JPS6345518B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure for attaching an impeller to a pump shaft.

For example, conventional examples of single-blade impeller pumps are shown in cross-sectional views including the pump shaft in FIGS. 4, 5, and 6.

In FIG. 4, a step is provided at the end of the pump shaft 1 to expose the axis of the pump shaft 1 and the impeller 2, and an impeller fitting part 3 that fits into the impeller 2 that carries a radial load, It consists of a threaded portion 4 at the end of the shaft that is screwed into the impeller 2, and the threaded portion 4 is oriented toward the impeller 2 when it is rotated in the forward direction for pumping action. In order to prevent foreign matter from entering the impeller fitting part 3 and the threaded part 4, a sealing ring 6 is held down at the inner peripheral corner of the end of the sleeve 5 which is fitted into the pump shaft 1. In such a conventional example, when the impeller 2 is reversed, there is a large possibility that the impeller 2 will loosen from the threaded portion 4 and be pulled out.

In FIG. 5, a key 7 is provided in the fitting part 3 of the pump shaft 1 with the impeller 2, the threaded part 4 protrudes from the through hole of the impeller 2, and a blade retaining nut 8 is screwed into the shaft end. The locking screw 9 is inserted into the hole in the flange part and screwed into the impeller 2 to fix it. However, the axial direction of the impeller 2 is made to stop at the sleeve 5 that fits into the pump shaft 1, and the fitting of the pump shaft 1 is done. A gasket 11 is placed in the stepped portion forming part 3.

In the structure shown in FIG. 5, the torque from the drive machine is transmitted to the impeller 2 by the key 7, and even when rotating in reverse, the rotation stopper screw 9 provided on the impeller nut 8 prevents the impeller 2 from turning. This prevents loosening, so there is no problem when rotating in the forward or reverse direction. Even if the impeller 2 and the impeller nut 8 are processed with care,
With this structure, fine sand and iron powder enter the key 7, the threaded part 4, and the fitting part 3 between the pump shaft 1 and the impeller 2, and during operation, these fine sand and The iron powder acts as an abrasive and damages the area in an extremely short period of time.

In FIG. 6, the impeller 2 is separated into an impeller boss 12 and a side plate 14 with an integrated impeller blade 13, and a tapered pump shaft 1 is connected to the impeller boss 12 via a key 7.
, and screw the vane fixing nut 8 into the threaded part 4 (not visible in the figure) at the shaft end of the pump shaft 1 to fix the pump shaft 1 and the impeller boss 12 . into the impeller boss 12, insert the bolt 16 through the center hole of the side plate 14, and attach the bolt 16 to the pump shaft 1.
It is engraved in the center of the end and fixed by screwing into the internal thread.

This conventional example is effective for forward and reverse rotations, but as described above, fine sand and iron powder can enter and damage the threaded portion and key portion. Additionally, if a part with a large head such as a bolt is provided at the tip of the blade, the vinyl, string, or pulp fibers may get caught in the part in liquids containing vinyl, string, or pulp fibers.

As described above, it can be said that the conventional installation of the pump shaft and impeller is not perfect. The following conditions are necessary to fix the impeller of a pump that pumps a liquid containing fine sand, iron powder, and vinyl, string, and pulp fibers to the pump shaft.

Slurry of sand, iron powder, etc. is applied to key parts, screw parts,
Do not allow it to enter the fitting part between the main shaft and impeller. This is because the pump shaft and impeller rotate at a synchronous speed with the drive machine, but from a microscopic perspective, the main shaft and impeller are in relative motion due to fluctuations in torque. Sand in the parts that are moving relative to each other,
When iron powder enters, it becomes an abrasive and causes damage.

As shown in FIG. 7, which is a longitudinal cross-sectional view including the pump shaft, when the impeller 2 fixed to the pump shaft 1 rotates, the impeller 2 may leak between it and the pump casing 10 if the liquid contains foreign matter such as vinyl, string, or pulp fibers. Even if a non-blocking structure is adopted, foreign matter 17 may block part B in FIG. If a blockage occurs during normal operation, the pump may be temporarily stopped and reversed to clear the blockage. Therefore, it is necessary to have a structure in which the impeller 2 does not come off the pump shaft 1 even if it rotates in the opposite direction.

As a matter of course, it is necessary to ensure that the impeller can be easily installed and removed upon assembly.

In view of the problems of the prior art as described above, the present invention provides a mounting structure for a pump shaft and an impeller that satisfies these conditions and is capable of forward and reverse rotation and is easy to assemble and prevents the entry of minute foreign matter during liquid feeding. The purpose is to

In this invention, a key is interposed between the pump shaft and the impeller boss, or a hole in the pump shaft and the impeller boss is used as a deformed shaft and a hole so that the impeller boss can be moved axially on the pump shaft and not rotated. In a pump shaft and impeller mounting structure in which the side plate with impeller blades is fitted into the impeller boss, a female screw is installed in the center hole of the side plate with impeller blades on the side where the impeller is not provided. A rotation preventing member is provided between the impeller boss and the side plate with impeller blades, and the center hole of the impeller boss is made into a stepped hole, and the small diameter hole of the stepped hole is inserted into the pump shaft insertion portion. The large diameter hole of the step hole is fitted onto the outer periphery of the sleeve that is fitted into the shaft on the base side following the pump shaft fitting part via a sealing ring, and the pump is equipped with a sealing ring between the impeller boss and the side plate with the impeller blades. This is the mounting structure of the shaft and impeller.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view of a pump including an embodiment of the present invention, including the pump shaft, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2.

The discharge casing 18 has a pump casing 1
A nut 21 is screwed into a stud 19 inserted into the discharge casing 18 and fixed thereto. A casing cover 22 is also fitted into the discharge casing 18 and fixed to a stud 23 inserted into the discharge casing 18 by screwing a nut 24. The bearing body 20 is fitted into the casing cover 22 and fixed by a nut 26 screwed into a stud 25 inserted into the casing cover 22.

The pump shaft 1 has a ball bearing 2 fitted into a bearing body 20.
7 and a ball bearing 31 that fits into a bearing housing 28 that fits into the bearing body 20 via a shim 29 . A bearing cover 32 is fitted into the bearing housing 28, and the ball bearing 31 is prevented from moving in the axial direction.
The ball bearing 2 is fixed with a bearing cover 32 and bolts 35 so as not to move in the axial direction.
An oil seal 37 for sealing the pump shaft 1 is fitted into the bearing cover 36 on the 7 side.

The pump shaft sealing portion is provided between the outer periphery of the sleeve 5 that fits into the pump shaft 1 and the casing cover 22. 38 is a gland packing, 39 is a groove ring that guides the leaked liquid to the outside, and the packing retainer 30 that fits into the casing cover 22 has a stud bolt 41 embedded in the casing cover 22 inserted therein, and a nut. 42 is screwed into the stud bolt 41 and propelled to compress the gland packing 38. 43 is a drain ring fixed to the pump shaft 1.

The shaft end of the pump shaft 1 on the impeller 2 side is provided with a step 1a so as to form a fitting part 3 with the impeller 2, and the shaft end is provided with a threaded part 4. The impeller 2 is divided into an impeller boss 12 and a side plate 14 with blades 13 attached.
The small diameter hole 12d of the impeller boss 12 is fitted into the fitting part 3 of the pump shaft 1 via the key 7, the center hole of the boss 12 is a stepped hole, and the large diameter hole 12c has a large diameter. A sleeve 5 is fitted into the outer periphery of the shaft portion adjacent to the pump shaft fitting portion 3 via a sealing ring 44, and is designed to seal the center hole of the boss 12. The large diameter side of the impeller boss 12 is a side plate 14 with blades.
The inner diameter of the fitting part provided on the large diameter part on the fluid outlet side of the impeller boss 12 is fitted into the circumferential groove provided on the large diameter side end surface of the impeller boss 12, and the seal ring 45 is fitted into the circumferential groove provided on the large diameter side end surface of the impeller boss 12. A dead-end female thread is cut in the center of the side without the blade, so that the threaded portion 4 of the pump shaft 1 is engaged therewith. The blade 13 of the side plate 14 with blades at the position where it is fitted with the large diameter side of the impeller boss 12
A hole 46 is drilled in the radial direction from the outer periphery of the large diameter portion on the outlet side of the impeller boss 12.
It is screwed in place. Therefore, impeller boss 1
2, the stepped hole 12b is pressed into contact with the sleeve 5 which extends between the impeller fitting part 3 and the shaft sealing device position with the step 1a of the pump shaft 1 in between, and the sealing ring 45 is also pressed in with the impeller fitting part 3 and the shaft sealing device position. It is crushed by the side plate 14. Impeller 2
The base side is accommodated in the recess of the casing cover 22. A cutout 12a is provided in a portion of the casing cover 22 bordering the recessed portion so that a locking screw 47 can be attached and removed.

Talk about assembly and disassembly. In FIG. 1, when the nut 24 is removed, the pump casing 10, in which the discharge casing 18 and the suction port are made integrally, can be removed from the casing cover 22 while remaining fastened. To disassemble the impeller 2, align the hole 46 with the notch 12a of the casing cover 12, loosen and remove the locking screw 47, and rotate the side plate 14 with impeller blades without rotating the pump shaft 1. 1
The fitting portion of the impeller boss 12 and the side plate 14 with blades is separated. The impeller boss 12 can be removed by pulling it in the axial direction. Assembly is the reverse of the above.

When the pump shaft 1 rotates forward, the threaded portion 4 of the pump shaft 1 tries to tighten further because it is screwed into the side plate 14 with blades, but it cannot be tightened, and the side plate 14 with blades is driven by the threaded portion 4. When the pump shaft 1 is rotated in the opposite direction to remove foreign matter in the pump, the impeller boss is driven from the pump shaft 1 through the key 7, and the impeller boss 1 is driven through the locking screw 47.
2 drives the side plate 14 with blades. Therefore, the impeller 2 will not be separated from the pump shaft 1 during rotation in either the forward or reverse direction.

In the embodiment, a key was inserted between the impeller boss and the pump shaft in order to fit the impeller boss into the pump shaft so that it could move in the axial direction but not rotate. circular, rectangular,
It may also be an irregularly shaped shaft such as a spline.

As described above, according to the pump shaft and impeller mounting structure of the present invention, when the impeller boss is fitted into the pump shaft fitting part through the key, it is possible to reach the shaft sealing position from the impeller fitting part of the pump shaft. Fit the impeller boss and side plate with impeller blades through the seal ring, and screw the female thread of the side plate with impeller blades into the male thread at the end of the pump shaft. The intrusion of iron powder is completely eliminated, and since there are no protruding objects on the outer periphery of the impeller from the inlet side to the outlet side of the blades, the chance of fibers, strings, vinyl, etc. getting caught is reduced. The impeller boss is rigidly attached to the pump shaft so that the side plate with the impeller blades does not move in the axial direction, and the impeller boss and the side plate with the impeller blades are fitted together so that they stop rotating in the axial direction. The installation is strong and cannot be loosened. For forward rotation, the threaded part at the end of the pump shaft is screwed into the large female thread at the center of the side plate with blades, so the rotational force is transmitted directly from the pump shaft to the side plate with blades, and it will not loosen.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is a line A-A in FIG.
4 to 6 are longitudinal sectional views showing a conventional impeller and pump shaft mounting structure, and FIG. 7 is a longitudinal sectional view including the pump shaft, which is an explanatory view regarding reversal. DESCRIPTION OF SYMBOLS 1... Pump shaft, 2... Impeller, 3... Impeller fitting part, 4... Threaded part, 5... Sleeve, 12...
... Impeller boss, 13 ... Impeller blade, 14 ... Impeller side plate, 44, 45 ... Sealing ring, 46 ... Hole, 47
...Stopping screw.

Claims (1)

[Claims] 1. A key is interposed between the pump shaft 1 and the impeller boss 12, or the holes of the pump shaft 1 and the impeller boss 12 are used as irregular shafts and holes.
In the pump shaft and impeller mounting structure in which the side plate 14 with blades is fitted into the impeller boss 12 so as to be movable in the axial direction but not rotated, the side plate 14 with blades is not provided with a blade. Screw the female screw provided in the center hole on the side into the threaded part 4 at the end of the pump shaft 1,
In addition, a rotation preventing member 47 is provided between the impeller boss 12 and the side plate 14 with blades, and the center hole of the impeller boss 12 is made into a stepped hole, and the small diameter hole 12d of the stepped hole is fitted into the pump shaft fitting portion 3. together with the large diameter hole portion 12 of the step hole.
c is a pump shaft and an impeller that are fitted onto the outer periphery of the sleeve 5 which is fitted into the shaft part on the base side following the pump shaft fitting part 3 via a sealing ring 44, and are equipped with a sealing ring between the impeller boss and the side plate with the impeller blades. mounting structure.