Elevator Traction Machine Using Friction Roller Shafts
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Solution Overview
Problem
Conventional traction-based elevator systems for high-rise applications require large, expensive, and heavy machines to provide sufficient torque for the drive sheave, which is inefficient and costly.
Innovation Solution
A machine assembly that includes roller shafts with traction rollers, where the friction between the rollers and a drive sheave reduces the torque requirement, allowing for a smaller and lighter motor, and the use of a support structure to position the machine assembly within the hoistway, eliminating the need for a separate machine room.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a larger traction sheave is used to support stronger traction members for high-rise applications, then the torque requirement increases, but the machine size, weight, and cost increase
Solution Approach 1:
A friction wheel is introduced as an intermediary component between the motor and the traction sheave. The friction wheel contacts the traction sheave and transmits rotational motion through friction, allowing the motor to drive the traction sheave indirectly. This intermediary mechanism enables torque transmission while using a smaller, lighter motor compared to direct drive configurations.
Solution Approach 2:
The patent replaces the traditional direct mechanical connection (gear drive or belt drive) with a friction-based contact system. The friction wheel creates a frictional contact with the traction sheave, substituting complex mechanical transmission components with a simpler friction-based system that reduces overall machine weight and complexity.
2Power
If conventional traction machines are used for high-rise applications, then sufficient torque is provided, but the machine room requirement increases space and cost
Solution Approach 1:
The friction wheel serves as a mediator that enables compact power transmission. By using friction-based contact between the friction wheel and traction sheave, the system achieves effective torque transmission in a more compact configuration, reducing or eliminating the need for a separate machine room.
Solution Approach 2:
The patent merges the motor, friction wheel, and traction sheave into a more integrated assembly. The friction wheel is positioned to contact the traction sheave, combining multiple functional elements into a compact unit that reduces the overall space requirement and eliminates the need for a dedicated machine room.
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 configuration reduces the weight and cost of the motor while maintaining efficient operation, allowing for a cost-effective solution for high-rise elevator systems by minimizing the torque needed to move the elevator car and counterweight.
Implementation Method 1
roller shafts (54) having a diameter substantially smaller than the diameter of the drive sheave (52)... configured to support the weight of the drive sheave (52)... a friction transmitting rotor... the friction generated between the rotating roller shafts (54) or traction rollers (56) and the drive sheave (52) causes the drive sheave (52) to rotate
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A machine assembly for use in an elevator system is provided including a drive sheave (52) configured to rotate about a first axis of rotation (R). A first roller shaft (54) is configured to rotate about a second axis of rotation (S) substantially parallel to the first axis of rotation. Rotation of the first roller shaft about the second axis of rotation is configured to rotate the drive sheave about the first axis of rotation. A first motor is operably coupled to the first roller shaft and is configured to rotate the first roller shaft about the second axis of rotation.