Elevator Car Centering via Independent Friction Wheel Speed Control
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Solution Overview
Problem
The existing construction phase elevator systems are not suitable for high-speed operations, which are required for final elevator systems in tall buildings, as they lack the necessary driving speed and efficiency, and they require frequent adjustments to maintain operational efficiency during the construction phase.
Innovation Solution
A self-driving construction phase elevator system with a winding cabin that adapts to increasing elevator shaft height, using a guide rail strand and a drive system that can be extended, allowing for high-speed transportation of people and materials during construction and later converted into a final elevator system with enhanced drive components for increased speed and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a self-propelled construction phase elevator car with rack and pinion drive is used, then the usable lifting height can be adapted to increasing building height, but the travel speed is insufficient for high-speed elevator requirements
Solution Approach 1:
The patent applies dynamics by making the guide system and rack length adjustable during construction phase to adapt to increasing building height, while transitioning to a fixed high-speed drive system (friction wheels or linear motor) for the final elevator system. This dynamic adaptation resolves the contradiction between height adaptability and speed performance.
Solution Approach 2:
The patent changes drive system parameters by transitioning from rack-and-pinion with limited speed capability to friction wheel drive or linear motor drive with higher speed capability. The guide system parameters are also adjusted from temporary construction phase configuration to permanent final system configuration, resolving the speed limitation.
2Speed
If friction wheels are used for high-speed operation, then travel speed requirement is met, but centering of the elevator car becomes problematic
Solution Approach 1:
The patent implements feedback by using sensors to detect the elevator car's position relative to the guide rail and using this information to control the rotational speeds of friction wheels differently on each side. This closed-loop control system corrects centering deviations while maintaining high travel speed.
Solution Approach 2:
The patent applies asymmetry by allowing the rotational speeds of the friction wheels on opposite sides of the elevator car to be controlled independently and asymmetrically. This enables differential speed control to correct centering issues without compromising the overall high-speed performance of the elevator system.
3Adaptability or versatility
If the guide system and rack are extended during construction phase, then the elevator can accommodate increasing building height, but the system complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the guide system into modular sections that can be extended in steps during construction phase. The rack is also segmented to allow incremental lengthening. This modular approach reduces complexity compared to a single large adjustable system, while still achieving height adaptability.
Solution Approach 2:
The patent implements preliminary action by installing the guide system and rack with initial length sufficient for construction phase, then extending them as needed. The system is prepared in advance to accommodate future height increases, reducing the need for complete system replacement and simplifying the overall process.
4Manufacturing precision
If independent rotational speed control of friction wheels is implemented, then elevator car centering is improved, but the control system complexity increases
Solution Approach 1:
The patent uses feedback control where sensors detect car position and this information feeds back to the control system, which adjusts the rotational speeds of individual friction wheels. This automated feedback loop achieves precise centering without requiring complex manual control mechanisms.
Solution Approach 2:
The patent implements self-service by enabling the elevator car's own drive system (friction wheels with independent speed control) to perform the centering function. The car self-corrects its position using its drive components, eliminating the need for separate centering mechanisms and reducing overall system complexity.
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 solution provides an optimal elevator system during construction with reduced downtime and costs, enabling efficient transportation and allowing for the installation of a high-speed final elevator system without the need for a shiftable machine room, ensuring smooth transitions from construction to completed building operations.
Implementation Method 1
a drive system which has a primary part attached to the elevator car and a secondary part attached along the travel path, wherein the primary part of the drive system mounted for driving the elevator car comprises a plurality of driven friction wheels, wherein the elevator car is driven by an interaction of the driven friction wheels with the secondary part of the drive system
Data Source
Figure 1~2
Figure 3A~3B
Figure 4A~4B
AI summary
The invention relates to a method for centring a lift cabin in a lift installation, wherein the lift installation comprises a self-propelled lift cabin. At least two driven friction wheels are in each case pressed against each of two opposing guide surfaces of a first guide rail track and of a second guide rail track to drive the lift cabin, a first rotational speed of the friction wheels which act on the first guide rail track, and a second rotational speed of the friction wheels which act on the second guide rail track being adjustable independently of one another. The first guide rail track lies in a first plane and the second guide rail track lies in a second plane, extending substantially parallel to the first plane. A centre point of the lift cabin in a centred state is located on a central plane extending in parallel to the first and second planes. When a deviation of the centre point from the centre plane is detected, the first rotational speed and/or the second rotational speed are modified in such a manner that the centre point moves towards the centre planes upon a movement of the lift cabin along the travelway.