JP2006312952A - Antifriction bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antifriction bearing device capable of reducing foreign matter intruding into the device and securing durability over a long time even if it is exposed to an environment such as water vapor. <P>SOLUTION: In the antifriction bearing device provided with a cylindrical housing 2, a rotary shaft 3 which is inserted into the housing 2 and to which compressor parts are fixed, an inner ring 13 press-fitted to the rotary shaft 3, an outer ring 12 clearance-fitted to the housing 2, and a pair of antifriction bearings 4 having a plurality of rolling elements 15 freely rollably received between these inner and outer rings, since the inner ring 13 and the outer ring 12 of the antifriction bearing 4 are formed out of M50, the rolling elements 15 is formed out of an austenitic stainless steel, and also, an annular groove 22 is formed on the outer periphery of the outer ring 12, and an elastic ring 23 is fitted to this annular groove 22 to come into elastic contact with the housing 2, intrusion of foreign matter into the inside of the antifriction bearing device is prevented and its durability can be secured even if it is exposed to an environment such as water vapor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rolling bearing device that supports a rotating shaft to which components such as an impeller compressor are fixed, and more particularly to a rolling bearing device used in a compressor device for a fuel cell.

  A fuel cell is a power generation device that takes out electric energy by chemically reacting hydrogen and oxygen supplied from the outside, and is a solid that is generally applied to, for example, a fuel cell for an automobile by an electrolyte used in the fuel cell. It is classified into a polymer type, a phosphate electrolyte type, a molten carbonate type, and a solid oxide type. Regardless of the type of fuel cell, both sides of the electrolyte or electrolyte membrane are sandwiched between both cathode (oxygen electrode) and anode (fuel electrode) electrodes, and oxygen in the air is supplied as the oxidant gas to the cathode side. At the same time, a unit cell in which hydrogen is supplied as fuel gas to the anode side is formed as a single cell, and each cell through separators is stacked to form a stack.

  There are a turbocharger system in which the compressor is driven by an exhaust gas turbine and a motor drive system in which the compressor is driven by a motor in order to supply air by pumping to the cathode side of such a fuel cell. Further, when supplying oxygen and hydrogen to the fuel cell, for example, in the case of a solid polymer type or the like, it is necessary to react by adding water vapor even in a direct hydrogen type that uses hydrogen directly as a fuel. Furthermore, for example, in a reformed fuel type using gasoline or the like as the fuel, very high temperature steam is required. Since water vapor is required in this way, a compressor that pumps water vapor is generally used for the purpose of increasing energy efficiency.

  In this compressor, a rolling bearing is used to rotatably support the impeller attached to the rotating shaft. However, when the back space of the impeller changes from negative pressure to positive pressure, water vapor enters the rolling bearing. There is. In general, the inner ring on the rotating side of the rolling bearing and the shaft of the rotating shaft have an interference fit, and the outer ring and the housing on the fixed side have a clearance fit. Water vapor or the like may roll from the gap and enter the bearing device.

  As a solution to this problem, a rolling bearing device shown in FIG. 4 is known. The rolling bearing device 50 includes a housing 51, a rotating shaft 52 fitted in the housing 51, and a pair of rolling bearings 53 and 54 that rotatably support the rotating shaft 52 with respect to the housing 51. .

  One end portion of the rotating shaft 52 protrudes from one rolling bearing 53, and an impeller 55 is attached to the tip side thereof. A seal portion is provided between the back surface of the impeller 55 and the rolling bearing 53. The seal portion is disposed between a bush 56 extrapolated to the rotating shaft 52, a sealing member 57 mounted in a groove formed on the outer peripheral surface of the bush 56, and the back plate 58 and the rolling bearing 53. Baffle 59. Here, the sealing member 57 seals a gap between the outer peripheral surface of the bush 56 and the inner peripheral surface of the back plate 58. Further, the end of the bush 56 is in contact with the side surface of the inner ring 53 b of the rolling bearing 53.

  In the rolling bearing device 50, the impeller 55 rotates as the rotating shaft 52 rotates at high speed, and the water vapor sucked from the water vapor suction port 60 is pressurized by the impeller 55, and is formed by the impeller housing 61 and the back plate 58. The steam is discharged from the steam outlet 63 through the pressure volute 62.

Here, in the pair of rolling bearings 53 and 54, the inner ring 53b and 54b side is an interference fit with the rotary shaft 52, but the outer ring 53a and 54a side is a clearance fit with the housing 51. As shown in FIG. 5, an annular groove 64 is formed on the outer peripheral surfaces of the outer rings 53 a and 54 a, and an O-ring 65 is attached to the annular groove 64. The O-ring 65 is in close contact with the outer rings 53a and 54a and the housing 51, and the gap generated between the fitting surfaces of both is sealed. Thereby, when the back space 66 of the impeller 55 changes from a negative pressure to a positive pressure, it is possible to prevent water vapor or the like from entering the pair of rolling bearings 53 and 54.
JP 2003-202018 A

  As described above, in the conventional rolling bearing device 50, the annular groove 64 is formed on the outer peripheral surface of the outer ring 53a, 54a to be a clearance fit with the housing 51, and the O-ring 65 is attached to the annular groove 64. Although it is possible to prevent water vapor and the like from entering through the gaps between the fitting portions of the rolling bearings 53 and 54, these rolling bearings 53 and 54 are usually formed of high carbon chrome steel such as SUJ2, If exposed to an atmosphere such as water vapor for a long time, rust may be generated on the bearing surface. In addition, when corrosion occurs, it is not preferable because peeling accompanied by a change in white structure caused by diffusible hydrogen existing in the environment, that is, so-called “brittle peeling” is likely to occur.

  The present invention has been made in view of such circumstances, and is a rolling bearing that reduces foreign matters entering the inside of the rolling bearing device and can ensure durability over a long period of time even when exposed to an atmosphere such as water vapor. The object is to provide a device.

  In order to achieve the object, the invention according to claim 1 of the present invention is a rolling bearing device used in a compressor device of a fuel cell, and is a cylindrical housing, and is fitted into the housing, and the compressor device is A rotating shaft to which the components are fixed, an inner ring press-fitted into the rotating shaft, an outer ring fitted in the housing, and a plurality of rolling elements that are rotatably accommodated between the inner and outer rings. In the rolling bearing device in which the rotating shaft is rotatably supported with respect to the housing by the rolling bearing, the inner ring and the outer ring of the rolling bearing have high hardness and are excellent in brittle peeling resistance. The rolling element is made of a material excellent in corrosion resistance and brittle peeling resistance.

  As described above, in a rolling bearing device that is used in a fuel cell compressor device and includes a rolling bearing that rotatably supports a rotating shaft on which a compressor device component is fixed with respect to a cylindrical housing. The inner ring and outer ring are made of heat-resistant steel with high hardness and excellent brittle peel resistance, and the rolling elements are made of a material with excellent corrosion resistance and brittle peel resistance. However, it is possible to provide a rolling bearing device that prevents the occurrence of rust, improves the fatigue life and seizure resistance life, and can ensure durability over a long period of time.

  Moreover, if the said inner ring | wheel and outer ring | wheel are formed with M50 like invention of Claim 2, high hardness is obtained, it is excellent in brittle-proof peeling, and a fatigue life can be improved.

  In addition, if the rolling element is made of ceramics as in the invention described in claim 3, the corrosion resistance is excellent, and the seizure life is improved.

  If the rolling element is made of austenitic stainless steel as in the invention described in claim 4, it has excellent corrosion resistance and high hardness, and suppresses wear and improves durability. Can be made.

  Further, as in the invention described in claim 5, the rolling bearing is constituted by a pair of rolling bearings, and an annular groove is formed on an outer ring of at least the compressor-side rolling bearing among the pair of rolling bearings, If an elastic ring is attached to the annular groove and is in elastic contact with the housing, foreign matter can be prevented from entering the inside of the pair of rolling bearings through the fitting portion between the outer ring and the housing. it can.

  A rolling bearing device according to the present invention is a rolling bearing device used in a compressor device for a fuel cell, and includes a cylindrical housing, a rotary shaft that is fitted in the housing, and to which the components of the compressor device are fixed, A rolling bearing having an inner ring press-fitted into the rotating shaft, an outer ring fitted in the housing, and a plurality of rolling elements that are rotatably accommodated between the inner and outer rings. In the rolling bearing device in which the rotating shaft is rotatably supported with respect to the housing, the inner ring and the outer ring of the rolling bearing are formed of heat-resistant steel having high hardness and excellent brittle peeling, and Since the rolling elements are made of a material with excellent corrosion resistance and brittleness resistance, rust is prevented even when exposed to an atmosphere such as water vapor, and fatigue life and seizure life are improved. It is possible to provide a rolling bearing device capable of securing the durability for a long period of time Te.

  A rolling bearing device used for a compressor device of a fuel cell, a cylindrical housing, a rotating shaft that is fitted into the housing and to which parts of the compressor device are fixed, and an inner ring that is press-fitted into the rotating shaft, A rolling bearing having an outer ring fitted in the housing and a plurality of rolling elements that are rotatably accommodated between the inner and outer rings, and the rotating shaft with respect to the housing by the rolling bearing. In the rolling bearing device that is rotatably supported, the inner ring and the outer ring of the rolling bearing are formed of M50, the rolling element is formed of austenitic stainless steel, and an annular groove is formed in the outer ring. An elastic ring is mounted in the groove and is in elastic contact with the housing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a first embodiment of a rolling bearing device according to the present invention, and FIG. 2 is an enlarged view of a main part showing a bearing portion of FIG. In the following description, the compressor component (impeller) side is referred to as an inboard side (left side in the drawing), and the external side is referred to as an outboard side (right side in the drawing).
The rolling bearing device 1 includes a housing 2, a rotating shaft 3 fitted into the housing 2, and a pair of rolling bearings 4 and 5 that rotatably support the rotating shaft 3 with respect to the housing 2. .

  One end portion of the rotating shaft 3 protrudes from the inboard side rolling bearing 4, and an impeller 7 is attached to the tip end side via a fixing nut 6. The housing 2 includes a cylindrical housing body 2a and a lid member 21 attached to an end portion on the outboard side of the housing body 2a. A shaft seal 21 a slidably contacting the rotating shaft 3 is attached to the inner periphery of the lid member 21, and the opening of the housing 2 is closed. A small-diameter portion 2b is formed on the inner periphery of the housing body 2a on the inboard side, and is opposed to the shoulder portion 3a of the rotating shaft 3 through a slight radial clearance to form a so-called labyrinth seal 8. The labyrinth seal 8 closes the back space 7 a of the impeller 7 and the rolling bearing 4.

  In this rolling bearing device 1, the impeller 7 rotates as the rotating shaft 3 rotates at high speed, and water vapor sucked from the water vapor suction port 9 is pressurized by the impeller 7, and is formed by the impeller housing 10 and the housing 2. It is pumped through the pressure volute 11.

  Here, the pair of rolling bearings 4 and 5 are deep groove ball bearings, and as shown in an enlarged view in FIG. 2, an outer ring 12 having an outer rolling surface 12a formed on the inner periphery and an inner rolling surface 13a on the outer periphery. Formed on the inner ring 13, rolling elements (balls) 15 accommodated between both rolling surfaces 12 a and 13 a via a cage 14, and seals 16 attached to both ends of the outer ring 12, 16. The seals 16 and 16 prevent the lubricating grease sealed inside the bearing from leaking to the outside and prevent foreign matters such as water vapor from entering the bearing from the outside.

  Spacers 17 and 18 are mounted between the outer rings 12 and 12 and between the inner rings 13 and 13, and the pair of rolling bearings 4 and 5 are positioned. That is, the pair of outer rings 12, 12 are positioned and fixed in the axial direction while being sandwiched between the spacer 17, the housing body 2 a and the lid member 21, and the pair of inner rings 13, 13 are connected to the spacer 18 and the rotating shaft. 3 is positioned and fixed in a state of being clamped by a shoulder nut 3a and a fixing nut 6 screwed to the outboard side (see FIG. 1). The pair of rolling bearings 4 and 5 may be angular ball bearings, and preload may be applied to the rolling bearings 4 and 5 by the spacers 17 and 18. Thereby, the touch of the rotating shaft 3 can be suppressed and the rigidity of the rolling bearing device 1 can be improved.

  The seal 16 of the rolling bearing 4 (5) includes a steel plate metal core 19 having a substantially L-shaped cross section, and a seal member 20 made of an elastic member such as rubber, which is vulcanized and bonded to the metal core 19. It has. The seal member 20 integrally has seal lips 20a and 20b formed in a bifurcated shape at the inner edge portion, and constitutes a contact seal.

  The seal member 20 is made of polyacryl rubber, fluorine rubber, or ethylene / propylene rubber having excellent heat resistance and chemical resistance. Among them, ethylene / propylene rubber is a kind of olefin rubber, and there are two types, EPM, which is a copolymer of ethylene and propylene, and EPDM, which is a terpolymer of ethylene, propylene and a diene monomer for crosslinking. is there. In particular, EPDM is capable of sulfur crosslinking (vulcanization) by copolymerizing a third component, which is a non-conjugated diene monomer, and has durability against natural gas, methanol, or a gas such as acetone. Compared with fluorine rubber, which is weak, it has chemical resistance equivalent to polyacrylic rubber at low cost. Thereby, in long-term driving | operation, deterioration and abrasion of the seal | sticker 16 by organic gas can be prevented, and it can prevent that water vapor | steam etc. penetrate | invade inside a bearing.

  Here, in the pair of rolling bearings 4 and 5, the inner ring 13 side is an interference fit with the rotating shaft 3, while the outer ring 12 side is an interference fit with the housing 2. An annular groove 22 is formed at least on the outer circumferential surface of the outer ring 12 of the inboard side rolling bearing 4, and an elastic ring 23 made of an O-ring or the like is elastically attached to the annular groove 22. The elastic ring 23 is in close contact with the outer ring 12 and the housing 2, and the gap between them is sealed. Thereby, when the back space 7a of the impeller 7 changes from a negative pressure to a positive pressure, it is possible to prevent water vapor or the like from entering the pair of rolling bearings 4 and 5.

  The outer ring 12 and the inner ring 13 of the rolling bearing 4 (5) are made of heat-resistant steel having high hardness and excellent brittle peeling resistance. Examples of the heat-resistant steel include AMS6491 and ferritic heat-resistant steel (such as JIS standard SUH446). AMS6491, commonly known as AISI M50 (precise-hardening type high-alloy steel with high hardness and excellent resistance to brittle peeling. 4Cr-4Mo-1V-0.8C) is preferred.

The rolling elements 15 are made of ceramics excellent in corrosion resistance and brittle peeling or stainless steel having corrosion resistance. Examples of ceramic materials include metal oxides such as alumina (Al ₂ O ₃ ), zirconia, silicon nitride, silicon carbide, titanium oxide (TiO ₂ ), and chromium oxide (Cr ₂ O ₃ ). it can. Examples of the stainless steel include austenitic stainless steel (JIS standard SUS304 series, etc.), martensitic stainless steel (JIS standard SUS440 series, etc.), ferritic stainless steel (JIS standard SUS430 series, etc.) and the like. However, an austenitic stainless steel that is excellent in corrosion resistance, has high hardness with a non-magnetic material, and can suppress wear is preferable.

  The retainer 14 can be exemplified by a stainless steel plate having a corrosion resistance or a material made of a fluorine-based resin. Like the rolling element 15, an austenitic stainless steel plate (JIS standard SUS304, etc.) having excellent corrosion resistance is pressed. Those formed by processing are preferred.

  In the present embodiment, the outer ring 12 and the inner ring 13 of the rolling bearing 4 (5) are formed of AISI M50, and the rolling element 15 is formed of ceramics or corrosion-resistant stainless steel, so that it is exposed to an atmosphere such as water vapor. Further, it is possible to provide the rolling bearing device 1 that prevents the occurrence of rust, improves the fatigue life and seizure life, and can ensure the durability over a long period of time.

  FIG. 3 is an enlarged view of a main part showing a second embodiment of the rolling bearing device according to the present invention. This embodiment differs from the second embodiment (FIG. 3) described above only in the configuration of the outer ring and the seal, and the same reference numerals are given to the same parts, the same parts, or parts having the same function. Detailed description thereof will be omitted.

  The rolling bearing 24 includes an outer ring 25 having an outer rolling surface 12a formed on the inner periphery, an inner ring 13 having an inner rolling surface 13a formed on the outer periphery, and a cage 14 between the rolling surfaces 12a and 13a. The rolling element 15 is movably accommodated via the outer ring 25, and the seals 26 and 26 are attached to both ends of the outer ring 25.

  The seal 26 includes a steel core 19 made of a steel plate having a substantially L-shaped cross section, and a seal member 27 vulcanized and bonded to the core 19 and made of an elastic member such as rubber. The seal member 27 integrally has a seal lip 27a along the seal groove 13b of the inner ring 13 at the inner edge, and constitutes a labyrinth seal with the seal groove 13b.

  In the present embodiment, the inner ring 13 and the outer ring 25 are formed of AISI M50, and the rolling elements 15 are formed of ceramics or stainless steel having corrosion resistance, as in the above-described embodiment. An annular groove 28 is formed in the width surface of the outer ring 25, and an elastic ring 29 made of an O-ring or the like is elastically attached to the annular groove 28. And this elastic ring 29 closely_contact | adheres to the outer ring | wheel 25 and the shoulder part (not shown) of the housing 2, and the clearance gap between both is sealed. Thereby, when the back space 7a of the impeller 7 changes from a negative pressure to a positive pressure, it is possible to effectively prevent water vapor and the like from entering the pair of rolling bearings.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The rolling bearing device according to the present invention can be applied to a rolling bearing device used in all types of compressor devices for fuel cells.

It is a longitudinal section showing a 1st embodiment of a rolling bearing device concerning the present invention. It is a principal part enlarged view which shows the bearing part of FIG. It is a principal part enlarged view which shows 2nd Embodiment of the rolling bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the conventional rolling bearing apparatus. It is a principal part enlarged view which shows the bearing part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rolling bearing device 2 ... Housing 2a ... Housing body 2b ... ········ Small diameter portion 3 ······································································· ········ Rolling bearing 6 ··············································· ··· Impeller back space 8 ·····································… ..Impeller housing 11 ... Pressure volute 12, 25 ... Outer ring 12a ... Outer rolling surface 13 .... Inner ring 13a・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 13b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal groove 14 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retainer 15 ・ ・ ・ ・ ・ ・ ・ ・.... Rolling elements 16, 26 ... Seals 17, 18 ... Spacer 19 ... Core metal 20, 27 ......... Seal members 20a, 20b, 27a ... Seal lip 21 ... Lid member 21a ... Seals 22, 28... Annular grooves 23, 29... Elastic ring 50.・ ・ ・ ・ ・ ・ ・ ・ Housing 52 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rotating shaft 53, 54 ・ ・ ・ ・ ・ ・ ・ ・ Rolling bearing 53a, 54a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer ring 53b 54b ... Inner ring 5 ... Impeller 56 ... Bushing 57 ... Sealing member 58 ...・ ・ ・ ・ ・ ・ Back plate 59 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Baffle 60 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Water vapor inlet 61 ・ ・ ・ ・ ・ ・ ・ ・· Impeller housing 62 ······· Pressure volute 63 ······························· Groove 65 ········· O-ring 66 ·································································

Claims (5)

A rolling bearing device used in a compressor device of a fuel cell,
A cylindrical housing;
A rotating shaft that is inserted into the housing and to which the components of the compressor device are fixed,
A rolling bearing having an inner ring press-fitted into the rotating shaft, an outer ring fitted in the housing, and a plurality of rolling elements accommodated between the inner and outer rings in a freely rolling manner;
In the rolling bearing device in which the rotating shaft is rotatably supported with respect to the housing by the rolling bearing,
The inner ring and the outer ring of the rolling bearing are formed of heat-resistant steel having high hardness and excellent in brittle peeling, and the rolling elements are formed of a material excellent in corrosion resistance and brittle peeling. Rolling bearing device.   The rolling bearing device according to claim 1, wherein the inner ring and the outer ring are formed of M50.   The rolling bearing device according to claim 1, wherein the rolling element is made of ceramics.   The rolling bearing device according to claim 1, wherein the rolling element is made of austenitic stainless steel.   The rolling bearing is composed of a pair of rolling bearings, and an annular groove is formed in the outer ring of at least the compressor-side rolling bearing of the pair of rolling bearings, and an elastic ring is attached to the annular groove, and the housing The rolling bearing device according to claim 1, which is in elastic contact.

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