Static-Sealed Hydraulic Actuator for Friction-Free Zero Leakage
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Solution Overview
Problem
Traditional hydraulic actuators face issues with friction, leakage, hysteresis, and nonlinear characteristics, which hinder high-precision displacement and force control, especially in high-frequency and high-stiffness applications, and require significant axial space.
Innovation Solution
A hydraulic actuator design featuring a thickened disc structure with a control cavity and a drive oil access hole, utilizing a static seal and alternating stiffness enhancement and weakening areas to minimize friction and leakage, and an electro-hydraulic servo control system for precise displacement and force control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If seal ring hydraulic actuator is used to separate high and low-pressure oil chambers, then the actuator can maintain pressure difference, but friction and leakage are introduced between the high and low-pressure chambers
Solution Approach 1:
The invention extracts and removes the seal ring component from the hydraulic actuator structure. By eliminating the seal ring, the patent achieves zero leakage and no friction between high and low-pressure oil chambers, while maintaining pressure difference through the alternative piston structure with oil access holes
Solution Approach 2:
The invention replaces the traditional mechanical seal ring system with a piston structure featuring oil access holes. This substitution eliminates the need for sliding contact and sealing surfaces, thereby removing friction and leakage while maintaining the essential function of pressure difference maintenance
2Speed
If clearance seal hydraulic actuator is used to reduce friction by improving machining accuracy, then frequency response is improved, but leakage increases significantly at high pressure
Solution Approach 1:
The invention removes the clearance seal structure entirely and replaces it with a piston design featuring oil access holes. This extraction eliminates the trade-off between friction reduction and leakage, achieving both zero friction and zero leakage simultaneously while maintaining high frequency response
3Device complexity
If artificial muscle hydraulic actuator is used to achieve axial displacement through radial deformation, then structure is simplified, but axial size must be increased significantly
Solution Approach 1:
The invention transitions from radial deformation mechanism to axial deformation mechanism by introducing a piston structure with oil access holes. This dimensional change allows the actuator to achieve axial displacement through direct axial movement of the piston, dramatically reducing the required axial size while maintaining structural simplicity
4Length of moving object
If artificial muscle hydraulic actuator is used with large axial size to achieve larger axial displacement, then stroke is increased, but lateral stiffness is reduced and hysteresis increases
Solution Approach 1:
The invention changes the deformation mechanism from radial to axial by using a piston structure. This allows large axial displacement to be achieved through piston stroke rather than radial expansion, thereby maintaining high lateral stiffness and reducing hysteresis while achieving the required axial displacement
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 enables high-frequency and high-precision displacement and force control with reduced axial size, low manufacturing costs, and no motion pair, effectively avoiding friction, leakage, and nonlinear characteristics, enhancing stiffness and precision.
Implementation Method 1
outputs an axial displacement based on the elastic deformation of the material
Implementation Method 2
The hydraulic actuator is an important component of the fluid transmission and control system, which is responsible for the important task of converting hydraulic energy into mechanical energy
Data Source
AI summary
A hydraulic actuator with no friction and zero leakage and its drive system are provided. The hydraulic actuator includes a thickened disc structure A and a thickened disc structure B. The second end face of the thickened disc structure A is connected with the first end face of the thickened disc structure B, and a control cavity is formed between the second end face of the thickened disc structure A and the first end face of the thickened disc structure B. The drive oil access hole is arranged on the thickened disc structure B, and the control cavity is connected with the drive oil access hole. The displacement output method based on elastic deformation is adopted, which completely avoids the nonlinear phenomena such as leakage and friction, and reduces the difficulty of high-precision control of the actuator.