Riser tensioner having oil collecting means

Abstract

A riser tensioner that includes an oil collecting means and tensions a riser extending to the seabed from a drilling ship which drills for submarine resources. The riser tensioner further includes a piston rod partially inserted into each of the cylinders and reciprocating within the cylinder, a piston seal disposed between a head of the piston rod and a wall of the cylinder to provide fluid sealing, an oil collection passage extending from the head of the piston rod to an outside of the cylinder through the piston rod to allow oil leaking into the cylinder through the piston seal to be discharged from the cylinder to the outside of the cylinder through the oil collection passage, and an oil leakage detection sensor which detects oil leakage positioned on the head of the piston rod.

1 . A riser tensioner disposed under a drilling ship to tension a riser used for drilling operation of submarine resources and including a plurality of cylinders into which oil is supplied, the riser tensioner further comprising:
 a piston rod partially inserted into each of the cylinders and reciprocating within the cylinder;   a piston seal disposed between a head of the piston rod and a wall of the cylinder to provide fluid sealing therebetween; an oil collection passage extending from the head of the piston rod to an outside of the cylinder through the piston rod to allow oil leaking into the cylinder through the piston seal to be discharged from the cylinder to the outside of the cylinder through the oil collection passage; and   a first oil leakage detection sensor configured to detect oil leakage in the piston seal and located on the head of the piston rod.   
     
     
         2 . The riser tensioner of  claim 1 , further comprising: a collection tank connected to the oil collection passage and configured to store collected oil. 
     
     
         3 . The riser tensioner of  claim 2 , wherein the collection tank is provided with an a second oil leakage detection sensor configured to detect oil leakage.