Counterweight-Mounted Gearless Drive for Elevator Space and Noise

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Solution Overview

Problem

Existing elevator designs face challenges with noise transmission, limited space utilization, and complex maintenance due to large drive components, which restrict optimal use of the elevator shaft and complicate emergency rescues.

Innovation Solution

A cylindrical drive with an external rotor sleeve is positioned on the counterweight, aligned parallel to the car wall, allowing for a smaller diameter and reduced axial extension, enabling efficient space use and minimizing noise transmission, while a gearless design with a rotating outer rotor sleeve and stator provides the necessary drive power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the drive is mounted on the upper end of the elevator shaft, then the drive can be positioned in a narrow space between shaft wall and car wall, but the drive diameter becomes large (at least 800 mm) and noise is transmitted into the shaft

Engineering Contradiction:
Improveshaft space utilizationVSAvoidnoise transmission
Core Design Contradiction:
Area of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent inverts the conventional mounting location by placing the drive on the counterweight instead of on the upper shaft end. This inversion allows the drive to be positioned in a quiet zone away from the shaft, eliminating noise transmission while maintaining compact dimensions through the cylindrical motor design with axial orientation.

Inventive Principle:
Principle #13The other way round (Inversion)

2Power

If the drive diameter is increased to handle larger load capacities, then the drive power increases, but the axial space requirement increases and guide rail arrangement is restricted

Engineering Contradiction:
Improvedrive powerVSAvoidaxial dimension
Core Design Contradiction:
PowerVSLength of moving object

Solution Approach 1:

The patent transitions from radial power transmission (where power increases with diameter) to axial power transmission. The cylindrical motor generates torque along its axis, and this axial torque is transmitted to the rope through a pulley system. This dimensional change allows high power output without increasing axial dimensions, as the motor's length along the axis remains compact regardless of power capacity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If the drive unit is mounted on the cabin with brake, then emergency release can be implemented mechanically, but the drive unit requires large axial and radial dimensions and protrudes laterally requiring large free shaft area

Engineering Contradiction:
Improveemergency releaseVSAvoidfree shaft area
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

The patent extracts the drive unit from the cabin and relocates it to the counterweight. This separation removes the large-dimensional drive components from the cabin assembly, eliminating the need for large free shaft area laterally. The emergency release function is maintained through the brake system on the counterweight, which can be mechanically actuated without requiring the drive to protrude into the shaft space.

Inventive Principle:
Principle #2Taking out (Extraction)

4Area of stationary object

If frictional power transmission from drive roller to guide profile is used, then the drive does not require large area, but frictional losses occur and drive roller becomes unbalanced causing running irregularities and noise

Engineering Contradiction:
Improvedrive areaVSAvoidrunning stability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent replaces the friction-based mechanical transmission with a positive engagement system. Instead of relying on friction between the drive roller and guide profile, the system uses a toothed rack and pinion mechanism where the pinion gear engages positively with the rack. This substitution eliminates frictional losses, prevents drive roller unbalance, and ensures reliable power transmission without running irregularities or noise.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 optimizes space usage, reduces noise, and simplifies maintenance and emergency rescues by allowing the drive to contribute to the counterweight, enabling a more compact and efficient elevator system with improved access and reduced material usage.

Implementation Method 1

a cylindrical drive with an external rotor sleeve is positioned on the counterweight, aligned parallel to the car wall, allowing for a smaller diameter and reduced axial extension, enabling efficient space use and minimizing noise transmission, while a gearless design with a rotating outer rotor sleeve and stator provides the necessary drive power

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP1882668B1Elevator with motor placed in the counterweight
Publication Date: 2023.08.30 DIETHELM HANSRUEDI
  • EP1882668B1 patent drawingFigure 1~3
  • EP1882668B1 patent drawingFigure 4~5

AI summary

The lift has a cabin (3), which has cabin walls and a cabin door at a front side, comprising a first guide device (6) for guiding the cabin movement. The drive (10) is arranged at the counter weight (7) and its drive axis runs parallel to a plane through the cabin wall facing the counter weight. The drive is gearless and comprises an outer runner sleeve (11) around the drive axis. The diameter of the outer runner sleeve is smaller than the extension of the drive towards the drive axis and the rope (9) runs with an enlacement of 180 degrees around the outer runner sleeve.