JP2013036425A - Water pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water pump in which it is possible to suppress disadvantage that a bearing is affected by cooling water having intruded inside a pump housing after crossing a mechanical seal.SOLUTION: In the water pump 1 in which a side wall part 4e opposed to a bearing 6 at a tubular base part 4a of a pulley 4 is provided with a discharge hole 17 connecting the inside with the outside of the pump housing 2 and the discharge hole 17 is covered with a cover member 5, an elastic contact part 5c of the cover member 5 is brought into elastic contact with a second side wall part 4f of a pulley 4 to hold the both in a mutually close contact state, so that an air flow through the discharge hole 17 can be blocked. Thereby, cooling water intruded into the pump housing 2 after passing through the mechanical seal 10 is prevented from reaching to the bearing 6 side, and can be discharged to the outside through a communication hole 15 formed to penetrate in the radial direction (vertical direction) of the pump housing 2.

Description

  The present invention relates to a water pump that is applied to, for example, an engine cooling device of an automobile and is provided for circulation of cooling water in the cooling device.

  As a conventional water pump, for example, one described in Patent Document 1 below is known.

  That is, the water pump has a substantially cylindrical pump housing whose one end is attached and fixed to a side end of the engine block, and a pulley that is rotatably supported on the outer periphery of the other end of the pump housing via a bearing. And a rotary shaft extending in the axial direction so as to pass through the inner periphery of the pump housing from the central portion of the pulley, and a power transmission member fixed to the tip of the rotary shaft. An impeller to be accommodated, and a mechanical seal interposed between the inner peripheral surface of the pump housing on the outer peripheral side of the intermediate portion of the drive shaft and blocking the cooling water flowing into the pump housing from the impeller side. .

  Here, in the water pump, the mechanical seal prevents the intrusion of cooling water from the impeller side. However, the mechanical seal cannot completely block the intrusion of the cooling water. By providing a plurality of through holes in the opposite pulley side walls, the cooling water that has entered the pump housing beyond the mechanical seal can be discharged to the outside through the respective through holes. It is intended to suppress the problem that the cooling water that has entered the pump housing reaches the bearing.

  Japanese Patent No. 4547976

  However, since the conventional water pump is configured to discharge the cooling water (water vapor) that has penetrated beyond the mechanical seal through each through-hole, the through-hole is aligned along the axial direction. An air flow (air flow) is formed.

  Then, since each said through-hole is adjacently arranged in the bearing vicinity, the said cooling water will act on a bearing at the time of discharge | emission of the said cooling water, As a result, the durability of the said bearing will be reduced. There was a fear.

  The present invention has been devised in view of the actual situation of the conventional water pump, and is provided with a through hole in the side wall of the pulley facing the bearing, but from the impeller side over the mechanical seal into the pump housing. It is an object of the present invention to provide a water pump that can suppress the inconvenience that the intruding cooling water reaches the bearing due to the airflow generated through the through hole.

  The present invention provides a water pump in which a through hole communicating with the inside and outside of the pump housing is provided on the side wall of a pulley facing a bearing disposed on the outer periphery of the cylindrical base, and the through hole is covered with a cover member. It is characterized in that the outer peripheral area of the through hole in the pulley and the cover member are held in close contact with each other to prevent communication with the outside of the through hole.

  In addition, it is desirable to inhibit the communication with the outside of the through hole by directly closing the through hole.

  According to the present invention, since the communication with the outside of the through hole is inhibited, not only the cooling water (water vapor) is discharged through the through hole but also the airflow generated through the through hole can be suppressed. As a result, even when the cooling water enters the pump housing from the impeller side beyond the mechanical seal, the cooling water is discharged to the outside through the water vapor discharge hole without moving to the through hole side. It becomes. As a result, the disadvantage that the cooling water acts on the bearing is suppressed, and the durability of the bearing can be improved.

  In addition, when the communication with the outside of the through hole is obstructed by directly closing the through hole, the air flow through the through hole can be blocked more effectively, and thus the above inconvenience is more effective. Can be suppressed.

It is a disassembled perspective view of the water pump which concerns on this invention. It is a front view of the water pump shown in FIG. It is the sectional view on the AA line of FIG. It is the figure which looked at the hole for discharge shown in FIG. 3 from the front. It is a principal part enlarged view of FIG. It is sectional drawing equivalent to FIG. 3 which shows 2nd Embodiment of the water pump which concerns on this invention.

  Hereinafter, each embodiment of the water pump according to the present invention will be described with reference to the drawings. In each of the following embodiments, the water pump according to the present invention is applied to an automotive engine cooling device similar to the conventional one, and the water pump is disposed on the side of the engine block, and the engine crankshaft. The cooling water is circulated in the engine block using the rotational driving force of the engine as a power source.

  FIG. 1 is an exploded perspective view of a water pump according to the present invention, and FIG. 2 is a view of the water pump shown in FIG. 1 as viewed from the side facing the engine block.

  That is, the water pump 1 has a cylindrical portion 11 formed in a stepped diameter shape at one end in the axial direction thereof, and is fixed to the side of the engine block outside the figure via a flange portion 2a at the other end. Thus, a substantially cylindrical pump housing 2 defining a pump chamber P which is a so-called volute chamber with the engine block, and a drive shaft inserted and arranged along the axial direction on the inner peripheral side of the pump housing 2 3 and a pulley 4 fixed to the outer periphery of one end of the drive shaft 3 facing from the one end side of the pump housing 2 to transmit the rotational driving force of the crankshaft to the drive shaft 3 via a belt (not shown), A cover member 5 that is fixedly disposed at the outer end of the pulley 4 and covers substantially the entire outer surface of the pulley 4 is interposed between one end of the pump housing 2 and the pulley 4, and rotates the pulley 4. A bearing 6 that is freely supported, a shielding plate 7 that is arranged adjacent to the inner surface of the bearing 6 that is exposed to the outside, and shields foreign matter such as rainwater from entering the bearing 6, and a pump housing And an impeller 8 that is fixed to the outer periphery of the other end of the drive shaft 3 facing the pump chamber P from the other end side of the shaft 2 and is housed and disposed rotatably in the pump chamber P.

  FIG. 3 is a longitudinal sectional view taken along the line AA in FIG. 2, and shows details of the configuration of the water pump 1. FIG. 4 is an enlarged arrow view of the discharge hole 14 described later shown in FIG. 3 as viewed from the pulley 4 side, and is a diagram showing details of the configuration of the discharge hole 14. Further, FIG. 5 is an enlarged view of a main part of the communication inhibition means described later shown in FIG. 3 and is a diagram showing details of the configuration of the communication inhibition means.

  As shown in FIG. 3, the pump housing 2 is integrally formed by aluminum die casting, and the cylindrical portion 11 includes a large diameter portion 11a adjacent to the flange portion 2a and the large diameter portion 11a. And is connected to the intermediate diameter portion 11b via a step portion 11d, and has an inner diameter toward the distal end side of the cylindrical portion 11. A small-diameter portion 11c configured to be gradually reduced, and the lower end of the middle-diameter portion 11b is defined by being sealed by a stopper member 9 through a drain hole 13 described later. A drain chamber 12 communicating with the inside of the medium diameter portion 11b is provided.

  A known mechanical seal 10 is interposed in the middle diameter portion 11b between the inner peripheral surface of the end portion on the large diameter portion 11a side and the outer peripheral surface of the drive shaft 3 opposite to the inner peripheral surface. Thus, intrusion of cooling water (water vapor) from the pump chamber P side is suppressed. However, since this mechanical seal 10 alone cannot completely prevent the intrusion of cooling water from the pump chamber P side, the internal space of the medium diameter part 11b is located at the position that is the lowest vertical position on the peripheral wall of the medium diameter part 11b. A drain hole 13 that communicates S with the drain chamber 12 is formed so as to penetrate along the Y-axis direction in FIG. 3, and cannot be suppressed by the mechanical seal 10 by the drain hole 13 into the medium diameter portion 11 b. The cooling water that has flowed in is guided to the drain chamber 12 so that the cooling water does not flow out toward the small diameter portion 11c.

  As shown in FIG. 4, a drain hole 14 communicating with the outside and the drain chamber 12 is formed through the side of the drain chamber 12 on the pulley 4 side. The cooling water stored in the drain chamber 12 can be discharged to the outside. Thereby, the disadvantage that the cooling water saturated in the drain chamber 12 returns to the internal space S of the medium diameter portion 11b and flows out to the small diameter portion 11c side is suppressed. The discharge hole 14 is provided so as to be in direct communication with only the drain chamber 12 in a state of being biased with respect to the drain hole 13, and only the vertically lower portion thereof opens to the side portion of the drain chamber 12. Is provided. With this configuration, the discharge hole 14 is provided only for directly discharging the cooling water saturated in the drain chamber 12 from the drain chamber 12, and the air flow generated through the discharge hole 14 is generated by the drain hole 13. The movement of the cooling water (water vapor) rising to the communication hole 15 side is not hindered.

  Further, a communication hole 15 (corresponding to the water vapor discharge hole according to the present invention) that communicates the inside and outside of the medium diameter part 11b (pump housing 2) at a position facing the drain hole 13 on the peripheral wall of the medium diameter part 11b. However, it is formed so as to penetrate along the Y-axis direction in FIG. It has become. In addition, at the circumferential position where the communication hole 15 is provided on the end surface of the large-diameter portion 11 a of the pump housing 2, a bowl-shaped shielding portion 16 extends in the axial direction so as to cover the communication hole 15. In addition, by covering the communication hole 15 with the shielding portion 16, the inconvenience that foreign matter or the like enters the pump housing 2 from the outside through the communication hole 15 is suppressed.

  One end of the drive shaft 3 faces the outside from one end of the pump housing 2, and the other end faces the outside from the other end of the pump housing 2. The drive shaft 3 has a predetermined axial width from the axial position corresponding to the drain hole 13 or the communication hole 15 toward one end side from the fitting position of the mechanical seal 10 toward the one end side. An annular notch groove 3a is provided along the circumferential direction. By providing the notch groove 3a in this manner, the coolant that has passed through the outer peripheral surface of the drive shaft 3 out of the cooling water that has flowed into the middle diameter portion 11b beyond the mechanical seal 10 will be described in detail. The flow is blocked by step portions 3b and 3c) which will be described later. That is, a part of the cooling water flowing from the pump chamber P side along the outer peripheral surface of the drive shaft 3 is cut off by the one end side step portion 3b of the notch groove 3a, and is not cut off by the one end side step portion 3b. The cooling water is blocked by the other end side step portion 3b of the notch groove 3a, and the flow of the cooling water to the pulley 4 side is suppressed by the notch groove 3a. It is dripped and stored in the drain chamber 12.

  Further, in particular, in the present embodiment, the one end side step portion 3b of the notch groove 3a is configured to be aligned in a straight line with the drain hole 13 and the communication hole 15 in the vertical direction. In other words, the communication hole 15 is arranged on the upper side in the vertical direction of the one end side step portion 3b and the drain hole 13 of the notch groove 3a. More specifically, a straight line formed by arranging the one end side step portion 3b of the cutout groove 3a, the drain hole 13 and the communication hole 15 is slightly inclined to the pulley 4 side with respect to the Y axis. The communication hole 15 is slightly closer to the pulley 4 in the X-axis direction than the hole 13.

  The pulley 4 is integrally formed in a substantially cylindrical shape by pressing a metal plate, and has a cylindrical base portion 4a configured to have a bottomed cylindrical shape so as to surround the small diameter portion 11c of the pump housing 2. A belt winding portion 4b that extends to the outer peripheral side of the cylindrical base portion 4a and serves to link with the crankshaft when the belt is wound around the outer periphery thereof, and a pump at the center of the cylindrical base portion 4a A recess is formed along the axial direction from the housing 2 side to the outside, and has a shaft fixing portion 4 c for fixing to the drive shaft 3. The shaft fixing portion 4 c is press-fitted into the outer periphery of one end portion of the drive shaft 3. Thus, it is fixed to the drive shaft 3. Here, the cylindrical base portion 4a is inserted into the outer periphery of the bearing 6 and is provided with a bearing support portion 4d for rotation support by the bearing 6, and extends radially inward from the outer edge of the bearing support portion 4d. As a result, it is arranged to face the outer surface of the bearing 6 and is composed of a side wall portion 4e (corresponding to a side wall according to the present invention) for connecting the bearing support portion 4d and the shaft fixing portion 4c. After the bearing 6 (an outer ring 6b described later) is press-fitted into the inner periphery, the bearing 6 (the inner ring 6a described later) is press-fitted into the outer periphery of the small diameter portion 11c of the pump housing 2, thereby being assembled to the pump housing 2. Become.

  Further, the side wall 4e of the pulley 4 has a plurality of discharge holes 17 (for the present invention) for discharging the cooling water flowing from the pump chamber P side into the small diameter portion 11c beyond the mechanical seal 10 and the like. (Corresponding to such a through hole) is formed through the X-axis direction in FIG. 3 at substantially equal intervals in the circumferential direction. In particular, each of the discharge holes 17 is configured such that the inner peripheral side thereof is opened on the inner peripheral side with respect to a first seal member 6d described later, so that the steam-like cooling water flowing into the small diameter portion 11c is first. Before reaching one seal member 6d, it is discharged to the outside through the discharge holes 17 concerned. In addition, by providing a plurality of these discharge holes 17, it is possible to efficiently discharge the cooling water in the pump 1.

  The cover member 5 is press-molded in a substantially cylindrical shape with a predetermined metal material having corrosion resistance such as aluminum or stainless steel, and as shown in FIG. 3, a cover that covers the cylindrical base portion 4a of the pulley 4 from the outside. A portion 5a, a cylindrical portion projecting in the axial direction in the central portion of the covering portion 5a, a fixing portion 5b for fixing to the pulley 4, and an outer peripheral region of the covering portion 5a. A substantially flat elastic contact portion 5c that elastically contacts the second side wall 4f, and the fixed portion 5b is fixed to the pulley 4 by being press-fitted into the outer periphery of the shaft fixing portion 4c of the pulley 4. Yes. The cover member 5 has an inner peripheral end pressed against the outer peripheral surface of the shaft fixing portion 4 c of the pulley 4, while the outer peripheral end is close to the inner peripheral surface of the belt winding portion 4 b of the pulley 4. The inner surface of the elastic contact portion 5c elastically contacts the outer surface of the second side wall 4f constituting the outer peripheral side wall of the pulley 4 via the seal member 18 (see FIG. 5). 5 is prevented from communicating inside and outside, and the flow of air (airflow) through the discharge holes 17 is suppressed. That is, the communication preventing means according to the present invention is constituted by the inner side surface of the elastic contact portion 5c, the seal member 18 and the outer side surface of the second side wall 4f.

  The seal member 18 is composed of a liquid gasket, and by adopting such a liquid material, good sealing performance can be obtained regardless of the accuracy of the surface roughness of the elastic contact portion 5c and the second side wall 4f. It is possible to secure. In other words, since the elastic contact portion 5c and the second side wall 4f are sufficient with low accuracy, the productivity of the pulley 4 and the cover member 5 is not reduced. In addition to the liquid material, a plate-like gasket or a ring-like gasket can also be adopted as the seal member 18. When a plate-like gasket is adopted, the seal member 18 is Since it is only necessary to be sandwiched between the elastic contact portion 5c and the second side wall 4f, it is possible to obtain a good assembling property, and when a ring-shaped gasket is employed, Since a smaller mounting area is sufficient, better assemblability than that of the plate-like gasket can be obtained.

  The bearing 6 is a so-called ball bearing with a seal, and is interposed between the outer peripheral surface of the small diameter portion 11c and the inner peripheral surface of the bearing support portion 4d, and is press-fitted and fixed to the outer peripheral surface of the small diameter portion 11c. The inner ring 6a, the outer ring 6b press-fitted to the inner peripheral surface of the bearing support 4d, and a plurality of rolling elements held in a pair of holding grooves provided opposite to each other between the inner and outer rings 6a, 6b. The first and second annular first and second rings are fixed to the inner peripheral edges of both ends of the ball 6c and the outer ring 6b, and block communication between the cylindrical space defined between the inner and outer rings 6a and 6b in the radial direction and the outside. It is comprised from the bearing seals 6d and 6e. And in such a bearing 6, while the 1st bearing seal 6d arrange | positioned at the one end part, the penetration | invasion into the said bearing 6 inside of the water | moisture content which flowed in into the small diameter part 11c from the medium diameter part 11b is suppressed, On the other end side, the second bearing seal 6e and the shielding plate 7 arranged in series with the second bearing seal 6e prevent foreign substances such as rainwater from entering the bearing 6 from the outside.

  The shielding plate 7 is formed in a substantially annular shape from a predetermined metal material having corrosion resistance such as aluminum or stainless steel, and is inserted into the pump housing 2 from the distal end side of the small diameter portion 11c. When the bearing 6 (inner ring 6a) is press-fitted into 11c, the other end of the bearing 6 is clamped and fixed between the inner ring 6a and the step portion 11d. The shielding plate 7 has an inner peripheral edge that abuts on the small diameter portion 11c, while an outer peripheral edge extends to a position close to the inner peripheral surface of the bearing support portion 4d of the pulley 4 so that rainwater, etc. The trouble that the foreign matter directly reaches the bearing 6 is suppressed.

  The impeller 8 is integrally formed by pressing a metal plate, and a base portion 8a formed in a substantially disc shape, and an outer peripheral side is cut and raised at a predetermined position in the circumferential direction of the base portion 8a. A plurality of blade portions 8b that are bent in the direction, and a cylindrical shaft portion 8c that is recessed along the axial direction from the pump housing 2 side to the engine block side at the center portion of the base portion 8a, The shaft portion 8 c is fixed to the drive shaft 3 by being press-fitted into the outer periphery of the other end portion of the drive shaft 3.

  Hereinafter, the characteristic operation of the water pump 1 according to the present embodiment will be described with reference to FIG.

  In the water pump 1, the pump housing 2 has entered the pump housing 2 beyond the mechanical seal 10 from the pump chamber P side by the communication hole 15 formed in the axially upper portion of the pump housing 2 in the axial direction (medium diameter portion 11 b). The cooling water (water vapor) is configured to be directly discharged, and the water vapor is temporarily stored in the drain chamber 12 provided in the vertical lower portion of the medium diameter portion 11b so as to discharge the holes 14 or the communication holes. 15 is configured to be capable of being indirectly discharged to the outside through 15.

  However, since the water pump 1 is provided with the discharge holes 17 communicating with the inside and outside of the pump housing 2 in the side wall portion 4e of the pulley 4 as in the prior art, the impeller 8 is provided inside the pump housing 2. An airflow flowing in the negative direction of the X-axis from the side to the bearing 4 side is generated, and at least the water vapor that has entered the pump housing 2 due to this airflow is discharged from the discharge holes 17 through the inner periphery of the small diameter portion 11c. It becomes. As a result, water vapor acts on the bearing 6 at the time of discharge from the respective discharge holes 17, and as a result, there is a possibility that moisture may enter the bearing 6.

  Therefore, in the present embodiment, the inner peripheral end (fixed portion 5b) of the cover member 5 is brought into pressure contact with the inner peripheral end (shaft fixing portion 4c) of the pulley 4, and the outer peripheral end of the cover member 5 is also contacted. The portion (elastic contact portion 5c) is configured to be elastically contacted to the outer peripheral side end portion (second side wall 4f) of the pulley 4 via the seal member 18, and the cover member 5 makes each discharge hole 17 liquid-tight. The cooling water that has entered the pump housing 2 is discharged to the outside through the discharge holes 14, the communication holes 15, and the like provided in the peripheral wall of the medium diameter portion 11 b instead of the discharge holes 17. I tried to do it.

  With such a configuration, according to the water pump 1 according to the present embodiment, the water vapor that has entered the pump housing 2 is directly discharged to the outside through the communication hole 15 or is once drained. After being stored in 12, it is discharged to the outside through the discharge hole 14 or the communication hole 15, and there is no possibility of reaching the vicinity of the bearing 4 in which each of the discharge holes 17 is provided. As a result, it is possible to avoid failure of the bearing 6 due to moisture intruding into the bearing 6 and to improve the durability of the bearing 6.

  In addition, at this time, the communication hole 15 is arranged so as to be almost directly above the step 3b and the drain hole 13 of the drive shaft 3 and substantially in a straight line with the step 3b and the drain hole 13. The water vapor evaporated on the drive shaft 3 after entering the pump housing 2 and the water vapor rising from the drain chamber 12 through the drain hole 13 do not interfere with the peripheral wall of the pump housing 2 (especially the peripheral wall of the medium diameter portion 11b). Thus, it can be smoothly discharged to the outside through the communication hole 15. Thereby, it is possible to effectively suppress the inconvenience that the cooling water that has entered the pump housing 2 reaches the bearing 6 through the small diameter portion 11c.

  Further, since the communication hole 15 is slightly biased toward the pulley 4 side with respect to the drain hole 13 and is obliquely directed toward the pulley 4 side, the cooling water rising from the drain chamber 12 or the like The cooling water in the internal space S can be discharged more smoothly. As a result, the cooling water that has entered the pump housing 2 is effectively suppressed against the inconvenience of reaching the bearing 6.

  FIG. 6 shows a second embodiment of the water pump according to the present invention, in which the closing means of each discharge hole 17 is changed. Since the basic configuration other than this configuration is the same as that of the first embodiment, the same configuration and operation as the first embodiment are denoted by the same reference numerals as those of the first embodiment. Description is omitted.

  That is, in the present embodiment, the cover member 5 according to the first embodiment is eliminated, and each of the discharge holes 17 is directly closed by the plug member 20. The plug member 20 is integrally formed of, for example, a rubber material. The plug member 20 is inserted into each of the discharge holes 17 to close the discharge holes 17 and a restriction for restricting the amount of insertion of the plugs 21. Part 22. Here, the outer diameter of the blocking portion 22 is set to be slightly larger than the inner diameter of each discharge hole 17, and the outer peripheral surface elastically contacts the inner peripheral surface of each discharge hole 17. The discharge hole 17 is liquid-tightly closed by the plug member 20.

  Therefore, according to the present embodiment, the discharge holes 17 can be blocked more effectively by directly closing the discharge holes 17 with the plug members 20. Thereby, the air-blocking property through the discharge holes 17 is improved, and the inconvenience that the cooling water entering the pump housing 2 reaches the bearing 6 can be more effectively suppressed.

  The present invention is not limited to the configuration of each of the above-described embodiments. For example, the shape of the cover member 5 and the plug member 20, and the positions and opening directions of the communication holes 15, the drain holes 13, the discharge holes 14, etc. The pump 1 can be freely changed according to the application target, the usage environment, and the like.

  Moreover, in the said 1st Embodiment, when comprising the communication inhibition means based on this invention using the cover member 5, the seal member 18 is an auxiliary member and is not an essential structure. In other words, when necessary sealing performance can be obtained, it is of course possible to configure the communication inhibiting means by directly elastically contacting the elastic contact portion 5c of the cover member 5 with the second side wall 4f. In such a case, since the number of components can be reduced, the productivity is improved and the cost is reduced.

  Hereinafter, technical ideas other than those described in the scope of claims understood from the respective embodiments will be described.

(A) In the water pump according to claim 1 or 2,
A notch is provided between the position where the mechanical seal is disposed on the drive shaft and the position where the pulley is disposed, and has an outer diameter smaller than the position where the mechanical seal is disposed. Having a notch groove formed and a step provided at least at one end of the notch groove;
A drain chamber that can store a predetermined amount of cooling water and a drain hole that guides cooling water dripped from the step portion to the drain chamber are provided below the step portion in the pump housing in the vertical direction. And water pump.

  With this configuration, the cooling water that has entered the pump housing beyond the mechanical seal is blocked by the notch groove or the stepped portion and stored in the drain chamber through the drain hole. Can be avoided from flowing to one end of the drive shaft and acting on the bearing.

(B) In the water pump according to claim 3,
The water pump according to claim 1, wherein the water vapor discharge hole is provided substantially vertically above the drain hole.

  By comprising in this way, the water vapor | steam which goes up through a drain hole from a drain chamber can be efficiently discharged | emitted outside, without making it interfere with a pump housing internal peripheral surface.

(C) In the water pump according to claim 3,
The water pump according to claim 1, wherein the water vapor discharge hole is provided substantially vertically above the stepped portion.

  By comprising in this way, it becomes possible to suppress interference with the pump housing inner peripheral surface at the time of the cooling water adhering to a drive shaft evaporating, and the said cooling water can be discharged | emitted efficiently.

(D) In the water pump according to claim 1,
The water pump is characterized in that the communication inhibiting means is configured by contact between the cover member and the pulley.

  By comprising in this way, since the said communication inhibition means can be easily comprised only with a cover member, it is comparatively cheap and is used for suppression of the rise in manufacturing cost.

(E) In the water pump according to claim 1,
The water pump is characterized in that the communication inhibiting means is constituted by a liquid gasket interposed between the cover member and the pulley.

  With such a configuration, sealing can be performed regardless of the shape and surface roughness of the cover member, so that the degree of freedom in designing the cover member including processing accuracy can be improved, and productivity and manufacturing can be improved. This is used to control the rise in costs.

(F) In the water pump according to claim 1,
The water pump is characterized in that the communication inhibiting means is constituted by a plate-like gasket interposed between the cover member and the pulley.

  By comprising in this way, since it can seal only by pinching the said plate-shaped gasket, favorable assembly | attachment property is obtained compared with the case where a liquid gasket is employ | adopted.

(G) In the water pump according to claim 1,
The water pump is characterized in that the communication inhibiting means is constituted by a ring-shaped gasket interposed between the cover member and the pulley.

  With such a configuration, sealing can be performed simply by sandwiching the ring-shaped gasket, and therefore, better assemblability can be obtained as compared with the case where a liquid gasket is employed. Furthermore, it is possible to obtain better assemblability than a plate-like gasket in that the attachment range is narrow.

(H) In the water pump according to claim 2,
The water pump according to claim 1, wherein the communication inhibiting means is provided for each through hole.

DESCRIPTION OF SYMBOLS 1 ... Water pump 2 ... Pump housing 3 ... Drive shaft 4 ... Pulley 4a ... Cylindrical base part 4e ... Side wall part (side wall)
4f ... 2nd side wall (communication inhibition means)
5 ... cover member 5c ... elastic contact portion (communication inhibiting means)
6 ... Bearing 8 ... Impeller 10 ... Mechanical seal 15 ... Communication hole (water vapor discharge hole)
17 ... discharge hole (through hole)

Claims (2)

A pump housing having a cylindrical portion on one axial end side;
A pulley having a cylindrical base portion configured to surround the cylindrical portion, rotatably supported on the outer periphery of the cylindrical portion, and rotated by transmission of power from the outside;
A bearing composed of an inner ring fixed to the outer periphery of the cylindrical portion, an outer ring fixed to the inner periphery of the cylindrical base, and a rolling element interposed between the inner and outer rings;
One end portion thereof is provided so as to be rotatable integrally with the pulley, and a drive shaft that is inserted and arranged along the axial direction on the inner peripheral side of the pump housing;
An impeller provided at the other end of the drive shaft so as to be integrally rotatable with the drive shaft;
A mechanical seal interposed between the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the drive shaft;
A through hole provided in at least one side wall facing the bearing in the cylindrical base, and communicating with the inside and outside of the pump housing;
A water vapor discharge hole provided on the inner peripheral surface of the pump housing on one end side of the drive shaft rather than the mechanical seal, and discharges water vapor to the outside;
A cover member provided to cover the through hole at the outer end of the pulley;
A water pump comprising: a communication inhibiting means for holding an outer peripheral area of the through hole in the pulley and the cover member in close contact with each other and inhibiting communication with the outside of the through hole. A pump housing having a cylindrical portion on one axial end side;
A pulley having a cylindrical base portion configured to surround the cylindrical portion, rotatably supported on the outer periphery of the cylindrical portion, and rotated by transmission of power from the outside;
A bearing composed of an inner ring fixed to the outer periphery of the cylindrical portion, an outer ring fixed to the inner periphery of the cylindrical base, and a rolling element interposed between the inner and outer rings;
One end of the drive shaft is fixed to the pulley, and the drive shaft is inserted and arranged along the axial direction on the inner peripheral side of the pump housing;
An impeller provided at the other end of the drive shaft so as to be integrally rotatable with the drive shaft;
A mechanical seal interposed between the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the drive shaft;
A through hole provided in at least one side wall facing the bearing in the cylindrical base, and communicating with the inside and outside of the pump housing;
A water vapor discharge hole provided on the inner peripheral surface of the pump housing on one end side of the drive shaft rather than the mechanical seal, and discharges water vapor to the outside;
A water pump, comprising: a communication inhibiting means that is provided in the through hole and inhibits communication with the outside of the through hole.

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