Variable-Ratio Gear Actuator for Uniform Barrier Torque
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motorized drives for movable barriers, such as doors and gates, experience non-uniform torque requirements during opening and closing, leading to inefficient motor usage and kinematic systems with high gear ratios, which can be reduced by making the torque and speed profiles more uniform.
Innovation Solution
A motorized drive with a reduction unit featuring a first and second toothed profile that engage to form a gear with a variable transmission ratio, where at least one of the profiles has a non-circular pitch profile, allowing for a more uniform torque application throughout the movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a conventional electric motor with constant torque is used to operate the wing, then the motor can deliver high torque during acceleration and deceleration phases, but the motor operates inefficiently during the intermediate phase where only low torque is needed to overcome friction
Solution Approach 1:
The patent applies a variable transmission ratio mechanism that dynamically adjusts the torque-speed relationship between the motor and the wing. During acceleration and deceleration phases, the transmission ratio provides mechanical advantage for high torque; during the intermediate constant-speed phase, the ratio adjusts to reduce motor torque requirements, allowing the motor to operate more efficiently across the entire motion cycle
Solution Approach 2:
The transmission ratio is changed as a variable parameter throughout the motion cycle. By modifying the transmission ratio according to the specific phase of motion (acceleration, constant speed, deceleration), the system optimizes motor performance and energy efficiency for each operational condition
2Force
If a high gear ratio reduction system is used to provide sufficient torque for acceleration and deceleration, then the motor can overcome the wing's weight and inertia, but the kinematic system becomes more complex and massive
Solution Approach 1:
Instead of using a fixed high gear ratio that increases system complexity and mass, the patent employs a variable transmission ratio mechanism. This allows the system to provide high torque only when needed (during acceleration and deceleration) while using lower effective ratios during constant-speed operation, thereby reducing overall system complexity and mass requirements
3Ease of manufacture
If the transmission ratio is kept constant throughout the motion, then the reduction unit is simpler to manufacture, but the motor must be oversized to handle peak torque requirements during acceleration and deceleration
Solution Approach 1:
The patent changes the transmission ratio parameter throughout the motion cycle rather than keeping it constant. This allows the motor to be sized for average power requirements rather than peak torque requirements, reducing motor rated power while the variable transmission mechanism handles the peak torque demands during acceleration and deceleration phases
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 results in a more efficient motor operation with reduced power requirements and lighter, less massive motorized drives, achieving a wider range of speed profiles and torque adjustments, while minimizing vibrations and noise.
Implementation Method 1
a reduction unit (9), comprising a first (11) and second (13) toothed profile that engage one another, forming a gear with a variable transmission ratio
Data Source
AI summary
The motorized drive according to the invention application is configured to open and/or close a wing of a barrier such as a door, main door, gate or swing shutter, a wall or sliding partition or other sliding wing. The motorized drive comprises includes a motor and a first reduction unit through which the motor can open or close the wing. The reduction unit comprises includes a first and a second toothed profile engaging together, thus realizing a gear with a variable transmission ratio depending on the angular and/or linear position of at least one of the two toothed profiles. At least one of the first and of the second toothed profile forms at least one toothed section having a pitch profile which is substantially non-circular or not formed by a simple arc of a circle or a straight line.