TECHNICAL FIELD
The disclosure relates to an indexed hydraulic roller lifter and associated systems and methods. Namely, the disclosed embodiments relate to a hydraulic roller lifter having an indexed portion to reduce friction on the cam head and prevent rotation of the lifter.
BACKGROUND
Internal combustion engines (“ICE”) have been around for over 100 years. The ongoing need to improve performance in push rod engines is crucial if we are to reduce the effect of greenhouse gas emissions. Hydraulic roller lifters as opposed to hydraulic flat lifters can reduce friction between the cam and the lifter thus increasing engine efficiency. This roller lifter must be indexed for the rollers to roll on the cam.
Most roller lifters are paired to accomplish this, however, to replace hydraulic flat lifters with roller lifters, pairing is not always an option in existing engine blocks. Newer engine designs—some experimental—have the lifter and rod assembly inside the engine, exposing them to coolant. There is need for an indexed lifter/rod assembly. This assembly will index the roller lifter with respect to the cam and protect the oil lubricant from being contaminated with the water based coolant.
BRIEF SUMMARY
One general aspect includes a hydraulic roller lifter, including a lifter body having first and second ends; at least one indexing portion set into the first end; and a wheel disposed at the second end. Implementations may include one or more of the following aspects. The hydraulic roller lifter further including a roller lifter tube. The hydraulic roller lifter where the roller lifter tube defines a lumen. The hydraulic roller lifter where the lumen defines at least one index tab. The hydraulic roller lifter where the roller lifter tube is press-fit into an engine block. The hydraulic roller lifter where the at least one index tab is constructed and arranged to prevent rotational movement of the lifter body. The hydraulic roller lifter where the at least one index tab is constructed and arranged to prevent rotational movement of the lifter body at the indexing portion. The hydraulic roller lifter further including a sleeve.
While multiple embodiments are disclosed, still other embodiments of the disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosed apparatus, systems and methods. As will be realized, the disclosed apparatus, systems and methods are capable of modifications in various obvious aspects, all without departing from the spirit and scope of the disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a prior art flat lifter on a cam.
FIG. 2 is a front view of a prior art roller lifter on a cam.
FIG. 3 is a front view of a further prior art roller lifter paired with another lifter via a support.
FIG. 4 is a lower view of an engine block.
FIG. 5 is a front view of an indexed hydraulic roller lifter, according to one embodiment.
FIG. 6 is a front view of an indexed hydraulic roller lifter, according to another embodiment.
FIG. 7A is a cross sectional view of an indexed hydraulic roller lifter, according to another embodiment.
FIG. 7B is a further cross sectional view of an indexed hydraulic roller lifter, according to yet another embodiment.
FIG. 7C is a side view of an indexed roller lifter set inside an engine block.
FIG. 8A is a side view of a prior art flat lifter.
FIG. 8B is a side view of an indexed roller lifter, according to one embodiment.
FIG. 8C is a cross-sectional view of an engine block showing an embodiment of the indexed roller lifter.
FIG. 8D is a further a cross-sectional view of an engine block showing an embodiment of an indexed roller lifter.
FIG. 9 is a side view of an alternate embodiment of an indexed roller lifter having a sleeve.
DETAILED DESCRIPTION
The various implementations disclosed or contemplated herein relate to indexed roller lifters used in internal combustion engines, including hydrogen-powered engines. In various implementations, the disclosed devices, systems and methods relate to indexed roller lifters for use in internal combustion engines. In certain implementations, these lifters have a housing having an indexed portion that abuts against the engine block to prevent rotation. Several aspects and implementations of these lifters are described herein with reference to the figures.
Turning to the drawings in greater detail, a typical hydraulic “flat” lifter 10 is shown in FIG. 1. These flat lifters 10 have elongate, generally cylindrical bodies having a top end 11 and a bottom end 12 having a solid round base 12. In these implementations, the base 12 is constructed and arranged to “ride” on the cam 14 and cam lobe 16 as the cam shaft rotates.
That is, the cam lobe 16 and base 12 are in mechanical communication such that the rotational movement of the cam 14 (shown at reference arrow A) via the cam shaft 18 brings the cam lobe 16 into alignment with the lifter 10 base 12 so as to “raise” the lifter 10 relative to the cam shaft 18, as is well understood in the art, and is shown by reference arrow B. One of skill in the art will appreciate the translation of rotational to linear motion in these components.
It is further understood that in implementations like that of FIG. 1, the lifter 10 base 12 may have an angled, or biased base 12. That is, the angled base 12 is configured to impart a rotational bias during lifter 10 movement relative to the movement the cam lobe 16. That is, while the lifter 10 is being urged away from the cam shaft 18 by the cam lobe 16 (shown by reference arrow B), the angled base 12 is configured to rotate the lifter 10 (shown at reference arrow C) a few degrees per cam shaft 18 rotation (shown at reference arrow A). It is understood that this lifter rotation (again, reference arrow C) prevents the lifter 10 from wearing in any one area. However, lifter rotation also produces friction between the base 12 and cam 14.
As shown in FIG. 2, and according to various further implementations, certain hydraulic roller lifters 20 of are configured to reduce base friction by way of wheels 22. In these implementations, in contrast to the angled base configuration of FIG. 1, the roller lifters 20 have wheels 22 disposed at the base 12 to prevent the “rubbing” friction observed in those implementations.
In implementations like that of FIG. 2, the lifter 20 wheels 22 are indexed. That is, the wheels 22 are configured to allow them to pass over or roll along the surface of the cam lobe 16. Accordingly, it is understood that in these implementations, the lifter 20 provides for wheel 22 against cam 14 contact, thereby reducing friction. It is further understood that these lifter 20 implementations allow for the lifter 20 to be lifted (as shown by reference arrow A) without rotation and losing the roller bearing advantage, while at the same time producing less friction and enhancing engine efficiency.
As shown in FIG. 3, these paired hydraulic roller lifters 20A, 20B in many implementations. These lifters 20A, 20B of these implementations are paired with a cross bar 24 disposed between the respective first ends 11A, 11B. It is understood that the cross bar 24 has been considered necessary to keep the lifters 20A, 20B indexed to the cam (not shown). However, the need for a cross bar 24 has made it impossible to install previous roller lifters 20 in some engines, such as the Ford F-300 inline six cylinder and others. This is because the engine blocks 40 of these implementations are typically cast with a cast iron ridge 42 between the lifters, therefore leaving no room for the cross bars 24, as is shown in FIG. 4.
Turning to the indexed roller lifter 50 implementations, FIGS. 5-6 depict various implementations of the indexed roller lifter 50. In these implementations, the indexed roller lifter 50 is an elongate cylinder comprising a housing or body 52, having a proximal, or “top” end 54 and a distal, or “bottom” end 56. The bottom end 56 in these implementations has support portions 58A, 58B disposed at either side of, and supporting, a wheel 22 via known means such as an axle. Because the wheel is positioned atop the cam in use, it is understood that the wheel 22 reduces the friction and thereby improves efficiency and reduces wear. In this implementation, the indexed roller lifter is therefore an anti-rotation or indexing lifter that can be used on an individual valve system. It is understood that such a lifter can also be used when an odd number of valves is involved, such as a three valve head.
Continuing with the implementations of FIGS. 5-6 and 7A, the body 52 also has at least one substantially flat, or planar indexing region 60 disposed at the proximal end 54 on at least one side of the body 52. In certain implementations, and as shown in FIG. 7A for example, indexing regions 60A, 60B can be disposed on either side of the body 52. In various implementations, these roller lifters 50 are constructed and arranged to be fitted into a lifter tube (shown in FIGS. 7A-B at 74). In these implementations, the lifter tube 74 is an elongate housing 74 defining an internal lumen 64. In various implementations, the hydraulic roller lifter tube 74 is press fitted into the engine block 80 so that it is properly oriented so the roller bearing or wheel 22 on the bottom of the indexed roller lifter 50 rolls smoothly on the cam 14, as will be explained in detail hereafter.
In these implementations, the internal indexing tabs 72A, 72B are disposed within the lumen 64 at the proximal end 64A. These indexing tabs 72A, 72B are constructed and arranged to pair with the indexing regions 60A, 60B of the roller lifter 50 so as to prevent roller lifter 50 rotation within the tube 64 or lumen while allowing it to move vertically (shown by reference arrow B). It is understood that the lumen's proximal end 64A also features a lifter rod opening 61 configured to allow the lifter rod 64 to operate through.
In these implementations, the tube or lumen 64 is indexed 72A, 72B and press fit 74 into the engine block so the internal indexing tabs 72A, 72B align with the indexing regions so as to orient the body 52 such that the wheels 22 are aligned with the rolling surface of the cam 14 (as shown in FIG. 7A). One of skill in the art would appreciate that in certain implementations, the lifter tube 64 can be therefore affixed—such as by press fitting—so that the lifters can be replaced.
Further, with the hydraulic roller lifter tube 64 installed, a indexed roller lifter 50 can fit and be indexed (FIG. 7A) or a regular hydraulic flat lifter 10 will fit into the tube (FIG. 7B)—though longer push rods 76A would be required. It is understood that it is advantageous for the user to be able to utilize either form of roller lifter within the lumen 64. It is further understood that in certain implementations, individual roller lifters 50 can be indexed by adding indexing portions 60 arranged to align with any indexing tabs 72 of an installed tube 74.
It is understood that in implementations like those of FIGS. 5-6 and 7A-B, the wheel 22 is free to rotate in either direction relative to the housing, but is constrained to only “frontward” and “backward.” That is, in these implementations, the wheel 22 cannot pivot or otherwise rotate coaxially with the body 52. FIG. 7A depicts a further implementation of the indexed roller lifter 50 disposed within the lumen 64. In these implementations, the lifter 50 has a wheel 22 and paired indexing regions 60A, 60B on either side of the body 52. In use, and as is shown in FIGS. 7A-7B, in these implementations, the hydraulic roller lifter lumen 64 comprises internal indexing tabs 72 disposed on the inner surface of the lumen 64 that are configured to prevent body 52 rotation.
In these embodiments, and as is also shown in FIG. 7A, the hydraulic roller lifter tube 64 is constructed and arranged to allow the necessary oil 66 to enter the area of the lifter 50. In these implementations, it is understood that hydraulic indexed roller lifters 50 can be used. In these implementations, the oil 66 also provides lubrication for the hydraulic indexed roller lifter's 50 movement up and down, as would be readily understood by the skilled artisan.
In the implementations of FIGS. 7A-B, and as is also shown in FIG. 7C, the indexed roller lifter 50 has a roller lifter tube 64 connection portion 65 configured to allow the roller lifter tube 64 to be connected to the engine block top inside portion 80A through an enclosure tube 82 to totally enclose the push rod 76. When this enclosure tube 82 is installed the push rod (not shown) is isolated from the surrounding environment. This can allow the expansion of the water jacket in some engines. An example of one of one such engine is shown in FIG. 7C.
FIG. 8A is a side view of a typical prior art lifter 10, showing the base 12 positioned over the cam 14 and cam lobe 16. FIG. 7B depicts one implementation of the indexed roller lifter 50, wherein the at least one flat indexing region 60 is disposed at the top end 54 of the indexed roller lifter 50. It is understood that the flat indexing region is configured to abut against a corresponding planar indexing the inside of the hydraulic roller lifter tube 64 so that at least one flat indexing region 60 is prohibited from rotating (because it is substantially planar).
In various implementations, the indexed roller lifter 50 can be used with a protection sleeve 82 that would allow the push rod 76 to be isolated from the surrounding environment. As shown in FIGS. 8C-D, one such application is the passage of push rods through the water jacket 90 of the engine block 80.
FIG. 9 depicts an alternate implementation of an indexed roller lifter 50. In this implementation, the lifter 50 is a two portions, an individual roller 100 body and a lifter sleeve 102. In these implementations, paired tabs 104 are fitted into elongate female openings 106 so as to allow the movement of the roller portion 100 relative to the lifter sleeve 102, as would be understood by one of skill in the art.
It is understood that these implementations are used in very specific racing applications which has a key way to index the roller lifter. This lifter 100 is not hydraulic and will need a separate oiling system to the rocker arms (not shown). It is not compatible with any production roller lifter and requires an offset of the push rod. This lifter 100 is also installed into the top of the sleeve having no means of sealing. In various implementations, this indexed lifter 50 is installed into the hydraulic roller lifter tube 64 described above, thereby giving the option for the lifter/rod assembly to be either completely sealed or open.
In summary, a new design for use of roller lifters in engines has been shown that can enhance engine performance in power, efficiency and longevity.
Although the present invention has been described with reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be realized, the invention is capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
Patent Application
20170342868
