JP2001124070A - Water lubricated bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water lubricated bearing device in which sufficient withstand load property is ensured and damage of both a sleeve and a bearing can be decreased even when partial loading is generated, and to provide a pump and a hydraulic turbine of high reliability using the water lubricated bearing device, in the water lubricated bearing device supporting a rotation shaft of the pump and the hydraulic turbine. SOLUTION: In this water lubricated bearing device, the sleeve is fixed to the rotation shaft. The water lubricated bearing is constituted of: a bearing case arranged at an outer peripheral position of the sleeve; and a bearing arranged in a clearance formed by an inner peripheral side of the bearing case and an outer peripheral side of the sleeve. In this device, sleeve material is made of hard metal having corrosion resistance, and a thermal flexible resin material is arranged to a sliding surface of the bearing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-lubricated bearing device for supporting a rotary shaft of a pump or a water turbine, and more particularly to a bearing device having sufficient load resistance and damage prevention under water lubrication and the bearing. The present invention relates to a pump and a water turbine provided with a device.

[0002]

2. Description of the Related Art Conventionally, as a water-lubricated bearing device for a pump, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 08-042571. In this prior art, a cemented carbide is used for the sleeve, and a ceramic of silicon carbide is used for the bearing side. Both the cemented carbide of the sleeve and silicon carbide on the bearing side are excellent in wear resistance due to the high hardness material. Further, in the case of ceramic bearings, an elastic support structure is frequently used from the viewpoint of avoiding damage caused by contact with one side.

On the other hand, as a water lubricated bearing device for a water turbine, there is one disclosed in Japanese Patent Application No. 49-148119, for example. In this conventional technique, SUS403 is used for the sleeve, and phenol resin (thermosetting resin) is used for the bearing side.

[0004]

As described above, in the prior art ceramic bearing, when the sleeve is eccentrically inclined in the direction of the action of the fluid force during operation, the bearing tends to follow the sleeve. First, the lower end surface (or the upper end surface) of the bearing portion comes into contact with the sleeve, and the sleeve and the bearing are both damaged, which may cause breakage. Further, since the elastic support structure is employed, the number of parts is larger than that of the rigid support structure, so that it is expected that the cost will be high.

[0005] On the other hand, in a bearing using a phenol resin (thermosetting resin), the phenol resin has a swelling phenomenon due to suction of water. For this reason, the bearing clearance becomes smaller than the initial set value during use, and there is a possibility that the sleeve will be tightened, and it is necessary to widen the initial bearing clearance. If the bearing clearance is wide, the water film thickness is about 1 μm under water lubrication conditions, and it is considered that sufficient load resistance cannot be obtained.
Also, in this material combination, under high load conditions, both the sleeve and the bearing may be damaged due to one-side contact or the like.

SUMMARY OF THE INVENTION An object of the present invention is to provide a water-lubricated bearing device capable of ensuring sufficient load resistance and preventing damage to both a sleeve and a bearing even if a partial contact occurs in view of the above-mentioned problems of the prior art. Another object of the present invention is to provide a pump and a water turbine that can obtain high reliability by using the water-lubricated bearing device.

[0007]

The above object can be achieved as follows.

(1) A water bearing in which a sleeve is fixed to a rotating shaft, and a bearing case is disposed at an outer peripheral position of the sleeve, and a bearing is provided in a gap formed between an inner peripheral side of the bearing case and an outer peripheral side of the sleeve. In the lubricated bearing device, the sleeve material is made of a hard metal having corrosion resistance, and a thermoplastic resin layer is disposed on a sliding surface of the bearing.

(2) A water bearing in which a sleeve is fixed to a rotating shaft, and a bearing case is disposed at an outer peripheral position of the sleeve, and a bearing is provided in a gap defined by an inner peripheral side of the bearing case and an outer peripheral side of the sleeve. In the lubricated bearing device, the sleeve material is made of a hard metal having corrosion resistance, and a polyether ether ketone resin is disposed on a sliding surface of the bearing.

(3) A sleeve in which a sleeve is fixed to a rotating shaft, and a bearing case is disposed at an outer peripheral position of the sleeve, and a bearing is provided in a gap defined by an inner peripheral side of the bearing case and an outer peripheral side of the sleeve. In the lubricated bearing device, a coating of a hard metal having corrosion resistance is formed on the sliding surface of the sleeve, and a thermoplastic resin layer is disposed on the sliding surface of the bearing.

(4) A sleeve in which a sleeve is fixed to a rotating shaft, and a bearing case is provided at an outer peripheral position of the sleeve, and a bearing is provided in a gap defined by an inner peripheral side of the bearing case and an outer peripheral side of the sleeve. In the lubricated bearing device, a coating of a hard metal having corrosion resistance is formed on the sliding surface of the sleeve, and polyether ether ketone resin is disposed on the sliding surface of the bearing.

(5) A gap formed by a rotating shaft, a sleeve fixed to the rotating shaft, a bearing case disposed at an outer peripheral position of the sleeve, and an inner peripheral side of the bearing case and an outer peripheral side of the sleeve. In a pump having a water-lubricated bearing device configured with an installed bearing, the water-lubricated bearing device is made of a cemented carbide alloy having a sleeve material having corrosion resistance, and a thermoplastic resin layer is disposed on a sliding surface of the bearing. That

(6) A rotating shaft, a runner having a sleeve fixed to the rotating shaft and fixed to a lower portion of the rotating shaft, a fixed member having a runner disposed therein and having the rotating shaft inserted therethrough, and a fixing member. And a water turbine having a water-lubricated bearing device mounted between the rotating shafts and rotatably supporting the rotating shaft, wherein the water-lubricated bearing device is made of a cemented carbide alloy having a sleeve material having corrosion resistance, and a sliding surface of the bearing The thermoplastic resin layer must be arranged.

(7) In (1) to (4), the cemented carbide alloy having corrosion resistance formed on the sleeve is made of WC-
Ni-based cemented carbide.

As in the case of the water-lubricated bearing device of the present invention, when the sleeve is made of a hard metal having corrosion resistance and the bearing is made of a thermoplastic resin, the sliding test under water lubrication is stable up to a high load region. A low coefficient of friction is obtained. This is because cemented carbide is excellent in heat resistance and wear resistance, and in the high load area, even if water film breakage occurs locally, the sliding surface of the bearing softens and plastic flow easily occurs When it becomes smooth, the plastic flow ends, and it stabilizes in a conformed state. Further, since the thermoplastic resin easily plastically flows at the local contact portion, the cemented carbide is not damaged. Further, it was confirmed by a test that when the cemented carbide and the thermoplastic resin were combined, there was no fusion to the cemented carbide side. Since the thermoplastic resin does not swell, the initial bearing clearance can be reduced, so that sufficient load resistance can be obtained. Since the cemented carbide has corrosion resistance, the shape of the sliding surface does not change with time and is stable. Sufficient load resistance for long-term use is secured, and stable bearing performance is obtained. Further, by using the water-lubricated bearing device, a highly reliable pump and water turbine can be provided.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a schematic view showing a bearing device for a pump according to an embodiment of the present invention. A sleeve 2 made of SUS304 is mounted on the rotating shaft 1, and the sleeve 2 is fixed to the rotating shaft 1 by a detent 3, and its surface is coated with a corrosion-resistant cemented carbide film 4.

A bearing 8 made of a thermoplastic resin layer 5 is disposed at a position where the bearing 8 slides opposite to the sleeve 2.
Are supported by a bearing case 7 via a back metal 6 to which a resin layer 5 is fixed. The bearing case 7 is fixed and supported on a pump casing (not shown). The material for forming the corrosion-resistant cemented carbide film is WC-N
i-type cemented carbide. On the other hand, the material forming the thermoplastic resin layer is a PEEK (polyetheretherketone) resin.

The bearing device 11 was operated under the following conditions of tap water lubrication, and the temperature of the bearing, damage to the sliding surface, and the like were examined.

<Operating conditions> Circumferential velocity: 5 m / s, surface pressure: 1 MPa, operating time: 1 hour.
The measured temperature at the position of mm is stabilized 30 minutes after the start of operation,
Thereafter, the temperature was kept constant at a temperature rise of 3 ° C. with respect to the water temperature, and there was no rapid temperature change. Since there was no sudden rise in the bearing temperature, it was confirmed that in this material combination, sufficient load resistance and stable sliding characteristics could be obtained. One hour later, when the bearing was disassembled and inspected, no damage was found on the sliding surfaces of the sleeve and the thermoplastic resin layer. Further, no trace of corrosion was observed on the surface of the cemented carbide film coated on the sleeve. The actual measurement of the inner diameter of the thermoplastic resin layer before and after the test revealed that there was no change in the inner diameter before and after the test and no dimensional change due to swelling, and it was confirmed that stable bearing performance could be maintained from the beginning.

As described above, by using the water-lubricated bearing device of the present invention, it is possible to provide a water-lubricated bearing capable of securing sufficient load resistance and preventing both the sleeve and the bearing from being damaged due to a contact. became. Further, in order to confirm the effect of the combination of the sliding members of the present invention, the sliding by combining a ring (rotating material) and a plate shape (fixing material, with six radiation grooves for water lubrication) for various materials. A dynamic element test was performed to examine the relationship between the load and the average friction coefficient, and the damage of the sliding surface.

Note that, from the viewpoint of load resistance, the target value of the critical surface pressure is 5 MPa or more.

The results are shown in Table 1 and FIG.

[0024]

[Table 1]

<Operating conditions> Circumferential speed: 5 m / s constant, Surface pressure: Until the load at which the coefficient of friction starts to rise sharply, Sliding time: About 15 to 30 minutes at each load It is of the same quality as the hard metal having corrosion resistance shown in FIG. Cemented carbide solids are cemented carbides with cobalt binder and have low corrosion resistance. PEEK
The resin is a thermoplastic resin of the same quality as the resin shown in FIG.

As shown in Table 1 above, the test pieces No. 1
The combination of the present invention has the highest critical surface pressure. In addition, almost no damage was observed on the sliding surface after the test on both the rotating side and the fixed side. On the other hand, for comparison, the combination of SUS403 and phenolic resin used in current bearings,
Table 1 shows the characteristics of the combination of the cemented carbide solid and SiC. Test piece No. The combination of No. 2 had a low critical surface pressure, and the sliding surface after the test showed slight damage on both the rotating side and the fixed side. Test piece No. The combination of 3 is test piece N
o. Although slightly lower than the critical surface pressure of 1, the sliding surface after the test showed slight damage on both the rotating side and the fixed side. Further, Table 1 shows the characteristics of the combination of S45C and PEEK having a hardness of HRC52 by heat treatment on the rotating side. Test piece No. The combination of test piece No. 4 In this case, the sliding surface after the test was slightly damaged only on the rotating side after the test.

FIG. 2 shows the relationship between the friction coefficient and the load of the above four types of test pieces. As shown in these figures, the test pieces No. The coefficient of friction in the combination of No. 1 (the present invention) shows a decreasing tendency with an increase in load, and starts to increase when it exceeds 7 MPa. Test piece No. The coefficient of friction in the combination of Test No. 4 Unlike the case of the combination of No. 1 (the present invention), it shows a slight increasing tendency as the load increases, and increases when the load exceeds 4 MPa. Test piece No. No. 2 and the test piece No. 2 The combination of test piece No. 3 1 (the present invention) shows a tendency similar to that of the combination, and the friction coefficient starts to increase when the load exceeds 5 MPa and 0.5 MPa, respectively.

As described above, the PEEK resin can obtain a sufficient load resistance (5 MPa or more) only when combined with a cemented carbide having corrosion resistance as shown in the present invention, and has a rotating side and a fixed side. Both damages can be prevented.

The material for forming the thermoplastic resin layer is a PEEK (polyether ether ketone) resin and preferably contains carbon fibers. When carbon fibers are mixed, the mechanical strength is improved.

The case where the bearing device of the present invention is applied to a horizontal shaft pump will be described.

As shown in FIG. 3, the rotating shaft 1 and the rotating shaft 1
, A casing penetrating portion 10a, 10b through which the rotating shaft 1 passes, and the casing penetrating portion.
Bearing device 11 of this embodiment fixed to 10a, 10b
a and a shaft sealing device 12 disposed outside the bearing device 11a.
And Further, a coupling 13 is fixed to one end. In this bearing device, a sleeve 2 made of SUS304 is mounted on a rotating shaft 1, the sleeve 2 is fixed to the rotating shaft 1 by a detent 4, and a corrosion-resistant cemented carbide coating 4 is formed on the surface thereof. Coated. The sleeve 2
A bearing 8 made of a thermoplastic resin layer 5 is arranged at a position where the bearing 8 slides in opposition to the bearing, and the bearing 8 is supported by a bearing case 7 via a back metal 6 to which the resin layer is fixed. The bearing case 7 is fixed to and supported by the casing through portions 10a and 10b.

Since this pump is a push-in type for tap water, the bearing device 11a is always filled with water. Since this bearing device is made of a combination of cemented carbide and thermoplastic resin with sufficient load-bearing capacity, a sufficient water film is formed between the bearing and the sleeve fixed to the rotating shaft at the same time as starting, and stable Bearing performance is obtained. In addition, during operation of the pump, the periphery of the bearing is cooled by the pumped liquid, so that the bearing temperature can be kept low, and the water film thickness increases due to the increase in the viscosity of the water, thereby improving the reliability. In addition, since the bearing is excellent in load resistance, the bearing width can be reduced as compared with the conventional method, so that the pump can be made compact, the installation area of the pump can be reduced, and the cost of the pump equipment can be reduced.

Next, a case where the present invention is applied to a vertical rainwater drainage pump according to the present invention will be described.

That is, as shown in FIG. 4, the vertical shaft drain pump is composed of a rotating shaft 1 and a runner 9a fixed below the rotating shaft 1.
And a pump casing 14 through which the pump main shaft 1 is inserted and in which a water flow path is formed, and a guide bearing device of the present invention which is mounted above the pump casing 14 and rotatably supports the pump main shaft. 11b and a thrust bearing device 11c.

As shown in FIG. 5, the guide bearing device 11b includes a SUS304 sleeve 2a fixed to the rotating shaft 1,
The surface of the sleeve 2a has a corrosion-resistant cemented carbide coating 4a.
Is coated. A bearing case 7a arranged at an outer peripheral position of the sleeve 2a, and a plurality of segments arranged along the circumferential direction between the bearing case 7a and the sleeve 2a, and sliding at a position facing the sleeve 2a. A guide bearing 8a having a thermoplastic resin layer 5a formed thereon, and a water tank 16 for storing lubricating water 15 for the bearing 8a. Here, the structure is such that the rear surface of the bearing 8a is supported by the adjustment bolt 17, but a structure in which the bearing 8a is directly fixed to the bearing case 4 without the adjustment bolt 17 may be employed, and the bearing structure is not particularly limited.

On the other hand, the thrust bearing device 11c is
8 and supports the rotating shaft 1. As shown in FIG.
9 is fixed, and the outer periphery of the thrust block 19 is coated with a corrosion-resistant cemented carbide film 4b. Bearing case 7b arranged at an outer peripheral position of this thrust block 19
A segment-shaped bearing 8b in which a plurality of sliding portions are provided along the circumferential direction between the bearing case 7b and the thrust block 19 and a thermoplastic resin layer 5b is formed, and a collar 20 attached to the lower surface of the thrust block. A plurality of sliding portions disposed opposite to the collar 20 are provided with a thermoplastic resin layer 5c.
Are formed, and a water tank 16a for storing the lubricating liquid 15 for these bearings. The lower surface of the collar 20 is coated with a corrosion-resistant cemented carbide film 4c. The pad-type thrust bearing 11c is mounted on a bearing casing 22.

Since this bearing device is made of a combination of a cemented carbide and a thermoplastic resin having sufficient load resistance, a sufficient water film is formed between the bearing and the sleeve fixed to the rotating shaft at the same time as starting. , Stable bearing performance is obtained. Also,
Since the thermoplastic resin does not change its shape due to swelling, the initial bearing sliding surface shape can be maintained for a long period of time, so that the reliability for long-term operation is significantly improved. In addition, since the combination of the cemented carbide and the thermoplastic resin has good conformability, the sliding surfaces of the sleeve and the bearing have small and smooth sliding surfaces. Therefore, the formation of the water film becomes good immediately after the start, and the load resistance is improved.

In the illustrated embodiment described so far, an example is shown in which the bearing devices 11a, 11b, 11c are applied to a pump. However, similar effects can be obtained by applying them to a water turbine. In that case, in the first embodiment, the bearing case 7 is
In this embodiment, the bearing case 7a can be used by attaching it to a fixed member of a water turbine.

Next, a case where the bearing device of the present invention is applied to a water turbine will be described.

That is, as shown in FIG.
0, a runner 41 fixed to the lower part of the rotating shaft 40, a fixed body 42 disposed on the runner 41 and penetrating the rotating shaft 40, and the present embodiment in which the rotating shaft 40 is rotatably supported by the fixed body 42. And an example bearing device 11d. Fixed body 4
Numeral 2 has a hollow shape. The rotary shaft 40 is supported on the top plate 43 via the bearing 8c, and a shaft sealing device 45 is provided between the upper cover 44 and the rotary shaft 40. A casing 46 is formed by the upper cover 43 and the lower cover 44 of the fixed body 42.
Is adjusted by the guide vanes 47. The guide vane 47 is connected to a guide ring 48 provided on the top plate 43, and is driven by a servomotor 49.

As shown in FIG. 8, the bearing device includes a sleeve 2b fixed to the rotating shaft 40, a bearing case 7c, a bearing 8c, and a water tank 16.

As shown in FIG. 8, the sleeve 2b is divided into two parts along the periphery of the rotating shaft 40, and both ends in the axial direction of the divided two members are fastened by bolts 23, so that the periphery of the rotating shaft 40 is formed. I'm wearing it. As in the first embodiment, a cemented carbide portion 4c is provided on the sliding surface of the outer periphery of the sleeve 2b with the bearing 8c.

The bearing case 7c is formed in a cylindrical shape, and leaf springs 24a and 24b projecting to both end faces of the bearing 8c are attached to both ends (up and down) in the axial direction.
The axial force of the bearing 8c is absorbed and relieved by the elastic force of a and 24b. A plurality of bearings 8c are provided along the periphery between the sleeve 2b and the bearing case 7c, and a sliding surface of the sleeve 2b with the cemented carbide portion 4c is formed of a thermoplastic resin layer as in the first embodiment. 5d is provided.
The water tank 16 includes a bottom surface of the bearing case 7c and an inner cylinder 16b and an outer cylinder 6c provided so as to surround the bearing case 7c.

The bearing 8c holds the bearing clearance and is positioned in the radial direction by the adjusting body 24.

Since a bearing device combining a cemented carbide and a thermoplastic resin capable of avoiding sufficient load resistance and damage prevention is mounted, the same effect as a pump can be obtained. Also,
In particular, in the case of a water turbine, since the thermoplastic resin does not change its shape due to swelling, the initial bearing clearance can be made smaller than that of a conventional phenol resin. As a result, since the bearing rigidity can be increased, the vibration of the rotating shaft can be suppressed to a small level, and a water turbine with small vibration can be achieved.

Therefore, the water turbine having the bearing device of the present invention can obtain high reliability as a water turbine.

[0047]

As described above, in the bearing device of the present invention, since the sleeve is made of a hard metal having corrosion resistance and the bearing is made of a thermoplastic resin, it is stable up to a high load region under water lubrication. A low coefficient of friction is obtained, and it has sufficient load bearing capacity. In addition, since the cemented carbide and the thermoplastic resin are combined, damage to both the sleeve and the bearing due to one-side contact can be prevented, and stable performance can be maintained. Since the thermoplastic resin has no swelling, the initial bearing clearance can be reduced, so that the rigidity of the bearing can be increased. Further, by using the water-lubricated bearing device, a highly reliable pump and water turbine can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a first embodiment of a water-lubricated bearing device according to the present invention.

FIG. 2 is an explanatory diagram showing the results of measuring the friction coefficients of the material combination of the present invention and the material combination of the prior art.

FIG. 3 is a schematic sectional view showing a state in which the water-lubricated bearing device according to the present invention is applied to a horizontal shaft pump.

FIG. 4 is a schematic sectional view showing a state in which the water-lubricated bearing device according to the present invention is applied to a vertical shaft pump.

FIG. 5 is a sectional view showing a second embodiment of the water-lubricated bearing device according to the present invention.

FIG. 6 is a sectional view showing a third embodiment of the water-lubricated bearing device according to the present invention.

FIG. 7 is a schematic sectional view showing a state in which the water-lubricated bearing device according to the present invention is applied to a water turbine.

FIG. 8 is a sectional view showing a fourth embodiment of the water-lubricated bearing device according to the present invention.

[Explanation of symbols]

1, 40: rotating shaft, 2, 2b: sleeve, 3: non-rotating, 4, 4a, 4b, 4c: cemented carbide coating, 5, 5a,
5b, 5c, 5d: thermoplastic resin layer, 6: back metal, 7: bearing case, 8: bearing, 9, 9a, 41: runner, 10a, 10b: casing through portion, 11, 11a,
11b, 11c, 30 ... bearing device, 14 ... pump casing, 17 ... adjustment bolt, 19 ... thrust block, 2
0: Collar, 21: Thrust bearing, 23: Bolt, 24
a, 24b: leaf spring; 25: adjusting body.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideki Akiba 603, Kandamachi, Tsuchiura-shi, Ibaraki Pref. Within the Tsuchiura Works, Hitachi, Ltd. F-term in Tsuchiura Works (reference) 3H022 AA01 BA06 CA13 CA46 CA54 DA14 3H072 AA17 BB23 CC10 3J011 BA02 DA01 JA02 KA02 QA05 SC20

Claims (1)

[Claims] 1. A water lubrication system in which a sleeve is fixed to a rotating shaft, and a bearing case is disposed at an outer peripheral position of the sleeve, and a bearing is provided in a gap defined by an inner peripheral side of the bearing case and an outer peripheral side of the sleeve. A water-lubricated bearing device, wherein the sleeve material is a hard metal having corrosion resistance, and a thermoplastic resin layer is disposed on a sliding surface of the bearing.