WO2008002746A2

WO2008002746A2 - Coupling device

Info

Publication number: WO2008002746A2
Application number: PCT/US2007/070377
Authority: WO
Inventors: Matthew J. Deierlein
Original assignee: Timken Us Corporation
Priority date: 2006-06-26
Filing date: 2007-06-05
Publication date: 2008-01-03
Also published as: WO2008002746A3

Abstract

The present invention provides a device adapted to couple a finger follower (14) and a hydraulic lash adjuster (18) for use in a valve train of an engine. The hydraulic lash adjuster (18) includes a plunger (34) defining a longitudinal axis. The finger follower (14) includes a pocket for receiving the plunger (74). The device includes a resilient clip (50) having a first portion (74) configured to engage the finger follower (14) and a second portion including an aperture for receiving the plunger (34) and at least one retainer (54) having an aperture (66) therethrough for receiving the plunger (34). The retainer (54) is coupled to the plunger (34). The second portion (74) of the clip (50) is positioned adjacent the at least one retainer (54) to substantially axially secure the second portion (74) of the clip( 50) to the plunger (34).

Description

COUPLING DEVICE

RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application Serial

No. 60/805,783 filed on June 26, 2006, the entire contents of which is incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to couplings, and more particularly to couplings for use in connecting valve train components of an engine.

BACKGROUND OF THE INVENTION

[0003] When creating an assembly of components, it is often desirable to create multiple sub-assemblies, or "unitize" multiple individual components, to simplify or facilitate the assembly process. A valve train of an engine includes many components, and depending on the number of cylinders in the engine, assembling all of the valve train components may require a significant amount of time and precision when handling and connecting the individual components.

SUMMARY OF THE INVENTION

[0004] Unitizing two or more valve train components in an engine can reduce the amount of time and precision required when handling and connecting the unitized components.

[0005] The present invention provides, in one aspect, a device adapted to couple a finger follower and a hydraulic lash adjuster for use in a valve train of an engine. The hydraulic lash adjuster includes a plunger defining a longitudinal axis. The finger follower includes a pocket for receiving the plunger. The device includes a resilient clip having a first portion configured to engage the finger follower and a second portion including an aperture for receiving the plunger and at least one retainer having an aperture therethrough for receiving the plunger. The retainer is coupled to the plunger. The second portion of the clip is positioned adjacent the at least one retainer to substantially axially secure the second portion of the clip to the plunger.

[0006] The present invention provides, in another aspect, a unitized valve train assembly including a fmger follower including a pocket, and a hydraulic lash adjuster including a plunger received within the pocket of the finger follower. The plunger defines a longitudinal axis. The unitized valve train assembly also includes a resilient clip having a first portion engageable with the finger follower and a second portion having an aperture therethrough. The plunger is received within the aperture. The unitized valve train assembly also includes at least one retainer having an aperture therethrough. The plunger is received within the aperture in the retainer and coupled to the retainer. The second portion of the clip is positioned adjacent the at least one retainer to substantially axially secure the second portion of the clip to the plunger.

[0007] The present invention provides, in yet another aspect, a method of coupling a finger follower and a hydraulic lash adjuster for use in a valve train of an engine. The fmger follower has a pocket for receiving a plunger of the hydraulic lash adjuster. The method includes providing a resilient clip having an aperture therethrough, providing a retainer having an aperture therethrough, inserting the plunger through the aperture in the resilient clip, inserting the plunger through the aperture in the retainer after the plunger is inserted through the aperture in the resilient clip, securing the retainer to the plunger, and positioning the plunger within the pocket of the finger follower. [0008] Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. l is a front perspective view of a unitized valve train assembly, including a coupling device of the present invention coupling a roller finger follower and a hydraulic lash adjuster.

[0010] FIG. 2 is a side perspective view of the unitized valve train assembly of FIG.

1.

[0011] FIG. 3 is a side view of the unitized valve train assembly of FIG. 1.

[0012] FIG. 4 is a top perspective view of the unitized valve train assembly of FIG. 1.

[0013] FIG. 5 is a side perspective view of the hydraulic lash adjuster of the unitized valve train assembly of FIG. 1.

[0014] FIG. 6 is a side perspective view of the hydraulic lash adjuster of FIG. 5, illustrating a first retainer of the coupling device of FIG. 1 coupled with the hydraulic lash adjuster.

[0015] FIG. 7 is a side perspective view of the hydraulic lash adjuster and first retainer of FIG. 6, illustrating a resilient clip of the coupling device of FIG. 1 supported by the first retainer.

[0016] FIG. 8 is a side perspective view of the hydraulic lash adjuster, first retainer, and resilient clip of FIG. 7, illustrating a second retainer coupled with the hydraulic lash adjuster to substantially secure the clip relative to the hydraulic lash adjuster.

[0017] FIG. 9 is a cross-sectional view of one of the retainers of the coupling device of FIG. 1. [0018] FIG. 10 is a side perspective view of the resilient clip of the coupling device of

FIG. 1.

[0019] FIG. 11 is an exploded, side perspective view of the coupling device of FIG. 1.

[0020] FIG. 12 is an assembled, side perspective view of the coupling device of FIG.

1.

[0021] FIG. 13 is a top perspective, partial cross-sectional view of the coupling device of FIG. 1 coupled to the hydraulic lash adjuster.

[0022] FIG. 14 is a side, partial cross-sectional view of the retainers of the coupling device of FIG. 1 coupled to the hydraulic lash adjuster.

[0023] FIG. 15 is a side, partial cross-sectional view of the coupling device of FIG. 1 coupled to the hydraulic lash adjuster.

[0024] FIG. 16 is a side, partial cross-sectional view of the unitized valve train assembly of FIG. 1, illustrating the roller finger follower being positioned to engage the hydraulic lash adjuster.

[0025] FIG. 17 is a side, partial cross-sectional view of the unitized valve train assembly of FIG. 1, illustrating the coupling device engaging the roller finger follower.

[0026] FIG. 18 is a side, partial cross-sectional view of the unitized valve train assembly of FIG. 1, illustrating the coupling device coupling the roller finger follower and the hydraulic lash adjuster.

[0027] FIG. 19 is a side, partial cross-sectional view of the unitized valve train assembly of FIG. 1, illustrating the roller finger follower in a first orientation relative to the coupling device and hydraulic lash adjuster. [0028] FIG. 20 is a side, partial cross-sectional view of the unitized valve train assembly of FIG. 1, illustrating the roller finger follower in a second orientation relative to the coupling device and hydraulic lash adjuster.

[0029] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms "mounted," "connected," "supported," and "coupled" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, "connected" and "coupled" are not restricted to physical or mechanical connections or couplings.

DETAILED DESCRIPTION

[0030] FIGS. 1-4 illustrate a unitized valve train assembly 10 including a rocker arm or a spherical-end pivoting, roller cam follower assembly or roller finger follower 14, a hydraulic lash adjuster 18, and a coupling device 22 for unitizing or coupling the follower 14 and the adjuster 18. The follower 14 includes a ball socket 26 (see FIGS. 16-20) having a pocket 30 in which the spherical-pivot component of the adjuster 18, customarily the piston or plunger 34 of the adjuster 18, is received (see FIGS. 5-8, 13-15, and 16-20). Specifically, the adjuster 18 includes a housing 38 in which the plunger 34 is supported, and the plunger 34 includes a shank 42 and a spherical end portion 46, which engages the pocket 30 of the follower 14. Such a unitized valve train assembly 10 may be used, for example, in an engine having an overhead camshaft configuration.

[0031] With reference to FIGS. 11 and 12, the coupling device 22 includes a resilient clip 50 and a pair of retainers 54, commercially known as "push retainers," each of which includes a substantially planar portion 58 and an approximately conical portion 62 located radially inwardly of the substantially planar portion 58 (see also FIG. 9). The retainers 54 also each include an aperture 66 having a diameter Dl. In its pre-assembled state, the inside diameter Dl of the retainers 54 is slightly less than an outer diameter D2 of the plunger shank 42 to provide an interference fit between the retainers 54 and the plunger shank 42 during assembly of the coupling device 22 onto the adjuster 18 (see FIG. 14). The retainers 54 may be made from steel or any other material suitable to provide an interference fit with the plunger shank 42.

[0032] With reference to FIGS. 10 and 11, the clip 50 is comprised of a single piece of resilient material (e.g., sheet steel), and includes a first or upper portion 70 engageable with the follower 14 and a second or lower portion 74 configured to be disposed around the plunger 34. The upper portion 70 of the clip 50 includes a tab 78 oriented in such a manner that it can extend around the ball socket 26 of the follower 14 (see FIGS. 19-20). Specifically, the tab 78 includes an arcuate lip portion 82 (see FIGS. 10-12) engageable with the ball socket 26 of the follower 14 to facilitate the connection of the clip 50 and the follower 14, and to provide resistance to the disconnection of the clip 50 and the follower 14. With reference to FIG. 4, the width of the tab 78 may span either a small portion of, or nearly the entire width between respective side walls 86 of the follower 14.

[0033] In the illustrated construction of the clip 50, the lower portion 74 of the clip 50 includes a loop 90 having an aperture 94 therethrough (see FIGS. 10 and 11). The aperture 94 has a diameter D3 greater than the outer diameter D2 of the plunger shank 42 (see also FIG. 15), such that an interference fit between the clip 50 and the plunger shank 42 does not result when the plunger 34 is inserted through the aperture 94. The diameter D3 of the aperture 94 is sufficiently large enough to allow the clip 50 to freely rotate about a central axis 98 of the adjuster 18 (which is also a longitudinal axis 98 of the plunger 34) relative to the plunger 34. However, in alternate constructions of the clip 50, the exterior of the lower portion 74 may be substantially rectangular rather than being shaped as a loop 90.

[0034] With reference to FIGS. 5-8, a sequence of assembling the coupling device 22 onto the adjuster 18 is shown. First, the bare adjuster 18 is provided, as shown in FIG. 5. The lower retainer 54 is then coupled to the adjuster 18 by inserting the plunger 34 through the aperture 66 in the retainer 54. Because the inside diameter Dl of the retainer 54, in its pre-assembled state, is slightly less than the outer diameter D2 of the plunger shank 42, the conical portion 62 of the retainer 54 may slightly deform to stretch around the larger diameter D2 of the plunger shank 42. Such deformation of the retainer 54 provides the interference fit with the plunger shank 42 to rigidly secure the retainer 54 onto the plunger 34.

[0035] After the lower retainer 54 is coupled to the plunger 34, the clip 50 is positioned onto the adjuster 18 by inserting the plunger 34 through the aperture 94 in the lower portion 74 of the clip 50 (see FIG. 7). As discussed above, the diameter D3 of the aperture 94 in the clip 50 is greater than the outer diameter D2 of the plunger shank 42, however, the diameter D3 is less than an outer diameter D4 of the retainer 54 such that the lower portion 74 of the clip 50 may be supported on the substantially planar portion 58 of the lower retainer 54 (see also FIGS. 13 and 15). Preferably, the diameter D3 is large enough so that the lower portion 74 of the clip 50 is supported solely by the substantially planar portion 58 of the lower retainer 54, allowing the lower portion 74 of the clip 50 to lie substantially flat on the substantially planar portion 58 of the lower retainer 54. [0036] With reference to FIG. 8, the upper retainer 54 is coupled to the adjuster 18, after the clip 50 is positioned onto the lower retainer 54, in the same way as the lower retainer 54. In the illustrated construction, the conical portions 62 of the respective retainers 54 engage each other in nested relation when the retainers 54 are stacked on top of each other in the final assembly of the coupling device 22 on the plunger 34 (see FIGS. 13-15). However, in alternate constructions of the coupling device 22, the thickness of the loop 90 in the lower portion 74 of the clip 50 may result in a stacked-clip configuration in which the conical portions 62 of the respective retainers 54 do not engage each other.

[0037] As shown in FIG. 14, an axial gap G between the substantially planar portions

58 of the respective retainers 54 results from stacking the retainers 54 (the clip 50 is omitted for clarity). As shown in FIG. 15, the loop 90 in the lower portion 74 of the clip 50 is retained within the axial gap G. The axial gap G may be slightly greater than or equal to the thickness of the loop 90. Preferably, the width of the axial gap G is nominally larger than the thickness of the loop 90 (e.g., no more than a few thousandths of an inch), allowing the clip 50 to rotate freely about the central axis 98 of the adjuster 18, but preventing the clip 50 from substantially translating along the central axis 98 or tilting with respect to the retainers 54. The subassembly of the adjuster 18 and the coupling device 22 is fully unitized and can be handled without substantial concern of causing unintentional disassembly. In an alternative construction, the lower retainer 54 could be eliminated such that only the upper retainer 54 is present and operates as a flange or shelf to prevent upward movement of the clip 50 relative to the adjuster 18.

[0038] With reference to FIGS. 16-18, a sequence of assembling the follower 14 and the unitized adjuster 18 and coupling device 22 is shown. FIG. 16 illustrates the follower 14 oriented such that its pocket 30 may receive the spherical end portion 46 of the plunger 34.

FIG. 17 illustrates the arcuate lip portion 82 of the tab 78 engaging an upper surface 102 of the ball socket 26, causing the clip 50 to deflect or elastically bend to an "open" position to allow insertion of the spherical end portion 46 of the plunger 34 in the pocket 30 of the follower 14. As the follower 14 and adjuster 18 are brought together, maximum deflection of the clip 50 occurs at an apex 106 of the upper surface 102 of the ball socket 26. After the arcuate lip portion 82 of the tab 78 passes over the apex 106 and the pocket 30 of the follower 14 receives the spherical end portion 46 of the plunger 34, the clip 50 will resume its undeflected shape or its "closed" position to secure the follower 14 to the adjuster 18, as shown in FIG. 18.

[0039] The follower 14 and adjuster 18 can now be handled as a unit, without substantial concern that the adjuster 18 may be unintentionally separated from the follower 14. To separate the adjuster 18 and the follower 14, the arcuate lip portion 82 must be forced to pass over the apex 106 of the upper surface 102 of the ball socket 26, thereby causing the clip 50 to deflect back to its "open" position to allow removal of the spherical end portion 46 of the plunger 34 from the pocket 30 of the ball socket 26. The resilient property of the clip 50 allows it to be bent slightly to permit insertion and removal of the follower 14 between the tab 78 of the clip 50 and the spherical end portion 46 of the plunger 34 without permanently distorting the clip 50 to the extent that its retention is substantially compromised.

[0040] With reference to FIGS. 19 and 20, the follower 14 is loosely, but positively retained to the adjuster 18 by the clip 50. When installed in an engine application, sufficient clearance is provided by the geometry of the clip 50 and retainers 54 such that the follower 14 is able to pivot on the spherical end portion 46 of the plunger 34 through the necessary range of operating angles without causing damage to or binding of any components, including the follower 14 and the adjuster 18 themselves, due to interference. Contact between the clip 50 and the follower 14 is limited to the locations where the tab 78 may contact the side walls 86 of the follower 14, and where the tab 78 may occasionally contact the ball socket 26 of the follower 14.

[0041] The coupling device 22 facilitates handling of the follower 14 and the adjuster

18 as a unit, without substantial concern that the follower 14 and the adjuster 18 may become unintentionally separated, without requiring any special features on either the follower 14 or the adjuster 18, such as an undercut of the plunger shank 42; and without impeding the intended motion of either the follower 14 or the adjuster 18, particularly the rotation of the plunger 34 in its housing 38.

[0042] Once installed in a fully assembled engine, the coupling device 22 is no longer needed to keep the follower 14 assembled to the adjuster 18. Rather, the coupling device 22 is only needed to keep the follower 14 from unintentionally separating from the adjuster 18 when the engine is only partially assembled. Therefore, during operation of the fully assembled engine, little or no contact between the upper surface 102 of the ball socket 26 and the underside of the tab 78 or arcuate lip portion 82 occurs because repeated contact may lead to wear or breakage of the clip 50. Contact between the upper surface 102 of the ball socket 26 and the underside of the tab 78 or arcuate lip portion 82 usually only occurs during assembly, either when the follower 14 is installed onto the adjuster 18, or when the follower 14 is being prevented from unintentionally separating from the adjuster 18.

[0043] Various features of the invention are set forth in the following claims.

Claims

CLAIMSWhat is claimed is:

1. A device adapted to couple a finger follower and a hydraulic lash adjuster for use in a valve train of an engine, the hydraulic lash adjuster having a plunger defining a longitudinal axis, the finger follower having a pocket for receiving the plunger, the device comprising: a resilient clip having a first portion configured to engage the finger follower and a second portion including an aperture for receiving the plunger; and at least one retainer having an aperture therethrough for receiving the plunger; wherein the retainer is coupled to the plunger, and wherein the second portion of the clip is positioned adjacent the at least one retainer to substantially axially secure the second portion of the clip to the plunger.

2. The coupling device of claim 1, wherein the at least one retainer includes a first retainer and a second retainer, and wherein the second portion of the clip is positioned between the first retainer and the second retainer.

3. The coupling device of claim 2, wherein each of the first and second retainers includes a planar portion and a conical portion radially inwardly of the planar portion, and wherein the respective conical portions of the first and second retainers engage each other when the first and second retainers are coupled to the plunger.

4. The coupling device of claim 2, wherein each of the first and second retainers includes a planar portion, wherein the respective planar portions of the first and second retainers form a gap therebetween when the first and second retainers are coupled to the plunger, and wherein the gap is slightly greater than or equal to a thickness of the second portion of the clip.

5. The coupling device of claim 2, wherein the second portion of the clip is permitted to rotate about the longitudinal axis, and wherein the second portion of the clip is substantially prevented from moving in a direction parallel to the longitudinal axis.

6. The coupling device of claim 1 , wherein an interference fit between the aperture in the retainer and the plunger couples the retainer to the plunger.

7. The coupling device of claim 1, wherein the first portion of the resilient clip includes a tab and an arcuate lip portion on a distal end of the tab.

8. The coupling device of claim 7, wherein the tab and the second portion of the resilient clip are substantially parallel to one another.

9. The coupling device of claim 7, wherein at least a portion of the arcuate lip portion extends in a direction toward the second portion of the resilient clip.

10. The coupling device of claim 1, wherein the resilient clip is made from steel.

11. The coupling device of claim 1, wherein the aperture in the resilient clip has a diameter greater than a diameter of the plunger.

12. A unitized valve train assembly comprising: a finger follower including a pocket; a hydraulic lash adjuster including a plunger received within the pocket of the finger follower, the plunger defining a longitudinal axis; a resilient clip including a first portion engageable with the finger follower; a second portion having an aperture therethrough, the plunger received within the aperture; and at least one retainer having an aperture therethrough, the plunger received within the aperture in the retainer and coupled to the retainer; wherein the second portion of the clip is positioned adjacent the at least one retainer to substantially axially secure the second portion of the clip to the plunger.

13. The unitized valve train assembly of claim 12, wherein the at least one retainer includes a first retainer and a second retainer, and wherein the second portion of the clip is positioned between the first retainer and the second retainer.

14. The unitized valve train assembly of claim 13, wherein each of the first and second retainers includes a planar portion and a conical portion radially inwardly of the planar portion, and wherein the respective conical portions of the first and second retainers engage each other when the first and second retainers are coupled to the plunger.

15. The unitized valve train assembly of claim 13, wherein each of the first and second retainers includes a planar portion, wherein the respective planar portions of the first and second retainers form a gap therebetween when the first and second retainers are coupled to the plunger, and wherein the gap is slightly greater than or equal to a thickness of the second portion of the clip.

16. The unitized valve train assembly of claim 12, wherein the second portion of the clip is permitted to rotate about the longitudinal axis, and wherein the second portion of the clip is substantially prevented from moving in a direction parallel to the longitudinal axis.

17. The unitized valve train assembly of claim 12, wherein an interference fit between the aperture in the retainer and the plunger couples the retainer to the plunger.

18. The unitized valve train assembly of claim 12, wherein the first portion of the resilient clip includes a tab and an arcuate lip portion on a distal end of the tab.

19. The unitized valve train assembly of claim 18, wherein the tab and the second portion of the resilient clip are substantially parallel to one another.

20. The unitized valve train assembly of claim 18, wherein at least a portion of the arcuate lip portion extends in a direction toward the second portion of the resilient clip.

21. The unitized valve train assembly of claim 12, wherein the resilient clip is made from steel.

22. The unitized valve train assembly of claim 12, wherein the aperture in the resilient clip has a diameter greater than a diameter of the plunger.

23. A method of coupling a finger follower and a hydraulic lash adjuster for use in a valve train of an engine, the finger follower having a pocket for receiving a plunger of the hydraulic lash adjuster, the method comprising: providing a resilient clip having an aperture therethrough; providing a retainer having an aperture therethrough; inserting the plunger through the aperture in the resilient clip; inserting the plunger through the aperture in the retainer after the plunger is inserted through the aperture in the resilient clip; securing the retainer to the plunger; and positioning the plunger within the pocket of the finger follower.

24. The method of claim 23, wherein the retainer is a first retainer, and wherein the method further includes: providing a second retainer having an aperture therethrough; inserting the plunger through the aperture in the second retainer before inserting the plunger through the aperture in the resilient clip; and securing the second retainer to the plunger.

25. The method of claim 24, further comprising engaging the first and second retainers in nested relation on the plunger.

26. The method of claim 23, wherein securing the retainer to the plunger includes providing an interference fit between the retainer and the plunger.

27. The method of claim 23, wherein positioning the plunger within the pocket of the finger follower occurs after inserting the plunger through the aperture in the retainer.

28. The method of claim 23, wherein positioning the plunger within the pocket of the finger follower includes deflecting a portion of the resilient clip over a portion of the finger follower.