Source: http://www.google.com/patents/US5407334?ie=ISO-8859-1
Timestamp: 2014-07-10 13:04:52
Document Index: 378275307

Matched Legal Cases: ['art 2', 'art 2', 'art 2', 'art 3', 'art 2', 'art 3', 'art 6', 'art 6', 'art 6', 'art 6']

Patent US5407334 - Scroll type compressor having a convex surface on the sub frame bushing - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsA scroll type compressor having a main frame, a sub frame and a crankshaft rotatably mounted in the main frame and the sub frame via a main frame bushing and a sub frame bushing, further includes a fixed scroll and an orbiting scroll cooperable with the fixed scroll to compress gas, the orbiting scroll...http://www.google.com/patents/US5407334?utm_source=gb-gplus-sharePatent US5407334 - Scroll type compressor having a convex surface on the sub frame bushingAdvanced Patent SearchPublication numberUS5407334 APublication typeGrantApplication numberUS 08/175,125Publication dateApr 18, 1995Filing dateDec 29, 1993Priority dateMar 4, 1991Fee statusPaidAlso published asUS5222881, US5312229, USRE36604Publication number08175125, 175125, US 5407334 A, US 5407334A, US-A-5407334, US5407334 A, US5407334AInventorsFumiaki Sano, Masahiko Oide, Toshiyuki Nakamura, Hiroshi Ogawa, Norihide Kobayashi, Yoshinori Shirafuji, Takashi Yamamoto, Keiji SakainoOriginal AssigneeMitsubishi Denki Kabushiki KaishaExport CitationBiBTeX, EndNote, RefManPatent Citations (5), Referenced by (9), Classifications (23), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetScroll type compressor having a convex surface on the sub frame bushingUS 5407334 AAbstract A scroll type compressor having a main frame, a sub frame and a crankshaft rotatably mounted in the main frame and the sub frame via a main frame bushing and a sub frame bushing, further includes a fixed scroll and an orbiting scroll cooperable with the fixed scroll to compress gas, the orbiting scroll being drivingly mounted on the eccentric shaft portion. A barrel shaped band portion faces the crankshaft and presents a convex surface in at least one of a respective force direction of a compressive load generated in a compression chamber formed between the orbiting scroll and the fixed scroll, and a reactive force direction of a centrifugal load generated by a revolution movement of the orbiting scroll and rotary movements of upper and lower balance weights. The barrel shaped band portion is formed on the sub frame bushing.
We claim: 1. A scroll type compressor comprising:a main frame; sub frame; a main frame bushing and a sub frame bushing rotatably mounted in said main frame and said sub frame; a crankshaft rotatably mounted in said main frame and said sub frame via said main frame bushing and said sub frame bushing, said crankshaft having an eccentric shaft portion formed thereon, wherein the main frame and sub frame are mutually spaced along the axis of the crankshaft; a fixed scroll; an orbiting scroll cooperable with the fixed scroll to compress gas, said orbiting scroll being drivingly mounted on said eccentric shaft portion; an electric motor mounted between said main frame and said sub frame and having a rotor coupled to said crankshaft for driving said crankshaft; upper and lower balance weights placed at opposite ends of said rotor for balancing orbiting movement of said orbiting scroll; a pin connected between said sub frame bushing and the crankshaft for rotatably coupling the sub frame bushing to the crankshaft; and a barrel shaped band portion presenting a convex surface in at least one of a respective force direction of a compressive load generated in a compression chamber formed between the orbiting scroll and the fixed scroll, and a reactive force direction of a centrifugal load generated by a revolution movement of the orbiting scroll and rotary movements of the upper and lower balance weights, the barrel shaped band portion facing the crankshaft and being formed on said sub frame bushing. Description
This is a division of application Ser. No. 08/043,806, filed on Apr. 7, 1993, U.S. Pat. No. 5,312,229 which is a division of appl. Ser. No. 07/834,220, filed on Feb. 12, 1992, U.S. Pat. No. 5,222,881.
BACKGROUND OF THE INVENTION The present invention relates to a scroll type compressor, and more particularly to a scroll type compressor which is utilized in refrigeration and air conditioning systems.
A conventional scroll type compressor, which has been disclosed in e.g. Japanese Unexamined Patent Publication No. 80088/1988, is constructed as shown in FIG. 17. In FIG. 17, reference numeral 1 designates a fixed scroll. Reference numeral 2 designates an orbiting scroll. Reference numeral 3 designates a crankshaft. Reference numeral 4 designates a driving bushing which is rotatably mounted in a bearing part 2a formed in the orbiting scroll 2. Reference numeral 5 designates an Oldham's ring. Reference numeral 6 designates a main frame. Reference numeral 6a designates a main bearing which is formed in the main frame 6. Reference numeral 7 designates an electric motor stator. Reference numeral 8 designates an electric motor rotor. Reference numeral 9 designates a sub frame. Reference numeral 9a designates a sub bearing which is formed in the sub frame 9. Reference numeral 10 a hermetic shell. Reference numeral 11 designates an intake tube which directs a refrigerant from outside. Reference numeral 12 designates a discharge tube. Reference numeral 13 designates a lubricating oil which is stored in a bottom part of the hermetic shell. The crankshaft 3 has an eccentric shaft portion 3a formed at an upper portion. The eccentric shaft portion 3a is fitted into the bearing part 2a through the driving bushing 4, the bearing part 2a being formed on a base plate undersurface of the orbiting scroll 2. The crankshaft 3 has a main shaft portion 3b and a sub frame shaft portion 3c formed on its upper end and lower end, respectively, so that the main shaft portion 3b is supported by the main bearing 6a of the main frame 6 and the sub shaft part 3c is supported by the sub bearing 9a of the sub frame 9. Reference numerals 14 and 15 designate an upper balance weight and a lower balance weight, respectively, which are attached on the opposite sides (in the vertical direction) of the electric motor rotor 8.
In the conventional scroll type compressor, the radial direction force Fg which is applied to the orbiting scroll in the compression stroke is exerted on the eccentric shaft portion 3a which is at the upper end of the crankshaft 3, as explained. However, because the eccentric shaft portion 3a as the exerting point projects from the main bearing 6a of the main frame 6 in the direction remote from the bearing 9a, the compressive load Fg causes the crankshaft 3 to be flexture-deformed as shown in FIG. 19. When the crankshaft 3 is flexure-deformed, the eccentric shaft portion 3a is inclined in the bearing part 2a of the orbiting scroll 2, the main shaft portion 3b is inclined in the main bearing 6a of the main frame 6, or the sub shaft part 3c is inclined in the sub bearing 9a of the sub frame 9. This creates e.g. a problem in that load carrying capacities of the respective bearing parts can deteriorate to wear or seize the bearing parts.
SUMMARY OF THE INVENTION It is an object of the present invention to solve the problem, and to provide a highly reliable scroll type compressor capable of preventing a bearing part from being damaged due to wear, seize or the like even if a crankshaft is flexture-deformed by a radial direction force in compressive loads which are exerted to an orbiting scroll during a compression stroke.
It is further advisable that the scroll type compressor further comprises an upper balance weight and a lower balance weight placed on the opposite ends of the rotor to be balanced against a centrifugal force which is generated by an orbiting movement of the orbiting scroll; and the bearing means comprising bearing devices which are provided in a main frame and a sub frame to support the crankshaft at its main shaft portion and sub shaft portion; wherein in order to prevent partial contact from bringing about due to flexture-deformation of the crankshaft in the bearing parts for supporting the main shaft and sub shaft portions of the crankshaft, at least one of the main shaft portion and the sub shaft portion has a central portion provided with a barrel shaped band portion to present a convex surface in the entire peripheral direction, the band portion has a peripheral portion engaged with the bushing through a minute gap.
It is still further advisable that the scroll type compressor comprises an upper balance weight and a lower balance weight placed on the opposite ends of the rotor to be balanced against a centrifugal force which is generated by an orbiting movement of the orbiting scroll; and the bearing means comprising bearing devices which are provided in a main frame and a sub frame to support the crankshaft at its main shaft portion and sub shaft portion; wherein in order to prevent partial contact from bringing about due to flexture-deformation of the crankshaft in the bearing devices, the main shaft portion has a central portion provided with a barrel shaped band portion to present a convex surface in the entire peripheral direction, the band portion has a peripheral portion engaged with the bushing through a minute gap, and the bushing is coupled to the crankshaft by a pin in terms of a rotational direction; and wherein the bearing device for supporting the sub shaft portion of the crankshaft is constructed by a rolling bearing to prevent partial contact from bringing about in the bearing device due to flexture-deformation of the crankshaft.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing a first embodiment of a scroll type compressor according to the present invention;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The scroll type compressor according to the present invention will be described in detail, referring to embodiments shown in the accompanying drawings. In FIG. 1, there is shown the scroll type compressor 20 according to a first embodiment of the present invention. In FIG. 1 showing the scroll type compressor 20 of the first embodiment, similar or corresponding parts are indicated by the same reference numerals as the conventional scroll type compressor shown in FIG. 17, and explanation of those parts will be omitted for the sake of simplicity.
In accordance with the bearing structure which is constituted by the main shaft portion 23 of the crankshaft 21 having the central portion provided with the barrel shaped band portion to present the convex surface in the entire peripheral direction, and the cylndrical bushing 33 arranged in the main bearing part 6a of the main frame 6, the contacting points between the curved surface on the band portion 32 of the main shaft portion 23 and the cylindrical bushing 33 can move following a flexing direction and a flexing magnitude of the crankshaft 21 though the compressive load Fg and centrifugal loads FC1, FC2 and FC3 which are applied on the crankshaft 21 are substantially rectangular in their directions, and their magnitudes vary depending on the operating conditions of the compressor to change the flexing direction of the crankshaft 21. Irrespectively of the operating conditions of the compressor, the cylindrical bushing 33 can rotate while constantly maintaining a parallel state to the main bearing part 6a of the main frame 6 (maintaining such a state that the central rotating axis of the cylindrical bushing 33 corresponds to the central axis of the main bearing part 6a).
As shown in FIG. 11, the main shaft portion 23 of the crankshaft 21 may be formed in such a manner that two surfaces which are located in a reactive force direction of the compressive load direction Fg and in a reactive force direction of centrifugal loads FC1, FC2 and FC3 (FC3 is not shown in FIG. 11 but is understood to be the same as shown in FIG. 18) have curved surfaces 23a and 23b formed on central portions thereof to present convex surfaces, that a cylindrical bushing 35 which has flat surfaces 35a and 35b formed on the inner peripheral surface thereof at locations corresponding to the curved surfaces 23a and 23b, and that the main shaft portion 23 has the cylindrical bushing 35 engaged therewith. Such an arrangement allows the cylindrical bushing 35 to follow flexure-deformation of the crankshaft 21 due to the compressive load Fg, and the centrifugal loads FC1, FC2 and FC3, and to move its contacting points on the curved surfaces 23 a and 23b of the main shaft portion 23 of the crankshaft 21. As a result, the cylindrical bushing can be rotated, maintaining a parallel state to the main bearing part 6a of the main frame 6, and can offer an advantage similar to the bearing structure stated above. In this case, the two curved surfaces 23a and 23b can also work to connect the crankshaft 21 and the cylindrical bushing 35 in a circumferential direction to need no connecting pin.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4808094 *Jan 24, 1986Feb 28, 1989Sanden CorporationDrive system for the orbiting scroll of a scroll type fluid compressorUS5137437 *Jan 8, 1991Aug 11, 1992Hitachi, Ltd.Scroll compressor with improved bearingUS5186546 *Jul 9, 1991Feb 16, 1993Hitachi, Ltd.Self-aligning bearing and closed-type electrically driven compressor having the sameAT107213B * Title not availableJPH01170779A * Title not available* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS6162125 *Apr 19, 1999Dec 19, 2000Ford Global TechnologiesMotor shaft to gear pump coupling device for fluid borne noise reductionUS7878776Dec 28, 2006Feb 1, 2011Emerson Climate Technologies, Inc.Thermally compensated scroll machineUS8007261Dec 28, 2006Aug 30, 2011Emerson Climate Technologies, Inc.Thermally compensated scroll machineUS8308366Jun 18, 2009Nov 13, 2012Eaton Industrial CorporationSelf-aligning journal bearingUS8308367 *Apr 16, 2008Nov 13, 2012Abi Anlagentechnik-Baumaschinen-Industriebedarf Maschinenfabrik Und Vertriebsgesellschaft MbhCompensation of rotational shaft inclinationUS8641393Dec 21, 2010Feb 4, 2014Emerson Climate Technologies, Inc.Thermally compensated scroll machineUS20100098370 *Jan 22, 2008Apr 22, 2010Kock Peter DeRoller bearingUS20100202717 *Apr 16, 2008Aug 12, 2010Albrecht KleiblCompensation of Rotational Shaft InclinationWO2010146450A1 *Jun 17, 2010Dec 23, 2010Eaton CorporationSelf-aligning journal bearing* Cited by examinerClassifications U.S. Classification418/55.1, 418/57, 418/55.5, 384/192, 418/182, 403/121, 464/106International ClassificationF01C21/02, F04C29/00, F04C23/00, F04C18/02, F16D3/20Cooperative ClassificationF04C23/008, F04C18/0215, F01C21/02, F16D3/20, F04C2240/807, F04C2240/601, F04C29/0057European ClassificationF04C29/00D2B, F04C18/02B2, F01C21/02, F16D3/20Legal EventsDateCodeEventDescriptionSep 22, 2006FPAYFee paymentYear of fee payment: 12Sep 19, 2002FPAYFee paymentYear of fee payment: 8Oct 15, 1998FPAYFee paymentYear of fee payment: 4Oct 20, 1994ASAssignmentOwner name: MITSUBISHI DENKI KABUSHIKI KAISHA, JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SAKAINO, KEIJU;REEL/FRAME:007170/0865Effective date: 19940930RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google