Accumulator device

Patent metadata

Field	Value
Publication number	US-10330124-B2
Application number	US-201415111203-A
Country	US
Kind code	B2
Filing date	Dec 19, 2014
Priority date	Jan 14, 2014
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A piston accumulator has a dividing piston (22) inside an accumulator housing (2) that separates a chamber (28) containing a working gas, such as nitrogen, from a chamber (26) containing a working fluid, such as hydraulic oil. The dividing piston (22) is longitudinally movably guided in a guide tube (24). The guide tube (24) is arranged inside the accumulator housing (2) and extends at least partially along the housing longitudinal axis (10).

First claim

The invention claimed is:

1. A piston accumulator, comprising:
an accumulator housing having an axial length along a longitudinal axis thereof;
a floating piston in said accumulator housing separating a gas media chamber from a working liquid chamber inside said accumulator housing;
a guide in which said floating piston is movable within said accumulator housing along said longitudinal axis of said accumulator housing, said guide being arranged inside said accumulator housing, extending at least partially along said longitudinal axis and being a hollow tube, said hollow tube having a transverse diameter equal to a transverse diameter of said floating piston and having a length along said longitudinal axis adapted to a length of said accumulator housing along said longitudinal axis allowing said floating piston and said hollow tube to be prefabricated for assembly in said accumulator housing;
only a first axial end of said hollow tube being fastened impermeably and directly to an axially facing axial inside end surface of said accumulator housing with an opposite second axial end of said hollow tube being free of direct attachments, thereby delimiting said working liquid chamber by an inside surface of said hollow tube and an axial end surface of said floating piston, said floating piston being engageable with said hollow tube and parts of said accumulator housing, said parts of said accumulator housing including a first end housing part having said axial inside end surface, said axial inside end surface having a contour conforming to a free frontal outer contour of said floating piston facing said axial inside end surface of said first end housing part, said free frontal contour of said floating piston being convexly shaped to rest against said axial inside end surface of said first end housing part that is concavely shaped when said floating piston reaches an end position thereof in which working liquid is completely displaced from said working liquid chamber; and
a welded joint between said parts of said accumulator housing being over said hollow tube while maintaining a radial distance therefrom.

2. A piston accumulator according to claim 1 wherein
said hollow tube comprises a longitudinal extension along said longitudinal axis to retain said floating piston therein in every possible movement of said floating piston.

3. A piston accumulator according to claim 1 wherein
said hollow tube is cylindrical with a uniform thickness.

4. A piston accumulator according to claim 1 wherein
said accumulator housing and said hollow tube are concentric; and
a radially facing outside surface of said hollow tube being at constant distance from a radial inside surface of said accumulator housing at least in a central part of said accumulator housing.

5. A piston accumulator according to claim 1 wherein
said hollow tube comprises an opposite second axial end extending in a direction of and spaced from a second axial end surface of said accumulator housing, said first and second end surfaces being opposite one another, said end surfaces being concavely curved.

6. A piston accumulator according to claim 1 wherein
said hollow tube terminates in a transition area where a cylindrically shaped central part merges into a hemispherical end part of said accumulator housing.

7. A piston accumulator according to claim 1 wherein
said end of said hollow tube is fastened to said axial inside end surface of said accumulator housing by direct welding thereof.

8. A piston accumulator according to claim 1 wherein
said inside surface of said end housing part that is concavely shaped is entirely located within said guide.

9. A piston accumulator according to claim 1 wherein
said floating piston comprises a second axial piston end surface opposite said free frontal outer contour, said free frontal contour forming a first axial piston end surface, said first and second axial piston end surfaces being spaced along said longitudinal axis by a distance greater than a spacing of said second axial end of said hollow tube from a second end housing part of said accumulator housing opposite said first end housing part along said longitudinal axis.

10. A piston accumulator according to claim 1 wherein
said parts of said accumulator housing consists of a one-piece and unitary cylindrical main housing part extending between said first end housing part and a second end housing part, each of said first and second end housing parts being a unitary, one-piece structure and being cup-shaped.

11. A piston accumulator, comprising:
a hollow accumulator housing having a longitudinal axis, having opposite first and second axial housing ends and having a liquid port in said first housing end;
a hollow guide tube having opposite first and second axial tube ends and extending coaxially to said longitudinal axis, only said first tube end being impermeably and directly fixed to an axially facing and radially extending first end surface of said first housing end about said liquid port, said hollow guide tube having a radially facing outer surface radially spaced from a radially facing inner surface of said accumulator housing, said second axial tube end being a free end unattached directly to said accumulator housing;
a floating piston slidably and sealably movable inside said hollow tube;
a working liquid chamber being in fluid communication with said liquid port and being defined by said first axial housing end surface of said first housing end surrounded by said hollow guide tube, by an axially extending and radially facing inside surface of said hollow guide tube between said first axial housing end surface and a first axial piston end surface of said floating piston facing said first axial housing end surface and by said first axial piston end surface; and
a gas chamber defined by an inside volume of said accumulator housing not taken by said working liquid chamber, said hollow guide tube and said floating piston.

12. A piston accumulator according to claim 11 wherein
said floating piston comprises a second axial piston end surface opposite said first axial piston end surface, said first and second axial piston end surfaces being spaced along said longitudinal axis by a distance greater than a spacing of said second axial tube end from said second axial housing end along said longitudinal axis.

13. A piston accumulator, comprising:
an accumulator housing having an axial length along a longitudinal axis thereof;
a floating piston in said accumulator housing separating a gas media chamber from a working liquid chamber inside said accumulator housing;
a guide in which said floating piston is movable within said accumulator housing along said longitudinal axis of said accumulator housing, said guide being arranged inside said accumulator housing, extending at least partially along said longitudinal axis and being a hollow tube, said hollow tube having a transverse diameter equal to a transverse diameter of said floating piston and having a length along said longitudinal axis adapted to a length of said accumulator housing along said longitudinal axis allowing said floating piston and said hollow tube to be prefabricated for assembly in said accumulator housing; and
an end of said hollow tube being fastened impermeably and directly to an axially facing inside end surface of said accumulator housing, thereby delimiting said working liquid chamber by an inside surface of said hollow tube and an axial end surface of said floating piston, said floating piston being engaged with said hollow tube and being engagable with parts of said accumulator housing, said hollow tube being only connec

Assignees

• Hydac Technology Gmbh

Inventors

• Baltes Herbert
• Kloft Peter

Classifications

• F15B2201/31

  having rigid separating means, e.g. pistons · CPC title

• F15B2201/605

  Assembling or methods for making housings therefor · CPC title

• F15B2201/405

  Housings · CPC title

• F15B1/24 Primary

  with rigid separating means, e.g. pistons · CPC title