JP4986909B2 - pump - Google Patents

Description

  The present invention relates to a pump in which an impeller attached to a rotating shaft and a liner ring are provided in a casing, and a minute gap is formed between the impeller and the liner ring.

  Conventionally, as this type of pump, for example, as shown in FIGS. 17 to 20, there are both suction centrifugal pumps 1. In the casing 11, there are a discharge side chamber 3 communicating with the discharge port 2, and a suction port 4. A suction side chamber 5 that communicates, an impeller 13 attached to the rotary shaft 12, and a liner ring 14 are provided, a predetermined gap 22 is formed between the impeller 13 and the liner ring 14, and the casing 11 is disposed at a lower portion. In some cases, the casing body 11a and the upper casing body (not shown) are divided into upper and lower parts.

  The liner ring 14 is fitted in a circular fitting hole 15 formed in the casing 11. Each liner ring 14 is formed in a cylindrical shape, and a waterstop ridge 16 is formed on the outer peripheral surface of the liner ring 14 over the entire circumference. Of the pair of surfaces of the water stop rod 16 orthogonal to the axis 12 a of the rotating shaft 12, the surface on the suction side chamber 5 side is a water stop surface 17.

  A water stop groove 19 is formed on the inner peripheral surface of the fitting hole 15 over the entire circumference. Of the pair of surfaces of the water stop groove 19 orthogonal to the axis 12 a, the surface on the suction side chamber 5 side is a water stop surface 20.

  According to this, by rotating the rotating shaft 12 with an electric motor or the like, the impeller 13 rotates integrally with the rotating shaft 12, water is sucked from the suction port 4, passes through the discharge side chamber 3 from both suction side chambers 5, It is discharged from the discharge port 2. At this time, the inside of the discharge side chamber 3 has a higher pressure than the inside of the suction side chamber 5, but the gap 22 between the impeller 13 and the liner ring 14 is very small. The amount of water that flows back into the side chamber 5 is reduced.

  Further, the liner ring 14 is positioned and fixed in the direction of the shaft center 12a by fitting the water stop hook 16 into the water stop groove 19. When the impeller 13 rotates and pumps water, the pressure in the discharge side chamber 3 is higher than the pressure in the suction side chamber 5, so that the pressure difference causes the liner ring 14 to move from the discharge side chamber 3 side. A pressing force is applied to the suction side chamber 5, so that the water stop surface 17 of the water stop ring 16 of the liner ring 14 comes into surface contact with the water stop surface 20 of the water stop groove 19 as shown in FIG. 19. Water can be prevented from passing through the gap S between the outer peripheral surface of the liner ring 14 and the inner peripheral surface of the fitting hole 15.

The double suction centrifugal pump having the above-described configuration is described in, for example, Patent Document 1 below.
JP2007-146789

  In the above conventional format, as shown in FIG. 19, in order to prevent water from passing through the gap S, the water stop surface 17 of the liner ring 14 is brought into surface contact with the water stop surface 20 of the water stop groove 19. Thereby, it is necessary to process both water blocking surfaces 17 and 20 with high processing accuracy, and when the processing accuracy is low, the sealing performance between both water blocking surfaces 17 and 20 is lowered. However, in order to machine both water blocking surfaces 17 and 20 with high machining accuracy, there is a problem that it takes labor.

  Further, in order to determine the position of the liner ring 14 in the radial direction A and the direction B of the axis 12a of the rotary shaft 12, as shown in FIG. Since three orthogonal surfaces 17, 23, and 24 are formed, and as shown in FIG. 20B, three surfaces 20, 25, and 26 orthogonal to each other are formed in the water stop groove 19, It took time for processing.

  Further, in Patent Document 1, in order to determine the radial position of the liner ring, a protrusion is provided in a circular insertion hole, and the inner peripheral surface of the protrusion is processed, so that the radial direction of the liner ring is determined. What determines the position is also described.

  The present invention can sufficiently secure the sealing performance between the outer peripheral surface of the liner ring and the inner peripheral surface of the fitting hole of the casing, and can easily process the liner ring and the fitting hole. The purpose is to provide a simple pump.

In order to achieve the above object, according to the first aspect of the present invention, an impeller attached to a rotating shaft and a liner ring are provided in a casing.
The casing is divided into a first casing body and a second casing body in a plane parallel to the rotation axis,
A pump in which a predetermined gap is formed between the impeller and the liner ring,
The liner ring is fitted into a fitting hole formed in the casing,
A convex part is formed on one of the outer peripheral surface of the liner ring and the inner peripheral surface of the fitting hole facing the outer peripheral surface, and on the other side, a concave part into which the convex part enters is formed.
The convex portion has a seal portion that makes line contact with the concave portion.

  According to this, the liner ring can be mounted in the casing by fitting the liner ring into the fitting hole. At this time, the seal portion of either one of the liner ring and the fitting hole makes line contact with the other recess. Thereby, the sealing performance between the outer peripheral surface of the liner ring and the inner peripheral surface of the fitting hole can be sufficiently ensured. Also, since sealing is not performed by contact between surfaces (surface contact) as in the prior art, but by line contact, processing accuracy as high as surface contact is not required, and processing of the liner ring and the insertion hole is performed. It can be done easily.

In the second invention, the convex portion is formed on the outer peripheral surface of the liner ring,
The concave portion is formed on the inner peripheral surface of the fitting hole.
In the third invention, the recess of the fitting hole is formed in an arc shape.

In the fourth invention, the convex portion of the liner ring is formed in an arc shape,
The radius of the convex part centering on the circumferential direction of the liner ring is smaller than the radius of the concave part centering on the circumferential direction of the fitting hole.

According to the fifth aspect of the invention, the convex portion is formed in a polygonal shape.
According to the sixth aspect of the present invention, a detent means for preventing the liner ring from rotating with respect to the fitting hole is provided.

  As described above, according to the present invention, when the seal portion of one of the liner ring and the fitting hole is in line contact with the other depression, the outer circumference of the liner ring and the inner circumference of the fitting hole are A sufficient sealing performance between the surfaces can be ensured. In addition, sealing is not performed by contact between surfaces (surface contact) as in the past, but is sealed by line contact, so high processing accuracy and surface area as high as surface contact are not required. Processing with the insertion hole can be easily performed.

  Furthermore, by forming the concave portion in an arc shape or forming the convex portion in an arc shape, a surface that must be formed in the concave portion or the convex portion in order to position the liner ring in the radial direction and the axial direction of the rotating shaft. The number can be reduced as compared with the prior art. Thereby, the labor of processing can be further reduced.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, reference numeral 31 denotes a double suction centrifugal pump. A suction port 33 and a discharge port 34 are formed in the casing 32. In the casing 32, a discharge side chamber 35 (vortex chamber) communicating with the discharge port 34 and suction side chambers 36 a and 36 b communicating with the suction port 33 located on the left and right sides of the discharge side chamber 35 are formed.

  A rotating shaft 38 is supported on the casing 32 by a bearing (not shown) and is sealed by a packing 39. The rotating shaft 38 is provided with left and right impellers 40 a and 40 b, and the impellers 40 a and 40 b are accommodated in the discharge side chamber 35.

  In the casing 32, a pair of left and right liner rings 41a and 41b are provided. As shown in FIGS. 3 and 4, both liner rings 41 a and 41 b are fitted in fitting holes 42 formed in the casing 32. Of these, one liner ring 41 a is disposed between one suction side chamber 36 a and the discharge side chamber 35, and the other liner ring 41 b is disposed between the other suction side chamber 36 b and the discharge side chamber 35.

  A predetermined gap 43 is formed between one impeller 40a and one liner ring 41a and between the other impeller 40b and the other liner ring 41b. As shown in FIGS. 2 and 7, the casing 32 is a parallel plane including the rotating shaft 38, and a lower casing body 32 a (an example of a first casing body) and an upper casing body 32 b (an example of a second casing body). ) And is divided. The lower casing body 32a and the upper casing body 32b are joined together by a plurality of bolts and nuts (not shown), with the joining surfaces 44a and 44b joined together through a thin packing (not shown). Thereby, the fitting hole 42 has a substantially semicircular lower fitting hole 42a (first fitting hole) formed in the lower casing body 32a and a substantially semicircular shape formed in the upper casing body 32b. It is divided into an upper fitting hole 42b (second fitting hole). The lower and upper casing bodies 32a and 32b are cast products such as cast iron and cast steel.

  As shown in FIG. 5, each of the liner rings 41 a and 41 b includes a thin cylindrical ring main body portion 46, and a convex portion 47 that is provided on the outer peripheral surface of the ring main body portion 46 and protrudes radially outward. have. The cross-sectional shape of the convex portion 47 in the radial direction A around the axis 38a of the rotation shaft 38 is formed in an arc shape.

  As shown in FIG. 4, a concave portion 49 into which the convex portion 47 enters is formed on the inner peripheral surface of each fitting hole 42, and the concave portion 49 in the radial direction A centering on the axis 38a. The cross-sectional shape is formed in an arc shape. As shown in FIG. 6, the radius r of the convex portion 47 centered in the circumferential direction of the liner rings 41a and 41b is the radius R of the concave portion 49 centered in the circumferential direction of the fitting hole 42 as shown in FIG. Smaller than. Moreover, the convex part 47 has the top part 50 (an example of a seal | sticker part) which carries out a line contact with the recessed part 49 in the circumferential direction.

The line contact mentioned here is a concept that includes not only pure geometric line contact but also line contact having a slight width due to elastic deformation and minute plastic deformation.
As shown in FIGS. 5 and 7, a detent screw 54 that protrudes radially outward from the outer peripheral surface is provided at one location of each of the liner rings 41 a and 41 b.

  Further, as shown in FIGS. 3 and 7, the lower insertion hole 42 a of the insertion hole 42 is formed with a rotation prevention hole 55 into which the rotation prevention screw 54 is fitted. The anti-rotation hole 55 is opened in the joint surface 44a of the lower casing body 32a. The anti-rotation screw 54 and the anti-rotation hole 55 constitute anti-rotation means 56.

Hereinafter, the operation of the above configuration will be described.
By rotating the rotating shaft 38 with an electric motor or the like, the impellers 40a and 40b rotate integrally with the rotating shaft 38, and water (an example of fluid) is sucked from the suction port 33, and the suction side chambers 36a and 36b discharge the discharge side chambers. It passes through 35 and is discharged from the discharge port 34. At this time, the discharge side chamber 35 has a higher pressure than the suction side chambers 36a and 36b, but the gap 43 between the impellers 40a and 40b and the liner rings 41a and 41b is very small as shown in FIG. The amount of water flowing back from the discharge side chamber 35 through the gap 43 into the suction side chambers 36a and 36b is reduced.

  Further, as shown in FIG. 7, the lower half of each liner ring 41a, 41b is fitted into the lower fitting hole 42a of the lower casing body 32a, and the anti-rotation screw 54 is fitted into the anti-rotation hole 55, thereby lower casing. By connecting the body 32a and the upper casing body 32b, the liner rings 41a and 41b are fitted into the respective fitting holes 42 and attached to the casing 32, and the anti-rotation screw 54 is attached to the anti-rotation hole 55. Fit into.

  At this time, as shown in FIG. 3, the top portions 50 of the convex portions 47 of the liner rings 41 a and 41 b are in line contact with the concave portions 49 of the fitting holes 42. Accordingly, it is possible to prevent water from passing between the outer peripheral surface of each liner ring 41a, 41b and the inner peripheral surface of each fitting hole 42, and the outer peripheral surface of each liner ring 41a, 41b and each fitting. The sealing performance between the inner peripheral surface of the hole 42 can be sufficiently ensured. Further, instead of sealing by contact between surfaces (surface contact) as in the prior art, the surface between the outer peripheral surface of the liner rings 41a and 41b and the inner peripheral surface of the fitting hole 42 is sealed by line contact. The processing accuracy as high as the contact and the width of the finished surface are not required, and the processing of the liner rings 41a and 41b and the fitting hole 42 can be easily performed.

  Further, as shown in FIG. 6, one arcuate outer peripheral surface 47a is formed on the convex part 47 of each liner ring 41a, 41b, and as shown in FIG. The liner rings 41a and 41b can be positioned in the radial direction A and the direction B of the axial center 38a only by forming one inner peripheral surface 49a, so that the labor of processing can be further reduced.

  If the outer diameter of the convex portion 47 is slightly smaller than the normal dimension depending on the processing conditions of the convex portion 47 and the concave portion 49, the top portion 50 of the convex portion 47 of the liner rings 41a and 41b is the concave portion 49. However, since the pressure in the discharge side chamber 35 is higher than the pressure in the suction side chambers 36 a and 36 b, the portions on the suction side chambers 36 a and 36 b side than the top 50 of the convex portion 47 of the liner rings 41 a and 41 b are the recess 49. Line contact can be made and sealed.

  Further, since the anti-rotation screw 54 is fitted in the anti-rotation hole 55, the liner rings 41a and 41b can be prevented from turning with respect to the respective fitting holes 42. At this time, in the circumferential direction, the top portion 50 of the convex portion 47 is in line contact with the concave portion 49 as shown in FIG. 3 in the entire range except one place where the anti-rotation screw 54 is provided. .

  In the first embodiment, the cross-sectional shape of the convex portion 47 and the cross-sectional shape of the concave portion 49 are formed in an arc shape, but may be a parabolic curved surface. As shown in the embodiment, it is not limited to the arc shape.

A second embodiment of the present invention will be described with reference to FIGS.
The cross-sectional shape of the concave portion 49 is an arc shape, the cross-sectional shape of the convex portion 47 is formed in a triangular shape (an example of a polygonal shape), and the convex portion 47 is in line contact with the concave portion 49 in the circumferential direction (sealing portion). For example). In addition, you may process the front-end | tip of the top part 50 into curved surfaces, such as a minute circular arc shape (R shape).

According to this, the same operation and effect as the first embodiment described above can be obtained.
Further, as shown in FIG. 10, two mountain-shaped outer peripheral surfaces 47 a and 47 b are formed on the convex portions 47 of the liner rings 41 a and 41 b, and one arc-shaped inner peripheral surface is formed on the concave portion 49 of the fitting hole 42. Since the liner rings 41a and 41b can be positioned in the radial direction A and the direction B of the axial center 38a only by forming 49a, the processing effort can be further reduced.

A third embodiment of the present invention will be described with reference to FIG.
The cross-sectional shape of the concave portion 49 is an arc shape, and the cross-sectional shape of the convex portion 47 is formed in a quadrangular trapezoidal shape (an example of a polygonal shape), and the convex portion 47 is in line contact with the concave portion 49 in the circumferential direction. , 50b (an example of a seal portion).

  According to this, since the two top portions 50 a and 50 b of the convex portion 47 are in line contact with the concave portion 49 of the fitting hole 42, there is a gap between the outer peripheral surface of each liner ring 41 a and 41 b and the inner peripheral surface of each fitting hole 42. The seal performance is further improved.

  Further, each liner ring 41a, 41b is provided with three outer peripheral surfaces 47a to 47c on the convex portion 47, and only one arcuate inner peripheral surface 49a is formed on the concave portion 49 of the fitting hole 42. Since 41a and 41b can be positioned in the radial direction A and the direction B of the axial center 38a, the labor of processing can be further reduced.

A fourth embodiment of the present invention will be described with reference to FIG.
The cross-sectional shape of the concave portion 49 is an arc shape, and the cross-sectional shape of the convex portion 47 is formed in a U shape (or may be a V shape), and the convex portion 47 is in line contact with the concave portion 49 in the circumferential direction. , 50b (an example of a seal portion).

  According to this, since the two top portions 50 a and 50 b of the convex portion 47 are in line contact with the concave portion 49 of the fitting hole 42, there is a gap between the outer peripheral surface of each liner ring 41 a and 41 b and the inner peripheral surface of each fitting hole 42. The seal performance is further improved.

  Further, each liner ring 41a, 41b is provided with three outer peripheral surfaces 47a to 47c on the convex portion 47, and only one arcuate inner peripheral surface 49a is formed on the concave portion 49 of the fitting hole 42. Since 41a and 41b can be positioned in the radial direction A and the direction B of the axial center 38a, the labor of processing can be further reduced.

A fifth embodiment of the present invention will be described with reference to FIG.
The cross-sectional shape of the recess 49 is formed in a V shape that expands in the direction B of the axis 38a of the rotation shaft 38 toward the inner peripheral side. The convex portion 47 has an arc shape in cross section, and has two seal portions 60 a and 60 b that are in line contact with the concave portion 49 in the circumferential direction.

  According to this, since the two seal portions 60a, 60b of the convex portion 47 are in line contact with the concave portion 49 of the fitting hole 42, the outer peripheral surface of each liner ring 41a, 41b and the inner peripheral surface of each fitting hole 42 are The sealing performance in between is further improved.

  Further, only one arc-shaped outer peripheral surface 47a is formed on the convex portion 47 of each liner ring 41a, 41b, and two V-shaped inner peripheral surfaces 49a, 49b are formed on the concave portion 49 of the fitting hole 42. Since each of the liner rings 41a and 41b can be positioned in the radial direction A and the direction B of the shaft center 38a, the labor of processing can be further reduced.

A sixth embodiment of the present invention will be described with reference to FIGS.
On the inner peripheral surface of the fitting hole 42, a protrusion 47 protruding inward in the radial direction is formed over the entire periphery. The cross-sectional shape of the convex portion 47 in the radial direction A around the axis 38a of the rotation shaft 38 is formed in an arc shape.

  Each liner ring 41a, 41b has a thin cylindrical ring main body portion 46 and a concave portion 49 formed on the outer peripheral surface of the ring main body portion 46 over the entire circumference and into which the convex portion 47 enters. The cross-sectional shape of the concave portion 49 in the radial direction A around the axis 38a of the rotation shaft 38 is formed in an arc shape.

  In addition, the radius r of the convex part 47 centering on the circumferential direction of the fitting hole 42 is smaller than the radius R of the recessed part 49 centering on the circumferential direction of the liner rings 41a and 41b. Moreover, the convex part 47 has the top part 50 (an example of a seal | sticker part) which carries out a line contact with the recessed part 49 in the circumferential direction.

Hereinafter, the operation of the above configuration will be described.
The top portion 50 of the convex portion 47 of the fitting hole 42 is in line contact with the concave portion 49 of each liner ring 41a, 41b, so that water is formed on the outer circumferential surface of each liner ring 41a, 41b and the inner circumferential surface of each fitting hole 42. Between the outer peripheral surface of each liner ring 41a, 41b and the inner peripheral surface of each fitting hole 42 can be sufficiently ensured. Further, instead of sealing by contact between surfaces (surface contact) as in the prior art, the surface between the outer peripheral surface of the liner rings 41a and 41b and the inner peripheral surface of the fitting hole 42 is sealed by line contact. Processing accuracy as high as contact is not required, and processing of the liner rings 41a and 41b and the fitting holes 42 can be easily performed.

  Further, each liner ring 41a, 41b has only one arcuate outer peripheral surface 49a formed in the concave portion 49, and only one arcuate inner peripheral surface 47a formed in the convex portion 47 of the fitting hole 42. Since the rings 41a and 41b can be positioned in the radial direction A and the direction B of the axial center 38a, the processing effort can be further reduced.

  If the outer diameter of the concave portion 49 is slightly smaller than the normal dimension depending on the processing conditions of the convex portion 47 and the concave portion 49, the top portion 50 of the convex portion 47 of the fitting hole 42 is lined with the concave portion 49. Although there is no contact, since the pressure in the discharge side chamber 35 is higher than the pressure in the suction side chambers 36a and 36b, the portion closer to the discharge side chamber 35 than the top 50 of the convex portion 47 of the fitting hole 42 is in line contact with the concave portion 49. can do.

  In each of the above embodiments, both suction centrifugal pumps 31 are given as an example of a pump, but pumps other than this type may be used.

It is the top view which removed the upper casing body of the pump in the 1st Embodiment of this invention. It is a side view of a pump same as the above. It is an expanded sectional view of the fitting part of the liner ring and fitting hole of a pump. It is sectional drawing of the recessed part of the fitting hole of a pump same as the above. It is a figure of a liner ring of a pump same as the above, (a) is a partially cutaway side view of a liner ring, and (b) is a XX arrow view of (a). It is a partial expanded sectional view of the liner ring of a pump same as the above. FIG. 6 is a view in which a pump casing is separated into a lower casing body and an upper casing body, and a liner ring is fitted into a lower fitting hole of the lower casing body. It is an expanded sectional view of the fitting part of the liner ring and fitting hole of the pump in the 2nd Embodiment of this invention. It is a figure of a liner ring of a pump same as the above, (a) is a partially cutaway side view of a liner ring, and (b) is a XX arrow view of (a). It is a partial expanded sectional view of the liner ring of a pump same as the above. It is an expanded sectional view of the fitting part of the liner ring and fitting hole of the pump in the 3rd Embodiment of this invention. It is an expanded sectional view of the fitting part of the liner ring and fitting hole of the pump in the 4th Embodiment of this invention. It is an expanded sectional view of the fitting part of the liner ring and fitting hole of the pump in the 5th Embodiment of this invention. It is an expanded sectional view of the fitting part of the liner ring and fitting hole of the pump in the 6th Embodiment of this invention. It is sectional drawing of the convex part of the insertion hole of a pump same as the above. It is a partially cutaway side view of the liner ring of the pump. It is the top view which removed the upper casing body of the conventional pump. It is sectional drawing of the fitting part of the liner ring and fitting hole of a pump same as the above. It is an expanded sectional view of the fitting part of the liner ring and fitting hole of a pump. It is the figure which removed the liner ring of the pump from the fitting hole similarly, (a) is a partially expanded sectional view of a liner ring, (b) is a partially expanded sectional view of a fitting hole.

Explanation of symbols

31 Pump 32 Casing 32a Lower casing body (first casing body)
32b Upper casing body (second casing body)
38 Rotating shafts 40a and 40b Impellers 41a and 41b Liner ring 42 Insertion hole 43 Predetermined gap 47 Convex part 49 Concave part 50, 50a and 50b Top part (seal part)
56 Anti-rotation means 60a, 60b Seal part r Radius of convex part R Radius of concave part

Claims (6)

In the casing, an impeller attached to the rotary shaft and a liner ring are provided,
The casing is divided into a first casing body and a second casing body in a plane parallel to the rotation axis,
A pump in which a predetermined gap is formed between the impeller and the liner ring,
The liner ring is fitted into a fitting hole formed in the casing,
A convex part is formed on one of the outer peripheral surface of the liner ring and the inner peripheral surface of the fitting hole facing the outer peripheral surface, and on the other side, a concave part into which the convex part enters is formed.
A pump characterized in that the convex part has a seal part in line contact with the concave part. The convex part is formed on the outer peripheral surface of the liner ring,
The pump according to claim 1, wherein the recess is formed on an inner peripheral surface of the fitting hole. The pump according to claim 2, wherein the recess of the fitting hole is formed in an arc shape. The convex part of the liner ring is formed in an arc shape,
4. The pump according to claim 3, wherein the radius of the convex portion centered in the circumferential direction of the liner ring is smaller than the radius of the concave portion centered in the circumferential direction of the fitting hole. The pump according to claim 2 or 3, wherein the convex portion is formed in a polygonal shape. The pump according to any one of claims 1 to 5, further comprising a detent means for preventing the liner ring from rotating with respect to the fitting hole.

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