Hexapod Electric Actuator Damping for Breakdown Shock Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric rams in hexapod positioners for flight simulators lack effective solutions for dissipating significant energy during extreme breakdowns, leading to unsafe acceleration and force peaks, as conventional hydraulic and elastomer-based damping solutions are inefficient or bulky and cannot be adapted to the load.
Innovation Solution
A modular system combining electric actuators with hydraulic dampers positioned on the actuator's fixed structure, allowing independent calibration and placement of hydraulic dampers to absorb and dissipate energy, thereby protecting the motor and structure from shock forces and accelerations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If hydraulic rams are used to move loads in excess of fourteen tons, then significant energy levels can be absorbed and dissipated during extreme breakdowns, but hydraulic systems consume more electricity and are less environmentally friendly
Solution Approach 1:
The system is divided into two independent parts: electric actuators for normal operation and hydraulic dampers for shock absorption. This segmentation allows each component to perform its specialized function optimally - electric actuators provide precise control with low energy consumption during normal operation, while hydraulic dampers handle energy dissipation during extreme breakdowns without requiring continuous power
Solution Approach 2:
Hydraulic dampers are introduced as intermediary elements between the electric actuators and the load. These dampers act as a buffer that absorbs and dissipates kinetic energy during extreme breakdowns, protecting the electric actuators from shock forces while maintaining the energy efficiency benefits of electric drive systems
2Reliability
If dampers are positioned on electric rams with ball screw, then shock damping is provided, but the dampers are inefficient and forces pass via the motor
Solution Approach 1:
The damping function is extracted from the electric actuator and implemented as a separate hydraulic damper system. This allows the damper to function independently without involving the motor and ball screw mechanism, eliminating the problem of forces passing through the motor and improving both efficiency and reliability
Solution Approach 2:
The solution copies the successful hydraulic damping principle from traditional hydraulic rams and applies it to electric actuator systems. By replicating the hydraulic damper design proven effective in hydraulic systems, the invention achieves reliable shock damping while maintaining the advantages of electric actuation
3Reliability
If elastomer-based damping solution is used in electric rams, then shock damping is provided, but significant forces are generated at the internal screw posing reliability problems
Solution Approach 1:
The invention replaces elastomer-based mechanical damping with hydraulic damping. The hydraulic damper uses fluid pressure and calibrated orifices to dissipate energy, providing effective shock damping without generating excessive forces on the internal screw and ball mechanism, thereby improving reliability
4Loss of energy
If mechanical deformation-based damping is used, then shock absorption is achieved, but the solution is bulkier and cannot be used more than once per shock
Solution Approach 1:
The hydraulic damper is designed to automatically reset after each shock event. The fluid in the hydraulic system returns to its original state after dissipating energy, allowing the damper to be reused for subsequent shocks without manual intervention or replacement, unlike single-use mechanical deformation solutions
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 effectively dissipates energy over a minimum path, reducing structural stress and ensuring safety by isolating forces from the drive unit, allowing for adaptable damping to various load scenarios and preventing damage to the motor and reducer during extreme breakdowns.
Implementation Method 1
Hydraulic rams used principally in heavy industry to move loads in excess of fourteen tons generally incorporate hydraulic shock dampers. These latter function by converting kinetic energy into thermal energy by pressurizing fluid through calibrated orifices or in cones.
Implementation Method 2
They progressively compress a volume of oil in such a manner as to progressively absorb significant levels of energy, to dissipate said levels of energy and to decelerate a constant force with constant deceleration
Data Source
AI summary
A device that makes it possible to make the movements of moving platforms safer and relates more particularly to a linear actuator that can be used in a hexapod positioner supporting a load is provided. The actuator is actuated by electric control and comprises at least one hydraulic damper positioned on the actuator such that the forces generated by damping in the event of extreme breakdown are experienced only by the load and are distributed such as to limit force and acceleration peaks.