JPH0746727Y2 - Water pump - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water pump for circulating engine cooling water in an engine such as an automobile.

[0002]

2. Description of the Related Art A water pump of this type is disclosed in, for example, Japanese Utility Model Laid-Open No. Sho 63-190594. In this publication, a rotary shaft having an impeller at one end is supported on a pump body via a bearing, a mechanical seal is provided between the bearing and the impeller, and the pump body has a mechanical seal and a bearing. A vapor discharge passage is formed to connect the space chamber between them to the atmosphere. As a result, steam leaking from the mechanical seal portion is discharged to the atmosphere to prevent water from entering the inside of the bearing, thereby preventing the lock phenomenon due to corrosion and grease outflow. In the water pump having the ventilation function as described above, the conventional water pump, for example, the cross-sectional view of FIG. 7 and the line VIII of FIG.
As shown in FIG. 8 of a sectional view taken along line VIII, a cap having a cylindrical shape communicating with the vapor discharge passage 21 is attached to the upper surface of the pump body 28 (for convenience, the same reference numerals are used). A portion 24 is provided, and the attachment portion 24 covers the upper portion of the vapor discharge passage 21 and the discharge passage 21.
There is a cap 1 that is attached to form a discharge path 25 having an opening on the lower surface that communicates with. The cap 1 is a foreign substance to the vapor discharge passage 21, mainly rainwater or muddy water splashed by the traveling of the vehicle (hereinafter collectively referred to as muddy water), or foreign matter such as sand dust, dust (hereinafter collectively referred to as dust). To prevent intrusion. If such foreign matter enters the water pump through the steam discharge passage 21, it will lead to problems such as deterioration of bearing life and defective mechanical seal.

[0003]

In the water pump having the cap 1 as described above, if the gap between the cap mounting portion 24 and the cap 1 at the lower end opening of the discharge passage 25 is too large, It is desirable that the gap be as small as possible because foreign matter is likely to enter the vapor discharge passage 21. However, if the gap is too small, as shown by the chain double-dashed line in FIG. 7, the muddy water covered on the upper surface of the cap 1 is between the lower end portion of the cap 1 and the mounting portion 24, that is, the discharge path 25. There is a possibility that a problem may occur in which the accumulated water is collected near the lower end of the pump, and the accumulated water is pushed up into the discharge passage 25 by the muddy water flowing in the vicinity thereof and then sucked into the pump body through the steam discharge passage 21 due to the siphon phenomenon. is there. For this reason, in the conventional case, there is a limit to reducing the gap, and the effect of preventing foreign matter from entering the pump body remains unsatisfactory.

Therefore, the present invention has been made to solve the above-mentioned problems, and its purpose is to improve the effect of preventing foreign matter from entering the pump body and to improve the life of the bearing and the mechanical seal. It is to provide a water pump that can.

[0005]

In the water pump of the present invention for solving the above problems, a rotary shaft having an impeller at one end is supported by a pump body through a bearing, and a mechanical seal is provided between the bearing and the impeller. In a water pump in which a steam discharge passage is formed in the pump body for communicating the space between the mechanical seal and the bearing with the atmosphere, a cylinder communicating with the steam discharge passage on the upper surface of the pump body. A cap mounting portion having a shape is provided, and a cap that covers the upper portion of the vapor discharge passage and forms a discharge passage having an opening on the lower surface communicating with the discharge passage is attached to the mount portion, and a cap is attached to the lower end portion of the cap. A flange portion is formed to increase the outer diameter.

[0006]

According to the above-mentioned means, since the outer diameter of the cap is increased by the flange portion of the cap, the volume of the space portion formed in the corner portion between the lower portion of the cap and the periphery of the cap mounting portion is increased. To be done. For this reason, the muddy water covered on the upper surface of the cap easily falls downward from the outer end of the flange portion of the cap, and is less likely to collect near the lower end of the discharge path.

[0007]

[Embodiment 1] Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 4 shows a front sectional view of the water pump. In the figure, the casing 11 of the water pump is mainly composed of a pump body 2 and one side of the body 2 (on the right side in the drawing).
And a pump cover 3 which is connected via a gasket 12. The pump body 2 has an opening hole 15 that forms a pump chamber 14 with the pump cover 3, and a bearing mounting hole 17 that communicates with the hole 15 through an intermediate hole 16 and has an outer end opened to the side surface of the body. It is provided on the same axis. The pump chamber 14 is communicated with the engine cooling water for a vehicle as a part of the circulation path.

A rotary shaft 19 is rotatably supported in the bearing mounting hole 17 via a bearing 4. One end portion (the right end portion in the drawing) of the rotary shaft 19 extends to the pump chamber 14, and the impeller 5 is attached to the end portion. The other end of the rotary shaft 19 projects from the side surface of the pump body 2, and the pulley seat 7 is attached to the end by press fitting. A pulley 8 and a fan coupling 10 are joined to the pulley sheet 7 by a stud bolt 9. As is well known, the pulley 8 is provided with a transmission belt (not shown) of a power transmission mechanism for transmitting the driving force of a rotary drive source such as an engine. Therefore, the rotation of the pulley 8 based on the drive of the rotary drive source causes the rotation shaft 19 to rotate, whereby the pump action of the impeller 5 is exerted.

A mechanical seal 6 is provided between the bearing 4 and the impeller 5. Since the mechanical seal 6 is well known, a detailed description thereof will be omitted. However, the mechanical seal 6 includes a fixed side member fixed to the intermediate hole 16 side and a rotary side member fixed to the rotary shaft 19 side. The airtightness of the pump chamber 14 is maintained. Further, the pump body 2 is formed with a steam discharge passage 21 and a drain discharge passage 22 that communicate with a space chamber 20 between the bearing 4 and the mechanical seal 6. Drain discharge passage 22
Is formed in a substantially L-shape so as to face the pulley seat 7 from the bottom of the space chamber 20.

The vapor discharge passage 21 is provided in the space chamber 20.
Vertically extends upward from the uppermost part of the above to open on the upper surface of the pump body 2, and the space chamber 20 thereof is communicated with the atmosphere. The discharge passage 21 serves to ventilate water vapor and the like leaking from the pump chamber 14 to the space chamber 20 due to heat generated on the sliding contact surface between the fixed side member and the rotating side member of the mechanical seal 6 during pump operation.

On the upper surface of the pump body 2, however,
A cylindrical cap attachment portion 24 communicating with the opening of the vapor discharge passage 21 is formed. The cap attachment portion 24 is provided with a cap 1 that covers the vapor discharge passage 21 and prevents foreign matter such as muddy water and dust from entering the discharge passage 21. The mounting portion of the cap 1 is shown in an enlarged scale in FIG.
A line cross section is shown in FIG.

The cap 1 has a bottomed cylindrical shape, and a cross-shaped mounting piece 27 is formed on the bottom surface thereof.
A step portion 28 is formed on the mounting piece 27, and the side surface of the tip end portion is in surface contact with the inner side surface of the cap mounting portion 24 and the step surface is in contact with the end surface of the mounting portion 24. The cap 1 is fitted into the cap mounting portion 24. As a result, a discharge path 25 having an opening on the lower surface is formed between the cap 1 and the cap mounting portion 24 so as to communicate with the vapor discharge path 21. Note that cap 1
As shown in the perspective view of FIG. 3, the U-shaped anti-rotation groove 29 is formed on the side surface of the anti-rotation groove 29. The detent groove 29 engages with a rib 30 formed on the pump body 2 to detent the cap 1 (see FIG. 4).

Further, as shown in FIGS. 1 to 4, at the lower end portion of the cap 1, a collar portion 1a for increasing its outer diameter d is formed. The cap 1 is integrally formed of a synthetic resin material having a low thermal conductivity.

According to the water pump, the cap 1
Since the outer diameter d of the cap 1 is increased by the collar portion 1a of the cap 1, the cap 1 and the cap mounting portion 2
The volume of the space portion (see the alternate long and two short dashes line S in FIG. 1) formed in the corner portion with the periphery of 4 is increased. Therefore, as shown by the arrow in FIG. 1, the muddy water covered on the upper surface of the cap 1 easily falls downward from the outer end of the collar portion 1a of the cap 1, and is unlikely to collect near the lower end of the discharge passage 25. Become.
Therefore, the problem of being sucked into the pump body 2 through the steam discharge passage 21 due to the siphon phenomenon is prevented. As a result, the gap between the cap mounting portion 24 and the cap 1 at the lower end opening of the discharge passage 25 is made small, and the entry of dust into the pump body 2 is prevented, while the entry of muddy water is effectively prevented. It

The clearance area B between the outer peripheral surface of the cap mounting portion 24 and the inner peripheral surface of the cap 1 is defined as
By setting the passage area A to 1 to 2 times, the gap width C between the cap attachment portion 24 and the cap 1 can be set small without increasing the vapor discharge resistance.

Second Embodiment A second embodiment of the present invention will be described. Since this embodiment is a modification of the first embodiment, the same parts are designated by the same reference numerals, and the description thereof will be omitted. Only different configurations will be described in detail. Note that FIG. 5 shows a part of the water pump of this example in a cross-sectional view, and FIG. 6 shows an enlarged view of a main part. In this example, on the lower end surface of the collar portion 1a of the cap 1,
The annular groove 1b is formed, and the wall of the annular groove 1b on the cap attachment portion side is formed lower than the outer wall.

According to this embodiment, the same effect as that of the first embodiment can be obtained. In this case, the volume of the space (see the chain double-dashed line S in FIG. 6) formed in the corner between the lower portion of the cap 1 and the periphery of the cap attachment portion 24 is further increased as compared with the first embodiment. The effect of preventing muddy water intrusion is enhanced.
Further, the wall of the annular groove 1b on the side of the cap mounting portion can prevent splashing of water on the upper surface of the pump body 2 as compared with the case without the wall. The present invention is not limited to the first and second embodiments described above, and modifications can be made without departing from the spirit of the present invention.

[0018]

According to the present invention, the brim portion of the cap enhances the effect of preventing foreign matter from entering the pump body through the steam discharge passage, thereby improving the life of the bearing and the mechanical seal, which in turn increases the life of the water pump. Durability is improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing a first embodiment.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view of a cap.

FIG. 4 is a front sectional view of a water pump.

FIG. 5 is a sectional view showing a part of a water pump according to a second embodiment.

FIG. 6 is an enlarged view of a main part of FIG.

FIG. 7 is a cross-sectional view of an essential part showing a conventional example.

8 is a sectional view taken along line VIII-V1II of FIG.

[Explanation of symbols]

 1 Cap 1a Collar 2 Pump body 21 Steam discharge passage 25 Discharge passage

Claims (1)

[Scope of utility model registration request] 1. A rotary shaft having an impeller at one end thereof is supported by a pump body via a bearing, a mechanical seal is arranged between the bearing and the impeller, and a mechanical seal is provided between the mechanical seal and the bearing on the pump body. In a water pump in which a steam discharge passage that communicates the space chamber with the atmosphere is formed, a cylindrical cap attachment portion that communicates with the vapor discharge passage is provided on the upper surface of the pump body, and the vapor is attached to the attachment portion. A water pump in which a cap that covers an upper part of a discharge passage and forms a discharge passage having an opening on the lower surface that communicates with the discharge passage is attached, and a flange portion that increases the outer diameter is formed at a lower end portion of the cap.