Self-retracting hydraulic engine brake system

Patent metadata

Field	Value
Publication number	US-10260386-B2
Application number	US-201615562445-A
Country	US
Kind code	B2
Filing date	Mar 7, 2016
Priority date	Mar 31, 2015
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode includes: a rocker shaft defining a pressurized oil supply conduit; a rocker arm that receives the rocker shaft and rotates around the rocker shaft, the rocker arm having an oil supply passage therein; a valve bridge that engages a first exhaust valve at a first foot and a second exhaust valve at a second foot; and a capsule assembly disposed on the rocker arm having a capsule body that moves between first and second capsule positions, wherein, in the first capsule position, the capsule body is in a retracted position in the rocker arm offset from the valve bridge, wherein, in the second capsule position, the capsule body extends rigidly for cooperative engagement with the valve bridge.

First claim

What is claimed is:

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 defined therein;
a valve bridge that engages a first exhaust valve at a first foot and a second exhaust valve at a second foot;
a capsule assembly disposed on the rocker arm having a capsule body that is configured to move between a first capsule position and a second capsule position, wherein, in the first capsule position, the capsule body is in a retracted position in the rocker arm offset from the valve bridge, wherein, in the second capsule position, the capsule body extends rigidly for cooperative engagement with the valve bridge;
a pulling spring configured to normally bias the capsule body to the retracted position; and
a shift assembly disposed in the capsule assembly and having a shift body configured to move between first and second shift positions, the first shift position corresponding to the capsule body in the first capsule position, the shift body having a shift body chamber that houses a check ball valve assembly, the shift body configured to move from the first shift position to the second shift position in engine brake mode upon opening of the check ball valve assembly,
wherein, in the engine braking mode, pressurized oil is communicated through the oil supply passage and against the shift body such that the shift body moves from the first shift position to the second shift position.

2. The exhaust valve rocker arm assembly of claim 1 , wherein the capsule body extends between a capsule ball end and a stem end, the capsule body defining a shift assembly pocket that receives the shift assembly therein.

3. The exhaust valve rocker arm of claim 2 , wherein the capsule body further defines (i) a capsule channel that extends from the shift assembly pocket to an outer surface of the capsule body, and (ii) a capsule ball end passage that extends from the shift assembly pocket to an outer surface of the capsule body.

4. The exhaust valve rocker arm of claim 3 , wherein the check ball valve assembly includes a check hail and a check valve spring, wherein the check ball is configured to be urged against a valve seat surface provided around a port on the shift body by the check valve spring.

5. The exhaust valve rocker arm of claim 4 , wherein, upon opening of the check ball assembly, the check ball is configured to be moved off of the valve seat such that oil flows through the port and into the capsule channel and the capsule ball end passage.

6. The exhaust valve rocker arm of claim 5 , wherein oil pressure acting on an outer surface of the shift body proximate the port urges the shift body to move from the first shift position to the second shift position.

7. The exhaust valve rocker arm of claim 3 , wherein the capsule body further defines a leakage channel that extends from the shift assembly pocket to an outer surface of the capsule body.

8. The exhaust valve rocker arm of claim 7 , wherein, when the shift body is in the first shift position, low pressure oil acting in the shift body chamber exits through the leakage channel.

9. The exhaust valve rocker arm of claim 1 , further comprising a spigot assembly having a spigot body that extends through a passage firmed through the rocker arm, wherein the spigot body is biased into engagement with the valve bridge and is permitted to translate along an axis thereof within the passage.

10. 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 defined therein;
a valve bridge that engages a first exhaust valve at a first foot and a second exhaust valve at a second foot;
a capsule assembly disposed on the rocker arm having a capsule body that is configured to move between a first capsule position and a second capsule position, wherein, in the first capsule position, the capsule body is in a normally retracted position in the rocker arm offset from the valve bridge, wherein, in the second capsule position, the capsule body extends rigidly for cooperative engagement with the valve bridge; and
a shift assembly disposed in the capsule assembly and comprising:
a shift body configured to move between first and second shift positions, the first shift position corresponding to the capsule body in the first capsule position, the shift body having a shift body chamber;
a check ball valve assembly received in the shift body chamber, the shift body configured to move from the first shift position to the second shift position in engine brake mode upon opening of the check ball valve assembly; and
a return spring configured to bias the shift body toward the first shift position,

wherein, in the engine braking mode, pressurized oil is communicated through the oil supply passage and against the shift body such that the shift body moves from the first shift position to the second shift position.

11. The exhaust valve rocker arm assembly of claim 10 , further comprising:
a pulling spring configured to normally bias the capsule body to the retracted position.

12. The exhaust valve rocker arm assembly of claim 10 , wherein the capsule body extends between a capsule ball end and a stem end, the capsule body defining a shift assembly pocket that receives the shift assembly therein.

13. The exhaust valve rocker arm of claim 12 , wherein the capsule body further defines (i) a capsule channel that extends from the shift assembly pocket to an outer surface of the capsule body, and (ii) a capsule ball end passage that extends from the shift assembly pocket to an outer surface of the capsule body.

14. The exhaust valve rocker arm of claim 13 , wherein the check ball valve assembly includes a check ball and a check valve spring, wherein the check ball is configured to be urged against a valve seat surface provided around a port on the shift body by the check valve spring.

15. The exhaust valve rocker arm of claim 14 , wherein the shift body defines a shift body recirculation groove that leads to a first passage and a second passage extending into the shift body chamber, wherein the capsule channel, the first passage, the second passage, and the capsule ball end passage are all fluidly connected.

16. The exhaust valve rocker arm of claim 15 , wherein oil pressure acting on an outer surface of the shift body proximate the port urges the shift body to move from the first shift position to the second shift position, wherein upon opening of the check ball assembly, the check ball is configured to be moved off of the valve seat such that oil flows through the port and into the capsule channel and the capsule ball end passage.

17. The exhaust valve rocker arm of claim 13 , wherein the capsule body further defines a leakage channel that extends from the shift assembly pocket to an outer surface of the capsule body.

18. The exhaust valve rocker arm of claim 17 , wherein, when the shift body is in the first shift position, low pressure oil acting in the shift body chamber exits through the leakage channel.

19. The exhaust valve rocker arm of clai

Assignees

• Eaton Srl
• Eaton Intelligent Power Ltd

Inventors

• Andrisani Nicola
• Courtial Alessio

Classifications

• F01L13/06 Primary

  for braking · CPC title

• F01L1/18

  Rocking arms or levers · CPC title

• F01L1/26

  characterised by the provision of two or more valves operated simultaneously by same transmitting-gear; peculiar to machines or engines with more than two lift-valves per cylinder (with coaxial valves F01L1/28) · CPC title

• F01L13/065 Primary

  Compression release engine retarders of the "Jacobs Manufacturing" type · CPC title

• F02D13/04

  using engine as brake · CPC title