JP3952707B2 - Manufacturing method of bearing and bearing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bearing manufacturing method and a bearing that are cylindrical and use a resin-based sliding member for a sliding portion.
[0002]
[Prior art]
In recent years, engineering plastic materials having a low coefficient of friction and high heat resistance and wear resistance have attracted attention as sliding materials.
[0003]
In particular, thermoplastic bearings such as polytetrafluoroethylene (hereinafter referred to as PTFE) and polyetheretherketone (hereinafter referred to as PEEK) are used for the sliding members of thrust bearings and journal bearings used in large rotating machines such as water turbine generators. Mainly, polymer composite resin materials in which glass fibers, carbon fibers, graphite, molybdenum disulfide, or the like are added to improve mechanical strength, sliding characteristics, wear resistance, and the like have begun to be employed.
[0004]
Thrust bearings and journal bearings of large rotating machines are subject to high loads, so when using such resin-based sliding materials, make sure that a rigid steel back metal is used as a strength member and integrated with the resin material. Used in combination. However, if the adhesion strength between the two is insufficient in this connection, the resin sliding member will peel off during operation and cause a fatal accident. Therefore, the technology for joining the steel strength member and the resin material is important. It becomes a point.
[0005]
As a publicly known technique for dealing with this point, Japanese Patent Application Laid-Open No. 7-71446 discloses that a PTFE material filled with glass fiber is firmly bonded as a sliding member to the inner peripheral surface of a tilting pad that supports a journal bearing. Techniques to do this are disclosed.
[0006]
Specifically, first, the PTFE material is easily and firmly bonded to the flat plate-shaped porous body by bonding, and then the flat plate is bent into a ring shape (cylindrical shape) with the porous body at the outer peripheral side. Form. A metal foil having a low melting point is wound around the outer peripheral surface of the porous body, and the outer peripheral surface is sandwiched between two divided cylindrical base metal (back metal), and the outer peripheral portion is heated by heating means such as an electric heater or a gas burner while rotating the whole. By heating with, the metal foil is melted and bonded to an integral laminate. Thereafter, the laminated body is divided into a plurality of pieces in the circumferential direction, and each is formed as a tilting pad bearing.
[0007]
[Problems to be solved by the invention]
However, the above prior art has the following problems.
[0008]
In the prior art described in the above-mentioned JP-A-7-71446, first, a PTFE material is pressure-bonded to a plate-like porous body and then formed into a ring shape to form an inner peripheral surface of a cylindrical base metal. Discloses a method of stably bonding a laminate by fusion bonding via a metal foil. Here, there are various cases of the resin material used for the sliding member depending on the specifications and performance of the rotating machine (electric motor, pump, etc.) provided with the rotating shaft. When a highly elastic resin material such as a tetrafluoroethylene material is used for the sliding member, a stable coupling can be maintained even if the PTFE material, which is an elastic body, is bent from a plate shape to a ring shape as in the above prior art. However, when a resin material having high hardness such as PEEK is used, it is not easy to bend from a plate shape to a ring shape, and the PEEK bond to the porous body becomes unstable after forming the ring shape. As a result, it becomes difficult to prevent peeling, and it is difficult to improve reliability.
[0009]
An object of the present invention is to provide a bearing manufacturing method and a bearing capable of realizing high bonding strength of a resin-based sliding member and improving reliability.
[0010]
[Means for Solving the Problems]
(1) In order to achieve the above object, according to the present invention, in a method for manufacturing a bearing, which is disposed on the outer peripheral portion of the rotating shaft and is formed by connecting a resin-based sliding member to the sliding side surface of the back metal, On the inner peripheral side of the substantially cylindrical back metal having a circumferentially divided structure, a substantially cylindrical shape of the circumferentially divided structure is a porous body, and a metal filter that is subjected to crushing treatment on the back metal side is disposed with a brazing material interposed therebetween, While being assembled into a substantially cylindrical shape by a jig, they are positioned on the inner peripheral side of the high-frequency heating coil, and heated by the high-frequency heating coil, and pressed in the radial direction by an equal pressure device disposed on the inner peripheral side of the metal filter. Then, after performing the first bonding process for bonding the metal filter to the inner peripheral side of the back metal, after the temperature is raised to a temperature equal to or higher than the melting point of the resin sliding member by the high-frequency heating coil, For the circumferential direction on the inner circumference The resin-type sliding member having a substantially cylindrical structure is arranged, and a second coupling process is performed in which the resin-type sliding member is coupled to the inner peripheral side of the metal filter by applying pressure in the radial direction with the uniform pressure device. Do.
[0011]
In the present invention, a metal filter is interposed between the resin-based sliding member and the back metal for bonding. First, a metal filter is disposed on the inner peripheral side of the back metal via a brazing material, and a first bonding process is performed in which pressure bonding is performed with heating. And the 2nd coupling | bonding process which arrange | positions a resin-type sliding member on the internal peripheral surface of the metal filter used as high temperature, and carries out pressure coupling | bonding is performed.
[0012]
At this time, the heating in the first coupling process and the second coupling process is evenly heated by the high-frequency heating coil, and the pressurization is performed in the radial direction with a uniform distribution in the circumferential direction by the uniform pressurization device. As a result, the brazing material between the back metal and the metal filter and the resin sliding member at the boundary between the metal filter are evenly melted, and the pores of the metal filter are evenly impregnated with the resin sliding member. Therefore, it is possible to improve the reliability of the coupling between the back metal and the resin sliding member.
[0013]
Also, by sufficiently impregnating the metal filter and the resin sliding member by the above uniform heating and equal pressure, the internal air remaining in the pores of the metal filter and the resin sliding member during heating The generated gas is completely discharged to the outside without accumulating at the boundary portion between the metal filter and the resin-based sliding member, and the formation of floating and peeling can be prevented.
[0014]
Therefore, according to the present invention, the high bonding strength of the resin-based sliding member can be realized and the reliability can be improved.
[0017]
(2) In order to achieve the above object, according to the present invention, in a bearing arranged on the outer peripheral portion of the rotating shaft and having a resin-based sliding member coupled to the sliding side surface of the back metal, a circumferentially divided structure On the inner peripheral side of the substantially cylindrical back metal, a substantially cylindrical and porous body with a circumferentially divided structure is disposed, and a metal filter with a crushing treatment on the back metal side is arranged with a brazing material interposed therebetween, and these are substantially omitted with a jig. While being assembled into a cylindrical shape, the metal filter is positioned on the inner peripheral side of the high-frequency heating coil, heated by the high-frequency heating coil, and pressurized in the radial direction by an equal pressure device disposed on the inner peripheral side of the metal filter. After the first bonding process for bonding the inner side of the backing metal to the inner peripheral side of the metal filter, the first high-frequency heating coil raises the temperature to a temperature equal to or higher than the melting point of the resin-based sliding member. Approximate cylinder with direction division structure The resin-based sliding member is disposed, and the second pressure is applied in the radial direction by the uniform pressure device to perform the second bonding process for bonding the resin-based sliding member to the inner peripheral side of the metal filter. .
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A bearing manufacturing method according to an embodiment of the present invention and a journal bearing manufactured by this method will be described below with reference to FIGS.
[0019]
First, FIG. 2 is an axial longitudinal sectional view of a boiler feed pump to which a journal bearing according to the present invention is applied. 101 is a boiler feed pump, and the boiler feed pump 101 is roughly described as a whole of the feed pump 101. A pump casing 102 for storing the water, a water absorbing portion 103 for sucking water into the pump casing 102, an impeller 104 for increasing the pressure of the sucked water, a rotating main shaft 105 coupled with the impeller 104 and rotating together, and an outer peripheral portion of the impeller 104 And a diffuser 106 that guides the discharged water to the next stage impeller 104 and a discharge unit 107 that discharges the pressurized water to the outside of the pump casing 102.
[0020]
Further, both ends of the rotation main shaft 105 are supported by the journal bearing 1, and further, a thrust force generated by an internal pressure difference of the impeller 104 is supported by a thrust bearing 109 disposed at one end portion.
[0021]
FIG. 3 is a longitudinal sectional view in the axial direction of the oil lubricated bearing device 110 that supports the left end portion of the rotary main shaft 105 in FIG. 2. The oil lubricated bearing device 110 is roughly divided into a bearing casing 111 and upper and lower parts. A journal bearing 1 that can be divided into two halved shapes and supports the rotary main shaft 105 in the bearing casing 111, and an oil tank 112 formed so that the lubricating oil 115 can be stored in the bearing casing 111 below the journal bearing 1. And a self-lubricating pump 113 installed around the rotary main shaft 105 in the oil tank 112, and a labyrinth seal 114 that seals the pressure difference between the oil tank 112 and the outside of the oil lubricated bearing device 110.
[0022]
The journal bearing 1 is a cylindrical bearing having a laminated structure in which a metal filter 4 and a resin-based sliding member 5 are coupled to the inner peripheral side of a steel back metal 2 via a brazing material 3, and by a self-lubricating pump 113. Lubricated by forced lubrication.
[0023]
4 is a cross-sectional view of the self-lubricating pump 113 as viewed from the XX plane in FIG. 3. The self-lubricating pump 113 includes a disk 116 coaxially installed on the rotation main shaft, An oil case 117 that is in contact with the lower outer peripheral portion and is held so as to be swingable in a radial direction via an elastic body 124 such as a coil or a disc spring, and is made of a polymer resin and formed in a substantially arc shape; An oil suction pipe 119 installed at the bottom of the oil tank 112 so as to communicate with a later-described suction port 118 formed in 117, and provided so as to communicate from the upper part of the oil tank 112 to the upper part of the journal bearing 1 (see FIG. 3). An introduction hole 120 and a flexible pipe 122 connected to an introduction hole 120 provided in the upper part of the oil tank 112 in communication with a later-described discharge port 121 formed in the oil case 117 are provided.
[0024]
FIG. 5 is an overall perspective view of the oil case 117. The oil case 117 has a shallow groove-shaped oil chamber 123 formed along the circumferential direction on the inner peripheral surface, and the oil chamber 123 has a lower end at the lower end. A penetrating suction port 118 is formed, and an upper end of the oil chamber 123 is formed with a discharge port 121 that communicates with the upper end surface of the oil case 117.
[0025]
Returning to FIG. 4, when the oil supply pump 113 is operated, the disk 116 rotates together with the rotation main shaft 105, and the lubricating oil 115 supplied to the oil chamber 123 through the oil absorption pipe 119 from a separate oil absorption chamber (not shown) is The oil chamber 123 rises along the outer periphery of 116, and at the same time, a pressure P in the radial direction is generated in the lubricating oil 115 by centrifugal force. The lubricating oil 115 that has reached the discharge port 121 at the upper end of the oil chamber 123 is discharged upward by the pressure P and supplied to the journal bearing 1 through the flexible tube 122 and the introduction hole 120.
[0026]
Next, FIG. 6 is a process flowchart of a method for manufacturing the journal bearing 1 by joining the resin-based sliding member 5 to the back metal 2 according to the present invention.
[0027]
In FIG. 6, the manufacturing method of the bearing according to the present invention is roughly described. First, a metal filter 4 is disposed on the inner peripheral surface of the back metal 2 with the brazing material 3 interposed therebetween, and these are heated and pressurized. A first combining process is performed by combining the above. Next, the 2nd coupling | bonding process which arrange | positions the resin-type sliding member 5 to the internal peripheral surface of the metal filter 4, and couple | bonds them by heating and pressurizing operation is performed. As described above, the resin-based sliding member 5 is bonded to the back metal 2 through the bonding process performed twice.
[0028]
FIG. 7 is a front view of a journal bearing manufacturing apparatus used for carrying out the bearing manufacturing method according to the present invention.
[0029]
In FIG. 7, reference numeral 6 denotes a manufacturing apparatus. The manufacturing apparatus 6 can be roughly referred to as a frame body 7 constituting an outer structure of the entire manufacturing apparatus 6, and can be rotated around a vertical axis inside the frame body 7. A table 8 installed so as to be movable up and down, a high-frequency heating coil 9 coaxial with the table 8 and arranged so as to surround the outer periphery thereof, and a jig 12 installed on the inner periphery of the high-frequency heating coil 9 on the table 8 A hydraulic press machine 10 installed at an upper extension position of the rotary shaft of the table 8 and a uniform pressure device 11 that can be moved up and down by the hydraulic press machine 10 on the same axis are provided.
[0030]
FIG. 1 is a perspective view of a state in which the journal bearing 1 is installed in the main part of the manufacturing apparatus 6 and the second coupling process is performed. Note that the front half of the high-frequency heating coil 9 is omitted to avoid the complexity of the illustration.
[0031]
In FIG. 1, the entire journal bearing 1 constituted by coaxially arranging a back metal 2, a brazing filler metal 3, a metal filter 4, and a resin sliding member 5 in order from the outer peripheral side is divided into two in the circumferential direction. It has a split structure. This halved structure is for enabling the rotary main shaft 105 supported by the journal bearing 1 to be easily removed or assembled during maintenance.
[0032]
Further, as shown in FIG. 8, the metal filter 4 is a thin semi-cylindrical body whose main body is made of a metal porous body, and the outer peripheral surface (the surface facing the back metal 2) 4a is previously crushed. As a result, a substantially flat surface state in which the pores on the surface are filled is obtained. For details of the crushing treatment, when the metal filter 4 is molded, a powder layer having a large particle diameter and a powder layer having a small particle diameter are separately provided in the mold and heated, or the metal filter 4 is formed into a plate shape. After molding, the surface to be crushed is subjected to crushing treatment by means of machining methods such as grinding or milling.
[0033]
The brazing filler metal 3 has a melting point higher than that of the resin-based sliding member 5 and has a good fusion property with a metal.
[0034]
Returning to FIG. 1, a cylindrical jig 12 is coaxially installed on the table 8, and the entire journal bearing 1 having a two-part structure is accommodated and fixed therein. The high frequency heating coil 9 is disposed so as to coaxially surround the outer peripheral side of the jig 12.
[0035]
Further, in FIG. 1, a uniform pressurizing device 11 installed at a lower position than a hydraulic press 10 (not shown) installed above is positioned on the inner peripheral side of the resin-based sliding member 5.
[0036]
FIG. 9 is a perspective view of the main part of the uniform pressure device 11. In this figure, an equal pressure device 11 includes a main shaft 13 connected to be movable up and down by a hydraulic press 10, three arms 14 that can be pivoted up and down on the outer periphery of the main shaft 13, And a collar 15 attached to the tip of the arm 14.
[0037]
The uniform pressure device 11 configured as described above is operated by a toggle mechanism. That is, as shown in the figure, the connecting point 16 of each collar 15 and each arm 14 is lower than the connecting point 17 of the main shaft 13 and each arm 14, and the outer peripheral surface of each collar 15 is the same cylindrical inner peripheral surface. If the load is applied to the main shaft 13 downward in the axial direction in this state, it is converted into a radial load by each collar 15 through the rotation of each arm 14. Each collar 15 operates so as to radially press the contacting inner peripheral surface with a uniform distribution in the circumferential direction. Further, in order to couple the journal bearings 1 having different sizes, a uniform pressure device in which the length and number of the arms 14 are appropriately changed may be used.
[0038]
The process of the bearing manufacturing method shown in FIG. 6 will be described using the bearing manufacturing apparatus having the above configuration.
[0039]
First, the first joining process for joining the back metal 2 and the metal filter 4 will be described. A back metal is disposed on the inner periphery of the cylindrical jig 12, and the brazing material 3 and the metal filter 4 are disposed in close contact with the inner peripheral surface in this order. Each of the members constituting the journal bearing 1 has a halved structure, and the joints are arranged so as to coincide with each other. Subsequently, the uniform pressure device 11 is positioned on the inner peripheral side of the innermost metal filter 4, and each collar 15 is brought into contact with the inner peripheral surface of the metal filter 4.
[0040]
From this state, the high frequency heating coil 9 is operated to start heating. At this time, the entire journal bearing 1 can be heated evenly by rotating the table 8 or repeatedly moving it up and down. The brazing filler metal 3 melted by this heating is fused to the surface of the metal filter 4 without intruding into the pores of the metal filter 4 main body by coming into contact with the crushed surface 4a.
[0041]
Further, along with this heating, the inner peripheral surface of the metal filter 4 is evenly pressurized by applying a downward load to the main shaft of the uniform pressure device 11 by the hydraulic press machine 10. By performing uniform pressurization in such a circumferential direction, it is possible to evenly bond tightly without forming a cavity due to floating or peeling between the inner peripheral surface of the back metal 2 and the outer peripheral surface 4a of the metal filter 4. it can. Here, if the applied pressure is too large, the molten brazing material 3 is pushed out from between the back metal 2 and the metal filter 4 and flows down to the lower portion, so that the bonding force is impaired. The magnitude of the load needs to be adjusted appropriately.
[0042]
Next, the second joining process for joining the metal filter 4 and the resin-based sliding member 5 will be described. First, after confirming that the surface temperature of the joined body of the back metal 2 and the metal filter 4 has been raised to the melting point of the resin sliding member 5 by the first bonding treatment, the resin sliding member 5 having a halved structure is made of metal. The seam is arranged so as to coincide with the inner peripheral surface of the filter 4, and the uniform pressurizing device 11 is installed on the inner peripheral side of the resin-based sliding member 5 as in the first bonding process (see FIG. 1).
[0043]
At this time, since the surface temperature of the metal filter 4 exceeds the melting point of the resin-based sliding member 5, the outer peripheral surface of the resin-based sliding member 5 in contact with the inner peripheral surface of the metal filter 4 is melted. From this state, a high load is applied to the uniform pressurization device 11 by the hydraulic press machine 10 and the internal peripheral surface of the resin slide member 5 is evenly pressurized, thereby causing the resin slide at the contact boundary with the metal filter 4. The molten part of the moving member 5 is impregnated into the pores of the metal filter 4. This impregnation press is sufficiently performed until a part of the resin sliding member 5 impregnated in the metal filter 4 is pushed out.
[0044]
The bond strength between the metal filter 4 and the resin-based sliding member 5 and the reliability due to such impregnation are the anchor effect of the resin impregnated in the pores of the metal filter 4, that is, the resin bites into the pores and spreads inside. It is dominated by the form-fixing action.
[0045]
Further, when the impregnation pressurization is performed, the resin-based sliding member 5 can be further melted by further heating with the high-frequency heating coil 9, and at that time, the journal bearing 1 together with the table 8 is rotated or moved up and down. By moving it, the entire journal bearing 1 can be heated uniformly to eliminate uneven heating, and the reliability of the coupling between the metal filter 4 and the resin-based sliding member 5 can be improved.
[0046]
Therefore, in the second bonding process, the metal filter 4 and the resin-based sliding member 5 are sufficiently impregnated by uniform heating and uniform pressure, so that not only high bonding strength due to the anchor effect can be obtained, but also metal Internal air remaining in the pores of the filter 4 or gas generated from the resin sliding member 5 during heating does not collect outside at the boundary between the metal filter 4 and the resin sliding member 5. Since it is completely released, it is possible to prevent the formation of floating and peeling.
[0047]
As described above, according to the bearing manufacturing method according to the present invention, high bonding strength of the resin-based sliding member can be realized and reliability can be improved by performing the first bonding process and the second bonding process.
[0048]
The rotary machine to which the journal bearing 1 manufactured according to the present invention can be applied is not limited to the above-described horizontal axis boiler feed pump, and can also be applied to, for example, a vertical axis pump, an electric motor, and a speed increaser.
[0049]
In the journal bearing 1 manufactured according to the present invention, carbon fiber, graphite, bronze, glass fiber, and fluorine compound are used as the material of the resin-based sliding member 5 that forms the sliding surface of the journal bearing 1 depending on the purpose. It is preferable to use thermoplastic compositions added as appropriate, and these have better wear resistance and lower wear coefficient than white metal, so that a stable fluid lubrication action can be obtained even under high surface pressure conditions. . Also, while the melting point of white metal is around 240 ° C, in the case of the above-mentioned resin materials, there are materials that are about 100 ° C higher than that, and it has excellent high-temperature fatigue strength, so it can be operated during startup and shutdown. There is an advantage in that the sliding surface is not damaged even if it is operated for a long time in a state where the oil film is not sufficiently formed on the sliding surface in the state.
[0050]
【The invention's effect】
According to the present invention, the first bonding process in which the metal filter is heated and pressure bonded to the inner peripheral side of the back metal via the brazing material, and the resin-based sliding member is heated on the inner peripheral side of the back metal / metal filter combined body. When performing the second coupling process for pressure coupling, the entire bearing is heated evenly by the high-frequency heating coil while being rotated, and the radial pressure is evenly distributed in the circumferential direction by the uniform pressure device. As a result, the brazing material between the back metal and the metal filter and the resin sliding member at the boundary between the metal filter are evenly melted, and the resin sliding member is uniformly impregnated in the pores of the metal filter. Therefore, high bonding strength of the resin-based sliding member can be realized, and the reliability can be improved.
[Brief description of the drawings]
FIG. 1 is a perspective view of a main part of a manufacturing apparatus in a state where a journal bearing is installed and a second coupling process is performed.
FIG. 2 is an axial longitudinal sectional view of a boiler feed pump to which a journal bearing according to the present invention is applied.
FIG. 3 is an axial longitudinal sectional view of an oil lubricated bearing device for supporting a left end portion of a rotating main shaft.
4 is a cross-sectional view of the self-lubricating pump as viewed from the XX plane in FIG. 3;
FIG. 5 is an overall perspective view of an oil case.
FIG. 6 is a process flowchart of a method for manufacturing a journal bearing by bonding a resin-based sliding member to a back metal according to the present invention.
FIG. 7 is a front view of a journal bearing manufacturing apparatus used for carrying out the bearing manufacturing method according to the present invention.
FIG. 8 is a perspective view of a metal filter.
FIG. 9 is a perspective view of a main part of the uniform pressure device.
[Explanation of symbols]
1 Journal bearing (bearing)
2 Back metal 3 Brazing material 4 Metal filter 4a Crushed surface 5 Resin sliding member 6 Manufacturing device 8 Table 9 High frequency heating coil 10 Hydraulic press 11 Uniform pressure device 12 Jig 13 Main shaft 14 Arm 15 Color 105 Rotating main shaft ( Axis of rotation)

Claims (2)

In a method for manufacturing a bearing that is disposed on the outer peripheral portion of the rotating shaft and is formed by connecting a resin-based sliding member to the sliding side surface of the back metal, a circumferentially divided structure is provided on the inner peripheral side of the substantially cylindrical back metal. It is a substantially cylindrical and porous body with a direction division structure, and a metal filter that has been crushed on the back metal side is placed with a brazing material in between, and assembled into a substantially cylindrical shape with a jig on the inner peripheral side of the high-frequency heating coil A first coupling that is positioned and heated by the high-frequency heating coil while being radially pressurized by an equal pressure device disposed on the inner peripheral side of the metal filter to couple the metal filter to the inner peripheral side of the backing metal After the treatment, after the temperature is raised to a temperature equal to or higher than the melting point of the resin-based sliding member by the high-frequency heating coil, the substantially cylindrical resin-based sliding having a circumferentially divided structure on the inner peripheral side of the metal filter Place the member Method for producing a bearing which is characterized in that the second coupling process radially pressurized coupling the resin-based sliding member on the inner peripheral side of the metal filter by an equal pressure device. In a bearing arranged on the outer peripheral portion of the rotating shaft and having a resin-based sliding member coupled to the sliding side surface of the back metal, on the inner peripheral side of the substantially cylindrical back metal of the circumferential direction divided structure, It is a substantially cylindrical and porous body, and a metal filter that has been subjected to crushing treatment on the back metal side is disposed with a brazing material interposed therebetween, and these are positioned on the inner peripheral side of the high-frequency heating coil while being assembled into a substantially cylindrical shape by a jig, While being heated by a high-frequency heating coil, a first bonding process was performed in which the metal filter was bonded to the inner peripheral side of the back metal by pressing in the radial direction with an equal pressure device disposed on the inner peripheral side of the metal filter. Then, after the temperature is raised to a temperature equal to or higher than the melting point of the resin-based sliding member by the high-frequency heating coil, a substantially cylindrical resin-based sliding member having a circumferentially divided structure is disposed on the inner peripheral side of the metal filter, According to the uniform pressure device Bearings, characterized in that the radially pressurizing is produced by performing a second binding process of binding the resin-based sliding member on the inner peripheral side of the metal filter.

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