Micro Turbocharger on a Single Silicon Rotor

2004 ◽  
Author(s):  
P. Kang ◽  
S. Tanaka ◽  
M. Esashi
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Rotation Speed ◽  
Bonding Temperature ◽  
Preliminary Test ◽  
Anodic Bonding ◽  
Thrust Bearings ◽  
High Speed Rotation ◽  
Speed Up ◽  
Speed Rotation

This paper describes the design, fabrication and preliminary test of a MEMS-based turbocharger. In this device, a compressor and a turbine are formed on the same side of the rotor to escape miss-alignment during bonding process. The rotor is supported by hydrostatic journal and thrust bearings. The device rotated only at low rotation speed up to 2500 rpm, and the rotation speed did not remarkably changed by adjusting air supplies to the hydrostatic bearings. From the test results, we found important issues to be solved for high speed rotation. Concerning to fabrication, flat and smooth bearing surfaces is difficult to fabricate, and bearing/tip clearances are difficult to precisely control due to spikes on etched surfaces and the warp of the devices induced by anodic bonding. We developed special deep RIE recipe to realize spike-free, uniform etching. And, we found that the wafer warp became negligible at a bonding temperature of 320 °C and an applied voltage of 400–600 V, when a 1 mm thick Pyrex glass substrate was used. Even after 5 times anodic bonding to stack 6 wafers, the warp was below 2 μm. The other concern is on bearing design. The journal bearing has a very low L/D number (length divided by diameter). As a result, the journal bearing has a small journal surface, and it is difficult to install orifices on the journal bearing. Additionally, there is interference between the journal and thrust bearing due to air leakage.

The Performance of the Hydraulic Expansion Toolholder in High-Speed Rotation

2011 ◽  
Vol 188 ◽  
pp. 457-462 ◽  
Author(s):  
Shu Lin Wang ◽  
Wei Zhan Zhang ◽  
Qin Zhang ◽  
G. Liu ◽  
Z.J. Yang
Keyword(s):  
Finite Element Analysis ◽  
High Speed ◽  
Rotation Speed ◽  
Analysis Software ◽  
Element Analysis ◽  
Fluid Analysis ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
High Rotation Speed ◽  
Pressure Changes

On the basis of finite element analysis, the static transmitted torque of Hydraulic Expansion Toolholder is validated. At the same time fluid analysis software is used to investigate the oil pressure changes in oil chamber wall because of different rotation speed. Then through the fluid-solid coupling, the article analyzes the chuck clamping performance on the factors of expansion chuck and tool clearance, rotation speed, and hydraulic oil pressure when toolholder on the state of high rotation speed.

scholarly journals Sound Noise Generated from Ball Bearing in High Speed Rotation

1978 ◽  
Vol 21 (158) ◽  
pp. 1306-1310 ◽  
Author(s):  
Akio NAGAMATSU ◽  
Masaho FUKUDA
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
High Speed Rotation ◽  
Speed Rotation

Analysis of the Lubrication Regimes at the Small End and Big End of a Connecting Rod of a High Performance Motorbike Engine

2012 ◽  
Author(s):  
Luca Bertocchi ◽  
Matteo Giacopini ◽  
Daniele Dini
Keyword(s):  
Rotational Speed ◽  
High Speed ◽  
High Performance ◽  
Hydrodynamic Lubrication ◽  
Vertical Axis ◽  
Connecting Rod ◽  
Lubrication Regimes ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Squeeze Effect

In the present paper, the algorithm proposed by Giacopini et. al. [1], based on a mass-conserving formulation of the Reynolds equation using the concept of complementarity is suitably extended to include the effects of compressibility, piezoviscosity and shear-thinning on the lubricant properties. This improved algorithm is employed to analyse the performance of the lubricated small end and big end bearings of a connecting rod of a high performance motorbike engine. The application of the algorithm proposed to both the small end and the big end of a con-rod is challenging because of the different causes that sustain the hydrodynamic lubrication in the two cases. In the con-rod big end, the fluid film is mainly generated by the relative high speed rotation between the rod and the crankshaft. The relative speed between the two races forms a wedge of fluid that assures appropriate lubrication and avoids undesired direct contacts. On the contrary, at the con-rod small end the relative rotational speed is low and a complete rotation between the mating surfaces does not occurs since the con-rod only oscillates around its vertical axis. Thus, at every revolution of the crankshaft, there are two different moments in which the relative rotational speed between the con-rod and the piston pin is null. Therefore, the dominant effect in the lubrication is the squeeze caused by the high loads transmitted through the piston pin. In particular both combustion forces and inertial forces contribute to the squeeze effect. This work shows how the formulation developed by the authors is capable of predicting the performance of journal bearings in the unsteady regime, where cavitation and reformation occur several times. Moreover, the effects of the pressure and the shear rate on the density and on the viscosity of the lubricant are taken into account.

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.

Research on Calibration Method of Tire Dynamic Balance Detection System

2012 ◽  
Vol 542-543 ◽  
pp. 828-832 ◽  
Author(s):  
Jing Fang Yang ◽  
Xian Ying Feng ◽  
Hong Jun Fu ◽  
Lian Fang Zhao
Keyword(s):  
High Speed ◽  
Detection System ◽  
Dynamic Balance ◽  
Calibration Method ◽  
Engineering Practice ◽  
Influence Coefficient ◽  
Quality Factors ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Upper Rim

Tire dynamic balance detection plays an important part in tire quality detection area. This paper uses the two-sided balance method to obtain the unbalance of the tire. According to the engineering practice, builds kinetic model and then introduces the calculating principle and operating procedures. In order to accurately determine the influence coefficient, a calibration method without tire is put forward. Further more, this new method is able to eliminate the unbalance caused by non-quality factors to some extent. But this method is presented based on the relative position invariance of the upper rim and lower rim, even both of them are under high-speed rotation situation. Finally, the experimental data acquired from both of the two methods are compared. The calibration method without tire is proved to be more feasible, efficient and accurate.

Improvement of Silver Recovery Efficiency by High-Speed Rotation

2003 ◽  
Vol 439 ◽  
pp. 156-162
Author(s):  
A. Da Camara ◽  
Joaquín Lira-Olivares ◽  
Soo Wohn Lee ◽  
H.D. Park ◽  
Y.S. Park
Keyword(s):  
High Speed ◽  
Recovery Efficiency ◽  
Silver Recovery ◽  
High Speed Rotation ◽  
Speed Rotation

An experimental investigation of a microturbine simulated rotor supported on multileaf gas foil bearings with backing bump foils

2017 ◽  
Vol 232 (9) ◽  
pp. 1169-1180 ◽  
Author(s):  
Bo Zhang ◽  
Shemiao Qi ◽  
Sheng Feng ◽  
Haipeng Geng ◽  
Yanhua Sun ◽  
...  
Keyword(s):  
High Speed ◽  
Preliminary Test ◽  
Journal Bearings ◽  
Rotating Machinery ◽  
System Stability ◽  
Test Rig ◽  
Thrust Bearings ◽  
Foil Bearings ◽  
Simulated System ◽  
First Time

Two multileaf gas foil journal bearings with backing bump foils and one set of gas foil thrust bearings were designed, fabricated, and used in a 100 kW class microturbine simulated rotor system to ensure stability of the system. Meanwhile, a preliminary test rig had been built to verify the simulated system stability. The rotor synchronous and subsynchronous responses were well controlled by using of the gas foil bearings. It is on the multileaf gas foil bearings with backing bump foils that the test was conducted and verified for the first time in open literatures. The success in the experiments shows that the design and fabrication of the rotor and the gas foil bearings can provide a useful guide to the development of the advanced high speed rotating machinery.

High-speed Rotation and Speed Stability of the Sodium-driven Flagellar Motor inVibrio alginolyticus

1995 ◽  
Vol 251 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Kazumasa Muramoto ◽  
Ikuro Kawagishi ◽  
Seishi Kudo ◽  
Yukio Magariyama ◽  
Yasuo Imae ◽  
...  
Keyword(s):  
High Speed ◽  
Flagellar Motor ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Speed Stability
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