# US 8,770,842 B2 · Sliding member and manufacturing method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,770,842 B2 - Document ID: US8770842B2 - Status: Granted - Kind: B2 - Application number: 13/704,092 - Filed: 2011-03-22 - Published: 2013-04-11 - Granted: 2014-07-08 - Earliest claimed: 2010-07-27 - Assignees: Taiho Kogyo Co., Ltd. - Applicants: Satoshi Nomura; Masaharu Hatta; Hiroshi Kanemitsu - Inventors: Satoshi Nomura; Masaharu Hatta; Hiroshi Kanemitsu - Web page: https://patentgrep.com/patent/US8770842B2 ## CPC - F16C 17/12: characterised by features not related to the direction of the load - C21D 1/09: by direct application of electrical or wave energy; by particle radiation - C21D 1/38: Heating by cathodic discharges - C21D 9/00: Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor - C21D 9/0068: {for particular articles not mentioned below} - F04B 27/0886: {Piston shoes} - F16C 33/1065: {Grooves on a bearing surface for distributing or collecting the liquid} - F16C 33/14: Special methods of manufacture; Running-in - C21D 2221/00: Treating localised areas of an article - F05C 2251/10: Hardness - F05C 2253/24: Heat treatment - F16C 2223/06: polishing - F16C 2223/10: Hardening, e.g. carburizing, carbo-nitriding - F16C 2360/00: Engines or pumps - F16C 2362/52: Compressors of refrigerators, e.g. air-conditioners - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS - C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B) - 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) - F05C: INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES ## Abstract A hemispherical shoe (sliding member) 1 has a flat sliding surface 3, which is quenched to form a quenched portion 7. A part of the quenched sliding surface is partially annealed to form an annealed portion 6. When an oil film pressure acts on the sliding surface 1, the annealed portion 6 is deformed by pressure so that the surface thereof has a concave portion 6A. In the annealed portion 6, a remaining quenched portion 8 may remain at the center part thereof. The concave portion 6A can be used as an oil reservoir or an oil flow path, so that an excellent seizure resistance can be ensured. ## Claims ### Claim 1 A sliding member having a sliding surface slidable relative to a counterpart material, wherein at least the sliding surface of the sliding member is quenched so that a quenched portion is formed, a part of the quenched portion is partially annealed so that an annealed portion is formed, and the annealed portion is deformed by pressure to have a concave surface therein when an oil film pressure acts on the sliding surface. ### Claim 2 (depends on 1) The sliding member according to claim 1, wherein the surface of the quenched portion and the surface of the annealed portion are formed to be flat and the sliding surface having the quenched portion and annealed portion formed thereon are formed to be flat. ### Claim 3 (depends on 1) The sliding member according to claim 1, wherein the surface of the quenched portion is formed to be flat and the surface of the annealed portion is formed in a concave shape. ### Claim 4 (depends on 1) The sliding member according to claim 1, wherein a quenched portion remains at a center part of the annealed portion. ### Claim 5 (depends on 4) The sliding member according to claim 4, wherein the surface of the quenched portion remaining at the center part of the annealed portion is formed to be flat. ### Claim 6 (depends on 4) The sliding member according to claim 4, wherein the surface of the quenched portion remaining at the center part of the annealed portion is formed in a concave shape. ### Claim 7 (depends on 4) The sliding member according to claim 4, wherein the surface of the quenched portion remaining at the center part of the annealed portion is formed in a convex shape. ### Claim 8 (depends on 1) The sliding member according to claim 1, wherein the annealed portion is the form of at least one of parallel linear form, concentric form, helical form, spiral form, lattice form, scattered circular form and a dot form. ### Claim 9 (depends on 1) The sliding member according to claim 1, wherein the sliding member is a hemispherical shoe, the shoe has a hemispherical sliding surface and a flat sliding surface, and the quenched portion and the annealed portion are formed on the flat sliding surface. ### Claim 10 A method for manufacturing a sliding member having a sliding surface that slides relative to a counterpart material, comprising the steps of: quenching all of the sliding surface of the sliding member to form a quenched sliding surface; annealing a portion of the quenched sliding surface to form an annealed portion of the sliding surface; and flattening the sliding surface after the annealing step. ### Claim 11 (depends on 10) The method of claim 10, wherein a remaining quenched portion of the sliding surface is provided at a center part of the annealed portion of the sliding surface. ### Claim 12 (depends on 11) The method of claim 11, additionally comprising the step of subjecting the quenched portion of the sliding surface to tempering to form a concavity therein. ### Claim 13 (depends on 10) The method of claim 10, additionally comprising the step of forming a concavity in the surface of the annealed portion of the flattened sliding surface. ### Claim 14 (depends on 10) The method of claim 10, wherein the annealed portion of the sliding surface is in the form of at least one of parallel linear form, concentric form, helical form, spiral form, lattice form, scattered circular form and dot form.