Patent Application
20160084118
This invention relates to a valve operating system for an internal combustion engine in which two valves are simultaneously operated by one valve bridge.
In some valve operating systems for large Diesel engines, two valves are simultaneously operated by one valve bridge pushable downward by a rocker arm. As an engine cam shaft rotates, a push rod is selectively actuated by cams located on the cam shaft. The push rods, in turn, direct an upward force on one end of a rocker arm to cause the rocker arm to pivot about a pivot point. As the rocker arm pivots, its opposite end generates a downward force to selectively open an engine valve. Thus, the rocker arm translates the motion of the cam shaft into the opening of the engine valves. Since the timing of the opening of the intake and exhaust valves is important to proper operation of an internal combustion engine, anything that interferes with the timing will detrimentally effect engine performance.
In more detail, typical diesel valve operating systems include rocker arms which are integral, one-piece components having a first end, a second end, and an intermediate portion for pivotally mounting the rocker arm. The first end of the rocker arm has a push rod engagement portion that engages with an upper end of a push rod. Typically, the push rod engagement portion is a downwardly facing recess which receives the upper end of the push rod. The second end of the rocker arm includes a contact surface that engages a valve bridge, which in turn applies downward movement to the respective valve stems, thereby opening the engine valves.
Prior art designs for engaging a valve bridge are undesirable in that they are susceptible to scrubbing. Since the rocker arm makes a circular motion with its rocker shaft as its center, it pushes downward the valve bridge at the top of the bridge while slightly scrubbing the surface in the transverse direction, which in turn leads to irregularity in the timing relationship between the cam shaft and the valves. Irregularity in the timing relationship increases engine noise and decreases engine performance and efficiency.
Accordingly, there is a need to provide an improved valve bridge that minimizes or eliminates scrubbing, thereby increasing power and efficiency of the engine.
In accordance with the invention, a valve operation system is provided which utilizes a unique valve bridge adapted to fit current and future combustion engines in which two valves are simultaneously operated by an valve bridge. The operation system is easy to install, lightweight, and provides significant increases in gas mileage and power output.
Generally speaking the valve operating system for the internal combustion engine in which two valves are simultaneously operated includes two valves each having a valve stem end; a rocker arm having a forward end, the forward end having a contact surface; and a valve bridge that operates the two valves.
The valve bridge includes first and second ends each having an internal sleeve adapted to receive the respective stem end of each valve, a central reservoir, and a roller operably recessed within the central reservoir which is in contact with the contact surface of the rocker arm during actuation. The presence of the roller during operation mitigates the transverse force created by the rotation of the rocker arm upon the valve bridge, thereby increasing efficiency and minimizing wear on the engine.
In a version of the invention, the valve bridge central reservoir is adapted to retain and provide oil to the roller during operation of the valves. More particular, the central reservoir may include a concave surface which partially extends radially about the curved surface of the roller forming a space therebetween for oil to collect and to apply to the roller during operation, thereby further reducing friction and increasing efficiency. Optionally, the first and second ends of the valve bridge each may further comprise an oil passage connecting the upper surface with each respective internal sleeve allowing oil to pass freely from the upper surface to the lower surface of the valve bridge.
In other version, it may be beneficial to incorporate one or more exterior recessed curved surface in order to reduce the overall weight of the valve operation system, which further increases efficiency and power output.
Still other benefits and advantages of the invention will become apparent to those skilled in the art to which it pertains upon a reading and understanding of the following detailed specification.
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description and accompanying figures where:
Referring now to the figures wherein the showings are for purposes of illustrating a preferred version of the invention only and not for purposes of limiting the same, the present invention is a valve operating system for an internal combustion engine in which two valves are simultaneously operated by a unique valve bridge system.
The following detailed description is of the best currently contemplated modes of carrying out exemplary versions of the invention. The description is not to be taken in the limiting sense, but is made merely for the purpose illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
Various inventive features are described below that can each be used independently of one another or in combination with other features.
With reference to the drawings, and in particular to
Conventionally, as known in the diesel engine industry, a diesel engine typically has two or more cylinders, each cylinder having two or more exhaust valves. For example, a Duramax diesel engine manufactured by General Motors has eight cylinders, each having two exhaust valves per cylinder, with the pair of exhaust valves operated by one valve bridge operating system.
In the version shown, the valve operating system 10 generally comprises two valves 12 each having a valve stem 14, a rocker arm 16, and a valve bridge 18.
The rocker arm 16 is generally a one-piece components having a rear end 22, a forward end 24, and an intermediate portion 26 for pivotally mounting the rocker arm 16 about the rocker shaft 28. The rear end 22 of the rocker arm 16 has a push rod engagement portion 30 that engages with an upper end of a push rod 32. The push rod engagement portion 30 is a downwardly facing recess which receives the upper end of the push rod 32. The forward end 24 of the rocker arm 16 includes a contact surface 27 or optionally a wear pad 29 as known in the automotive industry that engages the valve bridge 18 when actuated. In the version 10, the contact surface 27 is generally flat, however, can be manufactured with a curved or angled surface as an alternative configuration for contacting the valve bridge 18. It will be known, that a wear pad 29 does not need to be utilized.
As illustrated in detail in
Moreover, the central reservoir 42 is adapted to retain and provide oil to the roller during operation of the valves 12. The central reservoir 42 includes a concave surface 48 which partially extends radially about the curved surface 50 of the roller 40 forming a space 52 therebetween for oil to collect and to apply to the roller 40 during operation of the valve operating system 10.
The first end portion 34 and the second end portion 36 each have an internal sleeve 54 and 56 adapted to receive the respective valve stem end 15 of each valve stem 14. The sleeves 54 and 56 are generally cylindrical in shape and are laterally spaced apart in order to bridge the gap between the valve stem ends 15. The sleeves 54 and 56 are of sufficient depth to securely seat over the valve stem ends 15 of the valve stems 14 as shown in
In the illustrated version, the first end portion 34 and the second end portion 36 each have an oil passage 58 and 60 connecting the upper surface 46 with each respective internal sleeves 54 and 56. This enables oil to freely pass between the upper surface 46 and the lower surface 62 and around the engaged valve stem ends 15 during operation of the valve operation system 10.
As best illustrated by
Referring to
When a transverse force acts upon the roller 40 pushing the valve bridge downward, the roller 40 rolls on the contact surface 27 or a wear pad 29 while pushing downward. Since the roller 40 does not transversely scrub the surface of the contact surface 27, but rolls while pushing downward, no transverse force is delivered to the valve bridge 18. Accordingly, guiding mechanisms for resisting the transverse force are not necessary as is different from the prior art.
The valve operation system utilizing the novel valve bridge has produced excellent results in fuels efficiency and horsepower output. Tests utilizing the system in conjunction with a General Motors Duramax diesel engine have produced an increase in approximately 15 HP detected at the rear wheel. Testing has also have shown an increase in fuel efficiency in as much as 1.3 miles per gallon when applied to a General Motors Duramax diesel engine.
The present invention can be made in any manner and of any material chosen with sound engineering judgment. Preferably, materials will be strong, lightweight, long lasting, economic, and ergonomic. Portions of the system, including the valve bridge 18, may be fabricated from any number of suitable materials, such as, without limitation, titanium, steel and aluminum. Likewise, the portions of the system may be finished in any number of ways, including anodizing, painting, milling or left in their respective unfinished states.
Although preferred embodiments of the invention have been described in considerable detail, other versions and embodiments of the invention are certainly possible. Therefore, the present invention should not be limited to the described embodiments herein.
All features disclosed in this specification including any claims, abstract, and drawings may be replaced by alternative features serving the same, equivalent or similar purpose unless expressly stated otherwise.
