JP2014185616A - Water pump - Google Patents

Abstract

A water pump capable of reducing the size of an apparatus while reliably discharging leaked cooling water.
A rotating shaft supported on a housing via a bearing, an impeller provided at one end of the rotating shaft and circulating a cooling water, and a pulley provided at the other end of the rotating shaft. And a seal member 18 provided between the impeller 15 and the bearing 13 of the rotating shaft 14 over the housing 11 to suppress leakage of cooling water to the outside, and the housing 11 in a state of opening to the side surface of the bearing 13. A drainage passage 19 for discharging cooling water leaked from the seal member 18 and a communication passage 21 formed between the bearing 13 and the housing 11 and communicating with the drainage passage 19 from the end of the bearing 13. I have.
[Selection] Figure 1

Description

  The present invention relates to a water pump useful for cooling used in an internal combustion engine (engine) such as an automobile.

  A conventional water pump includes a rotating shaft supported by a housing via a bearing, an impeller provided at one end of the rotating shaft for circulating cooling water, a pulley provided at the other end of the rotating shaft, and a rotating shaft. A mechanical seal provided across the housing between the impeller and the bearing for suppressing leakage of cooling water to the outside, and a drainage channel provided in the housing for discharging the cooling water leaked from the mechanical seal. Are known (for example, see Patent Document 1).

  In this water pump, a space for connecting to the drainage channel is provided in a region of the housing opposite to the impeller across the mechanical seal.

JP 2008-112488 A

This type of water pump is usually mounted on the outer surface of the engine block.
Therefore, the pulley, the bearing, and the space are the main factors that determine the size of the water pump along the rotation axis direction. Due to the property of rotating the pulley from the crank pulley via the timing belt, the external dimensions of the pulley are determined to some extent. For this reason, the dimension of the bearing and the space in the direction of the rotation axis is an important factor in making the device compact.

However, the conventional water pump has a space for guiding the cooling water from the mechanical seal to the drainage channel. When the dimension of the space in the direction of the rotation axis is reduced, the bearing blocks the drainage passage, and the cooling water that has lost its place of entry enters the inside of the bearing. As a result, grease emulsification or metal rusting occurs, and in the worst case, the bearing is damaged.
An object of this invention is to provide the water pump which can attain size reduction of an apparatus, discharging the cooling water which leaked reliably in view of the said background.

  The characteristic configuration of the water pump according to the present invention includes a rotating shaft supported by a housing via a bearing, an impeller provided at one end of the rotating shaft and circulating cooling water, and provided at the other end of the rotating shaft. A pulley, a seal member provided between the impeller and the bearing of the rotating shaft, which is provided across the housing and prevents leakage of the cooling water to the outside, and is open to a side surface of the bearing. A drainage channel that is provided in the housing and discharges the cooling water leaked from the seal member; a communication channel that is formed between the bearing and the housing and communicates from the end of the bearing to the drainage channel; It is in the point with.

  According to this configuration, the cooling water leaked from the seal member is discharged to the drainage channel through the communication path. The drainage channel is formed so as to open on a side surface of the bearing, and further, the communication path is formed between the bearing and the housing. That is, the flow of the cooling water to the drainage channel is secured by the communication path.

  Therefore, it is not necessary to provide a separate space for connecting the drainage channel, so that the device in the direction of the rotation axis can be made compact. Moreover, since the communication path is provided between the bearing and the housing, that is, between the inner surface of the housing and the outer surface of the bearing, the processing is easy.

  Further, since the connection port between the communication path and the drainage path may be anywhere in the longitudinal direction of the bearing, the length of the communication path can be freely set so as to allow an assembly error in the rotation axis direction. Therefore, the bearing does not block the drainage channel, and the cooling water does not enter the bearing.

  In the water pump of the present invention, it is preferable that a plurality of the communication passages are provided in the circumferential direction of the bearing.

  By providing a plurality of communication paths as in this configuration, for example, the attitude of the bearing press-fitted into the housing can be arbitrarily set, so that there is no inconvenience that the drainage path and the communication path are not connected due to an assembly error. For this reason, the cooling water leaked from the sealing member can be reliably discharged.

  In the water pump of the present invention, it is preferable that the communication path is provided along a surface of the bearing and inclined with respect to the longitudinal direction of the rotating shaft.

  Since the communication path is inclined in the longitudinal direction of the rotating shaft, the bearing is difficult to come out of the housing. Therefore, durability against bearing loss is improved. Thereby, the dimension of the rotating shaft direction of a bearing can be made small, and the further compactization of an apparatus is achieved.

  In the water pump according to the present invention, the housing is provided with a steam hole that opens from above with respect to a side surface of the bearing so as to discharge the evaporated cooling water to the outside of the housing. It is preferable that at least one of the passages communicates with the steam hole.

The sliding surface of the seal member is lubricated with a thin film of cooling water, and water vapor flows out of the sliding surface into the housing even during normal sealing function, and is released to the outside through a steam hole provided in the housing. Is done.
According to this configuration, since at least one of the plurality of communication paths communicates as the steam path, it is not necessary to specially process the communication path connected to the steam hole. Therefore, a compact device can be efficiently obtained with respect to the rotation axis direction.

It is a longitudinal cross-sectional view which shows the principal part of the water pump in this embodiment. It is an expansion perspective view of the bearing periphery in FIG. It is an expansion perspective view of the bearing periphery in another embodiment.

  Hereinafter, embodiments of a water pump according to the present invention will be described with reference to the drawings. In the present embodiment, as an example, a description will be given as a water pump 1 for circulating cooling water equipped in a vehicle engine (an example of a drive mechanism). However, the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the invention.

  The water pump 1 circulates cooling water to a vehicle engine and a radiator (not shown). The cooling water is warmed by the heat generated by the engine, and cools the engine by releasing heat from the radiator.

As shown in FIG. 1, in the water pump 1, the housing 11 is fixed to the engine block 12 with bolts 27. A rotation shaft 14 is supported on the housing 11 via a bearing 13. An impeller 15 for circulating cooling water is provided at one end of the rotating shaft 14, and a pulley 16 is fixed to the other end via a pulley bracket 17. Although not shown, the pulley 16 is rotationally driven from the crank pulley via a timing belt.
In addition, between the impeller 15 and the bearing 13, a mechanical seal 18 (a seal member) is provided across the housing 11 and the rotary shaft 14 in order to prevent cooling water from leaking to the outside through a gap between the rotary shafts 14. An example) is provided.

The bearing 13 is composed of a rolling bearing, and includes a rolling part 23 formed of a spherical body, an outer ring part 22 on the outside via the rolling part 23, and lip seal parts 24 at both ends in the axial direction. Yes.
Grease is applied to the rolling portion 23 so that the rotating shaft 14 rotates smoothly. The lip seal portion 24 prevents grease from leaking out and iron scraps from entering the bearing 13. The bearing 13 is not limited to a rolling bearing, and may take any form such as a sliding bearing.

  When the rotating shaft 14 is driven by the pulley 16, the impeller 15 rotates and the cooling water is sucked from the cooling water inlet and discharged from the cooling water outlet. At this time, cooling water leaks between the mechanical seal 18 and the bearing 13 through a minute gap between the mechanical seal 18 and the rotating shaft 14.

Further, the sliding surface of the mechanical seal 18 is lubricated with a thin film of cooling water, and water vapor flows into the housing 11 from the sliding surface even when the sealing function is normally exhibited.
Hereinafter, the cooling water in the present embodiment will be described as including steam and a liquid component in which the steam is condensed.

  Cooling water that has entered from the mechanical seal 18 flows into a region of the housing 11 opposite to the impeller 15 across the mechanical seal 18.

  As shown in FIG. 1, the liquid component of the inflowing cooling water is disposed along the circumferential direction outside the rotating shaft 14, and passes through the drainage channel 19 to the reservoir 25 positioned below the vertical direction. Then discharged.

As shown in FIG. 2, the drainage channel 19 is provided in the housing 11 so as to open to the side surface of the bearing 13. The communication path 21 is formed between the bearing 13 and the housing 11 and communicates with the drainage channel 19 from the end of the bearing 13.
Therefore, the liquid component leaked from the mechanical seal 18 is discharged in the order of the communication path 21, the drainage path 19, and the reservoir 25.

The side of the reservoir 25 opposite to the impeller 15 is opened, and the plug 26 is press-fitted and fixed so that the liquid component is not discharged to the outside. A drain hole 29 communicating with the outside of the housing 11 is formed above the reservoir 25.
For this reason, the liquid discharged to the reservoir 25 does not basically flow out to the outside, but is discharged to the outside from the drain hole 29 only when the allowable storage amount of the reservoir 25 is exceeded. Moreover, since the liquid component discharged | emitted by the reservoir | reserver 25 is heat-transferred from the housing 11 which became high temperature, and becomes a vapor | steam, the reservoir | reserver 25 is formed by the volume which can ensure a predetermined | prescribed storage amount.
The plug 26 may be any plug as long as it seals the opening of the reservoir 25 by, for example, closing the opening of the reservoir 25 by screw fastening provided with a seal member. Further, evaporation may be promoted by providing a planar member with good water absorption inside the reservoir 25 and increasing the surface area.

The housing 11 is provided with a steam hole 20 that opens from the upper side in the vertical direction with respect to the side surface of the bearing 13. At least one of the communication passages 21 communicates with the steam hole 20, and steam in the cooling water is discharged to the outside in the order of the communication passage 21 and the steam hole 20.
At this time, since the steam is in direct contact with the bearing 13 and the housing 11 that are at a high temperature, the steam is prevented from being condensed and becoming liquid. Therefore, there is no waste in the outflow path of the steam, and the steam is efficiently discharged to the outside.

  In the present embodiment, a plurality of communication passages 21 are provided in the outer ring portion 22 in the circumferential direction of the bearing 13. For this reason, even if the posture in which the rotary shaft 14 and the bearing 13 are press-fitted and fixed to the housing 11 varies, at least one of the communication passages 21 always communicates with the drainage passage 19 and the steam hole 20. Accordingly, the degree of freedom of the mounting posture of the bearing 13 is increased, and an assembly error is allowed.

Further, the communication path 21 in the present embodiment is provided along the surface of the bearing 13 and inclined with respect to the longitudinal direction of the rotating shaft 14. That is, since the convex part along the surface of the bearing 13 is inclined, the engagement length between the convex part and the inner surface of the housing 11 is increased. Therefore, the resistance force increases in the direction in which the bearing 13 is pulled out, and the fitting force between the bearing 13 and the housing 11 increases.
Note that the communication path 21 may be subjected to a flat knurled or twill-shaped knurling process on the outer peripheral surface of the outer ring portion 22. By performing knurling, the communication path 21 can be easily formed.

[Another embodiment]
FIG. 3 shows another embodiment according to the present invention. Only a configuration different from the above-described embodiment will be described.
As shown in FIG. 3, the communication path 21 is formed in a groove shape extending to the middle part in the longitudinal direction of the rotary shaft 14 between the bearing 13 and the housing 11, and communicates with the drainage channel 19 and the steam hole 20. doing. In the present embodiment, since the groove can be easily formed by cutting the outer peripheral surface of the bearing 13, the processing cost can be reduced.

In addition, the communication path 21 may be provided with a groove in both the bearing 13 and the housing 11, or may be provided in either one.
Further, a plurality of communication paths 21 may be provided in the circumferential direction of the bearing 13 or may be inclined in the longitudinal direction of the bearing 13. Since the effect by these is the same as that of the above-mentioned embodiment, it abbreviate | omits.

[Other Embodiments]
(1) In the above embodiment, as shown in FIG. 2, the plurality of communication passages 21 are provided over the outer periphery of the outer ring portion 22, but are connected to the drainage channel 19 and the steam hole 20 in the surface of the outer ring portion 22. Knurling may be applied only in the vicinity. The processing cost can be reduced as compared with the case of processing over the outer periphery.
(2) In the above embodiment, the drain hole 29 is formed in the housing 11. However, the drain hole 29 may be formed in the plug 26 attached to the opening of the reservoir 25.

  The water pump according to the present invention can be used for a water pump used for a wide range of cooling objects in various vehicles.

DESCRIPTION OF SYMBOLS 1 Water pump 11 Housing 13 Bearing 14 Rotating shaft 15 Impeller 16 Pulley 18 Mechanical seal (seal member)
19 Drainage channel 20 Steam hole 21 Communication channel

Claims (4)

A rotating shaft supported by a housing via a bearing;
An impeller provided at one end of the rotating shaft for circulating cooling water;
A pulley provided at the other end of the rotating shaft;
A seal member that is provided across the housing between the impeller and the bearing of the rotating shaft and suppresses leakage of the cooling water to the outside;
A drainage channel that is provided in the housing in a state of opening to a side surface of the bearing, and that discharges the cooling water leaked from the seal member;
A water pump comprising: a communication passage formed between the bearing and the housing and communicating with the drainage channel from an end portion of the bearing.   The water pump according to claim 1, wherein a plurality of the communication passages are provided in a circumferential direction of the bearing.   The water pump according to claim 2, wherein the communication path is provided along a surface of the bearing and inclined with respect to a longitudinal direction of the rotation shaft.   The housing is provided with a steam hole that opens from above on the side surface of the bearing so as to discharge the evaporated cooling water to the outside of the housing, and at least one of the plurality of communication passages is the steam hole. The water pump according to claim 2, wherein the water pump communicates with the water pump.

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