a knife sharpening system mountable in a small vehicle is disclosed . the knife sharpening system includes a grinding device including a motor , and an abrasive member directly connected to the motor without using a reduction device , to reduce loss of power transmitted from a battery to the abrasive member , and a water - proof device for preventing scattering of water and dust caused by rapid rotation of the abrasive member . the abrasive member can rotate using small force in accordance with direct connection of the abrasive member to the motor . even when the abrasive member rotates at high speed , scattering of water or dust is prevented in accordance with direct connection of the abrasive member to the motor . accordingly , the abrasive member can be driven using a battery of a small vehicle .