Tappet

Patent metadata

Field	Value
Publication number	US-11208923-B2
Application number	US-202117197505-A
Country	US
Kind code	B2
Filing date	Mar 10, 2021
Priority date	Apr 7, 2020
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A hydraulic tappet configured for a valve train of an internal combustion engine is provided. The tappet includes an outer housing, a socket plunger, and a hydraulic lash adjuster assembly. The socket plunger and the hydraulic lash adjuster assembly are disposed within the outer housing. The hydraulic lash adjuster assembly includes an outer casing, a piston, and a check valve assembly. The outer casing is configured with a spherical first end. The hydraulic lash adjuster assembly can include a swivel pad that engages the spherical first end. The piston is at least partially received by an opening in the outer casing. The piston and socket plunger define a first fluid chamber, while the piston and outer casing define a second fluid chamber. The check valve assembly is arranged to fluidly connect the first fluid chamber to the second fluid chamber.

First claim

What is claimed is:

1. A tappet configured for an internal combustion engine, the tappet comprising:
an outer housing configured to be longitudinally displaced by a camshaft;
a blind first longitudinal bore;
a socket plunger disposed within the first longitudinal bore;
a hydraulic lash adjuster assembly disposed within the first longitudinal bore and engaged with the socket plunger, the hydraulic lash adjuster assembly having:
an outer casing with a spherical first end;
a piston disposed at least partially within a second end of the outer casing, the piston and socket plunger defining a first fluid chamber, and the piston and outer casing defining a second fluid chamber; and,
a check valve assembly arranged to fluidly connect the first fluid chamber to the second fluid chamber; and,
a swivel pad including a first side configured to engage the spherical first end so as to form a spherical joint, and a second side configured to engage a bottom end of the list longitudinal bore.

2. The tappet of claim 1 , wherein the outer housing includes a roller configured to directly engage the camshaft.

3. The tappet of claim 1 , wherein the check valve assembly is biased to a closed position.

4. The tappet of claim 1 , wherein the check valve assembly is biased to an open position.

5. The tappet of claim 1 , wherein the outer housing is displaced a first height by the camshaft, the first height equal to a cam lift of the camshaft.

6. The tappet of claim 1 , wherein the outer casing, piston, and socket plunger define a third fluid chamber that is fluidly connected to the first fluid chamber.

7. The tappet of claim 6 , wherein the outer housing comprises at least one radial port configured to connect a hydraulic fluid pressure source to the third fluid chamber.

8. The tappet of claim 1 , wherein the bottom end of the first longitudinal bore is formed in the outer housing.

9. The tappet of claim 1 , wherein the socket plunger fluidly connects the first fluid chamber to a concave landing arranged on the socket plunger.

10. The tappet of claim 9 , wherein the socket plunger includes an axially extending passage and a transverse passage.

11. A tappet configured for an internal combustion engine, the tappet comprising:
an outer housing configured to be longitudinally displaced by a camshaft, the outer housing having a first longitudinal bore;
a socket plunger disposed within the first longitudinal bore;
a hydraulic lash adjuster assembly disposed within the first longitudinal bore and engaged with the socket plunger, the hydraulic lash adjuster assembly having:
an outer casing disposed within the first longitudinal bore, the outer casing including a spherical first end;
a piston configured to adjust a lash in a valve train system, the piston extending from a second end of the outer casing, such that:
the piston and socket plunger define a first fluid chamber; and,
the piston and outer casing define a second fluid chamber;

a check valve assembly arranged to fluidly connect the first fluid chamber to the second fluid chamber; and,
a swivel pad including a first side configured to engage the spherical first end so as to form a spherical joint, and a second side configured to engage a closed bottom end of the first longitudinal bore.

12. The tappet of claim 11 , wherein the socket plunger is configured to engage a pushrod so as to actuate a rocker arm of the internal combustion engine.

13. The tappet of claim 11 , wherein the closed bottom end of the first longitudinal bore is formed in the outer housing.

14. A tappet for an internal combustion engine, the tappet comprising:
a central axis;
an outer housing configured to be longitudinally displaced by a camshaft, the outer housing having a first longitudinal bore;
a socket plunger disposed within the first longitudinal bore; and,
a hydraulic lash adjuster assembly disposed within the first longitudinal bore and engaged with the socket plunger, a first portion of the hydraulic lash adjuster assembly configured to tilt and rotate relative to a remaining portion of the hydraulic lash adjuster assembly;
wherein the first portion is a swivel pad including a concave reception landing configured to engage a spherical end of the remaining portion; and,
wherein the swivel pad is further configured to engage a closed bottom end of the first longitudinal bore.

15. The tappet of claim 14 , wherein the first portion is configured to tilt to an angle of at least three degrees relative to the remaining portion.

16. The tappet of claim 14 , wherein the outer housing includes a roller configured to directly engage the camshaft.

17. The tappet of claim 14 , wherein the socket plunger is configured to engage a pushrod.

18. The tappet of claim 14 , wherein the closed bottom end of the first longitudinal bore is formed in the outer housing.

Assignees

• Schaeffler Technologies Ag

Inventors

• Ahmed Faheem
• Sailer Peter

Classifications

• F01L2001/256

  between cam and push rod · CPC title

• F01L2001/2427

  by means of an hydraulic adjusting device located between cam and push rod · CPC title

• F01L1/245 Primary

  Hydraulic tappets · CPC title

• F01L1/183

  of the boat type · CPC title

• F01L1/146 Primary

  Push-rods · CPC title