Design and Fabrication of a Planetary Gearset as Part of a Hybrid Powertrain

Abstract

Students at the Rowan University department of Mechanical Engineering have been assigned a long-term, large-scale design/build project in order to study the effects of integrating the curriculum on subject matter retention and design efficacy. The project, a bench-scale hybrid electric powertrain system, is designed, analyzed and fabricated by students in six modules, starting in their sophomore year and culminating in their final semester as seniors. This complex project has been selected in order to integrate the core mechanical engineering courses: Mechanical Design, Thermodynamics, System Dynamics and Control, and Fluid Mechanics. A bench-scale hybrid-electric vehicle powertrain has sufficient complexity to involve all Mechanical Engineering disciplines and the simplicity to be built by students over the course of five semesters. The research is designed to test two hypotheses:1. A long-term design project that integrates knowledge from multiple courses strengthens student knowledge retention. 2. A large-scale design project requiring tools from many courses improves student problem-solving and design skills.By integrating five semesters of the mechanical engineering curriculum into a cohesive whole, this project has the potential to transform the way undergraduate education is delivered. Before and after testing is being conducted to assess: a) Change in retention between courses and b) Change in student problem-solving and design skills.The centerpiece of the hybrid powertrain is the planetary gearset, which combines power from the air engine and electric motor to produce the desired output speed at the wheels. During the fall semester of their Junior year, the students design and fabricate a small planetary gearset, and conduct tests to assess its performance. The planetary gearset project is conducted in Machine Design, a core mechanical engineering course. This paper describes the planetary gearset assignment only -a description of the full hybrid powertrain project is given the papers listed in the References. Based on student feedback, an overwhelming majority of the students felt that the "hands on" project was valuable in the Machine Design course and enjoyed working on the project.Page 26.450.2

Sensing and Control Electronics for a Benchtop Hybrid Powertrain

“…The focus of this paper is the set of electronic circuitry needed to sense and control the powertrain. This is the latest installment in a series of papers discussing the project; see [2][3][4][5][6] for a fuller description.…”

“…Students at Rowan University design and fabricate a bench-scale version of the Toyota Hybrid System over the course of five semesters, as a way of integrating the mechanical engineering curriculum. Parts of this project have been described in earlier papers [2], [3], [4], [5] and only a short background will be given here. A wealth of information about the project is available on the author's website www.benchtophybrid.com.…”

“…The focus of this paper is the set of electronic circuitry needed to sense and control the powertrain. This is the latest installment in a series of papers discussing the project; see [2][3][4][5][6] for a fuller description.The "prime mover" in the benchtop hybrid is a small engine powered by compressed air, which is designed and fabricated by students during their Junior year. The goal of the powertrain is to convert the maximum amount of energy stored in the compressed air to motion at the output shaft of the powertrain.…”