JP2016186296A - Pump and assembly method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump which prevents back flow of water to improve the pump efficiency while facilitating assembly and designing.SOLUTION: A pump includes an impeller (10) and a casing (20) for storing the impeller (10). In the pump, an annular gap (G) is formed between an outer peripheral surface (11a) of a suction port (11) and the casing (20) in the impeller (10). The outer peripheral surface (11a), which is located at the inner side of the annular gap (G) with respect to the casing (20), includes a seal member (30). The seal member (30) is stored so as to move in an axial direction on the outer peripheral surface (11a) between an open state, in which the seal member (30) is separated from the annular gap (G), and a closed state, in which the seal member (30) is moved from the open state to the annular gap (G) side to close the annular gap (G).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pump including an impeller and a casing that accommodates the impeller, and an assembling method thereof.

  Conventionally, in this type of pump, the outer peripheral surface of the suction port of the impeller and the casing are normally in non-contact with each other so that the operation is not hindered by the contact between the impeller and the casing that is rotationally driven. Is in a state of being formed. And in this case, the seal member is sandwiched in the annular gap so that the water does not flow backward from the high pressure side to the low pressure side of the impeller that is rotationally driven through the annular gap. Backflow is prevented and pump efficiency is improved (see, for example, the Chinese Utility Model Publication No. 200095545 (Patent Document 1)).

  However, in this case, it is necessary to assemble the casing and the impeller so that the seal member is sandwiched in the annular gap, and the dimensional accuracy of the impeller is required so that the seal member is appropriately sandwiched in the annular gap. There was complexity in processing, assembly, and design. In addition, the seal member is attached to the gap between the outer peripheral surface of the suction port of the impeller and the casing, and strong friction acts on the seal member, and the wear due to the rotational drive of the impeller is severe and there is a problem in durability. .

China Utility Model Notification No. 200949545 Specification

  It is to improve the pump efficiency by preventing back flow of water while facilitating assembly and design.

The pump according to the present invention is
Impeller,
A casing for housing the impeller,
An annular gap is formed between the outer peripheral surface of the suction port in the impeller and the casing,
In the outer peripheral surface inside the casing from the annular gap, a seal member is provided,
In the outer peripheral surface, the seal member is in an open state in which the seal member is separated from the annular gap, and in a closed state in which the seal member moves from the open state to the annular gap to close the annular gap. It is accommodated so as to be movable in the axial direction.

  Hereinafter, preferred embodiments of the pump according to the present invention will be described. However, the scope of the present invention is not limited by the preferred embodiments described below.

  As one aspect, it is preferable that a length in the axial direction in which the seal member can move on the outer peripheral surface is larger than a width in the axial direction of the seal member.

  As one aspect, it is preferable that a movement restricting portion for restricting the movement of the seal member in the axial direction is provided on the outer peripheral surface inside the casing with respect to the casing.

  As one aspect, it is preferable that the seal member is an elastic body.

  As one aspect, it is preferable that the seal member is an O-ring.

  According to the above configuration, the seal member accommodated in the outer peripheral surface of the suction port so as to be movable in the axial direction moves from the open state separated from the annular gap to the annular gap side, and enters a closed state that closes the annular gap. As a result, the annular gap can be closed to prevent the reverse flow of water from the high pressure side to the low pressure side of the impeller, and the pump efficiency can be improved. In addition, since the seal member takes a form of closing the annular gap from the outside, it is not necessary to design the width of the annular gap or the width of the seal member strictly as compared with the case where the seal member is sandwiched in the annular gap, and the design is also possible. Easy to do. Thus, it is possible to prevent the back flow of water while facilitating assembly and design, and to improve the pump efficiency.

The assembly method of the pump according to the present invention is as follows:
An assembly method of a pump comprising an impeller and a casing for housing the impeller, wherein an annular gap is formed between an outer peripheral surface of a suction port in the impeller and the casing,
A seal member is attached to the outer peripheral surface,
The impeller is accommodated in the casing in a state where the seal member is separated from a position where the annular gap is formed.

  According to this configuration, the pump can be assembled while the seal member is disposed at a position separated from the position where the annular gap is formed, and the casing and the impeller are compared with the case where the seal member is sandwiched in the annular gap. Therefore, it is easy to assemble the seal member without paying attention to the positional relationship between the seal member and the seal member.

Explanatory drawing of impeller and casing part in pump Enlarged view of the seal structure in the open state Enlarged view of the seal structure in the closed state Pump assembly drawing

  DESCRIPTION OF EMBODIMENTS Embodiments of a pump and a pump assembly method according to the present invention will be described with reference to the drawings. The pump 1 according to this embodiment includes an impeller 10 and a pump casing 20 that houses the impeller 10. In the pump 1, an annular gap G is formed between the outer peripheral surface 11 a of the suction port 11 in the impeller 10 and the casing 20. A seal member 30 is provided on the outer peripheral surface 11 a of the suction port 11 on the inner side of the casing 20 from the annular gap G. The seal member 30 is separated from the annular gap G on the outer peripheral surface 11 a of the suction port 11. The seal member 30 is accommodated so as to be movable in the axial direction between an open state and a closed state in which the seal member 30 moves from the open state toward the annular gap G to close the annular gap G. Thereby, it is possible to prevent back flow of water while facilitating assembly and design, and to improve pump efficiency. In addition, when the pump 1 according to the present embodiment is applied to sewage, it also has an effect of preventing fine dust and the like from entering the pump 1 through the annular gap G and contributes to stable operation of the pump 1. . Hereinafter, the pump 1 according to the present embodiment will be described in detail.

  The pump 1 according to this embodiment includes an impeller 10 and a casing 20 that houses the impeller 10, and has a feature in a seal structure S between the impeller 10 and the casing 20. As shown in FIG. 1, a main shaft 2 is attached to the impeller 10, and the main shaft 2 is supported by a bearing (not shown) provided in the bearing box 3. A mechanical seal 4 is provided in the bearing box 3. The casing 20 is connected to the bottom surface of the bearing box 3. The main shaft 2 is connected to a motor (not shown) and is rotated by driving the motor. It should be noted that configurations other than the seal structure S, such as a bearing that receives the main shaft 2 attached to the impeller 10, a bearing box connected to the upper portion of the casing 20, a motor that is a driving source of the main shaft 2, and a motor casing that houses this motor, etc. A specific configuration may be a known configuration, which is not described here, and the seal structure S between the impeller 10 and the casing 20 will be described below.

  The impeller 10 includes a suction port 11 that is formed so as to protrude in the axial direction at the center of the lower end. Moreover, the suction inlet 11 is formed so that the outer peripheral surface 11a may become a surface parallel to an axial direction. As a result, the suction port 11 has the same outer peripheral diameter regardless of the position in the axial direction, and the seal member 30 can move smoothly on the outer peripheral surface 11a.

  The casing 20 includes a suction port 21 that is formed so as to protrude in the axial direction at the center of the lower end, and a discharge port 22 that opens in the horizontal direction. A receiving portion 23 that receives the suction port 11 of the impeller 10 is provided inside the suction port 21 of the casing 20. The opening diameter of the receiving portion 23 is slightly larger than the outer peripheral diameter of the suction port 11 of the impeller 10, whereby the space between the outer peripheral surface 11 a of the suction port 11 in the impeller 10 and the receiving portion 23 of the casing 20 is set. Is formed with an annular gap G so that the suction port 11 of the impeller 10 and the receiving portion 23 are not in contact with each other (see FIGS. 2 and 3). Further, the opening diameter of the receiving portion 23 may be made larger than the outer peripheral diameter of the suction port 11, and the gap between the opening diameter and the outer peripheral diameter (annular gap G) may be made small by an exchange member such as a ring.

  As shown in FIG. 2, in the outer peripheral surface 11a of the suction port 11 on the inner side of the suction port 11 on the inner side with respect to the casing 20 from the annular gap G in the outer peripheral surface 11a of the suction port 11, in the present embodiment, an elastic member is used as an example of the seal member. An O-ring 30 is accommodated. The wire diameter (thickness) d1 of the O-ring 30 is larger than the width d2 of the annular gap G so that the seal member (O-ring) does not fall out of the annular gap G. The inner diameter of the O-ring 30 is substantially the same as the outer diameter of the suction port 11, and the O-ring 30 is in close contact with the outer peripheral surface 11 a of the suction port 11.

  The O-ring 30 that is in close contact with the outer peripheral surface 11 a of the suction port 11 rolls on the outer peripheral surface 11 a of the suction port 11, so that the shaft between the upper end 12 of the outer peripheral surface 11 a of the suction port 11 and the annular gap G It can move in the direction. That is, the O-ring 30 has an open state in which the O-ring 30 is separated from the annular gap G (see FIG. 2) on the outer peripheral surface 11a of the suction port 11, and the O-ring 30 moves from the open state to the annular gap G side. In the closed state (see FIG. 3) that closes the annular gap G, it is accommodated so as to be movable in the axial direction. Since the O-ring 30 has a circular cross section, the O-ring 30 can smoothly roll on the outer peripheral surface 11a of the suction port 11, and the movement from the open state to the closed state is smoothly performed. Further, if the outer peripheral surface 11a on which the O-ring 30 moves is subjected to machining such as polishing, it is preferable that the O-ring moves more smoothly.

  The length in the axial direction in which the O-ring 30 can move on the outer peripheral surface 11 a of the suction port 11, that is, the length between the upper end 12 of the outer peripheral surface 11 a of the suction port 11 and the annular gap G is the line of the O-ring 30. It is larger than the diameter (corresponding to the width in the axial direction). As a result, a space in which the O-ring 30 can move between an open state and a closed state is secured.

  Further, since the outer peripheral surface 11a is formed to be a surface parallel to the axial direction, the O-ring 30 can move in the axial direction along the outer peripheral surface 11a. Further, the upper end 12 restricts the movement of the O-ring 30 upward in the axial direction from the upper end 12. That is, the surface parallel to the axial direction on the outer peripheral surface 11 a and the upper end 12 constitute a movement restricting portion that restricts the movement of the O-ring 30 in the axial direction. In other words, on the outer peripheral surface 11a of the suction port 11 on the inner side of the casing 20 from the annular gap G, a movement restricting portion that restricts the movement of the O-ring 30 in the axial direction is provided.

  Next, a method for assembling the pump 1 according to this embodiment will be described. In order to form the seal structure S, the pump 1 can be assembled as follows. First, as shown in FIG. 4, an O-ring 30 is attached to the outer peripheral surface 11 a of the suction port 11 in the impeller 10. Thereafter, the impeller 10 is accommodated in the casing 20 while the suction port 11 of the impeller 10 is received by the receiving portion 23 of the casing 20 in a state where the O-ring 30 is separated from the position where the annular gap G is formed. Finally, the casing 20 is connected to the bottom surface 3 a of the bearing box 3.

  Thus, the pump 1 can be assembled while the O-ring 30 is disposed at a position separated from the position where the annular gap G is formed. Compared to the case where the O-ring 30 is sandwiched between the annular gap G, the pump 1 can be assembled. Easy assembly. Compared to the case where the O-ring 30 is sandwiched between the annular gap G, strict dimensional accuracy such as the width of the annular gap G, the inner diameter and the wire diameter of the O-ring is not required, and the design can be facilitated. Further, in the assembly, the receiving portion 23 serves as a guide portion for the casing 20 with respect to the impeller 10, and the assembly can be performed more easily.

  Next, the function of the seal structure S will be described. First, as shown in FIG. 2, in the seal structure S, the O-ring 30 is in an open state separated from the annular gap G immediately after the pump is assembled. When the impeller 10 is rotated by operating the pump 1, water is sucked from the suction ports 11 and 21 and discharged from the discharge port 22. At this time, the radially outer side of the impeller 10 becomes high pressure due to centrifugal force, and the suction ports 11 and 21 side become low pressure due to water being sucked in, so the annular gap G is formed from the high pressure side toward the low pressure side. As a result, reverse flow of water occurs. On the other hand, in the seal structure S, since the O-ring 30 is movable in the axial direction, the O-ring 30 is moved from the open state to the annular gap G side by being pushed by the reverse flow of water, Eventually it moves to a closed state that closes the annular gap G. Even after reaching the closed state, the O-ring 30 is pushed (sucked) toward the annular gap G due to the pressure difference between the high-pressure side and the low-pressure side, and the O-ring 30 that is an elastic body is in close contact with the annular gap G while being elastically deformed. As a result, the annular gap G is closed more firmly (see FIG. 3). In this way, the annular gap G is closed by the O-ring 30 to prevent the back flow of water, and the pump efficiency is improved.

  When the O-ring 30 is sandwiched between the annular gaps G, the O-rings 30 are worn from both sides contacting the impeller 11 and the casing 20. The O-ring 30 is only worn on one side, and the durability is enhanced.

[Other Embodiments]
Finally, other embodiments of the pump 1 and the method for assembling the pump 1 according to the present invention will be described. Note that the configurations disclosed in the following embodiments can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction arises.

(1) In the above embodiment, the configuration using an elastic O-ring as the seal member has been described as an example. However, the embodiment of the present invention is not limited to this. For example, the member may not be an elastic body, and a member of another material / shape such as an X ring may be used instead of the O ring.

(2) In the above-described embodiment, the example in which the surface parallel to the axial direction on the outer peripheral surface 11a and the upper end 12 configure the movement restricting portion that restricts the movement of the O-ring 30 in the axial direction has been described. However, the embodiment of the present invention is not limited to this. For example, any one that restricts the movement of the O-ring 30 in the axial direction may be used. Further, if the O-ring 30 is accommodated so as to be movable in the axial direction between the open state and the closed state, the movement restricting portion may not be provided.

(3) In the above embodiment, the example in which the annular gap G is opened in the axial direction by being formed between the outer peripheral surface 11a of the suction port 11 and the receiving portion 23 of the casing 20 has been described. However, the embodiment of the present invention is not limited to this. For example, the annular gap G may be opened in the horizontal direction. In this case, for example, the annular gap G is not provided between the front end surface of the suction port 11 and the inner surface of the casing 20 of the outer peripheral surface 11a of the suction port 11 which is not provided with the receiving portion 23 and is parallel to the horizontal direction. May be formed.

(4) Regarding other configurations, it should be understood that the embodiments disclosed herein are illustrative in all respects and that the scope of the present invention is not limited thereby. Those skilled in the art will readily understand that modifications can be made as appropriate without departing from the spirit of the present invention. Accordingly, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention.

  The present invention can be used, for example, for various pumps and their assembly.

DESCRIPTION OF SYMBOLS 1 Pump 10 Impeller 11 Suction port 11a Outer peripheral surface 20 Casing 30 O-ring (seal member)
G annular gap

Claims (6)

Impeller,
A casing for housing the impeller,
An annular gap is formed between the outer peripheral surface of the suction port in the impeller and the casing,
In the outer peripheral surface inside the casing from the annular gap, a seal member is provided,
In the outer peripheral surface, the seal member is in an open state in which the seal member is separated from the annular gap, and in a closed state in which the seal member moves from the open state to the annular gap to close the annular gap. A pump housed in an axially movable manner.   The pump according to claim 1, wherein a length in the axial direction in which the seal member can move on the outer peripheral surface is larger than a width in the axial direction of the seal member.   The pump according to claim 1, wherein a movement restricting portion that restricts movement of the seal member in the axial direction is provided on the outer peripheral surface on the inner side of the casing with respect to the annular gap.   The pump according to any one of claims 1 to 3, wherein the seal member is an elastic body.   The pump according to any one of claims 1 to 4, wherein the seal member is an O-ring. An assembly method of a pump comprising an impeller and a casing for housing the impeller, wherein an annular gap is formed between an outer peripheral surface of a suction port in the impeller and the casing,
A seal member is attached to the outer peripheral surface,
An assembly method for accommodating the impeller in the casing in a state where the seal member is separated from a position where the annular gap is formed.

Images