JP2010215980A - Heat treatment apparatus for foil type gas bearing and heat treatment method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the generation of damage when a ring member is arranged at a core metal member as much as possible, and further to correct the inside diameter dimensions at high accuracy. <P>SOLUTION: A heat treatment apparatus 20 includes: a cylindrical collar member 22; and the core metal member 24 arranged at the inside of the collar member 22. The inside diameter of the collar member 22 is set so as to be larger than the outside diameter of the ring member 14, and the outside diameter of the core metal member 24 is set so as to be smaller than the inside of the ring member 14. The axial-direction lengths of the collar member 22 and the core metal member 24 are set so as to be longer than the axial-direction length of the ring member 14, and further, the core metal member 24 is composed of a material having a thermal expansion coefficient higher than that of the ring member 14 and the collar member 22. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heat treatment apparatus for a foil-type gas bearing for manufacturing a foil-type gas bearing arranged in the order of a corrugated bump foil and a flat-plate top foil on the inner peripheral surface of a cylindrical ring member, and It relates to the heat treatment method.

  Generally, as a bearing for supporting a rotating shaft that rotates at a high speed, a rotational accuracy can be obtained with a relatively simple configuration. This is a system in which pressure (dynamic pressure) is generated in the lubricating fluid film by the relative sliding motion of the rotating shaft and the bearing to support the bearing load.

  In this type of gas bearing, there is a problem that the manufacturing man-hour increases due to deterioration of the inner diameter accuracy of the bearing, and vibration, noise, heat generation, and the like of the rotating shaft occur. This causes damage to the rotating shaft and a reduction in bearing life.

  Thus, for example, a method for manufacturing a foil bearing disclosed in Patent Document 1 is known. This manufacturing method includes one or a plurality of flexible metal thin films, a metal thin film support member joined to the metal thin film at at least one position of the metal thin film, and an outer frame to which the support member is attached. In the method of manufacturing a foil bearing, a reference rod having a bearing surface corresponding portion whose diameter is larger than the rotating shaft by a predetermined bearing clearance is inserted into a region where the flexible metal thin film surrounds the rotating shaft. The bearing of the metal thin film is pressed against the reference rod by being pressed in contact with the metal thin film by the reference rod and heated in a heat treatment furnace while maintaining this state. A bearing surface having a shape along the peripheral surface of the reference rod is transferred to the surface in the form of permanent deformation.

JP 61-103010 A

  However, in Patent Document 1 described above, the heat treatment is performed in a state where the reference rod is pressed against the metal thin film, but thermal expansion of the reference rod and the metal thin film during the heat treatment is not taken into consideration. For this reason, there is a problem that the inner diameter of the bearing surface obtained after cooling varies. Moreover, since a reference rod having a diameter larger than that of the rotary bearing is inserted into the metal thin film before the heat treatment, the metal thin film may be damaged or deformed.

  The present invention solves this type of problem, and prevents damage from occurring as much as possible when a ring member is disposed on a cored bar member, and can correct the inner diameter dimension with high accuracy. An object of the present invention is to provide a heat treatment apparatus and a heat treatment method for a foil type gas bearing.

  The present invention relates to a heat treatment apparatus for a foil-type gas bearing for manufacturing a foil-type gas bearing arranged in the order of a corrugated bump foil and a flat plate-like top foil on the inner peripheral surface of a cylindrical ring member. Is.

  The heat treatment apparatus includes a cylindrical collar member and a cored bar member disposed inside the collar member, and an inner diameter of the collar member is set larger than an outer diameter of the ring member, and The outer diameter of the metal core member is set smaller than the inner diameter of the ring member.

  The axial lengths of the collar member and the core metal member are set to be longer than the axial length of the ring member, and the core metal member is at least larger than the ring member or the collar member. It is made of a material having a coefficient of thermal expansion.

  The collar member is preferably made of a material having a smaller coefficient of thermal expansion than the ring member.

  Furthermore, the cored bar member is preferably set to a smaller heat capacity than the ring member and the collar member.

  Furthermore, a first lid member and a second lid member are disposed at both ends of the collar member in the axial direction, and the first lid member and the second lid member have holes that communicate with each other in the axial direction. Is preferably formed.

  Preferably, at least the first lid member or the second lid member is provided with a first holding portion that holds the collar member from the inner peripheral side and a second holding portion that holds the cored bar from the center side.

  Furthermore, it is preferable that the first lid member is provided with a first holding part and a second holding part, and the second lid member is provided with only the first holding part.

  Furthermore, the lid member is preferably made of a material having a smaller coefficient of thermal expansion than the cored bar member.

  Further, the present invention provides a heat treatment for a foil gas bearing for manufacturing a foil gas bearing arranged in the order of a corrugated bump foil and a flat plate top foil on the inner peripheral surface of a cylindrical ring member. It is about the method.

  The heat treatment method includes: a cylindrical collar member that is longer than the axial length of the ring member; a core member that is disposed inside the collar member and is longer than the axial length of the ring member; The core having a coefficient of thermal expansion greater than that of at least the ring member or the collar member by heat treatment, and a step of disposing the ring member thinner than the gap to which at least the bump foil is bonded in the gap of Under the expansion action of the gold member, there are a step of correcting the bump foil and a step of shrinking the core metal member in a direction away from the bump foil by cooling.

  In the present invention, since the cored bar member has a larger coefficient of thermal expansion than at least the ring member or the collar member, it is not necessary to set a large outer diameter of the cored bar member at normal temperature. Accordingly, when the ring member is disposed on the cored bar member, for example, damage or deformation of the bump foil can be prevented as much as possible.

  In addition, the collar member and the cored bar member are set to be longer than the axial length of the ring member. For this reason, it becomes possible to correct | amend the whole ring member, ie, the whole bump foil easily and reliably, and can correct an internal diameter dimension with high precision.

  Furthermore, according to the present invention, after the cored bar member is disposed, the cored bar member is expanded by heat treatment, and the bump foil can be corrected. Then, by performing the cooling process, the cored bar member contracts and is separated from the bump foil, and the shape of the bump foil can be favorably maintained.

It is a section explanatory view of the foil type gas bearing to which the heat treatment method concerning the embodiment of the present invention is applied. It is a principal part disassembled perspective explanatory drawing of the heat processing apparatus which concerns on embodiment of this invention. It is sectional explanatory drawing of the said heat processing apparatus. It is explanatory drawing of the state by which the metal core member was arrange | positioned in the said heat processing method. It is explanatory drawing at the time of the heat processing in the said heat processing method. It is explanatory drawing at the time of the cooling in the said heat processing method.

  As shown in FIG. 1, a foil type gas bearing 10 to which a heat treatment method according to an embodiment of the present invention is applied supports a rotating shaft 12 rotatably and a cylindrical ring member 14 fixed so as not to rotate. Is provided. On the inner peripheral surface 14a of the ring member 14, a corrugated bump foil 16 and a flat top foil 18 are arranged in this order.

  The bump foil 16 is composed of one sheet or a plurality of sheets and is welded to the inner peripheral surface 14a. The top foil 18 has a flat plate curved in an annular shape, and one end 18a is welded to the inner peripheral surface 14a, while the other end is a free end (free). In addition, when the bump foil 16 is comprised with a single board | plate material, while the one end 16a is welded to the internal peripheral surface 14a, the other end is a free end. The bump foil 16 and the top foil 18 are made of a thin metal plate having a thickness of about 0.1 mm, for example.

  As shown in FIGS. 2 and 3, the heat treatment apparatus 20 according to the present embodiment includes a cylindrical collar member 22, a core member 24 disposed inside the collar member 22, and a shaft of the collar member 22. The 1st cover member 26 and the 2nd cover member 28 which are arrange | positioned at a direction (arrow A direction) both ends are provided.

  The inner diameter D1 of the collar member 22 is set to be larger than the outer diameter D2 of the ring member 14, and the outer diameter D3 of the cored bar member 24 is set to be smaller than the inner diameter D4 of the ring member 14. The length of the collar member 22 and the cored bar member 24 in the axial direction (arrow A direction) is set to be longer than the length of the ring member 14 in the axial direction.

  The core metal member 24 is made of a material having a larger coefficient of thermal expansion than the ring member 14 and the collar member 22 (or at least one of them). The collar member 22 is made of a material having a smaller coefficient of thermal expansion than the ring member 14.

  The metal core member 24 has a substantially cylindrical shape, and a relatively large diameter opening 30 is formed through the axial direction. The metal core member 24 is set to a heat capacity (heat mass) smaller (including the same) than the ring member 14 and the collar member 22.

  The first lid member 26 has a substantially disk shape, and a plurality of first hole portions 32 are provided on the same circumference with respect to the center of the first lid member 26. An opening 34 is formed at the center of the first lid member 26, and the first holding part 36 and the second holding part 38 are provided concentrically from the outside around the opening 34.

  The first holding portion 36 is configured by an annular protrusion protruding in the axial direction. The first holding portion 36 abuts on the inner peripheral surface 22 a of the collar member 22, and causes the collar member 22 to move to the inner periphery. Hold from the side. Similarly, the second holding portion 38 is formed by an annular protrusion that protrudes in the axial direction, abuts against the inner peripheral surface 24a of the core member 24, and holds the core member 24 from the center side.

  The second lid member 28 has a substantially disk shape, and a plurality of second hole portions 40 are provided on the same circumference with respect to the center thereof. The second hole 40 communicates with the first hole 32 coaxially with each other in the axial direction. An opening 42 is formed on the center side of the second lid member 28, and a first holding part 44 is formed around the opening 42. The 1st holding | maintenance part 44 is comprised by the annular | circular shaped protrusion part which protrudes in an axial direction. The first holding portion 44 engages with the inner peripheral surface 22a of the collar member 22 to hold the collar member 22 from the inner peripheral side.

  The second lid member 28 is not provided with the second holding portion 38 of the first lid member 26. The first lid member 26 and the second lid member 28 are made of a material having a smaller coefficient of thermal expansion than the cored bar member 24.

  The operation of the heat treatment apparatus 20 configured as described above will be described below in relation to the heat treatment method according to the present embodiment.

  First, in the foil type gas bearing 10, the bump foil 16 is welded to the inner peripheral surface 14 a of the ring member 14. The ring member 14 to which the bump foil 16 is welded is disposed in the gap S between the cored bar member 24 and the collar member 22 as shown in FIG.

  FIG. 4 shows the room temperature, and the outer diameter D3 of the cored bar member 24 is set to be smaller than the inner diameter D4 of the ring member 14. Therefore, when the core member 24 is disposed in the ring member 14, the ring member 14, more specifically, the bump foil 16, can be prevented from being damaged or deformed.

  Next, as shown in FIG. 5, the heat treatment apparatus 20 is heated to a predetermined temperature, for example, a temperature of about 1000 ° C., through a heating unit (not shown). At that time, the cored bar member 24 has a larger thermal expansion coefficient than the ring member 14 and the collar member 22. For this reason, at the time of the heat treatment, the cored bar member 24 expands larger than the radial expansion of the ring member 14 and the collar member 22 in the radial direction.

  Thereby, the bump foil 16 welded to the inner peripheral surface 14a of the ring member 14 is pressed and corrected by the outer peripheral surface of the cored bar member 24 that expands greatly in the radial direction.

  Further, after the heat treatment, the heat treatment apparatus 20 is rapidly cooled (for example, rapidly frozen). Therefore, as shown in FIG. 6, the core metal member 24 having a large coefficient of thermal expansion is set to have a smaller heat capacity than the ring member 14 and the collar member 22, and thus contracts more greatly than the ring member 14 and the collar member 22. To do. For this reason, the ring member 14 does not press and correct the bump foil 16 against the cored bar member 24 at the time of rapid cooling, and the bump foil 16 is accurately maintained in a desired shape.

  In this case, in the present embodiment, the cored bar member 24 has a larger coefficient of thermal expansion than the ring member 14 and the collar member 22 (or at least one of them), so that the inner diameter of the cored bar member 24 at normal temperature is set large. There is no need to do. Therefore, as shown in FIG. 4, when the cored bar member 24 is arranged, damage and deformation of the bump foil 16 welded to the inner peripheral surface 14a of the ring member 14 can be prevented as much as possible. An effect is obtained.

  Moreover, the collar member 22 and the cored bar member 24 are set longer than the axial length of the ring member 14. For this reason, it becomes possible to correct the ring member 14 whole, ie, the bump foil 16, whole easily and reliably.

  Further, the collar member 22 is made of a material having a smaller coefficient of thermal expansion than the ring member 14. Thereby, the thermal expansion of the ring member 14 can be suppressed by the collar member 22 during the heat treatment, and the axial center of the core metal member 24 and the axial center of the ring member 14 can be prevented from shifting. . Therefore, there is an advantage that the molding operation of the bump foil 16 is performed with higher accuracy.

  In addition, since the bump foil 16 is corrected by the thermal expansion of the cored bar member 24 at the maximum temperature during the heat treatment process, only the correction amount at the maximum temperature needs to be considered, and the heat treatment operation is effectively simplified. Is done.

Furthermore, the first lid member 26 and the second lid member 28 are formed with a plurality of first holes 32 and second holes 40 on the same axis. For this reason, at the time of heat processing, the 1st hole part 32 and the 2nd hole part 40 can connect with external air, and it can prevent that the bump foil 16 oxidizes.

  Moreover, the plurality of first holes 32 and the second holes 40 are provided coaxially. Therefore, if a knock pin (not shown) is inserted into any of the first hole portion 32 and the second hole portion 40, a plurality of heat treatment apparatuses 20 can be easily and accurately stacked, and workability is improved. Is planned.

  The first lid member 26 and the second lid member 28 are provided with annular first holding portions 36 and 44 that engage with the inner peripheral surface 22a of the collar member 22, respectively. Thereby, the collar member 22 can be accurately and reliably positioned and held via the first lid member 26 and the second lid member 28.

  At this time, the first lid member 26 is provided with an annular second holding portion 38, and the second holding portion 38 is engaged with the inner peripheral surface 24 a of the core metal member 24 to be engaged with the core metal member 24. Positioning is performed. For this reason, there is an effect that the positioning of the collar member 22 and the cored bar member 24 is performed with high accuracy, and the molding accuracy of the bump foil 16 is further improved.

  Here, the second cover member 28 is not provided with the second holding portion. If the first lid member 26 and the second lid member 28 are respectively provided with the second holding portions 38, the core metal member 24 must be positioned with high accuracy by these, and the second holding portion 38. Machining accuracy is required. Therefore, by providing the second holding portion 38 only on the first lid member 26, the workability and the molding accuracy of the bump foil 16 can be improved with a simple and economical configuration.

  Furthermore, the first lid member 26 and the second lid member 28 are made of a material having a smaller coefficient of thermal expansion than the cored bar member 24. As a result, the positions of the first holding portions 36 and 44 and the second holding portion 38 fluctuate due to the thermal expansion of the first lid member 26 and the second lid member 28, and the positioning accuracy of the core metal member 24 and the collar member 22 is increased. It is possible to reliably avoid the influence.

DESCRIPTION OF SYMBOLS 10 ... Foil type gas bearing 14 ... Ring member 16 ... Bump foil 18 ... Top foil 20 ... Heat processing apparatus 22 ... Color member 24 ... Core metal member 26, 28 ... Cover member 32, 40 ... Hole part 36, 38, 44 ... Holding Part

Claims (8)

A foil type gas bearing heat treatment apparatus for producing a foil type gas bearing disposed on the inner peripheral surface of a cylindrical ring member in the order of a corrugated bump foil and a flat plate top foil,
A cylindrical collar member;
A cored bar member disposed inside the collar member;
With
The inner diameter of the collar member is set larger than the outer diameter of the ring member, and the outer diameter of the cored bar member is set smaller than the inner diameter of the ring member,
The axial length of the collar member and the core member is set to be longer than the axial length of the ring member,
The said metal core member is comprised with the material which has a thermal expansion coefficient larger than the said ring member or the said collar member at least, The heat processing apparatus of the foil type gas bearing characterized by the above-mentioned.   2. The heat treatment apparatus for a foil type gas bearing according to claim 1, wherein the collar member is made of a material having a smaller coefficient of thermal expansion than the ring member.   3. The heat treatment apparatus for a foil type gas bearing according to claim 1, wherein the cored bar member is set to have a smaller heat capacity than the ring member and the collar member. The heat treatment apparatus according to any one of claims 1 to 3, wherein a first lid member and a second lid member are disposed at both axial ends of the collar member,
A heat treatment apparatus for a foil-type gas bearing, wherein the first lid member and the second lid member are formed with holes that communicate with each other in the axial direction. 5. The heat treatment apparatus according to claim 4, wherein at least the first lid member or the second lid member has a first holding portion that holds the collar member from an inner peripheral side,
A second holding part for holding the cored bar from the center side;
A heat treatment apparatus for a foil-type gas bearing, characterized in that The heat treatment apparatus according to claim 5, wherein the first lid member is provided with the first holding part and the second holding part,
The heat treatment apparatus for a foil type gas bearing, wherein only the first holding portion is provided on the second lid member.   The heat treatment apparatus for a foil type gas bearing according to any one of claims 4 to 6, wherein the lid member is made of a material having a smaller coefficient of thermal expansion than the cored bar member. apparatus. A foil type gas bearing heat treatment method for producing a foil type gas bearing disposed on the inner peripheral surface of a cylindrical ring member in the order of a corrugated bump foil and a flat top foil,
In the gap between the cylindrical collar member that is longer than the axial length of the ring member and the core member that is disposed inside the collar member and is longer than the axial length of the ring member, A step of disposing at least the ring member thinner than the gap to which the bump foil is joined;
A step of correcting the bump foil under an expansion action of the cored bar member having at least a thermal expansion coefficient higher than that of the ring member or the collar member by heat treatment;
A step of shrinking the cored bar member in a direction away from the bump foil by performing a cooling process;
A method for heat-treating a foil type gas bearing, comprising:

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