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US 5,072,655 AGranted
Pistons for axial piston machines
AssigneeHydromatik GmbH
InventorBernhard Adler
Life of this patent
Estimating the term…
Abstract
A piston for an axial piston machine, comprising a hollow body having an axial cavity into which a filler piece of a material of lower specific gravity than the material of the piston is inserted which at least partially fills said cavity, said filler piece being secured axially in the cavity by a shoulder projecting radially inwards from the hollow body, is to be designed so that with simple construction a stable axial securing of the filler piece is ensured. This is achieved in that the filler piece has a recess arranged between its ends on its outer surface into which the section of the hollow body overlapping the recess is pressed in a form fitting and force locking manner.
Claims22
A piston for an axial piston machine, comprising:
- a piston body forming an axial cavity, and having a given specific gravity;
- and
- a filler material inserted into and at least partially filling said cavity, and having a specific gravity less than said given specific gravity;
- the filler material including
- i) inner and outer opposite axial ends,
- ii) an annular surface extending between said ends, and
- iii) a recess extending inward from said annular surface at a location between said axial ends;
- the piston body including
- i) a tubular sidewall,
- ii) a radially extending surface extending inward from the sidewall, and
- iii) an indented section connected to and radially extending inward from the sidewall, the indented section being pressed into the recess of the filler material to fit in said recess in pressure engagement against filler material to hold said filler material axially in place in the cavity of the piston body.
8 more elements
A piston for an axial piston machine, comprising:
- a piston body forming an axial cavity, and having a given specific gravity;
- and
- a filler material inserted into and at least partially filling said cavity, and having a specific gravity less than said given specific gravity;
- the filler material including
- i) first and second opposite axial ends, and
- ii) an annular surface extending between said ends;
- the piston body including
- i) a tubular sidewall, and
- ii) a radially extending surface extending inward from the sidewall;
- wherein first and second axially spaced apart portions of the tubular sidewall are pressed inward, from outside said sidewall, to deform both the tubular sidewall and the filler material, and to form recesses in the filler material and indented sections in a tubular sidewall, with said indented sections extending into said recesses to secure the filler material axially in the cavity of the piston body.
7 more elements
A piston for an axial piston machine, comprising:
- a piston body defining a piston axis, forming an axial cavity, and having a given specific gravity;
- and
- a filler material inserted into and at least partially filling said cavity, and having a specific gravity less than said given specific gravity;
- the filler material including
- i) inner and outer opposite axial ends,
- ii) an annular surface extending between said ends, and
- iii) a recess extending inward from said annular surface at a location between said axial ends;
- the piston body including
- i) a tubular sidewall,
- ii) a radially extending surface extending inward from the sidewall, and
- iii) an indented section connected to and radially extending inward from the sidewall, the indented section being pressed into the recess of the filler material to fit in said recess in pressure engagement against the filler material to hold the filler material in the cavity of the piston body;
- wherein the recess has a given axial length, and a first transverse plane extends perpendicular to the piston axis, midway along said given axial length;
- and the indented section has a selected axial length, and a second transverse plane extends perpendicular to the piston axis, midway along said selected axial length;
- and
- wherein the second transverse plane is axially offset relative to the first transverse plane, toward said radially extending surface, and the indented section forces the filler material axially against said radially extending surface to help hold the filler material in the cavity of the piston body.
12 more elements
A piston for an axial piston machine, comprising:
- a piston body forming an axial cavity, and having a given specific gravity;
- and
- a filler material inserted into and at least partially filling said cavity, and having a specific gravity less than said given specific gravity;
- the filler material including
- i) inner and outer opposite axial ends,
- ii) an annular surface extending between said ends, and
- iii) a recess extending inward from said annular surface at a location between said axial ends;
- the piston body including
- i) a tubular sidewall,
- ii) a radially extending surface extending inward from the sidewall, and
- iii) an indented section connected to and radially extending inward from the sidewall, the indented section being pressed into the recess of the filler material to fit in said recess in pressure engagement against the filler material to hold the filler material in the cavity of the piston body;
- wherein the tubular sidewall forms a vent opening extending through said sidewall and in fluid communication with the recess to vent air therefrom as the indented section is pressed into the recess.
9 more elements
A piston for an axial piston machine, comprising:
- a piston body forming an axial cavity, and having a given specific gravity;
- and
- a filler material inserted into and at least partially filling said cavity, and having a specific gravity less than said given specific gravity;
- the filler material including
- i) inner and outer opposite axial ends,
- ii) an annular surface extending between said ends, and
- iii) a recess extending inward from said annular surface at a location between said axial ends;
- the piston body including
- i) a tubular sidewall,
- ii) a radially extending surface extending inward from the sidewall, and
- iii) an indented section connected to and radially extending inward from the sidewall, the indented section being pressed into the recess of the filler material to fit in said recess in pressure engagement against the filler material to hold the filler material in the cavity of the piston body;
- wherein the filler material forms
- i) an axial lubricating passage axially extending inward from the outer end of the filler material to conduct a lubricant thereinto, and
- ii) a radial lubricating passage extending outward from the axial lubricating passage and to the recess of the filler material to conduct the lubricant between the axial lubricating passage and said recess.
11 more elements
Dependencies are inferred from the claim text.