Abstract:
A camshaft assembly method may include locating a first lobe member of a camshaft assembly on a first shaft of the assembly. A locking pin may be inserted into a first radial bore in the first lobe member and a second radial bore of the first shaft. The locking pin may have an annular wall defining a pin bore extending from a first end of the locking pin to a second end of the locking pin. A deforming member may be forced into the pin bore to displace the annular wall in an outward radial direction and into a frictional engagement with the first radial bore. The forcing may include a deforming member entering the pin bore at the first end of the locking pin and exiting the pin bore at the second end of the locking pin.

Description:
FIELD 
     The present disclosure relates to engine camshaft assemblies. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Engines typically include a camshaft to actuate intake and exhaust valves. Some camshafts are concentric camshafts that provide for relative rotation between, for example, the intake and exhaust lobes. The intake lobes may be fixed to an outer shaft for rotation with the shaft and the exhaust lobes may be rotatably supported on the shaft. Alternatively, the exhaust lobes may be fixed to the outer shaft for rotation with the shaft and the intake lobes may be rotatably supported on the shaft. In any arrangement, the lobes that are rotatably supported on the outer shaft may be rotationally fixed to the inner shaft using a fastener. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not comprehensive of its full scope or all of its features. 
     A camshaft assembly method may include locating a first lobe member of a camshaft assembly on a first shaft of the assembly. A locking pin may be inserted into a first radial bore in the first lobe member and a second radial bore of the first shaft. The locking pin may have an annular wall defining a pin bore extending from a first end of the locking pin to a second end of the locking pin. A deforming member may be forced into the pin bore to displace the annular wall in an outward radial direction and into a frictional engagement with the first radial bore. The forcing may include a deforming member entering the pin bore at the first end of the locking pin and exiting the pin bore at the second end of the locking pin. 
     The locking pin may be hollow after the deforming member is forced through the pin bore. 
     A camshaft assembly may include a first shaft having a first radial bore, a first lobe member located on the first shaft and including a second radial bore aligned with the first radial bore, and a locking pin. The locking pin may be located within the first and second radial bores. The locking pin may include an annular body defining a generally hollow longitudinal bore extending from a first longitudinal end of the locking pin to a second longitudinal end of the locking pin. The first and second longitudinal ends may be frictionally engaged with the first lobe member. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. 
         FIG. 1  is a schematic illustration of an engine assembly according to the present disclosure; 
         FIG. 2  is a perspective view of the camshaft and cam phaser of  FIG. 1 ; 
         FIG. 3  is a perspective exploded view of the camshaft of  FIG. 1 ; 
         FIG. 4  is a first schematic illustration of a camshaft and a tool assembly according to the present disclosure; and 
         FIG. 5  is a second schematic illustration of the camshaft and tool according to the present disclosure. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Examples of the present disclosure will now be described more fully with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. 
     Referring now to  FIG. 1 , an exemplary engine assembly  10  is schematically illustrated. The engine assembly  10  may include an engine  12  including a plurality of cylinders  14  having pistons  16  disposed therein. The engine  12  may further include an intake valve  18 , an exhaust valve  20 , and intake and exhaust valve lift mechanisms  22 ,  24  for each cylinder  14 , as well as a camshaft  26  and a cam phaser  28 . 
     The intake valve lift mechanism  22  may include a pushrod  30  and a rocker arm  32 . The exhaust valve lift mechanism  24  may additionally include a pushrod  30  and a rocker arm  32 . Pushrods  30  may be engaged with the camshaft  26  to actuate the rocker arms  32  and selectively open the intake and exhaust valves  18 ,  20 . While the engine assembly  10  is illustrated as a pushrod engine, it is understood that the present disclosure is not limited to pushrod engines and may be applicable to a variety of other engine configurations as well, such as overhead cam engines. 
     With reference to  FIGS. 2-5 , the camshaft  26  may include first and second shafts  34 ,  36 , a first set of lobe members  38 ,  40 ,  42 ,  44 ,  46 , a second set of lobe members  48 ,  50 ,  52 ,  54 , and fasteners  56 . In the present example, the first set of lobe members  38 ,  40 ,  42 ,  44 ,  46  may form an intake lobe set and the second set of lobe members  48 ,  50 ,  52 ,  54  may form an exhaust lobe set. However, it is understood that alternate arrangements may be provided where the first set of lobe members  38 ,  40 ,  42 ,  44 ,  46  may form an exhaust lobe set and the second set of lobe members  48 ,  50 ,  52 ,  54  may form an intake lobe set. Further, each of the first and second sets of lobe members  38 ,  40 ,  42 ,  44 ,  46 ,  48 ,  50 ,  52 ,  54  are not limited to only intake or exhaust valves. For example, the first and second sets of lobe members  38 ,  40 ,  42 ,  44 ,  46 ,  48 ,  50 ,  52 ,  54  may each include an intake lobe and/or an exhaust lobe. The first shaft  34  may be fixed for rotation with a first phaser member  58  and the second shaft  36  may be fixed for rotation with a second phaser member  60 . The first and second phaser members  58 ,  60  may be rotatable relative to one another and relative to a rotationally driven member  62  of the phaser  28 . 
     The first shaft  34  may include an annular wall  64  defining an inner bore  66 . The second shaft  36  may be rotatably disposed within the inner bore  66  of the first shaft  34 . The first shaft  34  may include slots  68  (seen in  FIGS. 4 and 5 ) therethrough and the second shaft  36  may include apertures  70  that receive the fasteners  56  therein and couple the second set of lobe members  48 ,  50 ,  52 ,  54  for rotation with the second shaft  36 . The slots  68  may form radial bores through the first shaft  34  and the apertures  70  may form radial bores through the second shaft  36 . The slots  68  in the first shaft  34  may generally allow for a rotational travel of the fasteners  56  therein. 
     The first set of lobe members  38 ,  40 ,  42 ,  44 ,  46  may be fixed for rotation with the first shaft  34 . The engagement between the first set of lobe members  38 ,  40 ,  42 ,  44 ,  46  and the first shaft  34  may include a friction fit engagement. The second set of lobe members  48 ,  50 ,  52 ,  54  may be disposed between adjacent ones of the first set of lobe members  38 ,  40 ,  42 ,  44 ,  46 . The second set of lobe members  48 ,  50 ,  52 ,  54  may be rotatably disposed on the first shaft  34  and fixed for rotation with the second shaft  36  by the fasteners  56 . 
     As seen in  FIGS. 4 and 5 , the fasteners  56  may each include a locking pin  72 . The locking pin  72  may include an annular wall  74  defining a longitudinal bore  76  extending from a first end  78  of the locking pin  72  to a second end  80  of the locking pin  72 . By way of non-limiting example, the locking pin  72  may be in the form of a cylindrical member having a generally circular outer surface  82 . The longitudinal bore  76  may also have a generally circular cross-section. A deforming member  84  may be forced through the longitudinal bore  76  of the locking pin  72  to couple the locking pin  72  to the second set of lobe members  48 ,  50 ,  52 ,  54 . 
     A tool  86  may be used to force the deforming member  84  through the longitudinal bore  76  of the locking pin  72 . In the non-limiting example shown in  FIGS. 4 and 5 , the deforming member  84  may be generally spherical, having a diameter (D d ). The slots  68  in the first shaft  34  may have an axial width (D S1 ) and the apertures  70  may have a diameter (D S2 ). The axial width (D S1 ) may be greater than the diameter (D S2 ). The second set of lobe members  48 ,  50 ,  52 ,  54  may each include a radial bore  88  defining a diameter (D C ). The diameter (D C ) may be less than the axial width (D S1 ) and approximately equal to the diameter (D S2 ). 
     Referring to  FIG. 4 , the longitudinal bore  76  of the locking pin  72  may have an initial inner diameter (D Ii ) and an initial outer diameter (D Oi ). The initial inner diameter (D Ii ) may be less than the diameter (D d ) of the deforming member  84  and the initial outer diameter (D Oi ) may be less than the diameter (D C ) of the radial bore  88  in the lobe member  48 . The deforming member  84  may force the annular wall  74  of the locking pin  72  in an outward radial direction as the deforming member is forced through the longitudinal bore  76  in an axial direction (A). 
     More specifically, the relationship between the diameter (D d ) of the deforming member  84  and the initial inner diameter (D Ii ) of the locking pin  72  may provide the outward radial displacement of the annular wall  74  as the locking pin is advanced axially along the longitudinal bore  76 . After the deforming member  84  has been displaced through the longitudinal bore  76 , the locking pin  72  may have a final inner diameter (D If ) and a final outer diameter (D Of ), as seen in  FIG. 5 . 
     The final inner diameter (D If ) may be approximately equal to the diameter (D d ) of the deforming member  84  and the final outer diameter (D Of ) may be approximately equal to the diameter (D C ) of the bore  88  of the lobe member  48 . The locking pin  72  may therefore be frictionally engaged with and retained within the bore  88  of the lobe member  48 . Additionally, the final outer diameter (D Of ) of the locking pin  72  may be approximately equal to the diameter (D S2 ) of the aperture  70  in the second shaft  36 , fixing the locking pin  72  to the second shaft  36  as well. 
     After the deforming member  84  is forced through the longitudinal bore  76  of the locking pin  72 , the locking pin  72  may be fixed relative to the lobe member  48 . The locking pin  72  may remain hollow after being fixed to the lobe member  48 . Additionally, the first and second ends  78 ,  80  of the locking pin  72  may be swaged, or deformed in an outward radial direction, to further fix the locking pin  72  relative to the lobe member  48 . More specifically, the first and second ends  78 ,  80  may be displaced radially outward from the bore  88  of the lobe member  48  and into counter bores  90 ,  92 . 
     It is understood that the fastener  56  is shown in combination with the lobe member  48  in  FIGS. 4 and 5  for simplicity and the description applies equally to the remainder of the second set of lobe members  50 ,  52 ,  54 .