Hydraulic lash adjuster

Patent metadata

Field	Value
Publication number	US-10082052-B2
Application number	US-201715427865-A
Country	US
Kind code	B2
Filing date	Feb 8, 2017
Priority date	Feb 8, 2017
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

A replaceable hydraulic lash adjuster and method for assembling such are disclosed. The replaceable hydraulic lash adjuster includes a body, a piston, a check valve and a spring. The body configured to be received in and released from a compartment of a rocker arm. The body including a sidewall surrounding a floor. The floor including a passage that extends between an upper cavity and a lower cavity of the body. The piston disposed in the lower cavity. The piston defining a pocket. A check valve is disposed inside the lower cavity and a spring is disposed inside the pocket. The replacable hydraulic lash adjuster is configured to be slidingly removeable from the rocker arm.

First claim

What is claimed is:

1. A replaceable hydraulic lash adjuster for an actuator assembly for an engine valve, the actuator assembly including a rocker arm operatively connected to a valve stem of the engine valve, the rocker arm defining a compartment, the replaceable hydraulic lash adjuster comprising:
a body configured to be slidably received in and slidably released from the compartment of the rocker arm, the body having a top end and a bottom end, the top end of the body configured to be disposed inside the rocker arm, the bottom end of the body configured to be disposed outside of the rocker arm, the body including a sidewall surrounding a floor, the floor disposed below the top end of the body, the sidewall and the floor defining an upper cavity and a lower cavity, the floor including a passage that extends between the upper cavity and the lower cavity, the lower cavity configured to receive a piston, the floor configured to receive a boss that extends through the rocker arm into the upper cavity, wherein the compartment and the upper cavity form an upper chamber when the body is positioned inside the compartment;
the piston including a plunger, a neck and a base, the neck disposed between the base and the plunger, the base disposed inside the lower cavity of the body, the base defining a pocket, the plunger disposed below and outside of the bottom end of the body and configured to be received by a retention member;
a check valve disposed inside the lower cavity and adjacent to the passage and to the base of the piston; and
a spring disposed inside the pocket,
wherein the replacable hydraulic lash adjuster is configured to be slidingly removeable from the compartment of the rocker arm.

2. The replaceable hydraulic lash adjuster of claim 1 , wherein the floor is further configured to form with the boss a fluid pathway to the check valve.

3. The replaceable hydraulic lash adjuster of claim 1 , wherein the rocker arm is cam activated.

4. The replaceable hydraulic lash adjuster of claim 1 , wherein the floor is generally perpendicular to the sidewall.

5. The replaceable hydraulic lash adjuster of claim 1 , wherein the pocket extends in a direction parallel to the sidewall.

6. The replaceable hydraulic lash adjuster of claim 5 , wherein the base is disposed partially outside of the compartment.

7. The replaceable hydraulic lash adjuster of claim 1 further comprising a retaining ring disposed below the base of the piston and mounted to the sidewall inside the lower cavity.

8. The replaceable hydraulic lash adjuster of claim 1 , wherein the plunger has a contact end configured to be received by a recessed surface of the retention member, a shape of the contact end substantially reciprocal to the recessed surface of the retention member.

9. A method of assembling a replaceable hydraulic lash adjuster for an actuator assembly for an engine valve, the actuator assembly including a rocker arm operatively connected to a valve stem of the engine valve, the rocker arm defining a compartment, the method comprising:
providing a body, the body configured to be slidably received in and released from the compartment of the rocker arm, the body having a top end and a bottom end, the top end of the body configured to be disposed inside the compartment, the bottom end of the body configured to be disposed outside of the rocker arm, the body including a sidewall surrounding a floor, the floor disposed below the top end of the body, the sidewall and the floor defining an upper cavity and a lower cavity, the floor including a passage that extends between the upper cavity and the lower cavity, the lower cavity configured to receive a piston, the floor configured to receive a boss that extends through the rocker arm into the upper cavity, wherein the upper cavity is configured to form an upper chamber with the compartment when the body is positioned inside the compartment;
inserting a check valve inside the lower cavity of the body and adjacent to the passage;
providing a piston, the piston including a plunger, a neck and a base, the neck disposed between the base and the plunger, the base defining a pocket; and
disposing a spring inside the piston and inserting the piston into the body,
wherein the hydraulic lash adjuster is disposed between the rocker arm and the engine valve.

10. The method of claim 9 , further including positioning the piston so that the base is disposed inside the lower cavity of the body and the plunger is disposed outside of the bottom end of the body.

11. The method of claim 9 , wherein the floor is generally perpendicular to the sidewall.

12. The method of claim 9 , further including disposing an adjuster O-ring around the sidewall.

13. An actuator assembly for an engine valve that includes a valve stem, the actuator assembly comprising:
a rocker arm that includes:
a first arm end operatively connected to a cam shaft; and
a second arm end defining a compartment configured to receive a replaceable hydraulic lash adjuster and defining a bore extending from an outer surface of the rocker arm to the compartment;

the replaceable hydraulic lash adjuster disposed between the rocker arm and the valve stem, the replaceable hydraulic lash adjuster including:
a body configured to be slidably received in and released from the compartment of the rocker arm, the body having a top end and a bottom end, the top end of the body configured to be disposed inside the rocker arm, the bottom end of the body configured to be disposed outside of the rocker arm and above a retention member, the body including a sidewall surrounding a floor, the floor disposed below the top end of the body, the sidewall and the floor defining an upper cavity and a lower cavity, the floor including a passage that extends between the upper cavity and the lower cavity, the lower cavity configured to receive a piston, the floor configured to receive a boss that extends through the rocker arm into the upper cavity, wherein the compartment and the upper cavity form an upper chamber;
the piston including a plunger, a neck and a base, the neck disposed between the base and the plunger, the base disposed inside the lower cavity of the body, the base defining a pocket, the plunger disposed below and outside of the bottom end of the body and in a recessed surface of the retention member;
a check valve disposed inside the lower cavity and adjacent to the passage and to the base of the piston; and
a spring disposed inside the pocket,
wherein the replacable hydraulic lash adjuster is slidingly removable from the compartment of the rocker;

the boss having an engagement end and a nut end, the boss extending through the bore of the rocker arm into the upper cavity, the engagement end of the boss configured to receive the floor and to adjust, in a direction parallel to the sidewall, a position of the replaceable hydraulic lash adjuster inside the compartment; and
the retention member disposed between the valve stem and the bottom of the body, the retention member including a recessed surface configured to receive the plunger of the piston.

14. The actuator assembly of claim 13 , further comprising a bridge disposed between the retention member and the valve stem of the engine valve.

15. The actuator assembly of claim 13 , in which the boss further a plurality of conduits disposed at the engagement end.

16. The actuator assembly of claim 15 , wherein the floor and each conduit forms a fluid pathway to the passage.

17. The actuator assembly of claim 13 , further including a nut configured to secure the boss to the rocke

Assignees

• Caterpillar Inc

Inventors

• Hattiangadi Ashwin A
• Selvaraj Selvakumar

Classifications

• 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

• F01L2303/00

  Manufacturing of components used in valve arrangements · CPC title

• F01L1/462

  Valve return spring arrangements · CPC title

• F01L1/2416

  by means of a hydraulic adjusting device attached to an articulated rocker · CPC title

• F01L1/053

  overhead type · CPC title