Convex Tooth Research Articles

Assembly Interference of Klingelnberg Spiral Bevel Gears.

The assembly interference of the spiral bevel gear of Klingelnberg cyclopalloid system is analyzed on the basis of gear kinematics. There is a case that a pinion cannot be assembled because of an interference of spiral teeth, when the pinion must be pushed in the direction of its axis to assemble in gear box in which a mating gear is assembled previously. This interference shall be designated as 'assembly interference' in this study. The meshing states of pinion outside and gear inside convex tooth surface, together with backlash, determine that the assembly interference occurs or dose not occur. The state of tooth surface is formulated in connection with the pinion rotation angle. And the assembly interference is axamined with the test gears made as a trial. From the examinations, the validity and usefulness of this analysis are confirmed.

Design, Manufacture and Performance of Internal Gear Pumps : 1st Report, Non-Involute Type Pumps for Easy Manufacture

For easy manufacture of internal gear pumps, an internal gear with a convex tooth profile and an external gear, of which tooth-top edge contacts with the convex profile, are used for the gear pumps. Gearing theory of these gears and the theoretical delivery of the internal gear pumps with these gears are clarified. The prominent characteristic found in the gear pumps is that the theoretical torque caused by delivery pressure is zero for the external gear (idler). In practice, a small value of the resistance torque appears on the idler due to viscous friction, etc. It is shown that the resistance torque has no detrimental effects on the tooth surface up to a delivery pressure of about 2 MPa in the present experiments because the Hertzian contact pressure is less than the allowable contact stress of a low hardness steel when the tooth-top edge is rounded to a radius of about 0.5 mm. Six kinds of gear pumps were designed and made by the authors, and almost all characteristics of these gear pumps were clarified by experiments with the support of the theoretical results obtained in the present investigation.