Oil Seal Research Articles

Сальниковое уплотнение с применением материалов с эффектом памяти формы для насосов, используемых при перекачке сжиженного природного газа

Сальниковое уплотнение с применением материалов с эффектом памяти формы для насосов, используемых при перекачке сжиженного природного газа

Cross-Sectional Shape Optimization of Secondary Damper Oil Seal for Rolling Stock

Cross-Sectional Shape Optimization of Secondary Damper Oil Seal for Rolling Stock

Effect of roughness on sealing performance of oil seals with surface texture

PurposeThis paper aims to obtain the film thickness, friction torque and pumping rate and analyze the effects of roughness and surface micro-dimple texture (circular, square and equilateral triangle) on the performance of the oil seal.Design/methodology/approachOn the basis of elastohydrodynamic lubrication and the pumping mechanism of rotating shaft seal, this paper establishes a numerical model of hybrid lubrication of oil seal in sealing area. The model is coupled with fluid mechanics, rough peak contact mechanics and deformation analysis.FindingsThe results show that surface texture significantly improves the lubrication properties of the oil seal. The oil seal with the square texture has the largest oil film thickness, while the equilateral triangle texture has a better effect on the pumping rate.Originality/valueTo get closer to the real working environment of the oil seal, based on the surface roughness, this paper studies the effect of the texture shapes applied to the oil seal lip surface on the performance of the oil seal. The critical roughness and rotational speed values with zero pumping rate are obtained, which provides a theoretical basis for the correct selection of oil seals.

The dynamic simulation and experiment of bearing capacity of multi oil cushion static bearing with double rectangular cavities

PurposeThe purpose of the paper is to analyze the bearing capacity of hydrostatic bearing during the change of film thickness under different working conditions and to improve the processing efficiency and precision of equipment.Design/methodology/approachIn this study, Q1-205 double rectangular cavity hydrostatic thrust bearing is selected as the research object. The dynamic mesh method and ANSYS/FLUENT software are used to simulate the curves of oil film thickness and oil pressure under different operating conditions. Finally, the change of pressure in the oil cavity at different operating speeds under a certain inlet flow rate was tested through design experiments.FindingsWhen the film thickness was thick, the maximum pressure in the oil cavity at different inlet velocities showed little difference. With a larger inlet flow, the maximum pressure in the oil cavity was higher. The pressure at the edge of the oil seal was linearly distributed. The oil pressure in the downstream side was greater than that in the counter flow side. When the working pressure was low, the pressure in the oil cavity slightly decreased with the increase of working speed. Moreover, the pressure loss at high speed was considerable.Originality/valueBased on the lubrication theory, the mathematical model of the bearing oil film was set up. The bearing capacity equation of the hydrostatic cavity was derived. The double-rectangular-annular hydrostatic guides studied in this paper have not been reported in previous research literature and the method of dynamic mesh dynamic simulation of variable viscosity is seldom studied before. The bearing characteristics and the change of oil film thickness under different working conditions have been studied systematically and comprehensively. The theoretical analysis results are basically consistent with the experimental results.

Modal Analysis and Optimization of Typical Parts of 2K-V Reducer

As a new type of high-precision gear transmission mechanism, the transmission accuracy of the 2K-V reducer will be greatly affected by vibration. With the RV110E reducer as the research object, a three-dimensional model of the needle wheel is established. Using the finite element analysis software, the natural frequency and mode shape of the needle wheel are calculated, when it’s under the output condition, then compared with the calculated gear meshing frequency. It is found when the needle wheel is used as an output, the vibration frequency is within the gear meshing frequency range, which is easy to cause resonance, thereby affects the transmission precision of the whole machine. The part of the outer shell of the needle wheel and the oil seal of the skeleton is the weakest and prone to deformation. By adding 6 reinforcing ribs between the needle wheel flange and the outer casing, increasing the flange outer diameter at the same time, the natural frequency can be increased, the deformation concentrated region can be transferred to the outer casing and the reinforcing rib. The connected parts avoid resonance and increase the service life of the needle wheel.

Numerical and Experimental Investigation of the Sealing Effect of a Specific Labyrinth Seal Structure

A numerical simulation and experimental study were performed to investigate the sealing effect of the labyrinth seal used in a wheel-side reducer. A three-dimensional computational fluid dynamics model was established based on the labyrinth structure. The effects of the temperature and viscosity of lubricant, rotor speed, pressure ratio, clearance, and cavity size of the sealing structure on the sealing were analyzed, and the leakage amount under the corresponding values of different factors was also analyzed. The results indicated that increase in the lubricating oil temperature, viscosity, pressure ratio, and seal clearance lead to decrease in the sealing effect and increases in the leakage. And the effect of rotational speed on the seal is low. To verify numerical simulation, the results of numerical analysis, a test bench was set up to simulate the work of the reducer, and the sealing effect of the sealing structure was examined. The simulation result was compared with the actual results. Both the numerical simulation and experiment indicate that the labyrinth seal achieves the desired sealing effect.

Research on the oil film temperature field of hydrostatic bearing with variable viscosity dynamic simulation and experiment

In order to improve the lubrication performance of the double-rectangular cavity hydrostatic thrust bearing, this paper selects the temperature rise characteristics of hydrostatic bearing as the research object under the conditions of changing oil film thickness and different working conditions. Using the dynamic mesh method with variable viscosity dynamic simulation, the changing temperature rise curves under different inlet flow velocities and rotating speeds are obtained. This paper obtains the changing laws of oil film thickness and temperature under the hydrostatic bearing running in no-load, load 2.5 t, load 10 t and the rotating speeds of 40 r/min, 60 r/min and 80 r/min. Under the low rotating speed, the high temperature region in the oil cavity mainly concentrates on the counter flow side. With the increase of working speed, the high temperature region on the counter flow side expands to the oil seal side obviously. When the oil film thickness was in the range of 0.04 mm to 0.07 mm, the temperature of oil seal edge increased with the increase of the inlet flow velocity. Using the FLUENT software, the variable viscosity simulation of hydrostatic bearing is carried out under different oil film thickness, and the temperature distribution of oil cavity is obtained. Finally, the correctness of theoretical analysis and simulation are verified by conducting experiment.

Innovative Design of the Cooling Topologies for Electric Vehicle Motors

According to the different cooling medium, the electric motor cooling styles can be divided into liquid cooling and air cooling; the former involves water cooling and oil cooling while the latter comprises natural air cooling and forced air cooling. Whereas, the air cooling system is difficult to meet various performance requirements for the modern Electric Vehicle (EV). Therefore, approximately all EV motors are liquid cooled at present. Moreover with the trend of EV motors to Permanent Magnet (PM) and to high speed, for instance, the maximum working rotated speed from 10,000rpm to 20,000 rpm, the packaging of the motor is minimized at same power while efficiency drops, lifetime shorten and even cause demagnetization due to thermal effects without optimum design. Consequently, the improvement of the liquid cooling system is essential to enhance the efficiency of the EV motor in the future for higher power density. In this perspective, the innovative cooling topologies of electric machines based on the development results of the parts such as lubricating oil and motive seal of electric vehicles are presented in this paper. It solves some problems brought about by predecessors in view of the high efficiency and reliability of the motor with higher energy density.

Study and Optimization of Structural Parameters of Oil Seal by Response Surface Method

The effect of structural parameters such as contact width, low-angle, high-angle, interference and waist depth on the sealing performance of rotary lip seal was analyzed by finite element method. Based on the macroscopic pumping effect model of the rotary shaft lip seal and the pumping rate equation, the influence of structural parameters on pumping rate was calculated and analyzed. The structural and operational parameters of lip seal were optimized by the response surface method. 32 kinds of the model were made by compounding levels on each factor, and the response surface regression characteristics of each model are analyzed. The results show that low-angle, high-angle and interference are the main factors that influence significantly the seal performance of rotary shaft lip seal, and contact width, low-angle and high-angle are major influential factors for pumping effect. Therefore, these factors are considered as the most important factors for an optimum design of the rotary shaft lip seal. The optimal conditions are obtained, and the results are also verified by analytical methods.

Novel Carbon Black-Halloysite Nanotube Reinforced NBR-PVC Hybrid Oil Seals for Automotive Applications

Novel Carbon Black-Halloysite Nanotube Reinforced NBR-PVC Hybrid Oil Seals for Automotive Applications

Leakage performance of labyrinth seal for oil sealing of aero-engine

Experimental investigation has been done to evaluate the leakage performance of labyrinth seal for oil sealing on high-speed sealing test rig at different working and geometric parameters. Typical values of pressure ratio ranging from 1.0 to 2.0 were used and the rotating speed varied from 0 to 30,000 rpm. Dimensionless Taylor number was invited to response the effect of rotation. Oil was injected at the rate from 1.2 L/min to 2.8 L/min to check the sealing capacity. Leakage was measured at different seal configurations including sealing clearance, tooth tip thickness, pitch, teeth number, front inclined angle and oil-throwing angle. Different from gas sealing, the application of oil-throwing tooth in oil sealing attracted much interest as an obvious alternative to the conventional labyrinth seal. A blocking ring was captured during testing, which establishes understanding of underlying flow mechanisms in the clearance and plays an important role in oil sealing. There is a critical Taylor number at which the leakage coefficient drops drastically. After the critical Taylor number, a parabola rule appears. An optimal composition of tooth tip thickness, teeth number, oil-throwing angle and front inclined angle exists where the leakage performance behaves better.

高温高速油封新试验评价装置的设计与研究

高温高速油封新试验评价装置的设计与研究

Simulation and experiment on pressure field characteristics of hydrostatic hydrodynamic hybrid thrust bearings

PurposeThis paper aims to improve the bearing capacity of hydrostatic thrust bearing under working conditions of high speed and heavy load; a new wedge-shaped structure opened on an edge of oil seal is put forward, the loss and insufficiency for hydrostatic bearing capacity are made up by using dynamic pressure, and then, hydrostatic hydrodynamic lubrication is realized.Design/methodology/approachOil film three-dimensional models of unidirectional and bi-directional hydrostatic hydrodynamic oil pad are established by using UG. The oil film pressure fields of two kinds of oil pad are simulated by using ANSYS ICEM CFD and ANSYS CFX; the pressure fields distribution characteristics are obtained, and the effects of workbench rotary speed and bearing weight on pressure field are analyzed. Also, the experimental verification is made.FindingsThe results demonstrate that with an increase in workbench rotary speed, the oil film pressure of two kinds of hybrid oil pad increases gradually, and the maximum pressure of the bi-directional one accounts for 95 per cent of the unidirectional one when the load is constant. With an increase in load, the oil film pressure of two kinds of hybrid oil pad increases gradually, the difference between them is 9.4 per cent under the condition of load of 25 t when the rotary speed is constant.Originality/valueThe paper can provide theoretical basis for a structure design of hybrid thrust bearing under different rotary speed and load conditions, and compensate the shortage of static pressure-bearing capacity by using dynamic pressure, improve the stability of vertical CNC machining equipment.

Hydrated Seal Lip for Live Center in Machine Tools

When performing a cutting operation, a water-soluble cutting fluid may be used for cooling. Labyrinth and oil seals are commonly used in the rotating centers of machine tools to prevent the cutting fluid and dust from entering the inner parts. However, these seals do not demonstrate adequate functionality in a water-based environment. Therefore, a new rotary shaft seal was devised to separate the water-soluble cutting fluid from interacting with air. The rotary shaft seal was made from polyvinyl formal (PVF). Because PVF is a hydrophilic material, it is expected to provide suitable functionality as a seal in a water-based environment. Performance evaluations of PVF and oil seals were experimentally obtained and compared from the point of view of frictional torque, water-soluble cutting fluid leakage volume, and service life as a seal.

Studies on the mechanical properties of carbon black-halloysite nanotube hybrid fillers in nitrile PVC nanocomposites for oil seal applications

The International Scientific Research Organization for Science, Engineering and Technology (ISROSET) is a Non-Profit Organization; The ISROSET is dedicated to improvement in academic sectors of Science (Chemistry, Bio-chemistry, Zoology, Botany, Biotechnology, Pharmaceutical Science, Bioscience, Bioinformatics, Biometrics, Biostatistics, Microbiology, Environmental Management, Medical Science, Forensic Science, Home Science, Library Science, Material Science Military Science, Physical Science, Physical Education Science, Educational Science, Fisheries, seed technology, Agriculture, Forestry Science, Mathematics, Physics, Statistics and Geology/Earth Science), Computer Science, Engineering and Information Technology, Commerce, Management, Economics Sociology and Social Science.

An investigation to detect leakage of oil using wear debris analysis in journal bearing of 1 MW hydel power plant

In the hydel power plant a small leakage of water is comman hence it is difficult to detect the leakage of oil from naked eye. The leakage of oil is experienced by the level indicator of oil tank. Based upon the complain of decreasing oil level in the oil tank frequently, it is decided to monitor the whole oil channel as well as bearing on the periodic basis. In the monitoring process, Wear particle analysis as well as temperature of oil inside bearing and pressure of oil inside the bearing was considered. wear debris was filtered using vacuum pump and filter paper and then it is analyzed based upon their aspect ratio(Major length/Minor length), its color and the length of particle. It is found in investigation that there are (non metallic wear (irregular and large) that can be co- related with oil seal. It is investigated that the leakage of oil is mainly because of wear and tear of oil seal.

Performance analysis of high-stiffness bearing composited by hydrostatic cavities and tilting pads with preload

PurposeTo meet the high stiffness requirement of bearings used in high-precision spindles, this paper aims to propose a novel kind of bearing composited by hydrostatic cavities and tilting pads with preload.Design/methodology/approachCavities are cut on the oil seal surface of a hybrid bearing, in which the tilting pads are set up. The load of the bearing is carried by the hydrostatic cavities and tilting pads. The structural features of this compound bearing and the controlling variables of the main stiffness coefficient are presented. Two basic design principles are proposed on the basis of equal machining clearance (EMC) and equal installation clearance (EIC).FindingsThe theoretical analysis indicates that the stiffness of compound bearings under the EMC condition increases to infinity monotonously when the preload coefficient of the tilting pad tends to 1, while the stiffness under the EIC condition has a peak value. Therefore, a synthetic design principle is proposed by synthetically using the above-mentioned two principles. The applicable range of the three principles is discussed through an example.Originality/valueThe study about technological combination of hydrostatic cavity and tilting pad in this paper can provide suggestions for the design of a high-stiffness bearing in a precision spindle.

Release of the stuck drill string by the method of frictional self-oscillations

The mechanism of generation of forces, holding the drill pipes in case sludge sedimentation, caving in and collapse, as well as buckling and flow of plastic rocks, formation of oil seals was described. The modern ideas about friction forces were reviewed. A mathematical model of frictional self-oscillations for release a stuck drill string was developed. The necessity of application a vibration smoothing method of generating self-oscillations during emergency was substantiated. Using the computer program, parametric calculations of velocity change of the stuck drill pipe release were made. The author conducted numerical studies of the drilling line speed impact and oscillator frequency on the efficiency the sticking elimination process.

Cure, Mechanical and Swelling Properties of Biocomposites from Chicken Feather Fibre and Acrylonitrile Butadiene Rubber

Biocomposites of acrylonitrile butadiene rubber (NBR) reinforced with chicken feather fibre (CF) were prepared using dicumyl peroxide (DCP) as vulcanizing agent. Composites with three series of chicken feather fibres were studied i.e., raw (RCF), sterilized (SCF) and alkali treated (ACF). The cure characteristics of composites were studied. The mechanical properties of NBR were found to be improved by the incorporation of chicken feather fibre in all forms. Surface modification of the fibre was done by alkaline treatment to improve the interfacial adhesion and it characterised by FTIR. Better properties are shown by the composites with ACF. The swelling behaviour of the composites in N,N-dimethylformamide, acetonitrile, dimethyl sulfoxide and water were analyzed for the swelling coefficient values. The biodegradable characteristics of CF reinforced NBR composites were studied by soil burial test which indicated that it is an eco-friendly and acceptable material. Scanning electron microscopy studies support the results of mechanical properties. The outcome obtained from this study is believed to assist the development of environmentally–friendly composites especially for specific product applications like oil seals, hoses and automobile bushes etc.

Low-friction shaft seal composed of bio-inspired materials covering low-speed range under water environment

Shaft seals with a seal lip are used in various applications to separate gases and fluids, but their sealing function and durability are affected by the extent of lubrication at the dynamic seal faces between a rotating shaft and the seal lip. A new sealing system consisting of two hydrated seal rings and non-Newtonian lubricants was designed by a biomimetic approach to minimise frictional loss and provide high waterproof function when separating air and water. This system demonstrates significant superiority in low-speed rotation, conditions under which the lubrication mechanism of an oil seal or mechanical seal does not generally work well. Fibre reinforcement of the seal ring material was performed to prevent the deformation of the soft seal rings because of the frictional force in the tangential direction of the shaft and water pressure. This reinforcement enabled the new sealing system to obtain both high waterproof performance and low frictional characteristics in the speed range of 20–100 r/min.