Translating roller lifter design for diesel engines

Patent metadata

Field	Value
Publication number	US-9556754-B2
Application number	US-201414559591-A
Country	US
Kind code	B2
Filing date	Dec 3, 2014
Priority date	Dec 3, 2014
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

A valve lifter assembly for an engine may include a valve lifter body, a roller pin mounted in the valve lifter body and having a crowned barrel portion, and a substantially cylindrical roller mounted about the crowned barrel portion of the roller pin. The roller may have a crowned outer surface with a cylindrical center portion having a constant outer diameter equal to a roller maximum outer diameter, and oppositely disposed variable outer diameter outer portions extending outwardly from either side of the cylindrical center portion toward corresponding roller ends of the roller with a roller outer diameter decreasing as the variable outer diameter outer portions extend outwardly from the cylindrical center portion. The valve lifter assembly may further include a clip having engagement surfaces that are machined to have complimentary shapes to corresponding engagement surfaces of the valve lifter body.

First claim

What is claimed is:

1. A valve lifter assembly for an engine, comprising:
a valve lifter body;
a roller pin mounted in the valve lifter body and having a crowned barrel portion; and
a roller substantially cylindrical in shape mounted about the crowned barrel portion of the roller pin, the roller having a crowned outer surface with a cylindrical center portion having a constant outer diameter equal to a roller maximum outer diameter and extending for about a third of a width of the roller, and variable outer diameter outer portions disposed opposite each other and extending outwardly about a third of a width of the roller from either side of the cylindrical center portion toward corresponding roller ends of the roller with a roller outer diameter decreasing as the variable outer diameter outer portions extend outwardly from the cylindrical center portion.

2. The valve lifter assembly according to claim 1 , wherein a barrel outer surface of the crowned barrel portion is curved in cross-section.

3. The valve lifter assembly according to claim 2 , wherein a barrel curvature of the barrel outer surface of the crowned barrel portion is described by a circular arc.

4. The valve lifter assembly according to claim 1 , wherein the roller pin comprises oppositely disposed engagement portions extending outwardly from either side of the crowned barrel portion and engaged by the valve lifter body to retain the roller pin, wherein an engagement portion outer diameter of the engagement portions is greater than a maximum barrel portion outer diameter of the crowned barrel portion.

5. The valve lifter assembly according to claim 4 , wherein the roller pin includes a lubrication channel extending longitudinally in an outer surface of the roller pin substantially entirely across the crowned barrel portion and partially extending across one of the engagement portions from an intersection of the crowned barrel portion with the one of the engagement portions.

6. The valve lifter assembly according to claim 5 , wherein the valve lifter body includes a lubrication passage, and a portion of the one of the engagement portions into which the lubrication channel extends is aligned with the lubrication passage for receipt of a lubricant provided through the lubrication passage.

7. The valve lifter assembly according to claim 1 , wherein the variable outer diameter outer portions of the roller are curved in cross-section.

8. The valve lifter assembly according to claim 1 , wherein the roller outer diameter decreases at an increasing rate as the variable outer diameter outer portions extend outwardly from the cylindrical center portion.

9. The valve lifter assembly according to claim 8 , wherein the roller outer diameter in the variable outer diameter outer portions is described by a circular arc.

10. The valve lifter assembly according to claim 8 , wherein the roller outer diameter decreases according to a logarithmic progression as the variable outer diameter outer portions extend outwardly from the cylindrical center portion.

11. The valve lifter assembly according to claim 1 , comprising a clip having a clip vertical body portion, a pair of curved clip arms extending outwardly from opposite sides of the clip vertical body portion proximate a lower end of the clip vertical body portion and partially encircling the valve lifter body to retain the clip thereon, and a clip hook extending from an upper end of the clip vertical body portion.

12. The valve lifter assembly according to claim 11 , wherein the valve lifter body includes an engagement surface, and the clip vertical body portion includes a clip engagement surface that faces and engages the engagement surface of the valve lifter body when the clip is mounted thereon, wherein the clip engagement surface is machined to have a substantially planar shape that is complimentary to a substantially planar shape of the engagement surface of the valve lifter body.

13. A roller pin for a valve lifter assembly, comprising:
a crowned barrel portion; and
oppositely disposed engagement portions extending outwardly from either side of the crowned barrel portion, wherein an engagement portion outer diameter of the engagement portions is greater than a maximum barrel portion outer diameter of the crowned barrel portion, and
a lubrication channel extending longitudinally in an outer surface of the roller pin substantially entirely across the crowned barrel portion and partially extending across one of the engagement portions.

14. The roller pin according to claim 13 , wherein a barrel outer surface of the crowned barrel portion is curved in cross-section.

15. The roller pin according to claim 14 , wherein a barrel curvature of the barrel outer surface of the crowned barrel portion is described by a circular arc.

16. A roller for a valve lifter assembly, comprising:
an inner surface defining a cylindrical inner bore; and
a crowned outer surface with a cylindrical center portion having a constant outer diameter equal to a roller maximum outer diameter and extending for about a third of a width of the roller, and variable outer diameter outer portions disposed opposite each other and extending outwardly about a third of a width of the roller from either side of the cylindrical center portion toward corresponding roller ends of the roller with a roller outer diameter decreasing as the variable outer diameter outer portions extend outwardly from the cylindrical center portion.

17. The roller according to claim 16 , wherein the variable outer diameter outer portions of the roller are curved in cross-section.

18. The roller according to claim 16 , wherein the roller outer diameter decreases at an increasing rate as the variable outer diameter outer portions extend outwardly from the cylindrical center portion.

19. The roller according to claim 18 , wherein the roller outer diameter decreases according to a logarithmic progression as the variable outer diameter outer portions extend outwardly from the cylindrical center portion.

Assignees

• Caterpillar Inc

Inventors

• Hattiangadi Ashwin Ashok
• Szmania Terrence Lee
• Bush Brenton William

Classifications

• F01L2301/00

  Using particular materials · CPC title

• F01L2307/00

  Preventing the rotation of tappets · CPC title

• F01L1/14 Primary

  Tappets {(hydraulic tappets for automatically adjusting or compensating clearance F01L1/24)}; Push rods · CPC title

• F01L2810/02

  Lubrication · CPC title

• F01L1/146

  Push-rods · CPC title