Elevator Cabin Door Linear Drive Mechanism Modernization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Older elevator car door systems with crank mechanisms face issues such as slow opening and closing times, high closing forces, noise, and maintenance complexity, which are not easily adaptable to special user needs like those of disabled or elderly passengers, and are costly to maintain.
Innovation Solution
The modernization kit replaces the crank mechanism with a linearly moved drive means, such as a toothed belt or pneumatic cylinder, and an actuating device for the car door/landing door coupling, allowing for controlled speed and torque adjustments and reducing maintenance efforts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a crank mechanism with drive linkage is used to move the car door leaf, then the door system provides mechanically robust operation with defined end positions, but the opening and closing time is prolonged and cannot be optimized for special user needs
Solution Approach 1:
The patent replaces the traditional crank mechanism with a linearly moving drive means (such as a linear motor or pneumatic cylinder) that directly moves the car door panel along a linear path. This substitution eliminates the complex crank arms, connecting rods, and lever joints, enabling optimized speed profiles for faster door operation while accommodating special user needs without being constrained by mechanical geometry
Solution Approach 2:
The linearly moving drive means enables dynamic control of the door speed profile, allowing acceleration and deceleration to be optimized at different phases of door movement. This dynamic control permits faster overall operation while providing gentle acceleration for disabled or elderly passengers, something impossible with the fixed sinusoidal speed profile of a crank mechanism
2Reliability
If a crank mechanism is used to generate door movement, then the door achieves complete opening/closing movement, but extremely high closing forces are generated shortly before the closed position which can lead to trapping accidents
Solution Approach 1:
Replacing the crank mechanism with a linearly moving drive means eliminates the geometric constraint that causes force multiplication near the closed position. The linear drive can maintain constant or controlled force throughout the door stroke, preventing the extremely high closing forces that occur when the crank arm approaches its dead center position, thereby improving safety and enabling effective obstacle detection
Solution Approach 2:
The linearly moving drive means enables implementation of feedback control systems that monitor door position and force, allowing the drive to detect obstacles and reverse direction or hold position when resistance is encountered. This feedback capability is essential for preventing trapping accidents and is not feasible with the open-loop mechanical crank system
3Object-affected harmful factors
If a crank mechanism with countershaft and drive linkage is used, then the door drive provides mechanical advantage, but considerable noise is generated which is hardly acceptable in today's elevator systems
Solution Approach 1:
The patent replaces the noisy mechanical crank mechanism with a linearly moving drive means that operates with significantly reduced mechanical contact and friction. Linear motors or pneumatic cylinders generate motion through electromagnetic or pneumatic fields rather than through sliding and rotating mechanical components, thereby eliminating the considerable noise generated by crank arms, connecting rods, and lever joints while maintaining the necessary mechanical advantage
4Ease of repair
If a mechanically complex door drive with crank mechanism is used, then the door system provides robust operation, but considerable effort is required for checking, maintenance and readjustment
Solution Approach 1:
The linearly moving drive means eliminates multiple mechanical components (crank arms, connecting rods, lever joints, motor brakes) that require periodic maintenance, lubrication, and adjustment. With fewer moving parts and no mechanical transmission elements subject to wear, the system dramatically reduces maintenance effort while improving reliability and ease of repair
Solution Approach 2:
The simplified linear drive system requires minimal intervention and can operate for extended periods without maintenance. The absence of friction-prone mechanical joints and the ability to use electronic or pneumatic control systems that have no wear parts enable the system to largely service itself, reducing the considerable effort previously required for checking, maintenance, and readjustment
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 achieves faster door operation, safer closing forces, reduced noise, and adaptability to special conditions without replacing existing door panels or couplings, thus minimizing costs and effort.
Implementation Method 1
a door drive with a linearly moved drive means... driving at least one of the drive means disks and thus also the linearly moving drive means
Implementation Method 2
a flexible traction means, for example in the form of a toothed belt, guided and driven by drive means disks
Data Source
Figure 1A~1C
Figure 2A~2B
Figure 3A~3B
AI summary
The method involves dismantling the door actuator with the crank drive and the driving rod assembly. The door actuator is installed with a linearly moving drive unit (16 4) and is coupled with the cabin leaf (5) of the original cabin door system. The actuation equipment (17) is installed for the manipulation of the cabin door or shaft door clutch (8). The linearly moving drive unit is used as a flexible drawing unit propelled by driving pulleys. The flexible drawing unit is a toothed belt or a burl belt or a link chain. Independent claims are also included for the following: (1) modernization kit (2) elevator cabin.