To-be-detected shaft rotation speed detecting device and system

The invention discloses a to-be-detected shaft rotation speed detecting device and system. The device includes a signal fluted disc and a connection support mounted on an end face of a to-be-detected shaft. A transmission shaft arranged coaxially with the to-be-detected shaft is formed on the connection support. The signal fluted disc is mounted on the transmission shaft. The device also includes a sensor fixing support mounted on the transmission shaft through a bearing. Besides, a rotation speed sensor used for detecting rotation speed signals of the signal fluted disc is mounted on the sensor fixing support. A sensing end of the rotation speed sensor is opposite to the teeth part of the signal fluted disc. By mounting the sensor fixing support and the signal fluted disc in a coaxial manner, synchronous vibration of the sensor fixing support and the signal fluted disc in a testing process can be guaranteed and interference due to background vibration can be avoided, so that accuracy of detection results can be improved. By designing the signal fluted disc, the bearing, the sensor fixing support and the connection support in an assembling type, skillful design is realized and mounting and adjusting are facilitated. Single-process mounting is implemented; the universality is high; and use convenience and reliability are achieved.