Elevator Brake Disk Damping Device for Noise Reduction
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Solution Overview
Problem
Elevator disk brakes generate significant noise due to excitation by electrical frequencies of the elevator machine motor during acceleration and deceleration, making it difficult and costly to redesign the motor to mitigate this issue.
Innovation Solution
A brake disk assembly with symmetrically biased dampers, including rollers and elastic members, that are anchored to the machine frame and can move between engaged and disengaged positions to reduce friction and noise, utilizing a controller to selectively adjust their position based on noise levels detected by a sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If disk brakes are used to hold the elevator car in place, then the elevator can be securely held at a landing, but significant noise is generated during acceleration and deceleration
Solution Approach 1:
A damper assembly is introduced as an intermediary component between the brake disk and the motor shaft. The damper includes a friction element that contacts the brake disk periphery and a damping element that absorbs vibrations. This intermediary structure reduces the transmission of vibrational noise from the brake disk to the motor shaft while maintaining the brake's holding capability.
Solution Approach 2:
The damper assembly is pre-installed and pre-positioned between the brake disk and motor shaft before operation. The damping element is pre-compressed or pre-positioned to provide immediate vibration absorption and noise reduction when the brake operates, preventing noise generation rather than addressing it after the fact.
2Object-generated harmful factors
If the elevator machine motor is re-designed to avoid causing disk brake excitation, then noise can be reduced, but the re-design is difficult and costly
Solution Approach 1:
The noise reduction function is extracted from the motor design and placed into a separate, independent damper assembly. Instead of modifying the motor to avoid excitation, the solution extracts the vibration absorption function into a dedicated damping component that can be added to existing motor-brake systems without re-designing the motor itself.
Solution Approach 2:
The noise control function is segmented from the motor system and implemented as a separate damper assembly with distinct friction and damping elements. This segmentation allows the motor to remain unchanged while the separate damper component handles vibration absorption, avoiding the complexity of integrated motor re-design.
3Object-generated harmful factors
If dampers are added to reduce noise, then noise levels decrease, but the device complexity increases
Solution Approach 1:
The damper assembly is merged with the existing brake disk structure, where the friction element is positioned to contact the brake disk periphery and the damping element is integrated into the same assembly. This merging approach consolidates multiple functions (friction engagement and vibration damping) into a single integrated component rather than adding separate independent systems.
Solution Approach 2:
The damper assembly serves multiple functions simultaneously: it provides friction engagement to control brake disk movement, absorbs vibrations through the damping element, and reduces noise transmission. This multi-functionality consolidates several protective and control functions into one component, reducing the need for additional separate devices.
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 reduces noise levels from approximately 90 decibels to 70-80 decibels without requiring substantial re-design of the elevator machine motor, minimizing friction and maintaining operational efficiency.
Implementation Method 1
an elastic member coupled at a first end thereof to the base and at a second end thereof to the machine frame
Implementation Method 2
dampers which are respectively anchored to the machine frame and biased to symmetrically hold the brake disk during rotations thereof
Implementation Method 3
the dampers generate negligible friction with the brake disk
Data Source
AI summary
An elevator brake disk assembly is provided. The elevator brake disk assembly includes a brake disk which is keyed to and rotatable with a shaft of an elevator machine, a machine frame and dampers. The dampers are respectively anchored to the machine frame and biased to symmetrically hold the brake disk during rotations thereof.