JP2003294028A - Underwater bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an underwater bearing capable of optionally controlling a gap between a top end of a sliding body and a shaft in case that swelling caused by water absorption and heat expansion caused by a change of temperature are generated on the sliding body. <P>SOLUTION: The underwater bearing is installed on an inner periphery of a shell 21 at intervals to a peripheral direction, and is provided with a plurality of segment-shaped sliding bodies 22 projecting to a shaft 11 from the inner periphery of the shell 21. A pair of groove walls of an installing groove 23 are set to be tapered walls 23e and 23f. A side face of a base portion 22a of the sliding body 22 corresponding to the tapered walls 23e and 23f is set to be tapered faces 22d and 22e. An elastic body 24 makes the tapered faces 22d and 22e connected with the tapered walls 23e and 23f by elastically urging the sliding body 22 toward the shaft 11, and is arranged between the sliding body 22 and installing groove 23. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-lubricating submersible bearing suitable for, for example, a submersible pump bearing.

[0002]

14 and 15 show a conventional self-fluid lubrication type underwater bearing. The submersible bearing 1 shown in FIG.
A cylindrical slide body 3 attached to the inner peripheral surface of the shell 2 is provided, and a plurality of grooves 3a extending in the axial direction of the shaft 4 are provided in the slide body 3 at intervals in the circumferential direction. On the other hand, the submersible bearing 5 shown in FIG. 15 includes a plurality of segment-shaped sliding bodies 7 that are attached to the inner peripheral surface of the shell 6 at intervals in the circumferential direction and project toward the shaft 4.

[0003]

In the underwater bearing 1 shown in FIG. 14, when the sliding body 3 swells due to water absorption or expands due to temperature rise (thermal expansion), the inner diameter of the sliding body 3 decreases as indicated by the dotted line. The gap with the shaft 4 becomes narrower. Similarly, in the underwater bearing 5 of FIG. 15, when the sliding body 7 swells or thermally expands, the top end surface 7a of the sliding body 7 is displaced toward the shaft 4 side and the gap between the two is narrowed. Therefore, when the submersible bearings 1 and 5 are used as bearings for supporting the shaft of the submersible pump, the shaft 4 is fixed (locked) due to swelling or thermal expansion of the sliding bodies 3 and 7 during standby, and thus the starting is impossible. There is a risk that In addition, while operating the submersible pump,
If the contact between the shaft 4 and the shaft 4 occurs, the submersible pump may be inoperable due to baking. Therefore, these submerged bearings 1 and 5 could not be used as bearings for submersible pumps. As described above, the gap between the top end surface of the sliding body and the shaft at the time of expansion is an important factor that determines the application range of the underwater bearing and the like.

Therefore, the present invention provides an underwater bearing capable of arbitrarily controlling the gap between the top end face of the sliding body and the shaft when the sliding body swells due to water absorption or thermal expansion due to temperature rise. Is an issue.

[0005]

In order to solve the above-mentioned problems, the present invention relates to a cylindrical shell through which a shaft penetrates and is attached to the inner peripheral surface of this shell at intervals in the circumferential direction,
A plurality of segment-shaped sliding bodies that respectively project from the inner peripheral surface of the shell toward the shaft, which is a submersible bearing, wherein the inner peripheral surface of the shell has a plurality of shafts that respectively hold the sliding bodies. Mounting grooves extending in the circumferential direction are provided at intervals in the circumferential direction, and a pair of groove walls facing each other of the mounting grooves form the same angle with respect to the inner peripheral surface of the shell from the bottom wall of the mounting groove to the opening. Is a taper wall whose interval is reduced at a constant rate toward the shaft, the sliding body protruding from the inner peripheral surface of the shell toward the shaft, and the top end surface of the sliding body. A pair of side surfaces of the base, which face each other and which correspond to the taper wall of the mounting groove, are formed such that the tapered wall is inside the shell. Angle to the circumference The sliding surface is a tapered surface that has the same angle and has a constant reduction in distance from the bottom wall of the mounting groove toward the opening, and between the bottom surface of the sliding body and the bottom wall of the mounting groove. An underwater bearing is provided in which an elastic body that elastically urges the moving body toward the shaft and presses the tapered surface of the base portion of the sliding body against the tapered wall of the mounting groove is arranged.

In the submersible bearing of the present invention, the pair of tapered walls of the mounting groove provided in the shell and the corresponding pair of tapered surfaces of the base portion of the sliding body form the same angle with the inner peripheral surface of the shell. The distance between the tapered wall and the tapered surface decreases from the bottom wall of the mounting groove toward the opening. That is, the cross-sectional shapes of the mounting groove and the base of the sliding body are trapezoidal shapes that are similar to each other. Further, the sliding body is biased by the elastic body, so that the tapered surface is pressed against the tapered wall. Therefore, when the sliding body expands due to swelling due to water absorption or thermal expansion due to temperature change, the entire sliding body is displaced toward the bottom wall of the mounting groove while compressing the elastic body. Since the displacement of the sliding body can be adjusted by the angle that the tapered wall and tapered surface form with the inner peripheral surface of the shell, the clearance between the top end surface of the sliding body and the shaft during expansion can be controlled by setting this angle. can do.

Further, since the sliding body is urged by the elastic body, when a foreign substance is caught in the gap between the top end surface of the sliding body and the shaft, or the shaft is abutted against the shaft, the shaft is moved toward the top end surface of the sliding body. When it collides with, the sliding body is displaced toward the bottom wall of the mounting groove while compressing the elastic body. Therefore, it is possible to prevent the sliding body from being damaged due to the foreign matter being caught or the uneven contact.

For example, in the mounting groove, a pair of side walls facing each other in the circumferential direction are the tapered walls, and in a base portion of the sliding body, a pair of side surfaces facing each other in the circumferential direction are the tapered surfaces. Alternatively, the mounting groove may have a pair of axially opposed end walls that are tapered walls, and the base of the sliding body may have a pair of axially opposed end surfaces that are tapered surfaces.

The angles of the tapered wall and the tapered surface with respect to the inner peripheral surface of the shell are set so that the position of the top end surface of the sliding body is maintained even if the sliding body expands. Specifically, when the expansion of the sliding body is isotropic, the angle of the tapered wall and the tapered surface with respect to the inner peripheral surface of the shell is determined by the intersection of the tapered wall and the tapered surface when the sliding body is not expanded. Is set so as to coincide with the top end surface.

The angles of the tapered wall and the tapered surface with respect to the inner peripheral surface of the shell may be set so that the top end surface of the sliding body is displaced toward the inner peripheral surface of the shell due to expansion of the sliding body. Good. Specifically, when the expansion of the sliding body is isotropic, the angle of the tapered wall and the tapered surface with respect to the inner peripheral surface of the shell is determined by the intersection of the tapered wall and the tapered surface when the sliding body is not expanded. Is set to be closer to the shaft than the top end surface.

For example, the elastic body is an elastic resin filled between the bottom surface of the sliding body and the bottom wall of the mounting groove. By providing a cavity in the elastic resin, it is possible to adjust the elastic force by which the elastic resin urges the sliding body toward the shaft. That is, by increasing the ratio of the volume of the cavity to the total volume of the elastic resin, it is possible to reduce the elastic biasing force to the sliding body. The elastic body may be a coil spring or a leaf spring.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention shown in the drawings will be described in detail. FIG. 1 is a self-lubricating type submersible bearing 10A, 10B, 10 according to a first embodiment of the present invention.
Figure 3 shows a vertical submersible pump with C. 3 of the same structure
Of the submersible bearings 10A to 10C, two submersible bearings 10A and 10B that support the lower end side of the shaft 11 are housed in the same bearing casing 12A, and the remaining one submersible bearing that supports the vicinity of the center of the shaft 11 is underwater. The bearing 10C is independently housed in the bearing casing 12B. The shaft 11 is supported above the impeller 13 by the two underwater bearings 10A and 10B. Since the load due to the impeller fluid force is the largest at this portion, the supported portion of the shaft 11 is set to be long. It is necessary.

As shown in FIGS. 2 to 4, the bearing casing 12A for holding the two submerged bearings 10A, 10B has a cylindrical shape with openings at both ends and is provided with a screw hole 12a for fixing to the vane casing 16. A flange portion 12b is provided at one end thereof. Further, the peripheral wall of the bearing casing 12A is provided with screw holes 12c for positioning the submersible bearings 10A and 10B. Further, annular end plates 17A and 17B for holding the submersible bearings 10A and 10B inside are attached to both ends of the bearing casing 12. The bearing casing 12B that holds the remaining one submerged bearing 10C has the same structure.

Since the three submerged bearings 10A to 10C have the same structure, the submerged bearing 10A will be described below. As shown in FIGS. 2 and 3, the submersible bearing 10A includes a cylindrical shell 21 through which the shaft 11 of the vertical submersible pump penetrates, and a plurality of segment-shaped sliding bodies attached to the inner peripheral surface side of the shell 21. 22 and 22. The shell 21 is made of, for example, stainless steel, copper alloy, synthetic resin or the like. The sliding body 22 is made of, for example, a thermosetting resin such as a phenol resin, a synthetic resin that causes a swelling phenomenon due to water absorption, or a thermoplastic resin, a PBI resin, or a metal material in which the swelling phenomenon can be ignored but the thermal expansion is relatively remarkable. Consists of.

As shown in FIGS. 2 and 6, a plurality of mounting grooves 23 for holding the sliding body 22 are provided on the inner peripheral surface side of the shell 21. The mounting grooves 23 extend parallel to the shaft 11, that is, in the axial direction, and are provided at regular intervals in the circumferential direction. In this embodiment, the shell 21
There are 14 mounting grooves 23 provided in the.

As shown in FIG. 6B, each mounting groove 23 penetrates the shell 21 in the axial direction, and both ends thereof are open ends 23.
a and 23b. Further, as shown in FIGS. 2, 5 and 6, the mounting groove 23 is formed in the opening 23 on the inner peripheral surface side of the shell 21.
It has a bottom wall 23d facing c and a pair of side walls 23e, 23f facing each other in the circumferential direction. The side wall 23e,
23f includes a first portion 23g, a second portion 23h, and a third portion 23i from the opening 23c side toward the bottom wall 23d side.

The first portions 23g of the side walls 23e and 23f are flat and form the same angle δ with the inner peripheral surface of the shell 21. This angle δ is an acute angle and the side walls 23e, 2
The first portion 23g of 3f has an opening 23a from the bottom wall 23d side.
The taper wall has a constant reduction in distance toward the side. Therefore, the mounting groove 23 is a dovetail groove having a substantially trapezoidal cross section in the direction orthogonal to the longitudinal direction (axial direction). In the second portion 23h, the distance between the side walls 23e and 23f is substantially constant, and in the third portion 23i, the side walls 23e and 23f.
The space between 3f is enlarged toward the opening 23c side.

A screw hole 21a for fixing to the bearing casing 12A is provided on the outer peripheral surface side of the shell 21. An injection hole 21b reaching the bottom wall 23d from the outer peripheral surface of the shell 21 is provided for each mounting groove 23.

As shown in FIGS. 2, 3, 5, and 7,
The sliding body 22 includes a base portion 22a arranged in the mounting groove 23,
From the inner peripheral surface of the shell 21 through the opening 23c to the shaft 1
1 is provided. The base portion 22a has an isosceles triangular shape, and has a bottom surface 22c that is slightly convexly curved toward the opening 23c and a pair of side surfaces 22.
d and 22e.

The side surfaces 22d and 22e of the base portion 22a are flat surfaces and form the same angle with the inner peripheral surface of the shell 21, and have a constant ratio from the bottom wall 23d side of the mounting groove 23 toward the opening 23c side. The taper surface reduces the space. The angle formed by each side surface 22d, 22e with respect to the inner peripheral surface of the shell 21 is the same as the angle δ formed by the first portions 23g of the side walls 23e, 23f of the mounting groove 23 with respect to the inner peripheral surface of the shell 21. . Therefore, the cross section of the base portion 22a perpendicular to the longitudinal direction is a trapezoid similar to the trapezoid formed by the cross section of the first portions 23g of the side walls 23e and 23f of the mounting groove 23.

Both ends of the mounting groove 23 are open ends 23a and 23b.
Therefore, as shown in FIG. 2, the end faces 22f and 22g of the sliding body 22 are open. Therefore, the sliding body 22
Is not constrained from being deformed in the axial direction, the end faces 22f, 22
g can be freely displaced in the axial direction.

The protruding portion 22b of the sliding member 22 has an inverted triangular shape, and is formed with a pair of reverse tapered side surfaces 22h and 22i whose distance increases toward the shaft 11 side and a side circumferential surface of the shaft 11 with a gap therebetween. And a top end face 22j facing each other. On the bottom surface 22c of the sliding body 22, a hemispherical recess 22k is provided at a position corresponding to the injection hole 21b of the shell 21.

As shown in FIG. 2, FIG. 3, and FIG.
Between the bottom surface 22c of 2 and the bottom wall 23d of the mounting groove 23,
The elastic resin 24 is filled. The sliding member 22 is elastically biased toward the shaft 11 by the elastic resin 24. This biasing force causes the sliding member 22 to be a tapered surface.
The side surfaces 22d and 22e of the base portion 22a are elastically pressed against the first portions 23g of the side walls 23e and 23f of the mounting groove 23, which are tapered walls. As mentioned above, the first portion 23g
At the side walls 23e and 23f of the mounting groove 23,
Angle with respect to the inner peripheral surface of the base 22a of the sliding body 22
The angles formed by the side surfaces 22d and 22e of the above with respect to the inner peripheral surface of the shell 21 are the same angle δ. Therefore, the side surfaces 22 d and 22 e of the base portion 22 a of the sliding body 22 are attached to the side wall 2 of the mounting groove 23.
It is in close contact with the first portion 23g of 3e and 23f. Also,
When the base portion 22a of the sliding body 22 is locked to the first portions 23g of the side walls 23e and 23f of the mounting groove 23, the opening 2
The sliding body 22 is prevented from coming off from 3c.

The elastic resin 24 has one of the open ends 2
After the base portion 22a of the sliding body 22 is inserted from 3a and 23b and arranged in the mounting groove 23, the molten elastic resin is injected from the injection hole 21b formed in the shell 21 to fill the sliding member 22. The elastic resin 24 is the bottom wall 23d of the mounting groove 23.
Not only the space between the bottom surface 22c of the slide body 22 and the bottom surface 22c of the slide body 22, but also the recess 22k and the injection hole 21b provided in the bottom surface 22c of the slide body 22 are filled. Therefore, the elastic resin 24 restricts the movement of the sliding body 22 in the axial direction, and the sliding body 22 is prevented from coming off from the opening ends 23a and 23b of the mounting groove 23.

The elastic resin 24 is provided with a plurality of cavities 25 extending in the axial direction. In these cavities 25, a plurality of elongated rod members are previously arranged in the mounting groove 23 in advance when the above-mentioned molten elastic resin is injected, and after the elastic resin is cured, these rod members are opened end 23a of the mounting groove 23, It is formed by pulling out from one side of 23b. The cavity 25 allows the elastic force of the elastic resin 24 to urge the sliding body 22 toward the shaft 11 side to be adjusted. That is, the urging force can be reduced by increasing the ratio of the volume of the cavity 25 to the total volume of the elastic resin 24.

The above-mentioned angle δ, that is, the side walls 23e and 23f of the mounting groove 23 have the shell 2 at the first portion 23g.
Angle formed with respect to the inner peripheral surface of the sliding member 22 and the base portion 22 of the sliding body 22
By appropriately setting the angle formed by the side surfaces 22d and 22e of a with respect to the inner peripheral surface of the shell 21, the position of the top end surface 22j when the sliding body 22 expands due to swelling due to water absorption or thermal expansion due to temperature change Can be controlled. Hereinafter, this point will be described in detail with reference to FIGS. 8 to 10. 8 to 10, the sectional shapes of the sliding body 22 and the mounting groove 23 are shown in a simplified manner in order to clarify the shape change before and after the expansion. Further, in these drawings, the shape of the sliding body 22 before expansion is shown by a thick solid line,
The shape of the sliding body 22 after expansion is shown by a dotted line. Further, in these drawings, T is the circumferential dimension of the sliding body 22 before expansion, T + Δt is the circumferential dimension of the sliding body 22 after expansion, Δt is the expansion in the circumferential direction of the sliding body 22 due to expansion, L is the radial dimension of the sliding body 22 before expansion, H is the radial dimension of the protrusion 22b before expansion, H + Δh is the radial dimension of the protrusion 22b after expansion, and Δh is the protrusion 22b due to expansion. The radial elongation of each is shown.

As described above, the side surfaces 22d and 22e of the base portion 22a of the sliding body 22 and the side walls 23e and 23 of the mounting groove 23 are provided.
The angles δ formed by f (the first portion 23g) and the inner peripheral surface of the shell 21 are the same. Further, since the sliding body 22 is biased by the elastic resin 24, the side surfaces 22d and 22e of the base portion 22a of the sliding body 22 which is a tapered surface are formed into side walls 23e and 23f (first portion) of the mounting groove 23 which is a tapered wall. Two
3g) pressed against each other. Therefore, when the sliding body 22 expands, the entire sliding body 22 is displaced toward the bottom wall 23d of the mounting groove 23 while compressing the elastic resin 24.
In other words, when the sliding body 22 expands, it is drawn into the mounting groove 23 by a kind of wedge effect. This sliding body 22
The displacement amount toward the entire bottom wall 23d, that is, the displacement amount Δr in the radial direction of the sliding body 22 due to the expansion is enlarged and shown in FIGS. 8 (B), 9 (B), and 10 (B). Thus, it is represented by the following equation (1).

[0028]

[Equation 1]

The position of the top end surface 22j after expansion is determined by the magnitude relation between the displacement amount Δr of the entire sliding body 22 expressed by the above equation (1) and the radial expansion Δh of the protrusion 22b. Specifically, as shown in FIG. 8, when the displacement amount Δr is equal to the elongation Δh, the position of the top end face 22j is maintained even after the expansion, and the gap S between the top end face 22j and the shaft 11 does not change before and after the expansion. . Further, as shown in FIG. 9, when the displacement amount Δr is larger than the elongation Δh, the top end face 22j after expansion is displaced radially outward, that is, toward the bottom wall 23d of the mounting groove 23, and due to expansion. The gap S expands. Furthermore, FIG.
As shown in 0, when the displacement amount Δr is smaller than the elongation Δh, the expanded top end face 22j is displaced inward in the radial direction, that is, toward the shaft 11, and the expansion causes the top end face 22j.
The gap S between j and the shaft 11 is reduced.

The magnitude relationship between the displacement amount Δr and the elongation Δh is as follows:
It is determined by the angle δ according to the shape of the sliding body 22. In particular,
If the radial dimension H of the protrusion 22b is the same, the magnitude relationship between the displacement amount Δr and the elongation Δh is determined only by the angle δ. Further, even if the expansion of the sliding body 22 has anisotropy, that is, even if the expansion coefficient of swelling or thermal expansion of the sliding body 22 differs depending on the direction, the angle δ that realizes the three types of magnitude relationship is determined. .

When the expansion of the sliding body 22 is isotropic,
That is, the setting of the angle δ will be described by taking as an example the case where the expansion coefficients of swelling and thermal expansion of the sliding body 22 are the same in all directions. When the expansion is isotropic, if the elongation rate due to one or both of swelling and thermal expansion is β,
The following expressions (2) and (3) are established.

[0032]

[Equation 2]

As shown in FIG. 8, when the sliding body 22 is not expanded, the sliding body 2 is located at the intersection a of the side walls 23e and 23f which are tapered walls and the side surfaces 22d and 22e of the base portion 22a which is a tapered surface.
When the angle δ is set so as to match the top end face 22j of No. 2, the position of the top end face 22j is maintained before and after the expansion, and the gap S does not change.

In this case, the intersection a from the inner peripheral surface of the shell 21
The height A up to and the radial dimension H of the protrusion 22b before expansion are equal (A = H).

Further, the height A from the inner peripheral surface of the shell 21 to the intersection a is expressed by the following equation (4) from the geometrical relation.

[0036]

[Equation 3]

By substituting the equation (2) into the equation (1), the following equation (5) is obtained.

[0038]

[Equation 4]

On the other hand, when A = H is applied to the equation (3) and the equation (4) is substituted, the following equation (6) is obtained.

[0040]

[Equation 5]

From equations (5) and (6), it can be seen that Δr and Δh are equal and the position of the top end face 22j does not change.

Next, as shown in FIG. 9, when the sliding body 22 is not inflated, an angle δ is set so that the intersection point a is located on the shaft 11 side, that is, the radial inner side with respect to the top end surface 22j of the sliding body 22. When set, the top end face 22j is the sliding body 2
The expansion of 2 causes the shell 21 to be displaced toward the inner peripheral surface, that is, outward in the radial direction, whereby the gap S is enlarged.

In this case, the intersection a from the inner peripheral surface of the shell 21
The height A up to is larger than the radial dimension H of the protrusion 22b (A> H). Therefore, from the equations (3) and (4), the equation (7) holds for the elongation Δh.

[0044]

[Equation 6]

From the equations (7) and (1), it is understood that Δr> Δh, and the gap S expands when the sliding body 22 expands.

As shown in FIG. 10, when the angle δ is set so that the intersection point a is located on the shell 21 side, that is, radially outside with respect to the top end surface 22j of the sliding body 22 when the sliding body 22 is not expanded. In particular, the top end surface 22j is displaced toward the shaft 11, that is, inward in the radial direction due to the expansion of the sliding body 22, whereby the gap S is reduced.

In this case, the intersection a from the inner peripheral surface of the shell 21
The height A up to is smaller than the radial dimension H of the protrusion 22b before expansion (A <H). Therefore, equations (3) and (4)
The following expression (8) is established for more elongation Δh.

[0048]

[Equation 7]

From this equation (8) and equation (1), it can be seen that Δr <Δh, and the gap S shrinks when the sliding body 22 expands.

As described above, in this embodiment, the gap S between the top end surface 22j and the shaft 11 when the sliding body 22 is expanded can be controlled by setting the angle δ. When the angle δ is set so that the gap S is maintained during expansion as shown in FIG. 8 or when the angle δ is set so that the gap S is expanded during expansion as shown in FIG. Even if the sliding body 22 is swollen or thermally expanded, the gap S is maintained. Therefore, it is possible to reliably prevent the shaft 11 from being locked while the submersible pump is on standby, and the seizure caused by the contact between the sliding body 22 and the shaft 11 during the operation of the submersible pump.

The bottom surface 22c of the sliding member 22 and the mounting groove 2
Since the elastic resin 24 is filled between the shaft 11 and the bottom wall 23d of No. 3, when the foreign matter is caught in the gap S between the top end surface 22j of the sliding body 22 and the shaft 11, or when the shaft 11 hits one side, When the sliding body 22 collides with the top end surface 22j of the sliding body 22, the sliding body is displaced toward the bottom wall of the mounting groove while compressing the elastic body, so that the shock is mitigated. Therefore, it is possible to prevent the sliding body 22 from being damaged due to the foreign matter being caught or the one-sided contact.

Further, since each sliding body 22 is individually mounted in each mounting groove 23, it is possible to replace the damaged sliding body 22 when the submersible pump is disassembled and repaired. In this respect, the submersible pump including the submersible bearings 10A to 10C of the present embodiment is easy to maintain and the cost required therefor is reduced.

As shown in FIGS. 3 and 4, the submersible bearings 10A and 10B in the same bearing casing 12A are arranged so that their circumferential positions are displaced from each other. That is, the shaft 1
When viewed from the extending direction of No. 1, the sliding body 22 of one underwater bearing 10A is arranged so as not to overlap with the sliding body 22 of the other underwater bearing 10B as much as possible. Therefore, the supporting force can be uniformly applied to the shaft 11.

FIG. 11 shows an underwater bearing according to the second embodiment of the present invention. In the second embodiment, the mounting groove 2
3 has both ends closed. Opposing end walls 23j, 2
3k forms an angle δ with the inner peripheral surface of the shell 21, and the distance between the end walls 23j and 23k is the opening 23 from the bottom wall 23d side.
It is a tapered wall in which the interval is reduced at a constant rate toward the c side. Therefore, the mounting groove 23 is in the longitudinal direction (axial direction).
Has a substantially trapezoidal cross section. Side walls 23e, 23f
Are parallel to each other, and the circumferential dimension (width) of the mounting groove 23
Is constant.

End faces 22f, 2 of the base 22a of the sliding body 22
2g forms the same angle δ with the inner peripheral surface of the shell 22 as the end walls 23j and 23k of the mounting groove 23, and has a constant ratio from the bottom wall 23d side of the mounting groove 23 toward the opening 23c side. The interval is shrinking. On the other hand, the side surface 2 of the base 22a
2d and 22e are parallel to each other, and the size (width) of the sliding body 22 in the circumferential direction is constant. Further, the protruding portion 22b of the sliding body 22 has a shape continuous with the base portion 22a, and the end surface 22
The distances f and 22g are reduced toward the top end surface 22j, and the side surfaces 22h and 22i are parallel to each other. The side surfaces 22d and 22e of the base portion 22a of the sliding body 22 are the bottom surface 22 of the sliding body 22.
The elastic resin 24 filled between c and the bottom wall 23d of the mounting groove 23 elastically urges the shaft 11 toward the shaft 11. Due to this biasing force, the end surfaces 22f and 22g of the base portion 22a of the sliding body 22 which is a tapered surface are pressed against the end wall portions 23j and 23k of the mounting groove 23 which is a tapered wall. First
Similar to the embodiment, the sliding body 22 is set by setting the angle δ.
It is possible to control the gap S between the top end surface 22j and the shaft 11 at the time of expansion.

Since the other structure and operation of the second embodiment are the same as those of the first embodiment, the same elements are designated by the same reference numerals and the description thereof will be omitted.

FIG. 12 shows an example in which a coil spring 26 is used as an elastic body for supporting the sliding body 22 in place of elastic resin. Further, FIG. 13 shows an example in which a leaf spring 27 is used as an elastic body that supports the sliding body 22. The elastic body that supports the sliding body 22 can elastically bring the tapered surface of the sliding body 22 into contact with the tapered wall of the mounting groove 23 with a certain biasing force, and the swelling and thermal expansion of the sliding body 22 can be performed. In this case, the bottom surface 22c of the sliding body 22 is fixed to the bottom wall 23 of the mounting groove 23.
It is sufficient if it does not hinder the displacement to the d side as much as possible.

Although the present invention has been described by taking the pump submersible bearing as an example, the present invention can be applied to other submerged bearings such as a stern screw bearing.

[0059]

As is apparent from the above description, in the submersible bearing of the present invention, the pair of tapered walls of the mounting groove provided in the shell and the pair of tapered surfaces of the base of the sliding body corresponding thereto are the shell. At the same angle with respect to the inner surface of the mounting groove, and the distance decreases from the bottom wall of the mounting groove toward the opening. That is, the cross-sectional shapes of the mounting groove and the base of the sliding body are trapezoidal shapes that are similar to each other. Further, the sliding surface is biased by the elastic body, so that the tapered surface is in contact with the tapered wall. Therefore, when the sliding body expands due to swelling due to water absorption or thermal expansion due to temperature change, the entire sliding body is displaced toward the groove wall of the mounting groove while compressing the elastic body. Since it can be adjusted by the angle formed by the tapered surface of the moving body with respect to the inner peripheral surface of the shell, the gap between the top end surface of the sliding body and the shaft during expansion is defined by the tapered wall and tapered surface with respect to the inner peripheral surface of the shell. It can be controlled by setting the tilt angle.

Further, since the sliding body is biased by the elastic body, when a foreign object is caught in the gap between the top end surface of the sliding body and the shaft, or when the foreign matter is caught by one side, the shaft top surface of the sliding body is moved. When it collides with, the sliding body is displaced toward the bottom wall of the mounting groove while compressing the elastic body. Therefore, it is possible to prevent the sliding body from being damaged due to the foreign matter being caught or the uneven contact.

[Brief description of drawings]

FIG. 1 is a sectional view showing a vertical submersible pump including a pump submersible bearing according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a pump submersible bearing according to the first embodiment of the present invention.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a partially enlarged sectional view showing a segment slide body and a mounting groove.

FIG. 6 shows a shell, (A) is a cross-sectional view, and (B) is an end view taken along line VI-VI of (A).

FIG. 7 shows a segment slide body, (A) is an end view,
(B) is a side view and (C) is a plan view.

8A and 8B show a case where the top end surface of the segment slide body coincides with a point a, FIG. 8A is a schematic sectional view showing the segment slide body before and after expansion, and FIG. 8B is an enlarged view showing a triangle αβγ in FIG. 8A. Is.

FIG. 9 shows a case where the top end surface of the segment slide body is located closer to the shaft than the point a, (A) is a schematic cross-sectional view showing the segment slide body before and after expansion, and (B) is a triangle αβγ in (A). FIG.

FIG. 10 shows a case where the top end face of the segment slide body is located closer to the shell than the point a, (A) is a schematic cross-sectional view showing the segment slide body before and after expansion, and (B) is a triangle αβγ of (A). FIG.

FIG. 11 shows an underwater bearing according to a second embodiment of the present invention, (A) is an end view, and (B) is a sectional view taken along line XI-XI of (A).

FIG. 12 is a partially enlarged cross-sectional view showing another example of an elastic body that supports a segment sliding body.

FIG. 13 is a partially enlarged cross-sectional view showing another example of an elastic body that supports a segment sliding body.

FIG. 14 shows an example of a conventional underwater bearing, (A) is an end view, and (B) is a sectional view taken along line XIV-XVI in (A).

FIG. 15 is an end view showing another example of a conventional underwater bearing.

[Explanation of symbols] [Explanation of symbols]

10A, 10B, 10C Underwater bearing 11 shaft 12A, 12B bearing casing 13 Impeller 21 shell 21a screw hole 21b injection hole 22 Sliding body 22a base 22b protrusion 22c bottom 22d, 22e Side surface (tapered surface) 22f, 22g End surface 22h, 22i side 22j Top end face 22k recess 23 mounting groove 23a, 23b Open end 23c opening 23d bottom wall 23e, 23f Side wall (tapered wall) 24 Elastic resin 25 cavities 26 coil spring 27 leaf spring

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[Procedure amendment]

[Submission date] April 3, 2002 (2002.4.3)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a sectional view showing a vertical submersible pump including a pump submersible bearing according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a pump submersible bearing according to the first embodiment of the present invention.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a partially enlarged sectional view showing a segment slide body and a mounting groove.

FIG. 6 shows a shell, (A) is a cross-sectional view, and (B) is an end view taken along line VI-VI of (A).

FIG. 7 shows a segment slide body, (A) is an end view,
(B) is a side view and (C) is a plan view.

8A and 8B show a case where the top end surface of the segment slide body coincides with a point a, FIG. 8A is a schematic sectional view showing the segment slide body before and after expansion, and FIG. 8B is an enlarged view showing a triangle αβγ in FIG. 8A. Is.

FIG. 9 shows a case where the top end surface of the segment slide body is located closer to the shaft than the point a, (A) is a schematic cross-sectional view showing the segment slide body before and after expansion, and (B) is a triangle αβγ in (A). FIG.

FIG. 10 shows a case where the top end face of the segment slide body is located closer to the shell than the point a, (A) is a schematic cross-sectional view showing the segment slide body before and after expansion, and (B) is a triangle αβγ of (A). FIG.

FIG. 11 shows an underwater bearing according to a second embodiment of the present invention, (A) is an end view, and (B) is a sectional view taken along line XI-XI of (A).

FIG. 12 is a partially enlarged cross-sectional view showing another example of an elastic body that supports a segment sliding body.

FIG. 13 is a partially enlarged cross-sectional view showing another example of an elastic body that supports a segment sliding body.

FIG. 14 shows an example of a conventional underwater bearing, (A) is an end view, and (B) is a sectional view taken along line XIV-XVI in (A).

FIG. 15 is an end view showing another example of a conventional underwater bearing.

[Explanation of symbols] 10A, 10B, 10C Underwater bearing 11 shaft 12A, 12B bearing casing 13 Impeller 21 shell 21a screw hole 21b injection hole 22 Sliding body 22a base 22b protrusion 22c bottom 22d, 22e Side surface (tapered surface) 22f, 22g End surface 22h, 22i side 22j Top end face 22k recess 23 mounting groove 23a, 23b Open end 23c opening 23d bottom wall 23e, 23f Side wall (tapered wall) 24 Elastic resin 25 cavities 26 coil spring 27 leaf spring

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3H022 AA01 BA06 CA17 CA46 CA54                       DA04 DA08                 3J011 AA03 BA13 KA01 MA12 PA03                 3J012 AB04 CB02 CB03 DB07 DB11                       EB06 FB01 GB10

Claims (11)

[Claims] 1. A cylindrical shell through which a shaft penetrates, and a plurality of segment-shaped shells that are attached to the inner peripheral surface of the shell at intervals in the circumferential direction and project from the inner peripheral surface of the shell toward the shaft. A submersible bearing comprising: a plurality of axially extending mounting grooves that respectively hold the sliding body and are provided in the inner peripheral surface of the shell at intervals in the circumferential direction. The pair of groove walls facing each other of the groove are taper walls which form an angle with the inner peripheral surface of the shell and whose intervals are reduced at a constant rate from the bottom wall of the mounting groove toward the opening. Is provided with a base portion arranged in the mounting groove, and a protrusion portion that protrudes from the inner peripheral surface of the shell toward the shaft and has a top end surface that faces the shaft at a distance. The base corresponding to the tapered wall Of the pair of side surfaces facing each other form an angle with the inner peripheral surface of the shell that is the same as the angle formed by the tapered wall with respect to the inner peripheral surface of the shell, and are directed from the bottom wall of the mounting groove toward the opening. The sliding body is a tapered surface whose interval is reduced at a constant rate, and the sliding body is elastically urged toward the shaft between the bottom surface of the sliding body and the bottom wall of the mounting groove. An underwater bearing is provided with an elastic body for pressing the tapered surface of the base portion of the base portion against the tapered wall of the mounting groove. 2. A pair of side walls facing each other in the circumferential direction of the mounting groove are the tapered walls, and a pair of side surfaces facing each other in the circumferential direction of the base of the sliding body are the tapered surfaces. The submersible bearing according to claim 1. 3. The mounting groove is characterized in that a pair of axially opposed end walls is a tapered wall, and the base of the sliding body is a pair of axially opposed end surfaces that are tapered surfaces. The submersible bearing according to Item 1. 4. The angle of the tapered wall and the tapered surface with respect to the inner peripheral surface of the shell is set so that the position of the top end surface of the sliding body is maintained even when the sliding body expands. The submersible bearing according to any one of claims 1 to 3. 5. The expansion of the sliding body is isotropic, and the angle of the tapered wall and the tapered surface with respect to the inner peripheral surface of the shell is such that the intersection of the tapered wall and the tapered surface when the sliding body is not expanded. The submersible bearing according to claim 4, wherein the underwater bearing is set so as to match the top end surface. 6. The angles of the tapered wall and the tapered surface with respect to the inner peripheral surface of the shell are set so that the top end surface of the sliding body is displaced toward the inner peripheral surface of the shell due to expansion of the sliding body. Claim 1 to Claim 3, characterized in that
The submersible bearing according to any one of 1. 7. The expansion of the sliding body is isotropic, and the angle of the tapered wall and the tapered surface with respect to the inner peripheral surface of the shell is such that the intersection of the tapered wall and the tapered surface when the sliding body is not expanded. The underwater bearing according to claim 6, wherein the underwater bearing is set so as to be located closer to the shaft than the top end surface. 8. The elastic body is an elastic resin filled between a bottom surface of the sliding body and a bottom wall of the mounting groove, and the elastic body is formed of an elastic resin. Submersible bearing according to item. 9. The underwater bearing according to claim 8, wherein the elastic resin is provided with a cavity. 10. The underwater bearing according to any one of claims 1 to 7, wherein the elastic body is a coil spring. 11. The submersible bearing according to claim 1, wherein the elastic body is a leaf spring.