Elevator Vertical Vibration Compensation via Auxiliary Motor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Elevators experience low-frequency vertical vibrations due to the elasticity of drive systems and rope materials, leading to perceptible vibrations during travel and safety concerns, especially with the increased elasticity of synthetic ropes, which were not adequately addressed by existing solutions.
Innovation Solution
An elevator system equipped with a sensor to measure vertical travel parameters, a comparator to generate error signals, and an auxiliary motor to exert vertical forces on guide rails, reducing vibrations through frictional or electromagnetic forces, and incorporating a controller with band-pass filtering and amplifiers for effective damping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If friction shoes are brought into contact with guide rails to increase damping ratio, then transient vibrations due to load fluctuations are attenuated more quickly, but this solution is only applicable to stationary elevator car and cannot solve vibration experienced by passenger in traveling car
Solution Approach 1:
The patent transitions from a static friction shoe system to a dynamic active control system. An auxiliary motor is introduced to actively counteract vibrations during travel by applying dynamic compensation forces to the guide rail, enabling the system to function effectively in both stationary and traveling states rather than being limited to static conditions only
2Manufacturing precision
If conventional re-leveling operation is performed to correct steady-state displacement, then car is brought back to landing level, but this operation excites further low frequency vibrations and presents safety risk with slow reaction time
Solution Approach 1:
The patent applies preliminary anti-action by using the auxiliary motor to proactively counteract vibrations and maintain car levelness during normal operation, preventing the need for corrective re-leveling operations. The active control system continuously compensates for displacement deviations, addressing the problem before it requires intervention that would excite additional vibrations
Solution Approach 2:
The patent replaces the mechanical re-leveling operation (which uses the main drive system) with an active control system using the auxiliary motor. This substitution allows for continuous, fine-adjustment levelness control without the vibrations and safety risks associated with engaging the main drive system during door-open conditions
3Object-affected harmful factors
If jerk compensation by rounding of travel curve is applied to reduce vibrations, then vibration amplitude is reduced, but travel time is increased and transport capacity is reduced
Solution Approach 1:
The patent replaces passive mechanical jerk compensation (rounding the travel curve) with active vibration counteraction using the auxiliary motor. This allows the main drive system to maintain optimal acceleration profiles for speed and efficiency while the auxiliary system independently handles vibration suppression, decoupling the trade-off between travel time and vibration control
4Weight of moving object
If synthetic ropes are used to replace steel ropes to reduce weight, then rope elasticity approximately doubles and fundamental frequency decreases, but this makes car much more susceptible to low frequency vertical vibrations
Solution Approach 1:
The patent introduces the auxiliary motor as an intermediary active control system that compensates for the increased vibration susceptibility of synthetic ropes. The auxiliary motor generates counteracting forces to offset the effects of rope elasticity and low fundamental frequency, enabling the use of lightweight synthetic ropes without suffering from their inherent vibration problems
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 significantly reduces vertical vibrations, eliminates the need for conventional re-leveling operations, and enhances ride quality by effectively damping low-frequency vibrations, particularly in traction elevators with synthetic ropes.
Implementation Method 1
an auxiliary motor mounted on the car to exert a vertical force on at least one of the guide rails
Implementation Method 2
an auxiliary motor mounted on the car to exert a vertical force on at least one of the guide rails
Data Source
AI summary
An elevator has a car traveling along guide rails within a hoistway and a main drive propelling the car. A sensor mounted on the car measures a vertical travel parameter of the car, a comparator compares the sensed car travel parameter with a reference value derived from the main drive, and an auxiliary motor mounted on the car exerts a vertical force on at least one of the guide rails in response to an error signal output from the comparator.