Hydraulic Shock Detection via Pump Speed and Motor Frequency

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Solution Overview

Problem

Existing methods for detecting hydraulic shock in fluid systems are unreliable, prone to false positives, and require sensors in direct contact with the fluid, which are at risk of damage and complicate setup and maintenance.

Innovation Solution

An apparatus and method that monitor pump speed and motor frequency variations to detect hydraulic shock events, using magnetic field sensors and vibration sensors to identify sudden fluctuations consistent with hydraulic shock, without requiring direct fluid contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pressure sensors are used to detect hydraulic shock events, then detection accuracy is improved, but sensor reliability deteriorates due to direct fluid contact and risk of damage

Engineering Contradiction:
Improvedetection accuracyVSAvoidsensor reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent uses pump speed and motor frequency as intermediary parameters to indirectly detect hydraulic shock events. Instead of placing sensors in direct contact with the fluid, the system monitors the pump motor's operational parameters (speed and frequency) which change in response to hydraulic shock. This intermediary approach allows detection of shock events while keeping sensors isolated from the harmful fluid environment, thus maintaining both detection accuracy and sensor reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If pressure sensors are installed in the fluid system, then hydraulic shock detection capability is improved, but device complexity and maintenance difficulty increase

Engineering Contradiction:
Improvedetection capabilityVSAvoidsetup complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent leverages the pump motor's existing operational parameters (speed and frequency) as self-service indicators of hydraulic shock events. The motor's own performance characteristics serve as the detection mechanism, eliminating the need for separate pressure sensing systems. This approach reduces device complexity by utilizing already-present system parameters rather than adding external sensing infrastructure.

Inventive Principle:
Principle #25Self-service

3Loss of time

If sensors in direct fluid contact are used, then real-time hydraulic shock detection is achieved, but ease of operation deteriorates due to maintenance requirements and installation complexity

Engineering Contradiction:
Improveresponse timeVSAvoidmaintenance ease
Core Design Contradiction:
Loss of timeVSEase of operation

Solution Approach 1:

By using pump speed and motor frequency as intermediary measurement parameters, the system achieves real-time detection of hydraulic shock events without requiring physical sensors in the fluid path. These electrical and mechanical parameters can be monitored continuously through the existing motor control system, providing immediate response capability while eliminating the maintenance burden associated with fluid-contact sensors.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4433712B1Method and apparatus for detecting hydraulic shock
Publication Date: 2025.12.31 GRUNDFOS HLDG
  • EP4433712B1 patent drawingFigure 1~2
  • EP4433712B1 patent drawingFigure 3
  • EP4433712B1 patent drawingFigure 4~5

AI summary

Disclosed herein are embodiments of an apparatus for detecting hydraulic shock events in a fluid system, the fluid system comprising a pump assembly, the pump assembly comprising a pump, in particular a centrifugal pump, and a pump motor, the apparatus comprising means for monitoring a pump speed of the pump and/or for monitoring a motor frequency; and a processing unit configured to detect a variation in the monitored pump speed and/or motor frequency; and detect a hydraulic shock event from the detected variation in the monitored pump speed and/or motor frequency.