Title:
Dual camshaft retaining plate
Kind Code:
A1


Abstract:
The engine has a pair of camshafts for actuating valves of the cylinders. Push rods extend from the camshafts to the valves in order to operate the engine. The ends of the camshafts are supported in the crankcase molding by bearings and a retaining plate supports and retains the camshafts in spaced relationship. The retaining plate has a pair of notches and each camshaft has a groove. The groove fits within the edge of the notch to insure that the camshafts are in proper alignment.



Inventors:
Trease, John M. (Melbourne, AU)
Application Number:
10/440124
Publication Date:
11/25/2004
Filing Date:
05/19/2003
Assignee:
TREASE JOHN M.
Primary Class:
International Classes:
F01L1/047; F01L1/14; F02B61/02; F02B75/22; F02F7/00; F02B75/18; (IPC1-7): F01L1/02; F01L1/18
View Patent Images:



Primary Examiner:
RIDDLE, KYLE M
Attorney, Agent or Firm:
Christopher J. McDonald, Esq. (Arlington, VA, US)
Claims:
1. An engine comprising: an engine block having at least one cylinder, a crankcase and a cam chest, the crankcase separated from the cam chest by a divider wall, at least one camshaft extending from the divider wall into the cam chest, and a retaining plate secured to said divider wall and retaining said at least one camshaft to maintain the at least one camshaft in position.

2. The engine of claim 1, wherein said retaining plate has a notch, said notch having an edge, and said at least one camshaft having a groove, wherein said edge of said notch fits into said groove to support said at least one camshaft.

3. The engine of claim 1, wherein the end of the at least one camshaft in supported in said engine block by a bearing.

4. The engine of claim 1, further comprising: two camshafts, each having a groove, and a pair of notches, each having an edge, wherein said edges of said notches fit into said grooves to support said camshafts.

5. An engine comprising: an engine block having a first and second cylinder and a cam chest, a front camshaft and rear camshaft extending through the cam chest for actuating cylinder valves, and a retaining plate in said cam chest, said retaining plate having a pair of notches, said notches formed in the edge of the retaining plate and engaging said camshafts.

6. The engine of claim 5, wherein said front and rear camshaft each having a groove extending about its entire circumference, wherein said edge of said notch fits into said groove in said front and rear camshaft to retain said camshaft.

7. An engine comprising: an engine block having at least one cylinder, a crankcase and a cam chest, the crankcase separated from the cam chest by a divider wall, at least one camshaft extending through the divider wall into the cam chest, the at least one camshaft having a first end and a second end, and a retaining plate having at least one notch, said at least one notch engaging the at least one camshaft between the first and second ends.

8. The engine of claim 7, wherein said at least one camshaft is a first and second camshaft and said at least one notch in a first and second notch.

9. The engine of claim 7, further comprising a groove in said at least one camshaft, said groove extending about the entire circumference of said at least one camshaft, said at least one notch engaging said at least one groove to retain the camshaft in position.

10. The engine of claim 7, wherein said at least one notch in formed in an edge of the retaining plate.

Description:

FIELD OF THE INVENTION

[0001] The invention relates to vee-twin engines having dual camshafts.

BACKGROUND OF THE INVENTION

[0002] A common type of motorcycle engine is the vee-twin engine having two cylinders arranged in a V-shape to accommodate pistons attached to a crankshaft. Many vee-twin engines have twin camshafts. Each camshaft controls the valves for the cylinder individually. The camshafts are driven by the crankshaft by a chain or gear arrangement. It is an object of the invention to provide a dual camshaft vee-twin engine having a plate to hold camshaft in a predetermined space relationship.

[0003] It is another object of the invention to provide a twin cam engine that is reliable over a long period of operating time.

[0004] It is another object of the invention to provide a dual camshaft engine that is reliable and inexpensive to manufacture.

[0005] It is yet another object of the invention to provide a dual camshaft engine that is easily maintained and repaired.

[0006] These and other objects of the invention will be apparent to one of ordinary skill in the art after review the invention disclosure.

SUMMARY OF THE INVENTION

[0007] The engine has a pair of camshafts for actuating valves of the cylinders. Push rods extend from the camshafts to the valves in order to operate the engine. The ends of the camshafts are supported in the crankcase molding by bearings and a retaining plate supports and retains the camshafts in spaced relationship. The retaining plate has a pair of notches and each camshaft has a groove. The groove fits within the edge of the notch to insure that the camshafts are in proper alignment.

BRIEF DESCRIPTION OF THE INVENTION

[0008] FIG. 1 is a perspective view of a vee-twin engine;

[0009] FIG. 2 is a plan view of the camshafts with gears of the driving mechanism incorporating the retaining plate;

[0010] FIG. 3 is a end view of the retaining plate with the camshafts removed for purposes of clarity; and

[0011] FIG. 4 is an end view of the engine without the retaining plate.

DETAILED DESCRIPTION OF THE INVENTION

[0012] Referring first to FIG. 1, a engine 10 having a cam chest 14 and two cylinders 19, 20 arranged in a V-configuration is depicted.

[0013] Tappet blocks 16, 17 are integrally formed with the engine and house cam followers. Push rods, not shown, extend through apertures 18 in the tappet blocks to actuate the inlet and exhaust valves of each cylinder. The cylinders have a 4½ inch bore and the tappet blocks are offset ⅜ inch to accommodate this bore. A camshaft is provided for each cylinder. The camshafts move the push rods to actuate the valves of each cylinder and are rotated, in turn, by the crankshaft of the engine housed within the cam chest 4.

[0014] Turning now to FIG. 2, a plan view of the camshafts can be seen. The engine has a crankshaft 22, connected to the pistons within each cylinder and driving the front camshaft 24 and rear camshaft 26. A primary gear 25 on the forward camshaft is driven by a gear (not shown) on the crankshaft 22. A secondary gear 27 on the front camshaft drives the rear camshaft by mating with a secondary gear 28. This drive gear arrangement is the subject of U.S. Pat. No. 6,543,401, herein incorporated by reference.

[0015] The ends of the front camshaft 24 and rear camshaft 26 are supported in the crankcase molding 40 by front camshaft bearing 34 and rear camshaft bearing 36, respectively.

[0016] FIG. 3 shows an end view of the mounting over the retaining plate and its relationship to the vee-twin engine. The crankcase molding defines an interior space through which the crankshaft 22, front camshaft 24 and rear camshaft (now shown) are situated. Retaining plate 50 is located between the crankshaft 22 and the camshafts, and has a pair of notches for accommodating the camshafts.

[0017] The retaining plate is held in position by locating dowels 53, 55 and retained in position by bolts 52, 54, 56. The retaining plate locates in a machine groove in the center of the camshaft. The setting of the camshafts within the notches of the retaining plate sets the correct end flow clearances for both camshafts.

[0018] FIG. 4 shows the relationship of the crankshaft 22 and camshafts 24, 26 before the installation of the retaining plate.

[0019] While the invention has been described with reference to a preferred embodiment, variations and modifications would be apparent to one of ordinary skill in the art without departing from the scope of the invention. The invention encompasses such variations and modifications. For instance, the retaining plate can be used in other engines besides a two cylinder, vee engine.