Pressure reservoir in rocker shaft for engine brake

Abstract

Disclosured herein are apparatus and methods relating to combustion engines. In an example, a combustion engine includes a head and a rocker assembly. The rocker assembly including: a rocker shaft including therein a pressure reservoir, a pedestal support adapted to be fastened to the head and sized and structured to support the rocker shaft, a rocker lever pivotally supported by the rocker shaft, and a hydraulic engine brake mechanism within the rocker lever including a hydraulic control valve configured to selectively actuate an exhaust valve of the combustion engine.

We claim: 
     
         1 . A combustion engine comprising:
 a head; and   a rocker assembly including:
 a rocker shaft including therein a pressure reservoir; 
 a pedestal support adapted to be fastened to the head and sized and structured to support the rocker shaft; 
 a rocker lever pivotally supported by the rocker shaft; and 
 a hydraulic engine brake mechanism within the rocker lever including a hydraulic control valve configured to selectively actuate an exhaust valve of the combustion engine. 
   
     
     
         2 . The combustion engine of  claim 1 , wherein the pressure reservoir comprises a reservoir plunger cavity having an inner wall surface and an outer end, a spring, and a reservoir plunger, the spring positioned between the inner wall surface and the outer end and sized and shaped to bias the reservoir plunger toward the inner wall surface in a released state and to allow the reservoir plunger to move toward the outer end in a compressed state. 
     
     
         3 . The combustion engine of  claim 2 , wherein the pressure reservoir is in fluid communication with the hydraulic engine brake mechanism and operable to store fluid under pressure in the compressed state and to release the stored fluid to the hydraulic engine brake mechanism during a transition from the compressed state to the released state responsive to operation of the hydraulic control valve. 
     
     
         4 . The combustion engine of  claim 2 , wherein the reservoir plunger cavity has a longitudinal axis, the rocker shaft further comprising a fastener cavity and a fluid channel fluidly connecting the fastener cavity and the reservoir plunger cavity, wherein the fastener cavity extends perpendicularly to the longitudinal axis of the reservoir plunger cavity and is sized and shaped to receive therethrough a fastener adapted to secure the rocker shaft to the head. 
     
     
         5 . The combustion engine of  claim 4 , wherein the fluid channel has a longitudinal axis that is parallel to and offset from the longitudinal axis of the longitudinal axis of the reservoir plunger cavity. 
     
     
         6 . The combustion engine of  claim 1 , wherein the pedestal support comprises a mounting surface adjacent the head and opposite a shaft support surface, the combustion engine further comprising a valve cover attached to the head to enclose the rocker assembly, wherein a maximum distance from the mounting surface to the valve cover, measured perpendicularly to the mounting surface, is equal to or less than 12.0 cm. 
     
     
         7 . The combustion engine of  claim 1 , wherein the combustion engine has a displacement that is equal to or less than 5.0 liters. 
     
     
         8 . The combustion engine of  claim 7 , further comprising a valve cover attached to the head to enclose the rocker assembly, wherein a maximum distance between the rocker lever and the valve cover is less than 4.0 cm. 
     
     
         9 . A method of making a combustion engine, the method comprising:
 fastening a pedestal support to a head of the combustion engine;   fastening a pressure reservoir inside a rocker lever shaft;   securing the rocker lever shaft to the head; and   mounting a rocker lever onto the rocker lever shaft, the rocker lever including a hydraulic engine brake mechanism having a hydraulic control valve configured to selectively actuate exhaust valves of the combustion engine.   
     
     
         10 . The method of  claim 9 , wherein the pressure reservoir is in fluid communication with the hydraulic engine brake mechanism and operable to store fluid under pressure in a compressed state and to release the stored fluid to the hydraulic engine brake mechanism during a transition from the compressed state to a released state responsive to operation of the hydraulic control valve. 
     
     
         11 . The method of  claim 10 , wherein the pressure reservoir comprises a reservoir plunger cavity having an inner wall surface and an outer end, a spring, and a reservoir plunger, the spring positioned between the inner wall surface and the outer end and sized and shaped to bias the reservoir plunger toward the inner wall surface in the released state and to allow the reservoir plunger to move toward the outer end in the compressed state. 
     
     
         12 . The method of  claim 11 , wherein the rocker lever shaft receives fluid from a fluid source through a first channel. 
     
     
         13 . The method of  claim 12 , wherein the first channel is fluidly coupled with a master piston when the engine braking is engaged so that the master piston and the reservoir plunger move in a coordinated fashion to store and release pressure. 
     
     
         14 . The method of  claim 13 , wherein the master piston includes a second fluid channel that is fluidly coupled with a third fluid channel. 
     
     
         15 . The method of  claim 14 , wherein the second fluid channel is fluidly coupled with the third fluid channel to engage or disengage, via the hydraulic control valve, the engine braking responsive to operation of a solenoid that permits or interrupts fluid flow to engage or disengage the engine braking. 
     
     
         16 . A rocker assembly for a combustion engine, the rocker assembly including:
 a rocker shaft comprising a pressure reservoir;   a pedestal support adapted to be fastened to a head of the combustion engine and sized and structured to support the rocker shaft;   a rocker lever pivotally supported by the rocker shaft; and   a hydraulic engine brake mechanism within the rocker lever including a hydraulic control valve configured to selectively actuate exhaust valves of the combustion engine.   
     
     
         17 . The rocker assembly of  claim 16 , wherein the pressure reservoir is in fluid communication with the hydraulic engine brake mechanism and operable to store fluid under pressure in a compressed state and to release the stored fluid to the hydraulic engine brake mechanism during a transition from the compressed state to a released state responsive to operation of the hydraulic control valve. 
     
     
         18 . The rocker assembly of  claim 16 , wherein the pressure reservoir comprises a reservoir plunger cavity having an inner wall surface and an outer end, a spring, and a reservoir plunger, the spring positioned between the inner wall surface and the outer end and sized and shaped to bias the reservoir plunger toward the inner wall surface in a released state and to allow the reservoir plunger to move toward the outer end in a compressed state. 
     
     
         19 . The rocker assembly of  claim 18 , wherein the reservoir plunger cavity has a longitudinal axis, the rocker shaft further comprising a fastener cavity and a fluid channel fluidly connecting the fastener cavity and the reservoir plunger cavity, wherein the fastener cavity extends perpendicularly to the longitudinal axis of the reservoir plunger cavity and is sized and shaped to receive therethrough a fastener adapted to secure the rocker shaft to the head. 
     
     
         20 . The rocker assembly of  claim 19 , wherein the fluid channel has a longitudinal axis that is parallel to and offset from the longitudinal axis of the longitudinal axis of the reservoir plunger cavity.