Control systems for hydraulic axial displacement machines
AssigneeEaton Intelligent Power Limited
InventorsRichard Randel Lyman, Jr., Anil Balasaheb Kharpas, Avinash Dadaso Patil, Sanjay Dhondappa Mali, Matthew Edward Creswick
Life of this patent
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Abstract
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.
Claims24
A control system for a hydraulic axial displacement machine, comprising:
- a spool, a spool actuator, a pivotal feedback arm, a spring, and a feedback piston, the spool being coupled to the spring and adapted to move axially with the feedback piston between a charging position and a neutral position, the feedback arm being adapted to pivot proportionally to an angular position of a swashplate when the feedback arm is pivotally coupled to a servo-piston, the feedback arm being coupled to the feedback piston such that pivoting of the feedback arm activates the feedback piston and generates a spring compression force that compresses the spring between the spool and the feedback piston such that the spring is compressed by the spool and the feedback piston.
The control system of 9, wherein the cage defines a feedback piston cavity that at least partially receives the feedback piston and the spring;
- a spool cavity that at least partially receives the spool;
- and an actuator volume for receiving at least a portion of the solenoid or a pilot pressure line plug.
A control system for a hydraulic axial displacement machine, comprising:
- a feedback arm adapted to pivot proportionally to an angular position of a swashplate when the feedback arm is pivotally coupled to a servo-piston;
- a forward motion control module;
- and
- a reverse motion control module, each of the forward and reverse motion control modules comprising a spool movable between a charging position and a neutral position, a spool actuator, a spring, and a feedback piston, the spring being coupled to the spool and the feedback piston, the feedback piston being coupled to the feedback arm such that pivoting of the feedback arm in a first direction activates the feedback piston of the forward motion module and generates a spring compression force between the spool and the feedback piston of the forward motion control module, and such that pivoting of the feedback arm in a second direction activates the feedback piston of the reverse motion module and generates a spring compression force between the spool and the feedback piston of the reverse motion control module.
The control system of 16, wherein each of the cages defines a feedback piston cavity that at least partially receives the feedback piston and the spring;
- a spool cavity that at least partially receives the spool;
- and an actuator volume for receiving at least a portion of the spool actuator.
A control system for a hydraulic axial displacement machine, comprising:
- a forward motion module and a reverse motion module, each of the forward and reverse motion modules comprising a spool movable between a charging position and a neutral position, a spool actuator, a feedback piston, and a spring, the spring being received in the feedback piston and coupled to the spool such that axial movement of the spool in a first direction towards the charging position generates a compression force in the spring that biases the spool towards the neutral position, and such that axial movement of the feedback piston in a second direction that is opposite the first direction generates a compression force in the spring that biases the feedback piston towards the first direction.
A control system for a hydraulic axial displacement machine, comprising:
- a spool;
- a spool actuator;
- a pivotal feedback arm;
- a spring;
- a feedback piston, the feedback arm being coupled to the feedback piston, the spool being coupled to the spring and adapted to move axially with the feedback piston between a charging position and a neutral position, the feedback arm being adapted to be pivotally coupled to a servo-piston and further adapted to pivot proportionally to an angular position of a swashplate when the feedback arm is pivotally coupled to the servo-piston, the spring being adapted to bias the spool towards the neutral position of the spool;
- a controller;
- and
- an angle sensor adapted to detect an amount of pivoting of the feedback arm away from a position corresponding to a neutral position of the swashplate when the feedback arm is pivotally coupled to the servo-piston, such that a detected amount of pivot of the feedback arm is transmitted as a feedback signal to the controller, the controller being adapted to compare the detected pivot to a drive command signal,
- wherein the controller is adapted to transmit an error signal to the spool actuator in response to a discrepancy between the drive command signal and the feedback signal, the error signal causing the spool to move axially to compensate for the discrepancy.
Dependencies are inferred from the claim text.