ROCKER ARM HAVING OIL RELEASE VALVE THAT OPERATES AS AN ACCUMULATOR

• US 20200131945A1
• Filed: 12/30/2019
• Published: 04/30/2020
• Est. Priority Date: 05/18/2015
• Status: Active Grant

• Current Assignee: Eaton Srl (Eaton Corporation PLC.)
• Original Assignee: Eaton Srl (Eaton Corporation PLC.)
• Inventors: Andrisani, Nicola
• Granted Patent: US 10,871,086 B2
• Time in Patent Office: Days
• CPC Class Codes: F01L 1/18 Rocking arms or levers
• CPC Class Codes: F01L 1/24 by fluid means, e.g. hydraulically
• CPC Class Codes: F01L 13/06 for braking
• CPC Class Codes: F01L 13/065 Compression release engine retarders of the "Jacobs Manufacturing" type
• CPC Class Codes: F01L 2760/003 for switching to compressor action in order to brake
• CPC Class Codes: F01L 9/10 by fluid means, e.g. hydraulic

Abstract

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode can include a rocker shaft and a rocker arm. The rocker shaft can define a pressurized oil supply conduit. The rocker arm can receive the rocker shaft and is configured to rotate around the rocker shaft. The rocker arm can have an oil supply passage defined therein. A valve bridge can engage a first exhaust valve and a second exhaust valve. An accumulator assembly can be disposed in the rocker arm and includes an accumulator piston that translates within the accumulator piston housing between closed and open positions. A predetermined amount of oil is stored in the accumulator assembly.

Claims

1. An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode, the exhaust valve rocker arm assembly comprising:

a rocker shaft that defines a pressurized oil supply conduit;

a rocker arm that receives the rocker shaft and is configured to rotate around the rocker shaft, the rocker arm having an oil supply passage and an accumulator piston housing defined therein;

a valve bridge that engages a first exhaust valve and a second exhaust valve;

a hydraulic lash adjuster assembly disposed on the rocker arm having a first plunger body movable between a first position and a second position, wherein in the first position, the first plunger body extends rigidly for cooperative engagement with the valve bridge;

a check valve disposed on the rocker arm and having an actuator that selectively releases pressure in the hydraulic lash adjuster; and

an accumulator assembly disposed in the rocker arm and including an accumulator piston that translates within the accumulator piston housing between closed and open positions, the accumulator assembly configured to store a predetermined amount of oil when the first plunger body moves toward the first position, wherein the accumulator assembly further comprises;

an accumulator spring that biases the accumulator piston toward the closed position, wherein in the closed position, oil is inhibited from entering the accumulator piston housing, wherein the accumulator assembly further defines a release hole formed in the rocker arm that fluidly connects with the piston housing, wherein oil is released from the piston housing through the release hole upon the accumulator piston translating a predetermined amount.

2. The exhaust valve rocker assembly of claim 1 wherein in the engine braking mode, pressurized oil is communicated through the pressurized oil supply conduit, through the rocker arm oil supply passage and against the actuator such that the first plunger occupies the first position and acts on the valve bridge during rotation of the rocker arm to a first angle opening the first exhaust valve a predetermined distance while the second exhaust valve remains closed.

3. The exhaust valve rocker assembly of claim 1 wherein the hydraulic lash adjuster assembly is at least partially received by a first bore defined on the rocker arm.

4. The exhaust valve rocker assembly of claim 1 wherein the hydraulic lash adjuster assembly further comprises a second plunger body that is at least partially received by the first plunger body, wherein the second plunger body defines a valve seat.

5. The exhaust valve rocker assembly of claim 4 wherein the check valve is disposed between the first and second plunger bodies.

6. The exhaust valve rocker assembly of claim 5 wherein the check valve further comprising a check ball that selectively seats against the valve seat on the second plunger body.

7. The exhaust valve rocker assembly of claim 6 wherein the actuator further comprises a needle having a longitudinal pin portion and a disk portion, wherein in the engine braking mode, pressurized oil acts against the disk portion moving the longitudinal pin portion a distance away from the check ball.

8. The exhaust valve rocker assembly of claim 7 wherein the disk portion of the actuator is received in a second bore defined in the rocker arm, wherein the first and second bores are collinear.

9. The exhaust valve rocker assembly of claim 1 wherein rotation of the rocker arm to a second predetermined angle disconnects the oil supply passage from the pressurized oil supply conduit.

10. The exhaust valve rocker assembly of claim 1, further comprising a spigot disposed on the rocker arm, wherein in the engine braking mode, subsequent to the opening of the first valve the predetermined distance, further rotation of the rocker arm causes the spigot to move the valve bridge and open the second valve while further opening the first valve.

11. The exhaust valve rocker assembly of claim 10 wherein the spigot is configured to slidably translate along a passage defined in the rocker arm prior to moving the valve bridge.

12. An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode, the exhaust valve rocker arm assembly comprising:

a rocker shaft that defines a pressurized oil supply conduit;

a rocker arm that receives the rocker shaft and is configured to rotate around the rocker shaft, the rocker arm having an oil supply passage and an accumulator piston housing defined therein;

a valve bridge that engages a first exhaust valve and a second exhaust valve;

a first plunger body movable between a first position and a second position, wherein in the first position, the first plunger body extends rigidly for cooperative engagement with the valve bridge;

an actuator that selectively releases pressure acting against the first plunger body; and

an accumulator assembly disposed in the rocker arm and including an accumulator piston that translates within the accumulator piston housing between closed and open positions, the accumulator assembly configured to store a predetermined amount of oil when the first plunger body moves toward the first position, wherein the accumulator assembly further comprises;

an accumulator spring that biases the accumulator piston toward the closed position, wherein in the closed position, oil is inhibited from entering the accumulator piston housing, wherein the accumulator assembly further defines a release hole formed in the rocker arm that fluidly connects with the piston housing, wherein oil is released from the piston housing through the release hole upon the accumulator piston translating a predetermined amount.

13. The exhaust valve rocker assembly of claim 12 wherein in the engine braking mode, pressurized oil is communicated through the pressurized oil supply conduit, through the rocker arm oil supply passage and against the actuator such that the first plunger occupies the first position and acts on the valve bridge during rotation of the rocker arm to a first angle opening the first exhaust valve a predetermined distance while the second exhaust valve remains closed.

14. The exhaust valve rocker assembly of claim 12 wherein rotation of the rocker arm to a second predetermined angle disconnects the oil supply passage from the pressurized oil supply circuit.

15. The exhaust valve rocker assembly of claim 12 wherein the rocker shaft further defines a vent channel, and wherein rotation of the rocker arm to a third predetermined angle connects the oil supply passage to the vent channel releasing the oil pressure from the actuator.

16. The exhaust valve rocker assembly of claim 12, further comprising a spigot disposed on the rocker arm, wherein in the engine braking mode, subsequent to the opening of the first valve the predetermined distance, further rotation of the rocker arm causes the spigot to move the valve bridge and open the second valve while further opening the first valve.

17. The exhaust valve rocker assembly of claim 12, further comprising a second plunger body that is at least partially received by the first plunger body, wherein the second plunger body defines a valve seat.

18. The exhaust valve rocker assembly of claim 17 wherein a check valve is disposed between the first and second plunger bodies, the check valve further comprising a check ball that selectively seats against the valve seat on the second plunger body.

19. The exhaust valve rocker assembly of claim 12 wherein the actuator further comprises a needle having a longitudinal pin portion and a disk portion, wherein in the engine braking mode, pressurized oil acts against the disk portion moving the longitudinal pin portion a distance away from the check bal.

20. The exhaust valve rocker assembly of claim 19 wherein the disk portion of the actuator is received in a second bore defined in the rocker arm, wherein the first and second bores are collinear.