Damper oil seal cap with seal protection feature

Patent metadata

Field	Value
Publication number	US-12558934-B2
Application number	US-202318315840-A
Country	US
Kind code	B2
Filing date	May 11, 2023
Priority date	May 11, 2023
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

An improved oil seal cap for use in a shock absorber for a vehicle including an end wall, and aperture extending through the end wall, and a sidewall extending away from the sidewall in a first direction. The end wall includes a first portion and a second portion, wherein the second portion is raised in a second direction opposite the first direction with respect to the first portion, with the second portion forming a ridge. The oil seal cap is inserted into a reserve tube and cooperates with an oil seal to seal off the top of a shock absorber. The ridge of the end wall is at or above the oil seal and protects the oil seal from impacts of a jounce bumper provided on the shock absorber.

First claim

What is claimed is:

1 . A shock absorber for a vehicle comprising:
a pressure tube; a piston rod extending within the pressure tube along a longitudinal axis; a piston assembly slidably fitted in the pressure tube for movement along the longitudinal axis; a reserve tube surrounding the pressure tube, the reserve tube having a reserve tube inner diameter; an oil seal cap coupled to the reserve tube, the oil seal cap comprising:
an end wall comprising an end wall inner surface, an end wall outer surface, a first end wall portion, a second end wall portion, and an aperture extending through the end wall, wherein the first end wall portion includes a first inner annular surface and a first outer annular surface, and the second end wall portion includes a second inner annular surface and a second outer annular surface; and
a circumferential sidewall extending longitudinally from the end wall along the longitudinal axis, wherein the sidewall terminates in a sidewall end surface, wherein the sidewall has a sidewall outer diameter that is equal to or less than the reserve tube inner diameter, and wherein at least a portion of the sidewall is located within the reserve tube;
wherein the first outer annular surface is located a first distance away from the sidewall end surface and the second outer annular surface is located a second distance away from the sidewall end surface, wherein the second distance is greater than the first distance;
wherein the second outer annular surface extends at an angle greater than 90 degrees with respect to the circumferential sidewall;
an oil seal, wherein at least a portion of the oil seal is in contact with the end wall inner surface of the oil seal cap, wherein the oil seal is at or axially offset from the second outer annular surface of the oil seal cap toward the sidewall end surface; and a rod guide, wherein the oil seal is between the rod guide and the oil seal cap.

2 . The shock absorber of claim 1 , wherein the rod guide includes a recessed shoulder, and wherein a portion of the oil seal is in contact with the recessed shoulder.

3 . The shock absorber of claim 1 , wherein the second outer annular surface is parallel to the first outer annular surface.

4 . The shock absorber of claim 1 , wherein the oil seal comprises a seal body having:
a lower annular seal lip engaging the piston rod; an upper annular seal lip engaging the piston rod; and an upper rim contacting the end wall inner surface of the oil seal cap.

5 . The shock absorber of claim 4 , wherein the oil seal cap further comprises an inner transition surface and the upper rim contacts one or more of the first inner annular surface and the inner transition surface.

6 . The shock absorber of claim 4 , wherein the upper annular seal lip does not extend longitudinally above the second outer annular surface of the oil seal cap.

7 . The shock absorber of claim 1 , further comprising a jounce bumper surrounding the piston rod, wherein the second outer annular surface is contacted by the jounce bumper during certain compression strokes of the shock absorber.

8 . The shock absorber of claim 1 , wherein the oil seal cap further comprises one or more projections extending from the end wall toward the sidewall end surface, wherein the one or more projections retain the oil seal in position within the shock absorber.

9 . A shock absorber for a vehicle comprising:
a pressure tube; a piston rod, at least a portion of which extends within the pressure tube along a longitudinal axis; a jounce bumper through which at least a portion of the piston rod extends; a piston assembly slidably fitted in the pressure tube for movement along the longitudinal axis; an oil seal cap, the oil seal cap comprising:
an end wall having an end wall inner surface and an end wall outer surface,
an aperture extending through the end wall; and
a circumferential sidewall extending longitudinally from the end wall in a first direction, wherein a portion of the end wall includes a ridge extending longitudinally in a second direction opposite the first direction, wherein the ridge extends at an angle greater than 90 degrees with respect to the longitudinal axis;
an oil seal in contact with the end wall inner surface, wherein:
the oil seal cap is longitudinally between the jounce bumper and the oil seal;
the oil seal is at or axially offset from the ridge of the oil seal cap in the first direction; and
the ridge prevents the jounce bumper from contacting the oil seal during certain compression strokes of the shock absorber; and
a reserve tube surrounding the pressure tube and wherein at least a portion of the sidewall of the oil seal cap is located within a portion of the reserve tube.

10 . The shock absorber of claim 9 , further comprising a rod guide, wherein the rod guide is in contact with at least a portion of the oil seal opposite the oil seal cap.

11 . The shock absorber of claim 9 , wherein the ridge is perpendicular to the longitudinal axis.

12 . The shock absorber of claim 9 , wherein the ridge has an annular shape around the aperture.

13 . The shock absorber of claim 9 , further comprising a gap between a portion of the oil seal and the ridge of the oil seal cap.

14 . The shock absorber of claim 9 , wherein the oil seal cap cooperates with the oil seal to close the shock absorber, retain the oil seal in a desired position, and protect the oil seal cap from damaging impacts from the jounce bumper.

15 . A shock absorber for a vehicle comprising:
a pressure tube; a piston rod extending within the pressure tube along a longitudinal axis; a piston assembly slidably fitted in the pressure tube for movement along the longitudinal axis; a reserve tube surrounding the pressure tube; an oil seal cap coupled to the reserve tube, the oil seal cap comprising;
an end wall having an end wall inner surface and an end wall outer surface, wherein the end wall inner surface includes a first inner surface and a second inner surface and the end wall outer surface includes a first outer surface and a second outer surface, wherein the second inner surface is a first longitudinal distance away from the first inner surface and the second outer surface is a second longitudinal distance away from the first outer surface;
an aperture extending through the end wall, wherein the piston rod extends through the aperture; and
a circumferential sidewall extending longitudinally from the end wall, wherein at least a portion of the sidewall is received within the reserve tube, and wherein at least a portion of the reserve tube surrounds at least a portion of the sidewall;
an oil seal having a seal body comprising:
a lower annular seal lip surrounding the piston rod;
an upper annular seal lip surrounding the piston rod, wherein the upper annular seal lip is axially positioned between the second outer surface and the second inner surface of the oil seal cap and does not extend longitudinally beyond the second outer surface of the oil seal cap;
an upper rim in contact with the end wall inner surface of the oil seal cap; and
an upper annular surface, wherein there is a gap between the upper annular surface and the second inner surface of the end wall; and
a rod guide in contact with at least a portion of the oil seal, wherein the rod guide is in contact with the pressure tube opposite the oil seal; wherein the oil seal is longitudinally sandwiched between the oil seal cap and the rod guide.

16 . The shock absorber of claim 15 , wherein the second outer surface is parallel to the first outer

Assignees

• Fed Mogul Motorparts Llc

Inventors

• Bender Michael

Classifications

• B60G2202/143

  subjected to compression · CPC title

• B60G2800/162

  Reducing road induced vibrations · CPC title

• B60G2202/32

  The spring being in series with the damper and/or actuator · CPC title

• B60G2206/41

  Dampers · CPC title

• B60G15/06

  and fluid damper · CPC title