• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.5
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• pp.572-578
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• 1985

A composite gear with involute-circular are tooth profile and a tooth profile of the rack to cut this gear are theoretictically obtained. The composite gear has involute tooth profile in the vicinity of pitch point and has circular arc tooth profiles at addendum adn dedendum. The contact ratio(M$_{c}$), chordal tooth thickness (chordal tip tooth thickness S$_{t}$, chordal root tooth thickness S$_{t}$) of the composite gear are compared with those of involute gear. When module, number of teeth and pressure angle eqaul, S$_{t}$ of composite gear is much larger than that of involute gear. Under the same conditions, S/sib t/ and M$_{c}$ of composite gear become smaller than those of involute gear.lute gear.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.1
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• pp.1-10
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• 1993

A design method of gear tooth profile which can reduce the noise of gear is studied. The tooth profile is generated by combining involute and cycloid tooth curves in which the involute tooth profile is near the pitch point and cycloid tooth profile at the addendum and the dedendum. Considering parameters which have an influence on the reduction of gear noise and building up a design conditions for the noise reduction of gear, the lower-noise combined gear tooth profile is designed. For the check of noise reduction of the combined gear profile, two pairs of combined profile gear, two pairs of involute gear, and a pair of cycloid gear were manufactured by the NC Wire Cutting Machine, and the experiment for measuring of gear noise was carried out on each pair. The noise reduction of the combined profile gear was obtained.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.6
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• pp.870-875
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• 1986

In this study, full-rounded tip curve of rack and its mating fillet curve of pinion in Involute-circular arc composite tooth profile are derived. Mechanical characteristics are calculated analytically, i.e., Specific sliding, Nominal bending stress at working root circle and the Contact factor of the arc of contact in circular arc part to the arc of double contact. These characteristics compared with standard involute tooth profile are improved in circular arc part of composite tooth profile. To obtain more efficient composite tooth profile, we studied these characteristics with regard to the changes of unwound angle and radius of circualr arc. And a design method of composite tooth profile is suggested. Composite tooth profile are compared with standard involute tooth profile.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.2
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• pp.296-303
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• 1987

The composite gear which is composed of involute curve and circular arc has been studied. In the vicinity of pitch point, its profile is an involute curve, and in the dedenum, a circular arc. The curve in the dedendum is generated by the circular arc of the mating gear. Though the available range between minimum and maximum radius of circular arc can be given by existing tooth profile equation, there was no formulation which relates design parameters to the desired radius. It is attempted to get the formula for the radius of circular arc as a function of design parameters, such as unwounded angle, number of teeth, module, and pressure angle. The radius of circular arc, the chordal tooth thickness at working root circle, nominal bending stress, Hertz stress and contact ratio obtained from derived formula are compared with those of the existing design criteria. And these are compared with those of involute gear.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.2
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• pp.198-204
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• 1987

In a new involute-circular arc tooth profile which is composed of an involute curve in the vicinity of pitch point, a circular arc in the addendum part, and a curve in the dedendum part which is generated by the circular arc profile of mating gear tooth profile, the tooth contact stress is calculated analytically and the root fillet stress is calculated by the finite element analysis. The root fillet stress and the Hertzian contact stress of composite tooth profile gear are decreased with increasing the pressure angle and with decreasing the radius of circular arc and unwound angle. Compared with the standard involute gear, the root fillet stress is decreased by 2-15% and the Hertizian contact stress is decreased by 6-24%.