JP2006274886A - Water pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water pump surely storing a fixed amount of leaked water in a reservoir part, and preventing the leaked water from leaking out of the reservoir part unless the leaked water exceeds a certain amount. <P>SOLUTION: The water pump comprises: an impeller 17 disposed to one end of a rotational shaft 14 which is supported by a body 11 through a bearing 13; a mechanical seal 18 disposed between the impeller and the bearing; a drain discharge hole 22 guiding water drops, which has leaked from an impeller side through the mechanical seal, to the reservoir part 22a which is disposed to a lower part of the body; and a drainage hole 24 formed in an upper part of the reservoir part to make the reservoir part communicate with the atmosphere. A step 22c projected all around in a radial direction is formed between the drainage hole and an opening face 22b opening to the reservoir part 22a of the drain discharge hole 22 so that the drainage hole is positioned above the opening face. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a water pump used in a water-cooled engine.

  Conventionally, a water pump used in a water-cooled engine has an impeller provided at one end of a rotating shaft supported on a body via a bearing, and rotates the rotating shaft to circulate cooling water through the engine (for example, Patent Documents). 1-3). In this water pump, since a part of the water droplets that have entered the vapor shape through the mechanical seal is condensed in the space formed between the bearing and the mechanical seal provided between the impeller and the bearing, the condensed water droplet ( Water leakage) is discharged to a reservoir provided at the lower part of the body through the drain discharge hole.

  The reservoir is formed by closing the opening of a recess formed in the lower part of the body with a plug, and a drain hole is provided above the plug to communicate the reservoir with the atmosphere. Therefore, in this water pump, condensed water droplets do not directly flow out of the drain discharge hole but are stored in the reservoir within a certain range.

In particular, in the water pump of Patent Document 1, it has been proposed to form a groove in the reservoir that guides water droplets flowing out from the drain discharge hole to the lower portion of the reservoir, so that the water droplet (leakage) is reliably accumulated in the reservoir. Yes.
JP 11-336699 A JP 2004-108250 A Registered Utility Model No. 02055777

  By the way, in the water pump of Patent Document 1, the opening surface of the drain discharge hole in the reservoir (the inner wall surface of the reservoir where the drain discharge hole is open) and the inner wall surface of the drain hole are directly connected. These drain discharge holes and drain holes are often adjacent to each other. Accordingly, there is a possibility that water droplets flowing out (leaking) from the drain discharge hole may be transmitted to the atmosphere side (outside) through the inner wall surface of the drain hole due to surface tension.

  On the other hand, in the water pump of Patent Document 2, although the stepped portion is provided in a part of the opening surface so that the drain hole is located above the opening surface of the drain discharging hole, the opening surface of the drain discharging hole is still provided. Since it is directly connected to the inner wall surface of the drain hole, water droplets that have flowed out (leaked) from the drain discharge hole may flow out to the atmosphere side (outside).

  An object of the present invention is to provide a water pump that reliably accumulates a certain amount of water leakage in a reservoir and does not flow outside unless the water leakage exceeds a certain amount.

  In order to solve the above-mentioned problems, an invention according to claim 1 includes an impeller provided at one end of a rotating shaft supported by a body via a bearing, and a mechanical seal provided between the impeller and the bearing. And a drain discharge hole for leading water droplets leaking from the impeller side through the mechanical seal to a reservoir provided below the body, and provided at the upper portion of the reservoir, and the reservoir communicates with the atmosphere. In a water pump provided with a drain hole, the drain hole is located between the drain hole and an opening surface where the drain discharge hole opens in the reservoir, so that the drain hole is located above the opening surface. The gist is that a stepped portion projecting radially is provided over the circumference.

The invention according to claim 2 is characterized in that, in the water pump according to claim 1, the stepped portion is inclined so as to form an acute angle toward the drain hole.
According to a third aspect of the present invention, in the water pump according to the first or second aspect, the reservoir has an opening that is widened through the stepped portion of a recess formed in a lower portion of the body. It is formed by closing with a plug, and the gist is that the drain hole is arranged on the plug side with respect to the stepped portion.

(Function)
According to the first aspect of the present invention, the entire periphery of the drain hole is located above the opening surface between the drain hole and the opening surface where the drain discharge hole opens in the reservoir. By providing the step portion protruding in the radial direction, the opening surface and the inner wall surface of the drain hole are not directly connected. Therefore, it is possible to prevent water droplets leaking from the drain discharge hole from flowing out to the atmosphere side (outside) through the inner wall surface of the drain hole, and to reliably collect water leakage in the reservoir. Further, since the stepped portion protrudes in the radial direction over the entire circumference, the function of the stepped portion itself is not affected by the mounting angle of the water pump around its axis (the axis of the reservoir), and the water The degree of freedom of the mounting angle of the pump can be increased.

  According to the second aspect of the present invention, the step portion is inclined so as to form an acute angle toward the drain hole, so that water droplets that have leaked from the drain discharge hole are transmitted to the step portion. Even so, a certain amount of water is accumulated by surface tension at the corner of the drain hole formed so as to form an acute angle by this inclination, and is transmitted to the atmosphere side through the inner wall surface of the drain hole. (Outside) can be more reliably prevented from flowing out.

  According to invention of Claim 3, the said drain hole is arrange | positioned in the said plug side rather than the said level | step-difference part, and the said drain hole and the said opening surface are separated by the part. In particular, the water drainage hole is provided in the upper portion of the reservoir portion on the plug side of the stepped portion, so that two steps are set between the opening surface and the water drainage hole. As described above, it is possible to more reliably prevent water droplets leaking from the drain discharge hole from flowing out to the atmosphere side (outside) through the inner wall surface of the drain hole.

  As described above in detail, the invention according to any one of claims 1 to 3 can provide a water pump that reliably accumulates a certain amount of water leakage in the reservoir and does not flow outside unless the leakage exceeds a certain amount. it can.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, the body 11 is fixed to a cylinder block 12 by a fixing member (for example, a bolt or the like), and a rotating shaft 14 is supported on the body 11 via a bearing 13. A driving pulley 15 is fixed to one end of the rotating shaft 14 by a fixing member such as a bolt through a pulley bracket 16, and an impeller 17 is fixed to the other end by press-fitting. The impeller 17 is rotated by the rotation of the rotating shaft 14. To do. An annular mechanical seal 18 is disposed between the impeller 17 and the bearing 13, and a space 19 is formed between the mechanical seal 18 and the bearing 13. A slight gap 20 between the mechanical seal 18 and the rotary shaft 14 exists in the space 19, and water droplets (leakage) in the form of vapor enter the gap 19 from the impeller side through which the cooling water flows.

  The body 11 is formed with a vapor discharge hole 21 through which a vapor-like one of the water droplets escapes obliquely upward, and a drain discharge hole 22 through which condensed water droplets are discharged obliquely downward. The drain discharge hole 22 extends obliquely downward from the space 19 and communicates with a reservoir 22 a provided below the body 11. The reservoir 22a is formed of a recess 22d formed in a substantially circular cross section so that a center line extends in parallel with the rotary shaft 14 from a side opposite to the impeller 17 (on the drive pulley 15 side) at the lower portion of the body 11. The opening formed in the drive pulley 15 is closed by a plug 23. Further, the body 11 is formed with a drain hole 24 provided in the upper part of the plug 23 so as to be recessed above the upper end of the plug 23 and communicating with the reservoir 22a and the atmosphere. The extending direction of the drain discharge hole 22 is shifted in the circumferential direction with respect to the drain hole 24 (see FIG. 2B).

  As shown in FIGS. 2 (a) and 2 (b), the drain hole 24 and the opening 22b where the drain discharge hole 22 opens into the reservoir 22a (of the reservoir 22a where the drain discharge hole 22 is open). A stepped portion 22c protruding in the radial direction over the entire circumference is provided so that the drain hole 24 is above the opening surface 22b. That is, the reservoir 22a has a small diameter portion and a large diameter portion in such a manner that the opening closed by the plug 23 is expanded through the step portion 22c. The drain discharge hole 22 opens to the small diameter portion, and the drainage hole 24 is disposed further above the expanded opening (plug 23).

  Accordingly, the opening surface 22b and the inner wall surface of the drain hole 24 are not directly connected to each other, and the stepped portion 22c has a water drop leaking from the drain discharge hole 22 transmitted along the inner wall surface of the drain hole 24 (at the atmosphere side) It is possible to prevent the water from flowing out to the outside), and water droplets can be dropped into the reservoir 22a.

  Further, the step portion 22c is inclined so as to form an acute angle with the drain hole 24 side (plug 23 side) to form an annular inclined surface. That is, the step portion 22c is formed such that an angle θ formed in a cross section with an opening portion (large diameter portion) closed by the plug 23 of the reservoir portion 22a is an acute angle. Therefore, even if water droplets leaking from the drain discharge hole 22 are transmitted through the stepped portion 22c, a certain amount of water is accumulated at the corner portion on the side of the drainage hole 24 that forms an acute angle. It can be more reliably prevented from flowing to the atmosphere side (outside) through the wall surface.

  Next, the operation of the water pump will be described. In this water pump, the rotating shaft 14 is integrally driven by the rotation of the belt 25 applied to the driving pulley 15 as the external driving source rotates. When the rotating shaft 14 is driven, the impeller 17 that rotates integrally with the rotating shaft 14 rotates, and the cooling water supplied to each part of the engine is sucked from the cooling water inlet 26 formed in the cylinder block 12 to be cooled. It is discharged from the outlet 27 and supplied to the engine.

  At this time, vapor-like water droplets enter the space 19 through a gap 20 formed between the mechanical seal 18 and the rotary shaft 14, and the vapor-like water droplets are discharged from the vapor discharge hole 21. The water droplets condensed from the vapor form are guided to the reservoir 22a from the lower drain discharge hole 22, and in the reservoir 22a, a certain amount until the water level at which the drain hole 24 is formed (allowance of the reservoir 22a). Capacity) is stored in the reservoir 22a. In this case, the water droplets are transmitted through the opening surface 22b due to the surface tension and try to flow out to the atmosphere side. However, by providing the stepped portion 22c, the water droplets leaking from the drain discharge hole 22 are discharged from the drain hole 24. It can be prevented from flowing out to the atmosphere side through the inner wall surface, and water droplets can be dripped into the reservoir 22a.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) In the present embodiment, the drainage hole 24 is located above the opening surface 22b between the drainage hole 24 and the opening surface 22b where the drain discharge hole 22 opens in the reservoir 22a. By providing the step portion 22c projecting in the radial direction over the entire circumference, the opening surface 22b and the inner wall surface of the drain hole 24 are not directly connected. Accordingly, it is possible to prevent water droplets leaking from the drain discharge hole 22 from flowing out to the atmosphere side (outside) through the inner wall surface of the drain hole 24, and to reliably collect water leakage in the reservoir 22a. it can. Further, since the stepped portion 22c protrudes in the radial direction over the entire circumference, the function of the stepped portion 22c itself is not affected by the mounting angle of the water pump around its axis (the axis of the reservoir 22a). The degree of freedom of the mounting angle of the water pump can be increased.

  (2) In the present embodiment, the stepped portion 22c is inclined so as to form an acute angle toward the drain hole 24 side. Therefore, even if water droplets leaking from the drain discharge hole 22 are transmitted to the stepped portion 22c, a certain amount of water is generated at the corner portion on the drainage hole 24 side formed to form an acute angle by this inclination. Therefore, it is possible to more reliably prevent the water from flowing out to the atmosphere side (outside) through the inner wall surface of the drain hole 24.

  (3) In the present embodiment, the drain hole 24 is disposed closer to the plug 23 than the stepped portion 22c, so that the drain hole 24 and the opening surface 22b are separated by that amount. The In particular, the drainage hole 24 is provided at the upper portion of the reservoir 22a on the plug 23 side of the stepped portion 22c, so that two steps are set between the opening surface 22b and the drainage hole 24. Will be. As described above, it is possible to more reliably prevent water droplets leaking from the drain discharge hole 22 from flowing out to the atmosphere side (outside) through the inner wall surface of the drain hole 24.

(4) In this embodiment, since the inner wall surface (recess 22d) of the reservoir 22a can be formed only by casting in the center line direction, an increase in cost can be suppressed.
In addition, you may change the said embodiment as follows.

  In the embodiment, the step portion 22c may be inclined so as to form an obtuse angle on the drain hole 24 side. Further, the stepped portion 22c may be formed so as to make a right angle to the drain hole 24 side.

-In the said embodiment, you may extend the drain hole 24 to a longitudinal direction (centerline direction of the reservoir 22a) to the deepest part (bottom surface of the recessed part 22d) of the reservoir 22a.
In the embodiment, the recess 22d of the reservoir 22a may be formed by drilling or cutting.

  In the above embodiment, if the drain discharge hole 22 and the drain hole 24 do not interfere (intersect), the extending direction of the drain discharge hole 22 is not shifted in the circumferential direction with respect to the drain hole 24. You may arrange.

Sectional drawing which shows one Embodiment of this invention. (A) is an enlarged view which shows the range A of FIG. 1, (b) is the cross-sectional view.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Body, 13 ... Bearing, 14 ... Rotary shaft, 17 ... Impeller, 18 ... Mechanical seal, 22 ... Drain discharge hole, 22a ... Reservoir, 22b ... Opening surface, 22c ... Step part, 22d ... Recess, 23 ... Plug , 24 ... drain holes.

Claims (3)

An impeller provided at one end of a rotating shaft supported by a body via a bearing;
A mechanical seal provided between the impeller and the bearing;
A drain discharge hole for guiding water droplets leaked from the impeller side through the mechanical seal to a reservoir provided below the body;
In the water pump provided at the upper part of the reservoir, and having a drain hole for communicating the reservoir with the atmosphere,
Between the drain hole and the opening surface where the drain discharge hole opens to the reservoir, a stepped portion protruding radially is provided over the entire circumference so that the drain hole is above the opening surface. A water pump characterized by The water pump according to claim 1,
The water pump according to claim 1, wherein the step portion is inclined so as to form an acute angle toward the drain hole. In the water pump according to claim 1 or 2,
The reservoir is formed by closing an opening that is widened through the stepped portion of a recess formed in a lower portion of the body with a plug,
The water pump according to claim 1, wherein the drain hole is disposed closer to the plug than the stepped portion.

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