Integrated Servo Unit Layout for Axial Piston Displacement Control
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Solution Overview
Problem
Existing hydraulic systems face challenges in compactly adjusting displacement volumes of rotating groups within hydrostatic axial piston units and transmissions, as conventional servo units occupy valuable space and require larger housings, necessitating a more efficient and space-conscious displacement control system that allows for manual, hydraulic, and electronic control with high variability and mechanical or electrical feedback.
Innovation Solution
A variable displacement hydraulic axial piston unit with a swivel element that can be tilted around a perpendicular axis, actuated by a servo unit housed within the unit, where the servo unit is positioned on the opposite side of the swivel element from the cylinder block, allowing for compact design and adjustable displacement control through a servo piston and cylinder system, with optional servo springs for restoring the initial position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional servo unit is used to adjust the displacement volume, then the displacement control function is achieved, but the construction space is increased
Solution Approach 1:
The servo unit is nested within the housing of the axial piston unit, with the servo cylinder and servo piston integrated into the existing structure. The servo unit utilizes the available space within the housing rather than adding external components, thereby achieving displacement control without increasing the overall construction space.
Solution Approach 2:
The housing serves multiple functions: it contains the axial piston unit components and simultaneously accommodates the servo unit for displacement control. This multi-functional design eliminates the need for separate external servo housing, reducing the total volume required.
2Volume of moving object
If the servo unit is positioned on the opposite side of the swivel element from the cylinder block, then the space usage is optimized, but the mechanical arrangement becomes more complex
Solution Approach 1:
The servo unit is arranged in a different spatial dimension relative to the cylinder block, positioned on the opposite side of the swivel element. This dimensional reconfiguration optimizes space usage by utilizing previously unused areas within the housing, while the complexity is managed through careful design of the force transmission path.
Solution Approach 2:
The swivel element acts as an intermediary component that transmits the force from the servo piston (positioned on the opposite side) to the cylinder block. This intermediary arrangement allows the servo unit to be positioned optimally for space efficiency while maintaining effective mechanical coupling between the actuator and the displacement control mechanism.
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
This configuration enables efficient adjustment of displacement volumes without increasing the apparatus' size, allowing for high variability and load-dependent or independent control, while maintaining mechanical or electrical position feedback, thus optimizing space usage and operational flexibility.
Implementation Method 1
A servo piston (14) arranged within the servo cylinder (12) can be pressurized at its servo piston head (15) within the servo cylinder (12) so that a movement of the servo piston (14)
Data Source
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AI summary
Variable displacement hydraulic unit (1) with a housing (3) in which at least one rotating group (5) is housed, wherein the displacement volume of the rotating group (5) is variably adjustable by means of a swivel element (7) able to tilt around a tilt axis (8) perpendicular to the rotational axis (6) of the rotating group (5). The swivel element (7) can be actuated by at least one servo unit (10) comprising a servo cylinder (12) integrated in the housing (3) and a servo piston (14) moveably within the servo cylinder (12). The head (15) of the servo piston (14) can be pressurized in the servo cylinder (12) such that a movement of the servo piston (14) coupled to the swivel element (7) via a servo piston shaft (16) tilts the swivel element (7); wherein the servo unit (10) is located within the housing (3) at that side of the swivel element (7) facing away from the rotating group (5) are supported and follow a working direction substantially parallel to the rotational axis (6) of the rotating group (5).