| 摘要 |
A speed sensor has a static part and a dynamic part arranged concentrically inside the static part. The static part has two permanent magnets and the dynamic part has two further permanent magnets. The magnet is oriented reversely to the further magnets. The magnets are tuned to each other so that gravity on the dynamic part is counteracted by the magnetic force on the dynamic part. As a result, the weight of the dynamic part need not be carried by springs and the dynamic part can move freely so that the full stroke can be used for measuring accelerations and the natural frequency is low. The static part further includes a measuring coil for measuring the displacement of the dynamic part and for the radial positioning of the dynamic part this part is connected to the static part by means of leaf springs. |
