Valve clearance adjustment mechanism
First Claim
1. An internal combustion engine, comprising:
- an engine housing;
a valve train disposed within said engine housing, said valve train including at least one valve moveable between closed and open positions, and at least one cam lobe mounted for rotation;
a shaft supported by said engine housing and moveable between first and second adjustment positions;
an adjustment member mounted to said shaft, said adjustment member having an eccentric portion;
at least one valve actuator pivotally mounted upon said eccentric portion of said adjustment member, said valve actuator having a first portion in engagement with said cam lobe and a second portion located adjacent said valve to define a clearance space therebetween when said valve is in said closed position, wherein when said shaft is in said first adjustment position, said adjustment member may be rotated to move said valve actuator and vary said clearance space, and when said shaft is in said second adjustment position, the position of said adjustment member is fixed.
8 Assignments
0 Petitions
Accused Products
Abstract
A valve clearance adjustment mechanism for use in small internal combustion engines such as, for example, side valve engines and overhead valve engines, which generally include intake and exhaust valves actuated by lifters pivotally mounted within the engine housing, which in turn are actuated by cam lobes driven in timed rotation with the crank shaft. An adjustment member is provided for mounting each lifter to a shaft, wherein the adjustment member is eccentric relative to the shaft, such that rotation of the adjustment member modifies the position of the lifter and in turn modifies the valve clearance between the lifter and the valve. After the valve clearance has been properly set, the adjustment member is fixed in position.
2 Citations
22 Claims
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1. An internal combustion engine, comprising:
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an engine housing;
a valve train disposed within said engine housing, said valve train including at least one valve moveable between closed and open positions, and at least one cam lobe mounted for rotation;
a shaft supported by said engine housing and moveable between first and second adjustment positions;
an adjustment member mounted to said shaft, said adjustment member having an eccentric portion;
at least one valve actuator pivotally mounted upon said eccentric portion of said adjustment member, said valve actuator having a first portion in engagement with said cam lobe and a second portion located adjacent said valve to define a clearance space therebetween when said valve is in said closed position, wherein when said shaft is in said first adjustment position, said adjustment member may be rotated to move said valve actuator and vary said clearance space, and when said shaft is in said second adjustment position, the position of said adjustment member is fixed. - View Dependent Claims (2, 3, 4, 5)
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6. An internal combustion engine, comprising:
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an engine housing including therein at least one rotatable cam lobe, at least one valve, and at least one valve actuator periodically engaging said cam lobe to actuate said valve, wherein a clearance space is defined between said valve actuator and said valve when said lifter is not engaged by said cam lobe; and
a mechanism for adjusting said clearance space, comprising;
a shaft having a head portion, said shaft adjustably securable to said engine housing between first and second positions; and
an adjustment member mounted to said shaft, said adjustment member having an eccentric portion upon which said valve actuator is pivotally mounted, wherein when said shaft is in said first adjustment position, said adjustment member may be rotated upon said shaft to move said valve actuator and vary said clearance space, and when said shaft is in said second adjustment position, said adjustment member is captured between said shaft head portion and said engine housing to fix the position of said adjustment member. - View Dependent Claims (7, 8, 9, 10)
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11. In combination:
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an internal combustion engine including a cam having a lobe periodically engaging a valve actuator to actuate a valve within a housing of said engine, wherein a clearance space exists between said valve actuator and said valve when said valve actuator is out of engagement with said lobe; and
a valve clearance adjustment mechanism, comprising;
an eccentric adjustment member upon which said valve actuator is pivotably mounted, said adjustment member adjustable to vary the location of said valve actuator and said clearance space; and
a shaft upon which said adjustment member is rotatably mounted, said shaft engageable with said engine housing to fix the rotational position of said adjustment member and thereby set said clearance space. - View Dependent Claims (12, 13, 14, 15)
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16. An internal combustion engine comprising:
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a cam having a lobe periodically engaging a valve actuator to actuate a valve within a housing of said engine, wherein a clearance space exists between said valve actuator and said valve when said valve actuator is out of engagement with said lobe; and
a valve clearance adjustment mechanism, comprising;
a shaft supported by said engine housing;
an eccentric adjustment member rotatably mounted upon said shaft and adjustably supporting said valve actuator, said adjustment member including at least one stop portion engageable with said engine housing to limit the rotation of said adjustment member such that corresponding adjustment of said valve actuator is substantially confined to movement of said valve actuator in a direction parallel to said valve. - View Dependent Claims (17, 18, 19)
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20. A method of adjusting the clearance between a valve and a valve actuator which is pivotally mounted upon a shaft within the housing of an internal combustion engine, comprising the steps of:
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adjusting an eccentric adjustment member disposed between the shaft and the valve actuator to move the valve actuator in one of a direction closer or further away from the valve to provide a desired clearance between the valve actuator and the valve; and
rotating the shaft to engage the shaft with the engine housing and capturing the adjustment member in a fixed position between the shaft and the engine housing to fix the clearance between the valve and the valve actuator. - View Dependent Claims (21, 22)
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Specification