Integrated Rotor Speed Sensor in Electrical Machine Cover

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Solution Overview

Problem

Conventional electrical machines require significant installation space and are costly due to the use of add-on encoders for detecting rotational positions and speeds, which also face challenges with high-speed operation and maintenance.

Innovation Solution

Integrating a rotary encoder, comprising a printed circuit board with a second sensor element, into the cover element of the electrical machine, allowing for space-saving and cost-effective detection of rotational positions and speeds, while avoiding the need for external encoders and simplifying installation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If add-on encoders are used for detecting rotational positions and speeds, then detection precision is improved, but installation space and cost increase

Engineering Contradiction:
Improverotational position and speed detection precisionVSAvoidaxial installation space
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The patent merges the encoder functionality with the cover element by integrating the printed circuit board containing the second sensor element directly into the cover element structure. This combination eliminates the need for separate add-on encoders, reducing axial installation space while maintaining detection precision through the integrated sensor arrangement.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The printed circuit board with the second sensor element is nested within the cover element structure, specifically arranged in the receiving space that is partially delimited by the cover element. This nesting approach allows the detection device to be housed within the existing machine housing volume without requiring additional external space.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Measurement precision

If add-on encoders are used for detecting rotational positions and speeds, then detection precision is improved, but manufacturing cost increases

Engineering Contradiction:
Improverotational position and speed detection precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent combines the encoder functionality with the cover element, eliminating the need for separate add-on encoder components. This integration reduces the total part count and assembly complexity, leading to lower manufacturing costs while maintaining the required detection precision through the integrated sensor system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cover element is designed to serve multiple functions: it provides mechanical protection, defines the receiving space, and integrates the detection device through the printed circuit board with the second sensor element. This multi-functionality eliminates the need for separate encoder components, reducing manufacturing cost while maintaining detection capabilities.

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

3Difficulty of detecting and measuring

If add-on encoders are used for detecting rotational positions and speeds, then detection capability is improved, but device complexity increases

Engineering Contradiction:
Improvedetection capabilityVSAvoidassembly and maintenance complexity
Core Design Contradiction:
Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The patent merges the detection device with the cover element, creating an integrated assembly that simplifies the overall system structure. This integration reduces the number of separate components that need to be assembled and maintained, thereby reducing device complexity while preserving full detection capability through the coordinated sensor elements.

Inventive Principle:
Principle #5Merging (Combining)

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 solution reduces the axial installation space, lowers costs, and simplifies the assembly and maintenance of electrical machines by integrating the detection device within the cover element, enabling precise speed and position detection without the need for external encoders.

Implementation Method 1

the detection device comprises at least one first sensor element which is arranged in the receiving space and which can rotate with the rotor and is connected to the rotor in a rotationally fixed manner, for example. In addition, the detection device comprises a printed circuit board arranged in the receiving space with at least one second sensor element, by means of which the rotational positions or the rotational speed of the rotor can be detected in cooperation with the first sensor element

Methodology Applied
Scientific EffectMagnetic field interaction: Magnetic Field

Data Source

PatentEP3583681B1Electrical machine
Publication Date: 2020.12.30 SIEMENS AG
  • EP3583681B1 patent drawingFigure 1~2
  • EP3583681B1 patent drawingFigure 3~4
  • EP3583681B1 patent drawingFigure 5~6

AI summary

The invention relates to an electrical machine (10), comprising a stator (12), a rotor (16) that is rotatable about an axis of rotation (16) relative to the stator (12), a machine housing (22), in which the stator (12) and the rotor (14) are in each case at least predominantly received, a cover element (26) that is formed separately from the machine housing (22) and is retained on the machine housing (22), a receiving space (28), which is in each case partially delimited by the machine housing (22) and by the cover element (26), and a detection device (34) configured for detecting rotational positions and/or a rotational speed of the rotor (14), which detection device has at least one first sensor element (36) arranged in the receiving space (28) and co-rotatable with the rotor (14) and at least one circuit board (42) arranged in the receiving space (28) having at least one second sensor element (44), by means of which in co-operation with the first sensor element (36) the rotational positions and/or the rotational speed of the rotor (14) can be detected, the circuit board (42) being retained on the cover element (26).