Design, Manufacture, Construction and Tests of a Reduced FZG Tribometer with
Dynamic Load Variation
mechanical design, mechanical fabrication, assembly of mechanical systems, gears
tribology, FZG test.
The widespread use of gears in the industrial productive sector provides
engineering solutions for power transmission problems and leads scientific researches
in mechanical engineering o improve the efficiency of gearboxes by reducing the wear
and the friction between the gear. The improvement of the lubrication is one of the
ways to reduce friction and wear between the gears. Thus, this work aims to build and
test a tribometer capable of reproducing the contact between cylindrical spur gears in
order to promote wear on their teeth. The conceptual design was based on the
tribometer of the DIN ISO 14635-1: 2000 standard, which consists of the transmission
of power between two gearboxes interconnected by two parallel axes in the
back-to-back power recirculation format. The project has: (a) a loading system with
standard weights that aims to accelerate the wear on the gear teeth by applying torque
to the system by means of a caliper-disk brake system; (b) a rigid base of structural
aluminum profiles that has good rigidity and flexibility for expanding the tribometer in
the future; (c) a mechanical torque limiter with torque preload in order to ensure gear
engagement; and (d) an electrical system controlled by a programmable frequency
inverter. The projected components were manufactured at UFRN or purchased on the
market and, subsequently, were assembled at UFRN. After assembly, the tribometer
underwent a pilot test which aimed to: (i) verify the induction to wear on the teeth of
the gears with the aid of microscopic images; (ii) map the machine's working
conditions and variables; and (iii) optimize working conditions for the full functioning
of the tribometer. The rotation and loading parameters were varied at three different
levels each, configuring a 3² factorial study. Three response variables were measured:
electric motor current, motor torque and brake disc temperature. The results were
analyzed with the aid of the response surfaces method for the optimization of the work
parameters and obtained satisfactory results for the conduct of new studies.