Projectile Recovery Parachute Bearing for High-Spin Decoupling
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Solution Overview
Problem
Existing projectile recovery systems, such as the Soft-Recovery Parachute Module (SRPM), fail to effectively decouple the parachute lines from the payload in high-performance, long-range artillery launches, leading to parachute collapse or line separation and subsequent payload damage due to increased spin rates and firing pressures.
Innovation Solution
A ballistic projectile recovery system with a forward-facing opening deploying a parachute through a rotational bearing assembly, using taper bearings and a deformable spacer to decouple riser lines from the projectile, and a bidirectional drag element to stabilize the payload during descent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the projectile is fired from high-performance, long-range artillery with increased barrel length and caliber, then the range and penetrating power are improved, but the spin rate and firing pressure increase causing rotary bearing failure
Solution Approach 1:
A fluid dynamic bearing is introduced as an intermediary between the parachute assembly and the spinning projectile body. This bearing uses fluid dynamics to decouple the rotational motion of the projectile from the parachute suspension lines, allowing the parachute to remain stationary while the projectile spins around it. The fluid bearing eliminates direct mechanical contact that would otherwise cause failure under high spin rates and pressures.
Solution Approach 2:
The traditional rotary mechanical bearing is replaced with a fluid dynamic bearing system. Instead of relying on mechanical rolling elements that fail under high-speed rotation and pressure, the invention uses fluid dynamics to provide the necessary support and decoupling function, substituting a mechanical system with a fluid-based system that can withstand the extreme conditions.
2Device complexity
If the parachute lines are directly attached to the payload, then the structure is simple, but the continued spinning twists and collapses the parachute canopy
Solution Approach 1:
The fluid dynamic bearing acts as an intermediary between the parachute suspension lines and the spinning payload. It allows the parachute canopy to maintain a stable, non-rotating position while the payload continues to spin, preventing the twisting and collapse that would occur with direct attachment.
Solution Approach 2:
The system is segmented into two independent rotational systems: the spinning payload and the stationary parachute. The fluid dynamic bearing creates a clear separation between these two segments, allowing independent motion without interference. This segmentation prevents the coupling of rotational motions that would otherwise cause canopy collapse.
3Length of moving object
If the barrel length is extended to increase caliber and range, then the firing pressure and spin rate increase, but the existing SRPM system fails to decouple the lines from the payload
Solution Approach 1:
The existing mechanical decoupling system is replaced with a fluid dynamic bearing system that can handle the increased spin rates and pressures generated by longer, larger-caliber barrels. The fluid bearing provides reliable decoupling without the mechanical failures that plague the traditional SRPM system under these extreme conditions.
Solution Approach 2:
The invention changes the fundamental operating parameters of the bearing system by transitioning from solid mechanical contact to fluid dynamic interaction. This parameter change allows the system to operate successfully at the higher spin rates and pressures generated by extended barrel lengths and increased caliber.
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 system ensures intact recovery of the payload by reducing bearing failure and maintaining parachute integrity, even at high spin rates, through reduced friction and heat buildup in the bearings, thereby enhancing the reliability of post-firing examination.
Implementation Method 1
a fluid dynamic bearing to decouple the parachute assembly from rotation with respect to the spinning projectile
Implementation Method 2
A parachute is deployable through the forward-facing opening and is connected to the projectile by one or more riser lines
Data Source
AI summary
A ballistic projectile recovery system includes a forward opening in an ogive of the projectile, selectively opened to deploy a portion of the recovery system. A parachute is deployable through the opening, connected to the projectile by riser line(s). A rotational bearing assembly makes the riser line(s) rotationally decoupled from the projectile. A bidirectional drag inducing element extends externally of an ogive of the projectile. A spacer, between a setback plate and the rotational bearing assembly, is deformable in at least the longitudinal direction of the projectile. The setback plate is movable between a first position to a second position made available by the compression of the spacer. In the second position, the setback plate is in contact with the projectile, providing a load path that avoids the rotational bearing assembly to take up strain applied to the projectile in at least the longitudinal direction.