BULETINUL INSTITUTULUI POLITEHNIC DIN IAŞI - Universitatea ...

34 Eugen Străjescu et al.
On the obtained model are choose points on the main edge and on the
secondary one and there are given command for the construction of the planes
in which are measured the requested geometric elements.
3.1. The Determination of the Fellows' Cutters' Geometry.
The fellows' cutters are tools destined to the manufacturing by mortising the
internal and external gear of the spur gears with right, inclined of "in V" teeth,
representing from that reason a high degree of universality, as consequence of
the cutting edges' access in areas inaccessible for other kind of tools (for
example, side mills, hobbing cutters, etc.). Also, the fellows' cutters are the
single cutting tools that can machine cylindrical gear wheels with interior
denture, by rolling.
3.1.1. Geometric parameters. The clearance angle at the tooth' peak presents
a big importance, because from that value depends the bigness of the profile
correction in time after successive sharpening.
Also, by the value of this angle depends the size of the lateral clearance
angle on the two flanks of the tooth that result much more little. So, it is
considered the lateral clearance angle at the level of the divided circ,
respectively if the tooth is cut after the division cylinder, the intersection curve
between this cylinder and the involute clearance angle of the tooth will be a
helix. Because the disposition on the involute flanks of the points in which the
values of the angles α, γ, κ and λ are determined, it results that in any point we
obtain different values that must very between convenient limits.
The actual methods do not permit the determination of these angles, but
3 0 31'
Fig. 3 – The determination of the angles αv and γv at the peak.
2 0