• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.5
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• pp.165-172
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• 2001

Wheel bearing units were almost exclusively used for car front wheel, where the two ball rows are directly side by side with integrated rubber seal. The seal is of important for wheel bearing units due to the adverse environmental conditions with mud and splash water. The seal of wheel bearing units was designed to have geometry with multi lips, which elastic lip contacts and deforms with bearing. The equation of reaction force for deformed lip as cantilever beam was previously used for seal lip design. But it's result was not useful because deflection of the beam differs from lip's. In this study, deformed shape of the lip was assumed to and order function which is more similar to lip deformation and made the equation for reaction force prediction. The Reaction forces from each other equations were compared with results by FEA to prove usefulness of new equation.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.3
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• pp.233-241
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• 2015

The aim of this study was to determine the bite force and lip closing force in preschool children and to analyze the correlation between these forces by age, height and weight, respectively. Data were obtained from 98 children (56 males, 42 females) ranging from 3 to 6 years of age. The magnitude of the bite force was measured bilaterally corresponding with the 2nd primary molars using a bite force gauge, $GM10^{(R)}$ (Nagano Keiki) and the force of lip closure was measured using LIP DE $CUM^{(R)}$ (Cosmo Instruments). The averages of bite force for boys and girls were 217.69 N and 205.05 N, respectively. The relationship between bite force with age, height, and weight present significant positive correlation (p < 0.001, p < 0.001, and p < 0.001, respectively). The averages of lip closing force for boys and girls were 4.81 N and 4.07 N respectively. The relationship between lip closing force with age, height, and weight present significant positive correlation (p < 0.001, p < 0.001, and p < 0.001, respectively). No significant differences were observed between boys and girls (p > 0.05) in both forces. A significant correlation was observed between lip closing force and bite force (p = 0.002).

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.10a
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• pp.158-162
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• 1996

A split shaft device is commonly used to measure the radial force of lip seals. The radial force measured with this device includes some inevitable error. This error is caused by the fact that the split shafts cannot maintain a perfect circle when the interference becomes larger or smaller than some initial interference. In this study, a theoretical model for the calculation of the radial contact force has been carried out, and an explicit equation for the measurement error as a function of the initial interference and the interference to be measured has been obtained. The error when the interference is small is not dependent upon the material properties and the shape of the lip seal, but rather upon the amplitude of the initial interference and the interference to be measured. When the interference is larger or smaller than the initial interference, the measured contact force is always underestimated or overestimated.

• Tribology and Lubricants
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• v.9 no.1
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• pp.32-37
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• 1993

The equations are derived for the evaluation of the axial contact forces. The contact forces of rubber seals are analyzed as a function of the ratio of real contact length, the thickness of seal lip, the inclined angle of seal lip, and the interference between the edge of seal lip and the rotating inner ring. The experimental apparatus is developed for the test of seal lip contact force. The data for designing rubber seals are presented in terms of the ratio of real contact length, initial inclined lip angle, lip thickness. and the interference. The results obtained from the derived equation for the contact force are in good agreement with the experimental results.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1559-1566
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• 1994

Using the finite element method, the contact force, contact band width and temperature distribution of lip seals analyzed for the interference including some nonlinearities such as material nonlinearity, geometrical nonlinearity and nonlinear contact boundary condition. The calculated results showed that the contact stress concentrated on the contact zone between the garter spring and the rubber toward the flex side, the contact edge of lip seals. The high contact forces due to the increased interference separate the sealing gap between the lip edge and the rotating shaft. This may lead to leak the sealed oil.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1576-1580
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• 2007

Typical lip seals are widely used as sealing mechanism of rotary and reciprocating shaft. Double lip seal has comparatively high stiffness and dynamic radial eccentricity. Usually material of these seals is made of elastomer and nonlinear finite element analysis is required to analyze behaviour of this material because Young's modulus is varied with working load. In this paper, MSC MARC/MENTAT is used for nonlinear analysis of double lip seal with pressure variation and interference. The contact normal force of double lip seal between lip and shaft is analyzed to reduce power loss when shaft rotates.

• Tribology and Lubricants
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• v.10 no.4
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• pp.82-88
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• 1994

This paper deals with a FEM computation as well as measurement of the contact force and distribution of the temperature in rubber lip seals when the sealing interference between the rotating shaft and the lip edge is present. The study of the contact forces and distributions of the temperature and the sealing contact stress has always been one of the basic steps in the process of designing a lip seal. The calculated FEM results indicate that as the sealing interference increases, the contact force moderately increases compared with decreased sealing interference at the seal lip edge and radically increases the contacting width. And the FEM computation of oontact forces including nonlinear problems has been compared with experimental measurements with good agreement. The frictional heat does not dissipate promptly in the rubber seal lip and tends to accumulate at the contacting lip edge especially.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.12
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• pp.2261-2267
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• 1992

The equations are derived for the evaluation of the axial contact force. The contact forces for rubber seals are analyzed as a function of the ratio of real contact length, the thickness of seal lip, the inclined angle of seal lip, and the interference between the edge of seal lip and the rotating inner ring. The design data for rubber seals are presented in terms of the ratio of real contact length, initial inclined lip angle, lip thickness and the interference. The calculated results show that the deflected interference and the circumferential stress cause considerable change of contcat forces for the low sealed pressure.

• The Journal of the Korean dental association
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• v.47 no.10
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• pp.656-668
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• 2009

It is difficult to perform orthodontic treatment for cleft lip and palate patient. Although there are many orthodontic appliances to expand narrowed maxillary arch, results are rarely successful and the possibility of relapse is increased due to severe scars. Self-ligating bracket, recently used in orthodontic treatment, suggests solution of crowding by expansion of dental arches. Light and continuous force could apply for orthodontic movement due to characteristic low friction of self ligating bracket, which gives expansion force until dentition reaches its new equilibrium position and it can be expressed as spontaneous lateral expansion with heavy labial tension. This kind of expansion force is thought to be a possibility of expanding the constricted maxillary arch of cleft lip and palate patient. Repositioning of the maxilla by Le Fort I osteotomy in case of severe maxillary deficiency, increases the possibility of relapse because of limitation in anterior movement and adaptation of soft tissue. In these cases, distraction osteogenesis(DO) can be applied for stable result. We report a case of cleft lip and palate patient with narrowed maxillary arch and maxillary deficiency using self ligating bracket and DO.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.7166-7175
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• 2015

This paper is a study on using gas springs for reduced friction in the elevation of the large television stand. Target is applied to the operation of the elevation over 50-inch television that uses a gas spring. Gas seal lip technology is needed for development acting on the piston rod in order to obtain a reduction in friction in elevation operation. In order to acting on the gas seal lip technology, the improved friction force can be obtained through the inner diameter of gas seal lip, the design of cutting angle and the changes of material.