JPH0633798B2 - Pump impeller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump impeller, and more particularly to a pump impeller that achieves a long service life, improved workability, and a compact mechanical seal.

(Prior Art) The impeller of a submersible pump is made of cast iron, high chromium steel, or the like. However, when these impellers are applied to a sludge liquid pump, etc., the wear caused by the slurry is severe,
Deformation occurs in a relatively short period of time and pump efficiency is reduced.

Therefore, the frequency of replacement of the impeller becomes high and the economy is reduced.

As an impeller that solves such a problem, for example, the sixth
As shown in FIG. 7 and FIG. 7, the metal core material 20 is made of urethane resin.
A structure covered with 21 is proposed.

In this type of impeller, the urethane resin 21 has excellent slurry resistance, so that wear deformation is significantly suppressed, the life is extended, and the frequency of replacement can be reduced.

(Problems to be Solved by the Invention) The urethane resin 21 has excellent slurry resistance, but has poor adhesiveness to the metal core material 20.
To this end, a large number of through holes 22 are formed in the metal core material 20, and the urethane resin 21 filled in the through holes 22 connects the urethane resin layers 21 on both front and back surfaces of the metal core material 20.

However, in the above-mentioned conventional impeller, the urethane resin layer 21 is formed around the opening of the shaft hole 24 into which the rotating shaft 23 is fitted and fixed.
The end of is exposed. Therefore, peeling occurs from the boundary portion B between the end portion and the metal core material 20, and this largely spreads over time, causing most of the urethane resin layer 21 to float up from the metal core material 20 and deform the impeller. Therefore, there is a drawback that the pump efficiency is lowered.

Further, since the metal core material 20 of the impeller is formed by casting, mechanical cutting, etc., the number of processing steps is large, the workability is poor, and more materials are used, which leads to an increase in cost.

Further, it does not include a member that constitutes a mechanical seal that seals the rotary shaft 23. That is, it is necessary to provide the mechanical seal at a position away from the impeller, so that the mechanical seal cannot be made compact. Therefore, there are problems that the number of parts is increased, the mounting dimension in the axial direction is lengthened, and the size of the pump is increased.

The present invention has been made in view of the above circumstances, and can improve the workability, reduce the weight and reduce the cost, and increase the peel strength of the synthetic resin layer to prolong the life, and The purpose of the present invention is to provide a pump impeller that can achieve reduction in power loss of the pump and can be effectively applied to a large-sized pump.

(Means for Solving the Problems) In order to achieve the above object, the impeller of the pump according to the first aspect of the present invention is provided with a back plate portion having a large number of small holes formed therethrough and a front surface of the back plate portion. A sheet metal core member having a plurality of protruding pieces formed by cutting and raising in a plurality of regions and penetrating a small hole, and comprising a sheet metal core member having an axial hole formed at the center of the back plate portion, A portion excluding the shaft hole is molded with a synthetic resin to form a synthetic resin blade that covers each projecting piece in the plurality of regions, and a synthetic resin layer that covers the peripheral portions of both ends of the shaft hole has a large rotating shaft diameter. It is sandwiched between the end face of the part and the tightening surface of the screw tightening member that is connected to the large diameter part and is screwed into the small diameter part that penetrates the shaft hole.

Further, an impeller for a pump according to a second aspect of the present invention has a back plate portion having a large number of small holes formed therethrough, and a plurality of blades protruding at the front surface of the back plate portion and having small holes formed therethrough. And,
A metal core material is provided, which has a shaft hole formed at the center of the back plate portion and a recess formed by fitting a rotary seal ring of a mechanical seal to the outer periphery of the shaft hole on the rear surface of the back plate portion. A portion excluding the shaft hole is covered with a synthetic resin layer, and a synthetic resin layer covering the peripheral portions of both ends of the shaft hole is continuously provided on the large diameter end surface of the rotary shaft and the large diameter portion. It is sandwiched by the tightening surface of the screw tightening member screwed into the small diameter portion that penetrates the shaft hole.

(Operation) According to the first and second aspects of the present invention, since the so-called punching metal having a large number of small holes formed therethrough is used as the metal core material, the impeller itself can be lightened. Therefore, the power loss of the pump is reduced. Further, the synthetic resin layer covering the peripheral portions of both ends of the shaft hole is sandwiched between the large-diameter end surface of the rotating shaft and the tightening surface of the screw fastening member so that the end portion of the synthetic resin layer is not exposed and the core is not exposed. Since the synthetic resin layers on the front and back are connected through the small holes formed in the material, the core material and the synthetic resin layer are securely bonded to each other, and the peel strength of the resin layer increases. As a result, the deformation of the impeller and the reduction of pump efficiency due to the floating of the synthetic resin layer are eliminated, the life of the impeller is extended, and the stability of pump operation can be maintained for a long period of time.

In addition, according to the first aspect of the present invention, in order to form the skeleton of the blade, it is not a single plate-shaped skeleton but is cut and raised from the sheet metal core material corresponding to the region of the blade portion. Since the skeleton is formed of a plurality of protrusions, the impeller applicable to a large-sized pump can be configured without being restricted by the curvature of the blade portion.

Further, according to the second aspect of the present invention, the rotary seal ring of the mechanical seal is fitted in the recess formed on the rear surface of the back plate portion of the metal core material, and between the rotary seal ring of the mechanical seal and the fixed seal ring on the pump casing side. Since the seals are used, the number of parts for the shaft sealing structure can be reduced, the mounting dimension in the axial direction can be shortened, and the mechanical seal can be made compact, which in turn contributes to downsizing of the entire pump.

(Embodiment) FIG. 1 is a front view showing a first embodiment of the present invention with a part of a synthetic resin layer removed, and FIG. 2 is a side view showing a cross section of the same portion. In these drawings, an impeller of a pump is shown. 1 is a metal core material 2 and a synthetic resin layer lined with the metal core material 2.
It is composed of three.

The metal core material 2 is a sheet metal core material formed by pressing a sheet metal, and has a circular back plate portion 2A and a plurality of regions on the front surface of the back plate portion 2A, that is, a synthetic resin described later in this embodiment. It has a plurality of protruding pieces 8 formed by cutting and raising in each of three regions where the blades are formed, and a shaft hole 4 is formed through the center of the back plate portion 2A.

The synthetic resin layer 3 is made of a urethane resin having excellent slurry resistance, and the back plate portion 2A is covered by resin-molding a portion of the metal core material 2 excluding the shaft hole 4, and the plurality of Synthetic resin blade covering the protruding piece 8 of
Forming a nine. In this way, by covering the metal core material 2 with the synthetic resin layer 3, the plurality of small holes 5 and 8a penetratingly formed in the back plate portion 2A and the projecting piece 8 are filled with the synthetic resin, and this filling is performed. The synthetic resin layer 3 that covers both the front and back surfaces of the back plate 2A and the synthetic resin layer 3 that covers both sides of the protruding piece 8 are linked together by the resin, and peeling of the synthetic resin layer 3 is strongly prevented. It is designed to be done.

In FIG. 3, reference numeral 6 denotes a rotary shaft, which has a large diameter portion 6A and a small diameter portion 6B concentrically and continuously connected to the large diameter portion 6A. The small diameter portion 6B is connected to the shaft of the impeller 1. By inserting a screw tightening member 7 consisting of, for example, a nut 7A and a washer 7B into a portion which penetrates the hole 4 and projects forward, the impeller 1
To the rotary shaft 6.

That is, the synthetic resin layer 3 that covers the periphery of both ends of the shaft hole 4 is
It is sandwiched between the end surface 6a of the large diameter portion 6A of the rotating shaft 6 and the tightening surface 7b of the screw tightening member 7, that is, the tightening surface 7b of the washer 7B.

According to the impeller 1 configured as described above, the end portion of the synthetic resin layer 3 that covers the peripheral portions of both ends of the shaft hole 4 is prevented from being separated from the boundary portion A with the metal core material 2, and the impeller 1 The life of can be extended. Moreover, the screw tightening member 7 is attached to the center of the impeller 1 where slurry such as sludge flows at the highest speed.
Exists and hides the synthetic resin layer 3, the impeller
The influence of the slurry on the center of 1 can be avoided.

In addition, since the metal core material 2 is made of sheet metal that can be formed by simple press working, the number of working steps is reduced and the impeller
The workability of 1 can be improved, and the cost can be reduced by reducing the materials used. In particular, since the blade with the highest degree of interference with the slurry is the synthetic resin blade 9 made of urethane resin, wear deformation of the blade is suppressed and impeller 1
It is possible to further extend the life of the.

Moreover, since the so-called punching metal with a large number of small holes formed through it is used as the metal core material 2,
The impeller 1 itself will be lightened, and the power loss of the pump will be small.

4 and 5 show an embodiment according to the third invention of the present invention. FIG. 4 shows an impeller 1 to which a metal core material 2 made of sheet metal is applied, and FIG. 5 shows a metal made of cast iron, for example. Impeller 1 with core 2 applied is shown. In these figures,
On the outer periphery of the shaft hole 4 on the rear surface of the back plate portion 2A of the metal core material 2,
An annular recess 11 into which the rotary seal ring 10A of the mechanical seal 10 is fitted is formed, and this recess 11 is also coated with the synthetic resin layer 3 in advance and the rotary seal ring 10A is fitted therein.

With such a structure, the impeller 1 is fixed to the rotary shaft 6 as shown in FIG.
The mechanical seal 10 in which the end face of the rotary seal ring 10A is hermetically sealed can be configured on the end face of the fixed seal ring 10B of the mechanical seal 10 provided in 12. Therefore, the number of parts is reduced as compared with the conventional shaft sealing structure, and the mounting dimension in the axial direction can be shortened, so that the pump can be downsized.

(Effect of the invention) As described above, according to the first invention and the second invention of the present invention, a large number of small holes are formed through as a metal core material,
Since the so-called punching metal is used, the impeller itself is lightened, and the power loss of the pump can be reduced. In particular, it is effective for a large-sized pump in which power loss is so large that it cannot be ignored.
Further, a synthetic resin layer covering the peripheral portions of both ends of the shaft hole is sandwiched between the large diameter end surface of the rotary shaft and the tightening surface of the screw tightening member,
The structure in which the ends of the synthetic resin layer are not exposed, and the synthetic resin layers on the front and back sides are connected through the small holes formed in the core material to ensure the coupling between the core material and the synthetic resin layer. , The peel strength of the resin layer can be made very large, and therefore, the deformation of the impeller and the reduction of pump efficiency due to the floating of the synthetic resin layer are eliminated, the life of the impeller is extended, and the operation of large submersible pumps in particular The effect of being able to secure stability of for a long period of time is exhibited.

In addition, according to the first aspect of the present invention, in order to form the skeleton of the blade, instead of forming a single plate-like skeleton, it is cut and raised from the sheet metal core material corresponding to the region of the blade portion. Since the skeleton is formed of a plurality of protrusions, the impeller applicable to a large-sized pump can be configured without being restricted by the curvature of the blade portion.

Further, according to the second aspect of the present invention, the rotary seal ring of the mechanical seal is fitted in the recess formed on the rear surface of the back plate portion of the metal core material, and between the rotary seal ring of the mechanical seal and the fixed seal ring on the pump casing side. Since the seals are used, the number of parts for the shaft sealing structure can be reduced, and the mechanical seal can be made compact by shortening the axial mounting dimension, which contributes to downsizing of the entire pump. be able to.

[Brief description of drawings]

FIG. 1 is a front view showing a first embodiment of the present invention with a part of a synthetic resin layer removed, FIG. 2 is a side view showing a section of the same portion, and FIG. 3 is a state in which an impeller is fixed to the rotary shaft. FIG. 4 is a side view showing a partial cross section, FIG. 4 is a front view showing a part of a synthetic resin layer showing another embodiment, FIG. 5 is a side view showing the same section, and FIG. An example front view and FIG. 7 are longitudinal side views. 1 …… Impeller 2 …… Metal core 2A …… Back plate 3 …… Synthetic resin layer 4 …… Shaft hole 6 …… Rotating shaft 6A …… Large diameter part 6B …… Small diameter part 6a …… End face 7…. … Screw tightening member 7b …… Clamping surface 8 …… Projecting piece 9 …… Synthetic resin blade 10 …… Mechanical seal 10A …… Rotating seal ring 11 …… Concave

Claims (2)

[Claims] 1. A back plate portion having a large number of small holes penetratingly formed therein, and a plurality of projections formed by cutting and raising in a plurality of regions on the front surface of the back plate portion, and penetratingly forming small holes, and The back plate portion is provided with a sheet metal core material having an axial hole formed therein, and a portion of the sheet metal core material excluding the axial hole is molded with a synthetic resin to form a synthetic resin blade covering each of the projecting pieces in the plurality of regions. Along with
A synthetic resin layer that covers the peripheral portions of both ends of the shaft hole is tightened with a large diameter end surface of the rotary shaft and a small diameter portion that is continuous with the large diameter portion and penetrates the shaft hole. An impeller for a pump, characterized in that it is sandwiched between the attached surface. 2. A back plate portion having a large number of small holes penetratingly formed therein, and a plurality of blades having a small hole penetratingly formed on the front surface of the back plate portion, and having a shaft hole at the center of the back plate portion. And a metal core member having a recess formed by fitting a rotary seal ring of a mechanical seal on the outer periphery of the shaft hole on the rear surface of the back plate portion,
A portion of the metal core material excluding the shaft hole is covered with a synthetic resin layer, and the synthetic resin layer covering the peripheral portions of both ends of the shaft hole includes a large-diameter end surface of the rotating shaft and the large-diameter portion. An impeller for a pump, wherein the impeller is sandwiched by a tightening surface of a screw tightening member that is screwed into a small-diameter portion that is connected to the shaft hole and penetrates the shaft hole.