Angle Measuring System With Integrated Rotary Transformer

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Solution Overview

Problem

Existing angle measuring systems face challenges in achieving a compact and economically producible modular design that enables contactless transmission of electrical signals and power, particularly in applications where precise angular position measurement and rotational movement are required, such as in machining centers and measuring machines.

Innovation Solution

The angle measuring system comprises a rotatable shaft and housing with a rotary transformer that includes a primary winding for power transmission and a circuit board with an antenna for signal transmission, featuring a geometrically aligned fastening system for secure attachment and a rigid-flexible circuit board for efficient signal processing, allowing for contactless transmission of electrical signals and power between rotating machine parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a rotary transformer with optical marking and photodiode cell is used for angle measurement, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveangular position measurement precisionVSAvoidsystem structural complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the angle measuring device and rotary transformer into a single integrated modular unit. The housing of the angle measuring device serves as the housing for the rotary transformer, and both components share common mounting features and fastening mechanisms. This merging eliminates the need for separate mounting operations and reduces the overall number of components while maintaining both measurement precision and contactless power transmission capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The modular design creates a universal assembly that can be applied to various machining centers and measuring machines. The standardized housing with recesses and fastening devices allows the same angle measuring system to be mounted on different machine types without modification. The system simultaneously provides angle measurement, contactless power transmission, and signal transmission functions through integrated components.

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

2Ease of operation

If slip rings are used for electrical transmission between stationary and rotating parts, then ease of operation is improved, but reliability deteriorates due to contact wear

Engineering Contradiction:
Improveelectrical transmission easeVSAvoidelectrical transmission reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces the mechanical contact system of slip rings with a contactless electromagnetic induction system using a rotary transformer. The primary winding on the stationary part and secondary winding on the rotating part transmit electrical energy and signals through magnetic coupling without physical contact. This substitution eliminates wear and contact resistance issues while maintaining ease of electrical transmission between stationary and rotating components.

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

3Productivity

If a compact modular design is implemented, then productivity is improved through easier assembly, but manufacturing precision requirements increase

Engineering Contradiction:
Improveassembly efficiencyVSAvoidfastening alignment precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent incorporates pre-formed recesses in the housing and corresponding fastening devices with geometric patterns during the manufacturing process. These pre-prepared features ensure that when the modular assembly is put together, the fastening devices automatically align with the recesses without requiring complex alignment procedures. The geometric pattern of fastening devices is designed to match the recess locations, enabling straightforward congruent alignment.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The housing features asymmetric recesses positioned at specific locations that correspond to the geometric pattern of fastening devices on the rotary transformer. This asymmetric arrangement with specifically positioned recesses provides unique alignment references that guide the assembly process, ensuring that the modular components are correctly positioned relative to each other during installation.

Inventive Principle:
Principle #4Asymmetry

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 enables precise angular position measurement and efficient wireless power and signal transmission, enhancing the system's compactness and economic production while ensuring reliable operation in machine tools and measuring machines.

Implementation Method 1

The primary part (2.1) has a primary winding (2.11) for contactless transmission of electrical power

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the circuit board has an antenna for transmitting the electrical signals from the primary part to the secondary part

Methodology Applied
Scientific EffectElectromagnetic radiation:

Data Source

PatentEP4047325B1Angle measuring system
Publication Date: 2024.05.22 DR JOHANNES HEIDENHAIN GMBH
  • EP4047325B1 patent drawingFigure 1~2
  • EP4047325B1 patent drawingFigure 3~4
  • EP4047325B1 patent drawingFigure 5

AI summary

The invention relates to an angle measuring system comprising an angle measuring device (1) and a rotary transmitter (2). The angle measuring device (1) comprises a shaft (1.11) and a housing (1.21), wherein the shaft (1.11) is rotatably arranged relative to the housing (1.21) about an axis (A), and the housing (1.21) has recesses (1.211). The rotary transmitter (2) has a primary part (2.1) with a primary winding (2.11) for transmitting electrical power. The primary part (2.1) has fastening devices (2.12) arranged according to a pattern that allows the fastening devices (2.12) to be aligned with the recesses (1.211) of the housing (1.21). Accordingly, screws (1.23) can be inserted through both the recesses (1.211) and the fastening devices (2.12) to fasten the angle measuring device (1) together with the rotary transmitter (2) to a first machine part. In addition, the primary part (2.1) has a pocket (2.13) in which a printed circuit board (2.14) is arranged, wherein the pocket (2.13) is arranged axially offset to the primary winding (2.11) radially outside the housing (1.21) and partially surrounds the housing (1.21) in a segmented manner. (Figure 7).