Contactless Switching Device for Geared Motor Position Sensing
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Solution Overview
Problem
Existing switching devices for electric motors lack a contactless, absolute position-measuring capability and independent switching functionality, particularly for geared motors, which limits their ability to control motor current based on precise positional data and ensures safety positions during power outages.
Innovation Solution
A contactless absolute position-measuring device, an evaluation unit, and an output unit are integrated within a single housing on a rotating component of the motor, allowing for indirect or direct switching of the motor current based on position signals, with power self-sufficiency through magnetic induction and redundant signal outputs for enhanced reliability and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a mechanical or electronic switch is used for switching the motor, then the switching function is provided, but contactless position measurement and absolute position sensing are not available
Solution Approach 1:
The patent combines the position-measuring device, evaluation unit, and output unit into a single integrated switching device housing. This merging of previously separate components (position sensor, control logic, and switching output) into one unit provides contactless absolute position measurement while maintaining a compact structure that does not significantly increase overall device complexity.
Solution Approach 2:
The patent replaces mechanical contact-based switching with a contactless switching mechanism controlled by the evaluation unit. The output unit provides switching signals based on position data from the position-measuring device without mechanical contact, eliminating wear and improving reliability while enabling precise position measurement.
2Reliability
If external supply power is switched off, then energy saving is achieved, but the motor cannot be positioned in safety positions
Solution Approach 1:
The position-measuring device continuously monitors and stores position information even when external supply power is switched off. The evaluation unit retains the ability to determine safety positions based on stored position data, enabling the motor to be positioned safely when power is restored without requiring continuous power consumption for positioning maintenance.
Solution Approach 2:
The integrated switching device serves itself by using the position-measuring device to continuously track position information and the evaluation unit to process this data for safety positioning. The device maintains position awareness and safety positioning capability through its own internal resources without requiring external power during idle periods.
3Device complexity
If the switching device is integrated on the rotating component, then compact design is achieved, but the device must be power self-sufficient
Solution Approach 1:
The integrated switching device on the rotating component serves multiple functions: the position-measuring device provides position data, the evaluation unit processes this data and generates control signals, and the output unit provides switching outputs. This multi-functional integration reduces the need for separate power supply systems while maintaining power self-sufficiency through shared power management resources.
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
Enables precise control of electric motors with contactless position sensing, continued operation during power outages, and reduced wear through optimized movement control, meeting safety standards like SIL 1, and supports various power supply types and communication interfaces.
Implementation Method 1
The position-measuring device is preferably constructed in such a way that it senses a change in the position of the component on the basis of a change in a magnetic field
Implementation Method 2
The position-measuring device advantageously senses a single, in particular, complete, rotation and/or a multiplicity of rotations of the component which is driven in rotation
Data Source
AI summary
A geared motor is provided, including an electric motor, a transmission, a drive shaft and a switching device arranged on the drive shaft. The switching device includes a single housing that is distinct and separate from an electric motor housing and a transmission housing. The switching device also includes a contactless, absolute position-measuring device and an evaluation unit, each provided within the single housing, a gear wheel coupled to the drive shaft, and an output unit. The switching device is coupled to the position-measuring device by a pinion, which rotates about the same rotational axis as the drive shaft.