JPH05149288A - Pump for hot water supply device - Google Patents

Abstract

PURPOSE:To dissolve troubles in the opening of a suction port while insuring movement of an impeller in the thrust direction by additionally providing a supporting part to support the center of the impeller capably of being thrusted in the axial direction of a motor on the pump chamber side of a separating plate arranged between the pump chamber and a motor supporting part. CONSTITUTION:An upper case 4 provided with a separating plate 3 and a suction port 4A is fitted on a fitting plate 1 on which a direct current motor 2 is attached. A magnet case 8 receiving a magnet MG is mounted between the fitting plate 1 and the separating plate 3. Further, a pump chamber 9 is formed within the upper case 4. Meanwhile, a magnet MG is arranged in the position opposite to the magnet case 8 in an impeller case 11 to which an impeller 10 is fitted. In this case, a shaft part 3J having its extreme end rounded is projectingly provided on the pump chamber 9 side of the axial part of the separating plate 3. The shaft part 3J is fitted into the recessed part 11U formed in the impeller case 11, and the impeller case is supported with the shaft part 3J rotatably and slidably in the thrust direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater pump.

[0002]

2. Description of the Related Art As a pump for a water heater, Japanese Patent Laid-Open No. 62-
No. 144613, No. 62-261216, No. 62-292114, No. 62-2
There are techniques disclosed in Japanese Patent No. 98687, Japanese Patent Laid-Open No. 63-150036, and the like.

In these disclosed techniques, a separator is provided between the pump chamber and the motor supporting portion, a magnet is attached to an impeller rotatably provided in the pump chamber, and an output shaft side of the motor is provided through the separator. The magnet and the magnet on the impeller side face each other.

Further, an impeller is slidably supported on a fixed shaft provided at the suction port. As a result, the impeller moves in the thrust direction as the pressure inside the pump changes according to the rotational speed of the impeller, the contact point of the bearing changes, and the durability of the bearing portion can be improved.

[0005]

DISCLOSURE OF THE INVENTION In the prior art,
Since the suction port is provided with the obstacle by the fixed shaft, the cross section of the suction port is reduced and the flow rate is limited.

Therefore, an object of the present invention is to provide a pump for a water heater, which secures the movement of the impeller in the thrust direction and has no obstruction at the suction port.

[0007]

In order to achieve the above-mentioned object, the present invention provides a support portion on the pump chamber side of the separator for supporting the impeller center in the axial direction of the motor in a freely thrustable manner.

[0008]

The impeller is supported by the support means provided on the separator side, not the support means provided at the suction port.

[0009]

【Example】

Example 1 (see FIGS. 1 and 4) A DC motor 2 is mounted on a motor mounting plate 1.
The center of the rotation axis of this motor will be referred to as an axis line below. The isolation plate 3 and the upper case 4 are fixed to the mounting plate 1 together with the mounting plate 5 with screws 6. An O-ring 7 for sealing is provided at the joint between the separator 3 and the upper case 4. A suction port 4A is formed in the center of the upper case 4 around the axis.

Between the motor mounting plate 1 and the separator plate 3,
Magnet case 8 that is locked by the motor shaft with a key
Is attached, and the magnet M is
G is stored and heat welded by the iron plate 8A.

The central portion of the magnet case 8 and the facing portion of the separator plate 3 are formed in a conical shape with the axis as the center, and the top portion thereof has a curved surface and rotatably contacts the separator plate 3.

A pump chamber 9 is formed inside the upper case 4 on the side opposite to the motor supporting portion side of the separator 3. The axial portion of the separator 3 projects toward the pump chamber 9 by forming a shaft portion 3J with a rounded tip. The shaft portion 3J is fitted in the concave portion 11U of the impeller case 11 and is rotatable and slidable in the thrust direction.

The impeller 10 is attached to the impeller case 11 by ultrasonic welding with a magnet MG sealed inside at a position facing the magnet case 8.

In this example, the upper case 4 and the impeller 1
0, the impeller case 11, the separator 3, and the magnet case 8 are made of synthetic resin.

According to this construction, since the impeller 10 is supported by the separator 11, the suction port 4A is free from any obstacle and a sufficient flow rate can be obtained. In other words, since the flow rate is high, the inflow velocity of the hot water is reduced, the generation of water vapor in the vortex chamber is eliminated, and it is difficult for idling during boiling to occur. Further, the structure of the upper case 4 is simplified and the number of parts is reduced.

In this example as well, the movable structure of the impeller allows
The discharge amount can be controlled according to the rotation speed of the motor. That is, when the rotational speed is increased and the discharge amount is increased, the pressure in the pump chamber 9 also increases, which causes the impeller 10 to balance the attraction force between the magnet MG in the impeller and the magnet MG on the motor side. It moves in the thrust direction on the suction port side, and when the rotation speed is low, the pressure inside the pump also decreases, and the tip of the shaft portion 3J rotates while coming into contact with the impeller case 11 due to its own weight and the magnet attraction force. Therefore, the sliding contact part during rotation changes depending on the rotation speed of the impeller,
Wear resistance is improved.

Example 2 (see FIG. 2) In this example, instead of the motor mounting plate 1 in the example of FIG. 1, a motor and an upper case 4 are attached to a lower case 12 as shown in FIG. Further, the shaft portion 10J of the impeller 10 is rotatably and thrustably mounted in the recess 3U provided in the separator 3, but other points are the same as those of the example of FIG. Are denoted by the same reference numerals and description thereof will be omitted.

Example 3 (see FIG. 3) In this example, the support structure of the impeller 10 is based on the example of FIG. In addition, the motor 2 is a lower case 12 according to the example of FIG.
Installed on. The different point is the arrangement of the magnets MG, and the magnets MG provided on the outer peripheral portion of the motor shaft are opposed to the magnets MG enclosed in the impeller 10 via the separator 3 in the radial direction. Further, the shaft portion 3J has an impeller 10
It is fitted into the concave portion 10U formed in the above so as to be rotatable and slidable in the thrust direction. Since the other points are the same as those in the example of FIG. 1, the same functional members are designated by the same reference numerals and the description thereof is omitted.

[0019]

As described above, according to the present invention, it is possible to provide a water heater pump which does not have an obstacle at the suction port while ensuring the movement of the impeller in the thrust direction.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a water heater pump according to the present invention.

FIG. 2 is a sectional view of a water heater pump according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view of a water heater pump according to still another embodiment of the present invention.

FIG. 4 is a cross-sectional view when a part of the upper case of FIG. 1 is broken.

[Explanation of symbols]

 3 Separator 3J Shaft 3U Recess 9 Pump Chamber 10 Impeller 10J Shaft 10U Recess 11U Shaft

Claims (1)

[Claims] 1. A separator is provided between a pump chamber and a motor supporting portion, a magnet is attached to an impeller rotatably provided in the pump chamber, and a magnet is provided on the output shaft side of the motor through the separator. In the pump having the magnet on the impeller side opposed to each other, a pump for a water heater is provided on the pump chamber side of the separator, which supports the impeller center so as to freely thrust in the axial direction of the motor.