JP3597794B2 - Pump impeller removal tool, pump impeller, pump, and pump impeller removal method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method, a structure and a device for withdrawing an impeller of a positive displacement pump from a drive shaft.
[0002]
[Prior art]
2. Description of the Related Art In general, as a positive displacement pump mainly used for transferring seawater in a marine engine cooling water pump, for example, a pump as shown in FIG. 5 is known. The pump 50 uses a rubber impeller 52 that rotates within a pump housing 51. The impeller 52 is fitted and mounted on the rotary drive shaft 53. In the figure, the pump housing lid member is removed so as to show the impeller so that the inside can be seen. However, during operation, the lid member on the disk is attached to the flange portion 54 on the peripheral edge of the pump housing end, and Is sealed.
[0003]
The impeller 52 has a structure in which an impeller made of rubber having relatively high hardness is fitted around a cylindrical metal bush that is mounted on the rotary drive shaft 53. Although the number of impeller blades varies depending on the size of the pump, it is almost always about 10 blades. The impeller has an outer peripheral edge of the blade abutted on the inner peripheral surface of the pump housing in a resiliently biased manner. The inner peripheral surface of the pump housing is not a cylindrical surface having a perfect circular cross section, but a portion (a certain central angle). (Within a range), the cylindrical surface having a reduced diameter. When the pump is operated, the impeller rotates while changing the amount of deflection by sliding the tip of each blade on the inner peripheral surface of the pump housing, thereby sucking the working fluid from the suction port 55 into the pump housing. Then, the liquid is discharged from the discharge port 56 to the outside of the pump housing.
[0004]
In the pump operated by the above-described operation, the rubber impeller is a consumable item, and is a part that is replaced after an appropriate operation time has elapsed. In order to replace the impeller, the impeller 52 is pulled out from the rotary drive shaft 53 in the axial direction with the cover member of the pump housing removed as shown in FIG. Pumps of this type used in ships are usually installed in very complex, narrow and dark places where piping and various equipment are installed. It is not easy to perform the impeller pull-out operation in such a place. Conventionally, a bifurcated handle portion of a tool such as pliers or pliers is inserted between the blades, and the tool is twisted so that the impeller is gradually pulled out while being rotated around an axis. Such work was possible with relatively small pumps, but large pumps often lacked power and did not pull out.
[0005]
Also, a special tool as shown in FIG. 6 has been developed. The tool 60 has a female screw threaded through the center of the main body 61, and has a T-shaped handle 62 with an external thread that is screwed to the female screw. Two arm members 63 are swingably attached to the main body 61, and the tip ends of the respective arm members 63 are bent inward. Thumb screws 64 are attached to both ends of the main body 61 so as to penetrate the main body 61. The thumb screw 64 is provided such that its tip can contact the side surface of each arm member 63, whereby the spread of both arm members 63 can be restricted.
[0006]
In use, the tool 60 of FIG. 6 loosens both thumbscrews 64 to spread the two arm members 63 at appropriate intervals, and inserts the two arm members 63 between the blades of the impeller 52, and then Then, the two thumb screws 64 are tightened to narrow the gap between the arm members 63, and the tip of the bent end portion of the arm member 63 is hooked on the side surface near the center of the impeller to be gripped. At this time, the T-shaped handle 62 is tightened so that the tip of the male screw portion contacts the center of the end face of the rotary drive shaft 53. When the T-shaped handle 62 is tightened from this state, the tip pushes the end face of the rotary drive shaft 53, and the reaction force causes the main body 61 and both arm members 63 to move toward the near side while the impeller 52 is gripped. Pulled out. The screw tightening force is sufficiently large, and by making the spread of both arm members 63 uniform, a uniform force can be applied to the impeller 52 at an almost axially symmetric position. It can be pulled out smoothly from the rotary drive shaft 53.
[0007]
In addition, as an instrument for pulling out an object from a shaft body by using such a tightening force of a screw, a pulley removing instrument is also well known.
[0008]
The structure of the above-mentioned dedicated tool is relatively complicated for an application only for extracting the impeller of the pump. In addition, it is a very large-scale equipment for use in a very complicated narrow space where piping and various devices are installed, and the handling operation is not simple in consideration of handling in a dark and narrow place. For example, after inserting both arm members, it is preferable that the tightening of both thumb screws is almost equal, but in groping work, it is necessary to check whether both thumb screws have been tightened evenly. Will be difficult. In addition, it is difficult to reliably hold the bent portion of the arm member by hooking the bent portion on the side surface of the impeller. In particular, there is a case where a sufficient gripping force cannot be exerted to pull out the impeller of a large pump.
[0009]
Also, when the number of impeller blades is even, both arm members can be inserted between the blades at 180 ° opposite positions, but when the number of blades is odd, one arm member is If such interference is avoided, the tip of the T-shaped handle cannot abut on the axis of the rotary drive shaft because it hits the blade. As a result, the pull-out force acts on the impeller in a biased manner. If the bias is large, the impeller may not be able to come off easily, or a biased load may act on the rotary drive shaft or the bush to damage them. .
[0010]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned conventional technical problems, and has been devised to effectively solve the problems. Therefore, an object of the present invention is to provide a simple structure and a simple handling operation, which is suitable for use in a small space, and that the screw tightening force acts evenly regardless of the number of impeller blades. And a method and structure for such impeller withdrawal.
[0011]
[Means for Solving the Problems]
An impeller extractor for a pump according to the present invention has the following configuration in order to solve the above-described problems in the related art and achieve the object. That is, an impeller extractor for extracting an impeller mounted on a rotary drive shaft to be rotated in the pump housing from the rotary drive shaft, the inner peripheral end of an impeller opening through which the rotary drive shaft is inserted. And a penetrating female screw formed at a position on the same axis as the rotary drive shaft in a state of being engaged with the inner peripheral end of the impeller opening. It has a main body. Further, a male screw member which is longer than the penetrating female screw of the main body and is screwed to the penetrating female screw is provided. Then, by screwing the male screw member relative to the main body in a state where the main body is engaged with the inner peripheral surface end of the impeller opening, the tip of the male screw member presses the end of the rotary drive shaft. The main body is configured to pull out the impeller from the rotary drive shaft by receiving the reaction force of the pressing force.
[0012]
The impeller of the pump according to the present invention is an impeller mounted on a rotary drive shaft so as to be driven to rotate in the pump housing, and is provided at an inner peripheral surface end of an impeller opening through which the rotary drive shaft is inserted. And an engaging means for engaging the main body of the impeller extractor according to claim 1.
[0013]
Furthermore, the pump according to the present invention can be provided with the impeller according to the second aspect.
[0014]
A method for extracting an impeller of a pump according to the present invention includes using the impeller extractor according to claim 1 to connect the male screw member to the main body in a state where the main body is meshed with an inner peripheral end of the impeller opening. Screw. Thus, the tip of the male screw member presses the end of the rotary drive shaft, and the main body pulls out the impeller from the rotary drive shaft by receiving the reaction force of the pressing force.
[0015]
Further, in another method for extracting an impeller of a pump according to the present invention, an engaging means for engaging the main body of the impeller extracting tool according to claim 1 with an impeller mounted on a rotary drive shaft to be rotationally driven in a pump housing. To form Then, with the main body engaged with the inner peripheral end of the impeller opening, the male screw member of the impeller extractor is screwed into the main body. Thereby, the tip of the male screw member presses the end of the rotary drive shaft, and the main body pulls out the impeller from the rotary drive shaft under the reaction force of the pressing force. This method indicates that the present invention can be applied to an existing pump that does not include the engagement means at the inner peripheral end of the impeller opening by newly forming the engagement means.
[0016]
The engaging means is preferably a screw mechanism or a bayonet mechanism.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a method for extracting an impeller of a pump, an apparatus structure therefor, and an impeller extracting tool according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing an impeller in which an impeller extracting method according to the present invention is performed, and FIG. 2 is a sectional view of the impeller. The impeller 10 has an impeller 12 made of rubber having relatively high hardness around a bush 11 made of metal (preferably, high-strength brass) which is formed in a cylindrical shape so as to be mounted on a rotary drive shaft of a pump. It has an integrally molded structure. The illustrated example has nine blades. Although the structure of the impeller 12 is the same as the conventional one, the bush 11 is longer than the conventional one by several millimeters (about 3 mm). The reason why the bush 11 is lengthened in this way is that the inner peripheral surface of the bush 11 is exposed before the tip of the rotary drive shaft when the impeller 10 is mounted on the rotary drive shaft of the pump, This is for forming a female screw on the inner peripheral surface. As shown in FIG. 2, the entire inner peripheral surface of the bush 11 is splined, but a female screw portion 13 is formed on the inner peripheral surface at one end in the axial direction.
[0018]
FIG. 3 is a front view of the impeller extractor. The impeller extractor 20 basically includes a nut-shaped main body 21 and a bolt-shaped push rod 22, and FIG. 3 shows a state where both are screwed together. The main body 21 is basically formed in a cylindrical shape, and is formed with a female screw that penetrates the center in the axial direction and through which a bolt-shaped push rod 22 can be screwed and inserted. The male screw portion 23 is formed so as to be screwable with the female screw portion 13 on the inner peripheral surface of the bush of the impeller 10 described above. Further, the outer peripheral surface of the main body 21 is subjected to knurling 24 so that when the male screw portion 23 of the main body 21 is screwed into the female screw portion 13 of the impeller 10, it can be easily turned by hand. Further, two parallel flat portions (only one is shown in the figure) are provided at the end of the main body 21 opposite to the end on which the male screw portion 23 is formed so that the end can be gripped with a tool such as a spanner. ) 25 are formed. If necessary, the main body 21 can be turned using a tool such as a wrench to tighten or loosen the main body 21 with respect to the female screw portion 13 of the impeller 10.
[0019]
The push rod 22 can be a regular hex bolt long under the neck. Of course, the head portion may be a horizontal bar of a T-shaped handle or an L-shaped handle.
[0020]
Next, a method of using the impeller extractor 20 will be described. With the cover member of the pump removed as shown in FIG. 5, the main body 21 of the impeller extractor 20 is screwed into the bush 11 of the impeller 10. At this time, the push rod 22 may be screwed into the main body 21 within a range that does not protrude from the end face of the main body 21 on the side of the male screw portion 23 as long as there is no obstacle to the screwing work of the main body. It may be completely separated. When the main body 21 is completely screwed into the bush 11 and fixed, the push rod 22 is subsequently screwed into the main body 21. The tip of the push rod 22 penetrates the main body 21 and abuts on the end face of the rotary drive shaft of the pump. When the push rod 22 is further tightened so as to be screwed in, the axial reaction force is applied to the push rod 22 from the rotary drive shaft. Acts, and the reaction force is transmitted to the main body 21 via a screw engagement between the push rod 22 and the main body 21 due to a bolt-nut relationship. As a result, the main body 21 is screwed on the push rod 22 with the bush 11 of the impeller 10, and the impeller 10 is pulled out from the rotary drive shaft of the pump. After the impeller 10 has been pulled out, the impeller pull-out tool 20 can be removed from the impeller 10 by unscrewing the bush 11 and the main body 21.
[0021]
According to the above-described configuration and operation, the force by which the push rod 22 pushes the rotary drive shaft of the pump acts on the axis of the rotary drive shaft, and the thrust force by which the main body 21 tries to pull out the bush 11 also decreases Works equally around the circumference. Therefore, regardless of whether the number of blades of the impeller 10 is an even number or an odd number, a uniform pulling force can be applied to the impeller 10. Even when the push rod 22 is screwed in, if an existing tool such as a ratchet wrench is fitted to the hexagonal head and used, the push rod 22 can be reliably rotated with a relatively small swing angle of the wrench handle. The impeller 10 can be reliably and smoothly pulled out from the rotary drive shaft of the pump by a simple operation even in a narrow and dark place.
[0022]
FIG. 4 is a front view showing a modification of the main body of the impeller extractor. The main body 31 has external thread portions 33 and 34 having different outer diameters respectively formed on the outer peripheral surfaces of both ends. Since the size of the impeller differs depending on the size of the pump, and therefore the diameter of the bush, the impeller is configured as a main body of an impeller removing tool applicable to two types of impellers.
[0023]
Further, in the example of the above-described embodiment, a screw mechanism is employed as a means for fixing the main body of the impeller extractor to the bush of the impeller, but instead of the screw mechanism, for example, a shaft is provided on the inner peripheral surface of the bush of the impeller. A directional groove and a circumferential groove connected to the directional groove are formed in advance.On the other hand, the end of the main body is axially inserted into the bush, and then the main body is rotated in the circumferential direction. It is also possible to form a partial flange on the outer peripheral surface of the end of the main body so as to engage with the circumferential groove of the bush. In this embodiment, the bayonet mechanism is constituted by both the puller body and the bush. In this case, when tightening the bolt of the push rod of the extraction tool, the partial flange of the main body abuts in the circumferential groove of the bush or cuts in a wedge shape to prevent the main body from rotating so that the main body does not rotate. It is preferable to provide a stopper mechanism for blocking.
[0024]
In addition, a female screw portion can be formed on an inner peripheral surface of the bush of the impeller of an existing pump by post-processing before the impeller is mounted in the pump. By doing so, the puller body shown in FIGS. 3 and 4 can be attached and fixed to the bush, and the impeller can be pulled out as described above.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an impeller in which an impeller extracting method according to the present invention is performed.
FIG. 2 is a sectional view of the impeller of FIG. 1;
FIG. 3 is a front view showing an example of an impeller extractor according to the present invention.
FIG. 4 is a front view showing a modification of the main body of the impeller extractor according to the present invention.
FIG. 5 is a perspective view showing a schematic configuration of a pump that is symmetrical in application of the impeller extracting method according to the present invention.
FIG. 6 is a perspective view showing a conventional impeller extraction tool.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Impeller 11 Bush 12 Impeller 13 Female screw part 20 on the inner peripheral surface of bush 20 Impeller puller 21 Main body 22 Push rod 23 Male screw part 24 on the outer peripheral surface of main body 24 Knurling 25 Flat part 31 Main body 33 Male screw part 34 on the outer peripheral surface of main body Male thread on outer surface of main unit

Claims (5)

An impeller extractor for extracting an impeller mounted on a rotary drive shaft to be rotationally driven in a pump housing from the rotary drive shaft,
It has meshing means (23, 33, 34) which meshes with the inner peripheral surface end of the impeller opening through which the rotary drive shaft is inserted, and further in a state meshed with the inner peripheral surface end of the impeller opening. A main body (21, 31) having a penetrating female screw formed at a position on the same axis as the rotary drive shaft;
A male screw member (22) longer than the penetrating female screw of the main body (21, 31) and screwed to the penetrating female screw;
By screwing the male screw member (22) with respect to the main body (21, 31) in a state where the main body (21, 31) is engaged with the inner peripheral end of the impeller opening, the male screw is formed. A pump wherein a tip of a member (22) presses an end of the rotary drive shaft, and the main body (21, 31) pulls an impeller from the rotary drive shaft by receiving a reaction force of the pressing force. Impeller removal tool. An impeller mounted on a rotational drive shaft to be rotationally driven in a pump housing,
An engaging means (23, 33, 34) for engaging the main body (21, 31) of the impeller extractor according to claim 1 is provided at an inner peripheral surface end of the impeller opening through which the rotary drive shaft is inserted. Characterized by the impeller of the pump. A pump comprising the impeller according to claim 2. The male screw member (22) is attached to the main body (21, 31) in a state where the main body (21, 31) is engaged with the inner peripheral end of the impeller opening using the impeller extractor according to claim 1. The tip of the male screw member (22) presses against the end of the rotary drive shaft, and the main body (21, 31) rotates the impeller by the reaction force of the pressing force. A method for extracting an impeller of a pump, comprising extracting the impeller from a drive shaft. Engaging means (23, 33, 34) for engaging the main body (21, 31) of the impeller extractor according to claim 1 is formed on an impeller mounted on a rotary drive shaft so as to be rotationally driven in the pump housing. In a state where the main body (21, 31) is engaged with the inner peripheral surface end of the impeller opening, the male screw member (22) of the impeller extractor is screwed with respect to the main body (21, 31). Thereby, the tip of the male screw member (22) presses the end of the rotary drive shaft, and the main body (21, 31) pulls out the impeller from the rotary drive shaft under the reaction force of the pressing force. A method for extracting an impeller of a pump.

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