CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Patent Application No. 62/072,480 filed on October 30, 2014. The disclosure of the above application is incorporated herein by reference.

FIELD

[0002] The present disclosure is directed to a hydraulic or mechanical lash adjuster.

BACKGROUND

[0003] Hydraulic or mechanical lash adjusters for internal combustion engines have been in use for many years to eliminate clearance or lash between engine valve train components under varying operating conditions. Lash adjusters can maintain efficiency and reduce noise and wear in the valve train. In some examples, hydraulic lash adjusters can support the transfer of energy from the valve-actuating cam to the valves through hydraulic fluid trapped in a pressure chamber under the plunger.

[0004] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named Inventor, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

SUMMARY

[0005] A hydraulic lash adjuster assembly constructed in accordance to one example of the present disclosure includes a bucket and a hydraulic lash adjuster. The hydraulic lash adjuster is received in the bucket and has a body, a leakdown plunger and a socket. The leakdown plunger is received in the body. The socket is received by the leakdown plunger. The socket and leakdown plunger define a reservoir therebetween. The socket includes a gravity feed arrangement to feed fluid to the reservoir of the leakdown plunger. [0006] According to other features, the socket comprises a top surface, a bottom surface and an intermediate shoulder surface. The intermediate shoulder surface abuts the leakdown plunger. The gravity feed arrangement comprises at least one aperture defined through the socket. The at least one aperture comprises a first pair of apertures that lead to a second pair of apertures. The apertures of the second pair of apertures are offset from the apertures of the first pair. The second pair of apertures provide a surface tension seal to the top surface of the leakdown plunger and route fluid into the reservoir.

[0007] According to additional feature, the leakdown plunger defines a recirculation passageway including an annular notch portion and an aperture portion. The socket can be enclosed in the bucket. A push tube guide can enclose the socket within the bucket.

[0008] A hydraulic lash adjuster assembly constructed in accordance to other features of the present disclosure can include a bucket and a hydraulic lash adjuster received in the bucket. The hydraulic lash adjuster can have a body, a leakdown plunger and a socket assembly. The leakdown plunger can be received in the body. The socket assembly can be received by the leakdown plunger. The socket assembly and leakdown plunger can define a reservoir therebetween. The socket assembly can include a socket and a valve member. The socket can include a valve seat and a valve restraint. The valve member can move relative to the socket. The valve member can engage the valve restraint in a first orientation and engage the valve seat in a second orientation. Fluid is permitted to flow between the valve member and the valve restraint in the first orientation. Fluid is precluded from flowing between the valve member and the valve seat in the second orientation.

[0009] According to other features, the valve member can comprise a plate. The valve member can be captured in the socket by the valve restraint. The valve restraint can include a shelf. In one configuration the shelf can be non-flat. In another configuration the shelf can be irregular shaped. In an alternate configuration the valve restraint comprises fingers. The fingers can be radially offset relative to each other.

[0010] A hydraulic lash adjuster assembly constructed in accordance to other features of the present disclosure can include a hydraulic lash adjuster having a body, a leakdown plunger and a socket assembly. The leakdown plunger can be received in the body. The socket assembly can be received by the leakdown plunger. The socket assembly and leakdown plunger can define a reservoir therebetween. The socket assembly can include a socket and a valve member. The socket can include a valve seat and a valve restraint. The valve member can be captured by a valve restraint mounted in the socket. The valve member can move relative to the socket. The valve member can engage the valve restraint in a first orientation and engage the valve seat in a second orientation. Fluid is permitted to flow between the valve member and the valve restraint in the first orientation. Fluid is precluded from flowing between the valve member and the valve seat in the second orientation.

[0011] According to other features the hydraulic lash adjuster can further include a bucket. The hydraulic lash adjuster can be received in the bucket. The valve member can comprise a ball. The valve restraint can comprise a cage. The cage can define passages therein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0013] FIG. 1 is a perspective view of a hydraulic lash adjuster constructed in accordance to one example of the present disclosure;

[0014] FIG. 2 is a cross-sectional view taken through section lines 2 - 2 in FIG. 1 ;

[0015] FIG. 3 is a side view of a leakdown plunger of a hydraulic lash adjuster constructed in accordance to one example of the present disclosure;

[0016] FIG. 4 is bottom view of a socket of a hydraulic lash adjuster constructed in accordance to one example of the present disclosure;

[0017] FIG. 5 is a cross-sectional view taken through section lines 5 - 5 in FIG. 4;

[0018] FIG. 6 is a cross-sectional view of a socket assembly with a valve arrangement constructed in accordance to another example of the present disclosure;

[0019] FIG. 7 is a cross-sectional view of a socket assembly with a valve arrangement constructed in accordance to another example of the present disclosure; [0020] FIG. 8 is a cross-sectional view of a socket assembly with a valve arrangement constructed in accordance to another example of the present disclosure;

[0021] FIG. 9 is bottom view of a socket of a hydraulic lash adjuster constructed in accordance to another example of the present disclosure;

[0022] FIG. 10 is a cross-sectional view taken through section lines 10 - 10 in FIG. 9; and

[0023] FIG. 11 is the cross-sectional view of FIG. 10 and shown retained within a body with a C-clip according to other features.

DETAILED DESCRIPTION

[0024] A plurality of different examples of the present teachings is shown in the Figures of the application. Similar features are shown in the various aspects of the present disclosure. Similar features have been numbered with a common reference numeral and have been differentiated by an alphabetic suffix. Also, to enhance consistency, the structures in any particular drawing share the same alphabetic suffix even if a particular feature is shown in less than all of the disclosed aspects of the present teachings. Similar features are structured similarly, operate similarly, and/or have the same function unless otherwise indicated by the drawings or this specification. Furthermore, particular features of one example can replace corresponding features in another example or can supplement other examples unless otherwise indicated by the drawings or this specification.

[0025] in some operating environments, it may be desirable to install hydraulic lash adjusters into a dry engine block and in subsequent assembly operations invert the engine for an extended period. In existing hydraulic lash adjusters, at least some of the oil in a reservoir of the hydraulic lash adjuster would leak out. Further, once the engine is fully assembled and started, the high pressure chamber may ingest the air from the reservoir and several minutes (twenty or more) may pass before the high pressure chamber refills with oil. Using a biased, normally-open check valve would allow quicker filling as the normally-open valve arrangement pumps up more quickly than a normally- closed arrangement. [0026] The normaliy-open valve arrangement also allows for shipping the hydraulic lash adjuster with the reservoir empty. Since the normally-open valve arrangement dispels an amount of fluid or air with each stroke, it allows for shipping the hydraulic lash adjuster with the reservoir empty. Any air that is ingested to the high pressure chamber will more naturally be pumped out with far fewer strokes. It will be appreciated in light of the disclosure that it can be shown that this phenomenon can be optimized by placing the normally open check valve as high in the high pressure chamber as possible. FIGS. 1 - 3 illustrate a hydraulic lash adjuster having a recirculation passageway to allow for passage of fluid from a high pressure chamber to the reservoir to more quickly fill the reservoir.

[0027] Referring now to FIGS. 1 - 4, a hydraulic lash adjuster assembly 10 can include a bucket 12 and a hydraulic lash adjuster 14. The hydraulic lash adjuster 14 can be received in the bucket 12. The hydraulic lash adjuster 14 can include a body 16, a leakdown plunger 18, and socket 20. The leakdown plunger 18 can be received in the body 16. A high pressure chamber 22 can be defined between the body 16 and the leakdown plunger 18. A reservoir 24 can be defined between leak down plunger 18 and the socket 20. The socket 20 can substantially close the reservoir 24 and can itself be enclosed in the bucket 12 with a push tube guide 42 or clip.

[0028] A spring 26 can be disposed in the high pressure chamber 22. The spring 26 can bias the body 16 and the leakdown plunger 18 apart along a central axis 28 of the assembly 10. The extent of relative travel between the leakdown plunger 18 and the body 16 is referenced at 30.

[0029] A normally-open valve arrangement 32 can be mounted to the leakdown plunger 18. The normally-open valve arrangement 32 can be positioned between the high pressure chamber 22 and the reservoir 24. The normally-open valve arrangement 32 can include a ball or valve member 34, a spring 36, and a retainer 38. The leakdown plunger 18 can define a valve seat 40. The spring 36 can urge the valve member 34 toward the high pressure chamber 22 and against the retainer 38. A predetermined level of differential pressure between high pressure chamber 22 and reservoir 24 can urge the valve member 34 toward the reservoir 24, overcoming the spring 36, and seating the valve member 34 on the valve seat 40. [0030] A recirculation passageway 44 can be defined by the leakdown plunger 18. The recirculation passageway 44 assists the assembly 10 to pump up from dry or spongy more quickly by returning any oil pumped out of the high pressure chamber 22 to the reservoir 24. The recirculation passageway 44 can include an annular notch portion 46 formed in an outer surface of the leakdown plunger 18. The recirculation passageway 44 can also include an aperture portion 48 extending through the leakdown plunger 18. In operation, fluid can pass between the outside surface of the leakdown plunger 18 and an inside surface of the body 16, collect in the annular notch portion 46, and pass into the reservoir 24 through the aperture portion 48. The recirculation passageway 44 allows the assembly 10 to pump up from dry or spongy relatively quickly.

[0031] FIG. 5 illustrates an alternative socket 20a according to the present disclosure. The socket 20a can be incorporated into a hydraulic lash adjuster assembly such as the hydraulic lash adjuster assembly 10 described herein. The socket 20a extends between a top surface 50a, a bottom surface 52a and an intermediate shoulder surface 53a. The intermediate shoulder surface 53a can abut a leakdown plunger. The socket 20a includes a gravity feed arrangement to feed fluid to a reservoir of the leakdown plunger. The gravity feed arrangement includes apertures 54a, 56a, 58a, 60a.

[0032] Two apertures 54a and 56a lead to machined apertures 58a, 60a that are offset to provide a surface tension seal to the top of the leakdown plunger and route fluid into the reservoir. Vent indentations can be defined in the socket 20a to vent out any air in the reservoir as fluid fills the reservoir. This would provide a "flow through" design such that any soot or other contaminate would not accumulate. The socket 20a depicted in FIGS. 4 and 5 can be a manner to gravity feed oil from the outer diameter of a push tube and/or rocker arm (not shown) down into the reservoir leakdown plunger. The result would be a hydraulic lash adjuster assembly that would not need a pressure feed to it to keep it full, thereby reducing the demand on the oil pump.

[0033] FIGS. 6 - 8 illustrate alternative socket assemblies 62b, 62c, and 62d that can prevent fluid from draining from a reservoir if the engine is inverted for an extended period. As shown in FIG. 6, a socket assembly 62b can include a socket 20b and a valve member or plate 64b. The socket 20b can define a valve seat 66b. The socket 20b can also define a valve restraint or fingers 68b. The fingers 68b are at least one of radially offset from each other, irregular shape and non-flat. FIG. 6 illustrates the position of the valve member 64b when the engine is not inverted. When non-inverted or right side up, fluid is permitted to flow between the plate 64b and the fingers 68b. Explained further, the irregular shape of the fingers 68b does not allow a seal to be achieved between the plate 64b and the fingers 68b. Other configurations or geometries are contemplated for permitting fluid flow in one direction while inhibiting flow in an opposite direction. The valve member 64b can be captured by the valve restraint 68b. When the engine is inverted, the valve member 64b can be induced by gravity to seat against the valve seat 66b and inhibit fluid from escaping the reservoir.

[0034] FIG. 7 illustrates a socket assembly 62c having a socket 20c and a valve member or plate 64c. The socket 20c can define a valve seat 66c. The illustrated position of the valve member 64c is between the position when the engine is not inverted and the position when the engine is inverted. The valve member 64c can be captured by a valve restraint or shelf 70c defined by the leakdown plunger 18c. When the engine is inverted, the valve member 64c can be induced by gravity to seat against the valve seat 66c and prevent fluid from escaping the reservoir 24c. When the engine is non-inverted or right side up, fluid is permitted to flow between the plate 64c and the shelf 70c. Explained further, the irregular or non-flat shape of the shelf 70c does not allow a seal to be achieved between the plate 64c and the shelf 70c.

[0035] FIG. 8 illustrates a socket assembly 62d having a socket 20d and a valve member 64d. The socket 20d can define a valve seat 66d. The valve member 64d can be captured by a valve restraint 68d mounted on the socket 20d. The valve member 64d can be a ball. The valve restraint 68d can be a cage having passages 80 therethrough. The illustrated position of the valve member 64d is between the position when the engine is not inverted and the position when the engine is inverted. When the engine is inverted, the valve member 64d can be induced by gravity to seat against the valve seat 66d and prevent fluid from escaping the reservoir. When non-inverted or right side up, fluid is permitted to flow around the valve member 64d and through the passages 80 in the cage of the valve restraint 68d. [0036] FIGS. 9-11 illustrate an assembly 110 that includes a socket 120 received in a body 112. The socket 120 can include similar features as any of the sockets 20a, 20b, 20c and 20d described above. In the configuration shown in FIGS. 9-1 1 , the body 112 extends up around the socket 120 and is retained with a C-clip 122. Other retention methods may be used. The same gravity feed features described above may be incorporated into the configuration shown in FIGS. 9-1 1.

[0037] The foregoing description of the aspects of the present teachings has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular example are generally not limited to those particular aspects, but, where applicable, are interchangeable and can be used in a selected examples, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.