Switchable rocker arms assemblies and methods thereof

Abstract

A rocker arm assembly includes a first body and a second body operatively coupled to the first body, a latch assembly, and a stop mechanism. The latch assembly is operable in a first latch state and a second latch state. The first latch state is configured to prevent a relative motion between the first body and the second body, and the second latch state is configured to permit a relative motion therebetween. The stop mechanism includes a stop bore and a stop pin disposed in the stop bore.

Description

PRIORITY

[0001] This application claims the benefit under 35 U.S.C. § 365(c) of International Patent Application No. PCT / IB2024 / 058057, filed 19 Aug. 2024, which claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Ser. No. 63 / 520,450 , filed 18 Aug. 2023, which is incorporated herein by reference.TECHNICAL FIELD

[0002] This disclosure generally relates to engine valvetrain systems, and more particularly to valvetrains with switchable rocker arms.BACKGROUND

[0003] Switchable rocker arm assemblies may include stop mechanisms to control a range of motion possible between components during operation. Stop mechanisms may include features that necessitate complex, time-consuming, and / or expensive processes to manufacture. For example, considerable precision may be required for mutual alignment, machining, and finishing operations of particular features, such as to meet operational tolerance requirements. Some stop mechanism designs may also be associated with undesirable forces and / or torques acting on parts of the stop mechanism, and / or on interfacing surfaces thereof.SUMMARY OF PARTICULAR EMBODIMENTS

[0004] Features, devices, systems, and methods disclosed with reference to particular embodiments described herein can enable means for establishing and / or maintaining improved switching performance and latch lash in valvetrains with switchable rocker arms. The present disclosure includes strategies, systems, and methods to enable and provide for less stringent manufacturing tolerance requirements, improved ease of manufacturing and assembly, lower cost, and / or improved lash and latching performance over the operational life of the valvetrain components and systems.

[0005] In particular embodiments, a rocker arm assembly is disclosed, including: a first body and a second body operatively coupled to the first body, at least one of the first body or the second body configured to be rotatable about a rocker shaft; a latch assembly operable in a first latch state and a second latch state and including a latch bore passing through at least a portion of each of the first body and the second body, wherein the latch assembly is configured to: operatively couple the first body and the second body to prevent relative motion therebetween in the first latch state, and permit relative motion between the first body and the second body in the second latch state; and a stop mechanism including a stop bore and a stop pin disposed in the stop bore, the stop bore configured to pass through at least a portion of each of the first body and the second body, wherein the stop mechanism is configured to operatively constrain a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0006] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop bore of the stop mechanism includes a first portion associated with the second body, wherein a radius of curvature of the first portion is configured based on a radius of curvature of the stop pin. In particular embodiments, which may combine the features of some or all of the above embodiments, one of the first body or the second body includes a valve portion configured to operatively engage with one or more valves. In particular embodiments, which may combine the features of some or all of the above embodiments, one of the first body or the second body includes a cam portion configured to receive a valve lift profile from a cam.

[0007] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop pin is operatively secured to the first body.

[0008] In particular embodiments, which may combine the features of some or all of the above embodiments, one of the first body or the second body includes a forked portion having a first outer portion and a second outer portion configured to axially enclose and support an inner portion of the other of the first body or the second body.

[0009] In particular embodiments, which may combine the features of some or all of the above embodiments, the latch bore is configured to be disposed in at least a portion of each of the first outer portion, the second outer portion, and the inner portion. In particular embodiments, which may combine the features of some or all of the above embodiments, the latch bore passes through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

[0010] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop pin is operatively secured to the first body or the second body. In particular embodiments, which may combine the features of some or all of the above embodiments, the stop bore is configured to be disposed in at least a portion of each of the first outer portion, the second outer portion, and the inner portion. In particular embodiments, which may combine the features of some or all of the above embodiments, the stop pin is operatively secured to the inner portion and configured to extend into one or both of the first outer portion or the second outer portion.

[0011] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop bore further includes a second portion associated with the second body, the second portion configured to prevent over-travel of the first body or the second body during operation of the rocker arm assembly.

[0012] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop bore passes through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

[0013] In particular embodiments, which may combine the features of some or all of the above embodiments, the rocker arm assembly further includes a lost motion assembly operatively coupled to the first body and the second body and configured to selectively absorb at least a portion of the valve lift profile received from the cam. In particular embodiments, which may combine the features of some or all of the above embodiments, the lost motion assembly absorbing the at least a portion of the valve lift profile is associated with operating the latch assembly in the second latch state.

[0014] In particular embodiments, which may combine the features of some or all of the above embodiments, the lost motion assembly is operable within a range including a collapsed position and an extended position. In particular embodiments, which may combine the features of some or all of the above embodiments, the lost motion assembly includes a lost motion spring, wherein the lost motion spring is configured to bias the lost motion assembly toward the extended position.

[0015] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop mechanism includes a stop surface configured to engage the stop pin to prevent an overextension of the lost motion assembly. In particular embodiments, which may combine the features of some or all of the above embodiments, the latch assembly further includes one or more latch pins, wherein the one or more latch pins are hydraulically or electrically actuated to selectively decouple the first body and the second body.

[0016] In particular embodiments, which may combine the features of some or all of the above embodiments, a method of making a rocker arm assembly is disclosed, the method including: constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation; providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly includes the latch bore; providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly includes the stop bore and a stop pin; and disposing the stop pin in the stop bore and coupling the stop pin to the first body or the second body so that the stop mechanism operatively constrains a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0017] In particular embodiments, which may combine the features of some or all of the above embodiments, the latch bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body. In particular embodiments, which may combine the features of some or all of the above embodiments, the stop bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body.

[0018] In particular embodiments, which may combine the features of some or all of the above embodiments, a valvetrain system is disclosed including: a piston disposed in a cylinder; one or more valves associated with the cylinder; a rocker shaft; and a rocker arm assembly configured to be rotatable about the rocker shaft, including: a first body and a second body operatively coupled to the first body, at least one of the first body or the second body configured to be rotatable about the rocker shaft; a latch assembly operable in a first latch state and a second latch state and including a latch bore passing through at least a portion of each of the first body and the second body, wherein the latch assembly is configured to: operatively couple the first body and the second body to prevent relative motion therebetween in the first latch state, and permit relative motion between the first body and the second body in the second latch state; and a stop mechanism including a stop bore and a stop pin disposed in the stop bore, the stop bore configured to pass through at least a portion of each of the first body and the second body, wherein the stop mechanism is configured to operatively constrain a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0019] In particular embodiments, which may combine the features of some or all of the above embodiments, one of the first body or the second body includes a forked portion having a first outer portion and a second outer portion configured to axially enclose and support an inner portion of the other of the first body or the second body, and wherein one or more of the latch bore or the stop bore is configured to pass through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

[0020] In particular embodiments, which may combine the features of some or all of the above embodiments, a method of making a rocker arm assembly is disclosed comprising: constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation; providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly includes the latch bore; providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly includes the stop bore and a stop pin; and disposing the stop pin in the stop bore and coupling the stop pin to one of the first body or the second body so that the stop mechanism operatively constrains a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0021] In particular embodiments, which may combine the features of some or all of the above embodiments, the latch bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body, and the stop bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body.

[0022] In particular embodiments, which may combine the features of some or all of the above embodiments, a method includes providing a conforming portion associated with the stop bore in the second body such that a radius of curvature of the conforming portion is configured to receive the stop pin, wherein the stop pin is coupled to the first body.

[0023] In particular embodiments, which may combine the features of some or all of the above embodiments, a method of making a rocker arm assembly is disclosed, including: constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation; providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly includes the stop bore and a stop pin, and wherein the stop bore includes a conforming portion associated with the second body such that a radius of curvature of the conforming portion is configured to receive the stop pin; disposing the stop pin in the stop bore and coupling the stop pin to the first body so that the stop mechanism defines a range of relative motion between the first body and the second body; and providing a clearance cut overlapping with at least a portion of the stop bore in the second body, wherein one or more edges of the clearance cut define a limit of allowable travel of the stop pin coupled to the first body during operation of the rocker arm assembly.

[0024] In particular embodiments, which may combine the features of some or all of the above embodiments, a method further includes providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly includes the latch bore.BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be described in greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. Other features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following:

[0026] FIG. 1 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments.

[0027] FIG. 2 illustrates a schematic sectioned top view of a rocker arm assembly, according to particular embodiments.

[0028] FIG. 3 illustrates a schematic partially exploded perspective view of a rocker arm assembly, according to particular embodiments.

[0029] FIG. 4 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments, with an inset depicting particular details of an exemplary stop mechanism.

[0030] FIG. 5A illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments, with an inset depicting particular details of an exemplary stop mechanism.

[0031] FIG. 5B illustrates a schematic side view of a rocker arm assembly, according to particular embodiments.

[0032] FIG. 6 illustrates a schematic sectioned top view of a rocker arm assembly, according to particular embodiments.

[0033] FIG. 7 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments.

[0034] FIG. 8 illustrates a schematic sectioned bottom view of a rocker arm assembly, according to particular embodiments.

[0035] FIG. 9 illustrates a schematic partially exploded perspective view of a rocker arm assembly, according to particular embodiments.DESCRIPTION OF EXAMPLE EMBODIMENTS

[0036] The following examples of certain embodiments are provided to facilitate a better understanding of the present disclosure, and are not to be read to limit or define the scope of the disclosure. In accordance with various embodiments of the present disclosure, various mechanisms, assemblies, arrangements, and methods of operation of switchable rocker arm assemblies are disclosed herein.

[0037] In particular embodiments, an engine may comprise one or more cylinders, wherein each cylinder may be provided with one or more valves, such as for allowing selective fluid exchange. By way of example and not limitation, an engine cylinder may comprise one or more intake valves, and / or one or more exhaust valves. In particular embodiments, the valvetrain of an engine may include devices and systems configured to operate one or more valves of a cylinder. By way of example and not limitation, valve operation parameters such as determination of whether one or more particular valves lift (i.e., open) during operation, an extent of such lift, and / or a timing of such lift relative to other indices of engine operation, such as cylinder motion, may be based on thermodynamic considerations and / or desired modes of operation. By way of example and not limitation, it may be desirable for a valve of an engine cylinder to be opened during particular times during engine operation, and closed during other times. By way of example and not limitation, it can be common practice to reference valve timing relative to one or more other indices of engine operation, such as a position or periodic phase of cylinder motion, crankshaft rotation, and / or camshaft rotation. By way of example and not limitation, valve opening may be referenced in terms of an extent of valve lift, such as a height or displacement of valve opening relative to a seated closed position of a valve. By way of example and not limitation, valve lift may be referenced against a suitable periodic phase to convey detailed information about valve timing and / or operation. In particular embodiments, a valve lift profile may comprise time-varying information about valve operation. By way of example and not limitation, a valve lift profile may comprise an extent and / or a sequence of valve lifts and / or valve opening displacements over time, for e.g., associated with one or more portions of an engine cycle. In particular embodiments, a rocker arm assembly receiving motion from a cam may correspond to the rocker arm assembly receiving one or more portions of a valve lift profile associated with the cam.

[0038] In particular embodiments, a valvetrain may comprise valve timing devices and / or systems configured to impart and / or modify valve timing. By way of example and not limitation, valve timing systems may comprise mechanical means, such as one or more camshafts configured to rotate based on engine operation, such as indexed to periodic cylinder motion. By way of example and not limitation, a camshaft may comprise one or more cams configured to provide a geometric representation of a desired extent of valve lift for opening one or more valves of interest based on rotation of a corresponding camshaft. By way of example and not limitation, a cam may include one or more lobes rising above a minimum characteristic dimension, e.g., a base circle, to encode a physical manifestation of a desired time-varying evolution of valve lift displacements comprising a valve lift profile, which may be transferred to a suitable interfacing component via rotation of the cam. In particular embodiments, devices and systems for imparting and / or modifying valve timing may not be cam-based in one or more respects. In particular embodiments, valves may be directly or indirectly operated using actuators with or without employing cams. By way of example and not limitation, hydraulic, electromagnetic, and / or pneumatic actuators may be configured to directly or indirectly operate one or more valves.

[0039] In particular embodiments, a rocker arm assembly of a valvetrain may be configured to receive, transmit, modify, and / or selectively transfer one or more valve lift profiles.

[0040] In particular embodiments, receiving of a valve lift profile by a rocker arm assembly may comprise transfer of a force or motion from a suitable mechanism such as described above, for e.g., a cam, or an electromagnetic actuator. By way of example and not limitation, a received motion associated with receiving a valve lift profile may comprise displacements, translational motion, and / or rotational motion. By way of example and not limitation, receiving of a valve lift profile may comprise receiving no force or motion for some or all portions of an engine cycle, for e.g., due to partial or total loss of contact of a roller with a cam, and / or due to a mode change by design.

[0041] In particular embodiments, a rocker arm assembly may be configured to directly or indirectly receive one or more valve lift profiles. By way of example and not limitation, a rocker arm assembly may be configured to directly receive a valve lift profile from a cam via a suitable mechanism, e.g., based on a time-varying or permanent rotational engagement with a roller mechanism. By way of example and not limitation, a rocker arm assembly may be configured to indirectly receive a valve lift profile from a cam via a suitable mechanism, e.g., a pushrod mechanism. In particular embodiments, a force or motion transfer path between a cam and a rocker arm assembly associated with receiving a valve lift profile may additionally or alternatively comprise one or more intermediate components, e.g., a lash adjustment mechanism.

[0042] In particular embodiments, transmitting of a valve lift profile by a rocker arm assembly may comprise conversion of a force or motion associated with a received valve lift profile to a corresponding force or motion applied at a valve-interfacing portion of the rocker arm assembly. By way of example and not limitation, a rocker arm assembly configured to receive motion corresponding to a valve lift profile received from a cam via a roller mechanism may rotate about a rocker shaft and via such rotation, may transmit the received valve lift profile as a corresponding motion applied by an extended structure at a valve end as a valve lift to one or more valves.

[0043] As will be further described herein, in particular embodiments, a rocker arm assembly may modify and / or selectively transfer a valve lift profile. By way of example and not limitation, a rocker arm assembly may be configured to selectively absorb or transmit some or all parts of a received valve lift profile. By way of example and not limitation, a rocker arm assembly may be configured to selectively combine more than one received valve lift profile.

[0044] In particular embodiments, this disclosure describes features, devices, systems, and / or methods that can allow establishing and / or maintaining improved switching performance and latch lash in valvetrains with switchable rocker arms. In particular embodiments, strategies, systems, and / or methods described herein can provide for less stringent tolerance requirements, improved ease of assembly, reduced cost, and / or improved lash and latching performance over the operational life of the valvetrain components and systems. In particular embodiments, benefits described herein may be realized by processing or co-processing portions of the assembly, such as processing to create interfaces associated with a latching system and a stop mechanism while the rocker arm is fixtured in an assembled configuration. By way of example and not limitation, a latch bore (or latch pin bore) of a latch mechanism may be created in a combined process along with creating a stop bore of a stop mechanism, for e.g., by machining, drilling, reaming or another suitable process, while movable parts of a rocker arm assembled are constrained in an assembled configuration for processing, e.g., by a fixture. In particular embodiments, systems and methods disclosed herein may comprise processing latch bores and / or lash stop interfaces while a plurality of sides of the rocker arms assembly are constrained in their assembled position, for e.g., by fixturing. In particular embodiments, a plurality of latch bores or bore sections, such as across or through a set of rocker arm portions, may be processed to the same diameter. In particular embodiments, one or more portions of a latch bore may be provided with an insert, which can eliminate the need and costs of precision grinding for lash setting.

[0045] In particular embodiments, latch lash may be established with precise, expensive finishing operations, e.g., grinding. In particular embodiments, measurement of latch pins may require sorting into categories, wherein sorted pins may then be matched up with rocker arms according to specific subassembly lash measurements. As will be further described herein, in particular embodiments, relative position(s) of critical features of rocker arm assemblies may be precisely manufactured, processed, assembled, and / or maintained during operation without requiring time consuming and / or expensive operations, such as grinding. By way of example and not limitation, processing or co-processing latch bores and / or stop bores and / or stop surfaces in an assembled configuration of the rocker arm assembly may enable such benefits. By way of example and not limitation, such methods, devices and / or system may allow for reduced lash variation, for e.g., without sizing and / or sorting latch pins according to tolerance bands.

[0046] In particular embodiments, methods, devices, and / or systems such as described in this disclosure may eliminate the need for a bushing in particular pivot structures, such as rocker shaft bores. By way of example and not limitation, with nitride layer on pivot bores, there may be no functional need for a bushing, which may be intended to hold a plurality of rocker arm bodies in place before assembly on a rocker shaft. In particular embodiments, a bushing may require tight tolerances, e.g., diametral tolerances, and / or machining of oil channels, which can increase processing cost and / or time. In particular embodiments described herein, devices associated with stop assemblies and / or latch assemblies, such as stop pins and latch pins, may be employed to hold the assembly prior to engine install, with minimal lash.

[0047] Separately or additionally, by way of example and not limitation, some alternative methods or stop features of holding rocker arm bodies and / or components in position against particular components, e.g., a biasing spring of a lost motion assembly, may cause a nominal torque to act perpendicular to the rocker shaft axis on portions of the rocker arm assembly. Accordingly, precise, time-consuming and / or costly machining of rocker arm assembly features may need to be performed with respect to these and other critical features. In particular embodiments, complex geometry may be required to be included in rocker arm assemblies to overcome the abovementioned challenges, which can require further costly machining operations.

[0048] Separately or additionally, some alternative stop features are not suitable for preventing over-extension of one or more portions of a rocker arm assembly beyond intended design limits, such as due to the action of a lost motion spring. By way of example and not limitation, over-extension may allow an engine valve bridge to be displaced in the event of a critical shift. In particular embodiments, as will be further described herein, particular features of a stop assembly, e.g., stop pin interfacing with a stop bore, and / or provisioning a stop pin clearance feature, may be employed to prevent over-extension and / or other unintended deviation of rocker arm assembly operation from intended design limits, as will be further described herein.

[0049] In particular embodiments, a valvetrain system comprising a rocker arm assembly may enable such functions and benefits as those described herein. While this disclosure may describe particular kinds of valvetrain architectures and / or switchable rocker arm designs to provide a better understanding, it will be appreciated that this disclosure contemplates any suitable valvetrain architecture and / or switchable rocker arm design for performing such functions and / or obtaining such benefits. By way of example and not limitation, systems and methods described herein may be adapted to any suitable valvetrain architecture, such as Types I through V, and any such variations are fully contemplated herein in any suitable combination.

[0050] Systems and methods described herein may be adapted to many kinds of switching mechanisms and / or actuation methods for implementing switchable rocker arm systems and / or switchable lost motion mechanisms. In particular embodiments, hydraulically driven actuation systems described herein by way of non-limiting example may be complemented or replaced by electrically or electromagnetically driven actuation systems, such as using solenoids. In particular embodiments, valve lift profiles may be directly transferred to a rocker arm assembly from a cam, such as via a roller mechanism. In particular embodiments, valve lift profiles may be indirectly transferred to a rocker arm assembly, such as via a pushrod mechanism, and / or via a hydraulic lash adjuster or other mechanism.

[0051] By way of example and not limitation, collapsible and / or extendable systems, capsule based systems, and / or other lost motion mechanisms with or without springs may employed in particular embodiments. By way of example and not limitation, latch mechanisms comprising one or more pins may be employed. In particular embodiments, one or more pins of the latch mechanism employed herein may be respectively biased along one or more directions.

[0052] By way of example and not limitation, systems and methods described herein may be adapted to multiple applications, including different applications than suggested or described herein, that may be provided or enabled by switchable valvetrains, e.g., variable valve timing applications, cylinder deactivation applications, and / or engine braking applications, and such variations are fully contemplated herein in any suitable combination. While particular examples are included for providing the features, functions, and / or supporting the applications disclosed herein, it will be appreciated that any other suitable methods, systems, applications, and combinations thereof are fully contemplated in this disclosure.

[0053] With reference to the figures, FIG. 1 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments. FIG. 2 illustrates a schematic sectioned top view of a rocker arm assembly, according to particular embodiments. FIG. 3 illustrates a schematic partially exploded perspective view of a rocker arm assembly, according to particular embodiments.

[0054] In particular embodiments, a rocker arm assembly 110 may be configured to rotate about a rocker shaft passing through a rocker shaft bore 120. In particular embodiments, rocker arm assembly 110 may comprise a first body 130 and a second body 140 operatively coupled to first body 130.

[0055] In particular embodiments, rocker arm assembly 110 may comprise a valve portion 132 configured to operatively engage with one or more valves. By way of example and not limitation, first body 130 may comprise one or more valve portions, such as valve portion 132 depicted in the figures herein to provide an understanding. In particular embodiments, second body 140 may separately or additionally comprise one or more valve portions, such as valve portion 132, and such embodiments are fully contemplated herein. In particular embodiments, a valve portion 132 of rocker arm assembly 110 may comprise one or more extended structures, such as to respectively engage one or more valves. By way of example and not limitation, an extended structure of a valve portion 132 of rocker arm assembly 110 may comprise a suitable interfacing structure for directly or indirectly engaging a valve, such as via E-foot 135. In particular embodiments, one or more portions of a valve portion 132 may be configured to engage a plurality of valves, such as via a valve bridge. In particular embodiments, a valve portion 132 of rocker arm assembly 110 may comprise one or more switchable assemblies, such as a collapsible and / or extendable capsule assembly.

[0056] In particular embodiments, rocker arm assembly 110 may comprise a cam portion 142 configured to receive one or more valve lift profiles, such as directly or indirectly from one or more cams. By way of example and not limitation, second body 140 may comprise one or more cam portions, such as cam portion 142, depicted in the figures herein to provide an understanding. In particular embodiments, first body 130 may separately or additionally comprise one or more cam portions, such as cam portion 142, and such embodiments are fully contemplated herein. In particular embodiments, cam portion 142 may comprise a roller mechanism, such as roller 150, which may be configured to be directly engageable with a cam.

[0057] In particular embodiments, first body 130 and second body 140 may be symmetrically arranged in a geometric and / or load path and force transfer context. In particular embodiments, first body 130 and second body 140 may be asymmetrically arranged in a geometric and / or force transfer context. In particular embodiments, such as described herein, first body 130 and second body 140 may be arranged such that one body is an inner member, and the other body forms an outer member enclosing and supporting the inner member. In particular embodiments, a portion of one of the first body 130 or second body 140 of rocker arm assembly 110 may be axially enclosed and / or supported by a forked portion of the other of first body 130 or second body 140 rocker arm assembly 110. By way of example and not limitation, such as depicted in at least FIG. 3, first body 130 may comprise a first outer portion 160 and a second outer portion 170 enclosing both sides of an inner portion 180 of second body 140. By way of example and not limitation, suitable arrangements and configurations such as disclosed herein can permit one of the bodies, such as second body 140, to be axially supported from both ends to reduce side-to-side force asymmetries, twist, wobble, and / or latching inconsistencies. Separately or additionally, suitable arrangements and configurations such as disclosed herein may reduce or improve control of operational wear or uneven wear over time. In particular embodiments, such suitable arrangements and configurations can also reduce the overall material and cross-section needed to sustain operational loads, leading to less costly and / or lighter parts. In particular embodiments, first body 130 and second body 140 may be arranged in a side-by-side configuration, such as depicted in FIGS. 7-9 by way of example and not limitation. By way of example and not limitation, suitable arrangements and configurations such as disclosed herein can permit compact and / or light rocker arm assembly 110 capable of meeting challenging packaging constraints and / or weight requirements.

[0058] In particular embodiments, rocker arm assembly 110 may comprise one or more switchable mechanisms. In particular embodiments, one or more switchable mechanisms of rocker arm assembly 110 may be employed to selectively transmit, modify, and / or absorb one or more portions of one or more valve lift profiles received by rocker arm assembly 110. By way of example and not limitation, rocker arm assembly 110 may comprise a latch assembly, such as latch assembly 400. In particular embodiments, latch assembly 400 may comprise a latch bore 410. In particular embodiments, latch bore 410 may comprise a plurality of bore portions disposed across multiple portions of rocker arm assembly 110. In particular embodiments, latch bore 410 may be at least partially disposed in a roller of cam portion 142, such as roller 150.

[0059] In particular embodiments, first body 130 and second body 140 may be configured to be rotatable about one or more of rocker shaft bore 120 and / or latch bore 410. In particular embodiments, such as depicted in FIGS. 7-9 by way of example and not limitation, first body 130 and second body 140 may be additionally or alternatively configured to be rotatable about a pivot axle, such as pivot axle 145.

[0060] In particular embodiments, latch assembly 400 may be operable in one or more states, such as a first latch state and a second latch state. In particular embodiments, in the first latch state, latch assembly 400 may be configured to operatively couple first body 130 and second body 140, for e.g., to prevent relative motion between first body 130 and second body 140. By way of example and not limitation, in the first latch state of latch assembly 400, first body 130 and second body 140 may be coupled to rotate and / or otherwise move as an integral unit, such as corresponding to an overall motion of rocker arm assembly 110 during operation through an engine cycle. In particular embodiments, in the second latch state, latch assembly 400 may be configured to permit relative motion between first body 130 and second body 140, for e.g., to permit one of first body 130 and second body 140 to receive and / or sustain a force or motion without transmitting said force or motion to the other of first body 130 and second body 140.

[0061] By way of example and not limitation, second body 140 when configured with a cam portion 142 may be configured to receive a valve lift profile. In particular embodiments, corresponding to a first latch state of latch assembly 400, second body 140 may be coupled to first body 130 to transmit the received valve lift to first body 130. In particular embodiments, corresponding to a second latch state of latch assembly 400, second body 140 may be decoupled from first body 130 to prevent some or all of the valve lift from transmitting to first body 130.

[0062] In particular embodiments, latch bore 410 may be configured to pass through at least a portion of each of first body 130 and second body 140. By way of example and not limitation, such as depicted in FIG. 8, latch bore 410 may pass through a full cross-sectional thickness of one body and a portion of the cross-sectional thickness of the other body. In particular embodiments, such as depicted in FIGS. 2 and 6 by way of example and not limitation, latch bore 410 may pass through an entire cross-sectional thickness of both the first body 130 and second body 140.

[0063] In particular embodiments, corresponding to particular configurations of rocker arm assembly 110, latch bore 410 may be configured to be disposed in at least a portion of each of the aligning portions, such as each of the outer portions and the inner portions, of first body 130 and second body 140. By way of example and not limitation, such as further depicted in FIGS. 2 and 6, latch bore 410 may be configured to be disposed in at least a portion of each of first outer portion 160, second outer portion 170, and inner portion 180. In particular embodiments, latch bore 410 may be configured to pass through a respective cross-sectional thickness of each of first outer portion 160, second outer portion 170, and inner portion 180.

[0064] In particular embodiments, latch assembly 400 may comprise one or more pins and / or pistons. In particular embodiments, one or more latch pins of latch assembly 400 may be configured to be latchable or unlatchable, such as to selectively transmit a drive valve lift profile received from a cam portion of rocker arm assembly 110, such as cam portion 142. In particular embodiments, as will be further described herein, one or more such pins and / or pistons of latch assembly 400 may be disposed in latch bore 410, such as slidably disposed to be selectively movable within latch bore 410, and such that latch assembly 400 may be operated to switchable couple or decouple first body 130 and second body 140. In particular embodiments, to enable selective latching by latch assembly 400, one or more latch pins may be configured to selectively slide into, protrude into, and / or out of a portion of latch bore 410. In particular embodiments, one or more axial ends of latch bore 410 may comprise a biasing mechanism, such as biasing member 450. By way of example and not limitation, a biasing mechanism may comprise one or more springs. In particular embodiments, a biasing mechanism may separately or additionally comprise one or more optional force transfer and / or support members, such as support end 460 and / or support end 465, by way of non-limiting example.

[0065] In particular embodiments, latch assembly 400 may be hydraulically actuated, such as based on receiving a selectively pressurized hydraulic fluid. Separately or additionally, in particular embodiments, latch assembly 400 may be electrically or electromagnetically actuated, such as by a solenoid.

[0066] In particular embodiments, switchable latch assembly 400 may be actuated from one side of one or more slidable members (e.g., latch pins), or from a plurality of sides. In particular embodiments, actuation may be based on differential action based on relative forces applied from a plurality of sides. By way of example and not limitation, FIG. 3 illustrates a piston 440 that is axially movable downward (in the frame of reference of the figure) when actuated or energized, and / or that is axially restored to the upward when de-actuated or de-energized, for e.g., based on a restoring force applied by biasing member 450. In particular embodiments, piston 440 may be selectively movable or translatable based on selectively pressurizing a chamber, such as based on hydraulic fluid being fed through hydraulic bore 470. In particular embodiments, such as illustrated in FIG. 2, hydraulic bore 470 may be fluidly connected to a controllable pressurized hydraulic fluid source. By way of example and not limitation, a solenoid-based oil control valve (OCV) may be used to selectively pressurize a hydraulic line to latch assembly 400, such as via rocker shaft bore 120 via hydraulic bore 470.

[0067] In particular embodiments, a plurality of actuation means may be provided, for e.g., to provide multiple and / or differential methods of actuating one or more movable elements of latch assembly 400. By way of example and not limitation, FIG. 8 depicts a movable latch pin 430, which may be selectively actuated based on controlling a hydraulic fluid pressure provided via a hydraulic bore 470. Additionally or alternatively, one or more other members, such as depicted by piston 440 in FIG. 8 by way of non-limiting example, may be movable and / or otherwise controllable, individually or in combination. By way of example and not limitation, movable piston 440 in FIG. 8 may be selectively actuated based on controlling a hydraulic fluid pressure fed via a second hydraulic bore 475.

[0068] In particular embodiments, latch assembly 400 may comprise configurations of movable latching members, such as comprising one or more of each of latch pins and / or pistons. By way of example and not limitation, a latch pin may be configured in particular embodiments to movably block or allow relative motion between components, such as by interference. In particular embodiments, a piston may be configured to receive and / or transmit one or more forces to other components of latch assembly 400, such as an actuating force and / or a restoring or biasing force.

[0069] FIG. 4 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments, with an inset depicting particular details of an exemplary stop mechanism. FIG. 5A illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments, with an inset depicting particular details of an exemplary stop mechanism. FIG. 5B illustrates a schematic side view of a rocker arm assembly, according to particular embodiments.

[0070] As will be further described herein, in particular embodiments, latch assembly 400 may comprise one or more stop mechanisms, such as stop mechanism 300. In particular embodiments, stop mechanism 300 may comprise a stop bore 320. In particular embodiments, stop mechanism 300 may comprise a member, such as an extended member formed as a stop pin 330. In particular embodiments, stop pin 330 may be disposed in stop bore 320.

[0071] In particular embodiments, such as depicted in the inset of FIG. 5A, stop bore 320 may comprise a conforming portion 322. By way of example and not limitation, conforming portion 322 may be configured to include one or more characteristic dimensions of stop pin 330, such as a basis in a radius of curvature of stop pin 330. In particular embodiments, a curvature of conforming portion 322 may be configured to receive stop pin 330. In particular embodiments, conforming portion 322 may have a radius of curvature based on, and / or equal to, a radius of curvature of stop bore 320. In particular embodiments, conforming portion 322 may be configured in the form of a scallop. In particular embodiments, conforming portion 322 may permit a stop feature or stop surface for stop pin 330 within stop bore 320. In particular embodiments, conforming portion 322 may allow a greater surface area for interfacing with stop bore 320, with reduced risk of indentations, accelerated, and / or uneven wear. Accordingly, in particular limitation, conforming portion 322 may improve the operational stability and long-term alignment and latch lash control of rocker arm assembly 110. By way of example and not limitation, a scalloped stop surface of conforming portion 322 as a part of stop bore 320 may be configured to mark and / or hold a normal operational position of rocker arm assembly 110 against stop pin 330.

[0072] It will be appreciated that while features of stop mechanism 300 and / or stop pin 330 may be illustrated or discussed in detail with respect to particular embodiments disclosed herein, this disclosure contemplates incorporation of one or more features of stop mechanism 300 and / or stop pin stop pin 330 in any suitable combination or embodiment.

[0073] By way of example and not limitation, FIG. 2 depicts a latch assembly 400 comprising three movable latching members, i.e., latch pin 430, piston 440, and piston 445. In particular embodiments, piston 440 may be configured to act to displace latch pin 430, such as based on receiving an actuating force due a selectively pressurized fluid chamber fed by hydraulic bore 470. In particular embodiments, piston 445 may be configured to act to displace latch pin 430, such as based on providing a restoring or biasing force due to biasing member 450. In particular embodiments, an actuating force due to piston 440 when acted upon by a pressurized fluid may be configured to exceed an effective restoring or biasing force acting on latch pin 430 due to biasing member 450. Accordingly, in particular embodiments, latch assembly 400 may be configured to selectively move latch pin 430 so that the axial ends or limits of latch pin 430 may be aligned in a non-interfering configuration, thereby acting to decouple and allow relative motion between first body 130 and second body 140.

[0074] FIG. 6 illustrates a schematic sectioned top view of a rocker arm assembly, according to particular embodiments.

[0075] By way of example and not limitation, FIG. 6 depicts a latch assembly 400 comprising four movable latching members, i.e., latch pin 430, latch pin 435, piston 440, and piston 445. In particular embodiments, piston 440 and piston 445 may be configured to act to displace latch pin 430 and latch pin 435, respectively, such as based on the pistons receiving an outward directed actuating force by a selectively pressurized fluid chamber fed by hydraulic bore 470. In particular embodiments, piston 440 and piston 445 may be respectively receive a restoring or biasing force due to biasing member 450 and / or biasing member 455, such as via latch pin 430 and latch pin 435, respectively. In particular embodiments, an actuating force due to piston 440 and piston 445 when acted upon by a pressurized fluid may be configured to exceed an effective restoring or biasing force due to biasing member 450 and / or biasing member 455. Accordingly, in particular embodiments, latch assembly 400 may be configured to selectively move latch pin 430 and / or biasing member 455 so that the axial ends or limits of latch pin 430 and / or latch pin 435 may be separately or concurrently aligned in a non-interfering configuration, thereby acting to decouple and allow relative motion between first body 130 and second body 140. In particular embodiments, one or more end supports, such as C-clips or washers, may be provided to support a biasing member or other components of latch assembly 400. By way of example and not limitation, FIG. 6 depicts end support 480 and end support 485 to enclose, support, and / or constrain biasing member 450 and biasing member 455, respectively, of latch assembly 400.

[0076] FIG. 7 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments. FIG. 8 illustrates a schematic sectioned bottom view of a rocker arm assembly, according to particular embodiments. FIG. 9 illustrates a schematic partially exploded perspective view of a rocker arm assembly, according to particular embodiments.

[0077] By way of example and not limitation, FIG. 8 depicts a latch assembly 400 comprising two movable latching members, i.e., latch pin 430 and piston 440.

[0078] In particular embodiments, latch assembly 400 as contemplated herein may separately or additionally comprise other kinds of mechanisms, and / or other components than latching pins and / or piston. By way of example and not limitation, extendable and / or collapsible capsule system.

[0079] It will be appreciated that while particular aspects of structure, configuration, operation, and actuation are described herein with reference to specific embodiments of latch assembly 400 to provide a better understanding, this disclosure contemplates any suitable structure, configuration, operation, and / or actuation or suitable combination thereof for latch assembly 400, and in any combination with other structures or features as described herein.

[0080] In particular embodiments, one or more movable latching members, e.g., piston 440 of FIG. 2, may be configured to be switchably actuated or energized, such as via hydraulic pressure and / or action due to a solenoid. In particular embodiments, one or more movable latching members, e.g., piston 445 of FIG. 2, may be configured to provide a biasing force and / or a restoring force. In particular embodiments, one or more movable members of latch assembly 400 may be configured to receive an actuation force from one direction, or one or more of them may be configured to receive actuation force(s) from multiple directions. In particular embodiments, one or more movable members of latch assembly 400 may be configured to receive a restoring and / or biasing force from one direction, or one or more of the movable members may be configured to receive restoring and / or biasing force(s) from multiple directions. In particular embodiments, a plurality of movable members may be configured to move along a same direction when actuation is enabled, and / or when actuation is disabled, wherein the direction for actuation enabled relative to the direction for actuation disabled can be identical or different. In particular embodiments, a plurality of movable members may be configured to move along different directions when actuation is enabled, and / or when actuation is disabled.

[0081] In particular embodiments, rocker arm assembly 110 may comprise a lost motion assembly, such as lost motion assembly 200. In particular embodiments, lost motion assembly 200 may comprise one or more systems configured for absorbing displacement and / or motion. By way of example and not limitation, lost motion assembly 200 may comprise a lost motion spring 210 capable of absorbing a valve lift received from cam portion 142, such as by compressing based on receiving force, displacement, and / or energy associated with a valve lift from a cam. In particular embodiments, lost motion spring 210 may be supported by an optional lost motion support member 220.

[0082] In particular embodiments, lost motion assembly 200 may be secured to and / or supported by one or more connection assemblies connected to portions of rocker arm assembly 110. In particular embodiments, a first connection 230 may operably couple lost motion assembly 200 to a suitable portion of rocker arm assembly 110, such as to first body 130 as a non-limiting example. In particular embodiments, a second connection 240 may operably couple lost motion assembly 200 to another suitable portion of rocker arm assembly 110, such as second body 140 by way of non-limiting example. In particular embodiments, first connection 230 and / or second connection 240 may comprise one or more pivotable couplings to pivotably couple structures, such as described and / or illustrated herein. In particular embodiments, first connection 230 and / or second connection 240 may comprise one or more slots, anchors, or other suitable means for coupling lost motion assembly 200 with one or more remaining portions of rocker arm assembly 110. By way of example and not limitation, a corresponding support slot 235 and / or support slot 245 such as depicted in at least FIGS. 1 and 9 may be employed to couple, connect, and / or support lost motion assembly 200.

[0083] As discussed, while particular features of specific latch mechanisms and / or specific lost motion mechanisms (e.g., latch assembly 400 and lost motion assembly 200, respectively) are described and / or illustrated herein to provide a better understanding, it will be appreciated that other suitable forms and features of mechanisms are fully contemplated in this disclosure. By way of example and not limitation, a switchable assembly to selectively enable or disable operation of lost motion assembly 200 may be disposed in and / or otherwise combined with lost motion assembly 200 in particular embodiments.

[0084] As previously discussed, in particular embodiments, latch assembly 400 latch may comprise one or more stop mechanisms, such as stop mechanism 300. In particular embodiments, such as depicted in FIG. 4 by way of example and not limitation, stop mechanism 300 may comprise one or more extended stop features, such as stop notch 310, configured to constrain a range of potential motion of latch assembly 400, such as a potential relative motion between first body 130 and second body 140. By way of example and not limitation, such an extended stop feature, e.g., stop notch 310, may be configured to engage with a suitable interfering feature, such as stop cutout 315.

[0085] In particular embodiments, such as depicted in at least FIGS. 1, 5A-5B, and 7 by way of example and not limitation, stop mechanism 300 may comprise a stop bore 320 and / or an extended member such as stop pin 330. In particular embodiments, a stop bore 320 of stop mechanism 300 may be configured to pass through at least a portion of each of first body 130 and second body 140.

[0086] In particular embodiments, stop mechanism 300 may be configured to operatively constrain a range of relative motion between first body 130 and second body 140. In particular embodiments, stop pin 330 may be operatively secured to first body 130 or second body 140, for e.g., to constrain motion of stop pin 330 along particular directions such as radially. In particular embodiments, one or more portions of stop bore 320 in the other of first body 130 and second body 140 may be suitably sized to permit stop pin 330, and a portion of rocker arm assembly 110 operatively secured thereto, to traverse within a permissible range of relative motion of first body 130 and second body 140 while constraining or otherwise preventing relative motion thereof beyond permissible ranges, e.g., over-extension. By way of example and not limitation, such as illustrated in at least FIGS. 2 and 3, stop pin 330 may be operatively secured to a portion of second body 140, e.g., inner portion 180, or another suitable portion. Accordingly, in particular embodiments following such a non-limiting example, stop bore 320 may be formed or otherwise configured in one or more portions of the other body, such as first body 130, to permit stop pin 330 operatively secured to second body 140 to move within stop bore 320 to enable a permissible range of relative motion of first body 130 and second body 140 while constraining or otherwise preventing relative motion thereof beyond permissible ranges. In particular embodiments, other benefits of alignment, manufacturing ease and cost, and / or consistent force and torque loading benefits, among others, may be realized.

[0087] In particular embodiments, such as depicted in FIG. 5A by way of example and not limitation, stop bore 320 of stop mechanism 300 may comprise one or more additional features, such as clearance cut 325. In particular embodiments, one or more such additional features, e.g., clearance cut 325, may be provided in one or more portions of whichever of first body 130 or second body 140 is not coupled to stop pin 330. By way of example and not limitation, FIG. 5A depicts clearance cut 325 provided in one or more portions of first body 130, but not in second body 140, wherein stop pin 330 is operatively secured to first body 130. In particular embodiments, a clearance cut such as clearance cut 325 may be machined into one or more portions of first body 130 or second body 140 wherein stop pin 330 is not secured or otherwise operatively constrained. By way of example and not limitation, clearance cut 325 may be machined into both sides of outer arms of first body 130 or second body 140, e.g., first outer portion 160 and / or second outer portion 170, while preserving the critical stop surface from the original hole of stop bore 320. In particular embodiments, clearance cut 325 may have a relatively loose tolerance on one side, but an opposing side of clearance cut 325 may be designed and processed to prevent an over-travel and / or over-extension of one or more portions of rocker arm assembly 110. In particular embodiments, clearance cut 325 may be configured to operatively constrain a relative motion between first body 130 and 140, for e.g., as stop pin 330 may otherwise traverse to contact a portion of an arm of first body 130 or second body 140 (whichever does not have stop pin 330 secured to it), such as if a biasing member of lost motion assembly 200, e.g., lost motion spring 210, is forced to compress more than intended by design. By way of example and not limitation, in particular embodiments corresponding to undesirable operational scenarios, a rocker arm assembly 110 may go into a critical shift, wherein latch pins may shift during valve lift, and / or may lead to unintentional decoupling of first body 130 and second body 140.

[0088] In particular embodiments, clearance cut 325 may be provided based on enlarging a portion of stop bore 320 in first body 130 or second body 140, for e.g., corresponding to whichever of first body 130 or second body 140 does not have stop pin 330 secured to it. In particular embodiments, one or more edges of clearance cut 325 may exceed a normal range of travel associated with operation of rocker arm assembly 110. By way of example and not limitation, one or more edges of clearance cut 325 may define one or more limits of over-travel or over-extension associated with operation of rocker arm assembly 110, such as by operatively constraining a range of motion of first body 130 and second body 140 during operation of rocker arm assembly 110.

[0089] In particular embodiments, a processing of clearance cut 325, e.g., by machining, may be optionally delayed, for e.g., as a separate step after other parts of stop bore 320 have been processed together for maintaining alignment. In particular embodiments, an extent of clearance cut 325 may exceed a normal operational travel of rocker arm assembly 110, such as that associated with a range of motion of lost motion assembly 200. By way of example and not limitation, one or more limits of a greater travel extent of clearance cut 325 than ordinary operational travel may be configured to prevent over-travel and / or over-extension of rocker arm assembly 110.

[0090] By way of example and not limitation, a range of relative motion between first body 130 and second body 140 such as described above may be associated in particular embodiments with a decoupled state of latch assembly 400 permitting such relative motion between first body 130 and second body 140. By way of example and not limitation, as discussed previously, such a decoupled state may be associated with a second latch state of latch assembly 400.

[0091] In particular embodiments, one or more features such as stop bore 320 may be provided, such as by machining or other processing, in at least a portion of each of first body 130 and second body 140 when rocker arm assembly 110 is constrained in an assembled configuration or state. By way of example and not limitation, first body 130 and second body 140 may be held fixtured on rocker shaft bore 120 and / or other indexing features of rocker arm assembly 110, such as one or more of bearing axle bore(s), valve side bore(s) or feature(s), hydraulic lash bore(s), and / or lash screw bore(s). By way of example and not limitation, a single bore may be reamed through both first body 130 and second body 140 for indexing and locating components of latch assembly 400, while first body 130 and second body 140 of rocker arm assembly 110 are held fixtured in the assembled position. By way of example and not limitation, such a method may permit precise location of the relative position of latch pin 430 in both first body 130 and second body 140 in a rapid, precise, and inexpensive way.

[0092] By way of example and not limitation, it may be important for reliable, consistent and / or efficient operation of rocker arm assembly 110 to provide and maintain suitable operational clearances related to movable members of latch assembly 400, such as latch pin clearance 432 for latch pin 430. By way of example and not limitation, a stop mechanism operatively misaligned with latch assembly 400, for e.g. such that suitable clearances are not properly provided or maintained, may cause unreliable operation or premature failure, such as due to contact and / or other interference during operation, and / or due to excessive latching force requirements based on movable member friction with a corresponding bore. Accordingly, particular embodiments require the use of expensive and / or time-consuming operations, e.g., by grinding, to create and precisely refine relative tolerances between various subassemblies of rocker arm assembly 110, for example, latch bore 410 of latch assembly 400 and stop bore 320 of stop mechanism 300.

[0093] In contrast, in particular embodiments contemplated and described herein, a plurality of alignment-sensitive features of rocker arm assembly 110 may be simultaneously or sequentially processed during a single manufacturing or assembly operation, such as wherein first body 130 and second body 140 may be constrained, such as by a fixture. By way of example and not limitation, latch bore 410 of latch assembly 400 and stop bore 320 of stop mechanism 300 may be simultaneously or sequentially processed, e.g., by drilling, reaming, and / or other suitable operation, while first body 130 and second body 140 may be constrained, such as by a fixture assembly.

[0094] By way of example and not limitation, such a method may eliminate the need for expensive and / or time-consuming processing, e.g., comprising grinding, of latch bores, such as to fix deviations of bore size and / or position, which may separately or additionally be exacerbated after heat treatment of rocker arm assembly 110. In particular embodiments, one or pins, such as one or more of stop pins, latch pins, and / or pistons, may be made to one category with a one-size-fits-all strategy. In particular embodiments, lash variation may be accounted for primarily in the controlling a tolerance of a recess on the pins.

[0095] In particular embodiments, one or more sections of latch bore 410 may be respectively created in at least a portion of each of first body 130 and second body 140 by processing, e.g., by reaming, to the same diameter for simple processing. In particular embodiments, one or more movable components of latch assembly 400, e.g., actuation pistons such as piston 440 and / or piston 445, may utilize a smaller bore than latch bore 410. By way of example and not limitation, to install such smaller-than-bore elements such as a piston, a sleeve or insert, e.g., insert 420, may be inserted within latch bore 410. In particular embodiments, insert 420 may be secured within latch bore 410 via a simple, robust mechanism, such as ball 428 depicted in FIG. 6 by way of example and not limitation.

[0096] In particular embodiments, insert 420 may be either secured with a light press fit. In particular embodiments, depicted in FIG. 6 by way of example and not limitation, a suitable member, such as ball 428, may be pressed to plug particular portions of hydraulic bore 470, such as the supply hole interfaces with an external chamfer centered on a sleeve or insert 420. In particular embodiments, if secured with ball 428, a diametral size of insert 420 may be configured to provide a slip fit while limiting hydraulic fluid flow through the clearance. In particular embodiments, such a clearance may also function as an aide to purge oil behind the pistons during the transition to a deenergized or actuator-off state of latch assembly 400.

[0097] In particular embodiments, stop bore 320 of stop mechanism 300 may be separately or additionally processed to be disposed through at least a portion of each of first body 130 and second body 140 when the bodies are constrained in an assembled configuration of rocker arm assembly 110. In particular embodiments, stop bore 320 and latch bore 410 may be co-processed, e.g., processed sequentially or simultaneously during a common operation while first body 130 and second body 140 are constrained in an assembled configuration of rocker arm assembly 110. In particular embodiments, a stop feature, e.g., stop pin 330, may be secured into at least a portion of one or the other of first body 130 or second body 140. By way of example and not limitation, stop pin 330 may be secured to an inner portion, such as inner portion 180. By way of example and not limitation, stop pin 330 may be secured as disclosed using a press fit, and / or other interference fit. By way of example and not limitation, such a secured stop feature, e.g., stop pin 330, may be accordingly configured to engage with the other of first body 130 or second body 140 wherein stop pin 330 is not secured. By way of example and not limitation, stop pin 330 may be configured to engage at one end of stop pin 330 with the other body.

[0098] In particular embodiments, stop pin 330 may be configured to engage with a plurality of arm portions, e.g., two outer portions such as first outer portion 160 and second outer portion 170, at both ends of the pin. Accordingly, in particular embodiments, such a configuration can prevent a torque from acting that may be otherwise imparted by a stop feature that is offset from a corresponding line or plane of action of a force and / or interference, e.g., a line of action of a biasing force of lost motion spring 210. In particular embodiments, precisely but rapidly creating relatively indexed locations (e.g., engageable stop features of stop mechanism 300 and / or latch bore 410 of latch assembly 400) with reference to first body 130 and second body 140, such as by co-processing means discussed herein, may avoid the need for particular structures, features, and / or processes typically needed, and / or may ensure other critical features are relatively positioned correctly and quickly, thereby saving time, cost, and / or complexity associated with the processing, part(s), and / or system. By way of example and not limitation, a bushing that may be required to be pressed into rocker shaft bores of alternative rocker arm assemblies may be avoided based on systems and methods described herein.ClausesClause 1. A rocker arm assembly comprising: a first body and a second body operatively coupled to the first body, at least one of the first body or the second body configured to be rotatable about a rocker shaft; a latch assembly operable in a first latch state and a second latch state and comprising a latch bore passing through at least a portion of each of the first body and the second body, wherein the latch assembly is configured to: operatively couple the first body and the second body to prevent relative motion therebetween in the first latch state, and permit relative motion between the first body and the second body in the second latch state; and a stop mechanism comprising a stop bore and a stop pin disposed in the stop bore, the stop bore configured to pass through at least a portion of each of the first body and the second body, wherein the stop mechanism is configured to operatively constrain a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0100] Clause 2. The rocker arm assembly of clause 1, wherein the stop bore of the stop mechanism comprises a first portion associated with the second body, wherein a radius of curvature of the first portion is configured based on a radius of curvature of the stop pin.

[0101] Clause 3. The rocker arm assembly as in clauses 1 or 2, wherein the stop bore comprises a second portion associated with the second body, the second portion configured to prevent over-travel of the first body or the second body during operation of the rocker arm assembly.

[0102] Clause 4. The rocker arm assembly of clause 3, wherein the second portion of the stop bore is configured to overlap with at least a portion of the stop bore in the second body.

[0103] Clause 5. The rocker arm assembly as in clauses 3 or 4, wherein one or more edges of the second portion define a limit of allowable travel of the stop pin during operation of the rocker arm assembly.

[0104] Clause 6. The rocker arm assembly as in any of clauses 1 to 5, wherein one of the first body or the second body comprises a comprises a cam portion configured to receive a valve lift profile from a cam, and wherein the other of the first body or the second body comprises a valve portion configured to operatively engage with one or more valves.

[0105] Clause 7. The rocker arm assembly as in any of clauses 1 to 6, wherein the stop pin is operatively secured to the first body.

[0106] Clause 8. The rocker arm assembly as in any of clauses 1 to 7, wherein one of the first body or the second body comprises a forked portion having a first outer portion and a second outer portion configured to axially enclose and support an inner portion of the other of the first body or the second body.

[0107] Clause 9. The rocker arm assembly of clause 8, wherein the latch bore is configured to be disposed in at least a portion of each of the first outer portion, the second outer portion, and the inner portion.

[0108] Clause 10. The rocker arm assembly of clause 9, wherein the latch bore passes through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

[0109] Clause 11. The rocker arm assembly of clause 10, wherein the stop bore passes through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

[0110] Clause 12. The rocker arm assembly of clause 6, further comprising a lost motion assembly operatively coupled to the first body and the second body and configured to selectively absorb at least a portion of the valve lift profile received from the cam.

[0111] Clause 13. The rocker arm assembly of clause 12, wherein the lost motion assembly absorbing the at least a portion of the valve lift profile is associated with operating the latch assembly in the second latch state.

[0112] Clause 14. The rocker arm assembly of clause 12, wherein the lost motion assembly is operable within a range comprising a collapsed position and an extended position.

[0113] Clause 15. The rocker arm assembly of clause 14, wherein the lost motion assembly comprises a lost motion spring, and wherein the lost motion spring is configured to bias the lost motion assembly toward the extended position.

[0114] Clause 16. The rocker arm assembly of clause 12, wherein the stop mechanism comprises a stop surface configured to engage the stop pin to prevent an overextension of the lost motion assembly.

[0115] Clause 17. The rocker arm assembly as in any of clauses 1 to 8, wherein the latch assembly further comprises one or more latch pins, wherein the one or more latch pins are hydraulically or electrically actuated to selectively decouple the first body and the second body.

[0116] Clause 18. A method of making a rocker arm assembly, comprising: constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation; providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly comprises the latch bore; providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly comprises the stop bore and a stop pin; and disposing the stop pin in the stop bore and coupling the stop pin to one of the first body or the second body so that the stop mechanism operatively constrains a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0117] Clause 19. The method of clause 18, wherein the latch bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body.

[0118] Clause 20. The method as in clauses 18 or 19, wherein the stop bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body.

[0119] Clause 21. The method as in any of clauses 18 to 20, further comprising providing a conforming portion associated with the stop bore in the second body such that a radius of curvature of the conforming portion is configured to receive the stop pin, wherein the stop pin is coupled to the first body.

[0120] Clause 22. A method of making a rocker arm assembly, comprising: constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation; providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly comprises the stop bore and a stop pin, and wherein the stop bore includes a conforming portion associated with the second body such that a radius of curvature of the conforming portion is configured to receive the stop pin; disposing the stop pin in the stop bore and coupling the stop pin to the first body so that the stop mechanism defines a range of relative motion between the first body and the second body; and providing a clearance cut overlapping with at least a portion of the stop bore in the second body, wherein one or more edges of the clearance cut define a limit of allowable travel of the stop pin coupled to the first body during operation of the rocker arm assembly.

[0121] Clause 23. The method of clause 22, further comprising: providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly comprises the latch bore.Miscellaneous

[0122] The foregoing description of the embodiments 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 embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. For example, it is possible that each of the characteristics described in one of the examples of an embodiment can be combined with one or a plurality of other desired characteristics from other embodiments, resulting in other embodiments that may not be described in words or by reference to the drawings, but which are fully contemplated. It will also be understood that changes and modifications may be made by those of ordinary skill within the scope of the disclosure, illustrations, and / or the following claims. Such variations are fully contemplated herein and 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.

[0123] The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and / or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.

[0124] It should be noted that figures provided herein may be illustrated schematically rather than literally or precisely; components and aspects of the figures may not necessarily be to scale. Moreover, while like reference labels or numerals may designate corresponding parts throughout the different views in many cases, like parts may not always be provided with like reference numerals or labels in each view. Further, like parts may not be labeled in every view or figure. Numerical ranges recited in this application should be construed to be inclusive of the end points of the stated ranges. Particular axes, such as one or more rotational, lateral and / or longitudinal axes, which may be omitted herein in some illustrations, should be construed to exist in every illustration or situation where it is referred to, or to which it reasonably corresponds. Directional descriptors or references, such as “top,”“bottom,”“upper,”“lower,”“left,” or “right,” among others, are provided herein for ease of reference and are not limiting of the embodiments disclosed herein, whether in isolation or when assembled or installed.

Examples

Embodiment Construction

[0036]The following examples of certain embodiments are provided to facilitate a better understanding of the present disclosure, and are not to be read to limit or define the scope of the disclosure. In accordance with various embodiments of the present disclosure, various mechanisms, assemblies, arrangements, and methods of operation of switchable rocker arm assemblies are disclosed herein.

[0037]In particular embodiments, an engine may comprise one or more cylinders, wherein each cylinder may be provided with one or more valves, such as for allowing selective fluid exchange. By way of example and not limitation, an engine cylinder may comprise one or more intake valves, and / or one or more exhaust valves. In particular embodiments, the valvetrain of an engine may include devices and systems configured to operate one or more valves of a cylinder. By way of example and not limitation, valve operation parameters such as determination of whether one or more particular valves lift (i.e.,...

PRIORITY

[0001] This application claims the benefit under 35 U.S.C. § 365(c) of International Patent Application No. PCT / IB2024 / 058057, filed 19 Aug. 2024, which claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Ser. No. 63 / 520,450 , filed 18 Aug. 2023, which is incorporated herein by reference.TECHNICAL FIELD

[0002] This disclosure generally relates to engine valvetrain systems, and more particularly to valvetrains with switchable rocker arms.BACKGROUND

[0003] Switchable rocker arm assemblies may include stop mechanisms to control a range of motion possible between components during operation. Stop mechanisms may include features that necessitate complex, time-consuming, and / or expensive processes to manufacture. For example, considerable precision may be required for mutual alignment, machining, and finishing operations of particular features, such as to meet operational tolerance requirements. Some stop mechanism designs may also be associated with undesirable forces and / or torques acting on parts of the stop mechanism, and / or on interfacing surfaces thereof.SUMMARY OF PARTICULAR EMBODIMENTS

[0004] Features, devices, systems, and methods disclosed with reference to particular embodiments described herein can enable means for establishing and / or maintaining improved switching performance and latch lash in valvetrains with switchable rocker arms. The present disclosure includes strategies, systems, and methods to enable and provide for less stringent manufacturing tolerance requirements, improved ease of manufacturing and assembly, lower cost, and / or improved lash and latching performance over the operational life of the valvetrain components and systems.

[0005] In particular embodiments, a rocker arm assembly is disclosed, including: a first body and a second body operatively coupled to the first body, at least one of the first body or the second body configured to be rotatable about a rocker shaft; a latch assembly operable in a first latch state and a second latch state and including a latch bore passing through at least a portion of each of the first body and the second body, wherein the latch assembly is configured to: operatively couple the first body and the second body to prevent relative motion therebetween in the first latch state, and permit relative motion between the first body and the second body in the second latch state; and a stop mechanism including a stop bore and a stop pin disposed in the stop bore, the stop bore configured to pass through at least a portion of each of the first body and the second body, wherein the stop mechanism is configured to operatively constrain a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0006] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop bore of the stop mechanism includes a first portion associated with the second body, wherein a radius of curvature of the first portion is configured based on a radius of curvature of the stop pin. In particular embodiments, which may combine the features of some or all of the above embodiments, one of the first body or the second body includes a valve portion configured to operatively engage with one or more valves. In particular embodiments, which may combine the features of some or all of the above embodiments, one of the first body or the second body includes a cam portion configured to receive a valve lift profile from a cam.

[0007] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop pin is operatively secured to the first body.

[0008] In particular embodiments, which may combine the features of some or all of the above embodiments, one of the first body or the second body includes a forked portion having a first outer portion and a second outer portion configured to axially enclose and support an inner portion of the other of the first body or the second body.

[0009] In particular embodiments, which may combine the features of some or all of the above embodiments, the latch bore is configured to be disposed in at least a portion of each of the first outer portion, the second outer portion, and the inner portion. In particular embodiments, which may combine the features of some or all of the above embodiments, the latch bore passes through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

[0010] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop pin is operatively secured to the first body or the second body. In particular embodiments, which may combine the features of some or all of the above embodiments, the stop bore is configured to be disposed in at least a portion of each of the first outer portion, the second outer portion, and the inner portion. In particular embodiments, which may combine the features of some or all of the above embodiments, the stop pin is operatively secured to the inner portion and configured to extend into one or both of the first outer portion or the second outer portion.

[0011] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop bore further includes a second portion associated with the second body, the second portion configured to prevent over-travel of the first body or the second body during operation of the rocker arm assembly.

[0012] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop bore passes through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

[0013] In particular embodiments, which may combine the features of some or all of the above embodiments, the rocker arm assembly further includes a lost motion assembly operatively coupled to the first body and the second body and configured to selectively absorb at least a portion of the valve lift profile received from the cam. In particular embodiments, which may combine the features of some or all of the above embodiments, the lost motion assembly absorbing the at least a portion of the valve lift profile is associated with operating the latch assembly in the second latch state.

[0014] In particular embodiments, which may combine the features of some or all of the above embodiments, the lost motion assembly is operable within a range including a collapsed position and an extended position. In particular embodiments, which may combine the features of some or all of the above embodiments, the lost motion assembly includes a lost motion spring, wherein the lost motion spring is configured to bias the lost motion assembly toward the extended position.

[0015] In particular embodiments, which may combine the features of some or all of the above embodiments, the stop mechanism includes a stop surface configured to engage the stop pin to prevent an overextension of the lost motion assembly. In particular embodiments, which may combine the features of some or all of the above embodiments, the latch assembly further includes one or more latch pins, wherein the one or more latch pins are hydraulically or electrically actuated to selectively decouple the first body and the second body.

[0016] In particular embodiments, which may combine the features of some or all of the above embodiments, a method of making a rocker arm assembly is disclosed, the method including: constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation; providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly includes the latch bore; providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly includes the stop bore and a stop pin; and disposing the stop pin in the stop bore and coupling the stop pin to the first body or the second body so that the stop mechanism operatively constrains a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0017] In particular embodiments, which may combine the features of some or all of the above embodiments, the latch bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body. In particular embodiments, which may combine the features of some or all of the above embodiments, the stop bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body.

[0018] In particular embodiments, which may combine the features of some or all of the above embodiments, a valvetrain system is disclosed including: a piston disposed in a cylinder; one or more valves associated with the cylinder; a rocker shaft; and a rocker arm assembly configured to be rotatable about the rocker shaft, including: a first body and a second body operatively coupled to the first body, at least one of the first body or the second body configured to be rotatable about the rocker shaft; a latch assembly operable in a first latch state and a second latch state and including a latch bore passing through at least a portion of each of the first body and the second body, wherein the latch assembly is configured to: operatively couple the first body and the second body to prevent relative motion therebetween in the first latch state, and permit relative motion between the first body and the second body in the second latch state; and a stop mechanism including a stop bore and a stop pin disposed in the stop bore, the stop bore configured to pass through at least a portion of each of the first body and the second body, wherein the stop mechanism is configured to operatively constrain a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0019] In particular embodiments, which may combine the features of some or all of the above embodiments, one of the first body or the second body includes a forked portion having a first outer portion and a second outer portion configured to axially enclose and support an inner portion of the other of the first body or the second body, and wherein one or more of the latch bore or the stop bore is configured to pass through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

[0020] In particular embodiments, which may combine the features of some or all of the above embodiments, a method of making a rocker arm assembly is disclosed comprising: constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation; providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly includes the latch bore; providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly includes the stop bore and a stop pin; and disposing the stop pin in the stop bore and coupling the stop pin to one of the first body or the second body so that the stop mechanism operatively constrains a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0021] In particular embodiments, which may combine the features of some or all of the above embodiments, the latch bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body, and the stop bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body.

[0022] In particular embodiments, which may combine the features of some or all of the above embodiments, a method includes providing a conforming portion associated with the stop bore in the second body such that a radius of curvature of the conforming portion is configured to receive the stop pin, wherein the stop pin is coupled to the first body.

[0023] In particular embodiments, which may combine the features of some or all of the above embodiments, a method of making a rocker arm assembly is disclosed, including: constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation; providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly includes the stop bore and a stop pin, and wherein the stop bore includes a conforming portion associated with the second body such that a radius of curvature of the conforming portion is configured to receive the stop pin; disposing the stop pin in the stop bore and coupling the stop pin to the first body so that the stop mechanism defines a range of relative motion between the first body and the second body; and providing a clearance cut overlapping with at least a portion of the stop bore in the second body, wherein one or more edges of the clearance cut define a limit of allowable travel of the stop pin coupled to the first body during operation of the rocker arm assembly.

[0024] In particular embodiments, which may combine the features of some or all of the above embodiments, a method further includes providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly includes the latch bore.BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be described in greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. Other features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following:

[0026] FIG. 1 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments.

[0027] FIG. 2 illustrates a schematic sectioned top view of a rocker arm assembly, according to particular embodiments.

[0028] FIG. 3 illustrates a schematic partially exploded perspective view of a rocker arm assembly, according to particular embodiments.

[0029] FIG. 4 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments, with an inset depicting particular details of an exemplary stop mechanism.

[0030] FIG. 5A illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments, with an inset depicting particular details of an exemplary stop mechanism.

[0031] FIG. 5B illustrates a schematic side view of a rocker arm assembly, according to particular embodiments.

[0032] FIG. 6 illustrates a schematic sectioned top view of a rocker arm assembly, according to particular embodiments.

[0033] FIG. 7 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments.

[0034] FIG. 8 illustrates a schematic sectioned bottom view of a rocker arm assembly, according to particular embodiments.

[0035] FIG. 9 illustrates a schematic partially exploded perspective view of a rocker arm assembly, according to particular embodiments.DESCRIPTION OF EXAMPLE EMBODIMENTS

[0036] The following examples of certain embodiments are provided to facilitate a better understanding of the present disclosure, and are not to be read to limit or define the scope of the disclosure. In accordance with various embodiments of the present disclosure, various mechanisms, assemblies, arrangements, and methods of operation of switchable rocker arm assemblies are disclosed herein.

[0037] In particular embodiments, an engine may comprise one or more cylinders, wherein each cylinder may be provided with one or more valves, such as for allowing selective fluid exchange. By way of example and not limitation, an engine cylinder may comprise one or more intake valves, and / or one or more exhaust valves. In particular embodiments, the valvetrain of an engine may include devices and systems configured to operate one or more valves of a cylinder. By way of example and not limitation, valve operation parameters such as determination of whether one or more particular valves lift (i.e., open) during operation, an extent of such lift, and / or a timing of such lift relative to other indices of engine operation, such as cylinder motion, may be based on thermodynamic considerations and / or desired modes of operation. By way of example and not limitation, it may be desirable for a valve of an engine cylinder to be opened during particular times during engine operation, and closed during other times. By way of example and not limitation, it can be common practice to reference valve timing relative to one or more other indices of engine operation, such as a position or periodic phase of cylinder motion, crankshaft rotation, and / or camshaft rotation. By way of example and not limitation, valve opening may be referenced in terms of an extent of valve lift, such as a height or displacement of valve opening relative to a seated closed position of a valve. By way of example and not limitation, valve lift may be referenced against a suitable periodic phase to convey detailed information about valve timing and / or operation. In particular embodiments, a valve lift profile may comprise time-varying information about valve operation. By way of example and not limitation, a valve lift profile may comprise an extent and / or a sequence of valve lifts and / or valve opening displacements over time, for e.g., associated with one or more portions of an engine cycle. In particular embodiments, a rocker arm assembly receiving motion from a cam may correspond to the rocker arm assembly receiving one or more portions of a valve lift profile associated with the cam.

[0038] In particular embodiments, a valvetrain may comprise valve timing devices and / or systems configured to impart and / or modify valve timing. By way of example and not limitation, valve timing systems may comprise mechanical means, such as one or more camshafts configured to rotate based on engine operation, such as indexed to periodic cylinder motion. By way of example and not limitation, a camshaft may comprise one or more cams configured to provide a geometric representation of a desired extent of valve lift for opening one or more valves of interest based on rotation of a corresponding camshaft. By way of example and not limitation, a cam may include one or more lobes rising above a minimum characteristic dimension, e.g., a base circle, to encode a physical manifestation of a desired time-varying evolution of valve lift displacements comprising a valve lift profile, which may be transferred to a suitable interfacing component via rotation of the cam. In particular embodiments, devices and systems for imparting and / or modifying valve timing may not be cam-based in one or more respects. In particular embodiments, valves may be directly or indirectly operated using actuators with or without employing cams. By way of example and not limitation, hydraulic, electromagnetic, and / or pneumatic actuators may be configured to directly or indirectly operate one or more valves.

[0039] In particular embodiments, a rocker arm assembly of a valvetrain may be configured to receive, transmit, modify, and / or selectively transfer one or more valve lift profiles.

[0040] In particular embodiments, receiving of a valve lift profile by a rocker arm assembly may comprise transfer of a force or motion from a suitable mechanism such as described above, for e.g., a cam, or an electromagnetic actuator. By way of example and not limitation, a received motion associated with receiving a valve lift profile may comprise displacements, translational motion, and / or rotational motion. By way of example and not limitation, receiving of a valve lift profile may comprise receiving no force or motion for some or all portions of an engine cycle, for e.g., due to partial or total loss of contact of a roller with a cam, and / or due to a mode change by design.

[0041] In particular embodiments, a rocker arm assembly may be configured to directly or indirectly receive one or more valve lift profiles. By way of example and not limitation, a rocker arm assembly may be configured to directly receive a valve lift profile from a cam via a suitable mechanism, e.g., based on a time-varying or permanent rotational engagement with a roller mechanism. By way of example and not limitation, a rocker arm assembly may be configured to indirectly receive a valve lift profile from a cam via a suitable mechanism, e.g., a pushrod mechanism. In particular embodiments, a force or motion transfer path between a cam and a rocker arm assembly associated with receiving a valve lift profile may additionally or alternatively comprise one or more intermediate components, e.g., a lash adjustment mechanism.

[0042] In particular embodiments, transmitting of a valve lift profile by a rocker arm assembly may comprise conversion of a force or motion associated with a received valve lift profile to a corresponding force or motion applied at a valve-interfacing portion of the rocker arm assembly. By way of example and not limitation, a rocker arm assembly configured to receive motion corresponding to a valve lift profile received from a cam via a roller mechanism may rotate about a rocker shaft and via such rotation, may transmit the received valve lift profile as a corresponding motion applied by an extended structure at a valve end as a valve lift to one or more valves.

[0043] As will be further described herein, in particular embodiments, a rocker arm assembly may modify and / or selectively transfer a valve lift profile. By way of example and not limitation, a rocker arm assembly may be configured to selectively absorb or transmit some or all parts of a received valve lift profile. By way of example and not limitation, a rocker arm assembly may be configured to selectively combine more than one received valve lift profile.

[0044] In particular embodiments, this disclosure describes features, devices, systems, and / or methods that can allow establishing and / or maintaining improved switching performance and latch lash in valvetrains with switchable rocker arms. In particular embodiments, strategies, systems, and / or methods described herein can provide for less stringent tolerance requirements, improved ease of assembly, reduced cost, and / or improved lash and latching performance over the operational life of the valvetrain components and systems. In particular embodiments, benefits described herein may be realized by processing or co-processing portions of the assembly, such as processing to create interfaces associated with a latching system and a stop mechanism while the rocker arm is fixtured in an assembled configuration. By way of example and not limitation, a latch bore (or latch pin bore) of a latch mechanism may be created in a combined process along with creating a stop bore of a stop mechanism, for e.g., by machining, drilling, reaming or another suitable process, while movable parts of a rocker arm assembled are constrained in an assembled configuration for processing, e.g., by a fixture. In particular embodiments, systems and methods disclosed herein may comprise processing latch bores and / or lash stop interfaces while a plurality of sides of the rocker arms assembly are constrained in their assembled position, for e.g., by fixturing. In particular embodiments, a plurality of latch bores or bore sections, such as across or through a set of rocker arm portions, may be processed to the same diameter. In particular embodiments, one or more portions of a latch bore may be provided with an insert, which can eliminate the need and costs of precision grinding for lash setting.

[0045] In particular embodiments, latch lash may be established with precise, expensive finishing operations, e.g., grinding. In particular embodiments, measurement of latch pins may require sorting into categories, wherein sorted pins may then be matched up with rocker arms according to specific subassembly lash measurements. As will be further described herein, in particular embodiments, relative position(s) of critical features of rocker arm assemblies may be precisely manufactured, processed, assembled, and / or maintained during operation without requiring time consuming and / or expensive operations, such as grinding. By way of example and not limitation, processing or co-processing latch bores and / or stop bores and / or stop surfaces in an assembled configuration of the rocker arm assembly may enable such benefits. By way of example and not limitation, such methods, devices and / or system may allow for reduced lash variation, for e.g., without sizing and / or sorting latch pins according to tolerance bands.

[0046] In particular embodiments, methods, devices, and / or systems such as described in this disclosure may eliminate the need for a bushing in particular pivot structures, such as rocker shaft bores. By way of example and not limitation, with nitride layer on pivot bores, there may be no functional need for a bushing, which may be intended to hold a plurality of rocker arm bodies in place before assembly on a rocker shaft. In particular embodiments, a bushing may require tight tolerances, e.g., diametral tolerances, and / or machining of oil channels, which can increase processing cost and / or time. In particular embodiments described herein, devices associated with stop assemblies and / or latch assemblies, such as stop pins and latch pins, may be employed to hold the assembly prior to engine install, with minimal lash.

[0047] Separately or additionally, by way of example and not limitation, some alternative methods or stop features of holding rocker arm bodies and / or components in position against particular components, e.g., a biasing spring of a lost motion assembly, may cause a nominal torque to act perpendicular to the rocker shaft axis on portions of the rocker arm assembly. Accordingly, precise, time-consuming and / or costly machining of rocker arm assembly features may need to be performed with respect to these and other critical features. In particular embodiments, complex geometry may be required to be included in rocker arm assemblies to overcome the abovementioned challenges, which can require further costly machining operations.

[0048] Separately or additionally, some alternative stop features are not suitable for preventing over-extension of one or more portions of a rocker arm assembly beyond intended design limits, such as due to the action of a lost motion spring. By way of example and not limitation, over-extension may allow an engine valve bridge to be displaced in the event of a critical shift. In particular embodiments, as will be further described herein, particular features of a stop assembly, e.g., stop pin interfacing with a stop bore, and / or provisioning a stop pin clearance feature, may be employed to prevent over-extension and / or other unintended deviation of rocker arm assembly operation from intended design limits, as will be further described herein.

[0049] In particular embodiments, a valvetrain system comprising a rocker arm assembly may enable such functions and benefits as those described herein. While this disclosure may describe particular kinds of valvetrain architectures and / or switchable rocker arm designs to provide a better understanding, it will be appreciated that this disclosure contemplates any suitable valvetrain architecture and / or switchable rocker arm design for performing such functions and / or obtaining such benefits. By way of example and not limitation, systems and methods described herein may be adapted to any suitable valvetrain architecture, such as Types I through V, and any such variations are fully contemplated herein in any suitable combination.

[0050] Systems and methods described herein may be adapted to many kinds of switching mechanisms and / or actuation methods for implementing switchable rocker arm systems and / or switchable lost motion mechanisms. In particular embodiments, hydraulically driven actuation systems described herein by way of non-limiting example may be complemented or replaced by electrically or electromagnetically driven actuation systems, such as using solenoids. In particular embodiments, valve lift profiles may be directly transferred to a rocker arm assembly from a cam, such as via a roller mechanism. In particular embodiments, valve lift profiles may be indirectly transferred to a rocker arm assembly, such as via a pushrod mechanism, and / or via a hydraulic lash adjuster or other mechanism.

[0051] By way of example and not limitation, collapsible and / or extendable systems, capsule based systems, and / or other lost motion mechanisms with or without springs may employed in particular embodiments. By way of example and not limitation, latch mechanisms comprising one or more pins may be employed. In particular embodiments, one or more pins of the latch mechanism employed herein may be respectively biased along one or more directions.

[0052] By way of example and not limitation, systems and methods described herein may be adapted to multiple applications, including different applications than suggested or described herein, that may be provided or enabled by switchable valvetrains, e.g., variable valve timing applications, cylinder deactivation applications, and / or engine braking applications, and such variations are fully contemplated herein in any suitable combination. While particular examples are included for providing the features, functions, and / or supporting the applications disclosed herein, it will be appreciated that any other suitable methods, systems, applications, and combinations thereof are fully contemplated in this disclosure.

[0053] With reference to the figures, FIG. 1 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments. FIG. 2 illustrates a schematic sectioned top view of a rocker arm assembly, according to particular embodiments. FIG. 3 illustrates a schematic partially exploded perspective view of a rocker arm assembly, according to particular embodiments.

[0054] In particular embodiments, a rocker arm assembly 110 may be configured to rotate about a rocker shaft passing through a rocker shaft bore 120. In particular embodiments, rocker arm assembly 110 may comprise a first body 130 and a second body 140 operatively coupled to first body 130.

[0055] In particular embodiments, rocker arm assembly 110 may comprise a valve portion 132 configured to operatively engage with one or more valves. By way of example and not limitation, first body 130 may comprise one or more valve portions, such as valve portion 132 depicted in the figures herein to provide an understanding. In particular embodiments, second body 140 may separately or additionally comprise one or more valve portions, such as valve portion 132, and such embodiments are fully contemplated herein. In particular embodiments, a valve portion 132 of rocker arm assembly 110 may comprise one or more extended structures, such as to respectively engage one or more valves. By way of example and not limitation, an extended structure of a valve portion 132 of rocker arm assembly 110 may comprise a suitable interfacing structure for directly or indirectly engaging a valve, such as via E-foot 135. In particular embodiments, one or more portions of a valve portion 132 may be configured to engage a plurality of valves, such as via a valve bridge. In particular embodiments, a valve portion 132 of rocker arm assembly 110 may comprise one or more switchable assemblies, such as a collapsible and / or extendable capsule assembly.

[0056] In particular embodiments, rocker arm assembly 110 may comprise a cam portion 142 configured to receive one or more valve lift profiles, such as directly or indirectly from one or more cams. By way of example and not limitation, second body 140 may comprise one or more cam portions, such as cam portion 142, depicted in the figures herein to provide an understanding. In particular embodiments, first body 130 may separately or additionally comprise one or more cam portions, such as cam portion 142, and such embodiments are fully contemplated herein. In particular embodiments, cam portion 142 may comprise a roller mechanism, such as roller 150, which may be configured to be directly engageable with a cam.

[0057] In particular embodiments, first body 130 and second body 140 may be symmetrically arranged in a geometric and / or load path and force transfer context. In particular embodiments, first body 130 and second body 140 may be asymmetrically arranged in a geometric and / or force transfer context. In particular embodiments, such as described herein, first body 130 and second body 140 may be arranged such that one body is an inner member, and the other body forms an outer member enclosing and supporting the inner member. In particular embodiments, a portion of one of the first body 130 or second body 140 of rocker arm assembly 110 may be axially enclosed and / or supported by a forked portion of the other of first body 130 or second body 140 rocker arm assembly 110. By way of example and not limitation, such as depicted in at least FIG. 3, first body 130 may comprise a first outer portion 160 and a second outer portion 170 enclosing both sides of an inner portion 180 of second body 140. By way of example and not limitation, suitable arrangements and configurations such as disclosed herein can permit one of the bodies, such as second body 140, to be axially supported from both ends to reduce side-to-side force asymmetries, twist, wobble, and / or latching inconsistencies. Separately or additionally, suitable arrangements and configurations such as disclosed herein may reduce or improve control of operational wear or uneven wear over time. In particular embodiments, such suitable arrangements and configurations can also reduce the overall material and cross-section needed to sustain operational loads, leading to less costly and / or lighter parts. In particular embodiments, first body 130 and second body 140 may be arranged in a side-by-side configuration, such as depicted in FIGS. 7-9 by way of example and not limitation. By way of example and not limitation, suitable arrangements and configurations such as disclosed herein can permit compact and / or light rocker arm assembly 110 capable of meeting challenging packaging constraints and / or weight requirements.

[0058] In particular embodiments, rocker arm assembly 110 may comprise one or more switchable mechanisms. In particular embodiments, one or more switchable mechanisms of rocker arm assembly 110 may be employed to selectively transmit, modify, and / or absorb one or more portions of one or more valve lift profiles received by rocker arm assembly 110. By way of example and not limitation, rocker arm assembly 110 may comprise a latch assembly, such as latch assembly 400. In particular embodiments, latch assembly 400 may comprise a latch bore 410. In particular embodiments, latch bore 410 may comprise a plurality of bore portions disposed across multiple portions of rocker arm assembly 110. In particular embodiments, latch bore 410 may be at least partially disposed in a roller of cam portion 142, such as roller 150.

[0059] In particular embodiments, first body 130 and second body 140 may be configured to be rotatable about one or more of rocker shaft bore 120 and / or latch bore 410. In particular embodiments, such as depicted in FIGS. 7-9 by way of example and not limitation, first body 130 and second body 140 may be additionally or alternatively configured to be rotatable about a pivot axle, such as pivot axle 145.

[0060] In particular embodiments, latch assembly 400 may be operable in one or more states, such as a first latch state and a second latch state. In particular embodiments, in the first latch state, latch assembly 400 may be configured to operatively couple first body 130 and second body 140, for e.g., to prevent relative motion between first body 130 and second body 140. By way of example and not limitation, in the first latch state of latch assembly 400, first body 130 and second body 140 may be coupled to rotate and / or otherwise move as an integral unit, such as corresponding to an overall motion of rocker arm assembly 110 during operation through an engine cycle. In particular embodiments, in the second latch state, latch assembly 400 may be configured to permit relative motion between first body 130 and second body 140, for e.g., to permit one of first body 130 and second body 140 to receive and / or sustain a force or motion without transmitting said force or motion to the other of first body 130 and second body 140.

[0061] By way of example and not limitation, second body 140 when configured with a cam portion 142 may be configured to receive a valve lift profile. In particular embodiments, corresponding to a first latch state of latch assembly 400, second body 140 may be coupled to first body 130 to transmit the received valve lift to first body 130. In particular embodiments, corresponding to a second latch state of latch assembly 400, second body 140 may be decoupled from first body 130 to prevent some or all of the valve lift from transmitting to first body 130.

[0062] In particular embodiments, latch bore 410 may be configured to pass through at least a portion of each of first body 130 and second body 140. By way of example and not limitation, such as depicted in FIG. 8, latch bore 410 may pass through a full cross-sectional thickness of one body and a portion of the cross-sectional thickness of the other body. In particular embodiments, such as depicted in FIGS. 2 and 6 by way of example and not limitation, latch bore 410 may pass through an entire cross-sectional thickness of both the first body 130 and second body 140.

[0063] In particular embodiments, corresponding to particular configurations of rocker arm assembly 110, latch bore 410 may be configured to be disposed in at least a portion of each of the aligning portions, such as each of the outer portions and the inner portions, of first body 130 and second body 140. By way of example and not limitation, such as further depicted in FIGS. 2 and 6, latch bore 410 may be configured to be disposed in at least a portion of each of first outer portion 160, second outer portion 170, and inner portion 180. In particular embodiments, latch bore 410 may be configured to pass through a respective cross-sectional thickness of each of first outer portion 160, second outer portion 170, and inner portion 180.

[0064] In particular embodiments, latch assembly 400 may comprise one or more pins and / or pistons. In particular embodiments, one or more latch pins of latch assembly 400 may be configured to be latchable or unlatchable, such as to selectively transmit a drive valve lift profile received from a cam portion of rocker arm assembly 110, such as cam portion 142. In particular embodiments, as will be further described herein, one or more such pins and / or pistons of latch assembly 400 may be disposed in latch bore 410, such as slidably disposed to be selectively movable within latch bore 410, and such that latch assembly 400 may be operated to switchable couple or decouple first body 130 and second body 140. In particular embodiments, to enable selective latching by latch assembly 400, one or more latch pins may be configured to selectively slide into, protrude into, and / or out of a portion of latch bore 410. In particular embodiments, one or more axial ends of latch bore 410 may comprise a biasing mechanism, such as biasing member 450. By way of example and not limitation, a biasing mechanism may comprise one or more springs. In particular embodiments, a biasing mechanism may separately or additionally comprise one or more optional force transfer and / or support members, such as support end 460 and / or support end 465, by way of non-limiting example.

[0065] In particular embodiments, latch assembly 400 may be hydraulically actuated, such as based on receiving a selectively pressurized hydraulic fluid. Separately or additionally, in particular embodiments, latch assembly 400 may be electrically or electromagnetically actuated, such as by a solenoid.

[0066] In particular embodiments, switchable latch assembly 400 may be actuated from one side of one or more slidable members (e.g., latch pins), or from a plurality of sides. In particular embodiments, actuation may be based on differential action based on relative forces applied from a plurality of sides. By way of example and not limitation, FIG. 3 illustrates a piston 440 that is axially movable downward (in the frame of reference of the figure) when actuated or energized, and / or that is axially restored to the upward when de-actuated or de-energized, for e.g., based on a restoring force applied by biasing member 450. In particular embodiments, piston 440 may be selectively movable or translatable based on selectively pressurizing a chamber, such as based on hydraulic fluid being fed through hydraulic bore 470. In particular embodiments, such as illustrated in FIG. 2, hydraulic bore 470 may be fluidly connected to a controllable pressurized hydraulic fluid source. By way of example and not limitation, a solenoid-based oil control valve (OCV) may be used to selectively pressurize a hydraulic line to latch assembly 400, such as via rocker shaft bore 120 via hydraulic bore 470.

[0067] In particular embodiments, a plurality of actuation means may be provided, for e.g., to provide multiple and / or differential methods of actuating one or more movable elements of latch assembly 400. By way of example and not limitation, FIG. 8 depicts a movable latch pin 430, which may be selectively actuated based on controlling a hydraulic fluid pressure provided via a hydraulic bore 470. Additionally or alternatively, one or more other members, such as depicted by piston 440 in FIG. 8 by way of non-limiting example, may be movable and / or otherwise controllable, individually or in combination. By way of example and not limitation, movable piston 440 in FIG. 8 may be selectively actuated based on controlling a hydraulic fluid pressure fed via a second hydraulic bore 475.

[0068] In particular embodiments, latch assembly 400 may comprise configurations of movable latching members, such as comprising one or more of each of latch pins and / or pistons. By way of example and not limitation, a latch pin may be configured in particular embodiments to movably block or allow relative motion between components, such as by interference. In particular embodiments, a piston may be configured to receive and / or transmit one or more forces to other components of latch assembly 400, such as an actuating force and / or a restoring or biasing force.

[0069] FIG. 4 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments, with an inset depicting particular details of an exemplary stop mechanism. FIG. 5A illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments, with an inset depicting particular details of an exemplary stop mechanism. FIG. 5B illustrates a schematic side view of a rocker arm assembly, according to particular embodiments.

[0070] As will be further described herein, in particular embodiments, latch assembly 400 may comprise one or more stop mechanisms, such as stop mechanism 300. In particular embodiments, stop mechanism 300 may comprise a stop bore 320. In particular embodiments, stop mechanism 300 may comprise a member, such as an extended member formed as a stop pin 330. In particular embodiments, stop pin 330 may be disposed in stop bore 320.

[0071] In particular embodiments, such as depicted in the inset of FIG. 5A, stop bore 320 may comprise a conforming portion 322. By way of example and not limitation, conforming portion 322 may be configured to include one or more characteristic dimensions of stop pin 330, such as a basis in a radius of curvature of stop pin 330. In particular embodiments, a curvature of conforming portion 322 may be configured to receive stop pin 330. In particular embodiments, conforming portion 322 may have a radius of curvature based on, and / or equal to, a radius of curvature of stop bore 320. In particular embodiments, conforming portion 322 may be configured in the form of a scallop. In particular embodiments, conforming portion 322 may permit a stop feature or stop surface for stop pin 330 within stop bore 320. In particular embodiments, conforming portion 322 may allow a greater surface area for interfacing with stop bore 320, with reduced risk of indentations, accelerated, and / or uneven wear. Accordingly, in particular limitation, conforming portion 322 may improve the operational stability and long-term alignment and latch lash control of rocker arm assembly 110. By way of example and not limitation, a scalloped stop surface of conforming portion 322 as a part of stop bore 320 may be configured to mark and / or hold a normal operational position of rocker arm assembly 110 against stop pin 330.

[0072] It will be appreciated that while features of stop mechanism 300 and / or stop pin 330 may be illustrated or discussed in detail with respect to particular embodiments disclosed herein, this disclosure contemplates incorporation of one or more features of stop mechanism 300 and / or stop pin stop pin 330 in any suitable combination or embodiment.

[0073] By way of example and not limitation, FIG. 2 depicts a latch assembly 400 comprising three movable latching members, i.e., latch pin 430, piston 440, and piston 445. In particular embodiments, piston 440 may be configured to act to displace latch pin 430, such as based on receiving an actuating force due a selectively pressurized fluid chamber fed by hydraulic bore 470. In particular embodiments, piston 445 may be configured to act to displace latch pin 430, such as based on providing a restoring or biasing force due to biasing member 450. In particular embodiments, an actuating force due to piston 440 when acted upon by a pressurized fluid may be configured to exceed an effective restoring or biasing force acting on latch pin 430 due to biasing member 450. Accordingly, in particular embodiments, latch assembly 400 may be configured to selectively move latch pin 430 so that the axial ends or limits of latch pin 430 may be aligned in a non-interfering configuration, thereby acting to decouple and allow relative motion between first body 130 and second body 140.

[0074] FIG. 6 illustrates a schematic sectioned top view of a rocker arm assembly, according to particular embodiments.

[0075] By way of example and not limitation, FIG. 6 depicts a latch assembly 400 comprising four movable latching members, i.e., latch pin 430, latch pin 435, piston 440, and piston 445. In particular embodiments, piston 440 and piston 445 may be configured to act to displace latch pin 430 and latch pin 435, respectively, such as based on the pistons receiving an outward directed actuating force by a selectively pressurized fluid chamber fed by hydraulic bore 470. In particular embodiments, piston 440 and piston 445 may be respectively receive a restoring or biasing force due to biasing member 450 and / or biasing member 455, such as via latch pin 430 and latch pin 435, respectively. In particular embodiments, an actuating force due to piston 440 and piston 445 when acted upon by a pressurized fluid may be configured to exceed an effective restoring or biasing force due to biasing member 450 and / or biasing member 455. Accordingly, in particular embodiments, latch assembly 400 may be configured to selectively move latch pin 430 and / or biasing member 455 so that the axial ends or limits of latch pin 430 and / or latch pin 435 may be separately or concurrently aligned in a non-interfering configuration, thereby acting to decouple and allow relative motion between first body 130 and second body 140. In particular embodiments, one or more end supports, such as C-clips or washers, may be provided to support a biasing member or other components of latch assembly 400. By way of example and not limitation, FIG. 6 depicts end support 480 and end support 485 to enclose, support, and / or constrain biasing member 450 and biasing member 455, respectively, of latch assembly 400.

[0076] FIG. 7 illustrates a schematic perspective view of a rocker arm assembly, according to particular embodiments. FIG. 8 illustrates a schematic sectioned bottom view of a rocker arm assembly, according to particular embodiments. FIG. 9 illustrates a schematic partially exploded perspective view of a rocker arm assembly, according to particular embodiments.

[0077] By way of example and not limitation, FIG. 8 depicts a latch assembly 400 comprising two movable latching members, i.e., latch pin 430 and piston 440.

[0078] In particular embodiments, latch assembly 400 as contemplated herein may separately or additionally comprise other kinds of mechanisms, and / or other components than latching pins and / or piston. By way of example and not limitation, extendable and / or collapsible capsule system.

[0079] It will be appreciated that while particular aspects of structure, configuration, operation, and actuation are described herein with reference to specific embodiments of latch assembly 400 to provide a better understanding, this disclosure contemplates any suitable structure, configuration, operation, and / or actuation or suitable combination thereof for latch assembly 400, and in any combination with other structures or features as described herein.

[0080] In particular embodiments, one or more movable latching members, e.g., piston 440 of FIG. 2, may be configured to be switchably actuated or energized, such as via hydraulic pressure and / or action due to a solenoid. In particular embodiments, one or more movable latching members, e.g., piston 445 of FIG. 2, may be configured to provide a biasing force and / or a restoring force. In particular embodiments, one or more movable members of latch assembly 400 may be configured to receive an actuation force from one direction, or one or more of them may be configured to receive actuation force(s) from multiple directions. In particular embodiments, one or more movable members of latch assembly 400 may be configured to receive a restoring and / or biasing force from one direction, or one or more of the movable members may be configured to receive restoring and / or biasing force(s) from multiple directions. In particular embodiments, a plurality of movable members may be configured to move along a same direction when actuation is enabled, and / or when actuation is disabled, wherein the direction for actuation enabled relative to the direction for actuation disabled can be identical or different. In particular embodiments, a plurality of movable members may be configured to move along different directions when actuation is enabled, and / or when actuation is disabled.

[0081] In particular embodiments, rocker arm assembly 110 may comprise a lost motion assembly, such as lost motion assembly 200. In particular embodiments, lost motion assembly 200 may comprise one or more systems configured for absorbing displacement and / or motion. By way of example and not limitation, lost motion assembly 200 may comprise a lost motion spring 210 capable of absorbing a valve lift received from cam portion 142, such as by compressing based on receiving force, displacement, and / or energy associated with a valve lift from a cam. In particular embodiments, lost motion spring 210 may be supported by an optional lost motion support member 220.

[0082] In particular embodiments, lost motion assembly 200 may be secured to and / or supported by one or more connection assemblies connected to portions of rocker arm assembly 110. In particular embodiments, a first connection 230 may operably couple lost motion assembly 200 to a suitable portion of rocker arm assembly 110, such as to first body 130 as a non-limiting example. In particular embodiments, a second connection 240 may operably couple lost motion assembly 200 to another suitable portion of rocker arm assembly 110, such as second body 140 by way of non-limiting example. In particular embodiments, first connection 230 and / or second connection 240 may comprise one or more pivotable couplings to pivotably couple structures, such as described and / or illustrated herein. In particular embodiments, first connection 230 and / or second connection 240 may comprise one or more slots, anchors, or other suitable means for coupling lost motion assembly 200 with one or more remaining portions of rocker arm assembly 110. By way of example and not limitation, a corresponding support slot 235 and / or support slot 245 such as depicted in at least FIGS. 1 and 9 may be employed to couple, connect, and / or support lost motion assembly 200.

[0083] As discussed, while particular features of specific latch mechanisms and / or specific lost motion mechanisms (e.g., latch assembly 400 and lost motion assembly 200, respectively) are described and / or illustrated herein to provide a better understanding, it will be appreciated that other suitable forms and features of mechanisms are fully contemplated in this disclosure. By way of example and not limitation, a switchable assembly to selectively enable or disable operation of lost motion assembly 200 may be disposed in and / or otherwise combined with lost motion assembly 200 in particular embodiments.

[0084] As previously discussed, in particular embodiments, latch assembly 400 latch may comprise one or more stop mechanisms, such as stop mechanism 300. In particular embodiments, such as depicted in FIG. 4 by way of example and not limitation, stop mechanism 300 may comprise one or more extended stop features, such as stop notch 310, configured to constrain a range of potential motion of latch assembly 400, such as a potential relative motion between first body 130 and second body 140. By way of example and not limitation, such an extended stop feature, e.g., stop notch 310, may be configured to engage with a suitable interfering feature, such as stop cutout 315.

[0085] In particular embodiments, such as depicted in at least FIGS. 1, 5A-5B, and 7 by way of example and not limitation, stop mechanism 300 may comprise a stop bore 320 and / or an extended member such as stop pin 330. In particular embodiments, a stop bore 320 of stop mechanism 300 may be configured to pass through at least a portion of each of first body 130 and second body 140.

[0086] In particular embodiments, stop mechanism 300 may be configured to operatively constrain a range of relative motion between first body 130 and second body 140. In particular embodiments, stop pin 330 may be operatively secured to first body 130 or second body 140, for e.g., to constrain motion of stop pin 330 along particular directions such as radially. In particular embodiments, one or more portions of stop bore 320 in the other of first body 130 and second body 140 may be suitably sized to permit stop pin 330, and a portion of rocker arm assembly 110 operatively secured thereto, to traverse within a permissible range of relative motion of first body 130 and second body 140 while constraining or otherwise preventing relative motion thereof beyond permissible ranges, e.g., over-extension. By way of example and not limitation, such as illustrated in at least FIGS. 2 and 3, stop pin 330 may be operatively secured to a portion of second body 140, e.g., inner portion 180, or another suitable portion. Accordingly, in particular embodiments following such a non-limiting example, stop bore 320 may be formed or otherwise configured in one or more portions of the other body, such as first body 130, to permit stop pin 330 operatively secured to second body 140 to move within stop bore 320 to enable a permissible range of relative motion of first body 130 and second body 140 while constraining or otherwise preventing relative motion thereof beyond permissible ranges. In particular embodiments, other benefits of alignment, manufacturing ease and cost, and / or consistent force and torque loading benefits, among others, may be realized.

[0087] In particular embodiments, such as depicted in FIG. 5A by way of example and not limitation, stop bore 320 of stop mechanism 300 may comprise one or more additional features, such as clearance cut 325. In particular embodiments, one or more such additional features, e.g., clearance cut 325, may be provided in one or more portions of whichever of first body 130 or second body 140 is not coupled to stop pin 330. By way of example and not limitation, FIG. 5A depicts clearance cut 325 provided in one or more portions of first body 130, but not in second body 140, wherein stop pin 330 is operatively secured to first body 130. In particular embodiments, a clearance cut such as clearance cut 325 may be machined into one or more portions of first body 130 or second body 140 wherein stop pin 330 is not secured or otherwise operatively constrained. By way of example and not limitation, clearance cut 325 may be machined into both sides of outer arms of first body 130 or second body 140, e.g., first outer portion 160 and / or second outer portion 170, while preserving the critical stop surface from the original hole of stop bore 320. In particular embodiments, clearance cut 325 may have a relatively loose tolerance on one side, but an opposing side of clearance cut 325 may be designed and processed to prevent an over-travel and / or over-extension of one or more portions of rocker arm assembly 110. In particular embodiments, clearance cut 325 may be configured to operatively constrain a relative motion between first body 130 and 140, for e.g., as stop pin 330 may otherwise traverse to contact a portion of an arm of first body 130 or second body 140 (whichever does not have stop pin 330 secured to it), such as if a biasing member of lost motion assembly 200, e.g., lost motion spring 210, is forced to compress more than intended by design. By way of example and not limitation, in particular embodiments corresponding to undesirable operational scenarios, a rocker arm assembly 110 may go into a critical shift, wherein latch pins may shift during valve lift, and / or may lead to unintentional decoupling of first body 130 and second body 140.

[0088] In particular embodiments, clearance cut 325 may be provided based on enlarging a portion of stop bore 320 in first body 130 or second body 140, for e.g., corresponding to whichever of first body 130 or second body 140 does not have stop pin 330 secured to it. In particular embodiments, one or more edges of clearance cut 325 may exceed a normal range of travel associated with operation of rocker arm assembly 110. By way of example and not limitation, one or more edges of clearance cut 325 may define one or more limits of over-travel or over-extension associated with operation of rocker arm assembly 110, such as by operatively constraining a range of motion of first body 130 and second body 140 during operation of rocker arm assembly 110.

[0089] In particular embodiments, a processing of clearance cut 325, e.g., by machining, may be optionally delayed, for e.g., as a separate step after other parts of stop bore 320 have been processed together for maintaining alignment. In particular embodiments, an extent of clearance cut 325 may exceed a normal operational travel of rocker arm assembly 110, such as that associated with a range of motion of lost motion assembly 200. By way of example and not limitation, one or more limits of a greater travel extent of clearance cut 325 than ordinary operational travel may be configured to prevent over-travel and / or over-extension of rocker arm assembly 110.

[0090] By way of example and not limitation, a range of relative motion between first body 130 and second body 140 such as described above may be associated in particular embodiments with a decoupled state of latch assembly 400 permitting such relative motion between first body 130 and second body 140. By way of example and not limitation, as discussed previously, such a decoupled state may be associated with a second latch state of latch assembly 400.

[0091] In particular embodiments, one or more features such as stop bore 320 may be provided, such as by machining or other processing, in at least a portion of each of first body 130 and second body 140 when rocker arm assembly 110 is constrained in an assembled configuration or state. By way of example and not limitation, first body 130 and second body 140 may be held fixtured on rocker shaft bore 120 and / or other indexing features of rocker arm assembly 110, such as one or more of bearing axle bore(s), valve side bore(s) or feature(s), hydraulic lash bore(s), and / or lash screw bore(s). By way of example and not limitation, a single bore may be reamed through both first body 130 and second body 140 for indexing and locating components of latch assembly 400, while first body 130 and second body 140 of rocker arm assembly 110 are held fixtured in the assembled position. By way of example and not limitation, such a method may permit precise location of the relative position of latch pin 430 in both first body 130 and second body 140 in a rapid, precise, and inexpensive way.

[0092] By way of example and not limitation, it may be important for reliable, consistent and / or efficient operation of rocker arm assembly 110 to provide and maintain suitable operational clearances related to movable members of latch assembly 400, such as latch pin clearance 432 for latch pin 430. By way of example and not limitation, a stop mechanism operatively misaligned with latch assembly 400, for e.g. such that suitable clearances are not properly provided or maintained, may cause unreliable operation or premature failure, such as due to contact and / or other interference during operation, and / or due to excessive latching force requirements based on movable member friction with a corresponding bore. Accordingly, particular embodiments require the use of expensive and / or time-consuming operations, e.g., by grinding, to create and precisely refine relative tolerances between various subassemblies of rocker arm assembly 110, for example, latch bore 410 of latch assembly 400 and stop bore 320 of stop mechanism 300.

[0093] In contrast, in particular embodiments contemplated and described herein, a plurality of alignment-sensitive features of rocker arm assembly 110 may be simultaneously or sequentially processed during a single manufacturing or assembly operation, such as wherein first body 130 and second body 140 may be constrained, such as by a fixture. By way of example and not limitation, latch bore 410 of latch assembly 400 and stop bore 320 of stop mechanism 300 may be simultaneously or sequentially processed, e.g., by drilling, reaming, and / or other suitable operation, while first body 130 and second body 140 may be constrained, such as by a fixture assembly.

[0094] By way of example and not limitation, such a method may eliminate the need for expensive and / or time-consuming processing, e.g., comprising grinding, of latch bores, such as to fix deviations of bore size and / or position, which may separately or additionally be exacerbated after heat treatment of rocker arm assembly 110. In particular embodiments, one or pins, such as one or more of stop pins, latch pins, and / or pistons, may be made to one category with a one-size-fits-all strategy. In particular embodiments, lash variation may be accounted for primarily in the controlling a tolerance of a recess on the pins.

[0095] In particular embodiments, one or more sections of latch bore 410 may be respectively created in at least a portion of each of first body 130 and second body 140 by processing, e.g., by reaming, to the same diameter for simple processing. In particular embodiments, one or more movable components of latch assembly 400, e.g., actuation pistons such as piston 440 and / or piston 445, may utilize a smaller bore than latch bore 410. By way of example and not limitation, to install such smaller-than-bore elements such as a piston, a sleeve or insert, e.g., insert 420, may be inserted within latch bore 410. In particular embodiments, insert 420 may be secured within latch bore 410 via a simple, robust mechanism, such as ball 428 depicted in FIG. 6 by way of example and not limitation.

[0096] In particular embodiments, insert 420 may be either secured with a light press fit. In particular embodiments, depicted in FIG. 6 by way of example and not limitation, a suitable member, such as ball 428, may be pressed to plug particular portions of hydraulic bore 470, such as the supply hole interfaces with an external chamfer centered on a sleeve or insert 420. In particular embodiments, if secured with ball 428, a diametral size of insert 420 may be configured to provide a slip fit while limiting hydraulic fluid flow through the clearance. In particular embodiments, such a clearance may also function as an aide to purge oil behind the pistons during the transition to a deenergized or actuator-off state of latch assembly 400.

[0097] In particular embodiments, stop bore 320 of stop mechanism 300 may be separately or additionally processed to be disposed through at least a portion of each of first body 130 and second body 140 when the bodies are constrained in an assembled configuration of rocker arm assembly 110. In particular embodiments, stop bore 320 and latch bore 410 may be co-processed, e.g., processed sequentially or simultaneously during a common operation while first body 130 and second body 140 are constrained in an assembled configuration of rocker arm assembly 110. In particular embodiments, a stop feature, e.g., stop pin 330, may be secured into at least a portion of one or the other of first body 130 or second body 140. By way of example and not limitation, stop pin 330 may be secured to an inner portion, such as inner portion 180. By way of example and not limitation, stop pin 330 may be secured as disclosed using a press fit, and / or other interference fit. By way of example and not limitation, such a secured stop feature, e.g., stop pin 330, may be accordingly configured to engage with the other of first body 130 or second body 140 wherein stop pin 330 is not secured. By way of example and not limitation, stop pin 330 may be configured to engage at one end of stop pin 330 with the other body.

[0098] In particular embodiments, stop pin 330 may be configured to engage with a plurality of arm portions, e.g., two outer portions such as first outer portion 160 and second outer portion 170, at both ends of the pin. Accordingly, in particular embodiments, such a configuration can prevent a torque from acting that may be otherwise imparted by a stop feature that is offset from a corresponding line or plane of action of a force and / or interference, e.g., a line of action of a biasing force of lost motion spring 210. In particular embodiments, precisely but rapidly creating relatively indexed locations (e.g., engageable stop features of stop mechanism 300 and / or latch bore 410 of latch assembly 400) with reference to first body 130 and second body 140, such as by co-processing means discussed herein, may avoid the need for particular structures, features, and / or processes typically needed, and / or may ensure other critical features are relatively positioned correctly and quickly, thereby saving time, cost, and / or complexity associated with the processing, part(s), and / or system. By way of example and not limitation, a bushing that may be required to be pressed into rocker shaft bores of alternative rocker arm assemblies may be avoided based on systems and methods described herein.ClausesClause 1. A rocker arm assembly comprising: a first body and a second body operatively coupled to the first body, at least one of the first body or the second body configured to be rotatable about a rocker shaft; a latch assembly operable in a first latch state and a second latch state and comprising a latch bore passing through at least a portion of each of the first body and the second body, wherein the latch assembly is configured to: operatively couple the first body and the second body to prevent relative motion therebetween in the first latch state, and permit relative motion between the first body and the second body in the second latch state; and a stop mechanism comprising a stop bore and a stop pin disposed in the stop bore, the stop bore configured to pass through at least a portion of each of the first body and the second body, wherein the stop mechanism is configured to operatively constrain a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0100] Clause 2. The rocker arm assembly of clause 1, wherein the stop bore of the stop mechanism comprises a first portion associated with the second body, wherein a radius of curvature of the first portion is configured based on a radius of curvature of the stop pin.

[0101] Clause 3. The rocker arm assembly as in clauses 1 or 2, wherein the stop bore comprises a second portion associated with the second body, the second portion configured to prevent over-travel of the first body or the second body during operation of the rocker arm assembly.

[0102] Clause 4. The rocker arm assembly of clause 3, wherein the second portion of the stop bore is configured to overlap with at least a portion of the stop bore in the second body.

[0103] Clause 5. The rocker arm assembly as in clauses 3 or 4, wherein one or more edges of the second portion define a limit of allowable travel of the stop pin during operation of the rocker arm assembly.

[0104] Clause 6. The rocker arm assembly as in any of clauses 1 to 5, wherein one of the first body or the second body comprises a comprises a cam portion configured to receive a valve lift profile from a cam, and wherein the other of the first body or the second body comprises a valve portion configured to operatively engage with one or more valves.

[0105] Clause 7. The rocker arm assembly as in any of clauses 1 to 6, wherein the stop pin is operatively secured to the first body.

[0106] Clause 8. The rocker arm assembly as in any of clauses 1 to 7, wherein one of the first body or the second body comprises a forked portion having a first outer portion and a second outer portion configured to axially enclose and support an inner portion of the other of the first body or the second body.

[0107] Clause 9. The rocker arm assembly of clause 8, wherein the latch bore is configured to be disposed in at least a portion of each of the first outer portion, the second outer portion, and the inner portion.

[0108] Clause 10. The rocker arm assembly of clause 9, wherein the latch bore passes through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

[0109] Clause 11. The rocker arm assembly of clause 10, wherein the stop bore passes through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

[0110] Clause 12. The rocker arm assembly of clause 6, further comprising a lost motion assembly operatively coupled to the first body and the second body and configured to selectively absorb at least a portion of the valve lift profile received from the cam.

[0111] Clause 13. The rocker arm assembly of clause 12, wherein the lost motion assembly absorbing the at least a portion of the valve lift profile is associated with operating the latch assembly in the second latch state.

[0112] Clause 14. The rocker arm assembly of clause 12, wherein the lost motion assembly is operable within a range comprising a collapsed position and an extended position.

[0113] Clause 15. The rocker arm assembly of clause 14, wherein the lost motion assembly comprises a lost motion spring, and wherein the lost motion spring is configured to bias the lost motion assembly toward the extended position.

[0114] Clause 16. The rocker arm assembly of clause 12, wherein the stop mechanism comprises a stop surface configured to engage the stop pin to prevent an overextension of the lost motion assembly.

[0115] Clause 17. The rocker arm assembly as in any of clauses 1 to 8, wherein the latch assembly further comprises one or more latch pins, wherein the one or more latch pins are hydraulically or electrically actuated to selectively decouple the first body and the second body.

[0116] Clause 18. A method of making a rocker arm assembly, comprising: constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation; providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly comprises the latch bore; providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly comprises the stop bore and a stop pin; and disposing the stop pin in the stop bore and coupling the stop pin to one of the first body or the second body so that the stop mechanism operatively constrains a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

[0117] Clause 19. The method of clause 18, wherein the latch bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body.

[0118] Clause 20. The method as in clauses 18 or 19, wherein the stop bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body.

[0119] Clause 21. The method as in any of clauses 18 to 20, further comprising providing a conforming portion associated with the stop bore in the second body such that a radius of curvature of the conforming portion is configured to receive the stop pin, wherein the stop pin is coupled to the first body.

[0120] Clause 22. A method of making a rocker arm assembly, comprising: constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation; providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly comprises the stop bore and a stop pin, and wherein the stop bore includes a conforming portion associated with the second body such that a radius of curvature of the conforming portion is configured to receive the stop pin; disposing the stop pin in the stop bore and coupling the stop pin to the first body so that the stop mechanism defines a range of relative motion between the first body and the second body; and providing a clearance cut overlapping with at least a portion of the stop bore in the second body, wherein one or more edges of the clearance cut define a limit of allowable travel of the stop pin coupled to the first body during operation of the rocker arm assembly.

[0121] Clause 23. The method of clause 22, further comprising: providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly comprises the latch bore.Miscellaneous

[0122] The foregoing description of the embodiments 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 embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. For example, it is possible that each of the characteristics described in one of the examples of an embodiment can be combined with one or a plurality of other desired characteristics from other embodiments, resulting in other embodiments that may not be described in words or by reference to the drawings, but which are fully contemplated. It will also be understood that changes and modifications may be made by those of ordinary skill within the scope of the disclosure, illustrations, and / or the following claims. Such variations are fully contemplated herein and 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.

[0123] The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and / or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.

[0124] It should be noted that figures provided herein may be illustrated schematically rather than literally or precisely; components and aspects of the figures may not necessarily be to scale. Moreover, while like reference labels or numerals may designate corresponding parts throughout the different views in many cases, like parts may not always be provided with like reference numerals or labels in each view. Further, like parts may not be labeled in every view or figure. Numerical ranges recited in this application should be construed to be inclusive of the end points of the stated ranges. Particular axes, such as one or more rotational, lateral and / or longitudinal axes, which may be omitted herein in some illustrations, should be construed to exist in every illustration or situation where it is referred to, or to which it reasonably corresponds. Directional descriptors or references, such as “top,”“bottom,”“upper,”“lower,”“left,” or “right,” among others, are provided herein for ease of reference and are not limiting of the embodiments disclosed herein, whether in isolation or when assembled or installed.

Examples

Embodiment Construction

[0036]The following examples of certain embodiments are provided to facilitate a better understanding of the present disclosure, and are not to be read to limit or define the scope of the disclosure. In accordance with various embodiments of the present disclosure, various mechanisms, assemblies, arrangements, and methods of operation of switchable rocker arm assemblies are disclosed herein.

[0037]In particular embodiments, an engine may comprise one or more cylinders, wherein each cylinder may be provided with one or more valves, such as for allowing selective fluid exchange. By way of example and not limitation, an engine cylinder may comprise one or more intake valves, and / or one or more exhaust valves. In particular embodiments, the valvetrain of an engine may include devices and systems configured to operate one or more valves of a cylinder. By way of example and not limitation, valve operation parameters such as determination of whether one or more particular valves lift (i.e.,...

Claims

1. A rocker arm assembly comprising:a first body and a second body operatively coupled to the first body, at least one of the first body or the second body configured to be rotatable about a rocker shaft;a latch assembly operable in a first latch state and a second latch state and comprising a latch bore passing through at least a portion of each of the first body and the second body, wherein the latch assembly is configured to:operatively couple the first body and the second body to prevent relative motion therebetween in the first latch state, andpermit relative motion between the first body and the second body in the second latch state; anda stop mechanism comprising a stop bore and a stop pin disposed in the stop bore, the stop bore configured to pass through at least a portion of each of the first body and the second body, wherein the stop mechanism is configured to operatively constrain a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

2. The rocker arm assembly of claim 1, wherein the stop bore of the stop mechanism comprises a first portion associated with the second body, wherein a radius of curvature of the first portion is configured based on a radius of curvature of the stop pin.

3. The rocker arm assembly of claim 2, wherein the stop bore comprises a second portion associated with the second body, the second portion configured to prevent over-travel of the first body or the second body during operation of the rocker arm assembly.

4. The rocker arm assembly of claim 3, wherein the second portion of the stop bore is configured to overlap with at least a portion of the stop bore in the second body.

5. The rocker arm assembly of claim 4, wherein one or more edges of the second portion define a limit of allowable travel of the stop pin during operation of the rocker arm assembly.

6. The rocker arm assembly of claim 1, wherein one of the first body or the second body comprises a comprises a cam portion configured to receive a valve lift profile from a cam, and wherein the other of the first body or the second body comprises a valve portion configured to operatively engage with one or more valves.

7. The rocker arm assembly of claim 1, wherein the stop pin is operatively secured to the first body.

8. The rocker arm assembly of claim 1, wherein one of the first body or the second body comprises a forked portion having a first outer portion and a second outer portion configured to axially enclose and support an inner portion of the other of the first body or the second body.

9. The rocker arm assembly of claim 8, wherein the latch bore is configured to be disposed in at least a portion of each of the first outer portion, the second outer portion, and the inner portion.

10. The rocker arm assembly of claim 9, wherein the latch bore passes through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

11. The rocker arm assembly of claim 10, wherein the stop bore passes through a respective cross-sectional thickness of each of the first outer portion, the second outer portion, and the inner portion.

12. The rocker arm assembly of claim 6, further comprising a lost motion assembly operatively coupled to the first body and the second body and configured to selectively absorb at least a portion of the valve lift profile received from the cam.

13. The rocker arm assembly of claim 12, wherein the stop mechanism comprises a stop surface configured to engage the stop pin to prevent an overextension of the lost motion assembly.

14. The rocker arm assembly of claim 1, wherein the latch assembly further comprises one or more latch pins, wherein the one or more latch pins are hydraulically or electrically actuated to selectively decouple the first body and the second body.

15. A method of making a rocker arm assembly, comprising:constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation;providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly comprises the latch bore;providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly comprises the stop bore and a stop pin; anddisposing the stop pin in the stop bore and coupling the stop pin to one of the first body or the second body so that the stop mechanism operatively constrains a range of the relative motion between the first body and the second body associated with the second latch state of the latch assembly.

16. The method of claim 15, wherein the latch bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body.

17. The method of claim 16, wherein the stop bore is provided to pass through a plurality of cross-sectional portions of at least one of the first body or the second body.

18. The method of claim 15, further comprising providing a conforming portion associated with the stop bore in the second body such that a radius of curvature of the conforming portion is configured to receive the stop pin, wherein the stop pin is coupled to the first body.

19. A method of making a rocker arm assembly, comprising:constraining a first body and a second body of the rocker arm assembly together in an assembled configuration, wherein at least one of the first body or the second body is rotatable about a rocker shaft, and wherein the first body and the second body are operatively coupled during operation;providing, while the rocker arm assembly is constrained in the assembled configuration, a stop bore passing through each of the first body and the second body, wherein a stop mechanism of the rocker arm assembly comprises the stop bore and a stop pin, and wherein the stop bore includes a conforming portion associated with the second body such that a radius of curvature of the conforming portion is configured to receive the stop pin;disposing the stop pin in the stop bore and coupling the stop pin to the first body so that the stop mechanism defines a range of relative motion between the first body and the second body; andproviding a clearance cut overlapping with at least a portion of the stop bore in the second body, wherein one or more edges of the clearance cut define a limit of allowable travel of the stop pin coupled to the first body during operation of the rocker arm assembly.

20. The method of claim 19, further comprising:providing, while the rocker arm assembly is constrained in the assembled configuration, a latch bore passing through each of the first body and the second body so that a latch assembly is operable in a first latch state to operatively couple the first body and the second body to prevent relative motion therebetween and the latch assembly is operable in a second latch state to permit relative motion between the first body and the second body, wherein the latch assembly of the rocker arm assembly comprises the latch bore.

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