Locking device and locking system

A locking device (100) comprising:

• a housing (110);
• a plunger (120) inserted into the housing (110), movable in a longitudinal direction relative to the housing (110) and rotatable around the longitudinal direction to transit between a locking position and an unlocking position, wherein when the plunger (120) is in the unlocking position, the plunger (120) is in a first rotating position and a first axial position, when the plunger (120) is in the locking position, the plunger (120) is in a second rotational position different from the first rotational position and a second axial position different from the first axial position, a guide groove (125) is arranged on an outer peripheral surface of the plunger (120), the guide groove (125) including a guide groove engage segment (125c);
• a rotor (160) accommodated in the housing (110) and rotatable around a rotor rotation axis (169) relative to the plunger (120) between an engaged position and a disengaged position, wherein when the plunger (120) is in the locking position, the rotor (160) is rotatable to the engaged position to prevent the plunger (120) from moving;
• and
• a motor (140) accommodated in the housing (110) and configured to drive the rotor (160) to rotate;
• a guide (181) located near an open end of the housing (110), and the guide (181) extends from an inner surface of the housing (110) to abut the guide groove (125) and move relative to the guide groove (125), causing the plunger (120) to be forced to rotate to the first rotational position when the plunger (120) moves to the first axial position, and be forced to rotate to the second rotational position when the plunger (120) moves to the second axial position;
• and
• the guide groove engage segment (125c) is set so that when the plunger (120) is in the locking position and the rotor (160) is in the engaged position, a rotor edge (162) of the rotor (160) is engaged with the guide groove engage segment (125c) to prevent a longitudinal movement of the plunger (120), and the guide groove (125) is set to avoid mutual interaction between the plunger (120) and the rotor (160) when the rotor (160) is in the disengaged position.