Speed sensor for traction motors of rail vehicles

Abstract

The invention discloses a speed sensor for traction motors of railway vehicles. The speed sensor comprises a speed measuring probe and a transmission cable, wherein the speed measuring probe comprisesa probe shell, a printed circuit board, a Hall sensitive component and two precise two-way operational amplifiers; the Hall sensitive component is fixedly connected at one end of the printed circuitboard; the transmission cable is fixedly connected at the other end of the printed circuit board; and the two precise two-way operational amplifiers are respectively arranged on the front and back sides of the printed circuit board. The speed sensor disclosed by the invention has the advantages that on the premise that the volume of the sensor is constant, the precise two-way operational amplifiers are arranged on the front and back sides of the printed circuit board to ensure that two square wave signals are output by one Hall sensitive element and four signals can be generated via the printed circuit board, so that the requirements of traction systems and braking systems of the rail vehicles are met at the same time.

Description

technical field [0001] The invention belongs to the field of sensors, in particular to a speed sensor capable of outputting four-way signals for a traction motor of a rail vehicle. Background technique [0002] On a rail vehicle, the control of the vehicle power system largely depends on the accuracy and reliability of the speed signal it collects, and the speed signal collected includes the current speed value and the variation of the speed. In locomotive traction control, wheel slip protection, train control, and car door control, the collection of speed signals is involved, which is generally completed by many speed sensors. [0003] The most commonly used type of speed sensor is the Hall-type dual-channel speed sensor. Its inductive element is two magnetically biased Hall-sensitive elements (the traditional two Hall elements each generate only one square wave signal, and a The signal can be processed by the dual operational amplifier. Note: The dual operational amplifie...

AI Technical Summary

Problems solved by technology

Due to the presence of two magnetically biased Hall sensor elements in the probe, the diameter of the speed measuring probe is large and cannot meet the customer's drawing requirements

[0004] In addition, due to the small space between the motor end cover and the bearing end cover of some rail vehicles, or in order to reduce costs, the speed sensor is required to output 4 signals to be transmitted to the traction system and the braking system respectively (each system requires 2 phases The square wave signal with a difference of 90°, the two square waves of different systems correspond to 180°), the traditional single speed sensor can only output two signals and cannot meet the application requirements (in the vehicle control system, the traction system and the braking system cannot Use the same two-way square wave signal as the basis for system control, otherwise it will cause system confusion and cannot work normally)

[0005] At the same time, due to the harsh operating environment of rail vehicles, there are various electromagnetic interferences in the speed loop. In the electromagnetic interference, the surge voltage / current with large energy will cause the greatest harm to the speed sensor. When the energy of the surge voltage / current exceeds the speed sensor When the power of the protection element is exceeded, it will directly destroy the protection element and damage the speed sensor

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