Elevator Emergency Stop Actuator Alignment to Reduce Motor Load

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Solution Overview

Problem

Existing elevator systems with emergency stop devices that do not use governor ropes face increased mechanical load on motors due to assembly and dimensional tolerances, leading to larger and more power-consuming motors.

Innovation Solution

An elevator device with an electric actuator that includes a movable member aligned with a guide portion and a feed screw mechanism to reduce motor load during return operations, using a solenoid or electromagnet to actuate the emergency stop device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If assembly tolerance and dimensional tolerance of the actuation mechanism are considered, then the mechanical load on the motor increases, but increasing motor output leads to increased size and power consumption

Engineering Contradiction:
ImprovereliabilityVSAvoidsize
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The guide portion is designed to align the movable member with the electromagnet before the movable member reaches its final position. This preliminary alignment compensates for assembly and dimensional tolerances, preventing excessive mechanical load on the motor during the return operation and eliminating the need for oversized motors

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If assembly tolerance and dimensional tolerance of the actuation mechanism are considered, then the mechanical load on the motor increases, but increasing motor output leads to increased power consumption

Engineering Contradiction:
ImprovereliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The guide portion aligns the movable member with the electromagnet in advance, compensating for tolerances before the return operation completes. This prevents excessive mechanical load that would require higher motor output, thereby reducing power consumption while maintaining reliable operation

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

The electric actuator reduces motor load during return operations by aligning the movable member with the electromagnet, preventing increased motor output requirements and improving reliability.

Implementation Method 1

an electromagnet portion to which the movable member is attracted

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnet

Implementation Method 2

a feed screw, a motor that rotates the feed screw, and a feed nut provided on the electromagnetic core and screwed with the feed screw

Methodology Applied
Scientific EffectScrew mechanism: Screw

Data Source

PatentEP4328166B1Elevator apparatus
Publication Date: 2026.04.01 HITACHI LTD
  • EP4328166B1 patent drawingFigure 1
  • EP4328166B1 patent drawingFigure 2~3
  • EP4328166B1 patent drawingFigure 4~5

AI summary

There is provided an elevator device including an emergency stop device operated by an electric actuator capable of reducing a load applied to a motor. The elevator device includes an elevator car; an emergency stop device; a drive mechanism (12 to 19) that drives the emergency stop device; and an electric actuator (10) that operates the drive mechanism, in which the electric actuator includes an operation lever (11) connected to the drive mechanism, a movable member (34A, 34B) that is rotatably connected to the operation lever, an electromagnet portion (35) that attracts the movable member in a standby state of the electric actuator, a feed screw (36) that is screwed with the electromagnet portion, a motor (37) that drives the feed screw, and a guide portion (201) that, in a return operation of the electric actuator, causes the movable member to follow a movement of the electromagnet portion such that the movable member is aligned with respect to the electromagnet portion when the electromagnet portion comes into contact with the movable member by being moved toward the movable member by driving the feed screw using the motor.