SBIR-STTR Award

Gear Hobbing Predictive Model
Award last edited on: 11/12/2018

Sponsored Program
SBIR
Awarding Agency
DOD : Navy
Total Award Amount
$1,649,885
Award Phase
2
Solicitation Topic Code
N102-122
Principal Investigator
Troy D Marusich

Company Information

Third Wave Systems Inc (AKA: TWS)

6475 City West Parkway
Eden Prairie, MN 55344
   (952) 832-5515
   support@thirdwavesys.com
   www.thirdwavesys.com
Location: Multiple
Congr. District: 03
County: Hennepin

Phase I

Contract Number: N68335-10-C-0448
Start Date: 8/22/2010    Completed: 2/22/2011
Phase I year
2010
Phase I Amount
$149,942
This program will demonstrate the feasibility of innovative physics-based modeling of gear hobbing to predict and improve residual stresses and heat treat distortions while reducing production cycle times and costs of transmission gears. TWS will develop a general, validated, physics-based modeling capability for the gear hobbing process, resulting in detailed chip formation and residual stress prediction. This will be achieved through both a detailed finite element modeling of tool-workpiece interaction, and CNC toolpath-level analysis. The combined outputs of these comprehensive models will provide the ability to predict machining-induced residual stresses and their effects on distortion from subsequent heat treatment, and determine interactions between machining process changes and cost, cycle time and workpiece characteristics. Feasibility will be demonstrated by: 1) advancing physics-based machining modeling for gear hobbing processes, 2) developing physics-based gear hobbing predictive models based on finite element modeling, and 3) validating these physics-based models against machining experiments. Anticipated results results of the program will: (1) predict residual stresses, forces, temperatures, and tooling performance for hobbing; (2) improve fatigue life of gear components through residual stress management while reducing cycle times and cost; and (3) advance knowledge of material removal mechanisms in gear hobbing and their effects on post-machining operations.

Benefit:
Current processes for producing transmission gears involve hobbing or shaping a forged stock to obtain the gear shape. The amount of residual stresses, distortions, and excess material generated during hobbing and following heat treatment processes dictate overall cycle times and component performance. Therefore, it is necessary to understand and control the sources of process cycle times, costs, residual stresses, and distortion to minimize the production costs and improve transmission gear component performance. In contrast to expensive trial-and-error approaches currently used in practice, the proposed Phase I project will address machining issues through scientific analysis grounded in machining physics. Gear hobbing processes will be modeled off-line and in advance of process setup. This will allow new processes to achieve mature states faster, mature processes to be more productive, and improve part quality and reduce cost. In addition, engineers designing and manufacturing gears will be able to provide beneficial residual stress profiles to positively impact fatigue life and distortion. Tremendous opportunities exist for cost-reduction and performance improvement of transmission components by utilizing the proposed research in applications ranging from automotive and aircraft transmission systems, to energy production and heavy equipment manufacture. In addition to direct commercial and societal benefits, this project will: Further increase the science and engineering knowledge base in both industry and academia regarding the fundamental relationships between materials, processes, and product quality of transmission components; and Remove significant cost barriers that exist when investigating truly innovative manufacturing methods and implementation thereof.

Keywords:
Finite Element, Finite Element, machining, Physics-based Modeling, gear steels, Gear Hobbing

Phase II

Contract Number: N68335-12-C-0091
Start Date: 2/13/2012    Completed: 2/14/2014
Phase II year
2012
Phase II Amount
$1,499,943
This Small Business Innovation Research Phase II project, Gear Hobbing Predictive Model, will develop and demonstrate innovative physics-based modeling of gear machining processes the Navy needs to predict and improve residual stresses and related distortions, as well as reduce production cycle times and costs of transmission gears. Through targeted technology development, Third Wave Systems (TWS) will demonstrate a 35-50 percent reduction in gear machining time and cost without the need for additional capital equipment investment. This will be achieved through the advancement and application of both a detailed finite element modeling (FEM) of the tool-workpiece interaction, as well as a toolpath-level analysis. The combined outputs of these comprehensive models temperatures, residual stresses, forces, and power will provide the ability to predict and manage machining-induced residual stresses while simultaneously reducing machining cost and cycle time. The Phase II program will improve upon its Phase I advances in model development and validation by expanding the scope of these goals to a larger set of gear machining processes and components, and further demonstrating cycle time and cost improvements through close collaboration with gear manufacturers and DoD primes.

Benefit:
Current processes for producing transmission gears involve hobbing or shaping a forged stock to obtain the gear shape. The amount of residual stresses, distortions, and excess material generated during hobbing and following heat treatment processes dictate overall cycle times and component performance. Therefore, it is necessary to understand and control the sources of process cycle times, costs, residual stresses, and distortion to minimize production costs and improve transmission gear component performance. In contrast to the expensive, trial-and-error approaches currently used in practice, this Phase II program will seek to predict and control machining-induced effects on gear fabrication costs and performance through a scientific analysis grounded in machining physics. Tremendous opportunities exist for cost-reduction and performance improvement of transmission components by utilizing the proposed research in applications ranging from aircraft and automotive transmission systems, to energy production and heavy equipment manufacture. The primary thrust of this program is to develop and demonstrate sophisticated modeling capabilities, which will enable an end-to-end simulation of gear development and fabrication for lower costs and development times. As a result, gear designers will be able to predict, manage, and improve residual stresses to minimize distortion and improve fatigue life. Hob tool manufacturers will be able to design and produce more effective tooling that lasts longer and cuts better via force, stress, and temperature analyses during hobbing. Gear manufacturers will be able to analyze gear machining processes off-line, reducing cycle times, costs, and process setup times while eliminating trial-and-error approaches currently employed. Current practices for gear design and development rely heavily on empirical techniques and tribal knowledge; a modeling capability such as proposed in this program will allow gear manufacturing to be placed on a more scientific foundation, eliminating trial-and-error methods and ultimately producing higher quality gears in a faster and more cost-effective manner. Anticipated benefits of the Phase II program are: Availability of validated, detailed- and toolpath-level physics-based predictive models for gear machining that are general and extensible to a large variety of transmission components and materials Accelerated insertion of new gear materials by eliminating expensive, time-consuming trial-and-error process development Reduced part lead times and production costs of transmission gears via improved gear hobbing process enabled by physics-based modeling Prediction of workpiece residual stresses, cutting forces, temperatures, and tooling performance for gear machining processes Allow gear designers to manage and improve residual stresses, hob tool designers to improve tooling designs, and gear manufacturers to reduce cost and cycle time by 35 to 50 percent Advanced knowledge of material removal mechanisms in gear machining and their effects on subsequent heat treatments and grinding operations by placing the process on a scientific foundation through physics-based modeling Accurate and reliable tool-workpiece interaction model and toolpath-level models with associated optimization algorithms Improved fatigue life of gear components through residual stress management while reducing cycle times and cost. In addition to direct commercial and societal benefits, this project will: Further increase the science and engineering knowledge base in both industry and academia regarding the fundamental relationships between materials, processes, and product quality of transmission components; and Remove significant cost barriers that exist when investigating truly innovative manufacturing methods and implementation thereof.

Keywords:
gear steels, Gear Hobbing, turning, machining, Finite Element, Physics-based Modeling