CN100335793C - Oil hydraulic pump - Google Patents

Abstract

The present invention provides an oil pressure pump capable of preventing oil leakage due to damage of a sealing member even if oil leakage increases while continuously ensuring lubricity between a bush and a drive shaft. It has: a pump casing (3) formed with a through hole (3a); a pump element (1) housed between the pump casing (3) and the pump cover (2); The drive shaft (15) in the through hole (3a); the sealing chamber (11) and sealing member (12) arranged at the end of the through hole (3a); the drive shaft (15) and the bushing (13, 14) ) and the first oil groove (Y1) communicating from the pump element side of the through hole (3a) to the seal chamber (11); The second oil tank (Y2) that the sealed chamber (11) communicates with; the communication channel (19) that communicates from the sealed chamber (11) to the low pressure side (low pressure chamber 3c) of the pump element (1).

Description

Hydraulic pump

technical field

The invention relates to an oil pressure pump suitable for a power source such as a power steering device of a motor vehicle.

Background technique

In the prior art, this type of hydraulic pump is composed of a pump element housed between a pump casing and a pump cover, and a drive shaft is supported and arranged in a through hole passing through the aforementioned pump casing via a bush.

In addition, the above-mentioned hydraulic pump generally uses leakage oil leaked into the through hole accompanying the operation of the pump element as lubricating oil for the drive shaft.

Therefore, a helical oil groove is formed on the inner surface of the bush, and the leaked oil is introduced into the sealed chamber by passing through the oil groove to improve the lubricity between the bush and the drive shaft. This hydraulic pump The technique is well known (see Patent Document 1).

In addition, a technique of forming an oil groove between the bush and the through hole to achieve the same effect is also known (refer to Patent Document 2).

Patent Document 1

Japanese Publication No. 63-143786 (page 1-3, Figure 1)

Patent Document 2

Japanese Patent Application Laid-Open No. 11-13670 (pages 1-3, Figure 1)

However, in the invention of the above-mentioned Patent Document 1, when the above-mentioned oil leakage increases, the flow velocity of the leakage oil flowing through the above-mentioned oil groove will increase, and the stress will exceed the sealing ability of the sealing member, resulting in damage to the sealing member. There is a problem that leaked oil may leak from between the seal member and the drive shaft to the outside of the pump casing.

In addition, when the flow rate of leaked oil flowing through the oil groove increases, the load on the bush also increases, thereby reducing the durability of the bush.

In addition, the opening end portion of the oil groove on the seal chamber side faces the lip portion of the seal member, and has a structure that easily receives stress due to the flow rate of leakage oil.

In addition, in the invention of Patent Document 2, since leaked oil cannot sufficiently penetrate between the bush and the drive shaft, there is a problem that the required lubricity cannot be obtained for the drive shaft.

Contents of the invention

The present invention has been made in view of the above problems, and its object is to provide an oil hydraulic pump that can ensure lubricity between the bush and the drive shaft and that can also reduce oil leakage when oil leakage increases. This prevents damage to the seal and leakage to the outside.

The first aspect of the present invention is a hydraulic pump, characterized by comprising: a pump casing formed with a through hole; a pump cover combined with the pump casing; a pump element accommodated between the pump casing and the pump cover; A bush provided in the through hole; a drive shaft supported in the bush; a seal chamber provided at the end of the through hole; a seal member provided in the seal chamber, the seal member connecting the pump casing and the drive shaft Partition seal between them; the first oil groove is arranged between the aforementioned drive shaft and the bushing, and communicates with the seal chamber from the pump element side of the aforementioned through hole, and introduces the seal oil leaked from the pump element into the through hole into the seal chamber The second oil tank communicates from the pump element side of the aforementioned pump bushing to the sealed chamber, and the leaked oil leaked from the pump element into the through hole avoids the aforementioned first oil groove and introduces it into the sealed chamber; the first communication channel communicates from the aforementioned The sealed chamber communicates with the low-pressure side of the pump element, and oil leakage in the sealed chamber is recovered. The seal member has a lip provided on a sliding surface with the drive shaft, and the second oil groove is provided with an opening end of the second oil groove on the seal chamber side at a position radially shifted from the lip of the seal member. Location.

Therefore, in the hydraulic pump of the present invention, since the leaked oil leaked from the pump element side into the through hole flows into the first oil groove, it functions as lubricating oil between the drive shaft and the bushing, and as a result, the drive shaft is obtained. good lubricity.

In addition, since the leaked oil is branched into two channels, the first oil tank and the second oil tank, and introduced into the sealed chamber, even if the amount of the leaked oil increases, the second oil tank becomes a bypass passage for the first oil tank, and there is no need to It will be that all the leaked oil flows into the first oil tank.

Therefore, compared with the conventional invention, since the amount of leaked oil flowing into the first oil groove can be reduced and its flow velocity can be reduced, damage to the bush and seal member due to the stress of the leaked oil can be prevented.

According to the present invention, leakage oil introduced into the second oil tank can be prevented from directly colliding violently with the lip, unnecessary stress on the lip can be reduced, and the durability of the sealing member can be improved.

A second aspect of the present invention is the hydraulic pump described in the first aspect, wherein the bushing is composed of a first bushing on the seal chamber side and a second bushing on the pump element side separated by a predetermined distance in the axial direction, A space is formed between the first and second bushes, the drive shaft, and the through hole.

According to the second aspect of the present invention, since the space portion is formed between the first bush and the second bush, the space portion becomes an oil storage space, and the flow velocity of leaked oil flowing into the sealed chamber is slowed down.

The third aspect of the present invention is the hydraulic pump described in the second aspect, characterized in that the distance between the first bush and the second bush is not greater than the two ends of the first bush and the second bush 1/3 of the length along the axis between the parts.

According to the third aspect of the present invention, it is possible to secure a sufficient length of the bush to support the drive shaft.

The invention described in claim 4 of the present invention is the hydraulic pump described in claim 2, wherein the second oil tank communicates with the space portion and the sealed chamber.

According to the fifth aspect, leak oil whose flow velocity has been sufficiently reduced in the space portion serving as the oil storage space can be introduced into the sealed chamber.

The invention according to claim 5 of the present invention is the hydraulic pump according to claim 2, wherein the end portion of the first oil groove formed in the first bush on the side of the seal chamber faces the lip portion of the seal member. The pump element side end of the first oil groove is opened toward the space.

According to the fifth aspect, since the leaked oil whose flow velocity is sufficiently reduced in the space portion serving as the oil storage space can be introduced into the vicinity of the lip through the first oil groove, the load of the leaked oil on the lip can be reduced.

The invention described in claim 6 of the present invention is the hydraulic pump described in claim 2, further comprising a third oil groove communicating from the pump element side of the second bushing to the space portion so as to connect the pump element side of the second bush to the space. Oil leaked from the pump element into the through hole avoids the first oil groove of the second bush.

According to the sixth aspect, since all the leakage oil flowing into the pump element side of the second bushing does not flow into the first oil groove of the second bushing, when the oil leakage increases, the leakage into the sealing chamber can be reduced at an earlier stage. The flow rate of the oil can be more effective in preventing damage to the first and second bushings and sealing parts.

The invention described in claim 7 of the present invention is the hydraulic pump described in claim 6, characterized in that the opening on the space side of the second oil groove that communicates the space and the sealed chamber, and the opening that communicates the pump element and the space The openings on the side of the space portion of the third oil groove are provided at positions shifted by 180 degrees.

According to the seventh aspect, the flow resistance of leaked oil flowing into the second oil tank via the third oil tank can be greatly reduced, and as a result, the flow velocity of the leaked oil can be effectively reduced.

The invention described in claim 8 of the present invention is the hydraulic pump described in claim 2, further comprising a second communication passage directly connecting the space portion and the low-pressure side.

According to the eighth aspect, since the second communication passage reduces the flow rate of the leaked oil flowing into the first oil groove, even if the leaked oil increases, it is possible to prevent the lip from being damaged due to the stress caused by the increased flow rate of the leaked oil. The phenomenon.

The invention described in claim 9 of the present invention is the hydraulic pump described in claim 1, further comprising a second communication passage directly communicating from the pump element side to the low pressure side of the through hole.

According to the ninth aspect, the leakage oil flowing into the pump element side of the bush is branched into two flow paths, one of which is introduced into the seal chamber through the first oil groove, and the other directly flows into the low-pressure side of the pump element. All the oil will flow into the first oil groove of the bush. As a result, the amount of oil leaking into the first oil groove can be reduced, and damage to the bush and sealing parts can be prevented more effectively.

The invention described in claim 10 of the present invention is the hydraulic pump described in claim 1, characterized in that the second oil tank is arranged such that when the hydraulic pump is mounted on a vehicle, the second oil tank is located vertically below. side.

According to the tenth aspect of the invention, leaked oil tends to flow into the second oil tank due to its own weight, so that oil leaked to the first oil tank can be effectively reduced.

The invention described in claim 11 of the present invention is the hydraulic pump described in claim 1, wherein the bush is formed by bending a plate member in which the first oil groove is formed into a cylindrical shape.

According to the eleventh aspect, although it is very difficult to form the oil groove on the inner peripheral surface of the cylindrical member, since the bushing of the present application is formed by bending the plate member formed with the oil groove into a cylindrical shape, the processing is very easy. .

The invention described in claim 12 of the present invention is the hydraulic pump described in claim 1, wherein the first oil groove is formed on the inner peripheral surface of the bush.

According to the twelfth invention, since the first oil groove is formed on the side of the bush, it is not necessary to provide the oil groove on the drive shaft requiring high strength.

The invention described in claim 13 of the present invention is the hydraulic pump described in claim 1, wherein the second oil groove is located between the through hole and the bushing, and is located on the inner peripheral surface of the through hole. .

According to the thirteenth aspect, since the second oil groove is formed on the inner peripheral surface of the through hole, the second oil groove can be formed simultaneously with the through hole.

The invention described in claim 14 of the present invention is the hydraulic pump described in claim 1, wherein the first communication passage is provided in parallel to the through hole.

According to the fourteenth aspect of the invention, since the first communication passage is provided in parallel with the through hole, the layout is good, and the hydraulic pump can be miniaturized.

Description of drawings

Fig. 1 is a sectional view showing a hydraulic pump according to Embodiment 1 of the present invention.

Fig. 2 is a sectional view of S1-S1 in Fig. 1 .

FIG. 3 is a schematic diagram illustrating an oil leakage flow path of the present embodiment.

Fig. 4 is a developed view of the bushing of this embodiment.

FIG. 5 is a schematic diagram illustrating an oil leakage flow path of the present embodiment.

FIG. 6 is a schematic diagram illustrating an oil leakage flow path of the present embodiment.

Explanation of symbols: O1, O2 are space parts, P is the driving mechanism, R is the lip, S is the flow control valve, Y1, Y3 are the first oil tank, Y2 is the second oil tank, Y4 is the third oil tank, 1 is the pump element , 2 is the pump cover, 3 is the pump casing, 3a is the through hole, 3c is the low pressure chamber, 3d is the discharge channel, 3e, 3f are the channels, 4 is the cam ring, 5 is the impeller, 6 is the rotor, 6a is the spline hole (serration holes), 7 and 8 are side plates, 7a and 8a are notch-shaped passages, 9 is a pump chamber, 11 is a sealing chamber, 12 is a sealing member, 13 and 14 are bushings, 15 is a drive shaft, and 16 is a flower Key portions, 17 and 18 are sealing portions, 19 is a communication passage, 19a is a second communication passage, and 20 is a discharge chamber.

Detailed ways

Next, an embodiment of the hydraulic pump of the present invention will be described.

An example in which the hydraulic pump for a power steering device in this embodiment, specifically, a vane pump is applied will be described.

However, the hydraulic pump of the present invention is not limited to be applicable only to power steering devices, and is also applicable to all common liquid pumps in other forms such as plunger pumps and piston pumps.

<Example 1>

Next, Embodiment 1 of the present invention will be described.

Fig. 1 is a cross-sectional view of a hydraulic pump showing Embodiment 1 of the present invention, Fig. 2 is a cross-sectional view of S1-S1 in Fig. 1, Fig. 3 is a developed view of a bushing of this embodiment, and Fig. 4 is a diagram illustrating this embodiment A schematic diagram of the leakage oil flow path of the hydraulic pump.

As shown in Figures 1 and 2, the hydraulic pump of this embodiment is mainly composed of a pump cover 2, a pump casing 3 and a drive shaft 15, wherein the pump cover 2 is used to accommodate the pump element 1, and the pump casing 3 is formed There is a through hole 3a, and the drive shaft 15 is installed in the through hole 3a.

The cam ring 4 of the aforementioned pump element 1 is set in a state sandwiched between the side plates 7 and 8 described later, and the rotor 6 is housed in the cam ring 4 at the same time. 5 impellers.

In addition, a pump chamber 9 partitioned by adjacent impellers 5 is formed in the cam ring 4 .

The volume of the pump chamber 9 changes due to the rotation of the rotor 6 , the portion that increases due to the change in volume forms a suction area, and the portion where the volume decreases forms a discharge area.

The side plates 7 and 8 opposite to the discharge area are formed with notch-shaped passages 7a and 8a open in the radial direction to discharge the internal working oil into the discharge chamber 20 of the annular recess on the periphery of the cam ring 4 .

In addition, an unillustrated suction port is formed through the side plate 7 facing the aforementioned suction area.

A seal chamber 11 and a seal member 12 are provided at the end of the through hole 3a of the pump casing 3, and the drive shaft 15 is supported by a bush 13 (first bush) and a bush 14 (second bush) described later. inside the through hole 3a.

The drive shaft 15 is used to drive the pump element 1, and the spline portion 16 on the pump element 1 side passes through the through hole 7b of the side plate 7 and is inserted into the spline hole 6a of the rotor 6, whereby the drive shaft 15 drives the rotor 6 In rotation, in other words, the drive shaft 15 drives the pump element 1 .

In addition, the front end of the drive shaft 15 on the pump element 1 side is fitted into the through-hole 8 a of the side plate 8 with some play.

As shown in FIG. 3 , the bushes 13 , 14 are each formed in a cylindrical shape bent from a plate member having two grooves M formed thereon so that the grooves M are on the inner side.

In addition, the bushes 13 and 14 are provided at predetermined intervals in the axial direction of the drive shaft 15 .

In addition, the aforementioned predetermined interval is a distance required to receive the drive shaft 15 , and is, for example, approximately 1/3 of the distance between the two ends of the bushes 13 and 14 .

Also, the opening end of the first oil groove Y1 formed on the inner surface of the bush 13 on the side of the seal chamber 11 faces the seal member 12, specifically, the lip R of the seal member 12. 12 connected.

On the other hand, the opening end of the first oil groove Y1 on the side of the pump element 1 is connected to the space O1 sandwiched between the bushes 13 and 14 .

In addition, the second oil groove Y2 communicating from the space portion O1 to the sealed chamber 11 is formed so as to avoid the first oil groove Y1.

The second oil groove Y2 is formed at the lowermost portion of the through hole 3a in the axial direction, and is separated from the first oil groove Y1 by a bush 14 (see FIG. 2 ).

In addition, the opening end of the second oil groove Y2 on the side of the sealing chamber 11 is displaced radially outward with respect to the lip R so that oil leakage described later does not directly hit the lip R strongly.

On the other hand, like the bush 13, the bush 14 is also formed with a first oil groove Y3 that communicates the space O2 on the pump element 1 side with the space O1.

Furthermore, the pump housing 3 is provided with the pump chamber 9 communicating with the suction area and the low-pressure chamber 3c (low pressure side of the pump element) of the oil storage tank outside the figure, and the pump chamber 9 communicating with the discharge area and the power steering device outside the figure. The discharge passage 3d of the hydraulic actuator (actuator), the flow control valve S, etc., the flow control valve S discharges the remaining hydraulic oil in the discharge chamber 20 from a discharge port (not shown) to control the flow rate.

The low-pressure chamber 3c is formed by branching in two directions along the axial direction at the joint with the side plate 7, and an arc-shaped suction port (not shown) is formed at the front end thereof.

In addition, an unillustrated suction port is formed in the side plate 7, and the aforementioned low-pressure chamber 3c is formed facing the suction port.

In addition, the low-pressure chamber 3c is connected to the sealed chamber 11 through a passage 19 formed substantially parallel to the through-hole 3a.

In addition, the pump casing 3 and the pump cover 2 are connected and fixed to each other by unshown bolts, etc. In addition, the joint between the two is used to prevent the leakage of oil discharged into the discharge chamber 20 from leaking to the outside by the sealing part 17. The state of the leak.

In addition, a sealing portion 18 is provided between the pump cover 2 and the side plate 8 so that the discharge chamber 20 and the through hole 3 a are sealed off.

In addition, a driving mechanism P such as a driving wheel is attached to an end portion of the driving shaft 15 protruding from the pump housing 3, and the driving wheel is driven to rotate by an internal combustion engine (not shown).

Next, the operation of the hydraulic pump of this embodiment will be described.

In the hydraulic pump with such a structure, the drive mechanism P drives the drive shaft 15 to rotate to drive the rotor 6 to rotate.

And, by the rotation of the aforementioned rotor 6, the working oil is supplied from the passage 3e to the low-pressure chamber 3c, and then sucked into the pump chamber 9 in the suction area.

Here, the working oil is pumped and discharged from the pump chamber 9 in the discharge area into the discharge chamber 20 .

Thereafter, the operating oil discharged into the discharge chamber 20 is discharged into the hydraulic transmission of the power steering device not shown in the figure through the passage 3f of the discharge passage 3d while the flow rate thereof is controlled by the flow control valve S.

Then, the aforementioned working oil is discharged from the channel 3f on the one hand and leaks from the pump element 1 into the space portion O2 along the drive shaft 15 mainly through the gap formed for the lubrication of the rotor 6 and the side plates 7 and 8 on the other hand.

The leaked oil leaked into the aforementioned space O2 acts as a lubricating oil in the space O2, and flows into the first oil groove Y3 of the bushing 14 to serve as a lubricating oil between the drive shaft 15 and the drive shaft 15. At the same time, it is introduced into the space part O1.

Thereafter, the leakage oil flowing from the space portion O1 into the first oil groove Y1 of the bush 13 is introduced into the seal chamber 11 while serving as lubricating oil between the drive shaft 15 and the drive shaft 15 .

On the other hand, the leakage oil flowing into the second oil groove Y2 from the space portion O1 avoids the first oil groove and is directly introduced into the sealing chamber 11 .

In addition, since the second oil groove Y2 is provided at the lowermost portion of the through hole 3a as described above, leaked oil can easily flow into the second oil groove Y2 by its own weight.

In addition, since the leakage oil in the second oil tank Y2 is not affected by the rotation of the drive shaft 15, it flows more smoothly than in the first oil tank Y1.

Next, the leakage oil flowing into the sealed chamber 11 returns to the low-pressure chamber 3c on the low-pressure side of the pump element 1 through the communication passage 19, and circulates in the pump element 1 again.

That is, as shown in FIG. 4 , in the hydraulic pump of this embodiment, the leaked oil leaked from the pump element 1 side into the space O2 passes through the first oil groove Y3 of the bushing 14 and enters the space O1, and then branches to pass through the space O1. The first oil groove Y1 of the bushing 13 is introduced into the flow path in the sealed chamber 11 (indicated by the solid line arrow in the figure) and the second oil groove Y2 is introduced into the flow path in the sealed chamber 11 (indicated by the dotted line arrow in the figure).

In addition, in FIG. 4, the 2nd oil groove Y2 is shown as being located in the side position of the drive shaft 15 for convenience of description.

Therefore, for the hydraulic pump of this embodiment, the first oil grooves Y1, Y3 can obtain the required lubricity between the drive shaft 15 and the bushes 13, 14 (corresponding to the first aspect of the present invention).

In addition, since the second oil tank Y2 functions as a bypass passage for the first oil tank Y1, not all of the leaked oil flows into the first oil tank Y1. In the case of the leaked oil, it is also possible to reduce the amount of leaked oil flowing into the first oil groove Y1, reduce the flow rate of the leaked oil, and prevent damage to the bushing 13 and the sealing member 12 caused by the stress of the leaked oil (similar to the first oil leak of the present invention). Corresponding aspects).

In addition, since the opening end of the second oil groove Y2 on the side of the sealing chamber 11 communicates with the position radially shifted from the lip R of the sealing member 12, it is possible to prevent the leakage oil introduced into the second oil groove Y2 from directly colliding with the lip. The lip portion R can avoid excessive stress being applied to the lip portion R, thereby improving the durability of the sealing member 12 .

Also, since in this embodiment, the first oil groove Y1 is formed on the inner peripheral surface of the bushing 13, there is no need to form an oil groove on the drive shaft 15 which requires strength. At the same time, since the second oil groove Y2 is formed on the Therefore, the second oil groove Y2 and the through hole 3a can be formed at the same time.

<Example 2>

Next, Embodiment 2 of the present invention will be described.

In the hydraulic pump of this embodiment, except that the third oil groove Y4 communicating with the space O2 and the space O1 is formed avoiding the first oil groove Y3 of the bush 14, other parts are the same as those of the first embodiment. The same symbols are used for the same structural components, and therefore, their descriptions are omitted here.

FIG. 5 is a schematic diagram illustrating a flow path of oil leakage according to Example 2 of the present invention.

As shown in FIG. 5 , in the hydraulic pump of this embodiment, the third oil groove Y4 that communicates with the space O2 and the space O1 is formed while avoiding the first oil groove Y3 of the bush 14 .

In addition, in FIG. 5 , the second oil groove Y2 and the third oil groove Y4 are shown as being located on the side of the drive shaft 15 for convenience of description, but the second oil groove Y2 is formed at the lowest position of the through hole 3 a. , the third oil groove Y4 is formed at the uppermost position of the through hole 3a.

Next, the operation of the hydraulic pump of this embodiment will be described.

In addition, description of the operation of the pump element 1 is omitted since it is the same as that of the first embodiment described above.

In the hydraulic pump of the present embodiment, as in the first embodiment described above, leakage oil leaked from the pump element 1 flows into the space O2, and functions as lubricating oil in the space O2.

Then, the leakage oil flowing into the first oil groove Y3 of the bush 14 from the space portion O2 functions as lubricating oil between the drive shaft 15 and is introduced into the space portion O1.

On the other hand, the leakage oil flowing into the third oil groove Y4 from the space part O2 avoids the first oil groove Y3 and directly flows into the space part O1.

In addition, since the leakage oil in the third oil tank Y4 is not affected by the rotation of the drive shaft 15, it flows more smoothly than in the first oil tank Y3.

Next, the leakage oil flowing from the space portion O1 into the first oil groove Y1 of the bush 13 is introduced into the seal chamber 11 while functioning as lubricating oil for the drive shaft 15 .

On the other hand, the leakage oil flowing into the second oil groove Y2 from the space portion O1 avoids the first oil groove Y1 and directly flows into the sealing chamber 11 .

Next, the leakage oil flowing into the sealed chamber 11 returns to the low-pressure chamber 3 c through the communication passage 19 and circulates again in the pump element 1 .

That is, in the hydraulic pump of this embodiment, after the leakage oil leaked from the pump element 1 is collected in the space part O2, it is branched into a flow path introduced into the space part O1 through the first oil groove Y3 of the bushing 13 (as shown in FIG. Indicated by the solid line arrow) and the third oil tank Y4 into the flow path in the space O1 (as indicated by the dashed arrow in the figure).

Therefore, in the hydraulic pump of this embodiment, the first oil grooves Y1 and Y3 can provide the required lubricity between the bushes 13 and 14 and the drive shaft 15 (corresponding to the first aspect of the present invention).

In addition, even when the amount of leaked oil increases, not all of the leaked oil flowing into the space O2 flows into the first oil groove Y3 of the bushing 14. As a result, the flow velocity of the leaked oil can be reduced at an earlier stage, which is more effective. Damage to the bushings 13, 14 and the sealing member 12 is prevented to a minimum.

In addition, since the second oil groove Y2 is formed at the uppermost position of the through hole 3a, the third oil groove Y4 is formed at the lowermost position of the through hole 3a. Since the position rotated by 180 degrees in the circumferential direction can increase the flow resistance to the leaked oil passing through the third oil groove Y4 and flow into the second oil groove Y2, as a result, the flow velocity of the leaked oil can be effectively reduced.

<Example 3>

Hereinafter, Embodiment 3 of the present invention will be described.

First, the hydraulic pump of this embodiment is the same as that of the first embodiment except that the second oil groove Y2 is omitted and the second communication passage 19a connecting the space O2 and the low-pressure chamber 3c is formed. The same reference numerals are used for constituent parts, and descriptions thereof are omitted.

Fig. 6 is a schematic diagram illustrating an oil leakage flow path according to Embodiment 3 of the present invention.

As shown in FIG. 6, the hydraulic pump of this embodiment is formed with the 2nd communication passage 19a which communicates with the space part O2 and the low-pressure chamber 3c.

In addition, the aforementioned second communication passage 19 a is provided at the uppermost position of the through hole 3 .

In addition, it is preferable to provide a flow control valve capable of adjusting the leakage oil flow rate described later in the second communication passage 19a.

Next, the operation of the hydraulic pump of this embodiment will be described.

The description of the operation of the pump element 1 is omitted here because it is the same as that of the first embodiment described above.

In the hydraulic pump of this embodiment, as in the first embodiment described above, leaked oil leaked from the pump element 1 is collected in the space portion O2.

Next, the leaked oil functions as lubricating oil in the space O2, flows into the first oil groove Y3 of the bush 14 to function as lubricating oil for the drive shaft 15, and flows into the space O1.

Next, the leakage oil flowing into the first oil groove Y1 from the space portion O1 is introduced into the sealed chamber 11 while functioning as lubricating oil for the drive shaft 15 , and then introduced into the low-pressure chamber 3c through the communication passage 16 .

On the other hand, the leakage oil flowing into the second communication passage 19a from the space portion O1 is directly introduced into the low-pressure chamber 3c.

Then, the leakage oil flowing into the low-pressure chamber 3c from the second communication passage 19a and the first oil groove Y1 circulates again in the pump element 1 .

That is to say, in the hydraulic pump of this embodiment, the leakage oil leaked from the pump element 1 is collected in the space part O2, and after being introduced into the space part O1 through the first oil groove Y3 of the bushing 14, it is branched to pass through the first oil groove. Y1 is introduced into the flow path in the sealed chamber 11 (shown by the solid arrow in the figure) and into the flow path in the low-pressure chamber 3c (shown by the dotted arrow in the figure) through the second communication channel 19a.

Therefore, in the hydraulic pump of this embodiment, ideal lubricity between the bushes 13, 14 and the drive shaft 15 can be obtained by the first oil grooves Y1, Y3 (corresponding to the first aspect of the present invention).

In addition, since the second communication passage 19a reduces the flow rate of the leaked oil flowing through the first oil groove Y1, even if the leaked oil increases, it is possible to prevent the lip R from being damaged by its stress due to the increased flow velocity of the leaked oil. .

The embodiments of the present invention have been described above, but the specific configuration of the present invention is not limited to the embodiments, and modifications and designs made within the scope of the present invention are also included in the present invention.

For example, the shape, position, and formation quantity of each oil groove through which the leaked oil flows can be properly set.

In addition, valves may also be provided in each oil tank through which the leaked oil flows.

Claims (14)

1. oil pressure pump has:

Be formed with the pump case of through hole;

Pump cover with aforementioned pump case combination;

Receipts are loaded on the pump element between aforementioned pump case and the pump cover;

Be located at the lining in the aforementioned through hole;

Be supported in the live axle of said sleeve;

Be arranged at the closed chamber of aforementioned through hole end;

Be arranged at the sealed member in the aforementioned closed chamber, the sealing parts are with exclusion seal between aforementioned pump case and the live axle; It is characterized by, also have:

The 1st oil groove is arranged between aforementioned live axle and the lining, and is communicated with from the pump element lateral seal chamber of aforementioned through hole, will import closed chamber from the sealing oil that this pump element drains to the through hole;

The 2nd oil groove from the pump element lateral seal chamber connection of aforementioned pump bushing, will be avoided aforementioned the 1st oil groove and import closed chamber from the leakage of oil that this pump element drains to the through hole;

With the 1st communication passage, be communicated with from the low voltage side of aforementioned closed chamber to pump element, and the leakage of oil in the recovery sealing chamber;

Aforementioned sealed member has the lip that is arranged on the slip surface place of aforementioned live axle, and aforementioned the 2nd oil groove is arranged at the position that the lip with aforementioned sealed member staggers diametrically with the open end of the closed chamber side of the 2nd oil groove.

2. the oil pressure pump of putting down in writing as claim 1 is characterized by, and said sleeve is made of the 1st lining of the closed chamber side of spaced apart predetermined distance and the 2nd lining of pump element side vertically, forms space portion between the 1st, the 2nd lining and live axle and through hole.

3. the oil pressure pump of putting down in writing as claim 2 is characterized by, and the span between aforementioned the 1st lining and the 2nd lining is not more than 1/3 of length axially between the two end part of the 1st lining and the 2nd lining.

4. the oil pressure pump of putting down in writing as claim 2 is characterized by, and aforementioned the 2nd oil groove is communicated with aforesaid space portion and aforementioned closed chamber.

5. the oil pressure pump of putting down in writing as claim 2 is characterized by, and the end of aforementioned closed chamber side of the 1st oil groove that is formed at aforementioned the 1st lining is towards the lip opening of aforementioned sealed member, and the end of the pump element side of the 1st oil groove is towards aforesaid space portion opening.

6. the oil pressure pump of putting down in writing as claim 2 is characterized by, and also has the 3rd oil groove, and the 3rd oil groove is communicated with from the pump element side direction aforesaid space portion of aforementioned the 2nd lining, makes from this pump element and drains to the 1st oil groove that aforementioned the 2nd lining is avoided in leakage of oil the through hole.

7. the oil pressure pump of putting down in writing as claim 6, it is characterized by, be communicated with the opening portion of aforesaid space portion and the space portion side of the 2nd oil groove of closed chamber and be communicated with the opening portion of space portion side of the 3rd oil groove of aforementioned pump element and space portion, be arranged at 180 positions of spending of staggering.

8. the oil pressure pump of putting down in writing as claim 2 is characterized by, and also has the 2nd communication passage of direct connection aforesaid space portion and low voltage side.

9. the oil pressure pump of putting down in writing as claim 1 is characterized by, and also has the 2nd communication passage that directly is communicated with from the pump element side direction low voltage side of aforementioned through hole.

10. the oil pressure pump of putting down in writing as claim 1 is characterized by, and aforementioned the 2nd oil groove is arranged to, and under oil pressure pump was loaded onboard state, the 2nd oil groove was positioned at the Vertical direction downside.

11. the oil pressure pump as claim 1 is put down in writing is characterized by, said sleeve forms by the curved circle of the plate member that will be formed with aforementioned the 1st oil groove.

12. the oil pressure pump as claim 1 is put down in writing is characterized by, aforementioned the 1st oil groove is formed at the inner peripheral surface of said sleeve.

13. the oil pressure pump as claim 1 is put down in writing is characterized by, aforementioned the 2nd oil groove and is positioned at the inner peripheral surface of this through hole between aforementioned through hole and said sleeve.

14. the oil pressure pump as claim 1 is put down in writing is characterized by, aforementioned the 1st communication passage and aforementioned through hole are provided with abreast.

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