JPH02230996A - Centrifugal pump and its impeller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a centrifugal pump and its impeller, particularly to a sand pump type impeller.

[Prior art and its problems] Conventionally, as a means to reduce the axial thrust of a centrifugal pump, as shown in FIG. Those provided with matching holes 2' are known.

However, with this known structure, the pumped liquid discharged from the outlet of the impeller 1' also leaks from the back side of the impeller 1', so compared to an impeller without a balancing hole, the pumped liquid is The disadvantage is that the leakage loss is doubled.

[Object of the Invention] The object of the present invention is to maintain the balance of shaft thrust, reduce leakage loss of pumped liquid, and prevent slurry from going around to the shaft seal, which makes it suitable for use as a sand pump system. The object of the present invention is to provide a centrifugal pump with a suitably improved impeller.

[Summary of the Invention] In the impeller for a centrifugal pump according to the present invention, the impeller is formed by protruding a vane plate on the surface of a base, and a through hole is bored through the impeller from the back side to the surface of the vane plate. It is being

By housing this impeller in the volute chamber, the through-hole opening surface on the back side of the impeller faces the back side wall of the pump casing, and the through-hole opening surface on the impeller surface faces the annular side wall of the suction cover. A pump is constructed.

[Example] In the drawings of the example, 1a is the base of the impeller 1, 1b.
... 1b is a wing plate provided convexly on the surface of the base 1a, I
C...The bow c is a counterbalance blade protruding from the back surface of the base 1a. 2...2 is the blade plate 1 from the back side of the impeller 1
b: A through hole is drilled to penetrate the surface of 1b, 2a is a through hole opening surface on the back surface of the impeller, and 2b is a through hole opening surface on the blade surface.

Reference numeral 3 denotes a spiral chamber in which the impeller 1 is housed. The impeller l housed in the volute chamber 3 has its through-hole opening surface 2a on its back facing the back side wall 4 of the pump casing, and its through-hole opening surface 2b on the vane surface facing the annular side wall 5 of the suction cover. On the other hand, a bypass path is formed: the outer periphery of the impeller 1 → the through-hole opening surface 2a on the back surface of the impeller → the through-hole opening surface 2a → the through-hole opening surface 2b on the blade surface → the outer periphery of the impeller 1.

[Function] When the pump is driven, negative pressure is generated toward the impeller inlet to perform the pumping action, but negative pressure is also generated near the through-hole opening surface 2a on the back of the impeller to maintain the balance of the axial thrust. dripping

[Effect] According to the present invention, due to the effect of the through hole 2 penetrating from the back side of the impeller 1 to the surface of the blade plate 1b, Po 4. When the impeller is driven, a negative pressure is generated in the vicinity of the through-hole opening surface 2a on the back surface of the impeller, so that the balance of the axial thrust is maintained.

Moreover, since the through hole 2 is formed so as to face the annular peripheral wall 5 of the suction cover without facing the pump suction port, there is an effect that leakage loss of pumped liquid is extremely minimized.

Moreover, even if the balancing blade 1c is not provided, it is possible to maintain a sufficient balance of the thrust force.
There is an advantage that C can be omitted to provide a centrifugal pump with less power loss.

Furthermore, in the case of a vertical sand type pump, there is a risk that the earth and sand accumulated on the impeller base will go around to the shaft sealing part, but according to the present invention, the earth and sand that is about to accumulate on the impeller base 1a can be removed. Since the water is allowed to flow down through the through hole 2, there is no chance of it going around to the shaft sealing portion, and it can also perform the protective function of the shaft sealing device.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of the main part of the centrifugal pump of the present invention, FIG. 2 is a longitudinal sectional side view of the main part of the impeller for the centrifugal pump of the invention, and FIG.
A] is a plan view of the impeller for a centrifugal pump according to the present invention as seen from the front side, FIG. 3 [B] is a plan view of the impeller for a centrifugal pump according to the present invention as seen from the back side, and FIGS. Other examples of centrifugal pump impellers are shown, each of which is [
A] is a plan view seen from the front side, and [B] is a plan view seen from the back side. FIG. 6 is a longitudinal sectional side view of a main part of a conventional impeller for a centrifugal pump. 1...Impeller via...Base, 1b...Blade plate, 2...Through hole, 2a...Through hole opening surface on the back of the impeller, 2b...Blade Through holes in the plate surface,
3... Volute chamber, 4... Back side wall of pump casing, 5... Annular side wall of suction cover. Patent applicant: Tsurumi Seisakusho Co., Ltd.

Claims (1)

[Scope of Claims] [Claim 1] An impeller (1) having a blade plate (1b) protruding from the surface of a base (1a) is provided with an impeller (1) that penetrates from the back side to the surface of the blade plate (1b). By drilling the through hole (2) and accommodating the impeller (1) in the vortex chamber (3), the through hole opening surface (2a) on the back side of the impeller is connected to the back side wall (4) of the pump casing.
A centrifugal pump characterized in that the through-hole opening surface (2b) on the surface of the blade plate faces the annular side wall (5) of the suction cover. [Section 2] In an impeller (1) having a blade plate (1b) protruding from the surface of a base plate (1a), a through hole (2) penetrating from the back side to the surface of the blade plate (1b) is provided. By drilling, when the impeller (1) is housed in the volute chamber (3), the through-hole opening surface (2b) on the back surface of the impeller faces the back side wall (4) of the pump casing, and the impeller An impeller for a centrifugal pump, characterized in that a through-hole opening surface (2a) on a plate surface faces an annular side wall (5) of a suction cover.