Patent US4944663A successfully refreshed from Google Patents.
US4944663A
Expired / Lapsed
US
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Rotary compressor having oxidizing and nitriding surface treatment
Assignee: Hitachi Ltd
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Filing: 1989-04-19
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Granted: 1990-07-31
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Expires: 2009-04-19
Abstract
Abstract A sliding member of an iron-based non-porous material, such as vane, of a rotary compressor has a sliding surface processed by a surface treatment in which the surface is subjected to oxidizing and nitriding to form an oxidized and nitrided layer thereon. The surface is then subjected to a steam-treatment in which water is caused to react with components of the oxidized and nitrided layer to form a layer of oxidized iron of a porous network structure disposed outwardly of the oxidized and nitrided layer. The oxidized iron layer is composed mainly of tri-iron tetroxide and softer than the oxidized and nitrided layer.
Inventors
- 👤 Tadashi Iizuka
- 👤 Kazushi Fukuda
- 👤 Shin Ishihara
- 👤 Yasuo Kamitsuma
- 👤 Yusaku Nakagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:49
CPC Classifications
F; F01; F01C; F01C21/00; F01C21/08; F01C21/0809; F04; F04C; F04C2230/00; F04C2230/90; F04C2230/92; F05; F05B; F05B2230/00; F05B2230/90; F05B2280/00; F05B2280/20; F05C; F05C2201/00; F05C2201/04; F05C2201/0433; F05C2201/0436; F05C2201/0439; F05C2201/0442; F05C2201/0448; F05C2201/0457; F05C2253/00; F05C2253/12
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
99 words
A compressor including a cylinder, a roller disposed therein in an eccentric relationship thereto, a crankshaft for rotating said roller in said cylinder and a vane disposed in sliding engagement with said roller, at least one of said cylinder, said roller, said crankshaft and said vane comprising a member which is made from a ferrous substantially non-porous material and which has a surface disposed in relative sliding engagement with an associated member, said surface comprising a first porous layer of oxidized iron backed up by a second layer of oxidized and nitrided iron disposed inwardly of said first layer.
Claim 2
Dependent Claim
99 words
A compressor including a cylinder, a roller disposed therein in an eccentric relationship thereto, a crankshaft for rotating said roller in said cylinder and a vane disposed in sliding engagement with said roller, at least one of said cylinder, said roller, said crankshaft and said vane comprising a member which is made from a ferrous substantially non-porous material and which has a surface disposed in relative sliding engagement with an associated member, said surface comprising a first porous layer of oxidized iron backed up by a second layer of oxidized and nitrided iron disposed inwardly of said first layer.
Claim 3
Dependent Claim
54 words
A compressor according to claim 1, wherein said crankshaft has a pin portion on which said roller is rotatably mounted and wherein said cylinder is formed therein with a vane slot in which said vane is slidably received and has an end disposed in sliding engagement with an outer peripheral surface of said roller.
Claim 4
Dependent Claim
17 words
A compressor according to claim 1, wherein said first porous layer is composed mainly of tri-iron tetroxide.
Claim 5
Dependent Claim
17 words
A compressor according to claim 2, wherein said first porous layer is composed mainly of tri-iron tetroxide.
Claim 6
Dependent Claim
25 words
A compressor according to claim 2, wherein said one member is the vane and wherein said vane is made of a high speed tool steel.
Claim 7
Dependent Claim
15 words
A compressor according to claim 5, wherein said cylinder is made of a cast iron.
Claim 8
Dependent Claim
15 words
A compressor according to claim 5, wherein said roller is made of a cast iron.
Claim 9
Dependent Claim
23 words
A compressor according to claim 1, wherein said one member is the crankshaft and wherein said crankshaft is made of a cast iron.
Claim 10
Dependent Claim
23 words
A compressor according to claim 2, wherein said one member is the crankshaft and wherein said crankshaft is made of a cast iron.
Claim 11
Dependent Claim
16 words
A compressor according to claim 9, wherein said roller is made of a quality-adjusted cast iron.
Claim 12
Dependent Claim
33 words
A compressor according to claim 1, further including upper and lower bearings each having a first portion rotatably supporting said crankshaft and a second portion disposed in relatively sliding engagement with said roller.
Claim 13
Dependent Claim
23 words
A compressor according to claim 11, wherein said one member is the roller and said upper bearing is formed of a cast iron.
Claim 14
Dependent Claim
25 words
A compressor according to claim 11, wherein said one member is the roller and wherein said lower bearing is formed of a sintered ferrous material.
Claim 15
Dependent Claim
67 words
A machine including at least one pair of relatively slidable members at least one of which is made from a ferrous substantially non-porous material and has a surface disposed in relatively sliding engagement with an associated member, said surface comprising a first layer of oxidized iron backed up by a second layer of oxidized and nitrided iron formed in said one member inwardly of said first layer.
Claim 16
Dependent Claim
67 words
A machine including at least one pair of relatively slidable members at least one of which is made from a ferrous substantially non-porous material and has a surface disposed in relatively sliding engagement with an associated member, said surface comprising a first layer of oxidized iron backed up by a second layer of oxidized and nitrided iron formed in said one member inwardly of said first layer.
Claim 17
Dependent Claim
22 words
A machine according to claim 14, wherein said first layer has a porous network structure and is composed mainly of tri-iron tetroxide.
References Cited (Backward Citations)
US3748195A
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JPS51122812A
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JPS6073082A
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JPS6213784A
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JPS6232293A
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JPS63191286U
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JPH01134093A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |