Hydraulic damper with a hydraulic stop arrangement

Patent metadata

Field	Value
Publication number	US-10107352-B2
Application number	US-201715471275-A
Country	US
Kind code	B2
Filing date	Mar 28, 2017
Priority date	Apr 29, 2016
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A hydraulic damper for a motor vehicle including a tube having a main section and a narrowed section. A main piston assembly is disposed inside the main section. A main piston rod is attached to the main piston assembly. A secondary rod is coupled with the main piston rod. A spring seat is disposed about the secondary rod. A spring engages the spring seat and preloads the spring seat. A secondary piston is disposed about and coupled with the secondary rod. The secondary piston has an axial projection and an annular projection that abuts the spring seat. The annular projection defines a plurality of axial slots. A retaining member is fixed to the secondary rod and has an outer face defining a plurality of radial slots. A sealing ring is slidably disposed about the axial projection. An annular channel is defined radially between the sealing ring and the axial projection.

First claim

What is claimed is:

1. A hydraulic damper for a motor vehicle comprising:
a tube extending along an axis and defining a chamber for holding a fluid;
said tube having a main section having a first diameter and a narrowed section having a second diameter being smaller than said first diameter;
a main piston assembly slidably disposed inside said main section of said tube;
a main piston rod attached to said main piston assembly and extending axially outside of said tube;
a secondary rod coupled with and extending axially from said main piston rod;
a spring seat disposed about said secondary rod and axially moveable relative to said secondary rod;
a spring engaging said spring seat and preloading said spring seat in a direction opposite said main piston assembly;
a secondary piston disposed about and coupled with said secondary rod;
said secondary piston having an axial projection and an annular projection, wherein said axial projection extends axially and wherein said annular projection extends radially outwardly relative to said axial portion and abuts said spring seat and defines a plurality of axial slots extending axially therethrough;
a retaining member coupled with said secondary rod on the axially opposite side of said secondary piston as said spring seat and having an outer face defining a plurality of spaced radial slots extending radially inwardly into radial alignment with said axial slots of said secondary piston;
a sealing ring having an external diameter substantially corresponding to the second diameter and disposed about said axial projection axially between said annular projection and said retaining member and axially moveable relative to said axial projection;
an annular channel defined radially between said sealing ring and said axial projection; and
said sealing ring being axially moveable between a first position and a second position, wherein said sealing ring engages said annular projection in said first position to fluidly connect said annular channel with said axial slots of said annular projection, and wherein said sealing ring engages said retaining member in said second position to fluidly connect said annular channel with said radial slots of said retaining member.

2. A hydraulic damper as set forth in claim 1 further including a plurality of annular seats each extending axially from said axial projection and surrounding one of said axial slots.

3. A hydraulic damper as set forth in claim 1 wherein said secondary piston is fixed to said secondary rod.

4. A hydraulic damper as set forth in claim 3 wherein said secondary rod includes a main body portion and an axial extension portion extending axially from said main body portion; wherein said axial extension portion has a smaller diameter than said main body portion; wherein an abutment surface is defined radially between said main body portion and said axial extension portion; and wherein said secondary piston engages said abutment surface.

5. A hydraulic damper as set forth in claim 4 wherein said axial extension portion of said secondary rod presents external threads, and wherein said retaining member is a nut threadedly secured to said external threads of said axial extension portion.

6. A hydraulic damper as set forth in claim 1 further including an annular projection extending radially outwardly from said secondary rod, and wherein said spring engages said annular projection.

7. A hydraulic damper as set forth in claim 1 wherein said hydraulic damper is a twin tube damper.

8. A hydraulic damper as set forth in claim 1 wherein said tube extends axially between a rebound end and a compression end, and wherein said narrowed section of said tube is located at said compression end of the said tube.

9. A hydraulic damper as set forth in claim 8 further including an insert disposed in said compression end of said tube, wherein said insert defines said narrowed section of said tube.

10. A hydraulic damper as set forth in claim 1 wherein said narrowed section of said tube defines at least one slot extending axially.

Assignees

• Beijingwest Ind Co Ltd

Inventors

• Grzesik Radoslaw Pawel
• Flacht Piotr Andrzej

Classifications

• F16F9/3482

  the annular discs being incorporated within the valve or piston body (F16F9/3484, F16F9/3485 take precedence) · CPC title

• F16F9/3257

  in twin-tube type devices · CPC title

• F16F9/3221 Primary

  of piston rods · CPC title

• F16F9/585 Primary

  within the cylinder, in contact with working fluid · CPC title

• F16F9/49 Primary

  Stops limiting fluid passage, e.g. hydraulic stops {or elastomeric elements inside the cylinder which contribute to changes in fluid damping (fluid-actuated displacement devices with means for accelerating or decelerating the stroke F15B15/22)} · CPC title