Engine

Abstract

An engine includes: a cylinder head; a cam housing fastened to the cylinder head; a camshaft rotatably supported by the cam housing and supplied with lubricating oil; and a head cover fastened to the cam housing, wherein the cam housing includes a side wall extending along the camshaft, and an inner side surface of the side wall includes a recessed region recessed downward in a gravity direction.

What is claimed is: 
     
         1 . An engine comprising:
 a cylinder head;   a cam housing fastened to the cylinder head;   a camshaft rotatably supported by the cam housing and supplied with lubricating oil; and   a head cover fastened to the cam housing,   wherein   the cam housing includes a side wall extending along the camshaft, and   an inner side surface of the side wall includes a recessed region recessed downward in a gravity direction.   
     
     
         2 . The engine of  claim 1 , wherein
 the cylinder head includes a first seal surface that sandwiches a first seal member in cooperation with the side wall,   the side wall includes a second seal surface that sandwiches a second seal member in cooperation with the head cover, and   the recessed region is provided at a position closer to the first seal surface than the second seal surface.   
     
     
         3 . The engine of  claim 2 , wherein
 the inner side surface of the side wall includes an upper region continuous from the recessed region to an upper side in the gravity direction, and   the upper region is located outside the cam housing with respect to a line connecting an inner edge of the first seal surface and an inner edge of the second seal surface when viewed in a cross section perpendicular to a direction in which the camshaft extends.   
     
     
         4 . The engine of  claim 3 , wherein
 the inner side surface of the side wall is smoothly continuous from the upper region to the recessed region when viewed in the cross section perpendicular to the direction in which the camshaft extends.   
     
     
         5 . The engine of  claim 1 , wherein the recessed region extends along the camshaft. 
     
     
         6 . The engine of  claim 1 , wherein the side wall includes a rib partially projecting inside the cam housing. 
     
     
         7 . The engine of  claim 6 , wherein
 the side wall includes:
 an intake side wall located on an intake side; and 
 an exhaust side wall located on an exhaust side, and 
   the rib is provided on the exhaust side wall.