JPS6237135Y2 - - Google Patents

Description

[Detailed description of the invention] This invention applies tap water flowing from a direction parallel to the impeller axis through a rectifier to the impeller, causes the impeller to rotate according to the flow rate of the tap water, and This invention relates to an axial flow impeller type water meter that measures the flow rate of tap water passing through.

Conventionally, this type of axial flow impeller type water meter has had a configuration as shown in FIG. 1, for example. In the figure, the reference numeral 1 indicates an inner case, and the reference numeral 2 indicates a rectifier. Inner case 1 is rectifier 2
and is supported within the main case 3. The inner case 1 has a cylindrical portion 1a, and an impeller chamber 4 is formed within the cylindrical portion 1a. The blade portion 6 of the impeller 5 is housed in the impeller chamber 4. The blade portion 6 includes a cylindrical central boss portion 6a and its boss portion 6.
It consists of a plurality of blades 6b extending radially from a at a constant twist angle, and an impeller shaft 7 is inserted through the boss portion 6a. This impeller shaft 7 is arranged along the center of the cylindrical portion 1a, and is supported between a rod-shaped upper bearing 8 and a pivot shaft 9, thereby making the impeller 5 rotatable. The pivot shaft 9 is screwed into the boss portion 2a of the rectifier 2, and is fixed to the rectifier 2 by tightening a nut 10 that is threaded onto the projecting end of the pivot shaft 9. In the conventional axial impeller type water meter, the boss diameter D of the boss portion 6a of the impeller 5 is made smaller than the boss diameter d of the boss portion 2a of the rectifier 2. Tap water flowing in from a direction parallel to the impeller shaft 7 hits the blades 6b of the impeller 5, causing the impeller 5 to rotate in accordance with the flow rate of the tap water. That is, tap water enters the rectifier 2 from the direction of arrow A in the figure, is rectified by the rectifier 2, hits the blades 6b, rotates the impeller 5, and is then discharged from the outlet passage 1b. At this time, the rotation of the impeller 5 is transmitted upward by the impeller shaft 7, and the flow rate of the tap water passing through is displayed on the upper display section.

In the conventional axial impeller type water meter of this type, the impeller 5 was thought to float due to the lifting force of tap water flowing in from a direction parallel to the impeller axis 7. However, in reality, depending on the type of device, the impeller 5 does not float up, and the pivot shaft 9
Trouble often occurred due to wear of the tip.

Therefore, the purpose of this invention is to prevent the above-mentioned trouble from occurring in such an axial flow impeller type water meter.

In order to achieve this purpose, the inventors of the axial flow impeller type water meter set the ratio k between the boss diameter D of the impeller 5 and the boss diameter d of the rectifier 2, leaving other conditions unchanged. The thrust load applied to the upper bearing 8 or the pivot shaft 9 was plotted for each flow rate when tap water was flowing, and the experimental results shown in FIGS. 5 and 6 were obtained. In FIGS. 5 and 6, curve A is curve A when k is ka much larger than 1, curve B is curve C when k is smaller than ka but k _b which is still much larger than 1, and curve C is ka when k is much larger than 1. When k is smaller than 1, as in the conventional axial flow impeller type water meter shown in Figure 1, and curve _D shows the case when k is smaller than k _b and slightly larger than 1, k _d . show.

As can be seen from Figures 5 and 6, in the conventional axial flow impeller type water meter as shown in Figure 1,
As shown by curve C, as the flow rate of tap water increases, the thrust load applied to the pivot shaft 9 becomes extremely large, causing the tip of the pivot shaft 9 to wear out. However, in contrast to the conventional water meter shown in FIG. 1, if the boss diameter D of the impeller 5 is made much larger than the boss diameter d of the rectifier 2, the tap water As the flow rate increases, the impeller 5 rises, and the thrust load received by the upper bearing 8 becomes extremely large, causing the tip of the upper bearing 8 to wear out. Therefore, if the boss diameter D of the impeller 5 is made slightly larger than the boss diameter d of the rectifier 2, as shown by the curve D, as the flow rate of tap water increases, the thrust load received by the upper bearing 8 increases; The influence of other k
Rather than the _{ratio of a.k.b.k.c. , favorable} results can be obtained that can achieve the purpose of the present invention.

Therefore, in the above-mentioned axial flow impeller type water meter, the present invention is to make the diameter of the impeller boss part at least on the rectifier side larger than that of the rectifier boss part so that the impeller floats within a predetermined flow rate range. It is characterized by

Hereinafter, the present invention will be specifically explained based on the embodiment of the present invention shown in FIG. FIG. 2 is a longitudinal sectional view of the axial impeller type water meter with the main case removed. In Fig. 2, the boss diameter of the impeller 15 is
By making D ₁ slightly larger than the boss diameter d ₁ of the rectifier 12, the amount of floating of the impeller 15 can be adjusted and the thrust load applied to the pivot shaft 19 can be reduced or eliminated. In the figure, the impeller 15 is composed of a blade part 16 and an impeller shaft 17, and the blade part 16 has an impeller shaft 17 in the center, similar to the conventional axial flow impeller type water meter shown in FIG.
It consists of a cylindrical central boss part 16a that penetrates through the center boss part 16a, and a plurality of blades 16b that extend radially from the boss part 16a at a constant twist angle. However, boss part 1
6a is different from the boss portion _{6a of} the conventional axial impeller type water meter shown in FIG. Boss portion 16a of impeller 15 and rectifier 1
A vane portion 16 is located above the rectifier 12 and is located on the same straight line as the boss portion 12a of No. 2.

Further, FIG. 3 shows a disk 41 attached to the axial impeller type water meter shown in FIG. 2. Here, the same components as shown in the axial flow impeller type water meter shown in FIG. 2 are given the same reference numerals, and the explanation thereof will be omitted. In Fig. 3, impeller 2
5 is made larger than _{the boss diameter d 2 of} the rectifier 22, a disk 41 is arranged between both bosses, and the amount of lift of the impeller 25 is adjusted by changing the outer diameter of the disk 41. However, the thrust load applied to the pivot shaft 19 can be reduced or eliminated. In the figure, a disk 41 is provided above the boss portion 22a of the rectifier 22, and the pivot shaft 19 passing through the center of the disk 41 is screwed into the boss portion 22a.
The nut 30 is inserted with its tip protruding from the boss portion 22a.
Fix it with. The impeller 25 is supported between the upper bearing 18 and the pivot shaft 19, and the blade portion 26 is supported between the upper bearing 18 and the pivot shaft 19.
Provided above 1. The outer diameter of the disk 41 is the impeller 25
is smaller than the boss diameter D ₂ of the rectifier ₂₂ .
bigger. This disk 41 can be easily attached to and removed from the rectifier 22, and by appropriately changing the outer diameter of the disk 41, the amount of floating of the impeller 25 can be adjusted.

Furthermore, FIG. 4 is a longitudinal cross-sectional view of an axial impeller type water meter showing another embodiment of the present invention, with the main case removed. In FIG. 4, the boss portion 36a of the impeller 35 is formed into a conical shape, and the diameter of the bottom surface thereof is
By making D ₃ larger than the boss diameter d ₃ of the rectifier 32, the impeller 35 can be lifted up, and the thrust load applied to the pivot shaft 39 can be reduced or eliminated. In the figure, the impeller 35 is composed of a blade part 36 and an impeller shaft 37.
6 consists of a conical boss portion 36a through which the impeller shaft 37 is inserted through the center, and a plurality of blades 36b extending radially from the boss portion 36a at a constant twist angle. The impeller 35 is provided so that the bottom surface of its boss portion 36a is above the boss portion 32a of the rectifier 32, and the diameter _D3 of the bottom surface of the impeller 35 is made slightly larger than the boss diameter _d3 of the rectifier 32.

As mentioned above, by making the diameter of the impeller boss slightly larger than the diameter of the rectifier boss, the amount of floating of the impeller due to flowing water is adjusted within the appropriate flow rate range, and the distance between the upper bearing and the pivot shaft is adjusted. This has the advantage that it floats in a well-balanced manner, reducing or eliminating the thrust load applied to the pivot shaft, and eliminating troubles caused by wear at the tip of the pivot shaft.

[Brief explanation of the drawing]

Fig. 1 is a partial vertical sectional view of a conventional axial impeller water meter, Fig. 2 is a longitudinal sectional view of an axial impeller water meter showing an embodiment of the present invention, excluding the main case, and Fig. 3. is a vertical sectional view of the axial impeller type water meter shown in Fig. 2 with a disk attached, and Fig. 4 is a vertical sectional view of the axial impeller type water meter excluding the main case showing another embodiment of the present invention. , FIG. 5 is an experimental thrust load curve of the upper bearing with respect to flow rate, and FIG. 6 is an experimental thrust load curve of the pivot shaft with respect to flow rate. 12/22/32... Rectifier, 12a/22
a, 32a...boss part, 15, 25, 35...impeller, 16a, 26a, 36a...boss part, d ₁ .
d ₂・d ₃ ...boss diameter, which is the diameter of the boss part of the rectifier,
D ₁・D ₂ ...Boss diameter, which is the diameter of the boss part of the impeller,
D ₃ ...The diameter of the bottom of the boss, which is the diameter of the impeller boss.

Claims (1)

[Scope of utility model registration request] The rectifier comprises a rectifier, a pivot shaft supported vertically at a central boss portion of the rectifier, and an impeller rotatably supported on the pivot axis with the rectifier and the boss portions of each other arranged in a straight line. A vertical axial flow impeller type in which tap water flowing in parallel to the impeller axis of the impeller hits the impeller and rotates the impeller, and the flow rate of tap water passing through is measured from the rotation. In the water meter, an axial impeller type water supply system, characterized in that the diameter of at least the rectifier side of the boss part of the impeller is made larger than the boss part of the rectifier so that the impeller floats in a predetermined flow rate range. meter.