Rotary Actuator Load Control Using a Parallelogram Linkage
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Solution Overview
Problem
Existing rotary actuators in aerial platforms require separate integration of load-sensing sensors, which are prone to inaccurate readings due to bending moments and require custom design efforts, complicating manufacturing and certification processes.
Innovation Solution
An integrated rotary actuator unit with a load cell and articulated parallelogram link mechanism that transfers load forces directly along the detection axis, minimizing bending moments and incorporating a positioning sensor for continuous angular control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate load-sensing sensors are integrated into existing rotary actuators, then load detection capability is added, but measurement precision deteriorates due to bending moments affecting the sensor readings
Solution Approach 1:
The patent introduces an articulated parallelogram link mechanism as an intermediary between the actuator and the load cell. This mechanism includes four links connected by hinges that form a parallelogram structure, which transfers the load force from the platform to the load cell along a single axis without introducing bending moments. The parallelogram mechanism ensures that the load cell only experiences axial compression or tension, eliminating the measurement errors caused by bending moments while maintaining reliable load detection capability.
2Adaptability or versatility
If separate load-sensing sensors and rotary actuators are integrated, then functional capability is improved, but device complexity increases due to custom design and integration requirements
Solution Approach 1:
The patent merges the rotary actuator and the load sensing system into a single integrated unit. The load cell is mounted directly on the actuator's support structure, and the articulated parallelogram link mechanism is incorporated into the actuator assembly. This integration eliminates the need for separate mounting brackets and complex assembly procedures, reducing device complexity while maintaining enhanced functional capability for both rotation and load detection.
Solution Approach 2:
The integrated rotary actuator unit performs multiple functions: it provides rotational movement for the aerial platform and simultaneously detects the load on the platform through the incorporated load cell. The articulated parallelogram mechanism serves dual purposes by both transferring the load force accurately and maintaining the structural integrity of the actuator assembly. This multi-functionality reduces the need for separate components and simplifies the overall system.
3Ease of manufacture
If load cells are directly mounted on actuator brackets, then integration is simplified, but manufacturing precision requirements increase to prevent incorrect readings from bending moments
Solution Approach 1:
The articulated parallelogram link mechanism acts as an intermediary that decouples the mounting precision requirements from the load cell. Instead of requiring precise mounting of the load cell directly on the actuator brackets, the parallelogram mechanism transfers the load through a series of hinged links that naturally guide the force along the correct axis. This reduces manufacturing precision requirements while maintaining ease of manufacture, as the mechanism can be assembled with standard tolerances.
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
Provides reliable load detection and angular positioning, ensuring stable platform operation, reducing maintenance, and offering a 'plug-and-play' solution for aerial platform manufacturers.
Implementation Method 1
a load cell (300) comprising a base body (301), a wiring harness (302) and an upper load button (303), the load cell being arranged in the upper end bracket (202)
Implementation Method 2
articulated parallelogram link mechanism that transfers load forces directly along the detection axis
Implementation Method 3
incorporating a positioning sensor for continuous angular control
Data Source
AI summary
Disclosed is a rotary actuator unit with a casing and an internal rotating shaft integral with rotating end flanges projecting from said casing at a main axis of rotation, a load cell apt to detect a load acting on one of said rotating end flanges, further comprising an articulated link parallelogram frame defined by a pair of end brackets constrained to said rotating end flanges, equipped with respective hinge bodies defining parallel hinge axes in which first hinge pins are pivotingly engaged, a pair of lower and upper end plates hinged at proximal end to said hinge pins, said lower and upper end plates being provided with second hinge pins at a distal end, and an attachment plate hinged at respective ends to said second hinge pins, and in which said upper end plates is abutting said load cell and attachment plate has fastening means to engage a user structure.