Planetary Brake Assembly for Compact Access Control Barriers
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Solution Overview
Problem
Conventional electromechanical shaft brakes in access control systems face challenges such as high cost, misalignment issues, noise, and high power consumption due to the need for significant braking torque and precise engineering, particularly in space-constrained applications like slim side walls, where they must provide high braking force while minimizing size and noise.
Innovation Solution
The access control system employs a brake assembly with a sun gear, carrier, and ring gear, along with planet gears, which reduces the torque required for braking by using a gear ratio that allows the sun gear to rotate faster than the shaft, enabling a smaller brake size and lower power consumption, and allows for easy adjustment of the brake gap without additional components like spring plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the diameter of the brake is increased to provide higher braking torque, then the braking torque increases, but the brake size increases which is not acceptable in space-constrained applications
Solution Approach 1:
A flexible membrane is introduced as an intermediary between the electromagnetic actuator and the brake components. This membrane transmits the magnetic force generated by the electromagnet to the armature and friction surface, enabling force multiplication without increasing the overall brake diameter. The membrane's flexibility allows it to conform to the curved surface and distribute the force effectively across the braking interface.
Solution Approach 2:
The invention changes the physical state and properties of the membrane material to achieve high force transmission in a compact form. By selecting a membrane material with appropriate elasticity and tensile strength, the system can generate high braking torque from a small electromagnetic actuator. The membrane's ability to store and release elastic energy contributes to the force multiplication effect.
2Force
If conventional electromechanical shaft brakes are used to provide high braking torque, then the braking torque is sufficient, but the cost increases due to precision engineering requirements
Solution Approach 1:
The invention replaces expensive precision-engineered metal components with a simpler, more cost-effective membrane-based system. The flexible membrane can be manufactured using cheaper materials and processes such as rubber or polymer extrusion, eliminating the need for precision machining of metal brake components. The simplified design reduces manufacturing complexity and cost while maintaining adequate braking performance.
3Force
If metal components are used in the brake structure to achieve high braking torque, then the braking torque is sufficient, but noise increases due to mechanical snap when components contact each other
Solution Approach 1:
The invention uses a composite structure combining a flexible membrane with friction surfaces, replacing traditional metal-on-metal contact. The membrane material (such as rubber or polymer) provides both structural integrity and damping properties that reduce impact noise. The combination of flexible membrane and friction material creates a quieter braking action while maintaining sufficient stopping force.
4Force
If the working gap of the brake is made small to ensure proper engagement, then the braking torque increases, but the complexity of setup and adjustment increases
Solution Approach 1:
The flexible membrane automatically adjusts to the correct working gap through its elastic properties. When the brake is assembled, the membrane's natural tension and flexibility cause it to conform to the curved surface and establish the optimal engagement distance without manual adjustment. The membrane self-regulates the gap based on the applied force and geometric constraints, eliminating the need for precision setup procedures.
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 configuration significantly increases braking torque without increasing the brake's size, reduces power consumption, and provides quieter operation by using a less powerful electromagnet and plastic gear components, while ensuring easy setup and alignment, resulting in a more efficient and cost-effective access control system.
Implementation Method 1
Electromechanical shaft brakes comprise a moving magnetic component referred to as an armature, which, when drawn by magnetic force to engage with a corresponding surface of an electromagnet, provides braking torque to an attached torque load.
Data Source
AI summary
An access control system for restricting access through a passageway includes a shaft rotatable about a central axis; a barrier fixed to the shaft to rotate therewith; and a brake assembly. The brake assembly includes a sun gear rotatable about the central axis, a carrier, and a ring gear, wherein one of the carrier or the ring gear is fixed against rotation and the other of the carrier or ring gear is connected to the shaft to rotate therewith. A plurality of planet gears are rotatably connected to the carrier, each planet gear being disposed between and engaging with each of the sun gear and the ring gear. An electromagnetic brake comprises an electromagnet and an armature. The armature is connected to or integral with the sun gear to rotate and move axially therewith. At least one of the electromagnet or the armature is moveable between an operative position and an inoperative position.