Hydraulic capsule for variable valve actuation

Abstract

A rocker arm assembly includes an engine brake pod assembly. The engine brake pod assembly is movable between a retracted position and an extended position to selectively engage a valve bridge to open a first exhaust valve. The engine brake pod assembly includes an outer casing comprising a lower chamber and a plunger, the plunger extending below the outer casing. The engine brake pod assembly further includes a check ball valve assembly located in the lower chamber and configured to selectively allow hydraulic fluid to enter the lower chamber, and an oil channel in fluid communication with the lower chamber configured to direct a flow of hydraulic fluid out of the lower chamber. The engine brake pod assembly further includes a slide valve configured to selectively block the oil channel.

Description

CROSS-REFERENCE TO RELATED REGISTRATIONS

[0001] The present application claims priority over preliminary US application No. 63 / 319,870, filed on March 15, 2022, which is hereby incorporated by reference as if reproduced in its entirety. BACKGROUND

[0002] The present disclosure relates generally to variable valve actuation and in particular to an improved hydraulic capsule for variable valve actuation.

[0003] Internal combustion engines typically use either a mechanical, electrical, or hydromechanical valve actuation system to operate the engine valves. These systems may include a combination of camshafts, rocker arms, and pushrods driven by the rotation of the engine's crankshaft. In a typical valve train assembly used with a compression engine brake, the exhaust valve is actuated by a rocker arm that engages the exhaust valve via a valve bridge. The rocker arm moves in response to a lobe on a rotating camshaft and pushes on the valve bridge, which in turn pushes on the exhaust valve to open it. With existing engine brake cylinders, shock loads and failure of the e and the circlip can occur if they are pressurized during braking. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The following figures serve to illustrate certain aspects of the present disclosure and should not be regarded as exclusive embodiments. The disclosed subject matter may comprise considerable modifications, alterations, combinations, and equivalents in form and function without deviating from the scope of this disclosure. Fig. Figure 1 shows a perspective view of a valve train arrangement with a rocker arm assembly comprising an intake rocker arm assembly and a combined exhaust rocker arm assembly and engine brake rocker arm assembly, according to one or more aspects of the present disclosure. Fig. 2 shows a cross-sectional view of the in Fig. 1 combined rocker arm assembly shown according to one or more aspects of the present disclosure. Fig. Figure 3 shows a cross-sectional view of an engine brake capsule assembly of the combined rocker arm of Fig. 1 in a propulsion mode, according to one or more aspects of the present disclosure. Fig. Figure 4 shows a cross-sectional view of an engine brake capsule assembly of the combined rocker arm of Fig. 1 in an engine braking mode, according to one or more aspects of the present disclosure. Fig. Figures 5A-5E show cross-sectional views of an engine brake capsule assembly of the combined rocker arm assembly of Fig. 1 during the transition from a drive mode to a motor braking mode according to one or more aspects of the present disclosure. DETAILED DESCRIPTION

[0005] Exemplary embodiments of the present invention are described in detail. For the sake of clarity, not all features of a specific embodiment are described in this description. It is understood that numerous implementation-specific decisions may be made during the development of such a specific embodiment in order to achieve the specific implementation goals, which may vary from one implementation to another. Furthermore, it should be emphasized that such development effort can be complex and time-consuming, but is nevertheless a routine measure for those who possess ordinary technical knowledge and have access to the present disclosure.

[0006] Throughout this entire disclosure, a reference sign followed by an alphabetical character refers to a specific instance of an element, and the reference sign on its own refers to the element in general or as a whole. For example, the object "1a" (not shown in the drawings) refers to an instance of a class of objects that can be collectively called objects "1", each of which can be generally called object "1". In the figures and the description, identical numbers are intended to represent identical elements.

[0007] The terms "couple" or "couples" used here are intended to mean either an indirect or a direct connection. Therefore, if a first device is coupled to a second device, this connection can be made through a direct connection, an indirect electrical connection, or a shaft coupling via other devices and connections.

[0008] For a better understanding of the present disclosure, examples of certain embodiments are set forth below. The following examples are in no way intended to limit or define the scope of the disclosure. The embodiments described below with respect to an implementation are not to be understood as limiting.

[0009] With initial reference to the Fig. 1 and Fig. Figure 2 shows a valve train assembly constructed according to an example of the present disclosure and generally designated by reference numeral 10. The valve train assembly 10 utilizes the engine brake and is shown for use in a four-cylinder engine, but the features described here can be used in any valve train assembly that utilizes the engine brake. The valve train assembly 10 can be held in a valve train carrier 12 and may include two rocker arms per cylinder.

[0010] Specifically, each cylinder can comprise an intake valve rocker arm assembly 14, an exhaust rocker arm assembly 16, and an engine brake rocker arm assembly 18. However, as shown, the exhaust valve rocker arm assembly 16 and the engine brake rocker arm assembly 18 can be combined into a single rocker arm and are collectively referred to as a combined exhaust and engine brake rocker arm assembly 20, which works together to control the opening of both exhaust valves. The present disclosure is not limited to such embodiments and may include separate rocker arm assemblies for the exhaust rocker arm assembly 16 and the engine brake rocker arm assembly 18.The intake valve rocker arm assembly 14 can be configured to control the movement of the intake valves, the exhaust valve rocker arm assembly 16 can be configured to control the movement of the exhaust valves in an actuation mode, and the engine brake rocker arm assembly 18 can be configured to act on one of the two exhaust valves in an engine brake mode, as described here.

[0011] A rocker arm shaft 22 can be received by the valve train carrier 12 and enable the rotation of the combined exhaust and engine brake rocker arm assembly 20. As described herein, the rocker arm shaft 22 can supply oil to the assemblies 16 and 18 during operation. A camshaft 24 can have lift profiles or cams configured to rotate the assemblies 16 and 18 to actuate the first and second exhaust valves 26 and 28, as described in more detail herein. Fig. Figure 2 shows, for example, the camshaft 24 with an exhaust lift profile or cam 30 and a brake lift profile or cam 32, each of which can cause the combined rocker arm assembly 20 to operate in a drive mode and an engine brake mode.

[0012] The combined exhaust and engine brake rocker assembly 20 can generally comprise a rocker body 40, a shaft 42, and a roller 44. The rocker body 40 can include an exhaust rocker section 46 and an engine brake section 48. The rocker body 40 can accommodate the rocker shaft 22 and defines a pair of flanges 50 for receiving the shaft 42, such that the roller 44 is at least partially positioned between them. Thus, the shaft 42 can be coupled to the rocker body 40 and accommodate the roller 44, which is configured to engage with the exhaust lift cam 30 or the engine brake cam 32 of the camshaft 24. This engagement of the roller 44 can cause the combined rocker assembly 20 to rotate about the rocker shaft 22 and engage with a valve bridge assembly 52, as described in more detail herein.

[0013] The exhaust valve rocker arm assembly 16 can include the exhaust rocker arm section 46, which defines a bore 54 configured to at least partially accommodate a dead-pass pin assembly 56. When the roller 44 engages with the exhaust stroke profile 30, the exhaust rocker arm section 46 and the dead-pass pin assembly 56 can be rotated downward, causing a downward movement of the valve bridge assembly 52, which engages the first and second exhaust valves 26 and 28, respectively, connected to a cylinder of an engine (not shown). The dead-pass pin assembly 56 can be configured to accommodate any clearance between the dead-pass pin assembly 56 and the valve bridge assembly 52. ​​In the exemplary embodiment, the dead-pass pin assembly 56 can generally include an E-foot 66 configured to engage the valve bridge assembly 52.

[0014] With further reference to Fig. 2. The engine brake lever section 48 can define a bore 110 configured to at least partially accommodate an engine brake capsule assembly 112. When the engine brake stroke profile 32 engages the roller 44, the engine brake rocker arm section 48 and the engine brake capsule assembly 112 can be rotated downwards, causing a downward movement of the valve bridge assembly 52 that engages only the first exhaust valve 26 (i.e., not the valve 28).

[0015] In the exemplary embodiment, the engine brake capsule assembly 112 can be configured to selectively move from a collapsed mode to a rigid mode in order to selectively transmit a cam motion to the first exhaust valve 26 during an engine braking operation (i.e., in engine braking mode). As shown, an E-foot contained in the engine brake capsule assembly 112 can be configured to act against a valve pin 130, which is slidably arranged within the valve bridge assembly 52, the valve pin 130 being configured to transmit force to the first exhaust valve 26.

[0016] Fig. Figures 3-4 show a cross-sectional view of an improved engine brake capsule assembly 300 according to one or more aspects of the present disclosure. Fig. Figure 3 shows the motor brake capsule assembly 300 in a drive mode, and Fig. Figure 4 shows the engine brake capsule assembly 300 in an engine brake mode. The present disclosure describes the use of a combined exhaust and engine brake rocker arm assembly 20 (see Figure 4). Fig. 1-2) with the engine brake capsule assembly 300. In previous embodiments, the engine brake capsule assembly 112 (see Fig. 2) include a Seeger clip located above an actuating pin or latch, whereby shock loading and failure can occur between the pin / latch and the Seeger clip when pressure is applied during an engine braking mode. The present embodiments of the engine brake capsule assembly 300 can eliminate the need for and use of a Seeger clip and / or a pin / latch and reduce the shock loading during operation.

[0017] The engine brake capsule assembly 300 can be configured to transition between a retracted position and an extended position, whereby in the retracted position the engine brake capsule assembly 300 does not engage with a valve bridge (as in the Fig. 2 valve bridge assembly 52) and in the extended position the engine brake capsule assembly 300 can selectively engage in the valve bridge to open the first exhaust valve 26 (see Fig. 2) The engine brake pod assembly 300 can have any suitable size, height, shape, and any combination thereof. Furthermore, the engine brake pod assembly 300 can comprise any suitable materials, such as metals, non-metals, polymers, composites, and any combination thereof.

[0018] The engine brake capsule assembly 300 can comprise an outer housing 302, a plunger 304, a check ball valve 306, an oil channel 308, and a slide valve 310. In embodiments, the outer housing 302 can be located in the bore 110 (see Fig. 2) of the engine brake lever section 48 (see Fig. 2) be arranged. The outer housing 302 can be configured to accommodate and / or contain the components of the engine brake capsule assembly 300. As shown, the outer housing 300 can comprise a lower chamber 312, an upper chamber 314, and a first bore 316. The first bore 316 can be arranged through the outer housing 302 along a horizontal plane, with the lower chamber 312 being located below the first bore 316 and the upper chamber 314 being located above the first bore 316. In embodiments, both the lower chamber 312 and the upper chamber 314 are in fluid communication with the first bore 316. Furthermore, the oil channel 308 can be in fluid communication with at least the lower chamber 312. In one or more embodiments, the oil channel 308 can additionally be in fluid communication with the upper chamber 314 and connect the lower chamber 312 with the upper chamber 314.During operation, the oil channel 308 can be configured to direct a flow of hydraulic fluid from the lower chamber 312 during a transition from the extended position to the retracted position (i.e., from motor brake mode to drive mode).

[0019] The engine brake capsule assembly 300 can further comprise a plug 318 located at one end of the first bore 316 and configured to seal that end, with the opposite end being open and configured to receive a fluid. As shown, the slide valve 310 can be located within the first bore 316 and be capable of moving along a length of the first bore 316. The engine brake capsule assembly 300 can further comprise a spring 320 connected to the plug 318, with the slide valve 310 being located at the opposite end of the spring 320.The slide valve 310 can be operational to exert a force against the spring 320 and compress it, and in the event of a pressure reduction, the spring 320 can be operational to expand and exert a force against the slide valve 310, thereby causing movement of the slide valve 310.

[0020] In embodiments, the first bore 316 can be configured to receive hydraulic fluid supplied by the rocker arm shaft 22 (see Fig. 1-2), wherein the rocker arm shaft is arranged through the combined exhaust and engine brake rocker arm assembly 20. In the present embodiment, the first bore 316 can receive a flow of hydraulic fluid from the upper chamber 314 and through a connecting passage 322, both receiving the hydraulic fluid supplied by the rocker arm shaft 22 through an inlet 324. As shown, the outer housing 302 can further comprise the inlet 324, the inlet 324 being in fluid communication with the upper chamber 314. The connecting passage 322 can be a branching flow path connecting the inlet 324 to the first bore 316. Within the outer casing 302 a central bore 326 can be defined, wherein the central bore 326 is arranged along a central axis 328 of the outer casing 302 and establishes a fluid connection between the upper chamber 314 and the lower chamber 312.In embodiments, the central bore 326 can intersect with the first bore 316 and run parallel to the oil channel 308.

[0021] During operation of the combined exhaust and engine brake rocker arm assembly 20, the engine brake capsule assembly 300 can be actuated to switch between drive mode and engine brake mode. In drive mode, the spring 320 can bias the slide valve 310 into an initial or first position. In the initial position shown, the oil channel 308 is open, and there can be an open fluid connection between the upper chamber 314 and the lower chamber 312 through the oil channel 308. The transition to engine brake mode can involve introducing a flow of hydraulic fluid into the engine brake capsule assembly 300. When hydraulic fluid is introduced into the engine brake capsule assembly 300 via the inlet 324, some of the hydraulic fluid can flow through the connecting passage 322 into the first bore 316.The increasing pressure can force the spool valve 310 to move along the first bore 316 and compress the spring 320 until it rests in a second position. In this second position, the spool valve 310 can block the oil channel 308. The hydraulic fluid can then be directed from the upper chamber 314 through the central bore 326 into the lower chamber 312.

[0022] As shown, the check ball valve 306 can be located on an upper section of the lower chamber 312 and rest at the intersection of the central bore 326 with the lower chamber 312. The check ball valve 306 can be configured to selectively admit hydraulic fluid into the lower chamber to move the plunger 304 from a retracted position to an extended position, with the plunger 304 defining a lower end of the lower chamber 312. During drive mode, the check ball valve 306 can rest at the aforementioned intersection because the fluid connection via the oil channel 308 has been released. Since the oil channel 308 is blocked in engine braking mode, the increased pressure due to the hydraulic fluid can activate the check ball valve 306 and lift it, allowing hydraulic fluid to flow into the lower chamber 312.When the pressure in the lower chamber 312 increases, the plunger 304 can be actuated to move downwards from a retracted position to an extended position. The check ball valve 306 can return to a seated position as soon as there is a negligible pressure difference between the upper and lower chambers 312, 314 and when the plunger 304 engages the first outlet valve 26. For example, when the plunger 304 engages the first outlet valve 26, the reaction force can increase the pressure in the lower chamber 312, thereby closing the check ball valve 306. The operation of the combined exhaust and engine brake rocker arm assembly 20 can now include opening the first exhaust valve 26 with the tappet 304, with the engine brake capsule assembly 300 being able to be in a rigid mode to selectively transmit the cam movement during an engine braking operation to the first exhaust valve 26.

[0023] When the combined exhaust and engine brake rocker arm assembly 20 transitions from engine brake mode back to drive mode, the hydraulic fluid supplied to the engine brake capsule assembly 300 decreases. As the pressure acting on the spool valve 310 decreases, the spring 320 can expand, causing the spool valve 310 to return to its initial first position, thereby opening the oil channel 308. The open oil channel 308 can reduce the pressure in the lower chamber 312 and discharge the pressurized hydraulic fluid from the lower chamber 312, and the plunger 304 can return to a retracted position.

[0024] Fig. Figures 5A-5E show a cross-sectional view of another improved engine brake capsule assembly 500 transitioning from a drive mode to an engine brake mode, according to one or more aspects of the present disclosure. The present disclosure describes the use of a combined exhaust and engine brake rocker arm assembly 20 (see Figure 5A-5E). Fig. 1-2) with the engine brake capsule assembly 500. The engine brake capsule assembly 500 can function similarly to the engine brake capsule assembly 300. Furthermore, the engine brake capsule assembly 500 can comprise the same or similar structures as the engine brake capsule assembly 300. For example, the engine brake capsule assembly 500 can comprise an outer casing 502, a plunger 504, a check ball valve 506, an oil channel 508, a slide valve 510, a spring 512, a plug 514, a lower chamber 516, and a first bore 518. The outer casing 502, the plunger 504, the check ball valve 506, the oil channel 508, the slide valve 510, the spring 512, the plug 514, the lower chamber 516 and the first bore 518 can each operate similarly and / or function like the outer casing 302 (see Fig. 3-4), the pestle 304 (see Fig. 3-4), the check ball valve 306 (see Fig. 3-4), the oil channel 308 (see Fig. 3-4), the slide valve 310 (see Fig. 3-4), the spring 320 (see Fig. 3-4), the plug 318 (see Fig. 3-4), the lower chamber 312 (see Fig. 3-4) and the first borehole 316 (see Fig. 3-4).

[0025] The motor brake capsule assembly 500 can operate without an upper chamber, central bore, connecting passage, or any combination thereof. During operation, hydraulic fluid can be introduced directly into the outer casing 502 via the first bore 518. In drive mode, the spring 512 can be extended, and the spool valve 510 can be positioned in a first position, bearing against a shoulder 520 within the first bore 518. In this first position, the spool valve 510 can block access to the check ball valve 506 in the lower chamber 516. Additionally, the oil channel 508 can be open, providing a fluid connection between the lower chamber 516 and an external component.

[0026] When hydraulic fluid is introduced through the first bore 518 during the transition to an engine braking mode, the spool valve 510 can be actuated to compress the spring 512 and move it along the first bore 518, thereby exposing the check ball valve 506 to the introduced hydraulic fluid. As the pressure increases, the check ball valve 506 can be opened (as shown in Fig. 5C best seen) and allow the introduction of hydraulic fluid into the lower chamber 516. As the pressure in the lower chamber 516 increases, the plunger 504 can be actuated to move from a retracted position to an extended position (best seen in Fig. 5D to be seen). The check ball valve 506 can return to a seated position as soon as there is a negligible pressure difference between the first bore 518 and the lower chamber 516 and when the plunger 504 engages in the first outlet valve 26 (see Fig. 2) For example, when the plunger 504 engages the first outlet valve 26, the reaction force can increase the pressure in the lower chamber 516, thereby closing the check ball valve 506 (as in Fig. 5E best seen). The operation of the combined exhaust and engine brake rocker arm assembly 20 can now include opening the first exhaust valve 26 with the tappet 504, with the engine brake capsule assembly 500 being able to be in a rigid mode to selectively transmit the cam movement during an engine braking operation to the first exhaust valve 26.

[0027] When the combined exhaust and engine brake rocker arm assembly 20 transitions from engine brake mode back to drive mode, the hydraulic fluid supplied to the engine brake capsule assembly 500 decreases. As the pressure acting on the spool valve 510 decreases, the spring 512 can expand, causing the spool valve 510 to move back to its initial first position against the shoulder 520 and thereby opening the oil channel 508. The open oil channel 508 can reduce the pressure in the lower chamber 516 and discharge the pressurized hydraulic fluid from the lower chamber 516, and the plunger 504 can return to a retracted position.

[0028] Therefore, the disclosed systems and methods are well suited to achieving the stated objectives and advantages, as well as their inherent benefits. The specific embodiments disclosed above are merely examples, since the teachings of this disclosure can be modified and implemented in different but equivalent ways, as is obvious to those skilled in the art who have access to the teachings. Furthermore, no limitations are intended on the design or implementation details shown here other than those described in the claims below. It is therefore obvious that the specific exemplary embodiments disclosed above can be altered, combined, or modified, and that all such variations fall within the scope of this disclosure.The systems and methods disclosed herein by way of example can be implemented appropriately without any element not specifically disclosed herein and without any optional element disclosed herein. While compositions and methods described by the terms "comprising," "containing," or "enclosing" various components or steps, the compositions and methods may also consist "essentially of" or "of" the various components and steps. All the numbers and ranges mentioned above can vary by a certain amount. Whenever a range of numbers is specified with a lower bound and an upper bound, every number and every enclosed range that falls within that range is expressly disclosed.In particular, each range of values ​​disclosed herein (in the form "from about a to about b" or equivalently "from approximately a to b" or equivalently "from about") is to be understood as including any number and any range that falls within the broader range of values. Furthermore, the terms in the claims have their simple, ordinary meaning unless expressly and unambiguously defined otherwise by the patent proprietor. Moreover, the indefinite articles "a" or "an" and the like, as used in the claims, are here defined to mean one or more than one of the elements that the article introduces. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 319,870

[0001]

Claims

[1] Rocker arm assembly comprising: a rocker arm including a valve end, the valve end including an actuator bore; and an engine brake capsule assembly in the actuator bore, the engine brake capsule assembly being movable between a retracted position and an extended position, wherein in the retracted position the engine brake capsule assembly does not engage a valve bridge and in the extended position the engine brake capsule assembly selectively engages the valve bridge to open a first exhaust valve, the engine brake capsule assembly comprising: an outer casing comprising a lower chamber; a plunger defining a lower end of the lower chamber, the plunger projecting below the outer housing; a check ball valve assembly disposed in the lower chamber and configured to selectively direct hydraulic fluid into the lower chamber to move the plunger from the retracted position to the extended position; an oil passage in fluid communication with the lower chamber and configured to direct a flow of hydraulic fluid out of the lower chamber during a transition from the extended position to the retracted position; and a spool valve configured to selectively block the oil passage. [2] The rocker arm assembly of claim 1, wherein the outer housing further comprises a first bore disposed along a horizontal plane and configured to receive the hydraulic fluid from a rocker arm shaft, the rocker arm shaft being disposed through a central pivot bore of the rocker arm. [3] The rocker arm assembly of claim 2, wherein the lower chamber is in fluid communication with the first bore, the check ball valve assembly being configured to allow the hydraulic fluid to enter the lower chamber when the hydraulic fluid is introduced into the first bore. [4] The rocker arm assembly of claim 2, wherein the spool valve is disposed in the first bore and coupled to a spring disposed at one end of the first bore. [5] The rocker arm assembly of claim 4, further comprising a plug disposed at the end of the first bore and configured to seal the end of the first bore. [6] The rocker arm assembly of claim 4, wherein the spool valve is configured to compress the spring and translate along the first bore when a flow of hydraulic fluid is introduced into the outer housing. [7] The rocker arm assembly of claim 6, wherein the spool valve is configured to block the oil passage and abut against the end of the first bore when pressure increases due to the introduction of the hydraulic fluid. [8] The rocker arm assembly of claim 7, wherein the spring is configured to extend and move the spool valve back along the first bore when the pressure decreases due to a reduction in the flow of the hydraulic fluid, thereby opening the oil passage to reduce a pressure in the lower chamber. [9] The rocker arm assembly of claim 8, wherein the outer housing further comprises an upper chamber including an inlet, wherein the first bore is disposed between the upper chamber and the lower chamber, and wherein the oil passage fluidly communicates the upper chamber and the lower chamber. [10] The rocker arm assembly of claim 9, wherein the outer housing further comprises a central bore and a connecting passage, the central bore being disposed along a central axis of the outer housing and fluidly connecting the upper chamber to the lower chamber, the connecting passage being disposed between the inlet and the first bore. [11] The rocker arm assembly of claim 10, wherein the inlet is configured to receive the hydraulic fluid from the rocker arm shaft and direct the hydraulic fluid through the connecting passage into the upper chamber and to the first bore. [12] Valve train assembly comprising: a first engine valve; a second engine valve; a valve bridge operatively connected to the first engine valve and the second engine valve; and a combined exhaust and engine brake rocker arm assembly configured to selectively open the first engine valve and the second engine valve, the rocker arm assembly comprising: a rocker arm including a valve end, the valve end including a first actuator bore; and an engine brake capsule assembly in the first actuator bore, the engine brake capsule assembly being movable between a retracted position and an extended position, wherein in the retracted position the engine brake capsule assembly does not engage the valve bridge and in the extended position the engine brake capsule assembly selectively engages the valve bridge to open the first engine valve, the engine brake capsule assembly comprising: an outer casing comprising a lower chamber; a plunger defining a lower end of the lower chamber, the plunger projecting below the outer housing; a check ball valve assembly disposed in the lower chamber and configured to selectively direct hydraulic fluid into the lower chamber to move the plunger from the retracted position to the extended position; an oil passage in fluid communication with the lower chamber and configured to direct a flow of hydraulic fluid out of the lower chamber during a transition from the extended position to the retracted position; and a spool valve configured to selectively block the oil passage. [13] The valve train assembly of claim 12, wherein the outer housing further comprises a first bore disposed along a horizontal plane and configured to receive the hydraulic fluid from a rocker arm shaft, the rocker arm shaft being disposed through a central pivot bore of the rocker arm. [14] The valve train assembly of claim 13, wherein the lower chamber is in fluid communication with the first bore, the check ball valve assembly being configured to allow the hydraulic fluid to enter the lower chamber when the hydraulic fluid is introduced into the first bore. [15] The valve train assembly of claim 13, wherein the spool valve is disposed in the first bore and coupled to a spring disposed at one end of the first bore. [16] The valve train assembly of claim 15, wherein the spool valve is configured to compress the spring and translate along the first bore when a flow of hydraulic fluid is introduced into the outer housing. [17] The valve train assembly of claim 16, wherein the spool valve is configured to block the oil passage and abut the end of the first bore when pressure increases due to the introduction of the hydraulic fluid. [18] The valve train assembly of claim 17, wherein the spring is configured to extend and move the spool valve back along the first bore when the pressure decreases due to a reduction in the flow of the hydraulic fluid, thereby opening the oil passage to reduce a pressure in the lower chamber. [19] The valve train assembly of claim 18, wherein the outer housing further comprises: an upper chamber including an inlet, wherein the first bore is disposed between the upper chamber and the lower chamber, and wherein the oil passage fluidly communicates the upper chamber with the lower chamber; a central hole; and a connecting passage, the central bore being arranged along a central axis of the outer housing and fluidly connecting the upper chamber to the lower chamber, the connecting passage being arranged between the inlet and the first bore. [20] The valve train assembly of claim 19, wherein the inlet is configured to receive the hydraulic fluid from the rocker arm shaft and direct the hydraulic fluid through the connecting passage into the upper chamber and to the first bore.

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