# US 5,699,715 A · Piston for a reciprocating piston machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,699,715 A - Document ID: US5699715A - Status: Granted - Kind: A - Application number: 08/681,271 - Filed: 1996-07-22 - Granted: 1997-12-23 - Earliest claimed: 1995-07-28 - Assignees: Linde Aktiengesellschaft - Inventors: Franz Forster - Web page: https://patentgrep.com/patent/US5699715A ## CPC - F04B 1/148: Bearings therefor - F04B 1/16: having two or more sets of cylinders or pistons - Y10T 74/18336: Wabbler type - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A piston for use in a reciprocating piston machine having a wobble plate has a first segment and a second segment axially spaced from and aligned with the first segment. A bridge segment connects the first and second piston segments for simultaneous reciprocal movement and at least one body is attached to the bridge segment to connect the piston to a wobble plate. ## Claims ### Claim 1 A piston for use in a reciprocating piston machine having a wobble plate, said piston having a first piston segment and a second piston segment axially spaced from and aligned with said first piston segment, a bridge segment connecting said first and second piston segments for simultaneous reciprocal movement, and a means for operatively connecting said piston to a wobble plate, whereby a relative velocity perpendicular to the center axis of said piston and tangential to a wobble plate occurs between said piston and said wobble plate during reciprocal movement of said piston, wherein said means for operatively connecting said piston to said wobble plate includes a cavity in said bridge segment and two support bodies mounted within said cavity in said bridge segment which are adapted to lie on opposed sides of said wobble plate wherein each of said two support bodies mounted in said bridge segment is a segment of a sphere and said segments have coaxial mean perpendiculars wherein said piston has opposed ends for one of the displacement of a pressure medium and the pressurization of a pressure medium. ### Claim 2 (depends on 1) A piston as set forth in claim 1, wherein said first piston segment and said second piston segment are coaxial. ### Claim 3 (depends on 1) A piston as set forth in claim 1, wherein said spherical segments form a sphere having a center located on the center axis of said first and second piston segments. ### Claim 4 (depends on 1) A piston as set forth in claim 1, wherein said spherical segments form a sphere having a center adapted to be located on the center plane of a wobble plate located between said support bodies. ### Claim 5 (depends on 3) A piston as set forth in claim 3, wherein said spherical segments form a sphere having a center adapted to be located on the center plane of a wobble plate located between said support bodies. ### Claim 6 (depends on 2) A piston as set forth in claim 2, wherein said spherical segments form a sphere having a center adapted to be located on the center plane of a wobble plate located between said support bodies. ### Claim 7 (depends on 1) A piston as set forth in claim 1, wherein said support bodies are segments of a common surrounding sphere. ### Claim 8 (depends on 2) A piston as set forth in claim 2, wherein said support bodies are segments of a common surrounding sphere. ### Claim 9 (depends on 8) A piston as set forth in claim 8, wherein said spherical segments are segments of a common surrounding sphere. ### Claim 10 (depends on 1) A piston as set forth in claim 1, wherein said first piston segment and said second piston segment have the same diameter. ### Claim 11 (depends on 1) A piston as set forth in claim 1, including hydrostatic bearings on a surface of each of said support bodies within said bridge segment and on the surface of each of said support bodies adapted to face said wobble plate. ### Claim 12 (depends on 1) A piston as set forth in claim 1, including means on said bridge segment for preventing rotation of said piston around the center axis of said piston. ### Claim 13 (depends on 1) A piston as set forth in claim 1, wherein said bridge segment has an outwardly opening elongated axial groove formed thereon adapted to contact a guide profile on a housing for said piston to prevent rotation of said piston around the axis of said piston. ### Claim 14 A piston for use in a reciprocating piston machine having a wobble plate, said piston having a first piston segment and a second piston segment axially spaced from and aligned with said first piston segment, a bridge segment connecting said first and second piston segments for simultaneously reciprocal movement, and means for operatively connecting said piston to said wobble plate, said means including a cavity in said bridge segment and two support bodies mounted within said cavity in said bridge segment and adapted to lie on opposite sides of said wobble plate, pressure pockets formed in said bridge segment adjacent each said support body creating hydrostatic bearings on a surface of each said support body within said bridge segment, and a pressure pocket formed on a surface of each said support body facing said wobble plate whereby a hydrostatic bearing is formed between said support bodies and said wobble plate, whereby a relative velocity perpendicular to the center axis of said piston and tangential to a wobble plate occurs between said piston and said wobble plate during reciprocal movement of said piston. ### Claim 15 (depends on 14) A piston as set forth in claim 14, wherein said support bodies are segments of a common surrounding sphere. ### Claim 16 (depends on 14) A piston as set forth in claim 14, wherein said piston has opposed ends for one of the displacement of a pressure medium and the pressurization of pressure medium. ### Claim 17 (depends on 14) A piston as set forth in claim 14, wherein said bridge segment has an outwardly opening elongated axial groove formed thereon adapted to contact a guide profile on a housing for said piston to prevent rotation of said piston around the axis of said piston. ### Claim 18 (depends on 14) A piston as set forth in claim 14 wherein each said piston segment includes an axial passageway extending to one said pressure pocket formed in said bridge segment. ### Claim 19 (depends on 18) A piston as set forth in claim 18, wherein said bridge segment has an outwardly opening elongated axial groove formed thereon adapted to contact a guide profile on a housing for said piston to prevent rotation of said piston around the axis of said piston. ### Claim 20 (depends on 19) A piston as set forth in claim 19 further including radial passageways extending through each said support body to said pressure pocket formed in said support body.