JP2009270568A - Bearing housing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing housing having a bearing structure capable of inhibiting uneven contact of a main shaft section of a crankshaft more than a conventional bearing structure. <P>SOLUTION: The bearing housing 23 includes a main body section 23a, a cylindrical bearing section 32 and a support section 23b. The main body section assumes a cylindrical shape. The cylindrical bearing section lies inside the main body section as viewed in a plane. The support section extends from a central part CP1 of the cylindrical bearing section to the main body section and supports the cylindrical bearing section on the main body section. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bearing housing.

  In the past, in a scroll compressor, an annular groove was provided in the upper end portion of the bearing portion of the bearing housing in order to suppress the contact of the main shaft portion with respect to the bearing when the main shaft portion of the crankshaft was bent and deformed. There has been a proposal that “a part functions as an elastic bearing” (see Japanese Patent Application Laid-Open No. 2003-206873).

  The subject of this invention is providing the bearing housing which has a bearing structure which can suppress the contact | abutting of the main-shaft part of a crankshaft rather than the conventional bearing structure.

  A bearing housing according to a first aspect of the present invention includes a main body portion, a cylindrical bearing portion, and a support portion. The main body has a cylindrical shape. When the bearing housing according to the present invention is used for a scroll compressor, the main body usually has a recess for accommodating the rotation preventing member of the movable scroll, a base portion of the movable scroll provided adjacent to the recess, and the like. Is provided. When the bearing housing according to the present invention is used for a rotary compressor or a swinging rotary compressor, the bearing housing is used as a front head and a rear head. The cylindrical bearing portion is located inside the main body portion in plan view. The support portion extends from the central portion of the cylindrical bearing portion to the main body portion, and supports the cylindrical bearing portion on the main body portion. In addition, when the bearing housing according to the present invention is used in a scroll compressor, the shape of the support portion is not particularly limited (for example, a disk shape or a radial shape), but the thickness is thin enough to cause no problem in strength, A shape that can flexibly cope with deformation is preferred. Further, when the bearing housing according to the present invention is used in a rotary compressor or a oscillating rotary compressor, the shape of the support portion is a disc shape in a plan view and is thick enough to cause no problem in strength. It is preferable that it has a shape that can flexibly cope with deformation, such as being thin. The ratio of the total length of the cylindrical bearing portion to the thickness of the cylindrical bearing portion is preferably larger than 10.

  In this bearing housing, the support portion extends from the central portion of the cylindrical bearing portion to the main body portion, and supports the cylindrical bearing portion on the main body portion. For this reason, if the thickness of the cylindrical bearing portion is sufficiently thin, both ends in the axial direction of the cylindrical bearing portion can be freely bent, and as a result, the behavior of the crankshaft in the radial direction and the shaft misalignment of the upper and lower bearings It is possible to follow the tilt due to. Therefore, if this bearing housing is employed in a scroll compressor, a rotary compressor, or a swinging rotary compressor, it is possible to suppress the contact of the main shaft portion of the crankshaft as compared with the related art.

  A bearing housing according to a second invention is the bearing housing according to the first invention, and the cylindrical bearing portion is semi-molten die-cast from cast iron having a carbon content of 2.0 wt% to 2.7 wt%. Or a semi-solid die casting method.

  Cylindrical bearing parts formed from cast iron having a carbon content of 2.0 wt% to 2.7 wt% by a semi-molten die casting method or a semi-solid die casting method are sand-cast from ordinary cast iron such as FC250. Compared to a cylindrical bearing portion formed by the method, the tensile elastic modulus is about 1.6 times, and the tensile strength is about 3 times. Incidentally, the former tensile elastic modulus is about 180 GPa, while the latter tensile elastic modulus is about 110 GPa. The former has a strength of about 750 MPa, while the latter has a tensile strength of about 250 MPa. Therefore, if the safety factor against destruction of the former cylindrical bearing part is the same as the safety factor against destruction of the latter cylindrical bearing part, the thickness of the former cylindrical bearing part is greater than the thickness of the latter cylindrical bearing part. It can be thin. Thus, the cylindrical bearing portion of the bearing housing according to the present invention has an increased tolerance for “deflection” compared to the conventional cylindrical bearing portion. As a result, the cylindrical bearing portion of the bearing housing according to the present invention can follow the deflection of the crankshaft more than the conventional cylindrical bearing portion, and consequently the main shaft portion of the crankshaft is more than the conventional cylindrical bearing portion. It is possible to suppress the piece contact.

  A bearing housing according to a third aspect is the bearing housing according to the second aspect, wherein the main body and the support are made of flake graphite cast iron or spheroidal graphite cast iron.

  Generally, flake graphite cast iron and spheroidal graphite cast iron are obtained rather than obtaining a molded body from a cast iron having a carbon content of 2.0 wt% to 2.7 wt% by a semi-molten die cast molding method or a semi-solid die casting method. Thus, it is possible to obtain a molded body at a lower cost by obtaining the molded body by a casting method. Therefore, if such a bearing housing is molded, the manufacturing cost can be kept low. In order to mold such a bearing housing, a cylindrical shape is formed from a cast iron having a carbon content of 2.0 wt% to 2.7 wt% in advance by a semi-molten die casting method or a semi-solid die casting method. It is necessary to mold the bearing part and prepare the cylindrical bearing part in the mold of the bearing housing before molding the bearing housing.

  A bearing housing according to a fourth aspect is the bearing housing according to the first aspect, wherein the cylindrical bearing portion is made of spheroidal graphite cast iron.

  For this reason, in this bearing housing, the wear resistance of the cylindrical bearing portion can be kept good.

  A bearing housing according to a fifth aspect of the present invention is the bearing housing according to the fourth aspect of the present invention, wherein the main body part and the support part are made of flake graphite cast iron.

  In general, the production cost of a flake graphite cast iron compact is lower than that of a spheroidal graphite cast iron compact. Therefore, if such a bearing housing is molded, the manufacturing cost can be kept low. In order to mold such a bearing housing, a cylindrical bearing portion made of spheroidal graphite cast iron is molded in advance, and the cylindrical bearing portion is charged into a mold of the bearing housing before molding the bearing housing. There is a need.

  A scroll compressor according to a sixth aspect of the present invention includes a first scroll, a second scroll, a bearing housing, a crankshaft, and a rotation drive mechanism. The second scroll has a bearing portion. Further, the second scroll makes a turning motion relative to the first scroll while being engaged with the first scroll. The bearing housing is a bearing housing according to any one of the first to fifth inventions. The crankshaft has an eccentric shaft portion and a main shaft portion. The eccentric shaft portion is fitted into the bearing portion of the second scroll. The main shaft portion is inserted through the cylindrical bearing portion of the bearing housing. The rotational drive mechanism rotationally drives the crankshaft. This scroll compressor can suppress the contact of the main shaft portion of the crankshaft with respect to the conventional one.

  A scroll compressor according to a seventh invention is the scroll compressor according to the sixth invention, and compresses carbon dioxide. This scroll compressor can suppress the contact of the main shaft portion of the crankshaft with respect to the conventional one.

 A rotary compressor according to an eighth invention includes a cylinder block, a first bearing housing, a second bearing housing, a roller, a vane, a crankshaft, and a rotation drive mechanism. The cylinder block has a cylindrical hole that passes through the center along the thickness direction. The first bearing housing includes the bearing housing according to any one of the first to fifth inventions, and is provided at a position adjacent to the cylinder block along the plate thickness direction. The second bearing housing includes the bearing housing according to any one of the first to fifth inventions, and is provided at a position adjacent to the cylinder block along the plate thickness direction, and the cylinder block is connected to the first bearing housing. It is provided at the position to be fitted. The roller is disposed in a compression space surrounded by the cylinder block, the first bearing housing, and the second bearing housing. The vane slidably contacts the roller and divides the compression space into two spaces. The crankshaft has an eccentric shaft portion and a main shaft portion. A roller is rotatably inserted into the eccentric shaft portion. The main shaft portion is inserted through the cylindrical bearing portion of the first bearing housing. The rotation drive mechanism rotates the crankshaft. This rotary compressor can suppress the contact of the main shaft portion of the crankshaft as compared with the conventional one.

 A rotary compressor according to a ninth invention is the rotary compressor according to the eighth invention, and compresses carbon dioxide. This rotary compressor can suppress the contact of the main shaft portion of the crankshaft as compared with the conventional one.

 A rocking rotary compressor according to a tenth aspect of the present invention includes a cylinder block, a first bearing housing, a second bearing housing, a piston, a crankshaft, and a rotation drive mechanism. The cylinder block has a cylindrical hole that passes through the center along the thickness direction. The first bearing housing includes the bearing housing according to any one of the first to fifth inventions, and is provided at a position adjacent to the cylinder block along the plate thickness direction. The second bearing housing includes the bearing housing according to any one of the first to fifth inventions, and is provided at a position adjacent to the cylinder block along the plate thickness direction, and the cylinder block is connected to the first bearing housing. It is provided at the position to be fitted. The piston has a roller portion and a blade portion. The roller portion is disposed in a compression space surrounded by the cylinder block, the first bearing housing, and the second bearing housing. The blade part is formed integrally with the roller part. The blade portion divides the compression space into two spaces. The crankshaft has an eccentric shaft portion and a main shaft portion. The eccentric shaft portion has a roller portion rotatably inserted therein. The main shaft portion is inserted through the cylindrical bearing portion of the first bearing housing. The rotation drive mechanism rotates the crankshaft. This oscillating rotary compressor can suppress the contact of the main shaft portion of the crankshaft as compared with the conventional one.

 An oscillating rotary compressor according to an eleventh aspect of the invention is the oscillating rotary compressor according to the tenth aspect of the invention, and compresses carbon dioxide. This oscillating rotary compressor can suppress the contact of the main shaft portion of the crankshaft as compared with the conventional one.

  In the bearing housing according to the first invention, the support portion extends from the central portion of the cylindrical bearing portion to the main body portion, and supports the cylindrical bearing portion on the main body portion. For this reason, if the thickness of the cylindrical bearing portion is sufficiently thin, both ends in the axial direction of the cylindrical bearing portion can be freely bent, and as a result, the behavior of the crankshaft in the radial direction and the shaft misalignment of the upper and lower bearings It is possible to follow the tilt due to. Therefore, if this bearing housing is employed in a scroll compressor, a rotary compressor, or a swinging rotary compressor, it is possible to suppress the contact of the main shaft portion of the crankshaft as compared with the related art.

  In the bearing housing according to the second aspect of the present invention, the cylindrical bearing portion has an increased allowable amount of “deflection” compared to the conventional cylindrical bearing portion. As a result, in the bearing housing according to the present invention, the cylindrical bearing portion can follow the deflection of the crankshaft more than the conventional cylindrical bearing portion, and consequently the main shaft portion of the crankshaft than the conventional cylindrical bearing portion. Can be suppressed.

  The bearing housing according to the third aspect of the invention can reduce the manufacturing cost.

  In the bearing housing according to the fourth invention, the wear resistance of the cylindrical bearing portion can be kept good.

  The bearing housing according to the fifth aspect of the present invention can keep the manufacturing cost low.

 In the scroll compressor according to the sixth aspect of the present invention, it is possible to suppress the contact of the main shaft portion of the crankshaft with respect to the conventional one.

 The scroll compressor according to the seventh aspect of the present invention can suppress the contact of the main shaft portion of the crankshaft with respect to the conventional one.

 The rotary compressor according to the eighth aspect of the present invention can suppress the contact of the main shaft portion of the crankshaft as compared with the conventional one.

 In the rotary compressor according to the ninth aspect of the present invention, it is possible to suppress the contact of the main shaft portion of the crankshaft with respect to one piece as compared with the conventional one.

 The swing type rotary compressor according to the tenth aspect of the invention can suppress the contact of the main shaft portion of the crankshaft with respect to one piece as compared with the prior art.

 The swing type rotary compressor according to the eleventh aspect of the present invention can suppress the contact of the main shaft portion of the crankshaft with respect to one piece as compared with the prior art.

It is a longitudinal cross-sectional view of the high-low pressure dome type scroll compressor which concerns on 1st Embodiment of this invention. It is an expansion longitudinal cross-sectional view of the bearing housing of the high-low pressure dome type scroll compressor which concerns on 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the rotary compressor which concerns on 2nd Embodiment of this invention. It is a top view of a cylinder block of a rotary compressor concerning a 2nd embodiment of the present invention. It is an expanded longitudinal cross-sectional view of the front head of the rotary compressor which concerns on 2nd Embodiment of this invention. It is an expanded longitudinal cross-sectional view of the rear head of the rotary compressor which concerns on 2nd Embodiment of this invention. It is a top view of the cylinder block of the rocking | swiveling rotary compressor which concerns on the modification of 2nd Embodiment of this invention.

-First embodiment-
The high / low pressure dome type scroll compressor 1 according to the first embodiment of the present invention constitutes a refrigerant circuit together with an evaporator, a condenser, an expansion mechanism, and the like, and gas refrigerant (fluorocarbon refrigerant or carbon dioxide refrigerant) in the refrigerant circuit. 1), and mainly includes a sealed dome-shaped casing 10, a scroll compression mechanism 15, an Oldham ring 39, a crankshaft 17, a drive motor 16, as shown in FIG. 1. The lower main bearing 60, the suction pipe 19, and the discharge pipe 20 are included. Hereinafter, the components of the high / low pressure dome type scroll compressor 1 will be described in detail.

<Details of components of high-low pressure dome type scroll compressor>
(1) Casing The casing 10 includes a substantially cylindrical trunk casing portion 11, a bowl-shaped upper wall portion 12 that covers the upper end of the trunk casing portion 11, and a bowl-shaped bottom that covers the lower end of the trunk casing portion 11. Wall 13. The casing 10 mainly accommodates a scroll compression mechanism 15 that compresses a gas refrigerant and a drive motor 16 that is disposed below the scroll compression mechanism 15. The scroll compression mechanism 15 and the drive motor 16 are connected by a crankshaft 17 arranged so as to extend in the vertical direction in the casing 10. As a result, a gap space 18 is generated between the scroll compression mechanism 15 and the drive motor 16.

(2) Scroll compression mechanism As shown in FIG. 1, the scroll compression mechanism 15 mainly meshes with the bearing housing 23, the fixed scroll 24 arranged in close contact with the bearing housing 23, and the fixed scroll 24. The movable scroll 26 is configured. Hereinafter, the components of the scroll compression mechanism 15 will be described in detail.

a) Bearing Housing As shown in FIG. 2, the bearing housing 23 is mainly formed of a main body portion 23a, a cylindrical bearing portion 32, and a support portion 23b. As shown in FIG. 1, the main body 23a includes a bearing housing recess 31 provided in the center, an annular groove 23c for inserting the Oldham ring 39, a seat 23d of the movable scroll 26, and a bearing housing side passage 48 ( Etc.) are formed. The cylindrical bearing portion 32 is formed with a bearing hole 33 penetrating in the vertical direction. The crankshaft 17 is fitted into the bearing hole 33 through a bearing metal 34 so as to be rotatable. The bearing metal 34 functions as a slide bearing. The support portion 23b extends inward from the main body portion 23a, and is formed so as to support the cylindrical bearing portion 32 at the central portion CP1. The cylindrical bearing portion 32 is designed so that the ratio of the total length (axial length) to the wall thickness is 10 or more. Further, the cylindrical bearing portion 32 is designed so that the upper end portion UP1 and the lower end portion LP1 have substantially the same length. As a result, the upper end portion UP1 and the lower end portion LP1 of the cylindrical bearing portion 32 can be flexed freely. The bearing housing 23 is press-fitted and fixed to the body casing portion 11 over the entire outer circumferential surface of the main body portion 23a in the circumferential direction. That is, the body casing portion 11 and the bearing housing 23 are in close contact with each other in an airtight manner over the entire circumference. For this reason, the inside of the casing 10 is partitioned into a high pressure space 28 below the bearing housing 23 and a low pressure space 29 above the bearing housing 23. Further, the fixed scroll 24 is fastened and fixed to the bearing housing 23 with bolts 38 so that the upper end surface thereof is in close contact with the lower end surface of the fixed scroll 24.

  In the present embodiment, the bearing housing 23 is formed from cast iron having a relatively low carbon content by a semi-molten die casting method. Details of the molding of the bearing housing 23 will be described later.

b) Fixed Scroll The fixed scroll 24 mainly includes an end plate 24a, a spiral (involute) wrap 24b formed on the lower surface P2 of the end plate 24a, and an outer peripheral wall 24c surrounding the wrap 24b. A discharge passage 41 that communicates with the compression chamber 40 (described later) and an enlarged recess 42 that communicates with the discharge passage 41 are formed in the end plate 24a. The discharge passage 41 is formed so as to extend in the vertical direction at the central portion of the end plate 24a. The enlarged recess 42 is formed so as to open on the upper surface P1 of the end plate 24a. And the cover body 44 is fastened and fixed to the upper surface P1 of the fixed scroll 24 with the volt | bolt 44a so that this expansion recessed part 42 may be plugged up. And the expansion chamber 42 which muffles the operation sound of the scroll compression mechanism 15, ie, the muffler space 45, is formed by the cover body 44 covering the enlarged recess 42. The fixed scroll 24 and the lid 44 are sealed by being brought into close contact via a packing (not shown).

c) Movable Scroll As shown in FIG. 1, the movable scroll 26 is mainly formed on an end plate 26a, a spiral (involute) wrap 26b formed on the upper surface of the end plate 26a, and a lower surface P2 of the end plate 26a. It is comprised from the bearing part 26c made and the groove part (not shown) formed in the both ends of the end plate 26a. The movable scroll 26 is supported by the bearing housing 23 by fitting an Oldham ring 39 (described later) into the groove. Further, the eccentric shaft portion 17a of the crankshaft 17 is fitted into the bearing portion 26c. The movable scroll 26 revolves in the bearing housing 23 without being rotated by the rotation of the crankshaft 17 by being incorporated in the scroll compression mechanism 15 in this way. The wrap 26b of the movable scroll 26 is meshed with the wrap 24b of the fixed scroll 24, and a compression chamber 40 is formed between the contact portions of both the wraps 24b and 26b. In the compression chamber 40, the volume between the laps 24b and 26b contracts toward the center as the movable scroll 26 revolves. In the high-low pressure dome type scroll compressor 1 according to the present embodiment, the gas refrigerant is compressed in this way.

d) Others In the scroll compression mechanism 15, a communication passage 46 is formed across the fixed scroll 24 and the bearing housing 23. The communication passage 46 is formed such that a scroll side passage 47 opened in the fixed scroll 24 and a bearing housing side passage 48 opened in the bearing housing 23 communicate with each other. The upper end of the communication passage 46 opens into the enlarged recess 42, and the lower end of the communication passage 46 opens into the lower end surface of the bearing housing 23. In other words, the lower end opening of the bearing housing side passage 48 constitutes a discharge port 49 through which the refrigerant in the communication passage 46 flows out into the gap space 18.

(3) Oldham ring The Oldham ring 39 is a member for preventing the rotation of the movable scroll 26 as described above, and the key portion is fitted into an Oldham groove (not shown) formed in the bearing housing 23. It is. The Oldham groove is an oval groove, and is disposed at a position facing each other in the bearing housing 23.

(4) Crankshaft As shown in FIG. 1, the crankshaft 17 is a substantially cylindrical integrally formed component, and mainly includes an eccentric shaft portion 17 a, a main shaft portion 17 b, a balance weight portion 17 c, and a countershaft. A portion 17d is provided. The eccentric shaft portion 17 a is accommodated in the bearing portion 26 c of the movable scroll 26. The main shaft portion 17 b is accommodated in the bearing hole 33 of the bearing housing 23 via the bearing metal 34. The auxiliary shaft portion 17d is accommodated in the lower main bearing 60.

(5) Drive Motor The drive motor 16 is a DC motor in the present embodiment, and mainly includes an annular stator 51 fixed to the inner wall surface of the casing 10 and a slight gap (air gap) inside the stator 51. The rotor 52 is rotatably accommodated with a passage). The drive motor 16 is arranged such that the upper end of the coil end 53 formed on the upper side of the stator 51 is at substantially the same height as the lower end of the cylindrical bearing portion 32 of the bearing housing 23.

  In the stator 51, a copper wire is wound around a tooth portion, and a coil end 53 is formed above and below. Further, the outer peripheral surface of the stator 51 is provided with core cut portions that are notched at a plurality of locations from the upper end surface to the lower end surface of the stator 51 and at predetermined intervals in the circumferential direction. The core cut portion forms a motor cooling passage 55 extending in the vertical direction between the body casing portion 11 and the stator 51.

  The rotor 52 is drivably coupled to the movable scroll 26 of the scroll compression mechanism 15 via the crankshaft 17 disposed at the axial center of the body casing portion 11. A guide plate 58 that guides the refrigerant that has flowed out of the discharge port 49 of the communication passage 46 to the motor cooling passage 55 is disposed in the gap space 18.

(6) Lower Main Bearing The lower main bearing 60 is disposed in the lower space below the drive motor 16. The lower main bearing 60 is fixed to the body casing portion 11 and supports the auxiliary shaft portion 17 d of the crankshaft 17.

(7) Suction Pipe The suction pipe 19 is for guiding the refrigerant in the refrigerant circuit to the scroll compression mechanism 15 and is fitted into the upper wall portion 12 of the casing 10 in an airtight manner. The suction pipe 19 penetrates the low pressure space 29 in the vertical direction, and an inner end portion is fitted into the fixed scroll 24.

(8) Discharge pipe The discharge pipe 20 is for discharging the refrigerant in the casing 10 to the outside of the casing 10, and is fitted into the body casing portion 11 of the casing 10 in an airtight manner.

<Production method of bearing housing>
In the present embodiment, the bearing housing 23 is manufactured by the following manufacturing method.

(raw materials)
In the present embodiment, the iron material used as the raw material of the bearing housing 23 is C: 2.3 to 2.4 wt%, Si: 1.95 to 2.05 wt%, Mn: 0.6 to 0.7 wt%, P : <0.035 wt%, S: <0.04 wt%, Cr: 0.00 to 0.50 wt%, Ni: 0.50 to 1.00 wt% are added. In addition, the weight ratio here is a ratio with respect to the whole quantity. Here, the “billet” means a material before final molding which is formed into a cylindrical shape or the like by a continuous casting apparatus after the iron material having the above components is once melted in a melting furnace. Here, the contents of C and Si are such that the tensile strength and tensile modulus are higher than those of flake graphite cast iron, and that the fluidity suitable for molding a component having a complicated shape is provided. It is decided to satisfy both. The content of Ni is determined so as to constitute a metal composition suitable for improving the toughness of the metal structure and preventing surface cracks during molding.

(Manufacturing process)
The bearing housing 23 is manufactured through a semi-molten die cast molding process, a heat treatment process, and a final finishing process. Hereinafter, each process is explained in full detail.

a) Semi-molten die-cast molding process In the semi-molten die-cast molding process, first, the billet is heated to a high frequency to be in a semi-molten state. Next, when the billet in the semi-molten state is poured into a predetermined mold, the billet is formed into a desired shape while applying a predetermined pressure with a die casting machine, and a bearing housing base is produced. When the bearing housing base is taken out from the mold and rapidly cooled, the metal structure of the bearing housing base is entirely whitened. Note that the bearing housing base is slightly larger than the finally obtained bearing housing 23, and the bearing housing base becomes the final bearing housing 23 by removing the machining allowance in the final finishing process.

b) Heat treatment step In the heat treatment step, the bearing housing base after the semi-molten die casting step is heat treated. In this heat treatment step, the metal structure of the bearing housing base changes from a whitened structure to a metal structure composed of pearlite / ferrite matrix and granular graphite. The graphitization and pearlization of the whitened structure can be adjusted by adjusting the heat treatment temperature, holding time, cooling rate, and the like. For example, as described in Honda R & D Technical Review Vol.14 No.1 paper "Study on the semi-melting technology of iron", cooling at 0.05 to 0.10 ° C / sec after holding at 950 ° C for 60 minutes By slowly cooling in the furnace at a speed, tensile strength of about 500 MPa to 700 MPa, HB150 (HRB81 (converted value from SAE J417 hardness conversion table)) to HB200 (HRB96 (SAE J417 hardness conversion table) A metal structure having a hardness of the order of conversion))) can be obtained. Such a metal structure is soft and excellent in machinability because it has a ferrite center, but there is a possibility of forming a cutting edge during machining and reducing the tool life. In addition, after holding at 1000 ° C. for 60 minutes, air cooling, and further holding for a predetermined time at a temperature slightly lower than the initial temperature and then air cooling, tensile strength of about 600 MPa to 900 MPa, HB200 (HRB96 (SAE J 417 hardness conversion) Conversion value from table)) to HB250 (HRB105, HRC26 (conversion value from SAE J417 hardness conversion table, HRB105 is a reference value because it exceeds the effective practical range of the test type))) A metal structure can be obtained. In such a metal structure, those having hardness equivalent to flake graphite cast iron have machinability equivalent to flake graphite cast iron, and machinability compared to spheroidal graphite cast iron having equivalent ductility and toughness. Is excellent. In addition, by holding the oil at 1000 ° C. for 60 minutes, cooling with oil, and holding the air at a temperature slightly lower than the initial temperature for a predetermined time and then cooling with air, tensile strength of about 800 MPa to 1300 MPa, HB250 (HRB105, HRC26 (SAE J 417 Conversion value from hardness conversion table, HRB105 is a reference value because it exceeds the effective practical range of test type))-HB350 (HRB122, HRC41 (converted value from SAE J417 hardness conversion table, HRB122) It is possible to obtain a metal structure having a hardness of a reference level because it exceeds the effective practical range of the test type. Such a metal structure is hard because it has a pearlite center and is inferior in machinability, but has excellent wear resistance.

c) Final Finishing Process In the final finishing process, the bearing housing base is machined to complete the bearing housing 23.

<Flow of compressed refrigerant gas during operation of high / low pressure dome type scroll compressor>
When the drive motor 16 is driven, the crankshaft 17 rotates, and the movable scroll 26 performs a revolving operation without rotating. Then, the low-pressure gas refrigerant is sucked into the compression chamber 40 from the peripheral side of the compression chamber 40 through the suction pipe 19 and is compressed as the volume of the compression chamber 40 changes, and becomes a high-pressure gas refrigerant. The high-pressure gas refrigerant is discharged from the central portion of the compression chamber 40 through the discharge passage 41 to the muffler space 45, and then flows out to the gap space 18 through the communication passage 46, and the guide plate 58 and the trunk portion. It flows downward between the inner surface of the casing part 11. When the gas refrigerant flows downward between the guide plate 58 and the inner surface of the body casing portion 11, a part of the gas refrigerant is diverted to form a circle between the guide plate 58 and the drive motor 16. Flow in the direction. At this time, the lubricating oil mixed in the gas refrigerant is separated. On the other hand, the other part of the diverted gas refrigerant flows downward in the motor cooling passage 55, flows to the lower motor space, and then reverses to be connected to the air gap passage between the stator 51 and the rotor 52, or to communicate therewith. It flows upward through the motor cooling passage 55 on the side facing the passage 46 (left side in FIG. 1). Thereafter, the gas refrigerant that has passed through the guide plate 58 and the gas refrigerant that has flowed through the air gap passage or the motor cooling passage 55 merge in the gap space 18 and are discharged from the discharge pipe 20 to the outside of the casing 10. The gas refrigerant discharged to the outside of the casing 10 circulates through the refrigerant circuit, and is again sucked into the scroll compression mechanism 15 through the suction pipe 19 and compressed.

<Characteristics of high / low pressure dome type scroll compressor>
In the high / low pressure dome type scroll compressor 1 according to the first embodiment of the present invention, in this bearing housing, the support portion 23b extends obliquely downward and inward from the main body portion 23a, and the cylindrical bearing portion 32 is located at the center. It is supported by the part CP1. The bearing housing 23 is molded from cast iron having a carbon content of 2.3 wt% to 2.4 wt% by a semi-molten die cast molding method or a semi-solid die casting method. As a result, the cylindrical bearing portion 32 is designed so that the ratio of the total length to the wall thickness is 10 or more. For this reason, the upper end portion UP1 and the lower end portion LP1 of the cylindrical bearing portion 32 of the bearing housing 23 can freely bend and follow the behavior of the crankshaft 17 in the radial direction. Therefore, in the high / low pressure dome type scroll compressor 1, it is possible to suppress the one-sided contact of the main shaft portion 17b of the crankshaft 17 as compared with the related art.

<Modification>
(A)
Although the bearing housing 23 according to the previous embodiment was formed from laser-weldable cast iron having a carbon content of 2.3 to 2.4 wt%, the bearing housing 23 is less than 0.3 wt% carbon. You may shape | mold from the low carbon steel which has content. In such a case, the same effect as in the previous embodiment can be obtained.

(B)
The bearing housing 23 according to the previous embodiment was formed from cast iron having a carbon content of 2.3 to 2.4 wt% by a semi-molten die casting method, but the bearing housing 23 is semi-solidified from the cast iron. You may shape | mold by the die-cast shaping | molding method.

(C)
In the bearing housing 23 according to the previous embodiment, the whole was molded from cast iron having a carbon content of 2.3 to 2.4 wt% by the semi-molten die casting method, but only the cylindrical bearing portion 32 was the same. It may be formed from cast iron by the same forming method, or may be formed from low carbon steel having a carbon content of less than 0.3% by weight. That is, the main body 23a and the support 23b may be formed from other materials, for example, ordinary cast iron such as FC250. In order to form such a bearing housing, a “low carbon steel having a carbon content of less than 0.3% by weight” or a “carbon content of 2.0% by weight to 2.7% by weight” is used in advance. It is necessary to mold a cylindrical bearing portion made of “cast iron” and to prepare the cylindrical bearing portion in a mold of the bearing housing before molding the bearing housing. At this time, it is necessary to prepare so that the position of the cylindrical bearing portion in the bearing housing is the same position as the cylindrical bearing portion 32 of the bearing housing according to the previous embodiment. Even if it does in this way, the effect similar to the high-low pressure dome type scroll compressor 1 which concerns on previous embodiment can be acquired.

(D)
The bearing housing 23 according to the previous embodiment is formed from cast iron having a carbon content of 2.3 to 2.4 wt% by a semi-molten die casting method. However, the bearing housing 23 is formed from spheroidal graphite cast iron. May be.

(E)
In the bearing housing 23 according to the previous embodiment, the whole was molded from cast iron having a carbon content of 2.3 to 2.4 wt% by a semi-molten die casting method. The body part 23a and the support part 23b may be formed from flake graphite cast iron. In order to mold such a bearing housing, a cylindrical bearing portion made of spheroidal graphite cast iron is molded in advance, and the cylindrical bearing portion is charged into the bearing housing mold before molding the bearing housing. It is necessary to keep. At this time, it is necessary to prepare so that the position of the cylindrical bearing portion in the bearing housing is the same position as the cylindrical bearing portion 32 of the bearing housing according to the previous embodiment.
-Second embodiment-
The rotary compressor 2 according to the second embodiment of the present invention constitutes a refrigerant circuit together with an evaporator, a condenser, an expansion mechanism, and the like, and includes a gas refrigerant (including a chlorofluorocarbon refrigerant and a carbon dioxide refrigerant) in the refrigerant circuit. As shown in FIG. 3, mainly from a sealed dome-shaped casing 110, a rotary compression mechanism 115, a drive motor 116, a crankshaft 117, a suction pipe 119, and a discharge pipe 120. It is configured. Hereinafter, the components of the rotary compressor 2 will be described in detail.

<Details of components of rotary compressor>
(1) Casing The casing 110 includes a substantially cylindrical trunk casing portion 111, a bowl-shaped upper wall portion 112 that is airtightly welded to the upper end portion of the trunk casing portion 111, and a lower end of the trunk casing portion 111. And a bowl-shaped bottom wall portion 113 that is welded in an airtight manner. The casing 110 mainly accommodates a rotary compression mechanism 115 that compresses a gas refrigerant and a drive motor 116 that is disposed above the rotary compression mechanism 115. The rotary compression mechanism 115 and the drive motor 116 are connected by a crankshaft 117 that is disposed so as to extend in the vertical direction in the casing 110.

(2) Rotary compression mechanism As shown in FIG. 4, the rotary compression mechanism 115 mainly includes a cylinder block 124, a roller 121, a vane 122, a front head 123, and a rear head 125. Hereinafter, the components of the rotary compression mechanism 115 will be described in detail.

a) Cylinder Block As shown in FIG. 4, the cylinder block 124 is formed with a cylinder hole 124a, a suction hole 124b, a discharge passage 124c, and a vane accommodation hole 124d. As shown in FIG. 4, the cylinder hole 124 a is a cylindrical hole that penetrates along the plate thickness direction. As shown in FIG. 4, the suction hole 124b extends from the outer peripheral wall surface to the cylinder hole 124a. The discharge passage 124c is formed by cutting out a part of the inner peripheral side of the cylindrical portion that forms the cylinder hole 124a. The vane accommodation hole 124d is a hole penetrating along the plate thickness direction, and is located between the suction hole 124b and the discharge passage 124c when viewed along the plate thickness direction.

 In the cylinder block 124, a roller 121 and an eccentric shaft portion 117a of a crankshaft 117 (to be described later) are accommodated in a cylinder hole 124a, and a discharge passage 124c is disposed in a state where the vane 122 is accommodated in a vane accommodation hole 124d. The front head 123 and the rear head 125 are fitted to face the side 123 (see FIG. 3). As a result, a cylinder chamber Rc1 is formed in the rotary compression mechanism 115, and this cylinder chamber Rc1 is partitioned by a vane 122 described later into a suction chamber that communicates with the suction hole 124b and a discharge chamber that communicates with the discharge passage 124c. It will be.

b) Roller The roller 121 is inserted into the cylinder hole 124a of the cylinder block 124 while being fitted to an eccentric shaft portion 117a of the crankshaft 117 described later. When the crankshaft 117 rotates, the roller 121 performs a revolving motion around the main shaft portion 117b of the crankshaft 117 while the outer peripheral portion is in sliding contact with the inner wall of the cylinder block 124.

c) Vane The vane 122 is a substantially flat plate-like member, and is always pressed against the roller 121 that revolves by the elastic force of the spring 126 stored in the innermost part of the vane accommodation hole 124d. The vane 122 moves forward and backward while contacting the outer peripheral portion of the roller 121 in accordance with the revolving motion of the roller 121. As a result, the vane 122 partitions the cylinder chamber Rc1 into a suction chamber and a discharge chamber. Here, the suction chamber is in a low pressure state because it communicates with the suction hole 124b, and the discharge chamber is in a high pressure state because it communicates with the discharge passage 124c.

d) Front Head The front head 123 is a member that covers the discharge path 124c side of the cylinder block 124, and is fitted to the casing 110. As shown in FIG. 5, the front head 123 is mainly formed of a main body portion 123a, a cylindrical bearing portion 132a, and a support portion 123b. The cylindrical bearing portion 132a has a bearing hole 133a penetrating in the vertical direction. A crankshaft 117 (to be described later) is rotatably fitted in the bearing hole 133a. The support portion 123b extends inward from the main body portion 123a, and is formed so as to support the cylindrical bearing portion 132a with the central portion CP2. The cylindrical bearing portion 132a is designed so that the ratio of the total length (axial length) to the wall thickness is 10 or more. The cylindrical bearing portion 132a is designed such that the upper end portion UP2 is longer than the lower end portion LP2. As a result, the upper end portion UP2 of the cylindrical bearing portion 132a disposed in the vicinity of the drive motor 116 can bend more freely than the lower end portion LP2. A groove-like space is formed between the main body portion 123a and the lower end portion LP2 of the cylindrical bearing portion 132a. In order to prevent a decrease in compression efficiency, the front head 123 is formed so that the groove-shaped space does not communicate with the cylinder chamber Rc1.

 In the present embodiment, the molding material and molding method of the front head 123 are the same as the molding material and molding method described in regard to the bearing housing 23 in the “Bearing housing manufacturing method” section of “—first embodiment”. Are the same.

e) Rear Head The rear head 125 is a member that covers the opposite side of the cylinder block 124 to the discharge path 124c side. As shown in FIG. 6, the rear head 125 is mainly formed of a main body portion 125a, a cylindrical bearing portion 132b, and a support portion 125b. The cylindrical bearing portion 132b is formed with a bearing hole 133b penetrating in the vertical direction. And the countershaft part 117c of the crankshaft 117 mentioned later is inserted in this bearing hole 133b. The support part 125b extends inward from the main body part 125a, and is formed so as to support the cylindrical bearing part 132b with the central part CP3. The cylindrical bearing portion 132b is designed so that the ratio of the total length (axial length) to the wall thickness is 10 or more. The cylindrical bearing portion 132b is designed such that the lower end portion LP3 is longer than the upper end portion UP3. A groove-like space is formed between the main body portion 125a and the upper end portion UP3 of the cylindrical bearing portion 132b. In order to prevent a reduction in compression efficiency, the rear head 125 is formed so that the groove-shaped space does not communicate with the cylinder chamber Rc1.

 In the present embodiment, the molding material and molding method of the rear head 125 are the same as the molding material and molding method described with respect to the bearing housing 23 in the section “Bearing Housing Manufacturing Method” in “-First Embodiment”. It is.

(3) Drive motor The drive motor 116 has the same configuration as that described with respect to the drive motor 16 in the section “Details of components of the high / low pressure dome type scroll compressor” of “—First Embodiment”. ing.

(4) Crankshaft The crankshaft 117 is mainly formed of a main shaft portion 117b, an eccentric shaft portion 117a, and a sub shaft portion 117c. The eccentric shaft portion 117a is provided on the auxiliary shaft portion 117c side. The countershaft portion 117c is designed to have a diameter smaller than that of the main shaft portion 117b, and the roller 121 is inserted from the side of the subshaft portion 117c and is fitted to the eccentric shaft portion 117a. The crankshaft 117 is fixed to the rotor of the drive motor 116 on the side where the eccentric shaft portion 117a is not provided.

(5) Suction Pipe The suction pipe 119 is provided so as to penetrate the casing 110, and one end is fitted into the suction hole 124 b formed in the cylinder block 124, and the other end is fitted into the accumulator 190. . The suction pipe 119 is for guiding the refrigerant in the refrigerant circuit to the rotary compression mechanism 115.

(6) Discharge Pipe The discharge pipe 120 is provided so as to penetrate the upper wall portion 112 of the casing 110. The discharge pipe 120 is for discharging the refrigerant in the casing 110 to the outside of the casing 110.

<Flow of compressed refrigerant gas during rotary compressor operation>
When the drive motor 116 is driven, as described above, the roller 121 performs a revolution operation around the main shaft portion 117b of the crankshaft 117. As a result, the low-pressure gas refrigerant sucked into the suction chamber through the suction pipe 119 is compressed to become high-pressure gas refrigerant in the discharge chamber, and then discharged out of the casing 110 through the discharge passage 124c.

<Characteristics of rotary compressor>
In the rotary compressor 2 according to the second embodiment of the present invention, for the reason described in the section “Characteristics of the high and low pressure dome type scroll compressor” in “—First Embodiment”, the crankshaft 117 is more The contact of the main shaft portion 117b can be suppressed.

<Modification>
(A)
In the previous embodiment, the front head 123 and the rear head 125 are employed in the rotary compressor 2, but may be employed in a swinging rotary compressor. A plan view of the cylinder block 224 provided in the oscillating rotary compressor 3 is shown in FIG.

  In FIG. 7, in the cylinder block 224, the eccentric shaft portion 217a of the crankshaft and the roller portion 221a of the piston 221 are accommodated in the cylinder hole 224a, and the blade portion 221b and the bush 222 of the piston 221 are accommodated in the bush accommodation hole 224d. In a state where the blade portion 221b of the piston 221 is accommodated in the blade accommodation hole 224e, the discharge passage 224c is fitted to the front head and the rear head so as to face the front head side. As a result, a cylinder chamber Rc2 is formed, and the cylinder chamber Rc2 is partitioned by the piston 221 into a suction chamber communicating with the suction hole 224b and a discharge chamber communicating with the discharge passage 224c. In this state, the roller portion 221a is fitted into the eccentric shaft portion 217a.

 When a drive motor (not shown) is driven, the roller portion 221a performs a revolution operation around the main shaft portion 217b of the crankshaft 217. As a result, the low-pressure gas refrigerant sucked into the suction chamber through the suction hole 224b is compressed to become high-pressure gas refrigerant in the discharge chamber, and then discharged out of the casing through the discharge passage 224c.

(B)
Although the rotary compressor 2 according to the previous embodiment is a one-cylinder type rotary compressor, the bearing housing according to the present invention is employed in a two-cylinder type rotary compressor and a swinging rotary compressor. May be. Note that the distance between the front head and the rear head is longer in the two-cylinder type rotary compressor and the oscillating rotary compressor than in the one-cylinder type rotary compressor and the oscillating rotary compressor. For this reason, in the two-cylinder type rotary compressor and the oscillating rotary compressor, compared to the one-cylinder type rotary compressor and the oscillating rotary compressor, the crankshaft main shaft portion is more likely to hit one side. There's a problem. Such a problem can be solved in the rotary compressor and the oscillating rotary compressor in which the bearing housing according to the present invention is introduced into both the front head and the rear head.

 In addition, since the cylinder chamber is divided into two in the two-cylinder type rotary compressor and the oscillating rotary compressor, the compression mechanism is provided in comparison with the one-cylinder type rotary compressor and the oscillating rotary compressor. It can be downsized. Accordingly, since the total area of the seal portion is reduced in the two-cylinder type rotary compressor and the oscillating rotary compressor compared to the one-cylinder type rotary compressor and the oscillating rotary compressor, the seal of the compression mechanism Can be improved. Therefore, in the two-cylinder type rotary compressor and the oscillating rotary compressor, an improvement in performance is expected compared to the one-cylinder type rotary compressor and the oscillating rotary compressor.

  The bearing housing according to the present invention has a feature that it can suppress the contact of the main shaft portion of the crankshaft more than before, and is adopted for a scroll compressor, a rotary compressor, a swinging rotary compressor, and the like. This contributes to longer compressor life.

1 High / low pressure dome type scroll compressor (scroll compressor)
2 Rotary compressor 3 Oscillating rotary compressor 16, 116 Drive motor (rotary drive mechanism)
17, 117, 217 Crankshaft (Crankshaft)
17a, 117a, 217a Eccentric shaft portion 17b, 117b, 217b Main shaft portion 23 Bearing housing 23a Main body portion 23b Support portion 24 Fixed scroll (first scroll)
26 Movable scroll (second scroll)
26c Bearing part of movable scroll 32 Cylindrical bearing part CP1 Central part 121 of cylindrical bearing part Roller 122 Vane 123,223 Front head (first bearing housing)
124,224 Cylinder blocks 125,225 Rear head (second bearing housing)
221 Piston 221a Roller part 221b Blade part

JP 2003-206873 A

Claims (11)

A cylindrical body (23a);
A cylindrical bearing (32) located inside the main body in plan view;
A bearing housing (23) comprising a support portion (23b) extending from a central portion (CP1) of the cylindrical bearing portion to the main body portion and supporting the cylindrical bearing portion on the main body portion. 2. The cylindrical bearing portion according to claim 1, wherein the cylindrical bearing portion is formed from cast iron having a carbon content of 2.0 wt% to 2.7 wt% by a semi-molten die casting method or a semi-solid die casting method. Bearing housing. The bearing body according to claim 2, wherein the main body portion and the support portion are made of flake graphite cast iron or spheroidal graphite cast iron. The bearing housing according to claim 1, wherein the cylindrical bearing portion is formed of spheroidal graphite cast iron. The bearing body according to claim 4, wherein the main body portion and the support portion are made of flake graphite cast iron. The first scroll (24);
A second scroll (26) having a bearing portion (26c) and pivoting relative to the first scroll in a state of meshing with the first scroll;
A bearing housing (23) according to any of claims 1 to 5;
A crankshaft (17) having an eccentric shaft portion (17a) fitted into the bearing portion of the second scroll and a main shaft portion (17b) inserted through the cylindrical bearing portion of the bearing housing;
A scroll compressor (1) provided with the rotation drive mechanism (16) which rotationally drives the said crankshaft. The scroll compressor according to claim 6 which compresses carbon dioxide. A cylinder block (124) having a cylindrical hole penetrating the center along the thickness direction;
A first bearing housing (123) comprising the bearing housing according to any one of claims 1 to 5 and provided at a position adjacent to the cylinder block along the plate thickness direction;
A position comprising the bearing housing according to any one of claims 1 to 5, provided at a position adjacent to the cylinder block along a plate thickness direction, and fitting the cylinder block with the first bearing housing. A second bearing housing (125) provided in the
A roller (121) disposed in a compression space surrounded by the cylinder block, the first bearing housing and the second bearing housing;
A vane (122) that slidably contacts the roller and divides the compression space into two spaces;
A crankshaft (117) having an eccentric shaft portion (117a) into which the roller is rotatably inserted, and a main shaft portion (117b) inserted into the cylindrical bearing portion of the first bearing housing;
A rotary compressor (2) provided with the rotation drive mechanism (116) which rotationally drives the said crankshaft. The rotary compressor according to claim 8, which compresses carbon dioxide. A cylinder block (224) having a cylindrical hole penetrating the central portion along the plate thickness direction;
A first bearing housing (223) comprising the bearing housing according to any one of claims 1 to 5, and provided at a position adjacent to the cylinder block along the plate thickness direction;
A position comprising the bearing housing according to any one of claims 1 to 5, provided at a position adjacent to the cylinder block along a plate thickness direction, and fitting the cylinder block with the first bearing housing. A second bearing housing (225) provided in the
A roller portion (221a) disposed in a compression space surrounded by the cylinder block, the first bearing housing and the second bearing housing, and a roller portion (221a) formed integrally with the roller portion, and the compression space A piston (221) having a blade portion (221b) partitioned into two spaces;
A crankshaft (217) having an eccentric shaft portion (217a) into which the roller portion is rotatably fitted, and a main shaft portion (217b) inserted into the cylindrical bearing portion of the first bearing housing;
A oscillating rotary compressor (3) provided with a rotational drive mechanism for rotationally driving the crankshaft. The oscillating rotary compressor according to claim 10, which compresses carbon dioxide.

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