JPS62197698A - Pump having guide vane - Google Patents

Abstract

PURPOSE:To execute the pump operation in the vicinity of the max. efficiency point by installing a flow-rate adjusting vane between a vane wheel and a guide vane in a fluid flowing passage. CONSTITUTION:An annular fluid flowing passage 11 is formed between a vane wheel 8 and a guide vane 10, and a flow-rate adjusting blade 12 for controlling the discharged water flowing into the guide vane 10 from the vane wheel 8 is installed, positioned between the vane wheel 8 and the guide vane 10. When the pump faculty forms an improper characteristic curve in which the max. efficiency point is shifted to the large flow rate side in the desired characteristic curve for flow rate and efficiency, a part of the inlet a fluid flowing passage 5 is closed by turning the flow-rate adjusting 12. Thus, the position of the max. efficiency point can be adjusted by the manual operation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pump having guide vanes for smoothly flowing fluid sucked in by rotation of an impeller to a discharge portion.

(Prior Art) As a pump having such a guide vane, there is, for example, a support shaft mixed flow pump as shown in FIG. In this pump, a rotating shaft 2 is inserted through the axial center of a pump casing l, and the pump casing l has a discharge bowl la connected to a suction cylinder 3 at its lower end, a lift pipe lb and a discharge curved pipe (not shown). )
The 0-rotation shaft 2, which has a cylindrical shape and is connected to the It is pivotally supported by a bearing 7 so as to be able to rotate around an axis, and rotates when the rotational driving force of a drive device (not shown) is transmitted to the upper end. A single impeller 8 is fixed to the lower end of the rotating shaft 2. A plurality of guide vanes 10 are provided in the flow path 5 to smoothly flow the fluid sucked up from the suction cylinder 3 by the rotating impeller 8 into the lift pipe tb.

(Problems to be Solved by the Invention) In this type of pump, the flow rate-efficiency characteristic curve is as shown by the solid line in contrast to the flow rate-total head characteristic curve shown by the two-dot chain line in FIG. For example, for the flow rate shown by A, the efficiency point near the maximum shown by B is used. However, when the characteristics of the manufactured pump were different from the expected ones, that is, the flow rate-efficiency characteristic curve changed to the seventh
As in the curve shown by the dashed-dotted line in the figure, if the maximum efficiency point shifts to the higher flow rate side than the desired characteristic curve, the efficiency of C, which is lower than the desired efficiency of B for the flow rate of A, may be used. It becomes necessary. In such a case, conventional methods have been used, such as cutting the outer diameter of the blade 8a and grinding the outlet wall thickness negative pressure side of the blade 8a to form a tapered shape, or painting and polishing the blade 8a. is applied to increase the absolute value of the efficiency of C shown in FIG. However, in this adjustment using the blade 8a, although the work is troublesome and takes a long time, the change in the maximum efficiency point toward the small flow rate side is extremely small, and the maximum efficiency point shown by the solid line in Fig. 7 is extremely small. There is a rotational nature that prevents pump operation in the vicinity.

The present invention has been made in view of these problems and to solve them, and provides a pump having guide vanes that can reliably operate the pump near the maximum efficiency point and also allow improvement work to be carried out in a short time. The purpose is to provide the following.

(Means for Solving the Problems) In order to achieve the above object, the pump having a guide vane of the present invention has an annular fluid flow passage provided between the impeller and the guide vane, and a ring-shaped fluid flow passage is provided between the impeller and the guide vane. , a flow rate adjusting vane tip is disposed between the impeller and the guide vanes to control discharge water flowing from the impeller between the guide vanes.

(Function) In the pump having the guide vane of the present invention configured as described above, when the maximum efficiency point shifts to the high flow rate side from the intended position, the guide vane is removed from the impeller by rotating the flow rate adjustment vane. The flow rate guided between the blades can be reduced, and the position of the highest efficiency point can be adjusted to the low flow rate side.

(Example) Hereinafter, a preferred example of the present invention will be described in detail based on the drawings.

In FIG. 1, the same or equivalent parts as in FIG. 8 are given the same reference numerals. In this embodiment, the blades 8a of the impeller 8 are formed slightly shorter than the conventional ones, and an annular fluid flow passage 1 is formed between the impeller 8 and the guide blades 10.
1 is provided in this fluid flow path 11, and is located between the impeller 8 and the guide vanes 10... for flow rate adjustment to control the discharged water flowing from the impeller 8 to the guide vanes 10... Blades 12... are arranged.

The flow rate adjusting blade 12 is connected to a blade body 12 as shown in FIG.
Pivot shafts 12b and 12c are integrally formed at both ends of a, and a screw portion 12d is connected to the lower pivot shaft 12c. In addition, as shown in FIGS. 2 and 4, an upper retainer 13 is prepared, which has a ring shape, and is a support into which the upper pivot shaft 12b of the flow rate adjustment vane 12 is rotatably inserted in the circumferential direction. A plurality of holes 13a... and a plurality of mounting holes (not shown) for fixing to the bearing side 6 with follow bolts (not shown) are formed at equal angular intervals. As shown in FIG. 2, the flow rate adjusting vanes 12 are fitted by fitting the upper pivot shaft 12b into the support hole 13a of the upper retainer 13 fixed to the bearing side 6, and by inserting the upper pivot shaft 12b into the support hole 13a fixed to the discharge bowl la. The lower pivot shaft 1 is attached to the lower retainer 14.
2c is rotatably inserted and supported, and a fixing bolt 15 formed as shown in FIG. Temporarily fix it at an angle that matches the inlet angle, and then, using the test result data, suppose that the maximum efficiency point is as shown by the dashed-dotted line for the desired flow rate-efficiency characteristic curve shown by the solid line in Figure 7. If it is found that the pump performance has an inappropriate characteristic curve that deviates to the large flow rate side, loosen the fixed ring 15 and rotate the flow rate adjusting vane 12 in the direction of the arrow shown in FIG.
The width of the passage area of the fluid guided from one impeller 8 to the guide vane 10 in the fluid flow direction shown by the dashed dotted line in FIG. 5 and FIG. 6, respectively, varies from D shown in FIG.
narrowed down to That is, a part of the inlet of the fluid flow path 5 of the guide vane IO is blocked by the vane body 12a of the flow rate adjusting vane 12.

Therefore, the highest efficiency point is located, for example, 1 point on the high flow rate side from the desired point.
If the deviation is 0%, by adjusting the flow rate adjusting vane 12 to an angle that reduces the passing area of the wave body by 10%, the position of the highest efficiency point will also shift by approximately 10% to the small fii, N side. , the flow rate-efficiency characteristic curve can be approximated from the curve shown by the dashed line in FIG. 7 to the curve shown by the solid line. When the desired pump performance is obtained in this manner, the fixed ring 15 is welded to the lower retainer 14 to prevent rotation, and the angle of the flow rate adjusting vanes 12 is fixed.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various embodiments can be considered based on the scope of the claims. The present invention is not limited to this, and can be applied to other pumps having guide vanes.

(Effects of the Invention) As detailed above, according to the pump having the guide vanes of the present invention, since the flow rate adjusting vanes are provided between the impeller and the guide vanes, the flow rate-efficiency characteristic curve is If the highest efficiency point deviates from the desired position to the high flow rate side, the position of the highest efficiency point can be adjusted by an extremely easy manual operation that changes the vane angle of the flow rate adjustment vane, and the desired flow rate - The desired pump performance can be obtained by quickly approximating the efficiency characteristic curve.

[Brief explanation of drawings]

Figures 1 to 6 show an embodiment of the pump having guide vanes of the present invention, where Figure 1 is a longitudinal sectional view, Figure 2 is an enlarged view of the main part of Figure 1, and Figure 3 is flow rate adjustment. A perspective view of the vane and its fixed ring, Figure 4 is a diagram showing the arrangement of the flow rate adjusting vane, Figures 5 and 6 are explanatory diagrams of the method of adjusting the maximum efficiency point, and Figure 7 is the flow rate adjustment method. FIG. 8 is a longitudinal sectional view of a conventional pump. l... Bonta casing 2... Rotating shaft 3... Suction cylinder 5... Fluid flow path 8... Impeller 10... Guide vane! ! ...Flow path 12...Flow rate adjustment vane Patent applicant: Kubota Iron Works Co., Ltd. Agent
Patent Attorney Takashi Suzue - Figure 1 Figure 2 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] An annular fluid flow path is provided between the impeller and the guide vanes, and a flow rate is provided in the fluid flow path, which is located between the impeller and the guide vanes to control the discharge water flowing from the impeller between the guide vanes. A pump having a guide vane characterized in that an adjustment vane is provided.