When the vehicle is running, the driving shaft rotates with the permanent magnet, and the magnetic field lines of the permanent magnet generate eddy currents on the aluminum bowl, and the eddy currents interact with the magnetic field of the permanent magnets to generate torque to overcome the elastic force of the disc spring so that the aluminum bowl rotates in the direction of the permanent magnets. Deflection, so the aluminum bowl turns an angle with the pointer. Since the strength of the eddy current is proportional to the speed of the vehicle, the rotation angle of the pointer is proportional to the speed of the vehicle, and the pointer indicates the corresponding speed on the dial. The speedometer gear assembly turns the speedometer cable, which in turn turns the speedometer mechanism itself. A small permanent magnet is attached to the speedometer cable interacting with a small aluminum cup (called the speedup attached to the needle shaft of the analog speedometer instrument). As the magnet spins near the cup, the changing magnetic field creates eddy currents in the cup, which themselves create another magnetic field. The effect of this is that the magnets apply torque on the cup, "drag" it, and thus "drag" the speedometer needle, causing it to rotate in the direction of rotation, with no mechanical connection between them.

Taizhou Yongchang Electric Vehicle Manufacturing Co., Ltd. not only has a speedometer but also motorcycle parts and accessories, welcome to check our official website.