JPS63297797A - Impeller of centrifugal pump - Google Patents

Abstract

PURPOSE:To facilitate the machining of an impeller in the caption by forming the side panel of an open type impeller into the shape of an umbrella in which the outer periphery is deflected to the suction side and setting fixedly and integrally blades whose front edges are arranged vertically to the axial center line to the front of the side surface. CONSTITUTION:Respective blades 2 formed projectedly and integrally on the front of the side panel 3 are so formed into a shape of taper that the cross-sectional area of the passage between adjacent blades is approximately uniformalized from the suction 8 side to the discharge side with its width reduced gradually to the outer circumference. After a counter surface 10 along the front edges 2a of the blades 2 is formed as a vertical surface to the axial center line the rear edge 11 is joined to the front edge 13 of a rear end casing 12 as a reference so that the clearance made between the front edge 2a and the counter surface 10 can be uniformalized. Thus, the machining of the portion, where the impeller and the casing face each other, becomes easy.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an impeller for a centrifugal pump.

(Prior art) There are two types of impellers used in centrifugal pumps: a closed type in which the front bridge of the impeller is covered with a side plate, and an open type in which the side plate is provided only on the rear surface of the impeller. The latter type of open-type impeller, which is easy to mold, is used in the pump.

On the other hand, in the above-mentioned open-type impeller, the blades installed on the front side of the side plate are arranged from the suction side to the discharge side. There are vane-shaped types, and the latter type has less flow resistance in the blade passage than the former type because it is designed so that the cross-sectional area of the blade passage is equal from the suction side to the discharge side. It is said that the pump efficiency is high.

By the way, the above-mentioned open type impeller is structurally configured so that one side of the blade passage is divided by the opposing surface of the casing, so there is a space between the leading edge of the blade and the opposing surface of the casing. If the gap formed is too large, liquid leakage will increase and the volumetric efficiency, which is one type of pump efficiency, will be reduced. is formed perpendicular to the shaft, and the blades C are protruded from the front surface of the blades. Therefore, if the blades C provided on the side plate a are tapered blades, the opposing surface d of the casing is also parallel to the blade C. It is necessary to mold it to match the taper, which is extremely difficult to process, and strict processing accuracy is required to make the gap between the leading edge of the blade and the casing uniform from the suction side to the discharge side, which inevitably leads to However, there was a problem in that the production cost increased.

(Purpose) The present invention was made in view of these problems, and its purpose is to provide a new centrifugal pump that is easy to process and manage gaps, and that can maximize pump efficiency. The purpose is to provide impellers.

(Means for Achieving the Object) That is, the present invention provides an impeller for achieving the above object, in which the side plate of an open type impeller is formed into an umbrella shape with the outer circuits facing evenly on the suction side, and the front side of the side plate is In addition, the front fastener has a blade that is perpendicular to the axis and is integrally fixed thereto.

(Example) The details of the present invention will be described below based on illustrated examples.

Fig. 1.2 shows an impeller 1 which is an embodiment of the present invention. ...and supporting the rear tightening of these blades 2...
. . . and a disk-shaped side plate 3 that defines one side of the flow path formed between the two. The blades 2 are formed into an umbrella shape that protrudes forward from the outer periphery, that is, toward the suction port 8 side (FIG. 2), and are integrally formed to protrude from the front surface of the side plate 3. ... are formed in a tapered shape such that the width gradually decreases toward the outer periphery so that the cross-sectional area of the flow path between them is almost equal from the suction port 8 side to the discharge side, and each of these front fasteners 2a... is formed perpendicular to the axis.

FIG. 2 shows a centrifugal pump incorporating the impeller 1 formed in this way.The front casing 7 that covers the front surface of the impeller 1 is provided with a suction port 8 and a discharge port 91Fr, as well as an impeller. 2..., the opposing surface 10 along 2a... is formed as a plane perpendicular to the axis, and then the tightening 11 is formed there with reference to the front edge of the rear casing 12. By joining the blades 2 to In the figure, reference numeral 14 indicates a motor, and 15 indicates a mechanical seal interposed between the inner surface of the rear casing 12 and the rear end of the impeller 1.

Therefore, the impeller 1 and the front casing 7 are formed by casting or the like.
After forming, if the front tightening 2a and the opposing surface 10 of the blade 2 are each ground flat using a processing machine, there will be a necessary minimum distance between the front tightening 2a of the blade 2 and the opposing surface 10 when assembled as a pump. The gaps 6 of this size are uniformly formed over the entire surface.

Note that since the side plate 3 of the impeller 1 is umbrella-shaped, the gap between it and the rear casing 12 becomes large, but since the back surface of the side plate 3 is a closed chamber, the volumetric efficiency is not reduced.

(Effects) As described above, according to the present invention, the side plate of the impeller is formed into an umbrella shape, and the tapered blade is integrally fixed to the front surface of the side plate so that the front fastener is perpendicular to the axis. Therefore, not only is it extremely easy to process and control the dimensions of the opposing parts of the impeller and casing, but also the gap between them can be made uniform over the entire surface and as small as possible. pump efficiency can be significantly improved.

[Brief explanation of the drawing]

Fig. 1 (aXb) is a side view and a front view of an impeller showing an embodiment of the present invention, Fig. 2 is a sectional view of a centrifugal pump equipped with this impeller, and Fig. 3 is a sectional view of a conventional centrifugal pump. It is a diagram. 1... Impeller 2... Vane 2a...
... Front tightening 3 ... Side plate 7 ... Front casing 10 ... Opposing surface 12 ... Rear casing

Claims (1)

[Claims] An impeller in which the side plate of an open type impeller is formed into an umbrella shape with the outer peripheral edge biased toward the suction side, and a blade whose front edge is perpendicular to the axis is integrally fixed to the front surface of the side plate. .