JPH11351185A - Canned motor pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a canned motor pump in which bearings are arranged on both sides of an impeller side and an anti-impeller side of a rotor, by using a visible or electric detection method to detect the progress of wear of the bearings. Provided is a canned motor pump which can be monitored reliably and reliably. SOLUTION: In a canned motor pump having a configuration in which bearings 9a and 9b are arranged on both sides of an impeller side and an anti-impeller side of a rotor 5, and an end cover 11 is arranged at an end of the motor section M on the anti-impeller side. The end cover 11 is provided with one or more detection holes 16 opened in the radial direction.
A transparent thick disk 17 is fitted to the end cover 1 and the cover 18 with an open central portion for fixing the disk 17 is attached to the end cover 1.
1 and fixed to the end of the rotor 5 on the side opposite to the impeller, so that the tip of the target 19 is located substantially at the center of the detection hole 16 in the axial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a canned motor pump, and more particularly to a canned motor pump having a bearing wear detector for detecting the progress of wear of a bearing in radial and axial directions.

[0002]

2. Description of the Related Art FIG. 5 is a view showing a general sectional structure of a conventional canned motor pump of this kind. As shown in the figure, an impeller 2 is arranged inside a pump casing 1 of a pump section P, and a casing cover 3 is fixed to an opening on the high pressure side of the pump casing 1. The casing cover 3 is provided with a flow hole 4 for guiding a part of the pumped liquid that has been pressurized after passing through the impeller 2.

[0003] One end of a rotor 5 is inserted into the casing cover 3, and a distance piece (sleeve) 6, a thrust plate 7a, a shaft sleeve 8a, and an impeller fitted to one end of the rotor 5 are fitted thereto. 2 is fixed by bolts 22, and the other end of the rotor 5 is fixed to the thrust plate 7 b and the shaft sleeve 8 b by bolts 23.

The rotor 5 has a pair of bearings 9a at both ends thereof.
The rotor 9 of the motor section M is fixed to a substantially central portion thereof, and a bearing 9a is fitted to the casing cover 3, and a bearing 9b is fitted to the end cover 11 respectively. Also, inside the rotor 5,
A through hole 14 penetrating in the axial direction is formed, and the through hole 14 is open on both sides including bolts 22 and 23 at both ends.

The stator 13 of the motor section M is fitted to a motor frame 24, and frame side plates 25a and 25b are fitted to both ends of the motor frame 24. Further, the can 12a of the rotor 10 of the motor unit M and the can 12b of the stator 13 of the motor unit M protect the rotor 10 and the stator 13 from contact with the pump handling liquid. Further, two sets of magnetic detecting elements S1 and S3 and S2 and S4 are arranged on both end surfaces of the iron core of the stator 13.

In the conventional canned motor pump, the shaft sleeves 8a, 8b and the thrust plates 7a, 7b, which are on the rotating side during operation, are fixed to the bearings 9a, 9 on the fixed side.
In general, the bearings 9a and 9b made of carbon mainly wear due to the rotation while contacting the contact b, and the amount of wear increases with the operation time. Thus, as the wear amount increases with the operation time, the whirling of the rotor 5 increases, and when the wear further advances, the can 12 of the rotor 10
a and the can 12b of the stator 13 begin to come into contact, and the can 12a of the rotor 10 and the can 12b of the stator 13 are damaged, respectively. If the can 12b of the stator 13 is damaged, the stator 1
The pump handling liquid infiltrates the inside of the motor 3 and deteriorates the winding of the stator 13, causing a catastrophic failure of the canned motor body.

Further, since the canned motor pump has a pressure vessel structure integral with the shaft seal between the canned motor and the pump, it is impossible to visually check the whirling of the rotor 5 from outside the main body. Therefore, even if the bearings 9a and 9b are worn out for some reason, such as long-term use or mixing of foreign matter, the change cannot be confirmed from the outside. Therefore, various detecting means for detecting the wear state of the bearings 9a and 9b have been proposed.

Among the detecting means for detecting the wear state of the bearing which has been implemented so far, two sets of magnetic detecting elements S1 are provided on both end surfaces of the iron core of the stator 13 as shown in FIG. There is a detecting means having a configuration provided with S3, S2 and S4. The detecting means detects the wear of the bearings 9a and 9b in the radial direction (radial direction A) by the magnetic detecting elements S1 and S3, S2 and S
The wear in the axial direction (axial direction B) is detected by the magnetic detection elements S1 and S2 or S3 and S4.

As other electrical detection means, a search coil is wound in a winding slot of the stator 13;
Alternatively, there is a detecting means for detecting the wear state of the bearing by using the winding using a canned motor having a special winding structure.

However, in the case of these electric detecting means, the structure of the canned motor itself is complicated and special, which may hinder the manufacture of an inexpensive product, and may be affected by the load fluctuation of the canned motor. It is large, and there is a problem that the wear state is not accurately displayed and reliability is reduced.

On the other hand, as an example of the mechanical detecting means, a mechanical contact portion fixed to the end cover 11 at a fixed distance from the shaft end of the rotor 5 at the shaft end of the rotor 5, There is a detection means having a function of discharging a gas enclosed therein due to contact abrasion. In the case of such a detecting means, once the detecting means has been operated, the gas enclosed therein is released, so it is necessary to replace the detecting means itself together with the worn bearing, thereby increasing the number of maintenance parts. There are problems such as being forced.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in a canned motor pump in which bearings are arranged on both sides of an impeller side and an anti-impeller side of a rotor, wear of the bearings increases. It is an object of the present invention to provide a canned motor pump capable of easily and reliably monitoring the situation by using a visible or electrical detection method.

[0013]

According to a first aspect of the present invention, an impeller is fixed to one end of a rotor, and the rotor is disposed on both sides of the impeller and the impeller. In a canned motor pump supported by bearings, one or a plurality of radially opened detection holes are provided in an end cover fixed to a motor frame side plate, and a transparent thick disk is fitted into the detection holes. Further, a cover with an opening at the center for fixing the disk is provided on the end cover, and the tip of the target fixed to the end of the rotor opposite to the impeller is axially substantially at the center of the detection hole. It is characterized by being arranged so that it becomes.

[0014] The invention described in claim 2 is the first invention.
Wherein the convex lens is fitted to a cover for fixing a disk fitted to the detection hole.

[0015] The invention described in claim 3 is based on claim 1.
Or the canned motor pump according to 2, wherein a sensor for detecting a distance is fixed to a cover lid for fixing a disk fitted to the detection hole, and another detection hole opened in the axial direction is provided on the end cover. A transparent thick disk is fitted into the detection hole, and a cover lid having a central opening for fixing the disk is disposed on the end cover, and the distance between the cover and the target is set to the cover lid. The sensor for detection is fixed.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a configuration example of a canned motor pump according to an embodiment of the present invention. In the basic structure of the canned motor pump itself, the same or corresponding parts as those of the conventional example shown in FIG. 5 are denoted by the same reference numerals, and a duplicate description thereof will be omitted. Hereinafter, the same applies to other embodiments.

As shown in FIG. 1, the bearing 9 on the side opposite to the impeller 2
b is fitted in the bearing holder 15 and the bearing holder 1
5 is an end cover 11 fixed to the frame side plate 25b.
Is fitted. The end cover 11 is provided with one to four detection holes 16 opened in the radial direction, and a transparent thick disk 17 is fitted into the detection holes 16, and the disk 1
A cover 18 having a central opening is provided on the end cover 11 in order to fix the sensor 7, and the projection 19 a at the tip of the cylindrical target 19 is positioned substantially at the center of the detection hole 16 in the axial direction. The target 19 is fixed to the end of the rotor 5 on the side opposite to the impeller 2.

In the canned motor pump having the above-described structure, as the radial wear of the bearings 9a and 9b progresses, the rotor 5 wears in addition to the radial gap where the bearings 9a and 9b are not worn. Large swing by the gap formed. For this reason, the swing width of the target 19 fixed to the rotor 5 increases.

Since the disk 17 is transparent, the deflection of the target 19 can be visually monitored from outside the canned motor pump. However, the run-out of the target 19 is not always equal to the radial wear of the bearings 9a and 9b. This is because, in a sense, the rotor swings indirectly. Therefore, when only the bearing 9a is worn,
Experiments were performed on the case where only the bearing 9b was worn and the case where both the bearings 9a and 9b were worn.
Of the rotor 10 and the can 12 of the stator 13
The maximum value of the run-out of the target 19 when b comes into contact is grasped in advance, and the disk 17 is marked with a margin so as not to make contact.

By doing so, the bearings 9a,
Regardless of how the 9b is worn in the radial direction, the state of wear is surely monitored, and before the can 12a of the rotor 10 of the motor section M and the can 12b of the stator 13 contact and break, By detecting the wear limit of the bearings 9a and 9b,
a or the bearing 9b can be replaced.

In a canned motor pump in which an axial thrust acts on the rotor 5 on the impeller 2 side,
Since the axial wear of the bearing 9a mainly advances, the rotor 5 advances toward the impeller 2 in this case.
On the other hand, in the canned motor pump in which the axial thrust acts on the rotor 5 on the side opposite to the impeller 2, the axial wear of the bearing 9b mainly progresses. Proceed to. Either direction depends on the dimensions of each part of the canned motor pump. Further, even in the same canned motor pump, the direction may be changed by changing the operating point. However, in any case, if the operating point is determined, it becomes one of the two.

Also in this axial direction, when the bearing is not worn, the disc 17 is marked on the disk 17 in accordance with the end face of the target 19 while operating the canned motor pump at a specified operating point. If the bearings 9a and 9b have worn out after a lapse of operation, it can be known which one has worn out. As with the radial wear, the wear of the bearings 9a and 9b is monitored from the outside, and the bearings 9a and 9b are monitored.
b is detected when the wear limit is reached, and the bearing 9a or 9
b can be exchanged. Here, since the disk 17 is made thick, it has sufficient strength against the internal pressure of the pump handling liquid.

FIGS. 2A to 2D are diagrams showing one to four detection holes 16 opened in the radial direction, showing a vertical cross section near the end face of the target 19. FIG. is there. For example, as shown in FIGS.
When one or two detection holes 16 are provided vertically, the bearings 9a, 9
Of the wear in the radial direction b, the wear state particularly in the horizontal direction can be detected. Although not shown, when the number of the detection holes 16 is one or two in the horizontal direction, it is possible to detect a vertical wear state among the radial wear of the bearings 9a and 9b. Further, as shown in FIGS. 2C and 2D, the detection hole 1
6 is one or two in the vertical and horizontal directions, respectively.
Both the horizontal and vertical directions of radial wear of a and 9b can be detected.

FIG. 2E is a view showing a vertical cross section near the end face of the target 19 of the canned motor pump according to the second embodiment of the present invention. As shown, the convex lens 20 is fitted to the cover 18. With such a configuration, in addition to having the effects described with reference to FIGS. 2A to 2D, the presence of the convex lens 20 makes it possible to detect the state of wear more extensively and accurately. FIG. 3 is a sectional view showing a configuration example of the canned motor pump in which the convex lens 20 is provided on the cover 18 of FIG. 2E, that is, the canned motor pump according to the second embodiment of the present invention.

FIG. 4 is a sectional view showing a configuration example of a canned motor pump according to an embodiment of the present invention. As shown in the figure, a sensor 21 for detecting a distance is provided on a cover 18 for fixing a disk 17 fitted in the detection hole 16.
And the sensor 21 detects radial wear of the bearings 9a and 9b. Further, a sensor 22 is provided in the axial direction of the detection hole 16, and the sensor 22 detects axial wear of the bearings 9a and 9b. By adopting such a configuration, it is possible to easily and reliably monitor the progress of wear of the bearings 9a and 9b, similarly to the effect described in the embodiment of the present invention. .

Further, the cable between the sensor 21 and the sensor 22 and the circuit is cut off from the outside air such as a steel pipe between the end cover 11 and the terminal box of the canned motor, so that
It can be used in explosion-proof areas.

[0027]

As described above, according to the invention described in each claim, the following excellent effects can be obtained.

According to the first aspect of the present invention, the end cover is provided with one or a plurality of radially opened detection holes, and a transparent thick disk is fitted into the detection holes. A cover with an open central portion for fixing the disk is disposed on the end cover, and the tip of the target fixed to the end of the rotor opposite to the impeller is located substantially at the center of the detection hole in the axial direction. , It is possible to easily and reliably monitor the progress of the wear of the bearing by using a visible detection method.

According to the second aspect of the present invention, since the convex lens is fitted to the cover for fixing the disc fitted to the detection hole, the state of wear of the bearing can be further enlarged and accurately detected. Therefore, the progress of the wear of the bearing can be more easily and reliably monitored by using a visual detection method.

According to the third aspect of the present invention, a sensor for detecting a distance is fixed to a cover for fixing a disk fitted into a detection hole, and another sensor which is axially opened to an end cover. A detection hole is provided, a transparent thick disk is fitted into the detection hole, and a cover having an open central portion for fixing the disk is disposed on the end cover; Since the sensor for detecting the distance to the target is fixed to the sensor, the progress of the wear of the bearing can be more easily and reliably monitored by using an electrical detection method.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration example of a canned motor pump according to the first aspect of the present invention.

FIG. 2 is a cross-sectional view showing details of a mounting state of a detection hole of the canned motor pump shown in FIG.

FIG. 3 is a sectional view showing a configuration example of a canned motor pump according to the second aspect of the present invention.

FIG. 4 is a sectional view showing a configuration example of a canned motor pump according to the third aspect of the present invention.

FIG. 5 is a sectional view showing a configuration example of a conventional canned motor pump.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pump casing 2 impeller 3 casing cover 4 flow hole 5 rotor 6 distance piece (sleeve) 7 a, b thrust plate 8 a, b shaft sleeve 9 a, b bearing 10 rotor 11 end cover 12 a, b can 13 stator 14 through hole DESCRIPTION OF SYMBOLS 15 Bearing holder 16 Detection hole 17 Disk 18 Cover lid 19 Target 20 Convex lens 21 Sensor 22 Sensor

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomotoshi Hirata 11-1 Haneda Asahimachi, Ota-ku, Tokyo Ebara Corporation (72) Inventor Tomoyuki Yamazaki 4-1-1 Honfujisawa, Fujisawa-shi, Kanagawa Ebara Densan Co., Ltd. (72) Inventor Hironori Ninomiya 4-1-1, Motofujisawa, Fujisawa-shi, Kanagawa Stock Company Ebara Densan Co., Ltd. (72) Takayuki Kuronuma 4-1-1, Motofujisawa, Fujisawa-shi, Kanagawa Prefecture No. Ebara Densan Co., Ltd.

Claims (3)

[Claims] In a canned motor pump in which an impeller is fixed to one end of a rotor and the rotor is supported by bearings arranged on both sides of the impeller and the non-impeller, an end cover fixed to a motor frame side plate is provided. One or a plurality of detection holes opened in the radial direction, a transparent thick disk is fitted into the detection holes, and the end cover is fixed to the end cover. Wherein the tip of the target fixed to the end of the rotor opposite to the impeller is disposed so that the tip of the target is substantially at the center of the detection hole in the axial direction. 2. The canned motor pump according to claim 1, wherein a convex lens is fitted to a cover for fixing a disc fitted to the detection hole. 3. The canned motor pump according to claim 1, wherein a sensor for detecting a distance is fixed to a cover for fixing a disc fitted to the detection hole, and the cover is axially mounted on the end cover. Another open detection hole is provided, a transparent thick disk is fitted into the detection hole, and a cover with an open central portion for fixing the disk is provided on the end cover. A sensor for detecting a distance from the target to the cover;