• Florian Ion Petrescu Bucharest Polytechnic University
  • Relly Victoria Petrescu Bucharest Polytechnic University



The paper presents an original method to determine the efficiency of the gear, the forces of the gearing, the velocities and the powers. The originality of this method relies on the eliminated friction modulus. The first chapters are analyzing the influence of a few parameters concerning gear efficiency.  These parameters are:  z1   - the number of teeth for the primary wheel of gear; z2   - the number of teeth of the secondary wheel of gear; alpha0 - the normal pressure angle on the divided circle; beta - the inclination angle. With the relations presented in this paper, it can synthesize the gear’s mechanisms. Today, the gears are present everywhere, in the mechanical’s world (In vehicle’s industries, in electronics and electro-technique equipments, in energetically industries, etc.). Optimizing this mechanism (the gears mechanism), we can improve the functionality of the transmissions with gears. At the gear mechanisms an important problem is the interference of the teeth. To avoid the interference between teeth, we must know the minimum number of teeth of the driving wheel, in function of the pressure angle (normal on the pitch circle, alpha0), in function of the tooth inclination angle (beta), and in function transmission ratio (i). The last chapter presents an original method to make the geometric synthesis of the gear, having in view the minimum number of teeth of the driving wheel. The classical methods use many different relations to determine the minimum number of teeth of the driving wheel. By this paper we want to give a unitary method to determine the minimum number of teeth of the driving wheel 1, to avoid the interference between the teeth of the two wheels (of the gear).


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Biografia do Autor

Florian Ion Petrescu, Bucharest Polytechnic University

Nihil sine Deo

Ph.D. Eng. Florian Ion PETRESCU
Senior Lecturer at UPB (Bucharest Polytechnic University).

Citizenship: Romanian;
Date of birth: March.28.1958;
Higher education: Polytechnic University of Bucharest, Faculty of Transport, Road Vehicles Department, graduated in 1982, with overall average 9.63;

Doctoral Thesis: „Theoretical and Applied Contributions About the Dynamic of Planar Mechanisms with Superior Joints”.

Expert in Industrial Design, Engineering Mechanical Design, Engines Design, Mechanical Transmissions, Dynamics, Vibrations, Mechanisms Machines Robots and Mechatronics.


Languages known:
-French; -English.

Related activities and functions:

Instructor and Social Commission Head of CUB (Bucharest’s University Center) 1985-1987, the Third Head of CUB after [Moncea] and Bostan, 1985-1987.