Hoisting Machine Damping via Adjustable Cover Plates
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Solution Overview
Problem
Vibration and noise issues in axial flux motors used in elevator hoisting machines are challenging due to the open rotor compartment and the need for cooling, which compromises rigidity and increases noise and vibration transfer.
Innovation Solution
The implementation of adjustable cover plates with dampers between the rotor and stator, and a tightness adjustment mechanism, which disperses vibrations and noise, stiffening the structure and allowing for customizable noise and vibration suppression across various frequency ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the rotor compartment is made open to enable rope movement and brake cooling, then the hoisting machine can operate with suspension ropes and cooled brakes, but vibration and noise transfer to the environment increases
Solution Approach 1:
A damping element is introduced as an intermediary component between the rotor compartment and the machine frame. This damping element absorbs and dissipates vibration energy, preventing it from being transmitted to the machine frame and radiating as noise into the environment, while still allowing the rotor compartment to remain open for rope movement and cooling
2Length of moving object
If the hoisting machine dimensions are minimized in the axial direction to fit narrow spaces, then the hoisting machine becomes more compact, but the rigidity of the hoisting machine weakens
Solution Approach 1:
The damping element is constructed as a composite structure with a viscoelastic material layer bonded to a metallic carrier plate. This composite construction provides both the rigidity needed to maintain structural integrity in a compact design and the vibration damping properties to reduce noise transmission
3Object-generated harmful factors
If vibration dampers are fitted between the stator and machine frame to reduce vibration, then vibration and noise are reduced, but the structural rigidity and stability may be compromised
Solution Approach 1:
The damping element is specifically positioned between the rotor compartment and machine frame, targeting the local source of vibration generated by the rotor and drive sheave. This localized damping approach reduces vibration and noise without requiring widespread structural modifications that would compromise overall machine rigidity
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
Significantly reduces noise and vibration over a frequency range, enhancing the structural rigidity of the hoisting machine and elevator assembly, while maintaining a compact size and preventing increased mass or material costs.
Implementation Method 1
an arrangement for damping vibration in an electric machine
Implementation Method 2
the damper is formed with a viscoelastic material
Implementation Method 3
The currents flowing in the stator windings produce in the air gap of the machine a rotating magnetic field, whose phase difference relative to the rotor magnetization creates a force effect in the direction of motion of the rotor
Implementation Method 4
The rotor and stator magnetizations together also produce a force of attraction between stator and rotor
Data Source
AI summary
A hoisting machine includes an axial flux motor including a rotor having rope grooves and arranged in rotor compartment between a body part and a protection plate, and a stator arranged against the rotor in such a manner that the rotor is separated by the stator by an air gap. The hoisting machine further includes a first cover plate and a second cover plate, arranged at opposite sides of the hoisting machine, and both being equipped with a damper. The tightness between the first cover plate and the second cover plate is adjustable. An elevator assembly and method of damping vibration of a hoisting machine are also disclosed.