Roller cutter with improved sealing

Abstract

A roller cutter intended to be used at a drill head for rotary boring of the front of earth and rock formations, the roller cutter having a centre line and being provided with a hub having rows of crushing members. At least one crushing member has its longitudinal axis at an angle relative to a normal to the centre line. The hub is rotatable in relation to a shaft having shaft spigots. The roller cutter is provided with at least one seal retainer arranged at an axial end of the hub in order to hold a sealing means in position. The hub includes at least one circumferential recess positioned axially inward relative to a radially inward projecting flange in the hub.

1 . A roller cutter intended to be used at a drill head for rotary boring of the front of earth and rock formations, said roller cutter comprising:
 a centre line and a hub provided with rows of crushing members, at least one crushing member having a longitudinal axis at an angle relative to a normal to the centre line, said hub being rotatable in relation to a shaft having shaft spigots; and at least one seal retainer arranged at an axial end of the hub to hold a sealing means in position, wherein the hub includes at least one circumferential recess positioned axially inward relative to a radially inward projecting flange in the hub.   
     
     
         2 . The roller cutter according to  claim 1 , wherein one side surface of the flange constitutes a boundary of the at least one recess. 
     
     
         3 . The roller cutter according to  claim 1 , wherein the seal retainer has a maximum axial extension and the flange and the at least one recess are positioned radially outward from said seal retainer and are axially entirely contained within said axial extension. 
     
     
         4 . The roller cutter according to  claim 1 , further comprising an O-ring positioned in the at least one recess. 
     
     
         5 . The roller cutter according to  claim 1 , wherein the at least one seal retainer includes a radially outward directed projecting part disposed at a position forming a seal retainer's axial and radial outermost end. 
     
     
         6 . The roller cutter according to  claim 5 , wherein the projecting part is a ring. 
     
     
         7 . The roller cutter according to  claim 6 , wherein the ring is metallurgically bonded to the seal retainer. 
     
     
         8 . The roller cutter according to  claim 1 , wherein the hub includes at least one circumferential indent disposed radially outward from and adjacent to the projecting part on the seal retainer. 
     
     
         9 . The roller cutter according to  claim 1 , wherein at least one seal retainer has a groove at its axially outermost end.