Seal Device Research Articles

Mechanical seal device

Mechanical seal device

Seal device with sensor and bearing device for wheel

Seal device with sensor and bearing device for wheel

Sensor-equipped seal device and wheel bearing

Sensor-equipped seal device and wheel bearing

Shaft seal device

Shaft seal device

Numerical and experimental analysis of the rotor—bearing—seal system

The rotor—bearing—seal system is simulated by a model consisting of the rotor, the bearing, the foundation, and the labyrinth seal. Governing equations are set up theoretically using the finite-element method. The equivalent model of the bearing—foundation support system is analysed. Forces from the bearing—foundation support and gas-excited forces in the labyrinth seal are imposed in the finite-element equations. Then an experimental rotor—bearing—seal device is designed and many tests are carried out. The Bode, orbit, and waterfall plots are all constructed from the experimental data. An experimental rotor system is studied using the developed equations. Theoretical results from the developed model are in agreement with the ones from the experiment. Analysis proves that although the gas-excited force in the labyrinth seal can improve the stable region of the rotor—bearing—seal system, it makes the rotor vibrate more violently and initiates destructive impacts within the rotor system when the rotor running speed reaches a certain level. Oil whirl and oil whip of journal bearings are found in both the theoretical calculation and the experiment.

Mechanical seal device

Mechanical seal device

A multifunctional seal device for a valve for a drinking receptacle

A multifunctional seal device for a valve for a drinking receptacle

Seal device

Seal device

Shaft seal device for fluid machine

Shaft seal device for fluid machine

Asset seal device and method

Asset seal device and method

Experimental and numerical analysis of nonlinear dynamics of rotor–bearing–seal system

Nonlinear dynamics and stability of the rotor–bearing–seal system are investigated both theoretically and experimentally. An experimental rotor–bearing–seal device is designed and corresponding tests are carried out. The experimental rotor system is simplified as the Jeffcott rotor. The nonlinear oil–film forces are obtained under the short bearing theory and Muszynska nonlinear seal force model is used. Numerical method is utilized to solve the nonlinear governing equations. Bifurcation diagrams, waterfall plots, Poincare maps, spectrum plots and rotor orbits are drawn to analyze various nonlinear phenomena and system unstable processes. Theoretical results from numerical analysis are in good agreement with results from experiments. Conclusions are drawn and prove that this study will contribute to the further understanding of nonlinear dynamics and stability of the rotor system with the fluid-induced forces from oil–film bearings and the seals.

Mechanical seal device

Mechanical seal device

Mechanical seal and mechanical seal device

Mechanical seal and mechanical seal device

Mechanical seal device

Mechanical seal device

Design and Stress Analysis of a New Quick-Opening Seal Device Connected by D-Shaped Shearing Bolts

Because of large scale and heavy weight, end closures of high pressure vessels are usually hard to assemble and disassemble. In this paper, a new quick-opening seal device connected by D-shaped shearing bolts is introduced. This device is compact in structure, reliable in sealing, easy in assembly and disassembly, and very appropriate for end closures of pressure vessels or for pipe joints. Strength calculation formulas for the major parts are proposed analytically, and stress analysis using the finite element method for a C-ring seal has been performed. An application of this device shows that its sealing and strength is reliable.

Development of a gel monolithic column polydimethylsiloxane microfluidic device for rapid electrophoresis separation

A β-cyclodextrin (β-CD)-bonded gel monolithic column polydimethylsiloxane (PDMS) microfluidic device was developed in a simple and feasible way. Before preparation of gel monolithic column in PDMS microchannel, PDMS surface was activated by UV light to create silanol groups, which is an active molecule to covalently bond 3-(trimethoxysilyl)-propyl methacrylate (Bind-Silane) and seal microfluidic device. By the way, Bind-Silane is a bifunctional molecule to link polyacrylamide (PAA) gel and inner wall of PDMS microchannel covalently. Allyl-β-CD was used not only as a multifunctional crosslinker in PAA gel to control the size of the pores, but also as a chiral selector for the enantioseparation. The stability, transferring heat and optical characteristic of the microfluidic device were examined. The separation capability of the gel monolithic column was confirmed by the successful separation of fluorescein isothiocyanate (FITC)-labeled arginine (Arg), glutamine acid (Glu), tryptophan (Try), cysteine (Cysteine) and phenylalanine (Phe) in the PDMS microfluidic device less than 100 s at 36 mm effective separation length. A maximum of 2.06 × 10 5 theoretical plates was obtained by the potential strength of 490 V/cm. A pair of FITC-labeled dansyl- d, l-threonine (Dns-Thr) was separated absolutely.

Comparison between Flutter Valve Drainage Bag and Underwater Seal Device for Pleural Drainage after Lung Surgery

The purpose of the present study was to compare the use of a conventional underwater seal device with suction and a flutter valve drainage bag for pleural drainage after lung surgery. Altogether 59 patients undergoing elective lung surgery except pneumonectomy between February 2001 and April 2002 were prospectively randomized to receive postoperative pleural drainage by 28F chest tube(s) attached to underwater seal device placed on negative pressure of 15 cm of water or flutter valve drainage bag. Following withdrawal of four patients from the study, 55 patients were evaluated (31 patients in the underwater seal device group and 24 patients in the flutter valve drainage bag group). In the conventional underwater seal device group the mean drainage time was 2.6 (SD +/- 2.0) days and in the flutter valve drainage bag group the mean drainage time was 3.3 days (SD +/- 4.0); difference -0.8, 95% confidence interval (CI) -2.4 to 0.9. The mean length of hospitalization in the surgical ward was 3.6 (SD +/- 2.7) and 4.1 (SD +/- 4.4) days respectively (difference -0.5, 95% CI -2.5 to 1.4). The results of this study suggest that flutter valve drainage system is a safe and feasible alternative in managing postoperative air leaks and haemorrhage after lung surgery other than pneumonectomy if air leaks are not extremely massive.

Design and pressure control of high-pressure differential magnetic fluid seals

Magnetic fluid seals have wide applications. The common two poles multistage seals cannot achieve a high seal capacity. Multipole and multistage magnetic fluid seals are an effective way to obtain a rather high seal capacity. In this paper, the design method for multipole and multistage magnetic fluid seals is presented. Methods to fill the magnetic fluid and to apply a pressure differential are investigated. Experimental results show that the designed seal device can bear a pressure differential of 2.7 MPa. By a pressure applying control method, the seal capacity can be further increased.

Numerical analysis on the action of centrifuge force in magnetic fluid rotating shaft seals

The magnetic fluid seal is suitable for high-speed rotating shaft seal applications. Centrifuge force will have evident influence on magnetic fluid rotating shaft seals. The seal capacity of the rotating shaft seal can be improved or increased by some measures. Through hydrodynamic analysis the moving status of the magnetic fluid is worked out. By numerical method, the magnetic field and the isobars in the magnetic fluid of a seal device are computed. Then the influence of the centrifuge force on the magnetic fluid seal is calculated quantitatively.

A07 ハーメティック形スターリングエンジンの性能特性

A hermetic Stirling engine, which has a generator in a pressurized crankcase, is suitable for an application of a generator set. Because the hermetic engine does not have an external seal device between the working space and the atmosphere, and it has small mechanical loss. In this paper, the author reorganizes a 100 W class Stirling engine named "Ecoboy-SCM81" to the hermetic type. The original engine was developed at a RC127 committee of JSME in 1995,and it had a mechanical seal as the external seal device. And, the performance of the hermetic engine is measured for a comparison with that of the original engine. As the result, it is confirmed that the hermetic engine has very smaller mechanical loss and higher generator power than that of the original engine.