Rotary Encoder Bearing Fault Detection via Bushing Connection Status

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Solution Overview

Problem

Existing rotary encoders fail to reliably detect blocked or sluggish bearings, leading to increased driving torque and potential connection failure between the encoder shaft and the assembly shaft, risking damage and unsafe operation.

Innovation Solution

A rotary encoder with a bearing configuration that includes a shaft, bushing, rotor, and stator, equipped with an electrical circuit and detection device to determine the connection status between the stator and bushing, triggering an alarm or shutdown if a malfunction is detected, preventing extensive damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bearings are not monitored, then device complexity is reduced, but reliability deteriorates due to undetected bearing blockages leading to shaft connection failure

Engineering Contradiction:
Improvebearing operation reliabilityVSAvoiddetection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical monitoring systems with a simple electrical connection monitoring approach. The detection device monitors the electrical connection between the rotating bushing and the stationary housing through conductive elements, substituting mechanical bearing condition monitoring with electrical continuity detection, thereby improving reliability while maintaining simple device architecture

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

Solution Approach 2:

The bushing structure serves dual functions: it provides mechanical support for bearing rotation and simultaneously acts as a conductor for the detection circuit. The electrical connection is automatically maintained through the rotating contact elements embedded in the bushing, eliminating the need for separate monitoring mechanisms and simplifying the overall system

Inventive Principle:
Principle #25Self-service

2Reliability

If mechanical connection monitoring is implemented, then reliability improves, but device complexity increases due to additional mechanical components

Engineering Contradiction:
Improveconnection status detection reliabilityVSAvoidconnection monitoring mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the mechanical rotation function and electrical signal transmission function into a single integrated bushing structure. The conductive elements are embedded within the rotating bushing itself, combining mechanical support, rotation capability, and electrical conduction into one component, thereby achieving reliable connection monitoring without adding separate mechanical monitoring mechanisms

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bushing is designed as a multi-functional component that simultaneously provides mechanical bearing support, enables rotational motion, and serves as an electrical conductor for the detection circuit. This universal design eliminates the need for dedicated monitoring components and simplifies the overall device structure while maintaining detection reliability

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If bearing malfunction is not detected early, then loss of time is reduced, but harmful factors increase due to extended operation with blocked bearings causing shaft breakage

Engineering Contradiction:
Improvedamage to shaft and assemblyVSAvoiddetection time
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The detection device continuously monitors the electrical connection status before bearing malfunction leads to catastrophic failure. By detecting changes in electrical continuity caused by bearing blockage early in the malfunction process, the system enables preventive action before shaft connection failure occurs, reducing harmful effects despite requiring continuous monitoring

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4246097B1Rotary encoder and a method for determining malfunction of a rotary encoder
Publication Date: 2025.07.09 LEINE & LINDE
  • EP4246097B1 patent drawingFigure 1a~1b
  • EP4246097B1 patent drawingFigure 2a~2b
  • EP4246097B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a rotary encoder (200) comprising a shaft (210) having a bearing configuration (220), said bearing configuration (220) being internally connected to an axial bushing (230) arranged in a housing (280), the bearing configuration (220) being configured to allow rotation of the shaft (210) relative to said housing (280), a rotor (250) being attached to said shaft (210), the rotary encoder also comprises a stator (260), the rotary encoder (200) further comprising: an arrangement (245; 247; 205; 241; 242) configured to determine malfunction of the bearing configuration (220), said arrangement comprising a detection device (205) configured to determine whether a connection device (245, 247) is operably connected between a fixed portion (260; 280) of said rotary encoder (200) and said bushing (230), and to output the status of the connection to a control arrangement (201), whereby if there is no connection, said detection device (205) is configured to determine a rotation of said bushing (230) associated with malfunction of the bearing configuration (220). The invention relates also to a computer program product comprising program code (P) for a computer (201; 205; 500) for implementing a method according to the invention. The invention relates also to a method for determining malfunction of a rotary encoder (200).