Gas supply pump for ship dual fuel engine

A gas supply pump for a ship dual fuel engine, comprising:

• a rotatable camshaft;
• a plurality of cam noses arranged at regular intervals along a lengthwise direction of the camshaft, wherein the cam noses are eccentric from a center of the camshaft;
• a cam roller in close contact with each cam nose;
• a drive shaft and a piston adjacent to each other on one side of the cam roller;
• and
• a liquefied gas compression device to compress and discharge liquefied gas by a linear reciprocating motion of the piston,
• wherein a cylinder side where the piston is embedded in the cylinder and reciprocates, and a rod side which is the other end of the piston, are respectively provided with a cylinder side sealing structure and a rod side sealing structure.