Hydraulic Axial Machine Feedback Assembly for Low-Hysteresis Control
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Solution Overview
Problem
Existing hydraulic axial displacement machines lack effective control and feedback systems, leading to inefficiencies in volumetric displacement regulation and increased hysteresis due to direct mechanical contact and lack of modular design.
Innovation Solution
A feedback assembly with a spool, spool actuator, pivotal feedback arm, and feedback piston, utilizing compound springs and separate modules for forward and reverse motion, provides proportional feedback information and reduces friction through spring-loaded mechanisms, enabling improved control and compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a feedback system is implemented to regulate volumetric displacement, then control precision is improved, but device complexity increases
Solution Approach 1:
The patent implements a feedback system where a feedback piston is coupled to the swashplate through a feedback arm. The feedback piston moves in response to swashplate position changes and provides feedback pressure to a spool valve, creating a closed-loop control system that automatically regulates volumetric displacement without requiring complex external control mechanisms
Solution Approach 2:
The feedback piston acts as an intermediary element between the swashplate and the spool valve. It converts swashplate position changes into pressure signals that automatically control the spool valve position, eliminating the need for complex electronic sensors and control circuits while maintaining precise control
2Device complexity
If direct mechanical contact is used in the feedback mechanism, then device complexity is reduced, but hysteresis increases
Solution Approach 1:
The patent replaces direct mechanical contact with hydraulic coupling through the feedback piston. The feedback piston is acted upon by hydraulic pressure from the servo-piston and transmits this pressure to the spool valve through fluid coupling, eliminating mechanical friction and hysteresis while maintaining system simplicity
3Device complexity
If a single control module is used for both forward and reverse motion, then device complexity is reduced, but adaptability decreases
Solution Approach 1:
The patent divides the control system into separate forward motion and reverse motion modules. Each module has its own spool valve, feedback piston, and associated control lines, allowing independent optimization and control of forward and reverse operations while maintaining overall system coherence
4Ease of repair
If modular design is implemented for forward and reverse motion modules, then ease of repair is improved, but device complexity increases
Solution Approach 1:
The control system is segmented into modular forward and reverse motion units, each containing complete control functionality. These modules can be independently removed, repaired, or replaced without affecting the other module, significantly easing maintenance while the modular architecture itself provides clarity that offsets the perceived complexity
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 enhances control precision, reduces hysteresis, and allows for modular assembly and maintenance, providing improved reliability and redundancy in hydraulic axial displacement machines.
Implementation Method 1
a feedback spring, the feedback spring being adapted to bias the spool towards the neutral position of the spool
Implementation Method 2
the spool actuator includes a solenoid adapted to receive electrical drive command signals
Data Source
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AI summary
Control systems and feedback assemblies for hydraulic axial displacement machines, such as pumps and motors. The control systems and feedback assemblies can reduce friction on the charging spools and provide for a more reliable return of the swashplate to a neutral position. Aspects of the control systems and feedback assemblies can be modularized for, e.g., easy maintenance and to reduce the overall size of the system.