Hydraulic Rotary Drive Feedback Control for Precise Gear Engagement
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Solution Overview
Problem
Existing large manipulators with hydraulic rotary drives face challenges in precisely controlling the engagement of spur gears, leading to uneven rotational movement and potential damage to tooth tips, due to imprecise switching phase control.
Innovation Solution
Incorporating a sensor arrangement connected to a control unit that detects the positions of annular pistons along their sliding path, allowing for precise control of hydraulic fluid application and speed regulation, thereby ensuring uniform rotary movement and reducing load on tooth tips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a mechanical control system using a control disk is used to control the switching impulses for hydraulic valves, then the device complexity is reduced, but the measurement precision of piston position and switching phase control deteriorates
Solution Approach 1:
The patent replaces the mechanical control disk system with an electronic control system that uses sensors (magnetic, capacitive, or inductive) to detect piston position and a control unit (PLC or microcontroller) to generate switching impulses. This substitution eliminates the mechanical complexity of the control disk while achieving superior measurement precision through electronic sensing and digital processing.
Solution Approach 2:
The patent implements a feedback mechanism where sensors continuously monitor the actual position of the annular pistons and feed this information back to the control unit. The control unit compares the detected position with the desired position and adjusts the switching impulses accordingly, ensuring precise control of the engagement position of the spur gears while maintaining manageable system complexity through automated closed-loop control.
2Ease of operation
If the switching phase control is imprecise, then the ease of operation is improved, but the reliability of tooth engagement and uniformity of rotational movement deteriorates
Solution Approach 1:
The control unit uses feedback from position sensors to automatically adjust the switching phase of hydraulic valves, ensuring precise control of piston movement and gear engagement. This eliminates the need for manual adjustment while guaranteeing reliable tooth engagement and uniform rotational movement under varying load conditions.
Solution Approach 2:
The patent employs dynamic control where the switching impulses are continuously adjusted based on real-time piston position feedback. This dynamic adjustment ensures that the engagement position of spur gears is precisely controlled regardless of load variations, maintaining high reliability while keeping the operation simple through automated adaptation.
3Productivity
If the annular pistons move at uncontrolled speeds, then the productivity of the rotary drive is improved, but the manufacturing precision of tooth engagement and uniformity of rotary motion deteriorates
Solution Approach 1:
The control unit dynamically regulates the speed of annular pistons based on real-time position feedback. During engagement phases, the control unit reduces piston speed to ensure precise tooth engagement, while during non-engagement phases, it allows higher speeds to maintain productivity. This dynamic speed control achieves both high precision and high productivity.
Solution Approach 2:
The patent employs periodic control where the piston speed is cyclically adjusted according to the engagement cycle. Before each gear engagement, the control unit slows down the pistons to ensure precise positioning, then accelerates them during the power transmission phase. This periodic speed variation ensures precise tooth engagement while maintaining overall high productivity of the rotary drive.
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 precise regulation of the switching phase and speed of annular pistons, ensuring uniform rotary movement, reducing wear, and extending the service life of the manipulator while preventing damage to the spur gears.
Implementation Method 1
the sensor arrangement (10) is connected to the control unit (14) for detecting the positions of the annular pistons (5, 6) along the respective sliding path (a)
Implementation Method 2
the sensor arrangement (10) is connected to the control unit (14) for detecting the positions of the annular pistons (5, 6) along the respective sliding path (a)
Implementation Method 3
at least two annular pistons (5, 6) fixedly connected to the first rotary drive element (2) and axially movable on the first rotary drive element between two end positions along a sliding path (a) by means of a hydraulic fluid
Implementation Method 4
the face teeth of the annular pistons can be engaged and disengaged from the corresponding annular teeth of the second rotary drive element by moving the annular pistons on the first rotary drive element, thereby generating a rotary movement of the second rotary drive element relative to the first rotary drive element
Data Source
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AI summary
The invention relates to a hydraulic rotary drive (1) with a first rotary drive element (2), at least two annular pistons (5, 6) which are connected to the first rotary drive element (2) for rotation therewith and are movable axially on the first rotary drive element (2) along a sliding path (a) between in each case two end positions (3, 3a, 4, 4a) by being acted upon with a hydraulic fluid, wherein each annular piston (5, 6) has two annular spur toothings (7, 7a) which are directed away from each other, a second rotary drive element (8) with annular toothings (9, 9a, 9b, 9c) which are complementary to the spur toothings (7, 7a) of the annular pistons (5, 6), wherein the spur toothings (7, 7a) of the annular pistons (5, 6) can be brought into engagement and out of engagement with the associated annular toothings (9, 9a, 9b, 9c) of the second rotary drive element (8) by movement of the annular pistons (5, 6) on the first rotary drive element (2), as a result of which a rotational movement of the second rotary drive element (8) relative to the first rotary drive element (2) arises, and a control unit (14) which controls the action upon the annular pistons (5, 6) with the hydraulic fluid, wherein the control unit (14) is configured to bring about a reciprocating movement of the annular pistons (5, 6) on the shaft (2) in accordance with an operating signal. The invention proposes providing a sensor arrangement (10, 11, 12, 17), which is connected to the control unit (14), for sensing the positions of the annular pistons (5, 6) along the respective sliding path (a). The invention further relates to a large manipulator (100) having a rotary drive (1) of this kind and to a truck-mounted concrete pump (200) having a large manipulator (100) of this kind.