• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1995년도 춘계학술대회논문집
• /
• pp.41-53
• /
• 1995

Forging of spur gears has been investigated by means of upper-bound method. The term forging means forging of spur gears with solid cylindrical billets, hollow billets with flat punch. Kinematically admissbile velocity field for forging of spur gears has been proposed in this study. The 1/2 pitch of spur gear has been divided into seven dieformation regions, wherein, an involute curve has been introduced to represent the shape of die profile. Especially neutral surface has been introduced intor forging of hollow gears from hollow billets. By using the kinematically admissible velocity field, the powder requirements and suitable conditions for forging fo spur gears were successfully calculated with numerical method. According to the analysis , the acceptable number of teeth for forging of spur gears is from 15 to 20.

• Tribology and Lubricants
• /
• 제4권2호
• /
• pp.28-35
• /
• 1988

A general and efficient algorithm is proposed for the analysis of the frictionless elastic contact problems. It utilizes a simplex-type algorithm with a modified entry rule and incoporates finite element method to obtain flexibility matrices. The algorithmic solution is compared with the Hertzian solution for the contact problem between two cylinders to prove its accuracy and the contact problem between pin and piston rod is solved and compared with the numerical results of Frankavilla and Zienkiewicz to demonstrate the generality and effectiveness of the suggested algorithm. The contact problem between mating involute gear teeth at the worst load position is considered. The computed contact stress is smaller than the result of Hertz's theory applied to the contact between two kinematically equivalent discs and the contact area is larger than that of Hertz's theory.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 춘계학술대회 논문집
• /
• pp.460-463
• /
• 2005

Gear is an important machine element to be used transmission in case short between axis. We drew gear using automatic design program to solve problem when it draw gear. We manufactured gears that it have different pressure angles using W-EDM. And we got a 2D profile of manufactured gear using reverse engineering. So we got to manufacturing error in comparison with CAD data and measured data. In result we could manufacture precise gear through improvement of manufacturing processes.

• 한국기계가공학회지
• /
• 제10권2호
• /
• pp.52-60
• /
• 2011

Korea is the best country for ship-building. But nowadays, the speedboat and yacht are not mostly developed yet. For the sleek lines of ship, more innovative transmission system should be obtained in the ship industry. In general, marine transmissions often use the straight shafts and the helical gears. So it makes problem that engine-room requires large space. In this case, conical gear is the best solution for this. Until now, technology of conical gear is not generalized, but it will be increased more through many applications. So, in order to get conical gear design technology by ourselves, this thesis is conducted. This paper was written to gain useful information of marine gearbox design applied conical gear through the measurement of backlash, computer analysis and tooth contact test of helical conical involute gear pairs.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2002년도 제35회 춘계학술대회
• /
• pp.200-206
• /
• 2002

Pressure and film thickness of contacting surfaces between teeth of the involute spur gear in lubricated condition were studied by a numerical method. Dynamics of the gear and pinion was considered to gel ail accurate initial clearance between gear teeth. The 3-dimensional non-steady elastohydrodanamic lubrication analysis on the gear teeth showed a slight higher pressure at the inlet region of the contacting face as well as pressure spike at the outlet region and a more thick film thickness than that of steady condition.

• Tribology and Lubricants
• /
• 제5권2호
• /
• pp.107-112
• /
• 1989

This paper deals with strength analysis of tooth and method of manufacture of external tooth profile in harmonic drive. From the calculation of load imposed on the contact teeth, moximum contact stress is investigated to design the addendum modification coefficient. New tooth profile of the external gear is generated according to the law of gearing, assuming that internal gear has involute tooth profile. External tooth profile can't be manufactured by conventional exclusive tools which have pressure angle of 20$\circ$. The method to design cutter tooth profile is presented.

• Tribology and Lubricants
• /
• 제4권2호
• /
• pp.60-67
• /
• 1988

Conventional theory of gear mechanism can't be applied to analyze the harmonic drive due to specific movement of the teeth. This paper deals with an analysis of kinematics and geometry of the tooth engagement of a harmonic drive comprising circular spline, flexspline and wave generator. A theoretical new tooth profile of the flexspline in meshing internal rigid gear with involute profile is obtained. Characteristics of harmonic drive reducer are shown according to parameters such as deviation coefficient, deviation distance, addendum modification coefficient. As an example, the design of harmonic drive with 1:80 reduction ratio is presented.

• 동력기계공학회지
• /
• 제14권3호
• /
• pp.64-70
• /
• 2010

In this study, designing of precise linear transferring device which can be applied to industrial machine and robot industry has been introduced. The direction of power flow and output feature are similar to current Rack-Pinion type. However, unlimited length extensity via rack modulizing, and securing high velocity transportation have been realized by applying Pin-Pinion Gear type at the operation part. The analysis has been calculated to obtain the Pin-Pinion Gear's optimized tooth profile. As a result of research, it is impossible to control precisely even overlap at the teeth of involute and sprocket. Because they have peculiar gearing structure. Therefore, modified cycloid tooth has been proposed to perform high velocity, precise control without backlash.

• 대한기계학회논문집A
• /
• 제20권8호
• /
• pp.2458-2467
• /
• 1996

The rigid-plastic finite element analysis was performed for analysis of ofhot forging and cold sizing of a bevel gear. Two dimensional analysis was carried out to investigate the defect occurrence on vertical symmetric planes during hot forging and three dimensional analysis was to understand the filling behavior on horizontal planes during cold sizing. The involute curve of a tooth was approximated by a circle for convenience in the present analysis. In order to estimate the elastic deformation of the gear and dies during cold sizing, linear elastic finite element analysis was performed. Results of the analysis can be used to predict grain flows and strength distributions in the forged gear, and to design dies and an appropriate preform for the cold sizing.

• 한국기계가공학회지
• /
• 제16권5호
• /
• pp.1-6
• /
• 2017

Gear tooth micro-geometry modifications include the intentional removal of material from the gear teeth flanks, so that the shape is no longer a perfect involute. If the gear shapes are perfect, then the gear tooth meshing is better, therefore the gears will transmit input torque in a more efficient manner without the generation of high frequency engine fluctuation noise. In this paper, we study tooth micro-geometry optimization of rear gear set in 2 speed planetary gear reducers. Analysis revealed problems which are need of modification. Based on the results, tooth micro-geometry was used to deal with load distributions on the rear gear set.