JPH02196191A - Electric motor driven pump - Google Patents

Abstract

PURPOSE:To suppress any temperature rise in the whole of an electric motor during its use so as to make it possible to prevent lowering of an operation load by allowing a part of water discharged from a pump impeller blade to flow through a ring passage and an axial passage to circulate to the pump impeller blade again. CONSTITUTION:When a rotor 7 is rotated by the magnetic field of a stator 8, rotating force causes the rotation of a coupling body 16 to be transmitted to a pump impeller blade 16b. At this time, water is sent under pressure from a suction hole 2a to a discharge hole 2b by the pressure generated by the rotation of the impeller blade 16b. In addition, a part of the water discharged from the impeller blade 16b is allowed to flow in a ring passage 19 from the rear of the impeller blade 16b to enter an axial passage 20 through a space between a thrust bearing 18b and a bearing 17b and a space between the bearing 17b and a fixed shaft 15 from the rear of the coupling body 16. Furthermore, the water is allowed to flow between a bearing 17a and the fixed shaft 15 and between a thrust bearing 18a and the bearing 17a to circulate to the impeller blade 16b again. Since the inside of an electric motor and a bearing part are always cooled by a part of the water circulated as mentioned above, the temperature rise inside the motor can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application 1] The present invention relates to an electric pump device in which a stator is water-sealed within a casing by a can located on the inner peripheral surface of the stator.

[Prior Art] FIG. 5 is an axial cross-sectional view showing a conventional electric pump device of this type disclosed in, for example, Japanese Utility Model Publication No. 49-11855. In the figure, (1) is a casing, which is composed of a cylindrical intermediate casing (1a) and end casings (lb) and (lc) fitted into openings at both ends of the intermediate casing (1a). (2a) and (2b) are a water inlet and a water outlet provided in the end casing (lb), and (3) is a water inlet and a water outlet provided in the end casing (lb); Inside the pump room (IA)
and the motor chamber (IB), (4) is the end casing (IC) and the bracket (3), each bearing (
a rotating shaft rotatably supported by 5a) and (5b);
(6) is a pump blade fixed to the end protruding into the pump chamber (IA) of the rotating shaft (4), (7) is a rotor fixed to the middle of the rotating shaft (4), and (8) is a stator located on the outer periphery of the rotor (7) and fixed to the intermediate casing (1a);
(9) is an ultra-thin stainless steel can disposed on the inner peripheral surface of the stator (8), which seals the stator (8) in the casing (1) with water. (10a), (1
0b) is an O-ring interposed between the can (9) and the bracket (3) and between the can (9) and the end casing (1c).

Next, the operation will be explained. When the rotor (7) rotates due to the magnetic field generated in the stator (8), this rotational force is transmitted to the pump blades (>4) via the rotating shaft (4).

At this time, the water is forced from the water inlet (2a) to the water outlet (2b) by the pressure generated by the rotation of the pump blade (6). Further, a portion of the water discharged from the pump blade (6) enters into the can (9) through the gap between the rotating shaft (4) and the bearing (5a).

[Problem to be solved by the invention] In the conventional electric bomb device as described above, the can (9
) Since there is no outlet for the water that has entered the can (9), the water temperature rises in the can (9), raising the temperature of the entire motor and reducing the operating load. This invention solves this problem. The object of the present invention is to obtain an electric pump device that can prevent a decrease in operating load by suppressing the temperature rise of the entire motor during use.

[Means for Solving the Problems] In order to achieve the above object, an electric pump device according to the present invention is provided in which a stator is water-sealed in a casing by a can located on the inner peripheral surface of the stator. a fixed shaft installed in the casing so as to pass through the inner part; a combined body rotatably inserted into the fixed shaft by bearings at both ends and consisting of a rotor and a pump blade; each of the bearings and the casing; a thrust bearing interposed between the can, an annular passage formed between the inner circumferential surface of the can and the coupling body, and an axial passage formed outside or inside the fixed shaft. It is.

[Operation] In this invention, a portion of the water discharged from the pump blade passes through the annular passage and the axial passage and circulates back to the pump blade, thereby cooling the inside of the motor.

[Embodiment] An embodiment of the present invention will be described with reference to FIG. FIG. 1 is an axial cross-sectional view, and the same or equivalent parts as those of the conventional device are given the same reference numerals and the explanation thereof will be omitted. In the figure, (11) is the casing, and the casing cover (lla
), pump casing (llb) and motor housing (
lie). (12) is a partition plate installed between the casing cover (11a) and the pump casing (llb), and is a partition plate installed between the water inlet (2a) and the water outlet (2a).
b). (13) is the pump casing (
A cylindrical can integrally molded in the middle part of (14)
) is a bearing portion formed on the free end side of the pump casing (11b), and is supported by the motor housing (lie). (15) is a fixed shaft installed between the bearing part (110) of the casing cover (lla) and the bearing part (14) of the pump casing (llb), and (16) is inserted into the fixed shaft (15). It is a combined body and is rotatably held on a fixed shaft (15) by bearings (17a) and (17b) press-fitted on both ends. This combination (16) is a rotor (7
) and the pump blade (16b) are integrally molded from synthetic resin. (18a), (
18b) is the bearing (17a) and the casing cover (lla
) and between the bearing (17b) and the bearing (14) of the pump casing (llb);
(20) is an annular passage formed between the inner circumferential surface of the fixed shaft (1) and the outer circumferential surface of the body (16a) of the combined body (16);
5) is an axial passage formed in an annular shape between the outer circumferential surface of the coupling body (16) and the inner circumferential surface of the coupling body (16).

Next, the operation will be explained. When the rotor (7) rotates due to the magnetic field generated in the stator (8), this rotational force turns into rotation of the coupling body (16) and is transmitted to the pump blade (16b). At this time, the pressure generated by the rotation of the pump blade (16b) causes water to flow from the water inlet (2a) to the water outlet (2a).
b). Also, a part of the water discharged from the pump vane (16b) enters the annular passage (19) from behind the pump vane (16b), and enters the thrust bearing (18b) and the bearing (17b) from behind the coupling body (16). ) and between the bearing (17b) and the fixed shaft (15) into the axial passage (20), and further between the bearing (17a) and the fixed shaft (15) and the thrust bearing (18a). and bearing (
17a) and is circulated again to the pump vane (16b).

Since the inside of the motor and the bearing section are constantly cooled by a portion of the circulating water in this way, it is possible to suppress a rise in temperature inside the motor. In addition, the thrust bearing (18a),
(18b) is fixed, but each bearing part is constantly lubricated by water.

In the above embodiment, the shaft passes between each bearing (17a), (17b) and each thrust bearing (18a), (18b) and between each thrust bearing (18a), (18b) and fixed shaft (15). Although the one in which water circulates is shown, each bearing (17a
) and (17b) may be formed with water grooves (21) and (22), respectively, to circulate water. For example, Figures 2 and 3
As shown in the figure, axial water grooves (21a) are formed on the inner circumferential surface that slides on the outer circumferential surface of the fixed shaft (15).

(22a) and each thrust bearing (18a), (18b)
Water grooves (21), (2
2) may be formed in each bearing (17a) and (17b), and by doing so, the circulating water can flow through each water groove (21).
) and (22), the flow becomes smooth and the amount of circulating water increases, increasing the cooling effect. At that time, each bearing (17
When a) and (17b) rotate together with the combined body (16), a pumping action is generated by each radial water groove (21b) and (22b), so the combined body (16) is placed on the load side,
It can be balanced against the anti-load side. In addition,
FIG. 3 is an enlarged view of the bearing (17a) in FIG. 2 viewed from the right.

Furthermore, in each of the above embodiments, water is circulated through the axial passage (2o) formed outside the fixed shaft (15), but there is an axial passage (2OA) inside the fixed shaft (15).
may be formed to circulate water. For example, as shown in FIG. 4, the fixed shaft (15) is made hollow and the axial passage (20
A) and the bearing portion (1) of the casing cover (lla) that contacts both ends of the fixed shaft (15)
10) and the bearing part (14) of the pump casing (1l b).
), respectively, by forming water grooves (23a) and (23b) in each groove (23a).
) and (23b), the flow becomes smooth and the amount of circulating water increases, increasing the cooling effect.

Furthermore, if the rotor (7) and the pump blade (16b) are integrally combined as the combined body (16) as in each of the above embodiments, it can be easily manufactured using synthetic resin, and the rotor (7) The pump blade (16b) can be easily attached to the pump blade (16b), and the size can be reduced.

In each of the above embodiments, a horizontal shaft type is shown, but a vertical shaft type may also be used, and although a motor and a pump blade section are shown in a single stage, they may be in multiple stages. Furthermore, although only the improvement in the cooling effect inside the motor has been described, an improvement in the effect of discharging the residual air inside the motor can also be expected.

[Effects of the Invention] As described above, according to the present invention, it is possible to suppress the temperature rise of the entire motor during use, thereby preventing a decrease in operating load.

[Brief explanation of the drawing]

FIG. 1 is an axial sectional view showing one embodiment of the present invention, and FIG.
The figure is an axial sectional view showing a different embodiment of the present invention.
The figure is an enlarged view of the bearing (17a) in Figure 2, viewed from the right.
The figure is an axial sectional view showing still another embodiment of the present invention, and FIG. 5 is an axial sectional view showing a conventional device. In the figure, (7) is the rotor, (8) is the stator (11)
is the casing, (13) is the can, (15) is the fixed shaft,
(16) is the combined body, (16b) is the pump blade, (17a
), (17b) are bearings, (18a), (18b) are thrust bearings, (19) are annular passages, (20), (2OA)
indicates an axial passage. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent: Patent attorney: Masu Oiwa; Kaede Mokuyaku J.

Claims (1)

[Claims] (1) In a device in which a stator is water-sealed by a can located on the inner circumferential surface of the stator within the casing, a fixed shaft installed within the casing so as to penetrate the inside of the stator;
A combined body rotatably inserted into the fixed shaft by bearings at both ends and consisting of a rotor and a pump blade; a thrust bearing interposed between each of the bearings and the casing;
an annular passage formed between the inner circumferential surface of the can and the coupling body, and an axial passage formed outside or inside the fixed shaft, and a part of the water discharged from the pump blade is , an electric pump device characterized in that circulation is returned to the pump blade through the annular passage and the axial passage.