JPS6164992A - Submersible pump for excavator - 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 (a) Industrial field of application The present invention relates to a submersible pump for an excavator such as a reverse circulation drill. (b) Conventional technology An example of a submersible pump for an excavator is shown in FIG. This will be explained using the reverse circulation drill shown in the figure below as an example. Reference numeral 1 denotes a base installed on the ground, and a rotary table 2, which is an excavation torque supply device, is fixed on the base 1. A Kerry bar 3 is engaged with the center of the rotary table 2 so as to be able to receive drilling torque as the rotary table 2 rotates. 5. Stabilizer 6
, a submersible pump 7, and a bit 8. In the example shown, the submersible pump 7 is a pump unit with a stabilizer. A swivel joint 9 is connected to the upper part of the Kelly bar 3, and a hydraulic rotary joint 10 is connected to the upper part of the swivel joint 9, and a hydraulic hose 12 is connected to the hydraulic pump unit 11 installed on the ground. The pressure oil supplied through the submersible pump 7 is guided to the submersible pump 7. A suspension 9a is attached to the swivel joint 9, and a drill string including the swivel joint 9 and up to the bit 8 is suspended from a crane 121. A suction port is located at the center of the lower end of the bit 8, and the excavated earth and sand is sucked up together with water by the submersible pump 7, passes through the inner cylinder of each drill, and is connected to the delivery hose 13 attached to the swivel joint 9. It is discharged to the settling tank 14 via the water. The supernatant liquid is then sucked up by the circulating water supply pump 15 and returned to the borehole. By repeating this process, a pit is excavated.

The detailed structure of the conventional submersible pump 7 described above will be explained with reference to FIGS. 4 and 5. A circular casing 17 is arranged in the center, and the bit 8 is connected to the lower part of the casing 17 via a suction casing 16. Inside the casing 17.

An impeller 18, to which two blades 18a are attached, is fixed to a drive shaft 191 of a hydraulic motor (not shown) so that large chunks of earth and sand can pass through. The drive shaft 19 is supported by a lower housing 23 via a bearing 22 and an upper housing 24 via a bearing (not shown), and the lower housing 23 is fixed to the casing 17.

The casing 17 is provided with one discharge port 17a in order to prevent clogging with earth and sand due to a decrease in flow velocity. The discharge port 17a is connected to a discharge pipe 25 leading to the stabilizer 61, and a flange 17b1 located symmetrically to the symmetrical discharge port 17a is connected to a weight balance pipe 26 of Cl2O.

21 is a seal that prevents muddy water from entering the bearing 22.

In the conventional submersible pump configured as described above, as shown in FIG. 4, the discharge port 17a of the casing 17 extends in the tangential direction of the casing 17. The dimensions are larger than the outside diameter. For this reason, in FI#1, which excavates a vertical hole with a circular cross section, the entire submersible pump rotates, so the minimum hole diameter that can be excavated is determined by adding l to the maximum diameter of the submersible pump. Therefore, in order to excavate a hole with a smaller diameter, it is necessary to relatively reduce the outer diameter of the casing 17, and accordingly, the outer diameter of the impeller 18 must also be reduced. As mentioned above, the submersible pump for an excavator conveniently uses an impeller 18 with a large suction and inlet diameter and two blades 18a so that a large lump of earth and sand can pass through. However, if the outer diameter of the impeller 18 is made smaller, the length of the blades at the other end becomes shorter due to the structure, resulting in a disadvantage in that the pumping capacity and efficiency of the submersible pump are reduced.

(C) Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned problem 1, and its purpose is to reduce the diameter of the submersible pump casing without reducing its outer diameter. An object of the present invention is to provide a submersible pump for an excavator that can excavate a vertical hole.

(d') Means for Solving the Problems In order to achieve this object, the present invention has a circular casing having a suction port in the center, and the discharge port is located along the outer circumference of the casing, and the impeller is driven. It is characterized by being formed so that it can be taken out by bending in the axial direction.

(e) Example Hereinafter, an example of the present invention will be described in more detail with reference to FIGS. 1 and 2. 1 and 2, the same reference numerals as in FIGS. 4 and 5 represent the same or equivalent elements. circular casing 2
At the center of the interior of 7 is an impeller 1 having two blades 18a.
8 is provided.

The impeller 18 is connected to the bit 8j via the suction casing 16 on the drive shaft suction side of a hydraulic motor (not shown), and is provided at only one location on the discharge port side to prevent clogging with earth and sand due to a decrease in flow velocity. One discharge port 27a is formed along the outer periphery of the casing 27 and can be taken out by bending the drive shaft 19 of the impeller 18 once in the axial direction. Therefore, as shown in FIG. 1, the flow path leading to the discharge port 27a extends beyond the outer diameter of the casing 27 so as not to protrude further. Furthermore, in order to reduce pressure loss, the flow path to the discharge port 27a is smoothly curved.

Since the maximum diameter of the submersible pump is set to be the same as the outer diameter of the circular casing 27, the minimum hole diameter that can be excavated is equal to the outer diameter of the circular casing 27.

This is determined by this. Therefore, it is possible to excavate a vertical hole with a small diameter corresponding to that amount. Kong name & hl
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It becomes possible to drill small holes without IF.

Additionally, since there is no need to reduce the outer diameter of the impeller, there is also the advantage that the performance of the submersible pump does not deteriorate.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention,
FIG. 1 is a plan view showing the casing of the submersible pump. FIG. 2 is a partially sectional side view of the submersible pump. FIG. 3 is an overall side view showing the state in which a pit is being excavated by the excavator according to the present invention, and FIGS. 4 and 5 are FIGS. 1 and 2 showing the conventional submersible pump structure. It is a figure equivalent to the figure. 8...bit, 18...impeller, 19...,
Drive shaft, 25...Discharge pipe, 2711 circular casing, 27amII discharge port ＼ Agent Patent attorney Teruo Tomita -°′・ Figure 1 Figure 4

Claims (1)

[Claims] 1. A submersible pump for an excavator, characterized in that a discharge port of a circular casing having a suction port in the center is formed so as to be taken out by bending along the outer periphery of the circular casing and in the direction of the drive shaft of an impeller.