Low-Speed Bearing Damage Diagnosis via Reference Element Position Monitoring

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Solution Overview

Problem

Existing methods for diagnosing damage in slowly rotating roller bearings, such as those using acceleration sensors and encoders, are ineffective at early detection due to vibration loss at lower speeds and delayed deviation in shaft position, respectively.

Innovation Solution

A device comprising a frame with a shaft and a reference element mounted on the shaft bearing, allowing the reference element to rotate freely relative to both the shaft and frame, which is coupled to a position transmitter for early damage signaling, and optionally an alternative drive to induce vibrations detectable by a vibration transmitter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If acceleration sensors are used to monitor bearing vibrations, then the system can detect bearing damage, but at low speeds the vibrations are lost in the measured frequency spectrum and damage cannot be recognized at an early stage

Engineering Contradiction:

Improvedamage detection capabilityVSAvoidrotational speed

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The patent introduces a reference element as an intermediary component that rotates with the shaft and triggers the sensor at specific angular positions. This mediator converts the low-speed rotational information into high-frequency electrical signals that can be clearly detected above the noise floor, solving the problem of vibration loss at low speeds

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct mechanical vibration measurement with an electrical triggering system. Instead of relying on mechanical vibrations that become indistinguishable at low speeds, the system uses a reference element with triggering elements that generate electrical signals, substituting mechanical detection with electrical detection

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If encoders are used to scan shaft position, then the system can monitor shaft position continuously, but the trajectory deviation from circular path only occurs in advanced damage cases

Engineering Contradiction:

Improveposition measurement accuracyVSAvoidearly damage detection reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The reference element is pre-configured with triggering elements at specific angular positions that correspond to potential damage locations. This preliminary arrangement allows the system to detect damage at its earliest stages by triggering when the reference element passes these predetermined positions, rather than waiting for significant trajectory deviations to occur

Inventive Principle:

Principle #10Preliminary action

3Reliability

If a reference element is introduced to rotate freely between shaft and frame, then early damage detection is enabled, but the device complexity increases

Engineering Contradiction:

Improvedamage diagnosis reliabilityVSAvoiddevice structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The reference element serves multiple functions: it rotates with the shaft, provides a reference for position measurement, triggers the sensor at specific angles, and enables damage detection. This multi-functionality reduces the need for separate components and justifies the added complexity by consolidating several functions into one element

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enables early detection of bearing damage through position monitoring and vibration analysis, improving the reliability of damage diagnosis in slowly rotating roller bearings.

Implementation Method 1

a position transmitter, which is arranged between the reference element and the frame

Methodology Applied

Scientific EffectPosition sensing:

Implementation Method 2

a vibration transmitter which is arranged on the frame in the area of the bearing of the reference element and the shaft bearing

Methodology Applied

Scientific EffectVibration detection:

Data Source

PatentEP3225967B1A device for error diagnosis of low-speed bearings

Publication Date: 2018.12.05 SKODA AUTO AS

Figure 1~2
Figure 3~4

AI summary

A device for damage diagnosis of slow-rotating rolling bearings is formed by a frame (5) in which the shaft (1) is mounted and which has shaft bearings (2) arranged in the reference element (3), which is rotatably mounted in the bearings (4) relative to the frame (5). The reference element (3) is connected to a position sensor (6) connected to the frame (5), by means of which damage to the bearings (2, 4) is signaled at an early stage. In an alternative embodiment, the reference element (3) is coupled to an alternative drive (7) with a predefined higher rotational speed than the rotational speed of the shaft (1). By measuring the vibrations triggered at the frame (5) near the bearings (2, 4), the defined amplitude of the frequency spectrum is determined, which indicates the state of damage to the bearings (2, 4).