Electric oil pump

An electric oil pump, comprising:

• a base portion, which can be assembled on an oil drum and has a fluid passage;
• a pump portion, disposed on the base portion, capable of executing an oil pumping operation to allow oil from the oil drum to flow through the fluid passage in the base portion, wherein the pump portion is detachable from and attachable to the base portion;
• a power supply, configured to provide an electric power required for the pumping operation of the pump portion;
• a power switch, disposed on the pump portion;
• a mechanical switch, disposed on the base portion and having a pressing member, wherein, when the pressing member is not pressed, the mechanical switch is in a conductive state, and when the pressing member is pressed, the mechanical switch is in a non-conductive state;
• and
• a pressure trigger, located between the mechanical switch and the fluid passage, capable of pressing the pressing member when the pressure in the fluid passage is above an upper threshold and releasing the pressing of the pressing member when the pressure in the fluid passage is below a lower threshold,
• wherein when the pump portion is attached to the base portion, the mechanical switch on the base portion is electrically connected to the power switch on the pump portion,
• wherein when the pump portion is detached from the base portion, the mechanical switch on the base portion is disconnected from the power switch on the pump portion, and
• wherein the pressure trigger comprises a casing and a movable element, the casing having a channel and a chamber that communicate with each other, the movable element having a bottom end located within the chamber of the casing, and a top end extending out of the casing through the channel and contacting the pressing member of the mechanical switch, wherein the movable element is normally in a non-triggered position where the pressing member is not pressed, and is movable from the non-triggered position to a triggered position under the pressure in the fluid passage, and presses the pressing member at the triggered position.