Rotary Vane Actuator Seal Compression Lock
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rotary hydraulic actuators face challenges in achieving leak-free performance and maintaining positional accuracy due to internal leakage characteristics, which is critical in applications like aircraft primary flight controls where continuous inertial loading is required without external fluid power supply.
Innovation Solution
A sealing mechanism for rotary vane actuators that includes a compressible seal, a compression member, and a locking piston, which, when actuated by pressurized fluid, compresses to reduce internal leakage and maintain position by locking the fluid within the pressure chamber, providing a fail-safe mechanism in case of fluid pressure loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a typical rotary hydraulic actuator design is used, then the actuator can provide continuous inertial loading, but internal leakage occurs which degrades positional accuracy
Solution Approach 1:
The patent applies preliminary action by pre-compressing the seal against the rotor vane end surfaces using a compression member before fluid pressure is applied. This initial compression creates a tighter seal that prevents internal leakage from occurring in the first place, rather than attempting to correct leakage after it occurs. The compression member is biased by a spring to maintain constant contact pressure on the seal, ensuring leak-free operation throughout the actuator's operational range.
Solution Approach 2:
The patent changes the physical parameter of seal compression force by introducing a mechanically actuated lock that can transition between locked and unlocked states. When locked, the mechanism applies additional compressive force to the seal, dramatically reducing internal leakage. This parameter change allows the system to switch between normal operation mode and leak-prevention mode, maintaining positional accuracy when needed.
2Reliability
If the actuator uses blocked fluid column to hold position, then it can maintain position without external fluid power supply, but leakage prevents accurate position holding
Solution Approach 1:
The patent applies preliminary action by pre-compressing the seal against the rotor vane end surfaces using a compression member before fluid pressure is applied. This initial compression creates a tighter seal that prevents internal leakage from occurring in the first place, rather than attempting to correct leakage after it occurs. The compression member is biased by a spring to maintain constant contact pressure on the seal, ensuring leak-free operation throughout the actuator's operational range.
Solution Approach 2:
The patent changes the physical parameter of seal compression force by introducing a mechanically actuated lock that can transition between locked and unlocked states. When locked, the mechanism applies additional compressive force to the seal, dramatically reducing internal leakage. This parameter change allows the system to switch between normal operation mode and leak-prevention mode, maintaining positional accuracy when needed.
3Duration of action of moving object
If the actuator is designed for continuous operation, then it can provide sustained inertial loading, but leakage accumulates over time degrading performance
Solution Approach 1:
The patent applies self-service by designing a system where the mechanically actuated lock automatically engages and disengages based on operational conditions. The lock can be activated by a solenoid or other actuating mechanism to apply additional seal compression when leakage is detected or during position-holding phases, without requiring external intervention or maintenance. This self-regulating capability ensures consistent performance over extended operational durations.
Solution Approach 2:
The patent changes the physical parameter of seal compression force by introducing a mechanically actuated lock that can transition between locked and unlocked states. When locked, the mechanism applies additional compressive force to the seal, dramatically reducing internal leakage. This parameter change allows the system to switch between normal operation mode and leak-prevention mode, maintaining positional accuracy when needed.
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 significantly reduces internal leakage and enhances position-holding capability, ensuring reliable operation even in failure modes by containing fluid pressure and maintaining rotational position during malfunctions.
Implementation Method 1
a compressible seal slidably mounted on a central longitudinal shaft of a rotor assembly
Implementation Method 2
the vanes of the rotor are moved by fluid under pressure
Implementation Method 3
a locking piston slidably mounted on the central longitudinal shaft, the locking piston including an opening sized to receive the central longitudinal shaft, an end surface adapted to contact the compression member, a circumferential surface sized to be received in the bore of the housing, and a lateral surface adapted to receive actuation fluid
Data Source
AI summary
The subject matter of this specification can be embodied in, among other things, a seal assembly that includes a compressible seal slidably mounted on a central longitudinal shaft of a rotor assembly, the seal having a first lateral surface adapted for contacting a first end surface of a first stator and a first end surface of the second stator and a first end surface of a first longitudinal vane and a first end surface of a second longitudinal vane, a compression member slidably mounted on the shaft, and a locking piston slidably mounted on the shaft, the locking piston including an opening sized to receive the shaft, an end surface adapted to contact the compression member, a circumferential surface sized to be received in the bore of the housing, and a lateral surface adapted to receive actuation fluid.