JP2009257590A - Water-lubrication segment type bearing device and water turbine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-lubrication segment type bearing device for elastic press-contact structure which includes a plurality of bearings, segmented along a circumferential direction of a rotation shaft, with the respective bearings elastically press-contacted with a sleeve mounted on the rotation shaft, and to reduce the cost and improve the handling efficiency, by effectively utilizing advantage of the elastic press-contact structure and advantage of water lubrication. <P>SOLUTION: This water-lubrication segment type bearing device includes the sleeve 2 mounted on the rotating shaft 1; a bearing case 3 disposed in an outer periphery of the sleeve; a plurality of bearings 4, segmented and disposed in sliding contact with the sleeve along a circumferential direction between the sleeve and the bearing case; and an elastically pressing mechanism P for elastically pressing the sliding contact surfaces 4f of the bearings to the sliding contact 2f of the sleeve. The sliding contact surfaces of the bearings are formed out of a resin part 8, and polyphenylene sulfide resin or fluorinated resin is used as the resin material of the resin part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a segment type bearing device having a structure in which a plurality of bearings are arranged by segmenting so as to be in sliding contact with a sleeve fixed to the rotating shaft, for example, a bearing device suitable for supporting the rotating shaft of a water turbine. In particular, the present invention relates to a water-lubricated segment type bearing device in which water is used for lubrication of a sliding contact surface between a sleeve and a bearing, and a water turbine using the same.

  In a water turbine, a water-lubricated bearing device in which a sliding contact surface is formed of a resin material or a ceramic material and uses a lubricant as water is often used as a bearing device for supporting the rotating shaft. An example disclosed in Patent Document 1 is known for such a water-lubricated bearing device. In the water-lubricated bearing device of Patent Document 1, a sleeve fixedly mounted on a rotating shaft for sliding bearing support is formed of a cemented carbide alloy having corrosion resistance, and formed of a thermoplastic resin material on a sliding surface of the bearing. The resin part is provided. This water-lubricated bearing device has the following advantages. In other words, even when a water film breaks locally in a high load region, the plastic portion of the sliding surface, specifically, the resin portion of the polyether ether ketone resin is softened, and plastic flow easily occurs. It becomes smooth and finishes the plastic flow and stabilizes in a familiar state. Since the resin portion easily plastically flows at the local contact portion, the cemented carbide sleeve is not damaged. Since the thermoplastic resin in the resin portion does not swell, the bearing gap can be reduced from the beginning, so that high load resistance can be obtained. Since the cemented carbide has corrosion resistance, the shape of the sliding surface is stable with little change over time. High load resistance is secured for long-term use, and stable bearing performance is obtained.

  As a water-lubricated bearing device for a water turbine, a water-lubricated water turbine main bearing disclosed in Patent Document 2 is known. The water-lubricated water turbine main bearing of Patent Document 2 has a structure in which a journal portion of a main shaft of a water turbine is supported by a pad (bearing metal) that is dividedly arranged, and on the back surface of the pad, the area is 40% or more of the pad back surface area, An elastic body having a thickness of 0.02 to 0.2 times the bearing diameter is disposed. By adopting such a configuration, even if the lubricant is water, the elastic body has a centering ability equivalent to that of the metal pad, and the pad is tilted freely so that it has a proper wedge shape between the main shaft and the spindle. Since a water film is formed, wear and seizure can be prevented.

  As a water-lubricated bearing device for a water turbine, a water-lubricated ceramic bearing device that uses river water as a lubricant is disclosed in Patent Document 3, and a water-lubricated pad type ceramic bearing device that also uses river water as a lubricant is patented. It is disclosed in Document 4. The water-lubricated ceramic bearing device of Patent Document 3 includes a sleeve that is fixed to a rotary shaft and has a cemented carbide portion on the outer peripheral surface, a bearing case that is disposed at the outer peripheral position of the sleeve, and a gap between the bearing case and the sleeve. A plurality of bearings arranged along the circumferential direction, each provided with a ceramic portion on the sliding contact surface with the sleeve, and a bearing having a protruding portion protruding in a spherical shape toward the inner peripheral surface portion of the bearing case on the outer peripheral portion; Each of the bearings is biased in the centripetal direction, and has a structure having elastic means for bringing the ceramic portion of each bearing into contact with the cemented carbide portion of the sleeve when the rotary shaft is stopped. The water-lubricated ceramic bearing device of Patent Document 3 having such a structure can prevent hard particles such as earth and sand from entering the ceramic part forming the sliding surface of the bearing, and damage of the bearing when a fluid force is applied. Can also be avoided.

  On the other hand, the water-lubricated pad-type ceramic bearing device of Patent Document 4 has a structure in which an elastic support mechanism that does not hinder the movement of the bearing is further added on the premise of the structure of the water-lubricated ceramic bearing device of Patent Document 3. . The water-lubricated pad type ceramic bearing device of Patent Document 4 having such a structure does not hinder the movement of the bearing in the radial direction, and can reduce damage to the bearing even when an impact force is applied. it can.

  Further, Patent Document 5 discloses a sliding bearing device that supports a rotating body of a rotating electrical machine such as a water turbine generator as a bearing device for water lubrication. In order to reduce the stirring loss and sliding loss caused by the rotation of the rotating body, this sliding bearing device is made of a resin composite composition whose main component is a polymer material polyether ether ketone. It is composed.

  Further, Patent Document 6 discloses a guide bearing device for a rotating electrical machine including a guide sector that supports a load of a rotating body as a bearing device that enables water lubrication. This guide bearing device uses a material in which a polymer material polyether ether ketone is filled with a fiber material as a sliding surface material of a guide sector, and a lubricating fluid such as water having a viscosity lower than that of turbine oil between the rotating body and the guide sector. And the guide sector is installed in a state of being pressed against the rotating body. In such a guide bearing device, excessive vibration is not generated in the rotating body during operation, and even if the sliding surface material of the guide sector comes into contact with the rotating body, damage can be suppressed to a minimum, and the operation of the rotating electrical machine can be suppressed. Can continue. Further, since a lubricating fluid having a viscosity lower than that of the turbine oil is used, loss generated in the guide bearing device can be reduced.

JP 2001-124070 A JP-A-8-86268 Japanese Patent Laid-Open No. 8-145051 JP-A-8-338428 JP 2001-234930 A JP 2003-28146 A

  In water turbines, drainage pumps, and the like, it is desirable that a structure that can use river water as a lubricant in the bearing device can eliminate the need for supplying fresh water for lubrication. However, when river water is used for lubrication, there is a problem that hard particles such as earth and sand enter the sliding contact surface. In order to solve this problem, the structures disclosed in Patent Document 3 and Patent Document 4, that is, the sliding contact surface of the bearing is elastically pressed against the sliding contact surface of the sleeve at the time of stopping, and the water pressure is exerted by the dynamic pressure effect during rotation. An elastic pressing structure in which a film is formed is effective. By using this elastic pressing structure, the intrusion of hard particles can be effectively prevented.

  As described above, the bearing devices disclosed in Patent Document 3 and Patent Document 4 can effectively prevent intrusion of hard particles due to earth and sand even when river water is used for lubrication. However, in these prior arts, a cemented carbide material is used for the sliding contact surface of the sleeve mounted on the rotating shaft, and a ceramic material is used for the sliding contact surface of the bearing. It can be said that using a cemented carbide material or a ceramic material for the sliding contact surface is extremely excellent in terms of durability of the sliding contact surface. However, the use of a cemented carbide material or ceramic material for the sliding contact surface in the elastic pressing structure as described above does not fully take advantage of the elastic pressing structure. That is, when using an elastic pressing structure that can effectively prevent the invasion of hard particles that cause rapid wear of the sliding contact surface, it is not always necessary to increase the wear resistance of the sliding contact surface so much. . When considered in this way, the use of an expensive cemented carbide material or ceramic material results in excessive quality. In other words, there remains a problem in terms of appropriate material selection in terms of cost performance. In addition, the use of cemented carbide materials and ceramic materials has a problem in impact resistance, and there is a demand for consideration not to give impact when disassembling and assembling the bearing device. It will also bring.

  For this reason, the use of a thermoplastic resin material for the sliding contact surface of the bearing as in the prior art disclosed in Patent Document 1, Patent Document 5 or Patent Document 6 is superior to the case of using a ceramic material. It can be said that. However, in these conventional technologies, polyether ether ketone (referred to as PEEK or PEEK resin as appropriate) is used as the thermoplastic resin material. This is because PEEK is widely used as a sliding material in oil-lubricated bearings, and the actual situation is that it has been used as it is in the case of water lubrication.

  However, the use of PEEK as a thermoplastic resin in water lubrication does not sufficiently utilize the advantages of water lubrication, and as a result, it can be said that the quality is excessive. In other words, PEEK has the highest heat resistance (glass transition temperature of about 150 ° C.) among resin materials, and because of this high heat resistance, it has excellent suitability as a sliding material in oil-lubricated bearings under high temperature conditions. It is recognized. However, in the case of water lubrication, since the viscosity of water is as small as about 1/30 of oil used for oil lubrication (for example, turbine oil VG32), heat generation due to friction loss on the sliding surface is small. Even if the temperature is high, it is about several tens of degrees, heat resistance that can withstand the temperature conditions in oil lubrication is not necessarily required, and expensive PEEK that is several to ten times as high as a general heat-resistant class resin material is used. The use becomes excessive quality.

  The present invention has been made in the background of the above-described circumstances in the water-lubricated bearing device, and a plurality of bearings segmented along the circumferential direction of the rotating shaft are arranged, and each of the bearings is attached to the rotating shaft. The purpose of the water-lubricated segment-type bearing device with an elastic pressing structure that is elastically pressed against the sleeve is to reduce costs by making more effective use of the advantages of the elastic pressing structure and water lubrication. It is another object of the present invention to provide a water turbine using such a water-lubricated segment type bearing device.

For the above purpose, in the present invention, a sleeve mounted on a rotating shaft having a vertical axis, a bearing case disposed on the outer periphery of the sleeve, and the sleeve and the bearing case so as to be in sliding contact with the sleeve, respectively. A plurality of bearings that are segmented along the circumferential direction of the sleeve and a bearing that is attached to the bearing case and stores water used to lubricate the sliding contact surface of the bearing and the sliding contact surface of the sleeve A lubricating water storage frame, wherein the lubricating water storage frame is formed so as to surround the inside of the sleeve, the outside of the bearing case, and the bottom surface of the bearing case, and the sliding contact surface of the bearing as the sleeve. An elastic pressing mechanism that elastically presses the sliding surface of the compression coil spring, pressing the bearing in the radial direction of the rotating shaft, and an adjustment body that adjusts the pressing force of the compression coil spring; And an elastic support mechanism configured to elastically support the bearing only from below, protruding from the upper end of a bearing case disposed on the outer periphery of the sleeve in the direction of the rotation axis, And an upper plate whose tip is in contact with the upper surface of the bearing, a lower plate projecting in the direction of the rotation axis from the lower end of the bearing case, and a lower plate provided between the lower plate and the bearing. An elastic support mechanism including a coil spring that is more elastically supported, and the sliding surface of the bearing is formed by a resin portion using a resin material made of polyphenylene sulfide resin or fluorine resin. It is characterized by that.

  For the above purpose, in the present invention, a sleeve mounted on a rotating shaft having a vertical axis, a bearing case disposed on the outer periphery of the sleeve, and the sleeve and the bearing case so as to be in sliding contact with the sleeve, respectively. A plurality of bearings that are segmented along the circumferential direction of the sleeve and a bearing that is attached to the bearing case and stores water used to lubricate the sliding contact surface of the bearing and the sliding contact surface of the sleeve A lubricating water storage frame, wherein the lubricating water storage frame is formed so as to surround the inside of the sleeve, the outside of the bearing case, and the bottom surface of the bearing case, and the sliding contact surface of the bearing as the sleeve. An elastic pressing mechanism that elastically presses the sliding surface of the compression coil spring, the compression coil spring pressing the bearing in the radial direction of the rotating shaft, and an adjusting body for adjusting the pressing force of the compression coil spring; A columnar plate spring provided between the compression coil spring and the adjusting body, and fixed to the back surface of the bearing by pivots provided in pairs so as to sandwich the compression coil spring vertically An elastic pressing mechanism comprising a plate-shaped plate spring supported by a spherical tip surface of the adjusting body and supported at the center by pressing, and an elastic supporting mechanism for elastically supporting the bearing only from below. An upper plate projecting in the direction of the rotation axis from an upper end portion of a bearing case disposed on an outer periphery of the sleeve, and a tip portion of which is in contact with an upper surface of the bearing, and a lower end portion of the bearing case. A bearing provided with a lower plate projecting in the direction of the rotation axis and a coil spring provided between the lower plate and the bearing and elastically supporting the bearing from below; Sliding contact surface is characterized in that it is formed of a resin portion with a resin material consisting of a polyphenylene sulfide resin or a fluorine resin.

In the present invention, a resin material mixed with carbon fibers is used for the water-lubricated segment type bearing device as described above.
Furthermore, in the present invention, the above-described water-lubricated segment type bearing device is formed of stainless steel obtained by quenching the sleeve.

  Further, in the present invention, for the above purpose, in the water turbine having the rotating shaft supported by the bearing device, the above-described water-lubricated segment type bearing device is used as the bearing device.

  In the present invention, a resin portion is provided on the sliding contact surface of the bearing, and the resin portion is formed of polyphenylene sulfide-based resin or fluorine-based resin. Resin materials are inferior in wear resistance to ceramic materials used in conventional bearing devices, but are superior to ceramic materials in impact resistance, and are also superior to ceramic materials in terms of cost. . For this reason, forming the sliding contact surface of the bearing with a resin material makes it possible to more effectively utilize the advantage of the structure of providing an elastic pressing mechanism that elastically presses the sliding contact surface of the bearing against the sleeve. This leads to improved handling and cost reduction. In other words, providing an elastic pressing mechanism provides the advantage that the wear resistance of the sliding contact surface does not need to be so high, but this advantage is made more effective by using a resin material for the sliding contact surface of the bearing. Since the resin material is superior in impact resistance and cost compared to the ceramic material, it is possible to improve handling at the time of disassembling and assembling the bearing device, and to reduce the cost of the bearing device. .

  In the present invention, polyphenylene sulfide resin or fluorine resin is used as the resin material. For example, polyphenylene sulfide-based resin is superior to PEEK used in conventional bearing devices, although it has a low glass transition temperature of about 90 ° C., which is an index of heat resistance, and is excellent at about 1 that is sufficient in terms of cost. For this reason, using a polyphenylene sulfide-based resin as a resin material leads to cost reduction of the bearing device by utilizing the advantage of water lubrication more effectively. That is, in the case of water lubrication, the temperature of the sliding contact surface does not become 100 ° C. or more at the maximum, and is usually about several tens of degrees C. By using a sulfide-based resin, the cost of the bearing device can be further reduced. This is also true for the case of using a fluororesin.

  Hereinafter, modes for carrying out the present invention will be described. FIG. 1 shows a schematic structure of a water turbine for power generation to which a water lubricated segment type bearing device according to a first embodiment of the present invention is applied. The water wheel shown in FIG. 1 includes a rotating shaft 1, a runner 41 fixed to the lower portion of the rotating shaft 1, a fixed body 42 disposed so that the rotating shaft 1 is inserted above the runner 41, and a rotating shaft on the fixed body 42. 1 has a bearing device 30 that rotatably supports 1, and the water-lubricated segment type bearing device according to the first embodiment of the present invention is used as the bearing device 30. River water can be used as a lubricant. The fixed body 42 has a hollow shape, and the top plate portion 43 supports the rotary shaft 1 via the water-lubricated segment type bearing device 30, and between the upper cover 44 and the rotary shaft 1. A shaft seal device 45 is provided. A casing 47 is formed by the upper cover 44 and the lower cover 46 of the fixed body 42, and the flow rate of water flowing from the casing 47 into the runner 41 can be adjusted by the guide vane 48. The guide vane 48 is connected to a guide ring 49 provided on the casing 47 and is driven by a hydraulic servo (not shown).

  The structure of the water-lubricated segment type bearing device 30 is shown in FIGS. 2 is a longitudinal sectional view of the water-lubricated segment type bearing device 30, and FIG. 3 is a sectional view taken along the line BB in FIG. The water-lubricated segment type bearing device 30 includes a sleeve 2, a bearing case 3, a bearing 4, an elastic pressing mechanism P, an elastic support mechanism S, and a lubricating water storage frame W as main elements.

  The sleeve 2 has a skirt portion 2s. The sleeve 2 is fixedly attached to the rotating shaft 1 through the skirt portion 2s, and functions to receive sliding contact support of the rotating shaft 1 by the bearing 4. The sleeve 2 has a cylindrical structure that can be divided into two along the periphery of the skirt portion 2 s, and the divided semi-cylindrical member is fastened by a reamer bolt 5. In the present invention, the sleeve 2 is quenched and formed of stainless steel, and the stainless steel material forms an outer sliding contact surface 2f. A preferred example of stainless steel is SUS420J2 (JIS standard). Thus, by forming the sleeve 2 and its sliding contact surface 2f with quenching stainless steel, the effect of the elastic pressing mechanism P can be utilized more effectively as described later.

  As shown in FIG. 3, the bearing case 3 has a cylindrical shape and is disposed on the outer periphery of the sleeve 2. As shown in FIG. 2, the bearing case 3 has a lower plate 6 attached to its lower end in the axial direction and an upper plate 7 attached to its upper end. To be surrounded.

  The bearings 4 are arranged in a segmented state between the sleeve 2 and the bearing case 3 so that a plurality (eight in the example of FIG. 3) are in sliding contact with the sleeve 2 along the circumferential direction of the sleeve 2. Is done. The sliding contact surface with respect to the sleeve 2 of each bearing 4 is formed of a resin material. Specifically, a resin portion 8 formed of a resin material is provided on the bearing 4, and the outer surface of the resin portion 8 is used as a sliding contact surface 4 f of the bearing 4. The resin part 8 is bonded and fixed to the bearing 4 with, for example, an epoxy adhesive. Thus, by forming the sliding contact surface 4f of the bearing 4 with a resin material, particularly a fiber reinforced resin material mixed with carbon fibers, the utility of the elastic pressing mechanism P can be utilized more effectively as described later. it can. In the present invention, as the resin material of the resin portion 8, a resin material that can make more effective use of this water lubrication is used because the lubrication in sliding contact with the sleeve 2 is water lubrication. The specific selection criteria are as follows. A resin material has a glass transition temperature as an index of its heat resistance, and a resin material having higher heat resistance is generally more expensive. Therefore, the temperature of the sliding contact surface does not become 100 ° C. or more at the maximum due to water lubrication, and the glass transition temperature may be 100 ° C. or less on the assumption that it is usually about several tens of degrees C. This is one selection criterion. Then, the sliding characteristic of PEEK resin, which has a proven record as a sliding material for bearings, is used as an index, and another selection criterion is to have a sliding characteristic comparable to this. From such selection criteria, in the present invention, as the resin material of the resin portion 8, a PPS resin mainly composed of polyphenylene sulfide (referred to as PPS or PPS resin as appropriate) is used as the most preferable one, and a fluorine resin is also preferable. Use as a thing. The most preferable PPS resin is that the PPS resin has the same sliding characteristics as the PEEK resin that has a proven track record as a sliding material as described later, and such high sliding characteristics. This is because it has been found that it has high characteristics as a sliding material, such as being low-cost while having it, and being able to be easily bonded to the bearing 4 made of a metal material.

  The elastic pressing mechanism P elastically supports the bearing 4 in the radial direction of the rotary shaft 1. For this purpose, the elastic pressing mechanism P includes a compression coil spring 10 that elastically biases the bearing 4 with respect to the sleeve 2 in the radial direction of the rotary shaft 1 and an adjustment body 11 that adjusts the spring force of the compression coil spring 10. Is the main element.

  The compression coil spring 10 cuts the outer peripheral surface of the bearing 4 to an appropriate depth between a pair of opposing walls 12 and 12 projecting from the outer peripheral surface of the bearing 4 so as to face each other. In this state, one end of the groove 13 is pressed against the bearing 4 at the bottom of the groove 13 and the other end is pressed and supported by the adjusting body 11 via the leaf spring 14. It is provided as follows.

  The adjusting body 11 is formed by a bolt structure screwed into a screw hole 15 formed so as to penetrate the bearing case 3 in the radial direction, and the leaf spring 14 is adjusted by adjusting the screwed state into the screw hole 15. The pressing force applied to the compression coil spring 10 via the screw can be adjusted, and the screwed state can be fixed by the nut 16. The adjustment body 11 has a slightly spherical tip surface, and is pressed against the central portion of the leaf spring 14 with the spherical tip surface.

  Here, the leaf spring 14 interposed between the compression coil spring 10 and the adjusting body 11 bears the alignment function of the bearing 4 and is provided in a pair so that the compression coil spring 10 is sandwiched vertically in the state of FIG. Both ends are supported by the pivots 17 and 17, and the center is pressed against and supported by the spherical tip surface of the adjustment body 11 as described above.

  The elastic support of the bearing 4 by the elastic pressing mechanism P as described above has two functions. One is that the sliding contact surface 4f by the resin portion 8 of the bearing 4 is pressed against the sliding contact surface 2f of the sleeve 2 when the rotary shaft 1 is stopped, so that even when river water is used as lubricating water, This is a function of preventing hard particles such as from entering between the sliding contact surface 4f and the sliding contact surface 2f. With this function, it is possible to effectively avoid the possibility of wear of the sliding contact surface due to hard particles such as earth and sand, which becomes a problem when river water is used as lubricating water. The other one is that if the resin portion 8 is worn out, it is possible to prevent the gap between the sliding contact surface 4f and the sliding contact surface 2f from expanding due to the wear and to form a water film for lubrication. This is a function of maintaining a gap suitable for forming.

  By providing the elastic pressing mechanism P in this way, it becomes possible to effectively cope with the wear problem of the sliding contact surface. This brings about the advantage that in the structure in which the bearing 4 is elastically supported by the elastic pressing mechanism P, it is not always necessary to require so high wear resistance on the sliding contact surface. Therefore, in the present invention, in order to utilize this advantage more effectively, the sliding contact surface 2f of the sleeve 2 is formed of quenching stainless steel as described above, and the sliding of the bearing 4 is performed as described above. The contact surface 4f is formed of a resin material, and the PPS resin is most preferably used as the resin material, so that the condition of water lubrication is more effectively utilized.

  The elastic support mechanism S is formed by a coil spring 18 provided between the lower plate 6 of the bearing case 3 and the lower end surface of the bearing 4, and has the function of the bearing case 3 elastically supporting the bearing 4. Yes. Since the bearing 4 is elastically supported by such an elastic support mechanism S, an appropriate biasing force by the compression coil spring 10 in the elastic pressing mechanism P can be applied to the bearing 4 more stably. It becomes like this. As a result, the followability of the bearing 4 is improved, and the formation of a water film in the gap between the sliding contact surface 2f and the sliding contact surface 4f during rotation of the rotary shaft 1 becomes more stable. It is possible to effectively prevent damage caused by the contact of 4 pieces. Further, since the pressing force by the compression coil spring 10 can be set to an appropriate value which is low, the starting frictional force can be suppressed to a small value, and a stable sliding characteristic can be obtained. Two or more coil springs 18 are preferably provided to make the elastic support of the bearing 4 more stable.

  The lubricating water storage frame W is for storing water used for lubrication of the sliding contact surface 2f and the sliding contact surface 4f. The inner cover 20 and the outer cover 21 attached to the bearing case 3, respectively, and FIG. The top plate portion 43 is formed so as to be enclosed in a bowl shape, and an upper plate 22 for preventing scattering of lubricating water is provided on the upper portion thereof.

  Below, the sliding characteristic evaluation test of PPS used as a preferable thing for the resin part 8 is demonstrated. The test was performed by comparing the sliding characteristics of various resin materials with that of PEEK. Specifically, ring-shaped fixed side materials are prepared for each of PPS and other various resins and PEEK reinforced with carbon fiber, and these fixed-side materials are made into ring-shaped rotating side materials manufactured by SUS420J2. The relationship between the friction coefficient and the number of lubrication characteristics (number of bearing characteristics) (S = η · N / P) was measured by sliding while rotating under water lubrication. Here, η: viscosity of tap water at a temperature in the vicinity of the sliding surface (Pa · s), N: rotational speed (rps), and P: sliding surface pressure (Pa). As test conditions, six radial grooves for water lubrication are formed in the fixed side material, and lubricating water (tap water) is introduced into this groove, and the rotating side material is rotated while lubricating the sliding surface with water. With the average peripheral speed maintained at 5 m / s, the sliding surface pressure (test load / sliding area) was increased stepwise and tested until the friction coefficient increased rapidly.

The result of this sliding test is shown in FIG. 4 as a comparison between PPS and PEEK. FIG. 4 shows a Stribeck diagram representing a sliding condition for shifting from fluid lubrication to boundary lubrication, that is, the relationship between the number of lubrication characteristics S = η · N / P and the measured friction coefficient. In this Stribeck diagram, the coefficient of friction decreases as the number of bearing characteristics decreases, and shows a tendency to increase rapidly after a certain critical value. A region having a large number of lubrication characteristics with this critical value as a boundary is called a fluid lubrication region. That is, the smaller the critical value of the number of bearing characteristics, the better the sliding characteristics. As shown in FIG. 4, the number of bearing characteristics that are critical values for PEEK and PPS is 6 × 10 ⁻⁹ , and PPS should stably exhibit sliding characteristics equivalent to PEEK, which has a proven track record as a sliding material. Can be confirmed. From this result, it can be seen that the use of PPS for the resin portion 8 of the bearing 4 provides the same characteristics as when PEEK is used. Here, carbon fiber is mixed in the resin material for fiber reinforcement, but the depression formed by dropping or peeling of the carbon fiber acts as a water reservoir, so that both PPS and PEEK It can be estimated that the sliding characteristics are improved even under high surface pressure conditions. In addition, none of the resin materials other than PPS satisfied the sliding characteristics equivalent to PEEK.

  Next, the wear resistance of the PPS was examined when it was kept in contact at rest and repeated start-stop, which became a non-contact state upon formation of a water film after rotation start. Specifically, in tap water, the relationship between the amount of wear of PPS and the number of times of starting and stopping was measured by a combination of using PPS for the resin portion of the bearing and SUS420J2 for the sleeve of the rotating shaft. As test conditions, contact was made at a surface pressure of 0.024 MPa when stationary, and after starting, the pattern was held for 5 minutes after reaching a peripheral speed of 8 m / s, then stopped and restarted after 5 minutes of stopping time. It was.

  FIG. 5 shows the evaluation results of this wear resistance. As shown in FIG. 5, the wear amount slightly increases with the increase in the number of activations, but after the test of 4000 times, it becomes 0.0015 mm, has sufficient wear resistance, and can be confirmed to be highly practical. From this, it can be seen that even when PPS is used with respect to an elastic pressing structure in which a water film is formed with rotation by pressing with a predetermined pressing force when stationary, it can be sufficiently endured.

  FIG. 6 shows the structure of a water-lubricated segment type bearing device according to the second embodiment of the present invention. The water-lubricated segment type bearing device of the present embodiment is basically the same as the water-lubricated segment type bearing device of the first embodiment, and the first as an elastic biasing means of the elastic pressing mechanism P ′. The difference is that a tension coil spring 25 is used instead of the compression coil spring 10 in the embodiment. The tension coil spring 25 is provided so that a plurality of bearings 4 arranged in a circle in the circumferential direction of the sleeve 2 are collectively wound and pressed. As described above, in the structure using the tension coil spring 25, the compression coil spring 10 needs to be provided for each bearing 4, whereas one tension coil spring 25 is provided for the plurality of bearings 4. Therefore, the workability in the assembly work of the apparatus can be improved. Other configurations are the same as in the case of the first embodiment, and the above description is used for the description thereof. In addition, about this embodiment using the tension coil spring 25, another modification is also possible. That is, it is a form using a rubber ring or the like that exerts a tension spring force similarly to the tension coil spring 25.

  The water-lubricated segment type bearing device of the present invention can be suitably used for supporting a rotating shaft in a rotating device involving water, such as a water wheel or a drainage pump. The present invention for reducing the cost and improving the handleability of such a water-lubricated segment type bearing device can be utilized as effective in the field of rotating devices involving water.

It is a figure which shows schematic structure of the principal part of the water turbine to which the water lubrication segment type bearing device by 1st Embodiment is applied. It is a figure showing the structure of the water lubrication segment type bearing device by a 1st embodiment in the longitudinal section. It is a figure which shows the cross section along the BB line of FIG. It is a figure which shows the result of a sliding test as a comparison of PPS and PEEK. It is a figure which shows the evaluation result of the abrasion resistance of PPS. It is a figure which shows the structure of the water-lubricated segment type | mold bearing apparatus by 2nd Embodiment as a longitudinal cross-section.

DESCRIPTION OF SYMBOLS 1 Rotating shaft 2 Sleeve 2f Sliding contact surface of sleeve 3 Bearing case 4 Bearing 4f Sliding contact surface of bearing 8 Resin part P Elastic pressing mechanism

Claims (5)

A sleeve mounted on a rotating shaft consisting of a vertical axis;
A bearing case disposed on the outer periphery of the sleeve;
A plurality of bearings that are segmented along the circumferential direction of the sleeve between the sleeve and the bearing case so that each is in sliding contact with the sleeve;
Attached to the bearing case and used to lubricate the sliding contact surface of the bearing and the sliding contact surface of the sleeve.
A lubricating water storage frame for storing water, wherein the lubricating water storage frame is formed so as to surround the inside of the sleeve and the outside of the bearing case and the bottom surface of the bearing case;
An elastic pressing mechanism that elastically presses the sliding contact surface of the bearing against the sliding contact surface of the sleeve, the compression coil spring pressing the bearing in the radial direction of the rotating shaft, and the compression coil spring An elastic pressing mechanism comprising an adjusting body for adjusting the pressing force;
An elastic support mechanism that elastically supports the bearing only from below, and protrudes from the upper end portion of the bearing case disposed on the outer periphery of the sleeve in the direction of the rotation axis, and the front end portion contacts the upper surface of the bearing. An upper plate, a lower plate projecting in the direction of the rotation axis from the lower end of the bearing case, and a coil spring provided between the lower plate and the bearing and elastically supporting the bearing from below. An elastic support mechanism,
The water-lubricated segment type bearing device, wherein the sliding contact surface of the bearing is formed by a resin portion using a resin material made of polyphenylene sulfide resin or fluorine resin. A sleeve mounted on a rotating shaft consisting of a vertical axis;
  A bearing case disposed on the outer periphery of the sleeve;
  A plurality of bearings that are segmented along the circumferential direction of the sleeve between the sleeve and the bearing case so that each is in sliding contact with the sleeve;
  Attached to the bearing case and used to lubricate the sliding contact surface of the bearing and the sliding contact surface of the sleeve.
A lubricating water storage frame for storing water, wherein the lubricating water storage frame is formed so as to surround the inside of the sleeve and the outside of the bearing case and the bottom surface of the bearing case;
  An elastic pressing mechanism that elastically presses the sliding contact surface of the bearing against the sliding contact surface of the sleeve, and includes a compression coil spring that presses the bearing in a radial direction of the rotating shaft, and a compression coil spring. An adjustment body for adjusting the pressing force and a columnar plate spring provided between the compression coil spring and the adjustment body, the pair being fixed to the back surface of the bearing and sandwiching the compression coil spring vertically An elastic pressing mechanism composed of a columnar plate spring supported at both ends by a pivot provided as described above and pressed against and supported by the spherical tip surface of the adjustment body;
  An elastic support mechanism that elastically supports the bearing only from below, and protrudes in the direction of the rotation axis from the upper end portion of a bearing case disposed on the outer periphery of the sleeve, and the front end portion contacts the upper surface of the bearing. An upper plate, a lower plate projecting in the direction of the rotation axis from the lower end of the bearing case, and a coil spring provided between the lower plate and the bearing to elastically support the bearing from below. An elastic support mechanism,
  A water-lubricated segment type bearing device, wherein the sliding contact surface of the bearing is formed by a resin portion using a resin material made of polyphenylene sulfide resin or fluorine resin.   The water-lubricated segment type bearing device according to claim 1 or 2, wherein carbon fiber is mixed in the resin material.   The water-lubricated segment type according to any one of claims 1 to 3, wherein the sliding surface of the sleeve facing the sliding surface of the bearing formed of the resin portion is formed of quenched stainless steel. Bearing device.   A water turbine having a rotating shaft composed of a longitudinal axis supported by a bearing device, wherein the water-lubricated segment type bearing device according to any one of claims 1 to 4 is used as the bearing device. Water wheel.

Images