JPS6410680B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a small pump, and more particularly to the structure of a water passage of a small pump such as a centrifugal pump.

[Conventional technology]

Conventionally, the volute chamber of a volute pump is
As disclosed in Publication No. 38-16179, etc., there are two types: one provided only on the casing (casing side wall) side of the pump, and the other, as shown in Fig. 10, where the swirl chamber 11a is divided between the casing 7a and the bracket 8a. There is something that has been formed. In addition, FIG. 10 is a partial sectional view showing a conventional example of a centrifugal pump, in which 1 is a motor shaft, 2 is an end bracket, 3 is a bearing, 4a is an impeller, 5 is a cooling fan, 6 is a fan boss, 9 10 is a pump chamber, 10 is a guide passage, 12 is a stuffing box, 13 is a gasket, 14 is a shaft sealing device, 15 is an inlet port, 20 is a mounting screw, 23
is the mounting hole.

[Problem to be solved by the invention] Among these centrifugal pumps, those in which the centrifugal chamber is formed only in the casing can be installed with the casing facing the bracket in a different direction, so the direction of the discharge port can also be changed. and has installation advantages in this respect. However, in this type of spiral, the cross section of the spiral is bag-like and the opening on the inlet side faces the outer circumference of the impeller, so the inner diameter (inlet) of the spiral chamber faces inward, so the spiral chamber cannot be enclosed in a casing. If it is only provided, this inward portion will inevitably have an undercut shape. Since such an undercut makes it difficult to remove the resin mold, conventionally the casing has been manufactured exclusively by casting using a core. If the pump casing is made of cast metal, it will be expensive.

On the other hand, in the case of the conventional example shown in FIG. 10, the spiral chamber 11a is also formed separately on the bracket 8a side, so although there is no undercut shape, there are the following problems.

That is, since the cross-sectional area of the passageway of the volute chamber 11a changes continuously, the size of each part of the volute chamber changes. Therefore, if the relative positional relationship of the casing 7a with respect to the bracket 8a is changed,
The spiral chamber element on the bracket side and the winding chamber element on the casing side do not match, making it impossible to form a spiral chamber together. Therefore, it is difficult to change the direction of the discharge port by changing the directionality of only the casing 7a.

As described above, it has been difficult for conventional centrifugal pumps to satisfy both the requirements of resin molding of the casing and the requirement to easily change the direction of the casing and discharge port. Moreover, the size of the pump head is determined by the external dimensions of the volute chamber,
There was a lack of ingenuity in reducing the external size of the volute chamber without impairing pump performance, and there was a limit to how compact this type of volute pump could be made.

The present invention has been made in view of the above points, and its purpose is to make the pump casing, bracket, etc. inexpensive resin molded products, and to improve the directionality of the pump casing and discharge port. It is an object of the present invention to provide a small pump that can be easily changed depending on the installation location of the pump and that can be made more compact without reducing the hydraulic efficiency of the pump.

[Means to solve the problem]

The present invention is configured as follows to achieve the above object.

Hereinafter, the present invention will be described with reference to the reference numerals of the embodiments shown in FIGS. 2 and 7 in order to facilitate understanding of the contents thereof. 2 is a vertical sectional view of a main part of the small pump of the embodiment, and FIG. 7 is a front view of the casing 7 used in the above embodiment, viewed from the direction of the impeller 4.

In the present invention, a pump chamber 9 is formed between a casing 7 and a bracket 8 on the front and rear surfaces of the pump. In the small pump, the bracket 8 has a curved surface 1 on the inner wall surface located outside the outer periphery of the impeller 4 to change the direction of the water flow from the radial direction to the front direction.
0-1 is provided, and a swirl chamber 11 without an undercut is formed on the inner wall surface of the casing 7 so as to face the surface of the guide channel 10, and the swirl chamber 11 and the guide channel are 10
The first half of the vortex chamber 11 (between E and E in FIG. 7) is made into a circular shape with the same outer diameter.
The inner wall surface of the casing at that position is tilted so that the depth gradually increases, and in the latter half (between the lower part and the lower part in Fig. 7), the width gradually increases in the inner diameter direction. , the cross section of the passageway of the swirl chamber 11 is gradually increased until it reaches the discharge port 16.

[Effect]

According to the present invention having such a configuration, water subjected to centrifugal force by the impeller 4 during pump operation is
After being ejected from the outer periphery of the impeller 4, the flow is smoothly converted from the radial direction to the front direction by the curved guide passage 10 provided on the inner wall surface of the bracket 8, and the flow is smoothly converted from the radial direction to the front direction. It flows into the swirl chamber 11. The water that has flowed into the swirl chamber 11 flows through the water passage inside the swirl chamber 11 like the water flow W shown in FIG. The second half of the low
Since the width of the gap changes in the inner diameter direction and the cross-sectional area of the passageway increases smoothly up to the discharge port 16, the flow rectification inside the swirl chamber 11 is sufficiently performed, reducing hydraulic efficiency. The water can be quickly guided to the discharge port 16 side without any problems.

In the present invention, since the swirl chamber 11 on the casing 7 side faces the front of the guide passage 10 on the bracket 8 side, the opening serving as the entrance of the swirl chamber 11 can be directed toward the inner wall of the bracket (the guide passage 10). In other words, the spiral chamber 11 opens laterally). Therefore, there is no need for the spiral chamber to face inward as in the conventional case, so the spiral chamber 11 without an undercut can be formed on the inner wall surface of the casing 7 so as to face the front of the guide passage 10. Undercuts can be eliminated. Further, since the guide passage 10 on the side of the bracket 8 also opens in the direction of the casing 7 (laterally), the opening does not face inward, and the bracket 8 can also be free from undercuts. Therefore, the casing 7 and the bracket 8 can be easily molded from resin.

Further, the present invention provides a spiral chamber 11 on the casing 7 side.
The structure is such that the guide passage 10 on the side of the bracket 8 faces each other, but the spiral chamber 11 and the guide passage 10 are
Since both have a circular outer diameter with the same outer diameter, even if the relative positional relationship of the casing 7 to the bracket 8 is changed in the circumferential direction, the spiral chamber 1 is always the same.
1 and the guide passage 10 match in a compatible state. Therefore, casing 7 with respect to bracket 8
The directionality of the discharge port 16 can be changed arbitrarily and the directionality of the discharge port 16 can be changed accordingly. Note that even if the outer shape of the swirl chamber 11 is circular as described above, the depth of the passageway of the swirl chamber 11 changes between E and R in the first half, and the width gradually gradually increases in the inner diameter direction between E and R in the rear half. Since the changes are made so that it spreads to
There is no problem in changing the cross-sectional area of the passageway of the swirl chamber 11. Furthermore, when changing the cross-sectional area of the passageway in the vortex chamber 11, it is done by changing the depth of the passageway and changing the width in the inner diameter direction, so there is no need to expand the outer diameter of the volute chamber 11 outward. Especially in the first half, the depth is not changed and the width is not widened.
Accordingly, the diameter of the entire swirl chamber can be reduced, and the casing can be made more compact. In addition, if the cross-sectional area of the passageway of the volute chamber is changed from the beginning only by the width in the inner diameter direction, the outer shape of the volute chamber becomes correspondingly larger in order to secure an involute inside the passageway.

〔Example〕

An embodiment of the present invention will be described based on the drawings.

First, FIG. 1 is an external perspective view of a small pump according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of the main part thereof, and FIGS. 3 to 6 are specific details of the discharge pipe. It is an explanatory diagram showing an example of a connection state.

In Figure 2, the parts are mainly explained: 1 is the motor shaft, 2 is the end bracket, 3 is the bearing, and 4 is the motor shaft.
is an impeller, 5 is a cooling fan, and 6 is a fan boss.

7 is a casing, 8 is a bracket, 9 is a pump chamber, 10 is a guide passage, 10-1 is a curved surface, 11 is a swirl chamber, 12 is a stuffing box, 13 is a gasket, 14 is a shaft sealing device, 15 is a suction port, 16 is a discharge port, and 17 is a plug.

Further, 18 in FIGS. 3 to 6 is a discharge pipe, 19 is a base, 20 is a mounting screw, 21 in FIG. 2 is a guide, and 22 is a discharge passage. Note that the base 19 is provided integrally with the end bracket 2.

Here, the detailed configuration will be described later, and the configuration will be briefly described. The motor shaft 1 is rotatably supported by an end bracket 2 via a bearing 3, and a pumping action is performed by rotating an impeller 4 screwed onto the tip.

The cooling fan 5 is press-fitted onto the outer periphery of a fan boss 6 fixed between the bearing 3 and the impeller 4 so as to be held on the outer periphery of the motor shaft 1 by the tightening force of the impeller 4. The impeller 4 is
Pump chamber 9 between casing 7 and bracket 8
Rotates and pumps water inside.

The pump chamber 9 includes a guide passage 10 provided on the inner wall surface of the bracket 8 so as to continue to the discharge outer peripheral opening of the impeller 4.
It consists of a swirl chamber 11 located in front of the impeller 4 and provided only on the casing 7 side to perform a rectifying action, and a stuffing box 12 provided behind the impeller 4 on the bracket 8 side.

The space between the casing 7 outside the spiral chamber 11 and the bracket 8 is sealed against the outside by a gasket 13, and the inside of the stuffing box 12 is connected to the shaft provided between the impeller 4 and the bracket 8. Water-sealed by a sealing device 14 .

Further, the suction side of the impeller 4 is open to the suction port 15 of the casing 7 , and the exit side of the swirl chamber 11 is connected to the discharge port 16 of the casing 7 .

The suction port 15 is provided coaxially with the impeller 4, and the discharge ports 16 are screwed so as to be located vertically and horizontally around the suction port 15, as shown in FIGS. 3 to 6, which will be described later. It is now possible to combine

Further, a plug 17 is attached to the upper part of the bracket 8, and is screwed in so as to be watertight.
By removing the plug 7, the air in the pump chamber 9 can be removed or water can be injected into the pump chamber 9. It is upward regardless of.

With the above configuration, when the impeller 4 rotates,
Water is pumped up in the following order: suction port 15 → impeller 4 → guide passage 10 → swirl chamber 11 → discharge port 16.

Here, the guide passage 10 and the swirl chamber 11, which are the main points of this embodiment, will be explained with reference to FIGS. 7 to 9 in addition to FIG. 2.

Figure 7 is a front view of the casing to explain the shape of the spiral chamber, Figure 8 is a developed view of the cross section taken along lines A to C in Figure 7, and Figure 9 is the location of its mounting screws. FIG.

As described earlier with reference to FIG. 2, in this embodiment, first, the pump chamber 9 is configured to perform pumping action using the centrifugal force generated by the rotation of the impeller 4, and perform a rectification action in the volute chamber 11. , is formed by a casing 7 on the front and a bracket 8 on the rear.

And in something thus formed,
As shown in FIG. 2, on the inner wall of the bracket 8, outside the outer periphery of the impeller 4 (upper and lower sides in FIG. 2),
Forming a curved surface 10-1 that deflects the water flow from the radial direction to the front direction (left side in FIG. 2), and providing a guide passage 10 by this curved surface 10-1,
A swirl chamber 11 is provided on the inner wall of the casing 7 so as to face the front of the guide passage 10. A bracket 8 is attached to the front surface of the outer periphery of the impeller 4 (left side in Fig. 2).
The guide 2 of the guide passage 10 extends along the side of the
1 will be provided.

Here, the water given centrifugal force by the impeller 4 is
The water is ejected from the outer circumference of the impeller 4 into the guide passage 10, and the wall of the guide passage 10 on the bracket 8 side has an arcuate curved surface 10-1 so as to smoothly guide the water to the swirl chamber 11 in front. Further, the guide 21 provided on the outer periphery of the impeller 4 protrudes outward, and works together with the wall of the bracket 8 to quickly guide water to the swirl chamber 11.

As a result, the water flowing into the swirl chamber 11 is
Like the water flow W shown in FIGS. 7 and 8, it quickly flows into the discharge port 16 via the discharge passage 22, but the above-mentioned guide 21 allows the water in the guide passage 10 and the swirl chamber 11 to mutually The two are separated so that they do not interfere and disrupt water flow, reducing hydraulic efficiency.

As described above, in this embodiment, the guide passage 10 is provided on the bracket 8 side, and the spiral chamber 1 on the casing 7 side is provided.
1 is arranged so as to face the front of the guide passage 10, so that the entrance side opening of the swirl chamber 11 does not face inward but faces the guide passage 10 in a sideways state. Therefore, the swirl chamber 11 and, in turn, the casing 7 have a shape without undercuts. In addition, the spiral chamber 1
1 and the guide passage 10 are circular with the same outer diameter, and as shown in FIG. 2, when the casing 7 and the bracket 8 are combined, the outer diameters of both the swirl chamber 11 and the guide passage 10 match It has a shape that fits together.

Incidentally, the cross-sectional area of the passageway of the swirl chamber 11 needs to increase smoothly from the beginning of winding to the discharge port 16 in order to exhibit the function of rectification. In this embodiment, the spiral chamber 11 is constructed as follows under the constraint that the outer shape of the spiral chamber 11 is circular.
1. Change the cross-sectional area of the water passage.

7 and 8 both show the shape of the swirl chamber 11, FIG. 7 is a view of the casing 7 seen from the impeller 4 side, and FIG. 8 is a cross-sectional development view along lines A to C. . The first half of the swirl chamber 11 between A and B is formed by forming an inclination downward toward E at the inner wall surface position of the casing corresponding to the space between E and B, as shown in FIG. In other words, the width is gradually increased in the direction of the inner diameter as shown in Fig. 7, while the depth remains unchanged between the latter half of the loaf.In other words, the inner diameter is involute. In this way, the spiral chamber 11 smoothly increases its passageway cross section in the direction of A → B → C. As a result, the intended function of the rectifying action of the volute chamber 11 is achieved.

The configuration of the pump chamber 9 with the above-mentioned shape improvements allows the guide passage 10 and the volute chamber 11 to have a structure without undercuts in the bracket 8 and casing 7, without reducing hydraulic efficiency. This makes it possible to make the bracket 8 and the casing 7 into resin molded products or die-cast products instead of casting products using a core.

Further, the spiral chamber 11 whose area and shape are changed in the circumferential direction is provided only inside the casing 7, and the spiral chamber 11 and the guide passage 1 face each other.
0 have a circular outer shape with the same outer diameter, so even if the relative positional relationship of the casing 7 in the circumferential direction with respect to the bracket 8 is changed, the outer shapes of the swirl chamber 11 and the guide passage 10 are always the same. matches in conformance state. Therefore, the casing 7 can be attached to the bracket 8 while changing its direction in the circumferential direction arbitrarily, and accordingly, the direction of the discharge port 16 can be changed. In other words, the discharge port 16 is connected to the suction port 1 regardless of the positional relationship with the bracket 8.
5, the pump action can be performed without affecting its function at all, regardless of whether it is placed in the upper, lower, left, or right position of the pump.

As described above, if the discharge port 16 is made to be able to change its position vertically and horizontally relative to the suction port 15, the piping when the pump is installed can be connected either vertically or horizontally depending on the surrounding situation. It has the advantage of being selective. Figures 3 to 6 show the connection state of each discharge pipe 18 in those cases, with the base 19 always facing down, the upper side in Figure 3, the right side in Figure 4, and the connection state of each discharge pipe 18 in Figure 5. The discharge pipe 18 can be connected downward and to the left in FIG.

The movement of the discharge port 16 is made possible by rotating the casing 7 and tightening the mounting screw 20 again. By improving the shape of the water passage portion of the pump chamber 9, the mounting pitch P of the mounting screw 20 shown in FIG. 3 can be reduced, and as a result, at least: To make it possible to reduce the size of the entire pump and make it compact.

In other words, when changing the cross-sectional area of the passageway in the volute chamber 11, the depth and width of the passageway are widened in the inner diameter direction, so there is no need to increase the outer diameter of the volute chamber 11, especially in the first half. Since the depth is changed and the width is not increased, the diameter of the spiral chamber can be reduced accordingly. Then, the casing 7 is attached through the attachment hole 23 as shown in FIG.
This is done by tightening the mounting screw 20,
As a result of making the shape of the spiral chamber 11 more compact, the ninth
As shown in the figure, the outer diameter of the casing 7 can be made smaller, and the distance between the motor shaft 1 and the center of the mounting screw 20 can also be made smaller as indicated by l in the figure. On the other hand, the spiral chamber 11a shown in FIG. 10 according to the conventional example
changes so that the area and shape gradually increase in the outer circumferential direction, and accordingly, the center distance l1 between the motor shaft 1 and the mounting screw 20 increases such that l1>l, and the above-mentioned It is not possible to comply with such requests.

Due to the above, in this example,
Since the above l is smaller, as a result, the mounting pitch P shown in Figure 3 can be made smaller, resulting in more compact products, lower material costs due to material savings, and lower molding costs. enable.

Furthermore, another effect of the above embodiment is that, as seen in the enlarged outline of FIG. 2, for example, its lower part, the outer surface of the casing 7 is different from the uneven lower part in the outline of the conventional example shown in FIG. As shown in FIG. 1, the outer surface of the pump as a whole can have an external shape with extremely few irregularities. This can significantly reduce the amount of fillet and save material, compared to the conventional example shown in FIG. 10, which is built up to make its appearance smooth.

As described above, according to the above-mentioned embodiment, the discharge port 16 can be arranged in either the upper, lower, left or right directions without reducing the hydraulic efficiency of the pump, is compact, has no undercuts in the casing 7 or the bracket 8, and is inexpensive in terms of materials and molding costs. It is possible to obtain a small pump that can also be installed in the direction of .

Note that although the guide 21 is provided in the above embodiment, it is not necessary to provide it, and if it is not provided, the turbulence prevention feature will not be effective and the effect will be slightly reduced. However, it is sufficient for practical use.

〔Effect of the invention〕

As described above, according to the present invention, the casing and bracket can be formed without an undercut, so the pump casing, bracket, etc. can be manufactured by resin molding at low cost and with excellent productivity.Moreover, the volute chamber can be provided only on the casing side. In addition, since the spiral chamber on the casing side and the guide passage on the bracket side have a circular outer shape with the same outer diameter, it is possible to change the positional relationship of the casing and its discharge port relative to the bracket. As a result,
The direction of the pump's discharge port can be easily changed depending on the location where the pump is installed, and the vortex chamber is formed in a shape that does not expand outward without impairing its function, so hydraulic efficiency is not reduced. The entire pump can be made more compact.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of a small pump according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of the main part thereof,
3 to 6 are explanatory views of the discharge pipe connection state, FIG. 7 is a front view of the casing to explain the shape of the swirl chamber, and FIG. 8 is a FIG. 9 is a developed view of the cross section along , and FIG.
FIG. 0 is a cross-sectional view of main parts for explaining the positions of mounting screws in a conventional example. 1... Motor shaft, 4... Impeller, 7... Casing, 8... Bracket, 9... Pump chamber, 10
...Guidance passage, 10-1...Curved surface, 11...Vortex chamber, 16...Discharge port, 18...Discharge pipe, 20...
Mounting screw, 21...Guide, 22...Discharge passage.

Claims (1)

[Claims] 1. Pumping water by centrifugal force caused by the rotation of an impeller,
A pump chamber with a vortex chamber for rectification,
In a small pump formed between a front and rear casing and a bracket, a curved surface located on the inner wall surface of the bracket outside the outer periphery of the impeller and changes the direction of water flow from the radial direction to the front direction. A shaped guide passage is provided, and a spiral chamber without an undercut is formed on the inner wall surface of the casing so as to face the front surface of the guide passage, and the spiral chamber and the guide passage are connected so that the outer diameters of both are While keeping the same circular outer shape, the first half of the volute chamber changes so that the depth gradually deepens by inclining the inner wall surface of the casing at that position, and the second half changes so that the width gradually increases in the inner diameter direction. A small pump characterized in that the passageway structure includes a passageway cross-sectional area of the swirl chamber that gradually increases up to the discharge port. 2. In what is stated in claim 1,
A small impeller is provided with a guide for the guide passage extending facing the curved surface of the bracket on the front surface of the outer periphery of the impeller, and the guide is set so that the water flow in the guide passage and the water flow in the swirl chamber do not interfere with each other. pump.