JP2551567Y2 - Centrifugal pump - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal pump. 2. Description of the Related Art When it is desired to change the discharge rate as an intrinsic performance of a pump, it is usually necessary to design by increasing or decreasing the width of an impeller, and at the same time, to increase or decrease the axial dimension of the vortex chamber. . [0003] Further, depending on the use of the pump, in a centrifugal pump used in fresh water, an impeller is housed in a swirl chamber in a state where the lower edge of the impeller plate is brought close to the suction cover panel surface. When used in sewage, the swirl chamber has a drawback that solid matter is easily clogged. For this reason, in a centrifugal pump used in sewage, the lower edge of the blade plate is largely separated from the surface of the suction cover board to prevent solid matter from clogging. It is unsuitable for pumps used in fresh water because it will cost. [0004] Since the conventional pump casing has a structure in which the axial dimension of the vortex chamber is invariable, when the impeller width is changed, the pump casing is also adjusted accordingly. It is necessary to make a new eddy chamber with a different axial dimension, which causes an increase in cost. Also, it is difficult to change the one designed for sewage to be suitable for fresh water or to remodel the one designed for sewage to be suitable for sewage with the conventional casing structure. An object of the present invention is to provide a centrifugal pump in which the axial dimension of a vortex chamber can be changed according to the width of an impeller to be installed. The second object of the present invention is to greatly separate the suction cover board surface from the lower edge of the blade plate to facilitate the passage of solids when used in sewage, and to use the suction cover board surface when used in fresh water. The purpose of the present invention is to provide a centrifugal pump in which the facing state between the lower edge of the blade plate and the suction cover disk surface is switched according to the application so that the gap between the lower edge of the blade plate and the lower edge of the blade plate is reduced so that the pump performance does not deteriorate. In the centrifugal pump according to the present invention, the outer edge portion of the suction cover is formed as a mounting portion to the lower edge of the peripheral wall of the open bottom pump casing, and one surface of the mounting portion is connected to another portion. Formed on a convex annular surface that protrudes higher than the surface,
An axial dimension of the vortex chamber is increased by fixing one surface of the suction cover to the lower edge of the blade plate to the pump casing, and the other surface of the suction cover is opposed to the lower edge of the blade plate to the pump casing. The axial dimension of the swirl chamber is reduced by fixing. An embodiment will be described below with reference to the drawings. [0008] 1 is a pump casing of an open bottom type,
Reference numeral 2 denotes an impeller fitted to the motor shaft 3 in the pump casing 1, and reference numeral 4 denotes a suction cover facing the lower edge 2e of the blade plate of the impeller 2, and a suction hole 5 is formed at a central portion thereof. The portion is formed as a mounting portion 6 to the lower edge of the peripheral wall of the pump casing 1, and one surface 6a of the mounting portion 6 is formed as a convex annular surface protruding higher than the other surface 6b. Accordingly, when the one surface 4a of the suction cover 4 is opposed to the lower edge 2e of the blade as shown in FIG. 3, the axial dimension of the vortex chamber 7 becomes longer, and
As shown in FIG. 4, the other surface 4b of the suction cover 4 is connected to the lower edge 2e of the blade plate.
, The axial dimension of the vortex chamber 7 is reduced. By any of these states, the mounting bolt 8/8
Is screwed into the screw hole 10 # 10 from the bolt insertion hole 9 # 9, and the suction cover 4 is detachably fixed to the lower edge of the peripheral wall of the pump casing 1. In the embodiment shown in FIG. 3, a pump casing suitable for a centrifugal pump having a large impeller width is formed. In the embodiment shown in FIG. 4, a pump casing suitable for a centrifugal pump having a small impeller width is formed. In any case, a narrow gap G1 is formed below the impeller 2, and the embodiment is suitable for use in fresh water without lowering the pump performance. However, when this is used in sewage, solids are easily clogged in the swirl chamber 7. The suction cover 4 in the embodiment of FIG. 4 is removed and turned over, the other surface 4b of the suction cover 4 is opposed to the lower surface 2e of the blade plate, and the suction cover is re-established in a state where the axial dimension of the vortex chamber 7 is increased. 4 is fixed, impeller 2
A wide gap G2 for passing solids is formed below the vortex chamber, and a pump casing suitable for use in sewage without clogging solids in the swirl chamber 7 is formed. According to the present invention, the size of the swirl chamber 7 in the axial direction is changed to two lengths by a simple operation of simply changing the mounting surface of the suction cover 4, and the blade to be installed is provided. The discharge amount can be changed immediately according to the vehicle width, and it is converted to a state where the pump performance does not decrease when used in fresh water and a state where solid matter is not clogged even when used in sewage. It is also possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional side view of a suction cover in a centrifugal pump according to the present invention. FIG. 2 is a plan view of a suction cover of the centrifugal pump according to the present invention; FIG. 3 is a longitudinal sectional side view of a main part of the centrifugal pump according to the present invention;
An example is shown in which the axial dimension of the swirl chamber is configured to be long according to the width of the impeller to be installed. FIG. 4 is a vertical sectional side view of a main part of the centrifugal pump of the present invention,
An example is shown in which the axial dimension of the vortex chamber is made shorter in accordance with the width of the impeller to be installed. FIG. 5 is a vertical sectional side view of a main part of the centrifugal pump according to the present invention;
An example in which a wide gap for the flow of solid matter is formed below the impeller by selecting the mounting direction of the suction cover will be described. [Description of Signs] 1 Pump casing 2e Lower edge of blade plate 4 Suction cover 4a One surface 4b of suction cover Other surface 6 of suction cover 6 Mounting portion 6a One surface 6b of mounting portion Other surface 7 of mounting portion Vortex chamber

Claims (1)

(57) [Claims for utility model registration] The outer edge of the suction cover (4) is formed as a mounting portion (6) to the lower edge of the peripheral wall of the open bottom pump casing (1), and one surface of the mounting portion (6) is formed. (6a) is formed as a convex annular surface that protrudes higher than the other surface (6b), and one surface (4a) of the suction cover (4) faces the lower edge (2e) of the slat plate to the pump casing (1). By fixing, the axial dimension of the swirl chamber (7) is increased, and the suction cover (4) is fixed to the pump casing (1) with the other surface (4b) facing the lower edge (2e) of the blade plate. A centrifugal pump characterized in that the axial dimension of the vortex chamber (7) is reduced by doing so.