JPS6357638B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a canned motor pump that can be assembled by press forming steel plates and welding as appropriate.

In general, pumps used in small-sized absorption refrigerators are required to be small, have excellent sealing properties, be easy to install, and have a highly durable structure that requires no maintenance. Therefore, in the event that a pump malfunctions, it is necessary to replace it with a new one. Therefore, it is desirable to be able to provide an inexpensive pump that can reduce manufacturing costs.

In order to satisfy the above-mentioned requirements for conventional canned motor pumps, various proposals have been made, for example, to assemble the external casing and impeller of the canned motor pump with press-formed steel plates. In order to establish the lubrication and cooling functions and the thrust balance function of the bearing, there is a limit to the structural simplification, and the simplification of only a very partial structural part is not satisfactory.

Therefore, the inventors of the present invention have conducted various studies and made prototypes in order to overcome the above-mentioned problems of the canned motor pump all at once.
The motor internal casing (acts as the stator can and rotor casing), the pump casing, and the partition plate between the motor section and the pump section are each made of press-formed steel plates, and these are joined and assembled by welding as appropriate to form the entire structure. It has been found that the method can be simplified and manufactured easily, and the above-mentioned problems can be solved at once.

That is, in this case, the motor internal casing is integrally formed by drawing, the motor rotor is rotatably housed therein via a bearing, and the rotor shaft is projected from one end opening side of the motor internal casing. Further, the motor outer casing is also integrally formed by drawing processing, and the motor stator is fixedly disposed on the inner circumferential portion, and the motor inner casing is inserted and disposed in the center of the interior. Furthermore, the pump casing is formed by punching out the suction port and the discharge port, and forming the entire body into one piece by drawing, and attaching the impeller to one end of the rotor shaft, and sealing the open end of the motor casing with a partition plate as appropriate. Then, the motor casing and the pump casing are abutted against each other at their peripheral edges and welded together. Then, a suction pipe and a discharge pipe are welded to the suction port and discharge port of the pump casing, respectively. In this way, the canned motor pump can be assembled extremely easily.

In particular, in a canned motor pump configured as described above, when the motor rotor is rotatably housed together with a pair of bearings in the motor internal casing, the outer periphery of the motor rotor is surrounded by a rotor can, and rotor end cover plates are attached to both ends of the motor rotor. By installing this, the motor rotor can be reliably sealed, and if one end of each bearing is directly opposed to the rotor end cover plate and acts as a thrust washer, a balancing action against the shaft thrust can be easily achieved. I figured out what I could do.

Therefore, an object of the present invention is to divide the casing of each part into a very small number of parts, each of which is integrally molded with a steel plate, to facilitate the assembly of the motor component and pump component, and to make it possible to easily assemble the motor component and the pump component. To provide a canned motor pump that is easy to handle, inexpensive, and can be used as a disposable type without impairing its function as a pump.

In order to achieve the above object, the present invention provides a motor outer casing formed by drawing a steel plate into a cylindrical cup shape, and a motor formed by drawing a steel plate into a cylindrical cup shape having a smaller diameter than the motor outer casing. Consisting of an internal casing, a pump casing in which a steel plate is drawn, a suction port and a discharge port are punched out, and a suction pipe and a discharge pipe are welded to these, and a press-formed steel plate for sealing the motor internal casing. The motor stator is sandwiched and fixed between the cylinders of the motor outer casing and the motor inner casing, and the motor rotor is placed inside the motor inner casing with a pair of front and rear partition plates having a diameter slightly larger than the outer diameter of the motor rotor. The rotor shaft is housed in the pump casing along with a bearing, and the rotor shaft is supported by each of the bearings, and one end of the rotor shaft extends through the partition plate and into the pump casing, and the impeller is connected to the pump casing. A rotor end cover plate composed of an annular body having a dish-shaped cross section is provided at both ends of the enclosed motor rotor, and the rotor end cover plate is fitted and fixed between the rotor can and the motor rotor shaft, and is opposed to the dish-shaped recess of the rotor end cover plate. one end of each bearing is made to protrude so that it can be contacted, and a slit is provided on the protruding end surface, the rotor end cover plate is configured to act as a thrust washer for thrust balance, and the partition plate is arranged to extend through the opening of the motor internal casing. The motor outer casing, the motor inner casing, and the pump casing are integrally welded to each other.

In the above-mentioned canned motor pump, a liquid passage hole is drilled in a part of the partition plate to introduce a part of the pump handling liquid into the motor internal casing, and a liquid passage hole is bored in each of the pair of front and rear bearings. However, it is preferable that a liquid storage chamber is provided at the rear end of the rotor shaft, and a through hole is provided in the rotor shaft, which is opened at one end of the pump casing to form a circulation system for the liquid handled by the pump.

Next, typical embodiments of the canned motor pump according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a motor outer casing, and 12 indicates a pump casing. The motor outer casing 10 is integrally formed into a cylindrical cup shape by drawing a steel plate, and the motor stator 14 is fixedly disposed on the inner circumference thereof. The opening end edge of this motor outer casing 10 is provided with a flange portion 16 directed slightly outward. In addition, motor external casing 1
An insertion hole 20 for inserting the power supply cable 18 of the motor stator 14 is provided in the center of the closed end surface portion on the opposite side of the motor stator 14 . Motor stator 1
A motor inner casing 22, which functions as a stator can and a rotor casing, is inserted into the motor outer casing 10 in which the motor 4 is disposed. Similarly to the motor outer casing 10, the motor inner casing 22 is constructed by integrally forming a steel plate into a cylindrical cup shape by drawing.
In this case, the opening end edge of the motor inner casing 22 is provided with an outward flange portion 24 having approximately the same diameter as the outer diameter of the flange portion 16 of the motor outer casing 10 . By configuring the motor inner casing 22 in this way, the motor outer casing 10
The opening end of the motor is closed by an outwardly directed flange 24 of the motor inner casing 22 . On the other hand, the pump casing 12 is integrally formed by punching a suction port 26 and drawing into a substantially lid-like shape, and a discharge port 28 is suitably formed in the peripheral surface. Further, the opening end of the pump casing 12 is configured to have the same diameter as the opening end of the motor outer casing 10, and the opening end edge has an outward direction of the same diameter as the outside diameter of the flange portion 16. Flange part 30
will be established. In this way, by aligning the open ends of the motor outer casing 10, motor inner casing 22, and pump casing 12, and welding and joining the respective flanges 16, 24, and 30, a canned motor pump is completed. can do. A suction pipe 32 is suitably welded to the suction port 26 of the pump casing 12, and a discharge pipe 34 is welded to the discharge port 28 to facilitate connection with the fluid system.

Note that when welding the motor outer casing 10 and the pump casing 12, each flange portion 1
6 and 30, the opening ends are butted together, and the motor internal casing 2
It is also possible to weld and join the two flange portions 24 while holding the end edges thereof (see FIG. 2).

Next, the internal structures of the motor section and pump section of the pump according to the present invention will be explained in detail. Inside the motor internal casing 22 are a pair of front and rear bearings 3.
The motor rotor 40 is rotatably housed together with the motor rotors 6 and 38. In this case, the outer diameters of the bearings 36 and 38 are configured to be larger than the outer diameter of the motor rotor 40, and grooves (not shown) are formed in the outer peripheral surfaces of the bearings 36 and 38 in the axial direction, respectively. Press fit into the motor internal casing 22. As a result, the motor inner casing 22 tightly surrounds both the bearings 36, 38, so that rotation of the bearings can be prevented. Moreover,
Even when the motor internal casing 22 has a thin structure, it is possible to easily assemble the motor and maintain sufficient strength of the casing 22.

Further, in both the bearings 36 and 38, a large number of liquid passage holes 44 are formed in parallel with the rotor shaft 42, and liquid passage grooves 46 are carved in the inner peripheral surface in contact with the rotor shaft 42. On the other hand, the motor rotor 40 has an outer circumference surrounded by a rotor can 48 and an annular end cover plate 5 having a dish-shaped cross section on both front and rear end surfaces.
0 and 52, respectively, and the motor rotor 40 is sealed. In this case, the end cover plate 5
Both end surfaces of the bearings 36 and 38 facing the bearings 0 and 52 are made to protrude so as to be able to come into contact with the dish-shaped recesses of the end cover plates 50 and 52, and each of the protrusions 56 is provided with a slit 54, so that when the axial thrust of the motor rotor is generated, the ends cover plate 50,
52 can act as a thrust washer for thrust balance. Note that the rear bearing 38 is fixed in contact with the end of the motor internal casing 22 and defines a liquid reservoir chamber 58 in the center of the end that communicates with the liquid passage hole 44 . On the other hand, the front bearing 36 is fixed to the opening of the motor inner casing 22 by a circular partition plate 62 having a boss portion 60 in the center. In this case, the circular partition plate 62 has its outer peripheral surface properly fixed to the flange portion 24 of the motor internal casing 22, and an inward flange portion 64 is formed at the tip of the boss portion 60, and this flange portion 64 is attached to the front bearing 36. Abuts on the inner peripheral edge of the end face. As a result, the motor rotor 40 including the bearings 36 and 38 can be stably and firmly fixed within the motor inner casing 22 with some elasticity generated in the partition plate 62.

In this way, the inflator 66 is pivotally attached to the tip of the rotor shaft 42 protruding from the boss portion 60 of the partition plate 62 from inside the canned motor defined by the partition plate 62, and the pump casing is mounted on the inflator 66. 12 and weld and join each casing as described above, the canned motor pump according to the present invention can be completed. In addition, in the pump of the present invention, a part of the handling liquid is introduced into the canned motor section to cool the motor section and to cool the bearing 3.
In order to lubricate the rotor shafts 42 and 6, 38, a large number of liquid holes 68 are bored along the circumferential direction in the partition plate 62 located on the back surface of the impeller 66 to introduce a portion of the liquid to be handled. A through hole 70 for discharging the introduced liquid is bored in the center of the tube. Note that it is preferable to provide a filter in the liquid passage hole 68 of the partition plate 62 as appropriate.

The operation of the pump according to the present invention having the above-mentioned configuration will be explained as follows. The motor rotor 40 and impeller 66 rotate simultaneously due to the bias of the motor section, and the pump handling liquid is sucked into the pump casing 12 through the suction pipe 32 and discharged through the discharge pipe 34. At this time, a part of the handling liquid sucked into the pump casing 12 is transferred to the motor inner casing 22 through the liquid passage hole 68 provided in the partition plate 62.
be introduced within. The handling liquid thus introduced into the motor internal casing 22 flows into the gap between the motor rotor 40 and the end cover plate 50 through the liquid passage hole 44 and the slit 54 of the bearing 36, where a portion of the liquid flows into the gap between the motor rotor 40 and the end cover plate 50. The handling liquid flows through the bearing 3 through the liquid passage groove 46 of the front bearing 36.
6 is circulated to the pump section through the shaft penetration gap of the partition plate 62. Additionally, most of the liquid cools the motor section through the gap between the rotor can 48 of the motor rotor 40 and the motor internal casing 22, and cools the motor section through the liquid passage hole 44 of the rear bearing 38.
It then reaches the liquid reservoir chamber 58 while lubricating the bearing 38 via the liquid passage groove 46. In this way, the handled liquid that has reached the liquid reservoir chamber 58 is circulated to the pump section via the through hole 70 of the rotor shaft 42.

As is clear from the embodiments described above, according to the pump of the present invention, the main surface component of the motor section is held by the motor inner casing which is integrally formed by drawing a single steel plate. The motor rotor, which is housed in the motor internal casing together with the bearings, can be reliably sealed by surrounding its outer periphery with a rotor can and by attaching rotor end cover plates to both ends. Therefore, the rotor end cover plate can act as a thrust washer to balance the shaft thrust by opposing one end of the directly opposing bearing. Therefore, thrust balance can be achieved with a simple configuration without the need for a special thrust washer as in the prior art.

In addition, among the members each made of steel plate,
The partition plate is welded to the opening of the motor internal casing to seal it and at the same time achieve elastic retention of the bearing, and the opening edges of the motor external casing, motor internal casing, and pump casing are integrally formed. By welding and joining, a disposable canned motor pump can be manufactured at low cost.

The canned motor pump according to the present invention has an extremely simple structure and is easy to assemble, so it can be manufactured at a low cost. It has many excellent features such as the ability to smoothly lubricate bearings, and its application fields are extremely wide.

Although the preferred embodiments of the present invention have been described above, the pump of the present invention is not limited to the above-described embodiments, and can be applied to various other pumps as well. Of course, various design changes can be made within the scope.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a canned motor pump according to the present invention, and FIG. 2 is a sectional view of essential parts showing another embodiment of a welded joint structure between a motor outer casing and a pump casing. 10...Motor external casing, 12...Pump casing, 14...Motor stator, 16...
...Flange part, 18...Cable, 20...Insertion hole, 22...Motor internal casing, 24...Flange part, 26...Suction port, 28...Discharge port, 3
0... Flange portion, 32... Suction pipe, 34... Discharge pipe, 36... Front bearing, 38... Rear bearing, 40... Motor rotor, 42... Rotor shaft, 44... Liquid hole, 46 ...Liquid passage groove, 48...
...Rota can, 50, 52...End cover plate, 54...Slit, 58...Liquid storage chamber, 6
0...Boss part, 62...Circular partition plate, 64...Flange part, 66...Impeller, 68...Liquid hole,
70...Through hole.

Claims (1)

[Scope of Claims] 1. A motor outer casing formed by drawing a steel plate into a cylindrical cup shape, a motor inner casing formed by drawing a steel plate into a cylindrical cup shape having a smaller diameter than the motor outer casing, and a steel plate formed into a cylindrical cup shape. It consists of a pump casing which is drawn and punched with a suction port and a discharge port, and a suction pipe and a discharge pipe are welded to these, and a partition plate made of a press-formed steel plate for sealing the motor internal casing. , a motor stator is sandwiched and fixed between the cylinders of a motor outer casing and a motor inner casing, and a motor rotor is housed in the motor inner casing together with a pair of front and rear bearings having a diameter slightly larger than the outer diameter of the motor rotor; Both ends of the motor rotor are configured such that rotor shafts are respectively supported by the bearings, one end of which extends through the partition plate and into the pump casing, and an impeller is coupled thereto, the outer periphery of which is surrounded by a rotor can. A rotor end cover plate constituted by an annular body having a dish-shaped cross section is provided in the section, and this is fitted and fixed between the rotor can and the motor rotor shaft, and one end of each bearing is provided opposite to the dish-shaped recess of the rotor end cover plate. The rotor end cover plate is configured to protrude so that it can be contacted and a slit is provided on the protruding end surface so that the rotor end cover plate acts as a thrust washer for thrust balance, and the partition plate is welded to the opening of the motor internal casing. A canned motor pump characterized in that the opening end edges of the motor outer casing, the motor inner casing, and the pump casing are integrally welded together. 2. In the canned motor pump according to claim 1, a liquid passage hole for introducing a part of the pump handling liquid into the motor internal casing is formed in a part of the partition plate, and a pair of front and rear bearings are provided. A liquid passage hole is formed in each of the holes, a liquid storage chamber is provided at the rear end of the rotor shaft, and a through hole is provided in the rotor shaft, which is opened at one end of the pump casing to form a circulation system for the liquid handled by the pump. A canned motor pump consisting of: