JPH08291793A - Vane pump - Google Patents

Abstract

PURPOSE: To improve workability of a drain passage for refluxing leaking oil which is cumulated on a shaft supporting part from a pump chamber to a pump suction side passing a drive shaft. CONSTITUTION: A pump discharge side pressure chamber 25 is formed on a pressure plate 21 side in the housing space 14 of a pump constituting element 13 in pump bodies 11, 12. A pump suction side passage 27 is formed on a side plate 20 side. A drive shaft 16 which is journalled to a pump bodies 11, 12 and the shaft hole 11a of the side plate 20 is arranged to rotary-drive a rotor 15 which is arranged on an inner end. A drain passage for refluxing leaking fluid from a pump chamber to a pump suction side passage passing the circumference of a drive shaft 16, is formed between a body shaft hole and the outer circumferential part of the drive shaft 16 and in the space 36 which is formed on the end side inner than a seal member 35, by a recessed groove 40 arranged on an inner surface which is faced to a body housing space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vane pump used in, for example, a power steering device for reducing a steering wheel operating force of an automobile.

[0002]

2. Description of the Related Art This type of vane pump is used, for example, as a hydraulic power source in a power steering device, and many types of vane pumps having various structures have been proposed.

An example thereof will be briefly described with reference to FIG. 5. A vane pump generally designated by reference numeral 10 is a front body 11 and a rear body 12 which constitute a pump body.
It has. The rear body 12 has a substantially cup shape, and a storage space 14 for storing and arranging the pump component 13 therein is formed therein. The rear body 12 is integrated as a pump body by combining the front body 11 so as to close the open end of the storage space 14.

The front body 11 has a bearing 1 in a state in which a drive shaft 16 for rotatably driving a rotor 15 as a rotor of a pump component 13 from the outside penetrates the front body 11.
It is rotatably supported by 6a and 16b (ball bearing and needle bearing in this example).

Reference numeral 17 has a substantially elliptical inner cam surface 17a in which the rotor 15 having the vanes 15a is housed and arranged. A pair of pump chambers 18, 18 (only one of which is provided between the cam surface 17a and the rotor 15). The cam cartridge 17 forms a pump cartridge 19 by the cam ring 17 and the rotor 15 having the vanes 15a.

Reference numeral 20 denotes a side plate laminated on the front body 11 side of the pump cartridge 19 in a pressure contact state, and 21 denotes a rear body 1 of the pump cartridge 19.
The pressure plates are laminated on the second side in a pressure contact state, and the pump component 13 is constituted by the plates 20, 21 and the pump cartridge 19. Reference numeral 22 denotes the front body 1 for positioning the plates 20 and 21 and the cam ring 17 in the rotational direction.
A positioning pin 23, which is planted on the first side, connects these plates 20, 21 and the cam ring 17 to the front body 11
Shows the bolts that are integrated and fixed to the side.

Reference numeral 25 denotes a storage space 14 for the rear body 12.
In the pressure chamber on the pump discharge side that is formed on the bottom side in
The pressure on the discharge side of the pump is applied to the pressure plate 21. Numeral 26 designates a pump chamber 18 in this pump discharge side pressure chamber 25.
It is a passage on the pump discharge side that is formed in the pressure plate 21 that guides the pressure oil from.

Reference numeral 27 denotes a pump suction side passage formed in the rear body 12 and the front body 11 so as to guide the suction side fluid from the suction port 28 provided in a part of the rear body 12 to the pump chamber 18, and this pump suction side Side passage 2
Although not shown in detail in FIG. 7, a pump suction opening 29 (pump) formed in the side plate 20 is guided downward in the drawing by a bifurcated passage that bypasses the penetrating portion of the drive shaft 16 in the front body 11. Suction side passage groove)
It is connected to the pump chamber 18 via.

A flow control valve 30 is provided inside the rear body 12 and is connected to a pressure chamber 25 on the pump discharge side in the space 14 through a passage 30a.
The discharge fluid from the pump chamber 18 is controlled to a predetermined flow rate by selectively connecting to the pump suction side passage 27 near the pump chamber 8. Reference numeral 31 is a discharge port for feeding the remaining part of the flow returned to the suction side by the flow control valve 30 to hydraulic equipment such as a power steering device (not shown) (PS in the figure). Is the rear body 12
Is provided on the side of the storage space 14 with a metering orifice 31a at the connection with the storage space 14.

As is apparent from FIG. 5, the vane pump 10 also has components other than those described above, but since these are widely known in the related art, a detailed description thereof will be omitted. .

The vane pump 10 having the above structure
According to the above, the rotor 15 is rotationally driven by the drive shaft 16 while moving the vane 15a in and out, so that the pressure oil as the working fluid from the suction port 28 is sucked into the pump chamber 18 through the passage 27 and the opening 29. Further, after being discharged from the discharge side passage 26 to the pump discharge side pressure chamber 25, at a predetermined pressure or less, the entire amount is discharged from the discharge port 31 to the power steering device PS or the like to be supplied. Further, at a predetermined pressure or higher, a part of the pressure oil is recirculated to the suction side by the flow control valve 30, and the remaining pressure oil flows from the pump discharge side pressure chamber 25 to the clearance passage between the outer peripheral portion of the pump component 13 and the inner wall portion of the storage space 14. 32, and further, a metering orifice 31a opening therein, and is discharged from the discharge port 31.

[0012]

According to the vane pump 10 having the above-described conventional structure, the pressure oil may leak to the outside of the body through the drive shaft 16 from the pump chamber 18 in the pump cartridge 19. For this reason, conventionally, it has been generally practiced to interpose an oil seal 35 between the bearings 16a and 16b in the shaft hole 11a of the front body 11 which pierces and pivotally supports the drive shaft 16. .

Further, in the vane pump 10 described above, it is accumulated in a space 36 formed between the shaft hole 11a of the body 11 and the outer peripheral portion of the drive shaft 16 on the inner end side of the portion where the oil seal 35 is provided. Conventionally, a drain hole 37 is provided as a drain passage for returning the pressure oil to the suction side of the pump. Such leakage of pressure oil is caused by the pump chamber 18 and the rotor 15 and each plate 2
It is generated through the shaft 16 and the shaft holes 20a and 11a through which the shaft 16 penetrates. When such a drain hole 37 is provided, the pressure oil accumulated in the space 36 inside the oil seal 35 can be appropriately collected on the suction side, and the bearing function of the bearing 16b in the space 36 can be secured. There is.

However, conventionally, such a drain hole 37 is formed.
Is the oil seal 3 of the shaft hole 11a of the front body 11.
It is formed by drilling holes obliquely inclined from the hole wall inside 5 to the pump suction side passage 27 in the body 11, and this hole drilling is troublesome, and the number of processing steps increases, It was a cause of high cost. That is, this drill hole machining is performed in the axial hole 1 of the front body 11.
A normal drill for drilling cannot be used because it must be performed obliquely from the outer end side of 1a. this is,
This is because a normal drill cannot be used because there is a front end wall portion of the body 11 depending on the drilling position and direction of the drain hole 37. In addition, in the drain hole 37 described above, the body 1
Since it is formed at a recessed position inside 1, there is also a problem that it is difficult to position the drill for drilling with respect to the front body 11. Further, since the hole drilling surface in the body 11 is inclined with respect to the drill tip, there is a problem that the drill tip slides and it is difficult to drill the hole.

The present invention has been made in view of the above circumstances, and a drain passage for collecting the leakage of the working fluid from the pump chamber, which is generated along the drive shaft, to the pump suction side is provided with an end surface of the pump body. Or, by forming a groove formed on the side surface of the side plate that is in contact with the side plate by casting or the like, positioning work or the like can be performed at the time of drilling, as compared with the conventional case where drilling is performed from an oblique direction. The purpose of the present invention is to obtain a vane pump that is unnecessary and can reduce the number of steps, improves workability, and can reduce costs.

[0016]

In order to meet such demands, a vane pump according to the present invention has a pump component having a rotor having a vane, a cam ring, and a side plate, and a working fluid housed in the pump chamber. A pump body having a pump suction side passage on the side of the side plate, and a drive shaft that is rotatably driven by the pump body and a shaft hole of the side plate to rotate the rotor. The drain passage for returning the leaked fluid, which has propagated from the pump chamber around the drive shaft from the pump chamber to the space on the inner end side of the seal member, to the pump suction side passage, the inner surface facing the body storage space, and the side plate in contact with this The groove is formed on at least one of the side surfaces of the.

In the vane pump according to the present invention, does the concave groove serving as a drain passage connect the opening end of the pump suction side passage opening to the inner surface facing the body storage space and the opening end of the shaft hole? , Or by molding by casting to connect between the body side end of the pump suction side passage groove on the side of the side plate contacting the inner surface facing the body storage space and the body side end of the shaft hole through which the drive shaft passes. Is forming.

[0018]

According to the present invention, the working fluid on the pump discharge side from the pump chamber formed by the pump components is pumped on the pump discharge side formed in the storage space of the pump body through the pump discharge side passage of the pressure plate. While flowing into the pressure chamber, a part of the pressure chamber is returned to the pump suction side through the flow control valve, while the remaining pressure oil passes through the clearance passage between the inner wall of the storage space and the outer peripheral side of the pressure plate. Is discharged from a discharge port having a metering orifice.

Leakage fluid from the pump chamber through the gap between the rotor and the side plates on both sides of the rotor, the pressure plate, and further through the drive shaft to the shaft hole of the side plate and the shaft hole of the pump body is leaked from the seal member. Is also accumulated in the space on the inner end side, and by a drain passage formed by a groove formed on the surface of the pump body in contact with the side plate or on the side surface of the side plate,
It is connected to the pump suction side passage in the pump body and is recirculated.

[0020]

1 (a), 1 (b) and 2 (c) show an embodiment of a vane pump according to the present invention. In these figures, the same or corresponding portions as those in FIG. Are assigned the same numbers and explanations thereof are omitted.

According to the present invention, in the vane pump 10 having the above-described structure, the side plate 20 of the front body 11 constituting the pump body with which the side plate 20 arranged in pressure contact with one side of the cam ring 17 contacts.
1 and 2 (a), (b),
As shown in (c), it is characterized in that the concave groove 40 serving as a drain passage for returning the leaked oil to the pump suction side is formed by molding with the body 11 by casting. That is, the oil leaked from the pump chamber 18 is located inside the shaft hole 11a of the front body 11 inside the portion where the oil seal 35, which is a sealing member, is interposed between the drive shaft 16 and the outer peripheral portion of the drive shaft 16. A space 36 is formed so as to be transmitted around the periphery of the space. The groove 40 connects between the space 36 and the pump suction side passage 27, and recirculates the leaked oil accumulated in the space 36 to the pump suction side.

In other words, the concave groove 4 which serves as the drain passage.
0 is the inner surface 41 of the front body 11 and the rear body 12
It is formed so as to connect between the opening end of the pump suction side passage 27 that opens so as to face the side storage space 14 and the opening end of the shaft hole 11a. When such a recessed groove 40 is formed in the front body 11 by casting, it can be formed when the body is molded, so that the drain passage can be formed easily and surely as compared with the conventional drill hole drilling process in another process. The number can be reduced, the workability can be improved accordingly, and the manufacturing cost can be reduced.

According to this structure, due to the existence of the drain passage formed by the concave groove 40 formed in the end surface of the front body 11, the drive shaft 16 is passed from the pump chamber 18 through the space between the rotor 15 and the side plates 20, 21. Leakage oil that reaches the portion and flows along the drive shaft 16 and collects in the space 36 on the inner end side of the oil seal 35 in the shaft hole 11 a of the front body 11 is formed in the groove 40.
It is possible to circulate back to the pump suction side passage 27 by the drain passage.

The pump chamber 1 accumulated in such a space 36
Since the oil leaking from 8 has a higher pressure than the pump suction side passage 27, the pressure difference allows the oil to flow back to the pump suction side. In addition, the concave groove 40 serving as the drain passage in the present invention
Is provided on the upstream side of the leakage path of the pressure oil from the pump chamber 18 to the inner side of the oil seal 35. The entire space 36 closer to the inner end than the oil seal 35 has a predetermined pressure due to the leakage oil. Is maintained, and a pressure difference is created between the pump suction side and the pump suction side, so that leaked oil can be reliably returned to the suction side.

3 and 4 (a) and (b) show another embodiment of the vane pump 10 according to the present invention, which is the same as or corresponds to the above-mentioned FIG. 1 and FIG. 2 in these drawings. The same reference numerals are given to the portions to be described, and detailed description will be omitted. In this embodiment, the concave groove 50 serving as a drain passage for collecting the pressure oil leaking through the drive shaft 16 and leaking to the pump suction side is provided in the pump component 1
3 side plates 20 are provided. That is, the side plate 20 is arranged such that one side surface thereof is in contact with the inner surface 41 of the front body 11 which faces the storage space 14 in the rear body 12 forming the pump body. On the side surface of the side plate 20, the pump suction passage 2
The recesses 50 connect the ends of the shafts 9 and 29 and the end of the shaft hole 20a through which the drive shaft 16 penetrates.

Even with the drain passage formed by the groove 50, it is possible to collect the leaked oil transmitted through the drive shaft 16 to the suction side of the pump in a required state, and the conventional drill hole machining is not required. That is, the same effect as that of the above-described embodiment can be obtained in that it can be easily formed by molding by casting. Here, in FIG.
In the figure, reference numeral 52 is a recess formed in the side plate 20 to be a pump discharge side passage groove, and 53 is the cam ring 17.
Of the inner cam surface having a substantially elliptical shape, in which the rotor 1
5 are arranged, so that a pair of pump chambers 18 are provided on both sides.
Is formed.

The present invention is not limited to the structure of the embodiment described above, and the shape, structure, etc. of each part of the vane pump 10 can be freely modified or changed. In the above-described embodiment, the concave grooves 40 and 5 that serve as the drain passage that characterize the present invention.
Although the case where 0 is formed on the front body 11 and the side plate 20 by casting is described, it may be formed by cutting, for example. Of course, in this case, the number of steps is increased by one, but the processing is easier than the conventional drilling. Further, in this case, since the conventional component can be used as it is, it has versatility and can reduce the cost. In addition, in the above-described two embodiments, the case where the recessed grooves 40 and 50 serving as the drain passages are provided at two places is illustrated, but the present invention is not limited to this, and may be provided at one place or three or more places.

Further, the vane pump 10 having the above-mentioned structure is not limited to the structure of the above-mentioned embodiment, but may be applied to various devices and apparatuses other than the power steering device described in the above-mentioned embodiment. Not to mention good things.

[0029]

As described above, according to the present invention, a rotor having a vane, a cam ring, and a pump component having a side plate are housed in a housing space inside the pump body, and the pump body is provided on the side of the side plate in the pump body. In a vane pump having a pump suction side passage, the leakage fluid that propagates around the drive shaft from the pump chamber to the space on the inner end side of the seal member between the body shaft hole and the drive shaft outer peripheral portion is passed to the pump suction side passage. The drain passage for the return flow is formed by the concave groove provided on at least one of the inner surface facing the body storage space and the side surface of the side plate in contact with the body storage space. Produce the effect.

That is, according to the present invention, by simply making a groove on the surface of the body facing the storage space or the side surface of the side plate, the leak fluid flowing from the pump chamber around the drive shaft is returned to the pump suction side passage. The drain passage can be easily formed. Therefore,
It is not necessary to drill holes from an oblique direction in the body for forming the drain passage, which is required in the conventional pump, and it is possible to contribute to a reduction in the number of work steps and a reduction in manufacturing cost.

In particular, according to the present invention, the concave groove serving as the drain passage is connected between the opening end of the pump suction side passage opening on the inner surface facing the body housing space and the opening end of the shaft hole.
Alternatively, since it is formed by connecting between the body side end of the pump suction side passage groove on the side surface of the side plate contacting the inner surface facing the body storage space and the body side end of the shaft hole through which the drive shaft passes, It is possible to exert the above-mentioned effects.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a vane pump according to the present invention.

2A is a side view of a front body in which a concave groove that serves as a drain passage, which is an essential part of the present invention, is formed, FIG. 2B is a cross-sectional view taken along line bb of FIG. 2, and FIG. It is a cc line sectional view.

FIG. 3 is a sectional view showing another embodiment of the vane pump according to the present invention.

FIG. 4 (a) is a side view of a side plate in which a concave groove serving as a drain passage, which is an essential part of the present invention, is formed, and FIG. 4 (b) is a sectional view thereof.

FIG. 5 is a sectional view showing a conventional vane pump.

[Explanation of symbols]

10 ... Vane pump, 11 ... Front body (pump body), 11a ... Shaft hole, 12 ... Rear body (pump body), 13 ... Pump component, 14 ... Storage space, 15 ...
Rotor, 15a ... Vane, 16 ... Drive shaft, 1
6a, 16b ... Bearing, 17 ... Cam ring, 17a ... Cam surface, 18 ... Pump chamber, 19 ... Pump cartridge, 20
... side plate, 20a ... shaft hole, 21 ... pressure plate, 25 ... pump discharge side pressure chamber, 27 ... pump suction side passage, 28 ... suction port, 29 ... pump suction side opening (pump suction side passage groove), 30 ... Flow control valve, 31 ... Discharge port, 35 ... Oil seal (seal member), 36 ...
Space, 40, 50 ... Recessed groove (drain passage), 41 ... Body inner surface, 52 ... Pump discharge side passage groove.

Claims (3)

[Claims] 1. A pump component having a cam ring for accommodating a rotor having a vane to form a pump chamber, a pump having a side plate disposed on one side of the cam ring, and accommodating the pump component and operating in the pump chamber. A pump body having a pump suction side passage for supplying fluid on the side plate side, and a rotor rotatably supported through a bearing in a shaft hole provided on the side plate side of the pump body and penetrating the side plate. In a vane pump including a drive shaft for rotationally driving a drive shaft and a seal member interposed between an outer peripheral portion of the drive shaft in an axial hole of the pump body, the drive shaft in the axial hole of the pump body. The drive chamber from the pump chamber into a space formed on the inner end side of the seal member with the outer peripheral portion of the A drain passage for recirculating leaked fluid traveling around the shaft to the pump suction side passage of the pump body on at least one of the inner surface of the pump body facing the storage space for pump components and the side surface of the side plate in contact therewith. A vane pump characterized by being formed by a provided groove. 2. The vane pump according to claim 1, wherein an opening end of the pump suction side passage and an opening end of the shaft hole are formed on the inner surface facing the storage space for the pump constituent elements of the pump body, the concave groove serving as the drain passage. A vane pump, characterized in that it is formed so as to be connected to and. 3. The vane pump according to claim 1, wherein an end of the side plate on the pump body side of the pump suction side passage groove is in contact with the inner surface of the pump body facing the storage space for the pump component of the pump body. A vane pump, characterized in that it is formed so as to connect between a pump body and an end portion on the pump body side of a shaft hole through which the drive shaft passes.