P. Townsend
Keyword(s):  
Dynamic Response ◽  
Bending Strength ◽  
Three Dimensional ◽  
Spur Gear ◽  
Dynamic Factor ◽  
Operating Speed ◽  
Gear Design ◽  
Dynamic Factors ◽  
Speed Range ◽  
Response Change

Abstract This paper presents procedures for designing compact spur gear sets with the objective of minimizing the gear size. The allowable tooth stress and dynamic response are incorporated in the process to obtain a feasible design region. Various dynamic rating factors were investigated and evaluated. The constraints of contact stress limits and involute interference combined with the tooth bending strength provide the main criteria for this investigation. A three-dimensional design space involving the gear size, diametral pitch, and operating speed was developed to illustrate the optimal design of spur gear pairs. The study performed here indicates that as gears operate over a range of speeds, variations in the dynamic response change the required gear size in a trend that parallels the dynamic factor. The dynamic factors are strongly affected by the system natural frequencies. The peak values of the dynamic factor within the operating speed range significantly influence the optimal gear designs. The refined dynamic factor introduced in this study yields more compact designs than AGMA dynamic factors.

Thermally Induced Synchronous Instability of a Radial Inflow Overhung Turbine: Part I

1997 ◽  
Author(s):  
H. B. Faulkner ◽  
W. F. Strong ◽  
R. G. Kirk
Keyword(s):  
Thermal Expansion ◽  
Operating Speed ◽  
Lateral Motion ◽  
Turbine Wheel ◽  
Thermally Induced ◽  
Lateral Dynamics ◽  
Morton Effect ◽  
Speed Range ◽  
Differential Thermal Expansion ◽  
Rotor Dynamic

Abstract This paper is in two parts, and concerns the lateral dynamics of a large turbocharger rotor with overhung wheels. Initial rotor dynamic analysis indicated no excessive motion in the operating speed range. However, testing showed excessive motion, which was initially traced to the radial-inflow turbine wheel becoming loose on the shaft, due to transient differential thermal expansion in the wheel on startup. The attachment of the wheel was modified to eliminate this problem. The discussion up to this point is in Part I of the paper, and the remainder is in Part II. The wheel attachment modification extended the range of satisfactory operation upward considerably, but excessive lateral motion was again encountered near the upper end of the operating speed range. This behavior was traced to thermal bowing of the shaft at the turbine end, known as the Morton Effect. The turbine end bearing was modified to eliminate this problem, and satisfactory operation was then achieved throughout the operating speed range.

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