Radial Magnetic Sensor for Brushless Motor Angle Detection

The patent transitions from axial magnetic field reading to radial magnetic field reading. The magnets are arranged radially on the rotor, and the Hall sensors are positioned to detect the radial component of the magnetic flux. This dimensional change allows the sensor to be installed away from the front end of the shaft, enabling straightforward electric brake installation without brackets or additional complexity.

The patent changes the reading direction from axial to radial. The radial magnetic flux density is measured by Hall sensors positioned radially outward from the rotor magnets. Since radial displacement caused by gear axial movements does not affect the radial measurement as significantly as axial displacement affects axial measurement, this dimensional change provides stable and precise readings even with axial clearances present in the system.

The patent changes the measurement parameter from axial magnetic flux density to radial magnetic flux density. The radial component of the magnetic field is inherently stronger and more stable. During braking, when heat dilation occurs and axial clearances change, the radial measurement remains stable because the radial distance from the rotor magnets to the stator sensors is not significantly affected by axial thermal expansion, thus maintaining measurement precision.

The patent changes the output signal type from digital to analog. By using radial magnetic field reading with Hall sensors, the system naturally produces analog sinusoidal waveforms that represent the motor angle and speed. These analog signals are directly compatible with traditional analog control systems and power electronics, eliminating the need for digital-to-analog conversion and ensuring broad system compatibility while maintaining full automation capability.