Gearless Elevator Car Sheave Rope Routing for Multi-Car Hoistway

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Traditional elevator systems face challenges when operating multiple elevator cars in the same hoistway, requiring additional components like counterweights and additional space, which complicates installation and operation.

Innovation Solution

The elevator system employs gearless prime movers, such as hub wheel motors, connected to sheaves with parallel axes of rotation, and load bearing members that pass under and over the sheaves, allowing for independent operation of multiple elevator cars within a single hoistway without a separate machine room or counterweight, using tension offset devices to manage rope tension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional traction arrangement with drive machine and drive sheave is used, then elevator car can be moved along hoistway, but additional components like counterweight are required and multiple elevator cars cannot operate in same hoistway

Engineering Contradiction:

ImproveAbility to operate multiple elevator cars in same hoistwayVSAvoidNumber of additional components required

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system divides the traditional centralized drive mechanism into distributed drive units, with each elevator car having its own prime mover. This segmentation allows multiple independent cars to operate in the same hoistway without requiring shared counterweights or complex traction arrangements, directly resolving the contradiction between versatility and device complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention extracts and removes the counterweight component from the system entirely. By using self-propelled cars with onboard prime movers, the counterweight is no longer needed, simplifying the system and enabling multiple cars to share the same hoistway without the complications of traditional counterweight arrangements

Inventive Principle:

Principle #2Taking out (Extraction)

2Ease of operation

If rack and pinion arrangement with linear induction motors is used, then self-propelled operation is achieved, but additional components and space requirements remain

Engineering Contradiction:

ImproveSelf-propelled operation capabilityVSAvoidSpace requirements in hoistway

Core Design Contradiction:

Ease of operationVSArea of stationary object

Solution Approach 1:

The invention merges the prime mover and drive functions directly into the elevator car structure itself. By integrating the prime mover within the car and combining it with the load bearing member arrangement, the system eliminates the need for separate machine rooms and extensive hoistway infrastructure, reducing space requirements while maintaining self-propelled operation

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The system transitions from traditional horizontal/vertical space utilization to a configuration where the load bearing members extend diagonally from the car. This dimensional change allows the prime mover and drive mechanism to be compactly arranged within the car structure, reducing the footprint required in the hoistway

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 enables efficient vertical movement of multiple elevator cars in a shared hoistway, reducing space requirements, installation costs, and allowing for flexible operation, including simultaneous service to multiple floors and high-rise applications, while maintaining ride quality and load capacity.

Implementation Method 1

a gearless prime mover operably connected to the traction surface to drive rotation of the traction surface

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

The first load bearing member passes laterally under the first sheave, vertically upward between the first sheave and the second sheave, and laterally over the second sheave

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS11434107B2Rope-climbing self propelled elevator system

Publication Date: 2022.09.06 OTIS ELEVATOR CO

AI summary

An elevator system includes a hoistway and an elevator car positioned in and movable along the hoistway. The elevator car includes a first sheave and a second sheave spaced apart from the first sheave. The first sheave and second sheave have parallel axes of rotation and each include a traction surface and a gearless prime mover operably connected to the traction surface to drive rotation of the traction surface. A first load bearing member is positioned in the hoistway and a second load bearing member is positioned in the hoistway. The first load bearing member passes laterally under the first sheave, vertically upward between the first sheave and the second sheave, and laterally over the second sheave. The second load bearing member passes laterally under the second sheave, vertically between the second sheave and the first sheave, and laterally over the first sheave.