JP2018173169A - Slide member for high temperature application - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide member for high temperature applications, capable of exhibiting excellent slide performance even under a high temperature condition of 400°C or more and a condition in which a high load acts.SOLUTION: A slide member 1A is configured to hold an expansion graphite layer 2 between a first metal plate 3 and a second metal plate 4 in a state that a plurality of holds 3a, 4a formed on the respective metal plates 3, 4 are filled with surface portions 2a, 2b of the expansion graphite layer 2. A position in a surface direction of each hole 3a formed on the first metal plate 3 is not consistent with a position in the surface direction of each hole 4a formed on the second metal plate 4. The slide member 1A is, for example, used as a radial bearing bent into a cylindrical shape, or as a thrust bearing punched into an annular plate shape.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sliding member for high temperature that can be used as a bearing for bearing a rotating shaft or a reciprocating shaft of various fluid devices such as a stem such as a ball valve, a butterfly valve, a gate valve, and a globe valve that handle a high temperature fluid. It is about.

  As a general sliding member, a metal, a resin such as polytetrafluoroethylene (PTFE) or carbon, or a combination thereof, is well known, but a sliding surface made of metal has a sliding resistance. High sliding surfaces made of a resin such as PTFE cannot be used in a high temperature range, and sliding surfaces made of carbon must be used under conditions where a high load is applied (for example, the valve stem is subject to fluid pressure). There is a risk of breakage (breaking) under the condition of being strongly pressed against the sliding member.

  Therefore, conventionally, as disclosed in FIG. 5 or FIG. 6 of Patent Document 1, an expanded graphite layer is used as a punching metal or the like as a high temperature sliding member that solves the problem of such a general sliding member. There have been proposed ones reinforced with a wire mesh (FIG. 5) and those having a back metal fixed to the expanded graphite layer with an adhesive (FIG. 6). Thus, the sliding member for high temperature whose sliding surface is made of expanded graphite is superior in sliding performance compared to the sliding surface made of metal, compared to the sliding surface made of resin. It can be suitably used even under high temperature conditions, and since it is reinforced with a wire mesh or a back metal, it is not damaged even under conditions of high loads.

Japanese Patent Laid-Open No. 10-325471

However, in the sliding member for high temperature disclosed in FIG. 5 of Patent Document 1 (hereinafter referred to as “first conventional sliding member”), the expanded graphite layer is reinforced with a wire mesh, but the strength as the sliding member is high. It is difficult to use because there is a problem in durability under the condition where the load is insufficient and high load is applied. On the other hand, in the high temperature sliding member disclosed in FIG. 6 of Patent Document 1 (hereinafter referred to as “second conventional sliding member”), the expanded graphite layer is reinforced with a back metal, so that a high load is applied. Although it is relatively excellent in durability, the adhesive that fixes the back metal to the expanded graphite layer elutes under high temperature conditions (for example, 400 ° C. or higher), and cannot be used under such high temperature conditions. Furthermore, the first and second conventional sliding members have problems such as the strength of the surface of the expanded graphite layer constituting the sliding surface is low, and the expanded graphite layer is deformed or peeled off by sliding with the counterpart member. It cannot be used satisfactorily under conditions where high loads are applied.

  The present invention has been made in view of such points, and is excellent in durability and can exhibit good sliding performance even under a high temperature condition of 400 ° C. or higher and under a high load. The object is to provide a high-temperature sliding member.

  In order to achieve the above object, the present invention fills the surface portion of the expanded graphite layer into a plurality of holes formed in the first metal plate between the first metal plate and the second metal plate. A high-temperature sliding member is proposed which is characterized by being pinched in a heated state.

  In such a high temperature sliding member, the aperture ratio of the holes formed in the first metal plate (the area ratio of all the holes to the first metal plate) is preferably 10 to 50%, and the first metal plate It is preferable that the hole formed in this is a circular hole and the hole diameter is 0.2-2.5 mm. Moreover, a plurality of holes can be formed in the second metal plate, and both surface portions of the expanded graphite layer can be filled in the holes of both metal plates. In this case, the size and / or opening ratio of the holes formed in the first metal plate is the size and / or opening ratio of the holes formed in the second metal plate (area ratio of all holes to the second metal plate). Is preferably the same. In addition, the size and / or aperture ratio of the holes formed in the first metal plate can be made larger than the size and / or aperture ratio of the holes formed in the second metal plate. When a plurality of holes are formed in the second metal plate, it is preferable that the surface position of each hole formed in the first metal plate does not match the surface direction position of each hole formed in the second metal plate. In addition, when the surface of the second metal plate is made to function as a sliding surface, the aperture ratio of the holes formed in the second metal plate is preferably 10 to 50%, and each hole of the second metal plate Is a circular hole, and the hole diameter is preferably 0.2 to 2.5 mm. Moreover, it is preferable that the surface direction position of each hole formed in the 1st metal plate and the surface direction position of each hole formed in the 2nd metal plate do not correspond. The expanded graphite layer can be made of one expanded graphite sheet, and the expanded graphite layer can be made by laminating a plurality of expanded graphite sheets. These high-temperature sliding members can be used as radial bearings bent into a cylindrical shape or as thrust bearings punched into an annular plate shape.

  In the sliding member for high temperature of the present invention, the sliding surface is constituted by the surface of the first metal plate and a plurality of expanded graphite portions exposed on the surface, so it is good even at a high temperature condition of 400 ° C. or higher. Excellent sliding performance. Moreover, the expanded graphite portion is filled in the hole of the first metal plate and is reinforced by the hole, and the expanded graphite layer is sandwiched between the first metal plate and the second metal plate. The sliding surface and the entire sliding member have high strength, excellent durability, and good sliding performance without causing problems as in the first and second conventional sliding members even under conditions where high loads are applied. Can be demonstrated. In particular, when the expanded graphite layer is formed by laminating a plurality of expanded graphite sheets, sliding occurs further at the contact surface between the expanded graphite sheets, and the sliding performance is further improved.

FIG. 1 is a plan view showing an example of a high-temperature sliding member according to the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a cross-sectional view showing an example in which the high temperature sliding member shown in FIG. 1 is used as a radial bearing. FIG. 4 is a plan view showing a modification of the high temperature sliding member according to the present invention. FIG. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a sectional view showing an example in which the high temperature sliding member shown in FIG. 4 is used as a radial bearing. FIG. 7 is a plan view showing another modification of the high temperature sliding member according to the present invention. FIG. 8 is a sectional view taken along line VIII-VIII in FIG. FIG. 9 is a sectional view showing an example in which the high-temperature sliding member shown in FIG. 7 is used as a radial bearing. FIG. 10 is a plan view showing still another modified example of the high temperature sliding member according to the present invention. 11 is a cross-sectional view taken along line XI-XI in FIG. FIG. 12 is a cross-sectional view showing an example in which the high temperature sliding member shown in FIG. 10 is used as a radial bearing. FIG. 13 is a plan view showing an example in which the high temperature sliding member shown in FIG. 1 is used as a thrust bearing. FIG. 14 is a plan view showing an example in which the high temperature sliding member shown in FIG. 4 is used as a thrust bearing. 15A and 15B are cross-sectional views corresponding to FIG. 2 showing still another modification of the high temperature sliding member according to the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 is a plan view showing an example of a high-temperature sliding member according to the present invention, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 shows the high-temperature sliding member as a radial bearing. It is sectional drawing which shows the example used as.

  A high-temperature sliding member (hereinafter referred to as “first sliding member”) 1 </ b> A shown in FIGS. 1 and 2 includes an expanded graphite layer 2 between the first metal plate 3 and the second metal plate 4. A plurality of holes (through holes) 3a and 4a formed in 3 and 4 are sandwiched and filled with both surface portions 2a and 2b of the expanded graphite layer 2. In this example, the expanded graphite layer 2 is It is composed of a single expanded graphite sheet 2A.

  That is, the first sliding member 1A presses the expanded graphite layer 2 composed of one expanded graphite sheet 2A between the metal plates 3 and 4, thereby pressing both surface portions 2a of the expanded graphite sheet 2A. , 2b is obtained by bulging and filling the holes 3a, 4a of the metal plates 3, 4, respectively. The expanded graphite portions 2a, 2b bulged and filled in the holes 3a, 4a are shown in FIG. 2, the surface of each metal plate 3, 4 is exposed to form the surface of each metal plate 3, 4 as a low friction sliding surface, and the expanded graphite sheet 2 A is bonded to both metal plates 3, 4. Ensuring sufficient strength by anchoring effect.

  The thickness of each of the metal plates 3 and 4 is preferably made as thin as possible on the condition that the strength of the first sliding member 1A can be sufficiently secured. A thin metal plate such as stainless steel having a thickness is used so that the first sliding member 1A can be easily formed by bending or the like. Further, the thickness of the expanded graphite sheet 2A is set so that the both surface portions 2a, 2b of the expanded graphite sheet 2A are bulged and filled in the holes 3a, 4a by pressure molding. The thickness of the expanded graphite sheet 2A is set to be slightly larger than the thickness of the metal plates 3 and 4 in this example.

  Further, the shape, size, arrangement, etc. of each hole 3a, 4a can be appropriately set in consideration of the required strength, sliding performance, etc. In this example, as shown in FIG. 3a and 4a are equally arranged at the same pitch interval as circular holes having the same number and the same diameter. That is, the size and opening ratio of the holes 3 a formed in the first metal plate 3 (the area ratio of all the holes 3 a with respect to the first metal plate 3) and the sizes and openings of the holes 4 a formed in the second metal plate 4. The rate (area ratio of all holes 4a to the second metal plate 4) is the same. Further, the holes 3a formed in the first metal plate 3 and the holes 4a formed in the second metal plate 4 are bent in the surface direction of the metal plates 3 and 4 (the position in the surface direction of each hole 3a) The holes 4a are arranged so that the positions in the surface direction of the holes 4a do not coincide with each other. That is, the holes 3 a and the holes 4 a are arranged so as not to overlap in the thickness direction of the metal plates 3 and 4. The holes 3a of the first metal plate 3 and the holes 4a of the second metal plate 4 are preferably not overlapped in the plane direction, but it is also possible to prevent a part of them from overlapping. .

  4 is a plan view showing a modified example of the high temperature sliding member according to the present invention, FIG. 5 is a sectional view taken along the line V-V in FIG. 1, and FIG. 6 is the high temperature sliding member. It is sectional drawing which shows the example which uses as a radial bearing.

  The high temperature sliding member (hereinafter referred to as “second sliding member”) 1B shown in FIGS. 4 and 5 is located between the first metal plate 3 and the second metal plate 4 in the same manner as the first sliding member 1A. The expanded graphite layer 2 is sandwiched between two expanded graphite layers 2B and 2C. In this example, the expanded graphite layer 2 is divided into two sheets. It is composed of expanded graphite sheets 2B and 2C.

  As shown in FIG. 5, the second sliding member 1 </ b> B includes the expanded graphite layer 2 on both surface portions, that is, the surface portion 2 a of the expanded graphite sheet 2 </ b> B on the first metal plate 3 side and the expanded graphite on the second metal plate 4 side. The sheet 2C is sandwiched between the metal plates 3 and 4 with the surface portion 2b of the sheet 2C filled in the holes 3a of the first metal plate 3 and the holes 4a of the second metal plate 4, respectively.

  That is, the second sliding member 1B pressurizes the expanded graphite layer 2 formed by laminating two expanded graphite sheets 2B and 2C between the first metal plate 3 and the second metal plate 4. Thus, the surface portions 2a and 2b of the expanded graphite sheets 2B and 2C are obtained by bulging and filling the holes 3a and 4a of the metal plates 3 and 4, respectively, and the holes 3a and 4a are expanded. As shown in FIG. 5, the expanded graphite portions 2a and 2b filled and exposed to the surfaces of the metal plates 3 and 4 constitute the surfaces of the metal plates 3 and 4 as low friction sliding surfaces. Adhesive strength between the expanded graphite sheets 2B and 2C and the metal plates 3 and 4 is sufficiently secured by the anchoring effect.

  The thicknesses of the metal plates 3 and 4 are preferably made as thin as possible on condition that the strength of the second sliding member 1B can be sufficiently secured. In this example, the thickness is the same as that of the first sliding member 1A. In addition, the metal plates 3 and 4 are made of a thin metal plate such as stainless steel having the same thickness so that the second sliding member 1B can be easily formed by bending or the like. Further, the thickness of each expanded graphite sheet 2B, 2C is set so that the surface portions 2a, 2b of the expanded graphite sheets 2B, 2C are surely expanded and filled in the holes 3a, 4a by pressure molding. The thickness of each of the expanded graphite sheets 2B and 2C is set to be slightly larger than the thickness of the metal plates 3 and 4 in this example. .

  Further, the shape, size, arrangement, etc. of the holes 3a, 4a can be appropriately set in consideration of the required sliding performance, etc. In this example, similarly to the first sliding member 1A. As shown in FIG. 4, the holes 3a and 4a are equally arranged at the same pitch intervals as circular holes having the same number and the same diameter. That is, similarly to the first sliding member 1 </ b> A, the size and aperture ratio of the holes 3 a formed in the first metal plate 3 (area ratio of all the holes 3 a to the first metal plate 3) and the second metal plate 4 The size and aperture ratio of the formed holes 4a (area ratio of all the holes 4a with respect to the second metal plate 4) are the same. Further, similarly to the first sliding member 1A, each hole 3a formed in the first metal plate 3 and each hole 4a formed in the second metal plate 4 are in the surface direction in the surface direction of the metal plates 3 and 4. It arrange | positions so that it may hesitate (so that the surface direction position of each hole 3a and the surface direction position of each hole 4a may not correspond). That is, the holes 3 a and the holes 4 a are arranged so as not to overlap in the thickness direction of the metal plates 3 and 4. The holes 3a of the first metal plate 3 and the holes 4a of the second metal plate 4 are preferably not overlapped in the plane direction, but it is also possible to prevent a part of them from overlapping. .

  Thus, the first and second sliding members 1A and 1B are bent into a cylindrical shape, for example, as shown in FIGS. 3 and 6, and the stems of ball valves, butterfly valves, gate valves, globe valves, etc. Are used as radial bearings 5A and 5B for supporting a rotating shaft or a reciprocating shaft (hereinafter collectively referred to as an “operation shaft”) in a direction (radial direction) perpendicular to the axis.

  That is, a radial bearing (hereinafter referred to as “first radial bearing”) 5A configured by the first sliding member 1A and a radial bearing (hereinafter referred to as “second radial bearing”) 5B configured by the second sliding member 1B are: As shown in FIGS. 3 and 6, the sliding members 1A and 1B are formed by bending into a cylindrical shape in which the first metal plate 3 is the inner periphery and the second metal plate 4 is the outer periphery. A first metal plate 3 is loaded in a cylindrical bearing space formed between an operating shaft such as a valve stem and a device housing such as a valve case that supports the operating shaft so as to hold the operating shaft in contact.

  According to each of the radial bearings 5A and 5B, the expanded graphite portion 2a filled in each hole 3a of the first metal plate 3 and exposed on the surface of the first metal plate 3 has excellent sliding characteristics. By contacting the expanded graphite portion 2a with the outer peripheral surface of the operating shaft, the contact resistance (friction resistance) with the operating shaft, that is, the sliding resistance of the operating shaft (sliding torque on the rotating shaft) can be greatly reduced. The rotation of the shaft or the reciprocating motion of the reciprocating shaft can be performed smoothly.

  The radial bearings 5A and 5B are formed by sandwiching the expanded graphite layer 2 excellent in heat resistance between the metal plates 3 and 4 with the sliding members 1A and 1B constituting the radial bearings 5A and 5B. It can be suitably used even under high-temperature conditions (for example, 400 ° C. or higher) that cannot be applied with materials or adhesives.

  Further, the first or second radial bearing 5A, 5B is subjected to an axial load (radial load) in which the operating shaft such as the stem of the valve presses the inner peripheral surface (the surface of the first metal plate 3) (fluid). Depending on the pressure or the like, a large axial load may act), but in each of the radial bearings 5A and 5B, the sliding members 1A and 1B constituting the radial bearings 5A and 5B cover both surfaces of the expanded graphite sheet 2A or the expanded graphite sheet groups 2B and 2C. Since it has a multi-layer structure sandwiched between the metal plates 3 and 4, it has a large proof strength against such axial loads, that is, the proof loads of the radial bearings 5A and 5B are large. In addition, when a compressive force in the radial direction (the thickness direction of the metal plates 3 and 4) acts on the radial bearings 5 </ b> A and 5 </ b> B due to the axial load, the expanded graphite portion 2 a protrudes from the hole 3 a of the first metal plate 3. Therefore, even when an axial load is applied to the operating shaft, the sliding resistance of the operating shaft can be reduced. Therefore, the bearing function of the radial bearings 5A and 5B can be satisfactorily exhibited even under high load conditions in which a large axial load acts on the operating shaft. In particular, if the holes 3a formed in the first metal plate 3 and the holes 4a formed in the second metal plate 4 are arranged so as to be bent in the surface direction of the metal plates 3 and 4, the first metal For the expanded graphite portion 3a filled in each hole 3a of the plate 3, the second metal plate 4 is used. For the expanded graphite portion 4a filled in each hole 4a of the second metal plate 4, the first metal plate 3 is used. Each of the axial loads will receive a compressive force acting in the radial direction of the radial bearings 5A and 5B, and the contact between the mating member (the operating shaft and the equipment housing) and the expanded graphite portions 2a and 2b can be satisfactorily performed. The bearing function can be further improved.

  By the way, there is a case where the operating shaft does not uniformly contact the entire inner peripheral surface of the radial bearings 5A and 5B due to the axial load acting on the operating shaft, but may be in a state of being in strong contact with a part (one-contact state). However, in this case, the sliding function of the working shaft and the first metal plate 3 which is the inner peripheral portion of the radial bearing 5A, 5B is not smoothly performed, and the sliding function of the working shaft is increased. There is a risk of lowering. However, even in such a case, as shown in FIG. 2 or 5, the expanded graphite portion 2 b is also formed in each hole 4 a of the second metal plate 4, as shown in FIG. 2 or 5. As filled, the back surfaces of the sliding members 1A and 1B, that is, the outer peripheral surfaces of the radial bearings 5A and 5B, function similarly to the inner peripheral surface as a sliding surface having excellent slidability by the expanded graphite portion 2b. Since it is configured, the expanded graphite portion 2b filled in each hole 4a of the second metal plate 4 slips on the contact surface between the second metal plate 4 and the equipment housing, which is the outer peripheral portion of the radial bearings 5A and 5B. Thus, an increase in the sliding resistance of the operating shaft can be avoided, and the bearing function by the radial bearings 5A and 5B can be satisfactorily exhibited. As described above, the first and second sliding members 1A and 1B are formed by forming the same number of holes 3a and 4a having the same diameter on the metal plates 3 and 4 and having the same sliding characteristics on both surfaces. Therefore, in the case where the radial bearings 5A and 5B are configured, contrary to the above, the second metal plate 4 may be bent into a cylindrical shape with the inner periphery and the first metal plate 3 with the outer periphery.

  Further, since the expanded graphite portions 2a and 2b are filled in the holes 3a and 4a of the metal plates 3 and 4 and are firmly held by the metal plates 3 and 4, the expanded graphite portions 2a and 2b are the counterpart members. Is not easily peeled off from the expanded graphite sheets 2A, 2B, 2C. Therefore, the surface (contact surface) of the expanded graphite layer by sliding with the mating member, like the first or second conventional sliding member where the expanded graphite layer is in full contact with the mating member (operation shaft or equipment housing). As a result, the durability of the sliding members 1A and 1B and the life of the bearing performance are greatly improved.

  Further, in the second radial bearing 5B, as shown in FIG. 6, a plurality (two in the above example) of expanded graphite sheets 2B and 2C are laminated between the metal plates 3 and 4, and the expanded graphite sheet 2B. , 2C contact surfaces (overlapping surfaces) also slip, but the sliding performance due to this slip is the contact surface with the mating member (the contact surface between the operating shaft and the first metal plate 3, the equipment housing and the first housing). This is superior to the sliding performance on the inner and outer peripheral surfaces of the radial bearings 5A and 5B in which a part of the contact surface with the two metal plates 4 is expanded graphite portions 2a and 2b. Therefore, according to the 2nd radial bearing 5B, the sliding performance superior to the 1st radial bearing 5A can be exhibited, and the sliding resistance can further be reduced.

  7 is a plan view showing another modified example of the high temperature sliding member according to the present invention, FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 7, and FIG. It is sectional drawing which shows the example which uses a moving member as a radial bearing.

  A sliding member for high temperature (hereinafter referred to as “third sliding member”) 1C shown in FIGS. 7 and 8 has the size (hole diameter) and opening ratio of the hole 3a of the first metal plate 3 and the opening ratio of the second metal plate 4. Except for the size (hole diameter) and opening ratio of the hole 4a, the first sliding member 1A has the same structure as the first sliding member 1A. The expanded graphite portion 2a exposed from the hole 3a has a large area amount. Although the surface of the metal plate 3 functions as a sliding surface, the surface of the second metal plate 3 having a small area amount of the expanded graphite portion 2b exposed from the hole 4a slides on the same level as the surface of the first metal plate 3. It is used for an application that does not need to have characteristics or an application that does not require the surface of the second metal plate 3 to function as a sliding surface.

  10 is a plan view showing still another modified example of the high temperature sliding member according to the present invention, FIG. 11 is a sectional view taken along the line XI-XI in FIG. 10, and FIG. It is sectional drawing which shows the example which uses a sliding member as a radial bearing.

  The high temperature sliding member (hereinafter referred to as “fourth sliding member”) 1D shown in FIGS. 10 and 11 has the size (hole diameter) and the opening ratio of the hole 3a formed in the first metal plate 3 as the second metal. Except for the size (hole diameter) and the aperture ratio of the hole 4a formed in the plate 4, it has the same structure as the second sliding member 1B, and like the third sliding member 1C, The surface of the first metal plate 3 functions as a sliding surface, but the surface of the second metal plate 3 does not need to have the same sliding characteristics as the surface of the first metal plate 3 or the second metal plate 3 is used for applications that do not require the surface of 3 to function as a sliding surface.

  The third and fourth sliding members 1C, 1D are bent into a cylindrical shape, for example, like the first radial bearing 5A or the second radial bearing 5B, and are made of ball valves, butterfly valves, gate valves, globe valves. It is used as radial bearings 5C and 5D that support an operating shaft such as a stem in a direction (radial direction) perpendicular to the axis.

  That is, a radial bearing (hereinafter referred to as “third radial bearing”) 5C configured by the third sliding member 1C and a radial bearing (hereinafter referred to as “fourth radial bearing”) 5D configured by the fourth sliding member 1D are: As shown in FIGS. 9 and 12, the sliding members 1C and 1D are arranged so that the first metal plate 3 is the inner periphery and the second metal plate 4 is the outer periphery, like the first and second radial bearings 5A and 5B. The first metal plate 3 is formed in a cylindrical bearing space formed between an operating shaft such as the valve stem and a device housing such as a valve case that supports the operating shaft. Is loaded with the operating shaft in contact with the shaft.

  The sliding members 1C and 1D and the radial bearings 5C and 5D are configured with respect to each of the sliding members 1A and 1B and the radial bearings except for the size relationship of the holes 3a and 4a. Since it is the same as bearing 5A, 5B, the detailed description is abbreviate | omitted by using the same code | symbol as FIGS. 1-6 in FIGS.

  Thus, in the third and fourth radial bearings 5C and 5D, each hole 3a of the first metal plate 3 is larger than each hole 4a of the second metal plate 4, and expansion on the surface of the first metal plate 3 is performed. Since the exposed amount (exposed area) of the graphite portion 2a is larger than the exposed amount (exposed area) of the expanded graphite portion 2b on the surface of the second metal plate 4, the first metal plate 3 in contact with the operating shaft is exposed. The sliding characteristics of the surface (the inner peripheral surfaces of the radial bearings 5C and 5D) are superior to the sliding characteristics of the surface of the second metal plate 4 (the outer peripheral surfaces of the radial bearings 5C and 5D) that do not contact the operating shaft. Yes. Therefore, according to each of the radial bearings 5C and 5D, when the inner peripheral surface thereof contacts the outer peripheral surface of the operating shaft, the contact resistance (friction resistance) with the operating shaft, that is, the sliding resistance of the operating shaft (in the rotating shaft). (Sliding torque) can be greatly reduced, and the rotation of the rotating shaft or the reciprocating motion of the reciprocating shaft can be performed smoothly.

  The third and fourth radial bearings 5C and 5D are also preferably used under high temperature conditions (for example, 400 ° C. or higher) that cannot be applied by using a resin sliding material or using an adhesive. For example, the same effects as the effects of the first and second radial bearings 5A and 5B described above can be obtained, and the following effects can be achieved.

  That is, as described above, the third or fourth radial bearing 5C, 5D has an axial load (radial load) in which the operating shaft such as a valve stem presses the inner peripheral surface (the surface of the first metal plate 3). The third and fourth radial bearings 5C and 5D operate in the same manner as the first and second radial bearings 5A and 5B. , 1D is different from the first and second radial bearings 5A, 5B in addition to a multi-layer structure in which both surfaces of the expanded graphite sheet 2A or the expanded graphite sheet groups 2B, 2C are sandwiched between the metal plates 3, 4. Thus, the hole 4 a of the second metal plate 4 that receives the above-described axial load (radial load in which the operating shaft presses the surface of the first metal plate 3) through the expanded graphite layer 2 is more than the hole 3 a of the first metal plate 3. Small, the second Since the strength of the metal plate 4 is higher than the strength of the first metal plate 3, compared to the first and second radial bearings 5 A and 5 B in which the holes 3 a and 4 a having the same hole diameter are formed in both the metal plates 3 and 4. As a result, the strength of the entire radial bearing increases, and the proof strength (load resistance) against the axial load increases. Therefore, according to the third and fourth radial bearings 5C and 5D, in the same manner as the first and second radial bearings 5A and 5B, the radial bearings 5C and 5D are caused to have radial directions (of the metal plates 3 and 4 by the axial load). When a compressive force in the thickness direction) is applied, the expanded graphite portion 2a bulges out in the direction of jumping out from the hole 3a of the first metal plate 3 and comes into stronger contact with the operating shaft. Combined with the ability to reduce sliding resistance, the bearing function can be extremely excellent even under high load conditions where a large axial load acts on the operating shaft.

  By the way, the sliding torque (sliding resistance) and the load resistance (proof strength against the axial load) in the first to fourth radial bearings 5A, 5B, 5C, 5D are the sizes (hole diameters) of the holes 3a and 4a and the metal plate 3. , 4 varies depending on the aperture ratio (area ratio of all holes 3a, 4a to each metal plate 3, 4), so that the sliding torque and load resistance on the rotating shaft are determined by the following first to fourth experiments. Was measured, and a preferable pore diameter and opening ratio were determined.

  In the first experiment, as shown in Table 1, there were seven types of first radial bearings 5A in which the hole diameters, pitches, and aperture ratios of the holes 3a, 4a of the first and second metal plates 3, 4 were the same. The first radial bearing No. 1 has a different hole diameter, pitch, and aperture ratio. 1-No. 7 and the hole diameter, pitch, and aperture ratio of the holes 3a of the first metal plate 3 are the same as those of the first radial bearing No. 1, no. 2 is a first radial bearing 5A that is the same as the first radial bearing 5A, the hole diameter of the hole 4a of the second metal plate 4 is 0.5 mm, the pitch is 1.0 mm, and the aperture ratio is 23%. No. 8, no. 9 and these first radial bearings No. 9 are manufactured. 1-No. The rotating shaft bearing on the inner peripheral surface 9 (the surface of the first metal plate 3) was rotated 10,000 times under a temperature condition of 500 ° C., and the sliding torque and load resistance were measured. The results were as shown in Table 1.

  Further, in the second experiment, nine kinds of second radial bearings 5B having a structure in which the two expanded graphite sheets 2B and 2C are sandwiched by the metal plates 3 and 4, and as shown in Table 2, 1 and the second metal plates 3 and 4, the hole diameters, pitches, and aperture ratios of the holes 3a and 4a are respectively set to the first radial bearing No. 1-No. No. 2 second radial bearing No. 9 10-No. 18 and these second radial bearings No. 18 were manufactured. 10-No. A rotating shaft supported by 18 inner peripheral surfaces (the surface of the first metal plate 3) was rotated 10,000 times under a temperature condition of 500 ° C., and sliding torque and load resistance were measured. The results were as shown in Table 2.

  In the third experiment, as shown in Table 3, the hole diameter, pitch, and opening ratio of the holes 3a of the first metal plate 3 are set to the first radial bearing No. 1 described above. 4-No. 7 is the same type of third radial bearing 5C, the first radial bearing having a hole diameter 4a of the second metal plate 4 of 0.5 mm, a pitch of 1.0 mm, and an aperture ratio of 23%. No. 19-No. 22 and these third radial bearings No. 22 were manufactured. 19-No. The rotating shaft bearing on the inner peripheral surface 22 (the surface of the first metal plate 3) was rotated 10,000 times under a temperature condition of 500 ° C., and the sliding torque and load resistance were measured. The results were as shown in Table 3.

  Further, in the fourth experiment, four types of fourth radial bearings 5D having a structure in which the two expanded graphite sheets 2B and 2C are sandwiched by the metal plates 3 and 4, and as shown in Table 4, The hole diameters, pitches, and aperture ratios of the holes 3a and 4a of the first and second metal plates 3 and 4 are set in accordance with the third radial bearing No. 3, respectively. 19-No. The fourth radial bearing no. 23-No. 26, and these fourth radial bearings No. 26 were manufactured. 23-No. The rotating shaft bearing on the inner peripheral surface of 26 (the surface of the first metal plate 3) was rotated 10,000 times under a temperature condition of 500 ° C., and the sliding torque and load resistance were measured. The results were as shown in Table 4.

    In addition, the measurement of the sliding torque in the 1st-4th experiment was performed in the state which provided the axial load of 10 MPaG to the rotating shaft.

  As understood from the experimental results in Tables 1 to 4, the first radial bearing No. 1 having a hole diameter of 0.2 to 2.5 mm and an aperture ratio of 10 to 50% of the hole 3a of the first metal plate 3 is obtained. 2-No. 6, no. 9, No. 2 radial bearing no. 11-No. 15, no. 18, No. 3 radial bearing no. 19-No. 21 and 4th radial bearing no. 23-No. No. 25 was satisfactory as a radial bearing in both sliding torque and load resistance. On the other hand, the first radial bearing No. 1 having a hole diameter of the hole 3a of the first metal plate 3 of less than 0.2 mm and an aperture ratio of less than 10%. 1, no. 8 and the second radial bearing no. 10, no. No. 17 was satisfactory in terms of load resistance, but was not satisfactory as a radial bearing in terms of sliding torque. Further, the first radial bearing No. 1 in which the hole diameter of the hole 3a of the first metal plate 3 exceeds 2.5 mm and the opening ratio exceeds 50%. 7, second radial bearing 16, third radial bearing no. Although the 22 and the fourth radial bearings 26 were satisfactory in terms of sliding torque, they were not satisfactory in terms of load resistance as radial bearings.

  From the above points, in order to satisfy both the sliding torque and the load resistance, the first metal plate 3 constituting the sliding surface has a hole diameter of 0.2 to 2.5 mm and an aperture ratio of 10 to 50%. It is considered preferable to form 3a. This also applies to the case where the second metal plate 4 functions as a sliding surface. In such a case, the second metal plate 4 has a hole diameter of 0.2 to 2.5 mm and an aperture ratio of 10 to 50%. It is considered preferable to form the holes 4a. In addition, the first radial bearing no. 1-No. 9 and the third radial bearing no. 19-No. 22 and the second radial bearing no. 10-No. 18 and 4th radial bearing no. 23-No. 26, when the hole diameter and the aperture ratio of the hole 3a of the first metal plate 3 are the same, the second and fourth radial bearings No. 10-No. 18, no. 23-No. 26 has a sliding torque of No. 1 and No. 3 radial bearing no. 1-No. 9, no. 19-No. This is significantly lower than the sliding torque of 22. This is because the second and fourth radial bearing Nos. 10-No. 18, no. 23-No. No. 26 is considered to be caused by sliding on the contact surface between the expanded graphite sheets 2B and 2C.

  Further, as can be understood by comparing the experimental results in Tables 3 and 4 with the experimental results in Tables 1 and 2, the third radial bearing no. 19-No. 22 and 4th radial bearing no. 23-No. 26, the first radial bearing No. 26 has the same hole diameter and aperture ratio of the hole 3a of the first metal plate 3. 4-No. 7 and the second and fourth radial bearings No. 13-No. Better than 16. This is because each third radial bearing no. 19-No. 22 and 4th radial bearing no. 23-No. 26, the hole diameter and opening ratio of the hole 4a of the second metal plate 4 are the same as those of the first radial bearing No. 4-No. 7 and the second radial bearing no. 13-No. 16 is smaller than the hole diameter and the opening ratio of the hole 4a of the second metal plate 4, so that the third radial bearing no. 19-No. 22 and 4th radial bearing no. 23-No. 26, the strength of the second metal plate 4 is the first radial bearing no. 4-No. 7 and the second radial bearing no. 13-No. This is considered to be because the strength of the second metal plate 4 in FIG.

By the way, except for the point that the hole diameter of the hole 4a of the second metal plate 4 is set to 0.1 mm, the third radial bearing no. 19-No. No. 3 radial bearing no. 19a, no. 20a, no. 21a, no. The fourth radial bearing No. 4 is the same as the third experiment using 22a, except that the diameter of the hole 4a of the second metal plate 4 is 0.1 mm. 23-No. No. 4 radial bearing no. 23a, no. 24a, no. 25a, no. A sixth experiment identical to the fourth experiment using 26a was performed, and the third radial bearing No. 3 was changed except that the hole diameter of the hole 4a of the second metal plate 4 was 0.2 mm. 19-No. No. 3 radial bearing no. 19b, no. 20b, no. 21b, no. The fourth radial bearing No. 4 is the same as the third experiment using 22b, except that the hole diameter of the hole 4a of the second metal plate 4 is 0.2 mm. 23-No. No. 4 radial bearing no. 23b, no. 24b, no. 25b, no. An eighth experiment identical to the fourth experiment using 26b was performed. And after completion | finish of these experiment, when the adhesion state of the 1st and 2nd metal plates 3 and 4 and the expanded graphite layer 2 was confirmed, the hole diameter of the hole 4a of the 2nd metal plate 4 was set to 0.1 mm. 3 Radial bearing no. 19a-No. 22a and the fourth radial bearing no. 23a-No. In any of 26a, peeling occurred between the second metal plate 4 and the expanded graphite layer 2. This is because the hole 4a of the second metal plate 4 is small, the anchoring effect of the expanded graphite layer 2 by the hole 4a is insufficient, and the adhesive strength between the second metal plate 4 and the expanded graphite layer 2 is insufficient. This is thought to be the cause. On the other hand, the third radial bearing No. 3 in which the hole diameter of the hole 4a of the second metal plate 4 is 0.2 mm. 19b-No. 22b and the fourth radial bearing no. 23b-No. In any case, no peeling occurred between the second metal plate 4 and the expanded graphite layer 2. Therefore, the hole diameter of the second metal plate 4 in the third and fourth radial bearings 5C and 5D is preferably set to 0.2 mm or more on condition that the hole 4a is smaller than the hole 3a of the first metal plate 3. it is conceivable that.

  The first to fourth sliding members 1A, 1B, 1C, and 1D are used as the radial bearings 5A, 5B, 5C, and 5D described above. For example, as shown in FIG. It can also be used as thrust bearings 6A and 6B that support in the direction.

  That is, the thrust bearing 6A shown in FIG. 13 is formed by punching the first sliding member 1A (or the third sliding member 1C) into an annular plate shape, and the thrust bearing 6B shown in FIG. The sliding member 1B (or the fourth sliding member 1D) is punched into an annular plate shape.

  In each thrust bearing 6A, 6B, the first metal plate 3 is in contact with the operating shaft in an annular bearing space formed between the operating shaft such as the valve stem and a device housing such as a valve case for supporting the operating shaft. At the same time, the second metal plate 4 is loaded while being held in the device housing.

  According to the thrust bearings 6A and 6B, the expanded graphite portion 2a filled in each hole 3a of the first metal plate 3 and exposed on the surface of the metal plate 3 has excellent sliding characteristics. The surfaces of the thrust bearings 6A and 6B that are in contact with the surface (the surface of the first metal plate 3) function as a sliding surface with a small sliding resistance, and the operating shaft can be smoothly rotated. The thrust bearings 6A and 6B are subjected to an axial load (thrust load) in which the operating shaft presses the end surface (the surface of the first metal plate 3). The thrust bearings 6A and 6B each have a sliding structure. Since the moving members 1A, 1B, 1C, and 1D have a multi-layer structure in which both surfaces of the expanded graphite sheet 2A or the expanded graphite sheet groups 2B and 2C are sandwiched between the metal plates 3 and 4, resistance to such axial loads is large. That is, the load bearing capacity of the thrust bearings 6A and 6B is large. In particular, the thrust bearings 6A and 6B constituted by the third and fourth sliding members 1C and 1D, in which the hole 4a is smaller than the hole 3a and the strength of the second metal plate 4 is superior to the strength of the first metal plate 3, Compared to the thrust bearings 6A and 6B composed of the first and second sliding members 1A and 1B having the same size of 3a and 4a, the proof stress against the axial load is increased. Therefore, the thrust bearings 6A and 6B can receive the thrust load smoothly and satisfactorily with the equipment housing, and in the same way as the first to fourth radial bearings 5A, 5B, 5C and 5D, Even under (for example, 400 ° C. or higher), a good bearing function can be exhibited. In particular, in the thrust bearing 6B constituted by the second sliding member 1B or the fourth sliding member 1D, since the sliding occurs between the contact surfaces of the expanded graphite sheets 2B and 2C, a better bearing function is provided. It can be demonstrated.

  In addition, the high temperature sliding member of the present invention is not limited to the configuration of the first to fourth sliding members 1A, 1B, 1C, and 1D described above, and is appropriately changed without departing from the basic principle of the present invention. It can be improved.

  For example, the shapes of the holes 3a and 4a formed in the metal plates 3 and 4 are not limited to the circular holes described above, and are arbitrary. For example, in addition to a perfect circle shape, an elliptical shape or a rhombus shape may be used. Further, the interval (pitch) between the holes 3a, 4a does not have to be constant as described above, and can be arbitrarily determined according to the usage form of the first to fourth sliding members 1A, 1B, 1C, 1D.

  Further, in the second sliding member 1B and the fourth sliding member 1D, in the above-described example, the two expanded graphite sheets 2B and 2C are laminated between the metal plates 3 and 4, but the expanded graphite sheet to be laminated. Can be three or more.

  Also, in the first to fourth sliding members 1A, 1B, 1C, 1D, holes 3a, 4a are formed in both metal plates 3, 4, and the expanded graphite portions 2a, 4a are formed in these holes 3a, 4a. In the case of an application in which only one surface (the surface of the first metal plate 3) needs to function as a sliding surface, for example, for high temperature shown in FIG. Like the sliding member 1E or the high temperature sliding member 1F shown in FIG. 5B, the hole 3a may be provided only in the first metal plate 3, and the hole may not be provided in the second metal plate 4. That is, as shown in FIG. 15A, the high temperature sliding member 1E has one expanded graphite between the first metal plate 3 having a plurality of holes 3a and the second metal plate 4 having no holes. The high temperature sliding member 1F is formed by pressing the expanded graphite layer 2 made of the sheet 2A, and the first metal plate 3 having a plurality of holes 3a as shown in FIG. And a second metal plate 4 that does not form holes, and the expanded graphite layer 2 formed by laminating two expanded graphite sheets 2B and 2C is pressed in a pressed state. In this case, in each of the high temperature sliding members 1E and 1F, the back surface of the second metal plate 3 (the contact surface with the expanded graphite sheets 2A and 2C) is shown in FIG. 15A or FIG. As shown in FIG. 4, it can be formed on the rough surface or the uneven surface 4c so as to ensure the adhesive strength between the second metal plate 4 and the expanded graphite sheets 2A and 2C. In the high temperature sliding member 1F shown in FIG. 15 (B), the contact surface between the expanded graphite sheets 2B and 2C is slipped, so that only the first metal plate 3 functions as the sliding surface. The sliding performance is superior to that of the high temperature sliding member 1F shown in FIG.

  Further, the high temperature sliding member of the present invention can be used as a constituent material for bearings other than the radial bearings 5A, 5B, 5C, 5D and the thrust bearings 6A, 6B and various sliding parts. The thickness and shape of the metal plates 3 and 4 can be arbitrarily changed according to the usage form or processing form.

1A First sliding member (high temperature sliding member)
1B Second sliding member (high temperature sliding member)
1C 3rd sliding member (sliding member for high temperature)
1D 4th sliding member (sliding member for high temperature)
2 expanded graphite layer 2A expanded graphite sheet 2B expanded graphite sheet 2C expanded graphite sheet 2a expanded graphite portion 2b expanded graphite portion 3 first metal plate 3a hole 4 second metal plate 4a hole 5A radial bearing 5B radial bearing 5C radial bearing 5D radial bearing 6A Thrust bearing 6B Thrust bearing

Claims (13)

  The expanded graphite layer is sandwiched between a first metal plate and a second metal plate with a plurality of holes formed in the first metal plate filled with a surface portion of the expanded graphite layer. High temperature sliding member.   2. The high temperature sliding member according to claim 1, wherein a plurality of holes are formed in the second metal plate, and both surface portions of the expanded graphite layer are filled in the respective holes of the two metal plates.   The size and / or aperture ratio of the hole formed in the first metal plate is the same as the size and / or aperture ratio of the hole formed in the second metal plate. High temperature sliding member.   3. The high temperature according to claim 2, wherein the size and / or aperture ratio of the holes formed in the first metal plate is larger than the size and / or aperture ratio of the holes formed in the second metal plate. Sliding member.   5. The surface direction position of each hole formed in the first metal plate and the surface direction position of each hole formed in the second metal plate do not coincide with each other. High temperature sliding member.   The sliding member for high temperature according to any one of claims 1 to 5, wherein an opening ratio of holes formed in the first metal plate is 10 to 50%.   The high temperature sliding member according to any one of claims 1 to 6, wherein the hole formed in the first metal plate is a circular hole, and the hole diameter is 0.2 to 2.5 mm.   In the case where the surface of the second metal plate is caused to function as a sliding surface, the aperture ratio of the holes formed in the second metal plate is set to 10 to 50%. High temperature sliding member to be described.   In the case where the surface of the second metal plate functions as a sliding surface, the hole formed in the second metal plate is a circular hole, and the hole diameter is 0.2 to 2.5 mm. Item 9. The high temperature sliding member according to any one of Items 2 to 8.   The high-temperature sliding member according to any one of claims 1 to 9, wherein the expanded graphite layer is composed of one expanded graphite sheet.   The high-temperature sliding member according to any one of claims 1 to 9, wherein the expanded graphite layer is formed by laminating a plurality of expanded graphite sheets.   The high temperature sliding member according to any one of claims 1 to 11, wherein the sliding member is used as a radial bearing bent into a cylindrical shape.   The high temperature sliding member according to any one of claims 1 to 11, wherein the sliding member is used as a thrust bearing punched into an annular plate shape.

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