High Stiffness Bearing

1979 ◽  
Vol 101 (4) ◽  
pp. 520-525 ◽  
Author(s):  
Lech Brzeski ◽  
Zbyszko Kazimierski
Keyword(s):  
Experimental Investigation ◽  
Theoretical Model ◽  
General Principle ◽  
Journal Bearing ◽  
Stable Operation ◽  
High Stiffness ◽  
Bearing Load ◽  
New Type ◽  
Gas Journal Bearing ◽  
Very High

A new type of high stiffness gas or liquid lubricated bearing is presented. The general principle and bearing configuration are explained. The theoretical model of the bearing is given for a case of gas journal bearing. Load versus displacement data were determined both theoretically and experimentally. The results obtained confirmed the very high stiffness of the bearing. The experimental investigation of the bearing demonstrated its stable operation.

High Stiffness Gas Journal Bearing Under Harmonic Excitation

1994 ◽  
Author(s):  
Krzysztof Czolczynskl
Keyword(s):  
Degrees Of Freedom ◽  
Dynamic Models ◽  
Journal Bearing ◽  
Harmonic Excitation ◽  
Harmonic Load ◽  
High Stiffness ◽  
Bearing Stiffness ◽  
Stiffness And Damping ◽  
Gas Bearing ◽  
Gas Journal Bearing

This paper presents an analysis of the dynamic response of the high stiffness gas journal bearing to a harmonic load. The dependence between the frequency of the load, and the amplitude and phase angle of the shaft vibration are estimated from numerical simulation. Results of this simulation enable an attempt of identification of the high stiffness bearing as a linear system with two (or in simplification - one) degrees of freedom, to formulate simple dynamic models of the bearing. Stiffness and damping coefficients are calculated and compared with the simple gas journal bearing. The comparison suggests, that the investigated gas bearing retains high stiffness not only for slow changes of the load which appear in its application to grinding machines, but even when the frequency of the load is equal to several rad/s.

High stiffness gas journal bearing under the step force

Wear ◽  
1993 ◽  
Vol 167 (1) ◽  
pp. 49-58 ◽  
Author(s):  
K. Czołczyński ◽  
L. Brzeski ◽  
Z. Kazimierski
Keyword(s):  
Journal Bearing ◽  
High Stiffness ◽  
Gas Journal Bearing

An Experimental Investigation of the Effect of Inter-Orifice Variations on the Performance of an Externally-Pressurized, Orifice-Compensated Air Journal Bearing

1980 ◽  
Vol 102 (4) ◽  
pp. 505-510
Author(s):  
T. B. Stowell ◽  
P. H. Markho ◽  
S. S. Grewal
Keyword(s):  
Experimental Investigation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Radial Stiffness ◽  
Bearing Load ◽  
Design Value ◽  
Orifice Size

The performance of an externally-pressurized, orifice-compensated air journal bearing fitted with various combinations of nonuniform supply orifices of known size is compared with the performance of the same bearing fitted with uniform orifices. In general, it is found that even a substantial amount of scatter in orifice size about a mean, design value does not result in a marked deterioration in bearing performance. Furthermore, the bearing load capacity at a given eccentricity may actually be enhanced (at the expense of a relatively smaller reduction in radial stiffness) by using nonuniform orifices, the best arrangement being one where there is a progressive, circumferential variation of orifice size.

NUMERICAL AND EXPERIMENTAL INVESTIGATION ON A NEW TYPE ELECTRICAL HEAT STORAGE BASED ON FLAT MICRO HEAT PIPE

2018 ◽  
Author(s):  
Zeyu Wang ◽  
Yanhua Diao ◽  
Yaohua Zhao ◽  
Chuanqi Chen ◽  
Lin Liang ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Heat Pipe ◽  
Heat Storage ◽  
Micro Heat Pipe ◽  
New Type

Experimental Investigation of very High Frequency Slot Antenna on M-60A-1 Tank

1977 ◽  
Author(s):  
D. V. Campbell ◽  
William Kennebeck ◽  
A. Zanella ◽  
Paul Sexton
Keyword(s):  
Experimental Investigation ◽  
High Frequency ◽  
Slot Antenna ◽  
Very High Frequency ◽  
Very High

scholarly journals Improvement of Tilting-Pad Journal Bearing Operating Characteristics by Application of Eddy Grooves

Lubricants ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 18
Author(s):  
Eckhard Schüler ◽  
Olaf Berner
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Load Capacity ◽  
Fluid Film ◽  
Operating Characteristics ◽  
Fluid Film Bearings ◽  
Tilting Pad ◽  
Bearing Load ◽  
Bearing Loads ◽  
Tilting Pad Journal Bearing

In high speed, high load fluid-film bearings, the laminar-turbulent flow transition can lead to a considerable reduction of the maximum bearing temperatures, due to a homogenization of the fluid-film temperature in radial direction. Since this phenomenon only occurs significantly in large bearings or at very high sliding speeds, means to achieve the effect at lower speeds have been investigated in the past. This paper shows an experimental investigation of this effect and how it can be used for smaller bearings by optimized eddy grooves, machined into the bearing surface. The investigations were carried out on a Miba journal bearing test rig with Ø120 mm shaft diameter at speeds between 50 m/s–110 m/s and at specific bearing loads up to 4.0 MPa. To investigate the potential of this technology, additional temperature probes were installed at the crucial position directly in the sliding surface of an up-to-date tilting pad journal bearing. The results show that the achieved surface temperature reduction with the optimized eddy grooves is significant and represents a considerable enhancement of bearing load capacity. This increase in performance opens new options for the design of bearings and related turbomachinery applications.

scholarly journals Measurement of Electrical Properties of Superconducting YBCO Thin Films in the VHF Range

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3360
Author(s):  
Yakir Dahan ◽  
Eldad Holdengreber ◽  
Elichai Glassner ◽  
Oz Sorkin ◽  
Shmuel E. Schacham ◽  
...  
Keyword(s):  
Thin Films ◽  
Theoretical Model ◽  
Quality Factor ◽  
High Frequency ◽  
Unit Length ◽  
Superconducting Thin Films ◽  
Electrical Parameters ◽  
Very High Frequency ◽  
Production Constraints ◽  
Very High

A new measurement technique of electrical parameters of superconducting thin films at the Very High Frequency (VHF) range is described, based on resonators with microstrip (MS) structures. The design of an optimal resonator was achieved, based on a thorough theoretical analysis, which is required for derivation of the exact configuration of the MS. A theoretical model is presented, from which an expression for the attenuation of a MS line can be derived. Accordingly, simulations were performed, and an optimal resonator for the VHF range was designed and implemented. Production constraints of YBa2Cu3O7 (YBCO) limited the diameter of the sapphire substrate to 3″. Therefore, a meander configuration was formed to fit the long λ/4 MS line on the wafer. By measuring the complex input reflection coefficients of a λ/4 resonator, we extracted the quality factor, which is mainly affected by the dielectric and conductor attenuations. The experimental results are well fitted by the theoretical model. The dielectric attenuation was calculated using the quasi-static analysis of the MS line. An identical copper resonator was produced and measured to compare the properties of the YBCO resonator in reference to the copper one. A quality factor of ~6·105 was calculated for the YBCO resonator, three orders of magnitude larger than that of the copper resonator. The attenuation per unit length of the YBCO layer was smaller by more than five orders of magnitude than that of the copper.

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