Hydraulic Piston Sleeve Counterforce Design for High-Speed Sealing
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Solution Overview
Problem
Existing hydraulic devices experience leakage due to tilting torques on sleeves at high rotational speeds, leading to inefficiency, as passive spring means are insufficient to prevent tilting and maintain sealing at high rotational speeds.
Innovation Solution
Incorporation of actuators, such as levers with counterweights, that exert counter forces on sleeves to balance centrifugal forces, minimizing tilting torques and maintaining sealing by actively counteracting the tilting movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If passive spring means are used to press sleeves against barrel plates, then sealing is maintained at low rotational speeds, but at high rotational speeds the spring force is insufficient to prevent tilting of sleeves
Solution Approach 1:
The patent employs actuators that generate counter forces opposing the centrifugal forces acting on sleeves during rotation. These actuators actively balance the tilting torques that increase with rotational speed, maintaining sleeve alignment and sealing effectiveness across the full operational speed range, whereas passive springs cannot compensate for high-speed centrifugal effects.
Solution Approach 2:
The patent transitions from static passive spring means to dynamic active actuators that can adjust their output forces in response to varying operational conditions. The actuators are controlled to increase counter forces with increasing rotational speed, adapting to the changing centrifugal loads that cause sleeve tilting at high speeds.
2Reliability
If sleeves are pressed against barrel plates through compression chamber pressure, then sealing is improved, but at low oil pressure the pressing force is very low leading to tilting and leakage
Solution Approach 1:
The actuators provide active counter forces that compensate for insufficient compression chamber pressure at low oil pressures. By generating opposing forces to centrifugal tilting torques, the actuators maintain sleeve alignment and prevent leakage even when the passive pressure-based pressing mechanism is inadequate.
3Reliability
If spring force is increased to prevent tilting at high rotational speeds, then sealing is improved, but the device complexity and energy consumption increase
Solution Approach 1:
The patent employs controllable actuators that can dynamically adjust their output forces based on operational conditions rather than using oversized springs that must accommodate maximum speed conditions throughout. This dynamic approach allows for optimized force application that reduces overall system complexity compared to heavily reinforced passive spring mechanisms.
Solution Approach 2:
The actuators are controlled to vary their counter forces with rotational speed, applying appropriate force levels matched to actual operating conditions. This parameter-based control enables effective sealing at high speeds without requiring the constant high forces that would necessitate complex oversized spring mechanisms.
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 actuators effectively minimize tilting torques and prevent leakage by balancing centrifugal forces, ensuring efficient operation even at high rotational speeds.
Implementation Method 1
a centrifugal force on the cooperating sleeve acts in radial direction from the second axis of rotation between the barrel plate and a center point of the piston head causing a tilting torque about the center point of the piston head
Implementation Method 2
Incorporation of actuators, such as levers with counterweights, that exert counter forces on sleeves to balance centrifugal forces
Data Source
AI summary
A hydraulic device comprises a housing and a shaft with a flange extending perpendicularly to a first axis of rotation. A plurality of pistons are fixed to the flange and move each in a sleeve supported by and rotatable with a barrel plate. The barrel plate is provided with a plurality of actuators for exerting counter forces (Fa) on the respective sleeves in a direction and at a location such that at least when one of the pistons is at bottom dead center under operating conditions the counter force on the cooperating sleeve acts along a line at a distance from the center point of the piston head and causes a counter torque about the center point of the piston head against the tilting torque, wherein the actuators are controlled such that the counter forces increase with increasing rotational speed of the barrel plate about the second axis of rotation.