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Toothed Signal Rotor

A toothed signal rotor is a crucial component of an Anti-lock Braking System (ABS). It rotates with the hub, drive axle, axle, or ring gear and works in conjunction with wheel speed sensors to generate electrical impulses for the ABS electronic control unit (ECU).


  • Material: Usually made of metal, designed to be durable and withstand the harsh conditions of automotive environments.
  • Teeth: The rotor has evenly spaced teeth along its circumference. These teeth pass by a wheel speed sensor as the rotor rotates.


  • Impulse Generation: As the toothed rotor spins, its teeth interrupt the magnetic field of the wheel speed sensor, generating a series of electrical impulses.
  • Signal Transmission: These impulses are sent to the ABS ECU, which monitors the frequency and pattern of the signals.


  • ABS Systems: The primary use of the toothed signal rotor is in the ABS of vehicles. It helps the system determine wheel speed and detect rapid deceleration, which could indicate wheel lock-up.
  • Traction Control Systems: It is also used in traction control systems to monitor and manage wheel spin during acceleration.

Operation in ABS:

  1. Rotation: The rotor rotates with the wheel or axle.
  2. Signal Generation: As the teeth pass by the wheel speed sensor, they create a fluctuating magnetic field, producing electrical impulses.
  3. Data Processing: The ABS ECU receives these impulses and counts them to calculate the wheel speed.
  4. Monitoring: The ECU continuously monitors the wheel speed signals. If it detects rapid deceleration, indicating potential wheel lock-up, it modulates the brake pressure to prevent skidding and maintain traction.


  • Precision: Provides accurate and real-time data on wheel speed, which is critical for the effective operation of ABS and traction control systems.
  • Reliability: Robust design ensures consistent performance under various driving conditions and over the vehicle’s lifespan.
  • Safety: Enhances vehicle safety by helping prevent wheel lock-up and maintaining control during braking.


  • Wear and Tear: Subject to wear over time, which can affect signal accuracy. Regular maintenance and inspection are necessary.
  • Sensitivity: The system’s effectiveness can be compromised by dirt, debris, or damage to the rotor or sensor.

The toothed signal rotor is an integral part of modern vehicle safety systems, playing a crucial role in maintaining control and stability during braking and acceleration. Its ability to generate precise and reliable signals ensures that the ABS and related systems can function effectively, contributing to overall vehicle safety.

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