Slipping Rotating Band with Composite Inner Ring for Projectile Launch
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Solution Overview
Problem
Existing slipping rotating bands on projectiles detach after launch, posing a risk of injury and damage due to becoming projectiles themselves, and are unsuitable for roll-stable, non-rotating projectiles that require low angular acceleration forces.
Innovation Solution
A slipping rotating band comprising an inner concentric ring made of fibre-reinforced or particle-reinforced polymer composite and an outer concentric ring with a polyurethane elastomer, designed to remain attached throughout the launch and flight, with a wedge-shaped or sawtooth contact surface for enhanced adhesion and gas sealing, and a chamfered outer ring for effective deformation against the barrel rifling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional slipping rotating band is used, then the projectile can be launched from a rifled barrel with low rotation, but the rotating band detaches after launch posing safety risks
Solution Approach 1:
The rotating band is constructed as a composite structure with an inner ring made of fibre-reinforced or particle-reinforced polymer composite material and an outer ring made of polyurethane elastomer. The composite materials provide enhanced mechanical properties including strength, stiffness, and attachment reliability, preventing detachment while maintaining the slipping function for low rotation.
2Strength
If a fixed rotating band is used to achieve good friction coupling, then the projectile rotates significantly, but this is undesirable for roll-stable guidable projectiles
Solution Approach 1:
The rotating band is designed to be slippably fitted on the projectile, allowing relative motion between the band and projectile during launch. The inner ring slips on the projectile surface while the outer ring seals against the barrel, creating a dynamic system that provides gas seal and limited friction coupling without fully rotating the projectile, thus maintaining roll stability.
3Reliability
If the rotating band is made of soft material for gas sealing, then gas seal is improved, but the band may deform excessively and detach
Solution Approach 1:
The outer ring is made of polyurethane elastomer which provides excellent gas sealing properties through elastic deformation against the barrel rifling. The inner ring is made of fibre-reinforced or particle-reinforced polymer composite material that provides structural strength and rigidity. The combination allows the outer ring to seal effectively while the inner ring prevents excessive deformation and detachment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution ensures the rotating band remains securely attached to the projectile, reducing the risk of injury and damage, while providing a low-friction, gas-tight seal and controlled rotation, essential for roll-stability and reduced angular acceleration forces.
Implementation Method 1
the rotating band is partially deformed by the rifling and thus the rotating band grips the rifling
Implementation Method 2
The coupling between the rotating band and the projectile is constructed such that the friction is low and slipping or sliding against the projectile occurs
Data Source
Figure 1
Figure 2~4
AI summary
The invention relates to a projectile (6) provided with a slipping rotating band (1) which is designed for firing from a weapon system with a rifled barrel. The rotating band (1) comprises an inner ring (2) and an outer ring (3) that seals against the barrel. The outer ring is fitted on the outer surface of the inner ring and the inner ring is slippably fitted on the projectile. The rotating band (1) is configured to remain fitted on the projectile (6) from launcher to target by virtue of the fact that the inner ring (2) is made of fibre-reinforced polymer composite or particle-reinforced polymer composite, or fibre-reinforced metal matrix composite or particle-reinforced metal matrix composite. The invention also relates to a slipping rotating band (1) and to a method for producing a slipping rotating band (1) in which the outer ring (3) is affixed to the inner ring (2).