Flipper Arm Drive Using Self-Locking Worm Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flipper arm systems in container spreaders face challenges in managing moderate power requirements for pivoting and significant external loads during container positioning, often necessitating oversized hydraulic drives for safety and stability.
Innovation Solution
A flipper arm drive system utilizing a self-locking worm drive and an electric motor with a power transmission mechanism that transfers torque efficiently, allowing the flipper arm to lock in position without continuous motor power, and an optional parking brake to prevent external forces from affecting the power supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydraulic power systems are used to power the flipper arm, then the flipper arm can be held in position and withstand external loads, but the power system becomes oversized due to the need to handle both moderate pivoting power and considerable external loads
Solution Approach 1:
The system separates the functions of positioning and load-bearing. The electric motor with worm drive handles positioning, while the self-locking mechanism and optional parking brake handle load-bearing, allowing each component to be appropriately sized for its specific function rather than requiring an oversized hydraulic system for both functions
Solution Approach 2:
The patent replaces the hydraulic power system with an electric motor and worm drive mechanism. The worm drive provides inherent self-locking capability that prevents back-driving from external loads, eliminating the need for continuous hydraulic pressure to maintain position and withstand external forces
2Reliability
If hydraulic power systems are continuously pressurized to power flipper arm movements and holding, then the flipper arm can be reliably positioned and held, but energy is continuously consumed even when the flipper arm is stationary
Solution Approach 1:
The worm drive mechanism provides self-locking capability, allowing the flipper arm to maintain its position without continuous power input. The mechanism automatically prevents back-driving from external loads, enabling the system to hold position using its own mechanical structure rather than continuous energy input
Solution Approach 2:
The electric motor operates only periodically during positioning operations rather than continuously. Once the flipper arm reaches the desired position, the motor can be de-energized while the worm drive maintains the position, significantly reducing energy consumption compared to continuous hydraulic pressurization
3Strength
If the flipper arm is designed to withstand considerable external loads from container contact, then the spreader connection is secure, but the power transmission components must be oversized to handle these loads
Solution Approach 1:
The patent extracts the load-bearing function from the power transmission system. The worm drive and shaft are designed only for positioning, while the self-locking mechanism and optional parking brake extract and handle the load-bearing function, allowing the power transmission components to be smaller and simpler
Solution Approach 2:
The self-locking worm drive acts as an intermediary between the electric motor and the flipper arm. It transfers positioning torque from the motor while simultaneously providing mechanical locking to withstand external loads, protecting the motor and power transmission components from direct exposure to container contact forces
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 solution reduces the size and power requirements of the motor, protects the power system from external loads, and enables precise positioning of the spreader relative to the container, enhancing operational safety and efficiency.
Implementation Method 1
the power transmission between the motor and the flipper arm comprises a self-locking worm drive including a worm screw driven by the motor and tangentially engaged by a gear-wheel carried on the rotatable shaft
Implementation Method 2
the pitch of threads are chosen to permit the gear-wheel to be rotated by the worm screw while preventing the worm screw from being rotated by the gear-wheel
Data Source
AI summary
The present invention relates to an arrangement on a spreader for lifting containers, the arrangement comprising a flipper arm which is supported at the corner of the spreader such that the flipper arm is pivotable between an upraised rest position and a lowered operative position wherein the flipper arm is effective for positioning of the spreader corner relative to the corresponding corner of a container upon connecting the spreader to the container. The arrangement is characterized in that the flipper arm is carried on a rotatable shaft and driven by a motor, and wherein a power transmission is inserted between the motor and the flipper arm, the power transmission being effective for the transfer of torque from the motor to the flipper arm upon energizing the motor, and operative for locking the flipper arm in its pivoted position upon non-energizing the motor.