JPH0727435Y2 - Motor pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a motor pump in which a motor portion and a pump portion are connected to each other through a shaft sealing portion, and in particular, a suction side front shroud (side plate) is lacked and a rear surface is provided. A motor pump that uses a semi-open impeller that has only a shroud (main plate).
It is suitable for use as a submersible motor pump for discharging dirty water and the like.

[Conventional technology]

As shown in FIG. 4, the semi-open impeller has no front-side shroud (side plate) on the suction side and has only a rear-side shroud (main plate) 1a. Conventionally, the impeller 1 is attached to the rear wall of the pump casing 2. Is formed as a vortex pump in which a wide gap a is formed in the front surface of the impeller 1 by retreating to the vicinity of the intermediate casing 3 corresponding to the above. By removing the impeller, wear on the impeller is reduced.

In the pump, the intermediate bracket 3 that supports the impeller-side surface of the shaft sealing device 7 formed of a mechanical seal and the load-side bracket 4 of the motor 6 are fastened together by bolts 8. In the figure, 5 is a main shaft, and 9 is an anti-load side bracket.

[Problems to be solved by the device]

In the above-described conventional motor pump, since the rear shroud 1a of the impeller has no notch, the intermediate casing 3 that supports the impeller-side surface of the shaft sealing device 7 and the load-side bracket 4 of the motor are fastened together. With the bolts 8 attached, they cannot be removed unless they are sufficiently outside in diameter from the rear shroud 1a. Therefore, the pitch of the bolts 8 becomes large, and the parts become large and the cost becomes high. There was a point.

The present invention solves the above-mentioned problems of the prior art, reduces the pitch of the mounting bolts of the member that supports the impeller-side surface of the shaft sealing device, and makes it possible to reduce the size of the member, and to perform disassembly / assembly and oil check. It is an object to provide an easy motor pump.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a motor pump in which a motor portion and a pump portion are coupled via a shaft sealing portion, in which a part of a rear shroud of a semi-open impeller is cut out, and the cutout is formed. It is characterized in that it is set so as to avoid a bolt fastening portion for fastening the load side bracket of the motor and the member supporting the impeller side surface of the shaft sealing portion.

Also, a rubber ring having a hole penetrating both the front and back surfaces or a notch in the outer peripheral portion is inserted into the bolt hole so as to come into contact with the head end surface of the bolt (screw) of the bolt fastening portion. .

[Action]

According to the present invention, as described above, a notch is provided in a part of the rear shroud of the semi-open impeller so as to avoid the bolt fastening part, but when pump is operating, the pumping action of the pump is almost impossible. The liquid to be pumped with little influence is sucked from the suction port on the lower surface of the casing (in the case of a vertical shape), pressurized by the impeller and pumped from the discharge port on the upper surface of the casing.

On the other hand, since the bolt position for fastening the load side bracket of the motor and the member supporting the impeller side surface of the shaft sealing portion is formed so as to correspond to the notch portion of the rear shroud of the impeller, the conventional example As described above, the bolt pitch can be set smaller than that in which the fastening bolt is provided on the outer side of the outer periphery of the rear shroud, and accordingly, the component is miniaturized, and the bolt is not removed without removing the impeller. Since the plug and plug can be attached and detached, it is possible to easily disassemble and assemble, check the oil, and easily check the tightened state of the bolt.

Furthermore, the rear shroud of the impeller has a reduced notch area for the fluid pressure acting on the rear surface of the impeller, so that the axial thrust force acting on the impeller is reduced as in the conventional open blade. It

On the other hand, when the rubber ring is inserted into the bolt (screw) hole so as to come into contact with the head of the tightening bolt (screw), the rubber ring prevents the bolt hole from being clogged with foreign matter, and at the same time, the bolt head. Wear of parts is prevented.

In addition, since the rubber ring has a hole that penetrates both the front and back surfaces in the center portion or has a notch in the outer peripheral portion, the rubber ring and the bolt can be separated from the gap in the peripheral portion of the rubber ring. The liquid pressure that has entered the contact surface with the head can escape from the hole to the impeller side, and there is no pressure difference that acts on both the front and back sides of the rubber ring, so the rubber ring is prevented from coming off. .

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a vertical cross-sectional view of a motor-pump used in water according to an embodiment of the present invention, in which the same reference numerals as those shown in FIG. 4 denote the same or like parts. .

In the figure, a shaft seal device 7 using a mechanical seal is attached to a lower portion of a motor 8, and a semi-open impeller 11 is attached to an end portion of a main shaft 5 extending through the shaft seal device 7. There is no difference from the conventional example (Fig. 4).

In this embodiment, the portion 12a supporting the impeller-side surface of the shaft seal portion 7 constitutes a part of the casing 12,
A semi-open impeller housed inside the casing 12 with a large gap a between the front of the impeller and the casing.
As shown in FIG. 2 (a), the notch 11 is provided with a notch 11 b in the rear shroud 11 a of the impeller 11, and the notch 11 b
When viewed from the impeller 11 side, b is set so as to avoid the tightening bolts 13 that fasten the member 12a supporting the impeller side surface of the shaft sealing portion 7 and the motor load side bracket 4. Has been done.

The tightening bolt (screw) 13 is screwed onto a nut 14 fixed by welding to the load side bracket 4 of the motor 6, as shown in the enlarged cross-sectional view of the main part of FIG. A hole 15a penetrating both the front and back surfaces or a rubber ring 15 having a notch on the outer peripheral portion (not shown) is inserted into the bolt (screw) hole 12b so as to contact the end face of the head 13a of the bolt (screw) 13. There is.

Since it is configured as above, a semi-open impeller
Even if the notch 11b is provided in a part of the rear shroud 11a so as to avoid the fastening part of the bolt (screw) 13, it has almost no effect on the pump pumping action during pump operation. .

On the other hand, the position of the bolt 13 that fastens the motor load side bracket 4 to the member 12a that supports the shaft seal portion impeller side surface is formed so as to correspond to the cutout portion 11b of the impeller rear shroud 11a. Therefore, the bolt pitch can be set smaller than that in the conventional example shown in FIG. 4 in which the fastening bolts 8 are provided outside the outer periphery of the rear shroud 1a, and the motor pump is downsized accordingly.

Further, since the bolt 13 can be attached and detached without removing the impeller, the bolt 13 can be easily disassembled and assembled.
The fastening state of can be easily confirmed. Further, since the rear surface shroud 11a of the impeller 11 has a smaller area for receiving the fluid pressure acting on the rear surface of the impeller by the notch 11b, the thrust in the axial direction acting on the impeller is the same as that of the conventional open blade. Will be reduced.

On the other hand, by the rubber ring 15 inserted into the bolt (screw) hole 12b so as to come into contact with the head of the fastening bolt 13,
It is possible to prevent the bolt hole 12b from being clogged with foreign matter, which hinders the removal of the bolt, and at the same time, to prevent wear of the bolt head.

Further, the rubber ring 15 has a hole 15a which is formed in the central portion by penetrating both the front and back surfaces, or a notch in the outer peripheral portion, so that the contact surface portion with the head of the bolt 13 from the gap in the peripheral portion of the rubber ring 15 is formed. Since the fluid pressure that has entered the chamber can escape to the impeller side, there is no pressure difference acting on both the front and back surfaces of the rubber ring 15, and therefore the rubber ring 15 can be prevented from coming off.

The notch of the impeller rear shroud described above may be set so as to avoid the inlet plug when the oil filling inlet of the shaft sealing device (not shown) is on the same side as the fastening bolt 13.

Further, in the above-described embodiment, an example in which the motor pump is used as a submersible motor pump has been described, but it can be used in a place other than underwater, and can be used in a horizontal shape.

The rubber ring may be an elastic ring.

[Effect of device]

As described above, according to the present invention, the rear shroud of the semi-open impeller is provided with the notch so as to avoid the bolt for fastening the member supporting the lower surface of the shaft sealing device and the lower bracket of the motor. As a result, the following effects are achieved.

(I) In the member that supports the impeller-side surface of the shaft sealing device, the pinch of the bolt that is fastened to the load-side bracket of the motor can be set small, so that the member can be made small and the cost can be reduced.

(Ii) The fastening bolts and the oil filling plug of the shaft sealing device can be attached and removed without removing the impeller from the main shaft, which facilitates disassembly and assembly and inspection of oil. Further, it becomes easy to confirm the tightened state of the bolt.

(Iii) Similar to the conventional open blade, the axial thrust acting on the impeller can be reduced.

Further, a rubber ring is inserted into the bolt hole so that the bracket on the load side of the motor and the member supporting the impeller side surface of the shaft seal portion are fastened to each other, and the rubber ring is inserted into the bolt hole, whereby the bolt is inserted. It is possible to prevent foreign matters from clogging the holes and prevent wear of the bolt heads.

Further, since the hole penetrating both the front and back surfaces of the rubber ring or the notch in the outer peripheral portion eliminates the pressure difference acting on the front and back surfaces of the rubber ring, the rubber ring can be prevented from coming off.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a motor pump showing an embodiment of the present invention, FIGS. 2 (a) and 2 (b) are front and side sectional views of the same semi-open impeller, and FIG. A sectional view and FIG. 4 are vertical sectional views of a conventional motor pump. 4 ... Lower bracket of motor, 5 ... Main shaft, 7 ... Shaft sealing device, 11 ... Semi-open impeller, 11a ... Rear shroud, 11b ... Notch, 12 ... Casing, 12a ... Shaft sealing Surface support member on the impeller side of the device, 12b ... Bolt hole, 13
...... Bolt, 13a ...... Bolt head, 14 ...... Nut, 15 ...
… Rubber ring, 15a …… hole.

Claims (2)

[Scope of utility model registration request] 1. A motor-pump in which a motor portion and a pump portion are connected via a shaft-sealing portion, wherein a rear shroud of a semi-open impeller having only a rear shroud on the suction side is cut out, and a part of the rear shroud is cut out. A motor pump, characterized in that the notch is set so as to avoid a bolt fastening portion that fastens the motor bracket and a member supporting the impeller side surface of the shaft sealing portion. 2. A hole or an outer peripheral portion that penetrates both front and back surfaces of a bolt hole so as to abut against a head end surface of a bolt that fastens a member that supports the impeller-side surface of a shaft-sealing portion of a motor bracket. The motor pump according to claim 1, wherein a rubber ring having a notch is inserted.