Bearing Wireless Sensor Noise Suppression Magnetic Shield
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Solution Overview
Problem
Existing wireless sensor-equipped bearings using electromagnetic induction for power generation face challenges in suppressing noise on circuit units and obtaining necessary electric power at low-speed rotation or initial stages of use.
Innovation Solution
A wireless sensor-equipped bearing design that includes a coil and magnet configuration with a magnetic shield to suppress noise, and a retainer and seal structure that allows for efficient power generation by electromagnetic induction, enabling operation even at low-speed rotation or initial stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If electromagnetic induction is used for power generation in wireless sensor-equipped bearings, then power generation capability is improved, but noise occurs on circuit units
Solution Approach 1:
The bearing is divided into functionally independent modules: the magnetic shield is positioned between the magnet and coil to segment the electromagnetic field generation zone from the circuit unit zone, allowing power generation to occur in one segment while protecting the circuit segment from electromagnetic noise interference
Solution Approach 2:
A magnetic shield serves as an intermediary component placed between the electromagnetic induction elements (magnet and coil) and the circuit unit. This intermediary blocks or redirects magnetic flux, preventing direct coupling between the power generation field and the circuit, thereby eliminating noise while preserving power generation capability
2Device complexity
If thermoelectric power generation (Seebeck element) is used, then power generation mechanism is simplified, but necessary power cannot be obtained at low-speed rotation or initial stage
Solution Approach 1:
The patent changes the operating parameters of electromagnetic induction by using alternating polarity magnets arranged in the circumferential direction, which creates stronger and more frequent magnetic flux variations during rotation. This parameter optimization enables effective power generation even at low rotation speeds, overcoming the limitation of thermoelectric methods that require significant temperature differences
3Device complexity
If vibration power generation (electret element) is used, then power generation mechanism is simplified, but necessary power cannot be obtained at low-speed rotation or initial stage
Solution Approach 1:
The electromagnetic induction system is designed with optimized magnetic flux density distribution through alternating polarity magnet arrangement and proper coil positioning. This creates sufficient induced voltage even at low rotation speeds, whereas vibration-based methods require significant mechanical vibration amplitude that is unavailable during initial low-speed operation
4Power
If annular magnet and conductor are added for electromagnetic induction, then power generation capability is improved, but device complexity increases
Solution Approach 1:
The magnet and coil components are designed to serve dual functions: they generate electromagnetic induction for power generation while simultaneously creating a controlled magnetic field that can be shielded from the circuit unit. The magnetic shield itself becomes a multi-functional element, serving both as field containment and as noise protection for the circuit
Solution Approach 2:
The patent merges the power generation function with the sealing function by integrating the coil and magnet system into the seal structure. This combination eliminates the need for separate power generation components, reducing overall device complexity while maintaining power generation capability
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 design effectively suppresses noise and ensures reliable power generation and sensor functionality at low-speed rotations or initial stages, improving power generation efficiency and reducing power consumption.
Implementation Method 1
a power supply circuit configured to supply to a power-supplied unit an electric current generated in the coil by electromagnetic induction due to relative rotation between the magnet and the coil
Implementation Method 2
a magnetic shield configured to magnetically shield at least the wireless circuit of the circuit unit from the magnet
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
There is provided a wireless sensor-equipped bearing. A plurality of magnets (5) are fixed between pockets of a retainer (4) formed of an annular body such that an N pole and an S pole of the magnets neighbor in a circumferential direction of the annular body. A coil (8), a circuit unit and an antenna are fixed to a surface (71a) of a first seal (7), the surface (71a) being opposed to the magnets (5). A sensor is disposed on any one of an inner ring (1), an outer ring (2) and the first seal (7).