JP2019196721A - Water pump - Google Patents

Abstract

To provide a water pump capable of suppressing leakage of a fluid from a housing chamber for housing an impeller.SOLUTION: A water pump 1 includes an impeller 10 integrally and rotatably supported with a rotating shaft 50, a housing chamber 20 for housing the impeller 10, a supply chamber 30 for supplying a fluid of a second pressure as a pressure higher than a first pressure as a pressure inside of the housing chamber 20, and a mechanical seal 40 provided with a seal member 77 having a first surface 41 on which the first pressure is acted and a second surface 42 on which the second pressure is acted, between the housing chamber 20 and the supply chamber 30, and disposed slidably to the rotating shaft 50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a water pump that circulates fluid by rotation of an impeller.

  Conventionally, when circulating a fluid, a water pump has been used. Some water pumps of this type circulate a fluid by rotating a rotating shaft fixed so that the impeller rotates integrally (for example, Patent Document 1).

  Patent Document 1 describes a water pump used for a water-cooled engine or the like. In this water pump, a rotating shaft is rotatably supported in a pump body via a bearing. A driving pulley is fixed to one end of the rotating shaft by bolting via a pulley bracket, and an impeller is fixed to the other end of the rotating shaft by press fitting or the like. An impeller rotates with a rotating shaft to circulate cooling water to cool a water-cooled engine or the like. An annular mechanical seal is disposed in the region between the impeller and the bearing and on the outer periphery of the rotating shaft. A space is formed between the mechanical seal and the bearing, and cooling water leaked through the mechanical seal from the storage chamber in which the impeller is stored flows into the space. In this space, a drain discharge hole for discharging the liquid phase cooling water is formed, and the liquid phase cooling water is collected in the storage space through the drain discharge hole. On the other hand, a vapor discharge hole for discharging gas-phase cooling water (water vapor) is also formed in the space. Thereby, the cooling water leaking from the mechanical seal is suppressed from flowing out of the water pump.

JP 2008-169763 A

  During the operation of the water pump, the pressure in the storage chamber in which the impeller is stored becomes higher than the pressure outside the storage chamber (space). For this reason, even if it is comprised so that the cooling water which leaked through the mechanical seal like the technique of patent documents 1 may be collected, it is between the storage room and the outside of the storage room during operation of the water pump. Since the pressure difference is generated, the leakage of the cooling water from the mechanical seal to the space cannot be fundamentally eliminated. Therefore, when the leakage of cooling water increases due to wear of the mechanical seal, the cooling water may enter the bearing and the bearing may break down. Furthermore, when cooling water leaks through a bearing, parts other than the bearing may also break down.

  Therefore, a water pump capable of suppressing fluid leakage from the storage chamber that stores the impeller is required.

  The characteristic configuration of the water pump according to the present invention includes an impeller that is supported so as to rotate integrally with a rotating shaft, a storage chamber that stores the impeller, and a pressure higher than a first pressure that is a pressure inside the storage chamber. A seal member having a supply chamber to which a fluid having a second pressure is supplied, a first surface on which the first pressure acts between the storage chamber and the supply chamber, and a second surface on which the second pressure acts And a mechanical seal disposed so as to be slidable with respect to the rotating shaft.

  In general, the cause of the water pump fluid leaking outside from the storage chamber is mainly due to (1) a decrease in the seal area due to wear of the sliding surface of the mechanical seal, and (2) a mechanical formed by foreign matter mixed in the fluid. This is considered to be a scratch on the sliding surface of the seal, and (3) biting of foreign matter into the seal member of the mechanical seal. Therefore, with the above-described characteristic configuration, even when the sealing performance is deteriorated due to wear of the sliding surface of the mechanical seal or damage to the sliding surface, the second pressure higher than the first pressure in the housing chamber is applied to the sealing member. Therefore, the sealing performance of the sliding surface of the mechanical seal can be maintained. Therefore, fluid leakage from the storage chamber side to the supply chamber side via the mechanical seal can be suppressed. Further, with such a configuration, a configuration that communicates with the outside, such as a conventional vapor discharge hole, is not necessary, and foreign matter can be prevented from entering the water pump. Therefore, generation | occurrence | production of the damage | wound by a mechanical seal biting in a foreign material can be prevented.

  In addition, it is preferable that the second pressure fluid is supplied to the supply chamber from a supercharger.

  With such a configuration, the fluid having the second pressure can be easily generated. In addition, since the supercharger can be used together with a device provided with a water pump, it is not necessary to newly provide it and can be realized at low cost.

  In addition, it is preferable that the second surface is opposed to the first surface and has an area larger than the area of the first surface.

  With such a configuration, the seal member can be pressed from the second surface. Therefore, it becomes possible to improve the sealing performance of the seal member.

It is a sectional side view of a water pump. It is a sectional side view of a mechanical seal.

  The water pump according to the present invention is configured so that the fluid does not leak from the storage chamber in which the impeller is stored. Hereinafter, the water pump 1 of the present embodiment will be described. FIG. 1 is a side sectional view of a water pump 1 according to the present embodiment. FIG. 2 is a side sectional view of the mechanical seal 40. The water pump 1 includes an impeller 10, a storage chamber 20, a supply chamber 30, and a mechanical seal 40.

  The impeller 10 is supported so as to be rotatable integrally with the rotary shaft 50. The rotary shaft 50 receives a rotational force for operating the water pump 1 from, for example, an internal combustion engine or a motor. The rotational force from the internal combustion engine or motor can be input via the pulley 51. The impeller 10 is connected and fixed to the rotary shaft 50, and the impeller 10 is configured to rotate together with the rotary shaft 50 when a rotational force is input to the rotary shaft 50.

  The storage chamber 20 stores the impeller 10. The accommodating chamber 20 is a space that encloses the impeller 10 formed by the pump housing 21. The storage chamber 20 is provided with an inlet 22 through which a fluid is introduced and an outlet 23 through which the fluid flows out. In the example of FIG. 1, the inlet 22 is provided on the outer side in the axial direction of the rotating shaft 50, and the outlet 23 is provided on the outer side in the radial direction of the impeller 10. As the impeller 10 rotates, fluid is sucked from the inlet 22 and discharged from the outlet 23.

  Pressure due to fluid (“inside pressure” to be described later) is generated inside the storage chamber 20. The pressure inside the storage chamber 20 corresponds to the pressure of the fluid pressurized according to the rotation of the impeller 10 when the water pump 1 is operating, and when the water pump 1 is not operating. The pressure of the fluid introduced into the storage chamber 20 or the pressure of the air in the storage chamber 20 corresponds. Such a pressure is referred to as a first pressure in this embodiment.

  The supply chamber 30 is supplied with a fluid having a pressure higher than the first pressure. In the present embodiment, such a pressure higher than the first pressure is referred to as a second pressure. The supply chamber 30 is formed in the pump housing 21 similarly to the storage chamber 20. In the present embodiment, the fluid having the second pressure is supplied from the supercharger 31 to the supply chamber 30. At this time, it is preferable that a tank 32 and a solenoid valve 33 for storing the fluid of the second pressure from the supercharger 31 are provided between the supercharger 31 and the supply chamber 30. The tank 32 may be provided with a check valve 34 so that the fluid at the second pressure in the tank 32 does not flow backward to the supercharger 31 side. The electromagnetic valve 33 is a valve that can be switched between an open state and a closed state by control. The electromagnetic valve 33 may be opened, for example, every predetermined time so that the pressure in the supply chamber 30 does not become lower than the first pressure. Of course, the pressure in the supply chamber 30 may be detected, and the electromagnetic valve 33 may be opened according to the detection result. As a result, the fluid having the second pressure can be supplied to the supply chamber 30.

  The mechanical seal 40 is fixed to the pump housing 21 and is slidable with respect to the rotation shaft 50. As shown in FIG. 2, the mechanical seal 40 includes a first fixing member 71, a second fixing member 72, a third fixing member 73, a fourth fixing member 74, a first supporting member 75, a second supporting member 76, and a first fixing member. A seal member 77 (an example of a “seal member”) and a second seal member 78 are provided. In this embodiment, the 1st fixing member 71, the 2nd fixing member 72, the 3rd fixing member 73, and the 4th fixing member 74 are comprised using the metal material, and the 1st supporting member 75 and the 2nd supporting member 76 are comprised. Is made of an elastic material. Moreover, the 1st seal member 77 and the 2nd seal member 78 are comprised using an abrasion-resistant material. Of course, these can also be constructed using materials having different characteristics.

  The first fixing member 71 is fitted and inserted into the pump housing 21 and fixed to the pump housing 21. The second fixing member 72 and the third fixing member 73 sandwich the first support member 75 with the first fixing member 71. The fourth fixing member 74 has a gap (forms a “communication path 35” described later) between the first fixing member 71 and is slidable with respect to the rotation shaft 50. The fourth fixing member 74 is bent toward the radially outer side so that one end portion 74 </ b> A is located radially outside the radially inner portion 71 </ b> A of the first fixing member 71. Thereby, the fourth fixing member 74 is prevented from coming off from the first fixing member 71. The fourth fixing member 74 supports the second support member 76.

  The first seal member 77 and the second seal member 78 are sandwiched between the first support member 75 and the second support member 76 so as to form a sliding surface perpendicular to the rotation shaft 50 by contacting. The first seal member 77 is provided so as to have a gap 36 between it and the first fixing member 71, and the second seal member 78 is provided so as to have a gap 37 between it and the fourth fixing member 74.

  When the rotating shaft 50 rotates in such a configuration, the first pressure acts on the first surface 41 of the first seal member 77, and the second pressure acts on the second surface 42. Here, the 1st surface 41 is a surface which faces the storage chamber 20 side among the surfaces which the 1st seal member 77 has. The fluid of the first pressure presses the first surface 41 and circulates in the space formed by the second seal member 78, the fourth fixing member 74, and the second support member 76 through the gap 37, and the slide The second seal member 78 is also pressed from the surface opposite to the moving surface. Of the surfaces of the first seal member 77, the second surface 42 is a surface that communicates with the communication path 35 and the gap 36 and forms a space together with the first fixing member 71 and the first support member 75. The fluid of the second pressure flows through the space formed by the second surface 42, the first fixing member 71, and the first support member 75 via the communication path 35 and the gap 36, and passes through the second surface 42 through the second surface 42. Press toward the seal member 78.

  In the example of FIG. 2, the second pressure received by the second surface 42 is configured to be greater than the sum of the first pressure received by the first surface 41 and the second pressure received by the third surface 43. . Thereby, the 1st seal member 77 can be pressed to the 2nd seal member 78 side with the force according to the pressure-receiving difference. Therefore, the sealing performance of the sliding surface between the first sealing member 77 and the second sealing member 78 can be enhanced, and the leakage of fluid in the storage chamber 20 via the sliding surface can be suppressed. Although the first seal member 77 is pressed toward the second seal member 78, the first support member 75 and the first support member 75 are formed of an elastic material as described above. The sealing performance between the first seal member 77 and the first support member 75 does not leak. Even if the strength of the pressing force of the second seal member 78 by the first seal member 77 is large, the second support member 76 is formed of an elastic material, so that the pressing force by the first seal member 77 is the second support. It is absorbed by the member 76 and the sliding of the second seal member 78 with respect to the first seal member 77 is not hindered.

  Here, the second surface 42 is preferably opposed to the first surface 41 and has a larger area than the area of the first surface 41. As a result, the pressure receiving area of the second pressure can be made larger than the pressure receiving area of the first pressure with respect to the first seal member 77, so that it acts on the second surface 42 rather than the force acting on the first surface 41. The power to do can be increased. Therefore, the sealing performance between the first seal member 77 and the second seal member 78 can be improved.

  Further, as described above, the mechanical seal 40 is slidable with respect to the rotary shaft 50 by the fourth fixing member 74 and is disposed with a pressing force. For this reason, the 4th fixing member 74 seals between the rotating shafts 50, and does not connect the storage chamber 20 and the supply chamber 30. However, there may be a case where a minute gap 60 is unintentionally caused by the above (1) to (3) described as the cause of the fluid of the water pump leaking outside from the storage chamber. However, even in the case of the minute gap 60, the fluid in the storage chamber 20 is supplied because the fluid in the second pressure on the supply chamber 30 side acts on the fluid at the first pressure on the storage chamber 20 side. Leaking to the chamber 30 side can be suppressed.

  As described above, the water pump 1 is configured, and the fluid circulated by the water pump 1 can be prevented from leaking from the storage chamber 20 to the supply chamber 30.

[Other Embodiments]
In the above-described embodiment, it has been described that the fluid of the second pressure is supplied from the supercharger 31 to the supply chamber 30. Instead of the supercharger 31, it is also possible to supply a fluid having the second pressure from a compressor that outputs a compressed fluid such as a compressor.

  Further, in the above embodiment, it has been described that the tank 32 and the electromagnetic valve 33 are provided between the supercharger 31 and the supply chamber 30, and the check valve 34 is provided in the tank 32. However, a configuration without the tank 32 and the electromagnetic valve 33 is also possible. In this case, a check valve 34 may be provided in the supply chamber 30 so that the fluid having the second pressure is supplied from the supercharger 31 to the supply chamber 30. Even in such a case, it is possible to achieve the same effect as the above embodiment.

  In the above embodiment, the second surface 42 is described as being opposed to the first surface 41 and having an area larger than the area of the first surface 41. However, the second surface 42 and the first surface 41 may be provided so as not to face each other. Further, the area of the second surface 42 can be configured to be the same as the area of the first surface 41, and the area of the second surface 42 is configured to be smaller than the area of the first surface 41. Is also possible. In any case, the first seal member 77 is pressed toward the second seal member 78 with a force corresponding to the pressure difference, thereby sealing the sliding surface between the first seal member 77 and the second seal member 78. It is good to improve the sex.

  The present invention can be used in a water pump that allows fluid to flow through rotation of an impeller.

1: Water pump 10: Impeller 20: Storage chamber 30: Supply chamber 31: Supercharger 40: Mechanical seal 41: First surface 42: Second surface 50: Rotating shaft 77: First seal member (seal member)

Claims (3)

An impeller that is supported so as to rotate integrally with the rotating shaft;
A storage chamber for storing the impeller;
A supply chamber to which a fluid having a second pressure that is higher than a first pressure that is a pressure inside the storage chamber is supplied;
A seal member having a first surface on which the first pressure acts and a second surface on which the second pressure acts is provided between the storage chamber and the supply chamber, and is slidable with respect to the rotating shaft. A mechanical seal to be arranged;
Water pump equipped with.   The water pump according to claim 1, wherein the fluid having the second pressure is supplied to the supply chamber from a supercharger.   The water pump according to claim 1 or 2, wherein the second surface is opposed to the first surface and has a larger area than the area of the first surface.

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