JP2002303297A - Horizontal shaft type pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably operate for a long term without maintenance and improve reliability by preventing damage due to a partial load of a radial bearing in a horizontal shaft type pump such as a double suction volute pump or a horizontal shaft drainage pump. SOLUTION: A water passage is formed by surrounding a blade 2 fixed to a pump shaft 1 by a pump casing 3. Both sides of the pump shaft 1 are supported by bearings, a bearing in one side is formed by a radial bearing 4a comprising a sliding bearing, and a bearing in another side is formed by a radial bearing 4a comprising a sliding bearing and thrust bearings 4b and 4c arranged side by side to the radial bearing 4a. Sliding parts of both radial bearings 4a are formed by thermoplastic resin, and pumped water of the pump is used as lubricant for all bearings 4a, 4b, and 4c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal-shaft pump, and more particularly to a horizontal-shaft pump used as a pump for draining rainwater or for supplying clean water.

[0002]

2. Description of the Related Art This type of horizontal shaft type pump includes a double suction centrifugal pump and a horizontal shaft drainage pump. A conventional double suction centrifugal pump includes a pump main shaft with fixed blades, a pump casing surrounding the outer periphery of the blades to form a water passage, and bearings that support the pump main shaft on both sides of the portion where the blades are fixed. The bearing on one side is formed of a ceramic radial bearing consisting of a sliding bearing lubricated by pumping, and is held by the side surface of the pump casing facing the water passage,
Some bearings are formed of a radial bearing consisting of oil-lubricated white metal or grease-lubricated rolling bearings and a thrust bearing juxtaposed to the other, and are held at a position outwardly away from the pump casing. (Prior art 1). Related to this is, for example,
No. 137,795.

Further, as a conventional horizontal shaft drain pump, a pump main shaft to which blades are fixed, a pump casing surrounding a periphery of the blades to form a water passage, and a pump main shaft to be supported on both sides of a portion to which the blades are fixed. The bearing on one side is formed of a ceramic radial bearing consisting of a sliding bearing that lubricates by pumping water, and is held in the pump casing.The other side bearing is made of oil-lubricated white metal or grease lubricated. There is a radial bearing composed of a rolling bearing and a thrust bearing juxtaposed with the radial bearing and configured to be held at a position away from a pump casing (prior art 2). For example, Japanese Patent Application Laid-Open No. H11-93885 relates to this.

[0004]

However, in the prior arts 1 and 2, the bearings on the other side are radial bearings composed of oil-lubricated white metal or grease-lubricated rolling bearings. It is necessary to periodically replace the lubricating oil and grease, which makes maintenance-free difficult, and the lubricating oil and grease may leak and contaminate the surroundings.

Further, in the prior arts 1 and 2, since the bearing on the other side is configured to be held at a position away from the pump casing, the radial support span between the two bearings becomes longer, and vibration during high-speed rotation is increased. And it was difficult to reduce the size and speed.

Further, in the prior arts 1 and 2, the bearings on one side are formed of ceramic radial bearings composed of sliding bearings lubricated by pumping water, so that they are excellent in wear resistance, but are subject to aging. When the pump main shaft is misaligned or the pump main shaft is tilted due to fluid force during operation, the end of the ceramic radial bearing comes into one-side contact with the pump main shaft. Film breakage may occur, and both the pump main shaft and the radial bearing may be damaged.

An object of the present invention is to provide a highly reliable horizontal shaft type pump which is maintenance-free and can be operated stably for a long period of time, and which can prevent damage due to radial contact of the radial bearing.

Another object of the present invention is to provide a horizontal shaft type pump which is maintenance-free and which can reduce vibrations at high speed rotation and can reduce the size and speed of the pump and improve efficiency.

[0009]

Means for Solving the Problems To achieve the above object, a horizontal shaft type pump, which is one of the representative inventions of the present invention, comprises a pump main shaft to which blades are fixed and an outer periphery of the blades. In a horizontal shaft type pump including a pump casing forming a water passage, and bearings supporting the pump main shaft on both sides of a portion to which the blade is fixed, one of the bearings is formed of a radial bearing including a sliding bearing. In addition, the bearing on the other side is formed of a radial bearing composed of a sliding bearing and a thrust bearing juxtaposed thereto, and the sliding portions of both radial bearings are formed of a thermoplastic resin, and lubrication of all the bearings is performed. It is configured to use pumping water as the agent.

[0010] In order to achieve the another object, a horizontal shaft type pump according to one of the representative inventions of the present invention has a pump main shaft to which blades are fixed, and a water passage surrounding the outer periphery of the blades. And a bearing for supporting the pump main shaft on both sides of a portion to which the blades are fixed, wherein the bearing on one side is formed by a radial bearing and the bearing on the other side is provided. Is formed by a radial bearing and a thrust bearing juxtaposed to the radial bearing, the other radial bearing is held by a water passage portion of the pump casing, and pumping water is used as a lubricant for all the bearings. It was done.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In the embodiments after the second embodiment, the first
A duplicate description of the configuration common to the embodiment is omitted. The same reference numerals in the drawings of the respective embodiments indicate the same or corresponding components.

First, a first embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of a double suction centrifugal pump showing a first embodiment of the present invention, FIG. 2 is an enlarged view of a bearing portion on one side of the double suction centrifugal pump of FIG. 1, and FIG. It is an enlarged view of the bearing part of the other side of a pump.

The double-suction volute pump constituting the horizontal shaft type pump is used as, for example, a pump for rainwater drainage or water supply, and includes a pump main shaft 1, blades 2, a pump casing 3, a radial bearing 4a, Thrust bearing 4
b, 4c, a thrust collar 5, a casing cover 6, a seal 7, and the like.

A pump main shaft 1 made of double-layer stainless steel is horizontally supported by a pump casing 3 via a bearing, and has one end protruding outside the pump casing 3. The coupling part 16 connected to the drive mechanism is attached to this one end. The blades 2 are fixed to the outer periphery of the central portion of the pump main shaft 1 and rotate together with the pump main shaft 1, so as to suck water from both sides and discharge the water in the outer peripheral direction. The pump casing 3 is provided so as to surround the outer circumference of the blade 2, and bearing support portions 3 a are provided on both side surfaces facing the water passage. Bearings 4 a, 4 b, 4 c for supporting the pump main shaft 1 are arranged on both sides of the blade 2.

The two radial bearings 4a formed of cylindrical sliding bearings are fixed in close contact with bearing support portions 3a provided on both side surfaces of the pump casing 3, and the pump spindle 1
The portions located on both sides of the blade 2 are rotatably slidably supported. The pump casing portion located on the water passage side (inside) of the radial bearing 4a has a gap with the pump main shaft 1 so that the inside of the radial bearing 4a communicates with the water passage in the pump casing 3. It is configured.
As a result, the pump casing 3 is provided on the radial bearing 4a.
Pumped water is supplied in the inner waterway. In the radial bearing 4a, a plurality of grooves (two in this embodiment) are provided at the horizontal position so as to penetrate in the axial direction. Thereby, pumping water is circulated from the water passage through the plurality of grooves, and the sliding surface of the radial bearing 4a is reliably lubricated.

As shown in FIGS. 2 and 3, the radial bearing 4a is provided with a thermoplastic resin material 4a2 on a sliding surface, and specifically, a back metal 4a0 (material: SUS31).
6, Sintered filter 4)
a1 (material: corrosion-resistant material such as SUS316 or SUS304) is joined by nickel brazing or the like, and a thermoplastic resin material 4a2 is press-fitted to the surface of the joined sintered filter 4a1 and attached using an anchor effect. ing. As the thermoplastic resin material 4a2, a polyetheretherketone resin (hereinafter, referred to as a PEEK-based resin) in which carbon fibers are mixed or not mixed is used.

Here, the radial bearing 4a is manufactured by forming the resin layer 4a2 only on the sliding surface, but the radial bearing 4a is manufactured only by the resin ring or the resin pipe without using the backing metal. It may be attached directly to the pump casing 3 (see FIG. 5 of the third embodiment). Also,
Pumping water penetrates between the back metal 4a0 and the sintered filter 4a1,
Waterproof to prevent corrosion and pitting.
In this waterproofing treatment, a coating film is formed with an adhesive or the like on the remaining portion of the resin bearing except for the sliding surface, so that the inflow of pumped water is reliably prevented. If a corrosion-resistant metal plate is fixed after forming a coating film,
Further, reliability can be improved.

The casing cover 17 has a radial bearing 4a.
And is detachably fixed with a bolt or the like in close contact with the side surface of the pump casing 3 so as to cover the outside of the pump casing 3. And
The seal 7 is provided to prevent water from leaking outside through a gap between the pump main shaft 1 and the casing cover 17.

The radial bearing 4a on the coupling side shown in FIG. 2 and the radial bearing 4a on the other side shown in FIG. 3 have basically the same structure, but the radial bearing 4a on the other side has a thrust metal 4a0 on the back metal 4a0. The difference is that a flange portion 8 for attaching the bearing 4c is formed.

In FIG. 3, the casing cover 6 covers the pump bearing 3 so as to cover the outside of the radial bearing 4a.
And is detachably fixed by bolts or the like. And, the thrust collar 5 is connected to the thrust bearing 4
b, 4c, which receives the thrust force of the casing cover 6 in contact with the other end surface of the pump main shaft 1.
And fixed to the pump main shaft 1 by bolts 15 and nuts 9. Therefore, thrust color 5
Rotates together with the pump main shaft 1.

The thrust bearing 4b is formed in a ring shape and is fixed inside the casing cover 6.
The thrust bearing 4b slides on the left surface of the thrust collar 5 so as to receive the left thrust force of the pump main shaft 1. On the other hand, the thrust bearing 4c is formed in a ring shape, and is fixed to the outside of the flange 8 of the back metal 4a0. The thrust bearing 4c slides on the right surface of the thrust collar 5 so as to receive the right thrust force of the pump main shaft 1. Thus, the thrust bearings 4b, 4c
Are arranged on both sides of the thrust collar 5 and are located outside the radial bearing 4a. Also, the thrust bearings 4b, 4c
Is a tapered land bearing having a tapered portion formed on the sliding surface. The number, width, and the like of the tapered portions are set according to the magnitude of the thrust load. Since the thrust bearing 4b is fixed to the casing cover 6, the gap in the thrust direction can be easily adjusted.

The thrust bearings 4b, 4c are
As shown in the figure, the sliding surfaces are made of thermoplastic resin materials 4b2, 4c2.
More specifically, sintered filters 4b1 and 4c1 (materials: SUS316, S) are provided on back metals 4b0 and 4c0 (materials: corrosion-resistant materials such as SUS316 and SUS304).
(A corrosion-resistant material such as US304) is joined by nickel brazing or the like, and thermoplastic resin materials 4b2 and 4c2 are attached to the surface of the joined sintered filter 4a1.

The space in the casing cover 6 in which the thrust bearings 4b and 4c are arranged is communicated with a water passage in the pump casing 3 through a groove 12 formed in the radial bearing 4a to supply pumped water. Casing cover 6
An air vent 11 is provided on the upper surface of the casing cover 6 so that no air bubbles remain in the internal space. This air vent 1
1 is opened when the pumping water before starting is full, and closed when the pumping water is full. The pumped water having passed through the groove 12 is guided to the thrust bearings 4b and 4c to perform lubrication.

In the double suction centrifugal pump according to the present embodiment, since pumping water is used as a lubricant for all the bearings 4a, 4b and 4c, the lubricating oil and grease conventionally used are not required, and the maintenance is not required. It is possible to realize a pump which is free from environmental problems and can eliminate environmental pollution caused by leakage of lubricating oil and grease.

Further, since the radial bearings 4a supporting both sides of the pump main shaft 1 are held by the water passage portion of the pump casing 3, the bearings are supported as compared with a conventional bearing supported at a position away from the pump casing. Thus, the span between the two radial bearings 4a can be reduced, thereby increasing the bearing support rigidity. As a result, the vibration at the time of high-speed rotation of the pump can be reduced, and the size and speed of the pump can be reduced and the efficiency of the pump can be improved.

Further, the sliding portions of the radial bearings 4a and the thrust bearings 4b, 4c are made of thermoplastic resin materials 4a2, 4a.
Since it is formed of b2 and 4c2, there is almost no change in shape due to swelling like a conventional thermosetting resin (for example, phenol resin) under water lubrication using water pumping, and it is stable and low up to a high load region. A friction coefficient is obtained, and the initial bearing sliding surface shape can be maintained for a long period of time. Thereby, reliability for long-term operation is significantly improved. Also, both radial bearings 4a and thrust bearings 4b,
Thermoplastic resin material 4a2, 4b forming the sliding portion 4c
2, 4c2 shows that even in a high load region, even if a water film break occurs locally due to one-sided contact with the pump main shaft 1, the sliding surface is softened, the flow easily occurs, and the smoothing proceeds. It is stabilized while being adjusted to the pump main shaft 1 and the thrust collar 5. Thus, the thermoplastic resin materials 4a2, 4b
Since the 2, 4c2 flows easily when it comes into local contact, damage to the main shaft side and the thrust cover side can be prevented. Therefore, stable pump performance can be maintained, and high reliability is ensured for a long period.

Thermoplastic resin materials 4a2, 4b
In order to confirm the effect of using 2, 4c2, sliding element tests were performed on various materials using a combination of a ring-shaped rotating side material and a ring-shaped fixed side material, and the critical surface pressure and damage to the sliding surface were examined. . The operating conditions were as follows: six radiation grooves for water lubrication were formed on the fixed-side material, and water was allowed to flow through the grooves to lubricate the sliding surface, while the peripheral speed was constant at 5 m / s, and the friction coefficient began to rise sharply. Rotate the rotating material for about 30 minutes at the surface pressure (limit surface pressure).

Table 1 shows the results of the sliding element test.

[0029]

[Table 1] As is clear from Table 1, extremely high critical surface pressure of 5 MPa or more was obtained by using PEEK-based resin in water lubrication and combining with double-layer stainless steel and cemented carbide. It was confirmed that there was no rotation-side damage or fixed-side damage. In particular, cemented carbide coatings and PE
In the combination with the EK resin, the test piece No. 2
As is clear from the above, an extremely high critical surface pressure of 7 MPa (a critical surface pressure that is 40% higher than the critical surface pressure of 5 MPa due to the combination of the double-layer stainless steel and PEEK-based resin of test piece No. 1) was obtained. Was done. The double-layer stainless steel had a Vickers hardness of 600 or more, and the cemented carbide coating used was a nickel binder cemented carbide having corrosion resistance.

Further, the thermoplastic resin materials 4a2, 4b2, 4
By mixing carbon fibers with the PEEK resin forming c2, the thermoplastic resin materials 4a2, 4b2, 4c
It was found that, while the mechanical strength of No. 2 was improved, the carbon fiber portion became a water reservoir and a markedly superior lubricating effect was exhibited.

FIG. 4 shows a second embodiment of the present invention. This embodiment is different from the above-described first embodiment in the following points.

In this embodiment, a sleeve 13 having a corrosion-resistant cemented carbide film 13a on the sliding surface is fixed to the pump main shaft 1, and a corrosion-resistant cemented carbide film 13b is provided on both sliding surfaces of the thrust collar 5. It differs from the first embodiment in that it is covered. This sleeve 13 is made of SUS304
And is slightly longer than the radial bearing 4a at the position where the radial bearing 4a is located, and is prevented from rotating (not shown).
To the pump main shaft 1. The surface of the sleeve 13 is coated with a corrosion-resistant cemented carbide film 13a.

According to this embodiment, the surface 13a of the sleeve
In the event that the shaft is damaged, only the sleeve 13 needs to be replaced, and the replacement cost can be reduced as compared with the case where the spindle itself is replaced. Further, as is apparent from Table 1, since the surfaces of the sleeve 13 and the thrust collar 5 are coated with the corrosion-resistant cemented carbide coatings 13a and 13b, they are hardly damaged and the surface is hardly deformed, so that the load resistance is increased. Sex is greatly improved. And because it is a combination of a cemented carbide and a thermoplastic resin, the conformability is good,
The roughness of the sliding surfaces of the sleeve 13 and the bearing 4a is small and smooth. Therefore, the formation of the water film becomes good immediately after the start-up, and the load resistance is improved. In this embodiment, the case where the cemented carbide film is applied to a corrosion resistant metal (such as SUS304) has been described.
A cemented carbide solid may be used instead of 3b. The material of the cemented carbide is preferably a nickel binder-based cemented carbide having corrosion resistance.

FIG. 5 shows a third embodiment of the present invention. This embodiment is different from the above-described first embodiment in the following points.

In this embodiment, the thrust collar 5 is directly fitted into and fixed to the groove at the end of the pump main shaft 1, and the end face of the radial bearing 4a made of only thermoplastic resin is slidable on the thrust collar 5. This is different from the first embodiment in that According to the present embodiment, the radial bearing 4a
However, since it also serves as a thrust bearing, the structure can be made simple and inexpensive.

FIG. 6 shows a fourth embodiment of the present invention. This embodiment is different from the above-described third embodiment in the following points.

This embodiment is a horizontal shaft drainage pump, in which one radial bearing 4a is installed in a pump casing 3, and the other radial bearing 4a is attached to a side surface portion of the pump casing 3 on the other end side of the pump main shaft 1. And thrust bearings 4b, 4
The third embodiment differs from the third embodiment in that c is provided. In this horizontal shaft drain pump, the blade 2 is fixed to the pump main shaft 1,
A pump casing 3 is provided so as to surround the outer periphery of the blade 2, a radial bearing 4 a is installed in the pump casing 3, and the remaining radial bearing 4 a and thrust bearing 4
b and 4c are fixed to the pump casing 3 side. Further, a pipe 14 for using pumping water is connected to the discharge side of the bearings 4a, 4b, 4c on the pump casing 3 side. That is, one side of the other radial bearing 4a communicates with the suction side passage of the pump casing 3, and the other side of the radial bearing 4a and the thrust bearings 4b, 4b
The discharge side passage of the pump casing 3 is communicated with c.
In the case of this type of pump, the bearings 4a, 4b, 4c provided on the pump casing 3 side are in a negative pressure state during normal operation, and no pumping water is supplied.
To supply water between the thrust bearing 4b and the seal 7. At the time of operation, the pump casing 3 is filled with pumping water before starting, and after filling, the pump casing 3 starts and starts drainage operation.

In this embodiment, since pumped water can be reliably supplied to the bearings 4a, 4b, 4c provided on the pump casing side, direct lubrication by pumping can be performed similarly to the above-described double suction centrifugal pump. A stable horizontal axis drainage pump can be obtained while maintaining stable performance for a period.

[0039]

According to the present invention, it is possible to obtain a highly reliable horizontal shaft type pump which can be operated stably for a long time without maintenance and can prevent damage due to a partial contact of the radial bearing.

Further, according to the present invention, it is possible to obtain a horizontal shaft type pump which is maintenance-free and which can reduce vibration at the time of high-speed rotation and can reduce the size and speed of the pump and improve the efficiency.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a double suction centrifugal pump showing a first embodiment of the present invention.

FIG. 2 is an enlarged view of a bearing portion on one side of the double suction centrifugal pump in FIG. 1;

FIG. 3 is an enlarged view of a bearing part on the other side of the double-suction volute pump of FIG. 1;

FIG. 4 is a longitudinal sectional view of a bearing portion of a double-suction volute pump according to a second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a double suction centrifugal pump showing a third embodiment of the present invention.

FIG. 6 is a longitudinal sectional view of a horizontal axis drainage pump showing a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pump main shaft, 2 ... Blade, 3 ... Pump casing, 3
a: bearing support, 4a: radial bearing, 4a0: back metal,
4a1: sintered filter, 4a2: thermoplastic resin material, 4
b, 4c: thrust bearing, 4b0, 4c0: back metal, 4b
1, 4c1 ... sintered filter, 4c2, 4c2 ... thermoplastic resin material, 5 ... thrust collar, 6 ... casing cover, 7 ... seal, 8 ... collar, 9 ... nut, 12 ... groove,
13: sleeve, 13a, 13b: cemented carbide film, 15
... bolt, 16 ... coupling part, 17 ... casing cover.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16C 17/10 F16C 17/10 Z 33/10 33/10 Z 33/20 33/20 Z (72) Invention Tomoaki Inoue 502 Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Shigenobu Nagasawa 603, Kachimachi-cho, Tsuchiura-shi, Ibaraki Pref. Industrial Machinery Systems Division, Hitachi Ltd. Hideki 603 Kandamachi, Tsuchiura-shi, Ibaraki Pref. AA06 BA02 BA08 JA02 KA02 KA03 MA02 QA05 SC16

Claims (7)

[Claims] A pump main shaft to which a blade is fixed; a pump casing surrounding a periphery of the blade to form a water passage; and a bearing for supporting the pump main shaft on both sides of a portion to which the blade is fixed. In the horizontal shaft type pump, one of the bearings is formed of a radial bearing made of a sliding bearing, and the other bearing is formed of a radial bearing made of a sliding bearing and a thrust bearing juxtaposed thereto. A horizontal shaft type pump wherein a sliding portion of a bearing is formed of a thermoplastic resin, and pumping water is used as a lubricant for all the bearings. 2. A pump main shaft to which blades are fixed, a pump casing surrounding a periphery of the blades to form a water passage, and a bearing for supporting the pump main shaft on both sides of a portion to which the blades are fixed. In the horizontal shaft type pump, one of the bearings is formed of a radial bearing made of a sliding bearing, and the other bearing is formed of a radial bearing made of a sliding bearing and a thrust bearing juxtaposed thereto. A horizontal shaft type pump wherein a bearing and a sliding portion of the thrust bearing are formed of a thermoplastic resin, and pumping water is used as a lubricant for all the bearings. 3. The horizontal shaft type pump according to claim 1, wherein a sliding portion of said bearing is formed of a polyetheretherketone resin. 4. The sliding part of the bearing according to claim 1, wherein the thermoplastic resin forming the sliding part of the bearing is a polyetheretherketone resin, and the sliding part of the pump main shaft is made of a nickel-binder type super hard material having corrosion resistance. A horizontal shaft type pump formed of an alloy. 5. A pump main shaft to which a blade is fixed, a pump casing surrounding a periphery of the blade to form a water passage, and a bearing for supporting the pump main shaft on both sides of a portion to which the blade is fixed. In the horizontal shaft type pump, the one side bearing is formed by a radial bearing, the other side bearing is formed by a radial bearing and a thrust bearing juxtaposed thereto, and the other side radial bearing is formed by the pump casing. A horizontal shaft type pump, wherein the pump is held in a water passage portion and pumping water is used as a lubricant for all the bearings. 6. The pump casing according to claim 5, wherein one side of the other radial bearing communicates with a suction-side passage of the pump casing, and the other side of the radial bearing and the thrust bearing are connected to the pump casing. A horizontal shaft type pump characterized by communicating with a discharge side passage. 7. A pump main shaft to which a blade is fixed, a pump casing surrounding a periphery of the blade to form a water passage, and a bearing for supporting the pump main shaft on both sides of a portion to which the blade is fixed. In the horizontal shaft type pump, one of the bearings is formed of a radial bearing made of a sliding bearing, and the other bearing is formed of a radial bearing made of a sliding bearing and a thrust bearing juxtaposed thereto. The sliding portion of the bearing is formed of a thermoplastic resin, the other radial bearing is held by a side surface portion of the pump casing facing the water passage, and pump water is used as a lubricant for all the bearings. A horizontal shaft type pump characterized by the above-mentioned.