Sensor Assembly for Fluid Rotation Machine Shaft Detection

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Solution Overview

Problem

Existing rotary fluid machines face challenges in accurately detecting shaft rotation due to complex sensor installation requirements and potential interference from hydraulic fluid, leading to increased operational complexity and susceptibility to errors.

Innovation Solution

A sensor arrangement is designed with a receiving area sealed within the machine's housing, allowing hydraulic fluid to lubricate contact surfaces and reducing torque requirements, while the sensor housing is securely fastened to the front cover without needing an opening for moving elements, enabling precise rotation detection with minimal torsion and easy maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the sensor is positioned to be less obtrusive, then the sensor arrangement is improved, but the sensor cannot directly detect the shaft's rotation and requires multiple contact points with play

Engineering Contradiction:
Improvesensor arrangementVSAvoidshaft rotation detection
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The sensor is nested within the receiving area that is sealed within the housing, allowing the sensor to be positioned optimally for detection while being protected from hydraulic fluid interference. The sensor assembly is integrated into the housing structure rather than being externally mounted.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

A non-magnetic, fluid-permeable membrane or window is introduced as an intermediary between the hydraulic fluid environment and the sensor. This allows hydraulic fluid to reach the sensor for lubrication while preventing fluid leakage and magnetic field interference with the sensor's detection function.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the sensor assembly requires an opening for moving elements, then the sensor can detect rotation, but additional seals are needed which increase complexity and wear

Engineering Contradiction:
Improveshaft rotation detectionVSAvoidsensor installation
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensor assembly is nested within the sealed receiving area of the housing, eliminating the need for separate openings and seals. The sensor is positioned inside the housing where it can detect shaft rotation directly without requiring additional sealing components.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The receiving area is merged with the housing structure, combining the sensor mounting function with the housing's existing sealed cavity. This integration eliminates the need for separate sensor openings and associated seals, reducing complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If the sensor is located outside the receiving area, then the receiver can be positioned outside the housing, but the sensor cannot directly detect rotation without additional transmission elements

Engineering Contradiction:
Improvesensor arrangementVSAvoidtransmission elements
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The sensor is nested within the receiving area that is sealed within the housing, allowing the sensor to be positioned optimally for detection while being protected from hydraulic fluid interference. The sensor assembly is integrated into the housing structure rather than being externally mounted.

Inventive Principle:
Principle #7Nested doll (Nesting)

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

This configuration enhances operational reliability, reduces wear, and simplifies sensor installation and maintenance by eliminating the need for additional seals and minimizing torsional stress, allowing for accurate and efficient detection of shaft rotation with low-friction interactions and adaptable sensor components.

Implementation Method 1

hydraulic fluid can penetrate the receiving area and simultaneously lubricate the contact surfaces between the sensor and the housing or other components

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

A transmitter and receiver are provided, wherein the transmitter is arranged in the receiving area and the receiver is arranged outside the receiving area

Methodology Applied
Scientific EffectMagnetic field interaction: Magnetic Field

Data Source

PatentEP2369172B1Fluid rotation machine with a sensor assembly
Publication Date: 2020.02.19 DANFOSS POWER SOLUTIONS APS
  • EP2369172B1 patent drawingFigure 1~2
  • EP2369172B1 patent drawingFigure 3a~3c
  • EP2369172B1 patent drawingFigure 4a~4b

AI summary

Fluid rotary machine (1) comprising a housing (2), a shaft (3) extending from the housing (2), and a sensor arrangement (10) comprising a sensor (12) operatively connected to the shaft (3), and a receiver (15). The sensor arrangement (10) has a receiving area in which the sensor (12) is arranged, the receiving area being in fluid communication with the interior of the housing (2) and sealed to the outside, and the receiver (15) being arranged outside the housing (2) and the receiving area.