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In Vehicle Adjustable Torsion Bar Technologies



OBJECTIVE: Develop a novel new combat vehicle torsion bar system that can vary vehicle pitch, attitude, provide ride height management and wheel lockout capability for ground combat vehicles. This will allow combat vehicles to improve and/or regain lost mobility, provide additional tractive effort, increase ride quality and augment towing and recovery. 

DESCRIPTION: Current U.S. tracked combat vehicles use a torsion bar based suspension system. These systems are proven and provide the needed vehicle spring force at a reasonable cost to the platform. However, torsion bar technology offers very little adjustment to compensate for increased vehicle weights and does not offer newer features such as height management found on more complex suspension systems such as External Suspension Units (ESU’s). There have been limited advances in torsion bar technology over the years. This SBIR will develop new possibilities to increase the capabilities of torsion bars such as (but not limited to) adjustable anchors and dual rate torsion bars, for use in combat vehicle applications. The ability of these new torsion bar technologies would increase off-road mobility over a larger range in platform weights. For example, adjustable torsion bar anchor points can control vehicle ride height and pitch to increase transportability options or adjust for terrain conditions during operational maneuvers. Likewise, either this adjustable anchor or dual rate torsion bar could also provide a partial or full wheel lockout. Such technologies have previously existed only on ESU suspensions which offer these capabilities at increased cost and complexity. This SBIR will evaluate if novel, new torsion bar systems can be designed for ground combat vehicles which encapsulate the advantages of ESU’s characteristics, wheel lockout capability, as well as increased capability for ride height control. These new technologies would be specific only to the torsion bar system and would be independent of struts and damper modifications (i.e. out of scope) or damper type (traditional shock or rotary dampers). The addition of these features could be applied to the existing hull structures without major modifications as usually required by ESU technology. 

PHASE I: Develop a preliminary design of an on the move in vehicle adjustable torsion bar. The range of adjustment should be enough to allow ride height adjustment utilizing the full range of suspension travel. The feasibility, methodology, package size, power requirement, and amount of adjustability would be developed under this first phase. When Phase I is complete, a low risk preliminary design using packaging constraints, vehicle characteristics/weight from a current heavy combat platform (i.e. Abrams, or M88) will be complete. A cost and performance benefit report with comparisons to the stock vehicle suspension and an ESU style suspension will also be completed, along with an assessment of the capability increase this system potentially offers. 

PHASE II: Refine, fabricate and integrate the Phase I design onto a heavy combat platform. Perform a test and evaluation to determine the performance benefits these systems offer over the current torsion bar system. 

PHASE III: Make any required modifications that was discovered in phase II and prepare for commercialization. This design will be vehicle specific and have a design and integration approach that has been approved by the specific vehicle PM. 



2:  Value stream 1 of the 30 year strategy (references ESU's but are usually to expensive)




KEYWORDS: Keywords: Torsion Bar, Anchor, Ride Height Control, Improved Towing, Lift And Carry, M88, Abrams, Bradley 

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