Victorian Institute of Engineers
(Founded 1883, Incorporated 1926)
1947, JULY 24TH PROCEEDINGS
Minutes of General Meeting of the Victorian Institute of Engineers, held in the Radio Theatre, Melbourne Technical College, Melbourne.
In the absence of the PRESIDENT (MR. W. H. DOBSON), the Council nominated, and it was agreed that, Mr. L. L. PEMBERTON occupy the chair.
(Roth Vice-Presidents were, unfortunately, unable to attend.)
Apologies for non-attendance were received from Messrs. W. H. Dobson, B. J. L. Bremner, V. R. McKay, Geo. D. Thompson, G. E. Gamble and E. J.
McDonald.
The minutes of meeting held 26th June, 1947, were read and approved.
Correspondence was reviewed, and general announcements made.
A ballot for election as Member of Mr. N. G. Daws, and Junior Member Of Mr. R. N. Cox, was conducted.
A Lecture was given (freely illustrated with diagrams and specimens) by Mr. N. SAG, Degree Mech.E. (Budapest University), Senior Lecturer in Machine Design, Melbourne Technical College, on "PRINCIPLES OF GEAR TOOTH CORRECTION."
Discussion ensued.
Ballot was declared in the affirmative for both candidates.
Meeting concluded with light supper.
PAPER
FUNDAMENTAL PRINCIPLES OF MODERN GEAR DESIGN PRACTICE
BY NICHOLAS SAG, Degree Mech.E. (Budapest Univ.).
Senior Lecturer in Machine Design (Melb. Tech. College).
1947.
INTRODUCTION
To ensure constant gear ratio at any instant, tooth profiles used for gearing must fulfil certain conditions.
In Fig. 1, 01 and 02 represent the centres of two mating gears, and the tooth Profiles are shown in contact at point Q. The momentary motion at this instant in the direction of the common normal C1C2 and the instantaneous velocity in this direction is denoted by V. Then the angular velocities can be expressed as
w1 = - and w2 = V V
Where rl and v2 are the distances of centres 01 and 0,from the common normal of ri the tooth profiles. The condition to be satisfied is
wl =const.
w2 But
col v2 02P
= = OlP = const.
w271
