مهندسی مکانیک شریف (May 2018)
DESIGN AND CONSTRUCTION OF MECHANICALLY CLOSED LOOP GEARBOX TEST RIG AND POWER LOSS INVESTIGATION OF THESE SYSTEMS
Abstract
Rotating components are widely used in industries, and it is necessary to test these components periodically. There are several ways to test rotating equipment like using dyno water, air, water brakes, or using a coupled electrical motor and generator. Rigs for implementing these methods can be categorized as closed loop test rigs, and open loop test rigs. For financial, energy consumption, and maintenance reasons using a system with the ability of energy regeneration is suggested. The gearbox test rig with mechanical regeneration of energy, developed in Sharif University of Technology branch of ACECR (Academic Center of Education, Culture and Research), is studied in this paper. This test rig consists of three similar orthogonal gearboxes, test gearbox, two planetary gearboxes (One for inducing torque in the rig and the other for reducing the speed), and an electromechanical motor connected by shafts and couplings and forming a closed-loop. Mechanical components of the rig can be loaded up to 489 Hp at a maximum speed of 3000 rpm, and the test components can be tested in different testing conditions covering variety of torques and speeds. The energy is circulated in the system's loop, and the motor is responsible for compensation of the losses along the loop and also for initiation of the process. Operation of the closed-loop test rig, its losses, application of torque into the closed-loop, and also procedure of controlling the torque and power in the system can be studied by this test rig. This paper contains the conceptual design of the previously mentioned test rig, including the frame work design, control system and torque inducer design, hydraulic system, as well as dynamic and static analysis of the whole system. A formulation is introduced for modeling the system by making use of the equal stiffness and equal inertia. At last, the mentioned formulation is also verified by the system's model in software. The system has also been tested, and the data reveals that the presented test rig is capable of reaching power of 390 kw and the losses are about 10.4\% of the whole energy circulated. Results show that the closed-loop test rigs are the best for the designed power.
Keywords
