Valve timing control apparatus

Abstract

A boss portion of a vane rotor includes a tapered outer wall surface, which is tilted relative to an axis of the boss portion. A housing member includes a tapered inner wall surface that contacts the tapered outer wall surface. A seal member is provided at one axial end surface of the vane rotor on one axial side of the vane rotor, toward which the vane rotor urges the housing member by an interaction between the tapered outer wall surface of the supporting portion and the tapered inner wall surface of the housing member.

1 . A valve timing control apparatus for an internal combustion engine, comprising:
 a follower shaft that drives at least one of an intake valve and an exhaust valve of the internal combustion engine to open and close the at least one of the intake valve and the exhaust valve;   a drive force transmitting member that transmits a drive force from a drive shaft of the internal combustion engine to the follower shaft;   a gear that is engaged with the drive force transmitting member and receives the drive force from the drive force transmitting member to rotate synchronously with the drive shaft;   a housing member that has an outer peripheral wall, along which the gear extends annularly to rotate integrally with the housing member;   a vane rotor that includes a supporting portion and a vane, wherein the vane is rotated together with the supporting portion, which is in turn rotated together with the follower shaft, and the vane is received in a receiving chamber formed in the housing member and is rotatable relative to the housing member only within a predetermined angular range; and   a seal member that is placed at one axial end surface of the vane rotor and is held between the vane rotor and the housing member, wherein:   the supporting portion of the vane rotor includes a tapered outer wall surface, which is tilted relative to an axis of the supporting portion;   the housing member includes a tapered inner wall surface that contacts the tapered outer wall surface of the supporting portion; and   the seal member is provided at the one axial end surface of the vane rotor on one axial side of the vane rotor, toward which the vane rotor urges the housing member by an interaction between the tapered outer wall surface of the supporting portion and the tapered inner wall surface of the housing member.   
   
   
       2 . The valve timing control apparatus according to  claim 1 , wherein the seal member limits leakage of hydraulic fluid from a hydraulic chamber, which is defined in the receiving chamber and receives the hydraulic fluid to exert a hydraulic pressure to drive the vane in a circumferential direction. 
   
   
       3 . The valve timing control apparatus according to  claim 1 , wherein the gear is provided to the outer peripheral wall of the housing member at an axial location between the one axial end surface of the vane rotor and the other axial end surface of the vane rotor. 
   
   
       4 . The valve timing control apparatus according to  claim 1 , wherein the gear is provided to the outer peripheral wall of the housing member such that an axial extent of the gear does not overlap with an axial extent of the vane rotor. 
   
   
       5 . The valve timing control apparatus according to  claim 1 , further comprising a limiting member, which is received in a hole of the vane in an axially reciprocally movable manner to limit relative rotation of the vane rotor relative to the housing member, wherein the limiting member is fittable into an engaging portion provided in an inner wall of the housing member on the other axial side that is opposite from the one axial side, toward which the vane rotor urges the housing member. 
   
   
       6 . The valve timing control apparatus according to  claim 1 , wherein:
 the seal member is configured into a generally annular disk body; and   an outer diameter of the seal member is larger than an outer diameter of the vane rotor.   
   
   
       7 . The valve timing control apparatus according to  claim 1 , wherein a tilt angle of the tapered outer wall surface relative to the axis of the supporting portion is within a range of 3 to 10 degrees. 
   
   
       8 . The valve timing control apparatus according to  claim 1 , wherein:
 the supporting portion is located on an axial side of the follower shaft; and   the tapered outer wall surface of the supporting portion is tapered in an axial direction away from the follower shaft.   
   
   
       9 . The valve timing control apparatus according to  claim 1 , wherein:
 the supporting portion is located on an axial side of the follower shaft; and   the tapered outer wall surface of the supporting portion is tapered in an axial direction toward the follower shaft.   
   
   
       10 . The valve timing control apparatus according to  claim 1 , wherein:
 the tapered outer wall surface of the supporting portion extends continuously generally from the one axial end surface of the vane rotor to the other axial end surface of the vane rotor; and   an axial extent of the tapered inner wall surface of the housing member, which is measured in a direction parallel to the axis of the supporting portion, is larger than that of the tapered outer wall surface of the supporting portion.   
   
   
       11 . The valve timing control apparatus according to  claim 1 , wherein:
 a clearance is axially provided between the one axial end surface of the vane rotor and the housing member; and   the seal member slidably contacts the one axial end surface of the vane rotor in the clearance.