Variable Valve Lift Rocker Arm Assembly

Abstract

The variable valve lift rocker arm assembly (1) includes a latch shaft assembly (30, 908) including a roller latch assembly (61) and a first latch receiver assembly (62, 916), and an outer body (11) configured to rotate about a rocker shaft (18), the outer body (11) including at least a valve end (12, 13, 902, 903) and a cam end (19, 20, 21, 909, 910, 911) including an outer shaft bore (291) for seating the first latch receiver assembly of the latch shaft assembly. ), an inner body (22, 906, 907) configured to rotate about the rocker shaft, the inner body (22, 906, 907) having an inner axle bore (32) configured to seat a roller latch assembly of the latch axle assembly, a primary roller (23, 905) operably coupled to the outer body, and a secondary roller (24, 904) operably coupled to the inner body, wherein the roller latch assembly and the first latch receiver assembly are configured to selectively operably couple the outer body to the inner body.

Description

[Technical field]

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 159,521, filed March 11, 2021, which is incorporated by reference in its entirety.

[0002] The present application relates to rocker arm assemblies, and more particularly to a variable valve lift rocker arm assembly having switchable rollers for use, for example, in the valve train of an internal combustion engine, that allows for deactivation and the use of other variable valve actuation techniques. [Background technology]

[0003] An internal combustion engine may include a valve train assembly including rocker arms for controlling the opening and closing of intake and exhaust valves. The rocker arms are reciprocating levers that convert the radial motion of a rotating camshaft lobe into linear motion that controls the opening and closing of the valves. The rocker arms are attached to rocker shafts with one end in direct or indirect contact with the rotating camshaft lobe and the other end in structural contact with the valves.

[0004] Variable valve actuation mechanisms, such as cylinder deactivation and variable valve lift, have been introduced in internal combustion engines to improve engine performance, fuel economy and / or emissions. Switchable rocker arms can be used to support the variable valve actuation mechanisms.

[0005] The description provided herein is intended to provide a comprehensive context for the present disclosure, and the inventors' work, to the extent described in this section, is not admitted expressly or impliedly as prior art to the present disclosure, as are aspects of the specification that may not otherwise be considered prior art at the time of filing. Summary of the Invention

[0006] The variable valve lift rocker arm assembly may include a latch shaft assembly comprising a roller latch assembly and a first latch receiver assembly, an outer body configured to rotate about the rocker shaft, the outer body comprising at least a valve end and a cam end comprising an outer axial bore for seating the first latch receiver assembly of the latch shaft assembly, an inner body configured to rotate about the rocker shaft, the inner body comprising an inner axial bore configured to seat the roller latch assembly of the latch shaft assembly, a primary roller operably coupled to the outer body, and a secondary roller operably coupled to the inner body, the roller latch assembly and the first latch receiver assembly configured to selectively operably couple the outer body to the inner body.

[0007] The variable valve lift rocker arm assembly may include a roller latch assembly seated within a shaft bushing within a secondary roller.

[0008] The variable valve lift rocker arm assembly can include a roller latch assembly including a first latch pin configured to move between a latched position in which the first latch pin engages the first latch receiver assembly to lock relative rotation between the inner body and the outer body and an unlatched position in which the first latch pin disengages from the first latch receiver assembly to allow relative rotation between the inner body and the outer body.

[0009] The variable valve lift rocker arm assembly can include a roller latch assembly further comprising a second latch pin, the latch shaft assembly further comprising a second latch receiver assembly within the outer body, the second latch pin configured to engage with the second latch receiver assembly in the latched position and the second latch pin configured to disengage from the second latch receiver assembly in the unlatched position.

[0010] The variable valve lift rocker arm assembly can include a first latch receiver configured to selectively press against the roller latch assembly to selectively unlatch the inner body from the outer body.

[0011] The variable valve lift rocker arm assembly includes a latch shaft assembly including a first roller latch assembly, a second roller latch assembly, a first latch receiver assembly, and a second latch receiver assembly; an outer body including at least one valve end, an outer bore shaft, and an axial bore for receiving a first portion of the latch shaft assembly; a first inner body including a first inner bore shaft and a first inner axial bore for receiving a second portion of the latch shaft assembly; a second inner body including a second inner bore shaft and a second inner axial bore for receiving a third portion of the latch shaft assembly; and a first roller latch assembly and a first inner latch assembly. The latch shaft assembly may include a first roller operably coupled to the body and a second roller operably coupled to a second roller latch assembly and a second inner body, the first latch receiver assembly and the second latch receiver assembly operably coupled to the outer body, the first roller latch assembly configured to selectively latch or unlatch with the first latch receiver assembly, the second roller latch assembly configured to selectively latch or unlatch with the second latch receiver assembly, the outer body selectively operably coupled to the first inner body and the second inner body by a latch shaft assembly, and the first inner body and the second inner body configured to selectively rotate independently of one another relative to the outer body.

[0012] The variable valve lift rocker arm assembly can include a first roller latch assembly having a first latch pin and a second roller latch assembly having a second latch pin, the first roller latch assembly configured to latch or unlatch with the first latch receiver assembly via the first latch pin and the second roller latch assembly configured to latch or unlatch with the second latch receiver assembly via the second latch pin.

[0013] The variable valve lift rocker arm assembly may include a latch shaft assembly further comprising a third latch receiver assembly and a fourth latch receiver assembly, the third latch receiver assembly and the fourth latch receiver assembly being operably coupled within the outer body, the second latch roller assembly configured to selectively latch or unlatch with the third latch receiver assembly, and the first latch roller assembly configured to selectively latch or unlatch with the fourth latch receiver assembly.

[0014] The variable valve lift rocker arm assembly may include a first roller latch assembly comprising a first latch pin and a fourth latch pin, a second roller latch assembly comprising a second latch pin and a third latch pin, the first latch receiver assembly configured to engage or disengage with the first latch pin, the third latch receiver assembly configured to engage or disengage with the third latch pin, the second latch receiver assembly configured to engage or disengage with the second latch pin, and the fourth latch receiver assembly configured to engage or disengage with the fourth latch pin.

[0015] The variable valve lift rocker arm assembly may include a first roller latch assembly and a second roller latch assembly that are independently latched and unlatched.

[0016] The variable valve lift rocker arm assembly can include a first lost motion spring operably coupled to the outer body and the first inner body, and a second lost motion spring operably coupled to the outer body and the second inner body.

[0017] The variable valve lift rocker arm assembly can include a first roller that is coaxial with a second roller when both the first roller and the second roller are in a cam base circle position.

[0018] The variable valve lift rocker arm assembly may include an outer body having a latch shaft assembly, an outer axial bore for receiving at least one valve end, an outer bore shaft, and the latch shaft assembly, an inner body having an inner axial bore for receiving the inner bore shaft, and a roller operably coupled to the latch shaft assembly and the inner body, the outer body being operably coupled to the inner body by the latch shaft assembly, the outer body being configured to selectively rotate relative to the inner body via the rocker shaft, the latch shaft assembly comprising a roller latch assembly operably coupled to the inner body and the roller, and a first latch receiver assembly operably coupled to the outer body.

[0019] The variable valve lift rocker arm assembly can include a roller latch assembly including a first latch pin configured to engage a first latch receiver assembly to move between a latched position in which the first latch pin engages the first latch receiver assembly to lock relative rotation between the inner body and the outer body, and an unlatched position in which the first latch pin disengages from the first latch receiver assembly to allow relative rotation between the inner body and the outer body.

[0020] The variable valve lift rocker arm assembly may include a roller latch assembly including a second latch pin and an outer body including a second latch receiver assembly, the first and second latch pins configured to engage the first and second latch receiver assemblies in a latched position, where the first latch pin engages the first latch receiver assembly and the second latch pin engages the second latch receiver assembly to lock relative rotation between the inner body and the outer body, and the first and second latch pins configured to engage the first and second latch receiver assemblies in an unlatched position, where the first latch pin disengages from the first latch receiver assembly and the second latch pin disengages from the second latch receiver assembly to allow relative rotation between the inner body and the outer body.

[0021] Additional objectives and advantages will be set forth in part in the specification which follows, and in part will be obvious from the specification or may be learned by the practice of the present disclosure. The objectives and advantages will also be realized and obtained by means of the elements and combinations particularly pointed out in the appended claims.

[0022] It is to be understood that both the foregoing general description and the following detailed description are merely exemplary and explanatory of the invention, as claimed, and are not restrictive. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a perspective view of a variable valve lift rocker arm assembly with roller deactivation. [Diagram 2] FIG. 1 is a cutaway perspective view of a variable valve lift rocker arm assembly with roller deactivation. [Diagram 3]FIG. 3 is a cutaway side view of a variable valve lift rocker arm assembly with roller deactivation at the cam base circle position, taken from a generally similar orientation to FIG. 2 . [Figure 4] FIG. 3 is a cutaway side view of a variable valve lift rocker arm assembly with roller deactivation at cam lift position, with the roller offset and lost motion spring activated, taken from a generally similar orientation to FIG. 2 . [Diagram 5] FIG. 13 is another perspective view of the variable valve lift rocker arm assembly with roller deactivation at the cam base circle position. [Figure 6] FIG. 6 is a cutaway side view of the variable valve lift rocker arm assembly with roller deactivation in unlatched mode, taken generally from line 6 in FIG. 5 . [Figure 7] FIG. 6 is a cutaway side view of the variable valve lift rocker arm assembly with roller deactivation in unlatched mode with the offset roller in a cam lift position, taken generally from line 6-6 in FIG. 5 . [Figure 8] FIG. 6 is a cutaway side view of the variable valve lift rocker arm assembly with roller deactivation in latched mode at the cam base circle position, taken generally from line 6 in FIG. 5 . [Figure 9] FIG. 1 is a perspective view of a variable valve lift rocker arm assembly with roller deactivation, in which two rollers can be deactivated. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] FIG. 1 illustrates a perspective view of a variable valve lift rocker arm assembly 1 with roller actuation deactivation for an internal combustion engine, according to an exemplary embodiment of the present disclosure. The rocker arm assembly 1 can be configured to support a variety of variable valve actuation mechanisms in an internal combustion engine. Additionally, while the disclosed embodiments may be particularly beneficial for enabling variable valve lift in Type III (center pivot) valve trains, the present disclosure may be applied to or used in conjunction with many other types of valve train systems and configurations that include one or more cam actuated rollers. Similarly, while the disclosed embodiments may be particularly beneficial for heavy vehicles and machines, the present disclosure may be applied to or used in conjunction with many other types of vehicles and applications.

[0025] As seen in FIG. 1, the outer body 11 can include at least one valve end. The outer body is shown with two valve ends, a first valve end 12 and a second valve end 13 on the valve side of the outer body 11. The first valve end 12 and the second valve end 13 include bore holes (not shown) through which, in this embodiment, a threaded rod 14 is coupled. The threaded rod 14 is secured by a nut 15. An elephant foot 16 is coupled to the threaded rod 14 for direct or indirect connection with a valve stem or other structure associated with the valve. The bore holes of the first valve end 12 and the second valve end 13 can accommodate other components instead of or in addition to the threaded rod 14, nut 15, and elephant foot 16. For example, a spigot, a lash adjuster, an actuatable capsule, or a piston, among other options, can be components within the bore.

[0026] The outer body 11 includes an outer shaft bore 17 that may be configured to receive a rocker shaft 18. The rocker shaft 18 may be replaced by a pivot shaft or other suitable structure. As an option, bushings may be inserted into the outer shaft bore 17 and the inner shaft bore 31 to surround the rocker shaft 18. The bushings may be attached to the rocker shaft 18. The rocker shaft 18 may include fluid galleries to provide lubrication or control fluid to one or both of the first and second valve ends 12, 13 and the first and second actuation ports 74, 75. The outer body 11, 901 may be drilled or otherwise formed such that control fluid may connect from the outer shaft bore to the first and second actuation ports 74, 75. A fluid pathway may be similarly formed from the outer shaft bore to the valve ends, among other options.

[0027] The outer body 11 further comprises at least three cam ends, a first cam end 19 , a second cam end 20 and a third cam end 21 , which house an inner body 22 , a primary roller 23 and a secondary roller 24 .

[0028] The inner body 22, discussed further in a later section, is the interface between the secondary roller 24 and the outer body 11 and includes an inner shaft bore 31 configured to receive the rocker shaft 18 and an inner axial bore 32 configured to receive the latch shaft assembly 30, discussed below. The inner body 11 may include a "C" shape to receive the secondary roller 24. A portion of the inner body 11, such as the inner lost motion spring retainer 28, may be joined to the inner body arms 221, 222. The inner body arms 221, 222 may be drilled such that the inner shaft bore 31 and the inner axial bore 29 are formed on either side of the "C" shape of the inner body 22. For example, the rocker shaft 18 or bushing may be seated within the corresponding drillings that form the inner shaft bore 31. A shaft bushing 34 may span the inner axial bore 32. The primary roller 23 and secondary roller 24 may be configured to interface with a camshaft lobe of a valve train assembly.

[0029] A lost motion spring 25 is positioned between the outer body 11 and the inner body 2 and may have a first end connected to the inner body 22 and a second end connected to the outer body 11. In this embodiment, the lost motion spring 25 is secured to the outer body 11 by an outer lost motion spring retainer 26, which is further secured to the outer body 11 via an outer lost motion spring retainer post 27. Other fasteners such as screws, nuts, rivets, among other options, may be used to secure the lost motion spring retainer 25 to the outer body 11. The lost motion spring 25 may be secured to the inner body 22 by an inner lost motion spring retainer 28. Other fasteners such as a piston assembly may be used. Other sources of lost motion spring tension may also be used.

[0030] The latch shaft assembly 30 may be installed in an axle bore 29 that extends through the first cam end 19, the second cam end 20, and the third cam end 21 of the outer body 11, as well as the inner body 22, the main roller 23, and the secondary roller 24. The axle bore 29 may be known as an outer axle bore 291 when it extends through the outer body 11. Additional portions of the axle bore 29 may include second and third outer axle bores 292, 293 formed in the second cam end 20 and the third cam end 21, respectively. The axle bore 29 is configured to receive the latch shaft assembly 30. The latch shaft assembly 30, like the axle bore 29, extends through the first cam end 19, the second cam end 20, and the third cam end 21 of the outer body 11, as well as the inner body 22, the main roller 23, and the secondary roller 24. The latch shaft assembly 30, which includes at least one latch mechanism, is discussed further below.

[0031] FIG. 2 shows a cutaway perspective view of a variable valve lift rocker arm assembly with roller deactivation.

[0032] As shown in Figure 2, the outer body 11 includes an outer shaft bore 17 that can receive an optional shaft bushing or rocker shaft 18. The rocker shaft 18 also passes through the inner body 22, allowing the outer body 11 and the inner body 22 to be rotatably coupled. For manufacturing purposes, the rocker shaft 18 does not need to be included in the rocker arm assembly 1 until it is installed on the valve train. An optional bushing can be installed in the rocker arm assembly 1 to stabilize the inner body 22 relative to the outer body 11 prior to installation in the valve train.

[0033] FIG. 3 is a cutaway side view of a variable valve lift rocker arm assembly with roller deactivation at the cam base circle position, taken from generally the same direction as FIG. 2.

[0034] Generally, a cam attached to a camshaft spins and as the cam turns it exerts pressure either directly or indirectly on a roller. The profile of the cam may include lobes that correspond to valve lift events. The cam base circle position corresponds to a portion of the cam profile where no lobe is present and the pressure exerted directly or indirectly by the cam on the roller is minimal. The cam lift mode position corresponds to a portion of the cam profile where a cam lobe is present and the pressure exerted directly or indirectly by the cam on the roller is greater than the pressure exerted by the cam at the cam base circle position, causing the valve end to move one or more associated valves.

[0035] 3, the inner shaft bore 31 is shown in cross section through the inner body 22. The rocker shaft 18 passes through the inner shaft bore 31. The rocker shaft 18 traverses the outer body 11 and the inner body 22, connecting the outer body 11 to the inner body 22 and allowing the inner body 22 to pivot relative to the outer body 11 and vice versa.

[0036] The latch shaft assembly 30 passes through the primary and secondary rollers 23 , 24 , outer body 11 , and inner body 22 via shaft bore 29 .

[0037] 3, 5, 6, 8, and 9 show the rocker arm assembly 1 in the cam base circle position where there is no valve lift force applied by the camshaft lobes to the secondary roller 24. In FIGS. 4 and 7, the camshaft lobes apply a valve lift force that is transmitted to the valve ends 12 and 13 through the inner body 22 and the outer body 11. A lost motion spring 25 acting on the inner body 22 positions the secondary roller 24 to be on the same axis as the primary roller 23 in FIG. 3, so that the two rollers 23, 24 are aligned on the same axis. Although the secondary roller 24 is aligned on the same axis as the primary roller 23 at the cam base circle position, other configurations can include the secondary roller 24 being offset from the primary roller 23 at the cam base circle position.

[0038] FIG. 4 shows a cutaway side view of a variable valve lift rocker arm assembly with roller deactivation in a cam lift mode position where the rollers are offset, taken from generally the same direction as FIG. 2.

[0039] The variable valve lift rocker arm assembly 1 with the secondary roller 24 in unlatched mode, as shown in Figure 4. In Figure 4, the camshaft lobe is driving the secondary roller 24 and inner body 22 upward in the cam lift mode position. Thus, the secondary roller 24 and inner body 22 pivot relative to the outer body 11 along an axis (facing in and out of the page) defined by the inner shaft bore 31 and the rocker shaft 18.

[0040] This motion also compresses the lost motion spring 25 between the outer body 11 and the inner body 22, so that part of the force from the camshaft lobe and part of the resulting motion is absorbed by the lost motion spring 25. If the lost motion spring 25 absorbs all of the force, the secondary roller 24 is considered to be completely deactivated. However, it is also possible that part of the force from the camshaft lobe motion is transmitted to the valve ends 12 and / or 13 due to a partially deactivated variable valve lift function. Note that even though the secondary roller 24 is movable relative to the outer body 11, the primary roller 23 remains fixed relative to the outer body 11. As the cam returns to the cam base circle position, the force from the camshaft lobe subsides and the lost motion spring 25 drives the inner body 22 and secondary roller 24 back to the approximate configuration shown in FIG. 3.

[0041] FIG. 5 is a perspective view of a variable valve lift rocker arm assembly with roller deactivation from a different angle than previously illustrated.

[0042] 5, the rocker shaft 18 can be configured to pass completely through the outer body 11 and the inner body 22. The latch shaft assembly 30 can pass completely through the outer body 11, through the first cam end 19, the second cam end 20, and the third cam end 21, as well as the inner body 22, the primary roller 23, and the secondary roller 24.

[0043] In Fig. 5, the secondary roller 24 can be in a latched state in Fig. 8 or an unlatched state in Fig. 6. When the secondary roller 24 is latched as in Fig. 8, the secondary roller 24 and the inner body 22 remain fixed relative to the outer body 11 and the inner body 22 cannot pivot relative to the outer body 11 and vice versa. Any force and resulting motion from the camshaft lobes is transferred to the valve ends 12 and / or 13 of the outer body 11. The lost motion spring 25 remains uncompressed. Note that the primary roller 23 is fixed relative to the outer body 11, as is the secondary roller 24.

[0044] Figure 6 is a cutaway side view of the variable valve lift rocker arm assembly 1 and roller latch assembly 61 with roller deactivation in unlatched mode, taken generally from line 6-6 in Figure 5. Figure 7 is a cutaway side view of the variable valve lift rocker arm assembly 1 and roller latch assembly 61 with roller deactivation in unlatched mode, with the secondary roller 24 offset from the cam lobe lift. Figure 8 is a cutaway side view of the variable valve lift rocker arm assembly 1 with the secondary roller 24 in latched mode.

[0045] An axial bore 29 extends through the outer body 11 and the primary roller 23. An inner axial bore 32 extends through the inner body 22 and the secondary roller 24. The axial bore 29 and the inner axial bore 32 are configured to receive a latch shaft assembly 30. The latch shaft assembly 30 forms an axis about which the primary roller 23 and the secondary roller 24 can roll, but also includes at least one roller latch assembly 61 and one first latch receiver assembly 62, although an optional second latch receiver assembly 63 is shown here. The roller latch assembly 61 is operably coupled to the inner body 22 and the secondary roller 24. The first latch receiver assembly 62 and the second latch receiver assembly 63 are operably coupled to the outer body 11. One latch receiver assembly can be coupled to the primary roller 23. Alternatively, the primary roller 23 can be coupled to the outer body 11 via a separate mechanism. At least one latch receiver assembly should be coupled to the outer body 11.

[0046] The roller latch assembly 61 includes a latch pin spring 64, a first latch pin 65, and a second latch pin 66. The roller latch assembly 61 can be seated in a shaft bushing 34. The shaft bushing 34 can be inserted into the inner axial bore 32 of the inner body arm 221, 222, or the shaft bushing 34 can be integrally formed with the inner body arm 221, 222. Although two latch pins are shown, it is possible to use only one latch pin and one latch receiver assembly. The second latch pin can be converted to a blind bore or other spring seating surface for the latch pin spring 64, such as a plug or circlip. The secondary roller 24 is attached to the shaft bushing 34. The roller latch assembly 61 can be in conjunction with at least a first latch receiver assembly 62, as described below.

[0047] A spacer or travel limit may be included within the roller latch assembly 61. The first and second latch pins 65, 66 are shown as hollow pistons that may receive the latch pin spring 64. The first and second latch pins 65, 66 may comprise body portions that may be slidable within the shaft bushing 34. The body portions may extend from the roller latch assembly 61 and seat within the first and second latch receiver assemblies 62, 63. The first and second latch pins 65, 66 may be slidable within the first and second latch receiver assemblies 62, 63 to enable the latched mode. Each end of the latch pin spring 64 is biased against and effectively captivates each of the first and second latch pins 65, 66. Alternatives may include a split wall and two latch pin springs 64. When only one latch pin is present, one end of the latch pin spring 64 is biased against the first latch pin 65 while the other end of the latch pin spring 64 is otherwise biased against the interior of the roller latch assembly 61. The roller latch assembly 61 may also include mechanisms for anchoring the first latch pin 65 and second latch pin 66 to the latch guide rod or interior of the roller latch assembly 61 for purposes such as travel limiting, force distribution, among others.

[0048] The first latch receiver assembly 62 includes a first piston spring 67, a first piston 69, and a first spring chamber 72. The second latch receiver 63 includes a second piston spring 68, a second piston 70, a guide rod 71, and a second spring chamber 73. The first spring chamber 72 can be formed within the first latch receiver assembly 62. A mating retainer 671, such as a cap or cage, can secure the first piston spring 67 in place. The second spring chamber 73 can also be formed within the second latch receiver assembly 63. The first spring chamber 72 and the spring pressure chamber 73 can be sized such that the first piston spring 67 and the second piston spring 68 can bias the first piston 69 and the second piston 70 against the roller latch assembly 61. The spring forces can be balanced to bias the roller latch assembly 61 in either the latched or unlatched mode as a design choice. As shown, the spring forces between the latch pin spring 64, the first piston spring 67, and the second piston spring 68 are balanced so that the secondary roller 24 is in the default unlatched mode. The first and second latch pins 65, 66 are unlatched from the receiving cups 621, 631. A deactivation sequence can be followed upon start-up of the associated vehicle or machine.

[0049] A first pressure chamber 78 is operably coupled to a first actuation port 74 through which control fluid can enter the first pressure chamber 78. When the control fluid is depressurized, the control fluid can exit the first pressure chamber 78 via a leak-down path. Optionally, a bleed port can be included in the retainer 671. A second pressure chamber 779 is operably coupled to a second actuation port 75. An optional bleed port 76 and a lubrication port 77 can be included. The second actuation port 75 allows the control fluid to enter the second pressure chamber 79. When the control fluid is depressurized, the control fluid can exit the second pressure chamber 79 via the bleed port 76 and the leak-down path. The lubrication port 77 can allow the flow of lubrication fluid main roller 23. The control fluid draws the first and second pistons 69, 70 into the first and second latch receiver assemblies 62, 63. The first and second latch pins 65, 66 can then be forced outward to latch into the receiving cups 621, 631 for the latched mode. If a biased latched mode is desired, the spring chambers 72, 73 and pressure chambers 78, 79 can be reversed to move the first and second actuation ports 74, 75 to feed the spring chambers 72, 73 and push the first and second latch pistons 69, 70.

[0050] A guide rod 71 can be seated within the second latch receiver assembly 63. The guide rod 71 can be configured to provide a portion of the second spring chamber 73. The guide rod 71 can be secured in place by a retainer, such as a snap ring, washer, plug, stake, or the like. A second piston 70 can be slidably mounted within the second latch receiver assembly 63. One end of a second piston spring 68 can be biased against the guide rod 71, while the other end of the second piston spring 68 can be biased against the second piston 70. The second piston spring 68 can counter a spring force from the latch pin spring 64 imparted by the second latch pin 66.

[0051] For shorter latch receivers, the guide rod 71 can be eliminated, for example, with the first piston 69 slidably mounted within the first latch receiver assembly 62. A first end of the first piston spring 67 can seat within the first latch receiver assembly 62 and a second end of the first piston spring 67 can seat against the first piston 69.

[0052] Alternatively, the first latch receiver assembly 62 may also include a guide rod with the first piston 69 slidably mounted on the guide rod. A first end of the first piston spring 67 may be affixed to the guide rod while the other end of the first piston spring 67 may seat against the first piston 69.

[0053] Latch receiver configurations with and without guide rods 71 ​​may be combined, for example, one receiver with a guide rod and another without, as shown above. Alternatively, a configuration could include two receivers, each with a guide rod, or two receivers both without a guide rod. Additionally, the roller latch assembly 61 could be configured to operate with only a single latch pin and / or only a single latch receiver, rather than two each.

[0054] The first piston spring 67 and the second piston spring 68 can exert a greater force than the latch pin spring 64. As seen in FIG. 6, when the roller latch assembly 61 is in the unlatched mode, the control fluid in the pressure chambers 78, 79 is at a relatively low pressure, and the first piston spring 67 and the second piston spring 68 push the first piston 69 and the second piston 70, which in turn push the first latch pin 65 and the second latch pin 66, thereby compressing the latch pin spring 64, so that the first latch pin 65 and the second latch pin 66 move away from the first latch receiver assembly 62 and the second latch receiver assembly 63. This allows the roller latch assembly 61, together with the secondary roller 24 and the inner body 22, to swing freely from the outer body 11 as seen in FIG. 7, and the secondary roller 24 and the inner body 22 to pivot relative to the outer body 11. The force from the cam lobe may be transferred directly or indirectly through the secondary roller 24 , thereby compressing the lost motion spring 25 .

[0055] As shown in FIG. 8, the roller latch assembly 61 is in latch mode. Tension from the lost motion spring 25 can place the roller latch assembly 61 in alignment with the first and second latch receiver assemblies 62, 63, such that the first and second latch pins 65, 66 of the roller latch assembly 61 can engage with the receiving cups 621, 631 of the first and second latch receiver assemblies 62, 63. In the first and second pressure chambers 78, 79, pressurized control fluid is directed to the first and second pistons 69, 70. This overcomes the spring force of the first and second piston springs 67, 68, allowing the latch pin spring 64 to extend, latching the first and second latch pins 65, 66 into the receiving cups 621, 631 of the first and second latch receiver assemblies 62, 63.

[0056] Although this embodiment details a roller latch assembly 61 capable of latching and unlatching only the secondary roller 24, the mechanism of the roller latch 61 can be easily modified and additional roller latch assemblies can be configured to accommodate latching and unlatching of additional rollers.

[0057] 9 is a perspective view of a variable valve lift rocker arm assembly with roller deactivation, where two rollers can be deactivated. The first latch receiver assembly 62 is mirror-image replicated about the split 921, and the first latch receiver assembly thus replicated is distal to the split 921. The second latch receiver assembly 63 can be mirror-image replicated without the guide rod 71, and can be proximal to the split 921.

[0058] As shown in FIG. 9, the outer body 901 includes a first valve end 902 and a second valve end 903 on the valve side of the outer body 901. Rocker shafts or bushings can be configured as described above to secure the outer body 901 and the inner bodies 906, 907 for rotation and valve actuation modes. A first inner shaft bore can extend through the first inner body 906 and a second inner shaft bore can extend through the second inner body 907. The first inner shaft bore and the second inner shaft bore can be configured to receive a rocker shaft, bushing, or pivot axle. The first inner body 906 and the second inner body 907 are rotatably attached to the outer body 901 by the rocker shaft, bushing, or pivot axle.

[0059] The cam side of the rocker arm assembly 1 includes a secondary roller 904 and a primary roller 905. The secondary roller 904 and the primary roller 905 are mounted to a first inner body 906 and a second inner body 907, respectively. A latch shaft assembly 908 can extend through an outer shaft bore, a first inner shaft bore on the first inner body 906, and a second inner shaft bore on the second inner body 907, which are configured to receive the latch shaft assembly 908. The outer shaft bore, the first inner shaft bore, and the second inner shaft bore, and the latch shaft 908 extend through a first cam end 909, a second cam end 910, and a third cam end 911 of the outer body 901, the first inner body 906, the second inner body 907, the secondary roller 904, and the primary roller 905.

[0060] The latch shaft assembly 908 includes a first latch receiver assembly 916, a first roller latch assembly, a second latch receiver assembly 917, a second roller latch assembly, a fourth latch receiver assembly 919, and a third latch receiver assembly 918. The first to fourth latch receiver assemblies are fluidly controlled to selectively engage or disengage the first to fourth latch pins with corresponding receiver cups in the first to fourth latch receiver assemblies. The first latch receiver assembly 916 is similar in seating and operation to the first latch receiver assembly 62 of FIGS. 6-8. The second latch receiver assembly 917 is similar in seating and operation to the second latch receiver assembly 63 of FIGS. 6-8, but does not have a guide rod 71. The second latch receiver assembly 917 and the fourth latch receiver assembly 919 can be separated by a split 920. The third latch receiver assembly 918 is a mirror image of the first latch receiver assembly 916, while the fourth latch receiver assembly 919 is a mirror image of the second latch receiver assembly 917. Although the latch receivers are listed first through fourth herein, they are numbered in the claims in the order in which they are introduced in the claims.

[0061] Both the first roller latch assembly and the second roller latch assembly are similar in seating and operation to roller latch assembly 61 of Figures 6-8. As taught above with respect to Figures 6-8, the first roller latch assembly seats within secondary roller 904 and the second roller latch assembly seats within primary roller 905.

[0062] The first inner body 906 and the second inner body 907 may be operatively connected to the outer body 901 by a first lost motion spring 912 and a second lost motion spring 913. One end of each of the first lost motion spring 912 and the second lost motion spring 913 may be connected to the outer body 901 by an outer lost motion spring retainer 914. The outer lost motion spring retainer 914 may then be attached to an outer lost motion spring retainer post 915 of the outer body 901. The other end of each of the first lost motion spring 912 and the second lost motion spring 913 may be connected to the first inner body 906 and the second inner body 907, respectively, via the inner lost motion spring retainer.

[0063] In this embodiment, either the primary or secondary rollers can be latched or unlatched, either alone or together. This allows for four separate lift combinations including the primary roller 905 latched and the secondary roller 904 unlatched, the primary roller 905 unlatched and the secondary roller 904 latched, both the primary roller 905 and secondary roller 904 latched thereby allowing a "double lift" or "ghost lift", or both the primary roller 905 and secondary roller 904 unlatched to allow for cylinder deactivation.

[0064] While the above embodiments describe an outer body 22, 901 having a first valve end 12, 902 and a second valve end 13, 903, the embodiments may be modified to allow for fewer or additional valve ends as may be required by design parameters. Similarly, while the above embodiments describe a rocker arm assembly 1 having a primary roller 23, 905 and a secondary roller 24, 904, the rocker arm assembly 1 may be modified to allow for fewer or additional rollers, and any combination of rollers may be latchable and unlatched.

[0065] Other implementations will be apparent to those skilled in the art from consideration of the specification and practice of the examples disclosed herein.

[0066] In view of the above, it can be said that a variable valve lift rocker arm assembly can include a latch shaft assembly comprising a roller latch assembly and a first latch receiver assembly, an outer body configured to rotate about the rocker shaft, the outer body comprising at least a valve end and a cam end comprising an outer axial bore for seating the first latch receiver assembly of the latch shaft assembly, an inner body configured to rotate about the rocker shaft, the inner body comprising an inner axial bore configured to seat the roller latch assembly of the latch shaft assembly, a primary roller operably coupled to the outer body, and a secondary roller operably coupled to the inner body, wherein the roller latch assembly and the first latch receiver assembly are configured to selectively operably couple the outer body to the inner body.

[0067] The variable valve lift rocker arm assembly may include a roller latch assembly seated within a shaft bushing within a secondary roller.

[0068] The variable valve lift rocker arm assembly can include a roller latch assembly including a first latch pin configured to move between a latched position in which the first latch pin engages the first latch receiver assembly to lock relative rotation between the inner body and the outer body and an unlatched position in which the first latch pin disengages from the first latch receiver assembly to allow relative rotation between the inner body and the outer body.

[0069] The variable valve lift rocker arm assembly can include a roller latch assembly further comprising a second latch pin, the latch shaft assembly further comprising a second latch receiver assembly within the outer body, the second latch pin configured to engage with the second latch receiver assembly in the latched position and the second latch pin configured to disengage from the second latch receiver assembly in the unlatched position.

[0070] The variable valve lift rocker arm assembly can include a first latch receiver configured to selectively press against the roller latch assembly to selectively unlatch the inner body from the outer body.

[0071] The variable valve lift rocker arm assembly includes a latch shaft assembly including a first roller latch assembly, a second roller latch assembly, a first latch receiver assembly, and a second latch receiver assembly; an outer body including at least one valve end, an outer bore shaft, and an axial bore for receiving a first portion of the latch shaft assembly; a first inner body including a first inner bore shaft and a first inner axial bore for receiving a second portion of the latch shaft assembly; a second inner body including a second inner bore shaft and a second inner axial bore for receiving a third portion of the latch shaft assembly; and a first roller latch assembly and a first inner latch assembly. The latch shaft assembly may include a first roller operably coupled to the body and a second roller operably coupled to a second roller latch assembly and a second inner body, the first latch receiver assembly and the second latch receiver assembly operably coupled to the outer body, the first roller latch assembly configured to selectively latch or unlatch with the first latch receiver assembly, the second roller latch assembly configured to selectively latch or unlatch with the second latch receiver assembly, the outer body selectively operably coupled to the first inner body and the second inner body by a latch shaft assembly, and the first inner body and the second inner body configured to selectively rotate independently of one another relative to the outer body.

[0072] The variable valve lift rocker arm assembly can include a first roller latch assembly having a first latch pin and a second roller latch assembly having a second latch pin, the first roller latch assembly configured to latch or unlatch with the first latch receiver assembly via the first latch pin and the second roller latch assembly configured to latch or unlatch with the second latch receiver assembly via the second latch pin.

[0073] The variable valve lift rocker arm assembly may include a latch shaft assembly further comprising a third latch receiver assembly and a fourth latch receiver assembly, the third latch receiver assembly and the fourth latch receiver assembly being operably coupled within the outer body, the second latch roller assembly configured to selectively latch or unlatch with the third latch receiver assembly, and the first latch roller assembly configured to selectively latch or unlatch with the fourth latch receiver assembly.

[0074] The variable valve lift rocker arm assembly may include a first roller latch assembly comprising a first latch pin and a fourth latch pin, a second roller latch assembly comprising a second latch pin and a third latch pin, the first latch receiver assembly configured to engage or disengage with the first latch pin, the third latch receiver assembly configured to engage or disengage with the third latch pin, the second latch receiver assembly configured to engage or disengage with the second latch pin, and the fourth latch receiver assembly configured to engage or disengage with the fourth latch pin.

[0075] The variable valve lift rocker arm assembly may include a first roller latch assembly and a second roller latch assembly that are independently latched and unlatched.

[0076] The variable valve lift rocker arm assembly can include a first lost motion spring operably coupled to the outer body and the first inner body, and a second lost motion spring operably coupled to the outer body and the second inner body.

[0077] The variable valve lift rocker arm assembly can include a first roller that is coaxial with a second roller when both the first roller and the second roller are in a cam base circle position.

[0078] The variable valve lift rocker arm assembly may include an outer body having a latch shaft assembly, an outer axial bore for receiving at least one valve end, an outer bore shaft, and the latch shaft assembly, an inner body having an inner axial bore for receiving the inner bore shaft, and a roller operably coupled to the latch shaft assembly and the inner body, the outer body being operably coupled to the inner body by the latch shaft assembly, the outer body being configured to selectively rotate relative to the inner body via the rocker shaft, the latch shaft assembly comprising a roller latch assembly operably coupled to the inner body and the roller, and a first latch receiver assembly operably coupled to the outer body.

[0079] The variable valve lift rocker arm assembly can include a roller latch assembly including a first latch pin configured to engage a first latch receiver assembly to move between a latched position in which the first latch pin engages the first latch receiver assembly to lock relative rotation between the inner body and the outer body, and an unlatched position in which the first latch pin disengages from the first latch receiver assembly to allow relative rotation between the inner body and the outer body.

[0080] The variable valve lift rocker arm assembly may include a roller latch assembly including a second latch pin and an outer body including a second latch receiver assembly, the first and second latch pins configured to engage the first and second latch receiver assemblies in a latched position, where the first latch pin engages the first latch receiver assembly and the second latch pin engages the second latch receiver assembly to lock relative rotation between the inner body and the outer body, and the first and second latch pins configured to engage the first and second latch receiver assemblies in an unlatched position, where the first latch pin disengages from the first latch receiver assembly and the second latch pin disengages from the second latch receiver assembly to allow relative rotation between the inner body and the outer body.

Claims

1. 1. A variable valve lift rocker arm assembly, comprising: a latch shaft assembly including a roller latch assembly and a first latch receiver assembly; an outer body configured to rotate about a rocker shaft, the outer body comprising one or more valve ends and a plurality of cam ends forming a unitary structure rotatably coupled with the one or more valve ends, the plurality of cam ends comprising an outer shaft bore for seating the first latch receiver assembly of the latch shaft assembly; an inner body configured to rotate about the rocker shaft, the inner body including an inner shaft bore configured to seat the roller latch assembly of the latch shaft assembly; a main roller operably coupled to the outer body; a secondary roller operably coupled to the inner body; the roller latch assembly and the first latch receiver assembly are configured to selectively operably couple the outer body to the inner body; A variable valve lift rocker arm assembly, wherein the inner body is axially enclosed and supported between the cam ends of the outer body.

2. The variable valve lift rocker arm assembly of claim 1 , wherein said roller latch assembly seats within a shaft bushing within said secondary roller.

3. 3. The variable valve lift rocker arm assembly of claim 1 or 2, wherein the roller latch assembly comprises a first latch pin configured to move between a latched position in which the first latch pin engages the first latch receiver assembly to lock relative rotation between the inner body and the outer body, and an unlatched position in which the first latch pin disengages from the first latch receiver assembly to allow relative rotation between the inner body and the outer body.

4. the roller latch assembly further comprising a second latch pin; the latch shaft assembly further comprising a second latch receiver assembly within the outer body; the second latch pin is configured to engage the second latch receiver assembly in the latched position; The variable valve lift rocker arm assembly of claim 3 , wherein said second latch pin is configured to disengage from said second latch receiver assembly in said unlatched position.

5. 5. The variable valve lift rocker arm assembly of claim 1, wherein the first latch receiver assembly is configured to selectively press against the roller latch assembly to selectively unlatch the inner body from the outer body.

6. 1. A variable valve lift rocker arm assembly, comprising: a latch shaft assembly comprising a first roller latch assembly, a second roller latch assembly, a first latch receiver assembly, and a second latch receiver assembly; An outer body, at least one valve end; an outer bore shaft; an axial bore for receiving a first portion of the latch shaft assembly; and A first inner body, a first inner bore shaft; a first inner body having a first inner shaft bore for receiving a second portion of the latch shaft assembly; A second inner body, a second inner bore shaft; a second inner body comprising: a second inner shaft bore for receiving a third portion of the latch shaft assembly; a first roller operably coupled to the first roller latch assembly and the first inner body; a second roller operably coupled to the second roller latch assembly and the second inner body; the first latch receiver assembly and the second latch receiver assembly are operably coupled to the outer body; the first roller latch assembly is configured to selectively latch and unlatch with the first latch receiver assembly; the second roller latch assembly is configured to selectively latch and unlatch with the second latch receiver assembly; the outer body being selectively operably coupled to the first inner body and the second inner body by the latch shaft assembly; A variable valve lift rocker arm assembly, wherein the first inner body and the second inner body are configured to selectively rotate independently of one another relative to the outer body.

7. the first roller latch assembly comprising a first latch pin; the second roller latch assembly includes a second latch pin; the first roller latch assembly is configured to latch or unlatch with the first latch receiver assembly via the first latch pin; the second roller latch assembly is configured to latch or unlatch with the second latch receiver assembly via the second latch pin; 7. The variable valve lift rocker arm assembly of claim 6.

8. the latch shaft assembly further comprises a third latch receiver assembly and a fourth latch receiver assembly; the third latch receiver assembly and the fourth latch receiver assembly are operably coupled within the outer body; the second latch receiver assembly is configured to selectively latch or unlatch with the third latch receiver assembly; the first latch receiver assembly is configured to selectively latch or unlatch with the fourth latch receiver assembly; 7. The variable valve lift rocker arm assembly of claim 6.

9. the first roller latch assembly comprises a first latch pin and a fourth latch pin; the second roller latch assembly comprises a second latch pin and a third latch pin; the first latch receiver assembly is configured to engage and disengage with the first latch pin; the third latch receiver assembly is configured to engage and disengage with the third latch pin; the second latch receiver assembly is configured to engage and disengage with the second latch pin; the fourth latch receiver assembly is configured to engage and disengage with the fourth latch pin; 9. The variable valve lift rocker arm assembly of claim 8.

10. A variable valve lift rocker arm assembly according to any one of claims 6 to 9, wherein the first roller latch assembly and the second roller latch assembly are independently latched or unlatched.

11. a first lost motion spring operably coupled to the outer body and the first inner body; a second lost motion spring operably coupled to the outer body and the second inner body; The variable valve lift rocker arm assembly of any one of claims 6 to 9, further comprising:

12. 12. A variable valve lift rocker arm assembly as claimed in any one of claims 6 to 11, wherein the first roller is on the same axis as the second roller when both the first roller and the second roller are in a cam base circle position.

13. 1. A variable valve lift rocker arm assembly, comprising: A latch shaft assembly; an outer body including at least one valve end, a plurality of cam ends, an outer bore shaft, and an outer shaft bore for receiving said latch shaft assembly; an inner body including an inner axial bore for receiving an inner bore shaft and the latch shaft assembly, the inner body being axially surrounded and supported between the cam ends of the outer body; a roller operatively coupled to the latch shaft assembly and the inner body; the outer body is operably coupled to the inner body by the latch shaft assembly; the outer body is configured to selectively rotate relative to the inner body via a rocker shaft; the latch shaft assembly comprising a roller latch assembly operably coupled to the inner body and the roller; A variable valve lift rocker arm assembly, wherein a first latch receiver assembly is operably coupled to the outer body.

14. the roller latch assembly comprising a first latch pin; 14. The variable valve lift rocker arm assembly of claim 13, wherein the first latch pin is configured to move between a latched position in which the first latch pin engages the first latch receiver assembly to lock relative rotation between the inner body and the outer body, and an unlatched position in which the first latch pin disengages from the first latch receiver assembly to allow relative rotation between the inner body and the outer body.

15. the roller latch assembly including a second latch pin; the outer body includes a second latch receiver assembly; the first latch pin and the second latch pin are configured to engage the first latch receiver assembly and the second latch receiver assembly in a latched position, wherein the first latch pin engages the first latch receiver assembly and the second latch pin engages the second latch receiver assembly to lock the relative rotation between the inner body and the outer body; 15. The variable valve lift rocker arm assembly of claim 14, wherein the first and second latch pins are configured to engage the first and second latch receiver assemblies in an unlatched position, wherein in the unlatched position, the first latch pin disengages from the first latch receiver assembly and the second latch pin disengages from the second latch receiver assembly to allow relative rotation between the inner body and the outer body.

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