Yamaha XP500 Service Manual page 20

GEN
FEATURES
INFO
EAS00878
ABS component functions
• Wheel sensors and sensor rotors
Wheel sensors 1 detect the wheel rotation
speed and transmit the wheel rotation signal to
2
the ECU (ABS).
Each wheel sensor is composed of a perma-
nent magnet and a coil. The wheel sensors are
1
installed in the sensor housing for each wheel.
2
1
Sensor rotors 2 are installed inside the front
and rear wheel hubs and rotate with the
wheels. Each sensor rotor has 40 serrations
that face the sensor housing. As the distance
changes between the top and bottom of the
serrations with the rotation of the wheels,
inductive electromotive force is generated in
the wheel sensors. Wheel rotation speed is
detected based on the frequency of this alter-
nating voltage.
3 At high speed
4 At low speed
5 Wheel sensor
6 Sensor rotor
EAS00879
• Hydraulic unit
The hydraulic unit 1 is composed of a hydrau-
lic control valve (solenoid valve, flow control
valve), a buffer chamber, and a hydraulic
1
pump for each brake and an ABS motor. The
hydraulic unit adjusts the front and rear wheel
brake fluid pressure to control the wheel rota-
tion speed according to signals transmitted
from the ECU (ABS).
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