Elevator Hoist Bearing Lubrication for Dry Start-Up and Overheating

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Solution Overview

Problem

Elevator hoist machine bearings experience reduced life due to incomplete lubrication during start-up and increased friction and wear from high temperatures in oil bath lubrication systems, leading to premature failure and maintenance challenges.

Innovation Solution

An automatic lubrication system that delivers oil to the bearings upon brake release, providing mixed film or elastohydrodynamic lubrication before start-up and during operation, with a timer-controlled oil delivery and drainage to maintain optimal oil levels and temperature, reducing wear and overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If oil bath lubrication is used for elevator bearings, then film-forming capacity and mixed film lubrication are improved, but temperature increase and friction during start-up worsen

Engineering Contradiction:
Improvebearing lifeVSAvoidoil temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The lubrication device pumps oil to the bearing before the elevator trip starts (upon brake release signal) to establish proper lubrication film in advance. This preliminary lubrication action ensures that bearing surfaces are adequately coated before rotation begins, preventing dry start-up conditions while avoiding excessive temperature buildup during operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses periodic lubrication delivery triggered by brake release signals rather than continuous lubrication. Oil is pumped to the bearing at the start of each elevator trip and during operation, then drained back to the sump, creating a periodic lubrication cycle that maintains film formation without causing excessive temperature accumulation from continuous oil containment.

Inventive Principle:
Principle #19Periodic action

2Device complexity

If manual grease lubrication is used, then simplicity is maintained, but bearing life and efficiency worsen due to boundary lubrication

Engineering Contradiction:
Improvelubrication system complexityVSAvoidbearing life
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The lubrication device operates automatically upon receiving a brake release signal from the drive or controller, eliminating the need for manual grease gun operations. The system self-regulates by pumping oil to the bearing, allowing it to drain back to the sump, and maintaining proper oil levels without requiring technician intervention during normal operation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses a lubrication device with a pump to deliver oil hydraulically to the bearing. This hydraulic lubrication delivery mechanism replaces manual grease application with an automated fluid delivery system that provides consistent, controlled oil flow to achieve mixed film lubrication and extend bearing life.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 system optimizes bearing life, reduces maintenance frequency, and improves efficiency by ensuring consistent lubrication and cooling, facilitating extended high-speed operation while simplifying maintenance procedures.

Implementation Method 1

a lubrication device automatically transmitting oil to the bearings upon receipt of a brake release signal from the drive or the controller

Methodology Applied
Scientific EffectHydraulic lubrication: Lubrication

Implementation Method 2

the bearings are provided with a mixed film lubrication or an elastohydrodynamic lubrication to optimise bearing life expectation

Methodology Applied
Scientific EffectElastohydrodynamic lubrication: Lubrication

Implementation Method 3

the brake is hydraulically released and the elevator installation further comprises a pump and a solenoid valve whereby the pump is activated by the brake release signal

Methodology Applied
Scientific EffectHydraulic pressure release: Hydraulic Press

Data Source

PatentEP3704051B1An elevator installation and a method for lubricating bearings in the elevator installation
Publication Date: 2021.12.22 INVENTIO AG
  • EP3704051B1 patent drawingFigure 1
  • EP3704051B1 patent drawingFigure 2
  • EP3704051B1 patent drawingFigure 3A~3C

AI summary

An elevator installation (1) and a method for lubricating bearings (90) in an elevator hoist machine (10) such that during start-up and subsequent running of the elevator hoist machine (10) the bearings (90) are provided with a mixed film lubrication or an elastohydrodynamic lubrication to optimise bearing life expectation.