JPH0547493U - water pump - Google Patents

Abstract

(57) [Summary] [Purpose] Air that collects on the back side of the impeller is smoothly released to the front side of the impeller to reliably prevent air accumulation on the back side of the impeller. [Structure] An L-shaped bent balance hole 10 is formed so as to penetrate between a back surface portion and a front surface portion of the impeller 7.
The opening 10B of the balance hole 10 on the front side of the
The impeller 7 was opened in a direction substantially opposite to the rotating direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a water pump, and more particularly to a water pump suitable for circulating cooling water of an internal combustion engine of an automobile or the like.

[0002]

[Prior Art]

 Conventionally, as this type of water pump, for example, the one described in Japanese Utility Model Laid-Open No. 62-28100 is known.

Such a water pump has a structure in which the back surface of the mechanical seal side of the impeller is brought close to the inner surface of the pump chamber, and the impeller has an axial space between the back surface and the front surface. A balance hole that penetrates straight is formed.

[0004]

[Problems to be solved by the device]

 By the way, in the water pump configured as described above, the gap between the back surface of the impeller and the inner surface of the pump chamber is usually set to a small value of about 1 to 2 mm. Therefore, for example, when pumping water mixed with air such as cooling water for automobile engine, the cooling air is separated from the inner surface of the pump chamber by the centrifugal action. There is a risk that air will accumulate in the space between them and cause air accumulation. When the air pool occurs, the sliding surface of the mechanical seal heats up, the surface is roughened, and the components in the cooling water (antifreezing agent, etc.) are deposited and the mechanical seal is generated. There is a risk that the sealing function of will be damaged and water will leak. Therefore, in such a water pump, it is necessary to let the air escape to the front surface side of the impeller so that the air does not collect on the back surface side of the impeller.

However, although the above-mentioned conventional water pump allows the air on the back surface side of the impeller to escape to the front surface side of the impeller through the balance hole, it has the following problems.

That is, since the balance hole has a simple straight shape, the air in the balance hole is not discharged smoothly at the opening of the balance hole on the front surface side of the impeller, and the dynamic pressure due to the water flow is applied. Air was sometimes pushed back from the balance hole to the back side of the impeller. Moreover, in general, the balance holes are formed in two small places on the impeller with an inner diameter of about 5 to 6 mm, so that the air on the back side of the impeller can be sufficiently released to the front side of the impeller. However, the problem described above, that is, the sealing function of the mechanical seal may be impaired.

An object of the present invention is to provide a water pump capable of smoothly releasing the air collected on the back side of the impeller to the front side of the impeller and reliably preventing the accumulation of air on the back side of the impeller. Especially.

[0008]

[Means for Solving the Problems]

 The water pump of the present invention is a water pump in which a sealing mechanism is provided between the back surface of an impeller located inside the pump chamber of the pump body and the inner surface of the pump body facing the back surface of the impeller. An air vent hole is formed in the impeller, the air vent hole penetrating between the back surface and the front surface of the impeller, and the opening on the front surface side of the impeller opening in a direction substantially opposite to the rotational direction of the impeller. It is characterized by

[0009]

[Action]

 The water pump of the present invention has an air vent hole formed in the impeller, and the opening of the air vent hole on the front surface side of the impeller is opened in a direction substantially opposite to the rotation direction of the impeller. Negative pressure is applied to the air that escapes from the back side of the impeller to the front side through the vent hole, without applying dynamic pressure due to the water flow on the front side of the impeller, and it escapes smoothly.

[0010] Thus, the air pool on the back surface side of the impeller is surely prevented, and the loss of the sealing function such as the mechanical seal due to the air pool is avoided in advance.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. The present embodiment is an application example as a water pump for circulating cooling water of an automobile engine.

In FIG. 1, reference numeral 1 denotes a pump body, which has a structure in which first and second body portions 2 and 3 are connected by bolts (not shown). A pump chamber R, first and second suction ports P ₁ and P ₂ and a discharge port P ₃ are formed in the body 1. A shaft 5 is supported in the hollow portion 2A of the body portion 2 via a bearing 4.

A drive pulley (not shown) is fixed to the left end of the shaft 5 in FIG. 1 via a pulley hub 6, and an impeller 7 located in the pump chamber R is attached to the right end of the shaft 5 in FIG. Is stuck. A mechanical seal 8 located closer to the former and an oil seal 9 located closer to the latter are disposed between the impeller 7 and the bearing 4.

In the impeller 7, two balance holes 10 and 10 penetrating between a rear surface portion (left side surface portion in FIG. 1) and a front surface portion (right side surface portion in FIG. 1) on the mechanical seal 8 side are point-symmetrical. Is formed in. The balance hole 10 has a circular cross section and is bent in an L-shape, and the opening 10A on the back surface side of the impeller faces the mechanical seal 8 side along the axial direction of the impeller, that is, The opening from the right side to the left side in FIG. 3 is opened, while the opening 10B on the front surface side is arranged along the circumferential direction of the impeller 7 in the rotation direction (direction of arrow A in FIG. 2). It opens in the opposite direction.

In the water pump configured as described above, however, the impeller 7 is rotationally driven in the direction of arrow A in FIG. _It is sucked into the pump chamber R from ₁ or P ₂ and then discharged from the discharge port P ₃ . This causes the cooling water to circulate between the engine and the radiator.

The air mixed in the cooling water wraps around to the back surface side of the impeller 7 and is centrifugally separated toward the rotation center of the impeller 7, that is, around the mechanical seal 8 as shown in FIG. Gather in. However, the air passes through the balance hole 10 without being accumulated and is released to the front surface side of the impeller 7. At that time, the hydraulic pressure on the rear surface side of the impeller 7 becomes higher than the hydraulic pressure on the front surface side of the impeller 7, and the air on the rear surface side of the impeller 7 is forced to pass through the balance hole 10. become. However, since the opening 10B of the balance hole 10 on the front surface side of the impeller 7 opens in the direction opposite to the rotation direction of the impeller 7, the air discharged from the opening 10B is not supplied to the pump chamber. Dynamic pressure is not applied by the water flow in R, and conversely, negative pressure is applied, making it easier to escape.

As a result, the air that collects on the back surface side of the impeller 7 is smoothly released to the front surface side of the impeller 7, and there is no air pool, and the mechanical seal 8 caused by the air pool is removed. Loss of the sealing function will be avoided in advance.

It should be noted that the number of balance holes 10 formed and the cross-sectional shape thereof are arbitrary, and the point is that the opening 10 B on the front surface side of the impeller 7 opens in a direction substantially opposite to the rotation direction of the impeller 7. It should be. Further, in the above embodiment, the balance hole 10 has both the balance function for balancing the rotation of the impeller and the air bleeding function, but these functions may be performed by separate holes. It suffices that at least the latter hole having the same function as the air bleeding is the same as the balance hole 10 of the above-mentioned embodiment.

[0019]

[Effect of the device]

 As described above, in the water pump of the present invention, the air vent hole is formed in the impeller, and the opening of the air vent hole on the front surface side of the impeller is opened in a direction substantially opposite to the rotation direction of the impeller. Because of its structure, negative pressure is applied to the air that escapes from the back side of the impeller to the front side through the air vent hole, without applying a dynamic pressure due to the water flow on the front side of the impeller, and smoothly. Can be escaped.

As a result, it is possible to reliably prevent air accumulation on the back surface side of the impeller and prevent loss of the sealing function such as a mechanical seal due to the air accumulation.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view of the impeller shown in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

4 is an enlarged cross-sectional view of a portion around a balance hole of the impeller shown in FIG.

[Explanation of symbols]

 1 Pump body 2, 3 Body part 4 Bearing 5 Shaft 6 Pulley hub 7 Impeller 8 Mechanical seal 9 Oil seal 10 Balance hole 10A, 10B opening R Pump chamber

Claims (2)

[Scope of utility model registration request] 1. A water pump in which a sealing mechanism is provided between a back surface of an impeller located in a pump chamber of a pump body and an inner surface of the pump body facing the back surface of the impeller, wherein the impeller is provided. And an air vent hole that penetrates between the back surface portion and the front surface portion of the impeller and has an opening on the front surface side of the impeller that opens in a direction substantially opposite to the rotational direction of the impeller. Water pump to do. 2. The water pump according to claim 1, wherein the air vent hole is a balance hole for balancing the rotation of the impeller.