Rotary Encoder Sensor Unit with Magnetic Segment Counter
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Solution Overview
Problem
Existing rotary encoder systems are bulky and require a large number of precise components to accurately measure rotary angles beyond 360° and count a practically unlimited number of revolutions while detecting rotation direction, which is not efficient in terms of complexity, cost, and space usage.
Innovation Solution
A sensor unit with a segment counter that generates counting signals for angular positions within a full revolution, using a magnetic exciter arrangement with permanent magnets and a pulse or Wiegand wire, and an electronic circuit that stores count values in a non-volatile memory, allowing operation independent of external energy supply by harnessing kinetic energy from the drive shaft, combined with a singleturn for enhanced resolution and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a revolution counter uses optical scanning sensors or multi-field Hall probes to measure rotary angles beyond 360°, then measurement precision is improved, but device complexity and structural size increase
Solution Approach 1:
The patent divides the measurement task into two independent parts: a segment counter that handles full revolutions (360°) using simple magnetic sensors, and a singleturn that handles fractional revolutions within one revolution. This segmentation allows each component to be simpler and less expensive while collectively achieving high measurement precision for angles beyond 360°.
Solution Approach 2:
The patent transitions from two-dimensional optical scanning or Hall probe systems to a one-dimensional magnetic flux-based segment counter. By using magnetic flux conductors and simple magnetic sensors instead of complex optical or multi-field Hall probe systems, the patent reduces device complexity while maintaining the ability to measure rotary angles beyond 360°.
2Reliability
If a rotary encoder system uses external power supply and batteries to ensure continuous operation, then reliability is improved, but device complexity and cost increase
Solution Approach 1:
The patent implements a self-powered system where the rotating drive shaft itself generates the electrical energy needed to operate the sensor unit through electromagnetic induction. The changing magnetic flux generated by the rotating permanent magnets induces electrical pulses in the sensor coil, which provides power to the electronic circuit without requiring external power supplies or batteries. This self-service approach ensures reliable operation while reducing device complexity.
Solution Approach 2:
The patent replaces the mechanical/electrical power supply system (batteries, external power sources) with an electromagnetic generation system. The mechanical rotation of the drive shaft is converted into electrical energy through electromagnetic induction, eliminating the need for separate power supply components and reducing overall device complexity.
3Ease of manufacture
If a sensor unit uses magnetic exciter arrangement with permanent magnets and pulse wire, then ease of manufacture is improved, but measurement precision for angular positions may be compromised
Solution Approach 1:
The patent changes the operating parameters by using a magnetic exciter arrangement with permanent magnets and a pulse wire instead of complex optical or multi-field Hall probe systems. This magnetic field-based approach simplifies manufacturing while maintaining sufficient measurement precision for the intended application, as the magnetic flux changes provide clear, distinct signals for angular position detection.
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
The solution enables precise measurement of rotary angles in segments less than 360°, counts an unlimited number of revolutions with direction detection, and stores count values efficiently, reducing structural size and complexity while maintaining high accuracy and resolution, making it suitable for various applications without the need for external power.
Implementation Method 1
the stored energy is then liberated abruptly so that an electrical pulse is inductively generated therefrom
Implementation Method 2
the exciter arrangement is formed for example by a permanent magnet, the magnetic field of which represents the physical parameter exciting the stationary sensor
Data Source
AI summary
There is described a sensor unit (3) for a rotary encoder which serves for detecting the rotary movements of a drive shaft (1) in both directions and which has a single-stage transmission with an input gear (15) which is arranged concentrically with respect to and is non-rotatably connected to the drive shaft (1). The sensor unit includes an absolute segment counter which serves for counting the angle segments through which the drive shaft passes within each 360° rotation and has the following components: a magnetic segment counter exciter arrangement non-rotatably mounted on the second gear (16) of the transmission, that engages into the input gear, a stationary segment counter sensor arrangement which includes a Wiegand or pulse wire (28) with wound-on induction coil (29) and which delivers electrical pulses whenever the magnetic segment counter exciter arrangement passes through predetermined angular positions, and an electronic circuit (32) which counts said electrical pulses, stores the respectively acquired count value and calculates therefrom the instantaneous angular position of the drive shaft having regard to the transmission ratio of the transmission.