Miniature Brake Assembly With Cavity-Bonded Pressure Plate
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Solution Overview
Problem
Conventional electromagnetic brakes are limited in size due to the use of fasteners, which restrict the miniaturization of brakes and the generation of high braking torque, and often contaminate friction surfaces with thread locking adhesives.
Innovation Solution
The brake is assembled without conventional fasteners by using a fastener that bonds the pressure plate to the electromagnet, allowing for a compact design with a precise air gap and efficient assembly, eliminating the need for thread locking adhesives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional fasteners (threaded fasteners, bolts, pins) are used to couple brake components, then the brake structure is mechanically strong and easy to assemble, but the brake size cannot be reduced below a certain minimum due to fastener dimensions and handling requirements
Solution Approach 1:
The patent removes conventional fasteners (threads, bolts, pins, swaging, press fits) from the brake assembly process. Instead, it uses a fastener material that is deposited or injected into a cavity between the pressure plate and electromagnet, where it cures to form a bond. This extraction of traditional fastening mechanisms eliminates the minimum size constraints imposed by conventional fastener dimensions and handling requirements.
Solution Approach 2:
The patent replaces the mechanical fastening system (threads, bolts, pins) with a chemical bonding system. A fastener material (such as adhesive or epoxy) is introduced into the cavity and cures to create a mechanical bond between components. This substitution eliminates the need for threaded holes, bolt heads, and pin interfaces, thereby reducing the overall brake volume while maintaining assembly capability.
2Strength
If conventional fasteners are used to couple brake components, then the components are securely joined, but the space required by fasteners limits the size of electromagnetic components and reduces braking torque capability
Solution Approach 1:
The patent extracts conventional fasteners from the assembly, removing the space they would occupy between the pressure plate and electromagnet. This freed space allows for larger electromagnetic components (coil, magnet, armature) which can generate higher braking torque. The fastener material is contained within a specifically designed cavity, preventing it from interfering with electromagnetic component sizing.
Solution Approach 2:
The fastener material is nested within a cavity formed between the pressure plate and electromagnet. This nesting approach allows the fastening function to be embedded within the existing component structure rather than adding external fasteners. The cavity is designed to accommodate the fastener material in its uncured state, and upon curing, the fastener becomes an integral part of the joint structure, maximizing space utilization for electromagnetic components.
3Reliability
If conventional fasteners with thread locking adhesives are used, then the joint is secure and resistant to loosening, but the adhesives contaminate the friction surfaces and degrade braking performance
Solution Approach 1:
The patent extracts the harmful thread locking adhesive function from the friction surface area. Instead of applying adhesive to the friction surfaces of the friction plate, the adhesive (fastener material) is introduced into a dedicated cavity between the pressure plate and electromagnet. This spatial separation ensures that the adhesive cannot contaminate the friction surfaces, maintaining braking performance while still providing secure joint fixation.
Solution Approach 2:
The cavity structure acts as an intermediary barrier between the fastener material and the friction surfaces. The cavity confines the fastener material during application and curing, preventing it from migrating to the friction surfaces. This intermediary structure allows the use of strong adhesive bonding for joint reliability while protecting the friction surfaces from contamination that would degrade braking performance.
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 approach enables the creation of a small, high-torque brake with efficient assembly and prevents contamination of friction surfaces, allowing for precise component alignment and reduced tolerance stackup.
Implementation Method 1
The fastener conforms to a space between opposed surfaces of the pressure plate and the electromagnet and, upon hardening, bonds the pressure plate to the electromagnet
Implementation Method 2
a spring biasing the armature plate in a first axial direction towards the friction plate and away from the electromagnet to engage the brake
Implementation Method 3
an electromagnet disposed about the axis on an opposite side of the armature plate relative to the friction plate
Data Source
AI summary
A brake and method of assembly are provided. The brake includes a friction plate configured for coupling to a rotatable body for rotation with the rotatable body about an axis of rotation, a pressure plate disposed about the axis on a first side of the friction plate and fixed against rotation, and an armature plate disposed about the axis on a second side of the friction plate. An electromagnet is disposed about the axis on an opposite side of the armature plate relative to the friction plate. A spring biases the armature plate in a first axial direction towards the friction plate and away from the electromagnet to engage the brake. A fastener couples the pressure plate to the electromagnet. The fastener conforms to a space between opposed surfaces of the pressure plate and the electromagnet and, upon hardening, bonds the pressure plate to the electromagnet.