JPH10281081A - Gear pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing structure capable of pressing a partition plate stably over both entire side surfaces of a drive side gear and a driven side gear in a gear pump which is provided with the partition plate pressed against the both entire side surfaces of the drive side and driven side gears and so structured that it guides a part of the high pressure fluid at the delivery side to the rear surface side of the partition plate. SOLUTION: A gear pump is provided with a closed loop first sealing part 11a which is entered into the recessed part in the end surface of a cover part and encloses a delivery part and a suction part and a closed loop second sealing part 11b which is entered into the recessed part in the end surface of the cover part and encloses the suction part and partitions a delivery part from a suction part inside the first sealing part 11a. In this case, the cross sectional shape of the first and second sealing parts 11a and 11b are formed taperingly so that it becomes smaller in width at the end surface of a case than that at the bottom of the recessed part in the cover part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a circumscribing type gear pump having a driving gear that is driven to rotate, and a driven gear that is driven to rotate together with the driving gear.

[0002]

2. Description of the Related Art In a gear pump as described above, a case supporting a driving side gear and a driven side gear has a discharge section facing an occlusal start portion of the drive side gear and a driven side gear, and a suction section facing an occlusal end section. And is configured to send out the fluid sucked into the suction section to the discharge section along the inner peripheral surface of the case.

[0003] In this case, a partition plate is provided over both side surfaces of the drive side gear and the driven side gear to partition between gear teeth of the drive side gear and the driven side gear. In some cases, a part of the fluid is guided to the rear side of the partition plate, and the partition plate is pressed against both side surfaces of the drive gear and the driven gear. Thus, leakage of fluid from between the gear teeth of the driving side gear and the driven side gear is reduced, and a reduction in the volumetric efficiency of the gear pump is prevented.

[0004]

As described above, there is provided a partition plate applied to both side surfaces of the drive side gear and the driven side gear, and a part of the high-pressure fluid of the discharge portion is provided on the back surface of the partition plate. If it is configured to be guided to the side, a seal portion that separates the high-pressure discharge portion side and the low-pressure suction portion side from the back side of the partition plate is required. In the gear pump as described above, in the case where the high pressure discharge portion side and the low pressure suction portion side are partitioned by the seal portion, the partition plate is stably spread over both side surfaces of the drive side gear and the driven side gear. It is an object of the present invention to provide a configuration in which the seal portion has high durability so that the seal portion can be pressed.

[0005]

[Means for Solving the Problems]

[I] According to the feature of the first aspect, when the drive side gear and the driven side gear are driven to rotate, the fluid that has entered the suction portion is moved by the gear teeth of the drive side gear and the driven side gear to the inner peripheral surface of the case. , And is sent to the discharge section as a high-pressure fluid. Along with this, a part of the high-pressure fluid of the discharge section enters into the concave portion (between the first and second seal sections) of the lid section and enters the back side of the partition plate. The partition plate presses the partition plate against both side surfaces of the driving gear and the driven gear. In this case, the area on the discharge section side and the area on the suction section side in the recess of the lid section are the first section.
And the second seal portion, a part of the high-pressure fluid of the discharge portion enters the suction portion from the concave portion of the lid portion, and the force for pressing the partition plate against the side surfaces of the drive side gear and the driven side gear. There is no saying that it can be weakened.

As described above, when a part of the high-pressure fluid in the discharge portion enters the region on the discharge portion side (between the first and second seal portions on the suction portion side) in the concave portion of the lid portion,
One side and the other side of the region on the discharge section side are connected via the space between the first and second seal sections on the suction section side. As a result, the high-pressure fluid that has entered the region on the discharge unit side in the concave portion of the lid circulates between the first and second seal units on the suction unit side, and the pressure (partition plate) The force of pressing against the side surfaces of the drive side gear and the driven side gear) is suppressed from becoming uneven, and the partition plate is uniformly pressed on both the side surfaces of the drive side gear and the driven side gear without bias. You. As described above, if the pressure distribution in each section becomes uniform, the first seal section and the second seal section do not move or break due to the uneven pressure distribution.

When the lid is attached to the case and tightened with the first and second seals placed in the recesses of the lid,
If there is a slightly shallow portion due to a mechanical processing error in the concave portion of the lid portion, when the first and second seal portions are compressed by the bottom portion of the concave portion of the lid portion and the end surface of the case, the first and second seal portions have a small depth. The first and second seal portions expand laterally along the end surface of the case, and the expanded portions of the first and second seal portions attempt to enter between the end surface of the case and the corners of the concave portion of the lid portion. Sometimes. When this happens,
The first and second seals may be damaged and damaged by the corners of the concave portion of the lid. Further, in the first and second seal portions that are to enter between the end surface of the case and the corner of the concave portion of the lid, the contact area between the first and second seal portions and the end surface of the case is the first. And the contact area of the other portion of the second seal portion is greatly different from that of the first seal portion, and the surface pressure of each portion of the first and second seal portions is not uniform, which may result in leakage of fluid.

According to the first aspect of the present invention, the cross-sectional shape of the first and second seal portions is tapered so that the width on the end face side of the case is smaller than the width on the bottom side of the concave portion of the lid. I have. Thereby, in the slightly shallow portion of the concave portion of the lid portion,
When the first and second seal portions are compressed by the bottom of the concave portion of the lid portion and the end face of the case, even if the first and second seal portions expand laterally along the end face of the case in this shallow portion. Since the narrow sides of the first and second seal portions are expanded, the expanded portions of the first and second seal portions enter between the end surface of the case and the corners of the concave portion of the lid portion. It doesn't have to be like that. As a result, the state where the inflated portions of the first and second seal portions are pressed against the corners of the concave portion of the lid does not occur, and the first and second seal portions do not contact with the end surface of the case. There is no situation where the area is significantly different from the contact area of the other parts of the first and second seal portions.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 3, 4, and 5, a gear pump has an outer shape formed by a case 1 and a lid 2. A drive-side gear 3 and a driven-side gear 4 that are rotationally driven by a power source such as an engine (not shown) are provided. One of the shaft portions 3a and 4a of the drive-side gear 3 and the driven-side gear 4 is
The case 1 is rotatably supported via the bush 5,
The driving gear 3 and the driven gear 4 are in mesh.

As shown in FIGS. 3, 4, 5, and 6, the discharge portion 6 facing the engagement start portion of the driving gear 3 and the driven gear 4,
A discharge port 7 orthogonal to the discharge part 6 is formed in the case 1, and a suction part 8 facing the end of the engagement of the driving gear 3 and the driven gear 4 is formed in the case 1. FIG.
As shown in FIG. 6, a pair of horizontally long grooves 1a for collecting fluid leaking near the shafts 3a and 4a are formed in the case 1, and a recess 1b connecting the pair of grooves 1a and the suction portion 8 is formed. Are formed in the case 1.

[0011] As shown in FIGS.
A concave portion 2a facing the discharge portion 6 of the case 1 is formed in the lid portion 2 that opens one side surface of the driven gear 4, and a pipe-shaped suction port 9 is inserted into the lid portion 2 to perform suction. Port 9 is brazed (or welded) to lid 2. As shown in FIGS. 4, 5, and 6, the other shaft portions 3 b and 4 b of the drive-side gear 3 and the driven-side gear 4 are rotatably supported by the lid 2 via a bush 5.

As shown in FIGS. 5 and 6, on the end face of the lid 2 on the case 1 side, a closed loop-shaped first groove surrounding the outside of the concave portion 2a (discharge portion 6) and the suction port 9 (suction portion 8). 2b, a closed-loop second groove portion 2c surrounding the suction port 9 (suction portion 8) and the shaft portions 3b, 4b and communicating with the concave portion 2a (discharge portion 6) is formed inside the first groove portion 2b.
The first and second groove portions 2b,
2c is connected. Inside the second groove 2c, there is formed a third groove 2d for communicating the recesses of the shafts 3b, 4b and the suction port 9 (suction part 8).

The first convex portion 2e, the first and second groove portions 2b, 2 located between the first groove portion 2b and the concave portion 2a (ejection portion 6).
c, a pair of second convex portions 2f, a third convex portion 2g located between the second groove portion 2c and the concave portion 2a (ejection portion 6),
A fourth convex portion 2h located between the second groove portion 2c and the suction port 9 (the suction portion 8) and a fifth convex portion 2i located between the second and third groove portions 2c and 2d are formed.

As shown in FIGS. 1, 2, 5, and 6, the drive gear 3 and the driven gear 4 are attached to both sides of the drive gear 3 and the driven gear 4 on the lid 2 side. Is provided with a partition plate 10 for separating between the gear teeth. A pair of holes 10a of the shaft portions 3b, 4b of the driving side gear 3 and the driven side gear 4, a first concave portion 10c for keeping the discharge portion 6 (discharge port 7) of the case 1 from closing, and a suction portion 8 of the case 1 (Suction port 9) to prevent closing, a second recess 10d, a pair of notches 10e formed at a position close to the suction portion 8 (suction port 9) of the case 1, a driving gear 3 and a driven gear. Opening 10 located at the end of occlusion 4
g is formed on the partition plate 10.

As shown in FIGS. 1, 2, 5, 6, and 7, a sealing member 11 is provided in first and second grooves 2b and 2c on the end face of the lid 2, and the sealing member 11 is in a closed loop shape. First seal portion 11a, closed loop-shaped second seal portion 11
b, first and second ports on the suction port 9 (suction unit 8) side
A connecting portion 11c for connecting the sealing portions 11a and 11b,
And a groove 11d formed by the second seal portions 11a and 11b and the connection portion 11c.

As shown in FIGS. 7 and 8, the first seal portion 11 a at the concave portion 2 a (discharge portion 6) side (first
The first seal portion 11a that enters the groove portion 2b) and the second seal portion 11b side (the side opposite to the connection portion 11c in the thickness direction (vertical direction on the paper surface)) are formed on the inclined surface 11e.
The first seal portion 11a is tapered in cross section. In the portion of the second seal portion 11b on the side of the shaft portions 3b and 4b (the second seal portion 11 that enters the second groove portion 2c).
b), the first seal portion 11a side and the shaft portions 3b, 4b side (the side opposite to the connection portion 11c in the thickness direction (vertical direction on the paper surface)) are formed on the inclined surfaces 11f, 11g, and the second section in the cross section. The seal portion 11b is formed in a tapered shape.

As shown in FIGS. 7 and 9, first and second
In the portion of the seal portions 11a and 11b on the connection portion 11c side, the connection portion 11c side is formed on the inclined surface 11h,
In the cross section, the first and second seal portions 11a, 11a are tapered. As shown in FIGS. 1 and 7, at both ends of the connecting portion 11c, a convex portion 11i is formed integrally with the second sealing portion 11b and the connecting portion 11c so as to enter the connecting portion 11c. This convex part 11i
May be integrally formed over the first seal portion 11a and the connection portion 11c.

In the seal member 11 as described above, as shown in FIGS.
Into the first groove portion 2b, and the first seal portion 11a surrounds the outside of the concave portion 2a (discharge portion 6) and the suction port 9 (suction portion 8). The second seal portion 11b is connected to the second groove 2c.
Into the suction port 9 (suction section 8) and the shaft section 3
b, 4b, the first and second seal portions 11a, 11b
Thereby, the concave portion 2a (discharge portion 6), the suction port 9 (suction portion 8), and the shaft portions 3b, 4b are partitioned. In this case, as shown in FIGS. 9 and 3, the connecting portion 11c is located on the bottom side of the first and second grooves 2b and 2c of the lid portion 2, and as shown in FIGS. The inclined surfaces 11e, 11f, 11g and 11h of the second seal portions 11a and 11b are
0 and the case 1 side. This allows
One side and the other side of the concave portion 2a (ejection portion 6) are connected by the groove portion 11d.

With the above structure, in the gear pump, the driving gear 3 is rotated clockwise in FIG. 6 and the driven gear 4 is rotated counterclockwise in FIG. Thereby, as shown in FIGS.
The fluid that has entered the suction portion 8 of the case 1 from the suction port 9 of the case 1 is carried along the inner peripheral surface of the case 1 by the gear teeth of the drive side gear 3 and the driven side gear 4, and from the left and right sides of the paper of FIG. The liquid is sent to the discharge section 6 of the case 1 and is discharged as a high-pressure fluid from the discharge port 7.

Along with this, as shown in FIGS. 1, 2, 5 and 6, a part of the high-pressure fluid of the discharge part 6 is partially removed by the second seal part 11b of the seal member 11 and the first convex part 2e of the lid 2. And the first and second seal portions 11 of the seal member 11
From between a and 11b, both the second convex portions 2f of the lid 2 are reached. As described above, when a part of the high-pressure fluid reaches both the second convex portions 2f of the lid portion 2 from the discharge portion 6, the pressure decreases on the way. In this case, due to the gear teeth of the driving side gear 3 and the driven side gear 4, a part of the high-pressure fluid sent from the suction portion 8 along the inner peripheral surface of the case 1 is partially separated.
Into the lid 2 side through the notches 10e on both sides of the second projection 2f, and as described above, both the second convex portions 2f of the discharge unit 6 to the lid 2
To join the high pressure fluid that reaches.

As a result, the pressure is recovered, and while the high-pressure fluid whose pressure has been recovered is squeezed to some extent by the convex portion 11i, the groove portion 11d of the seal member 11 (the first and second seal portions of the seal member 11). 11a, 11b, a connecting portion 11c, and an elongated space surrounded by the case 1). As described above, the high-pressure fluid that reaches both the second protrusions 2f of the cover 2 from between the second seal portion 11b of the seal member 11 and the first protrusion 2e of the cover 2 in FIG. The partition plate 10 is hung on the outer peripheral portion on the back side of the partition plate 10 (excluding the outer peripheral portion near the second concave portion 10 d of the suction portion 8), and the partition plate 10 is pressed against the side surfaces of the driving gear 3 and the driven gear 4.

As described above, when the gear teeth meshing with the driving gear 3 and the driven gear 4 reach the suction section 8, the gear teeth of the driving gear 3 and the driven gear 4 are opened, and this opening is performed. Negative pressure is generated in the area where the pressure drops. In this case, as shown in FIGS. 1 and 2, when the gear teeth of the drive side gear 3 and the driven side gear 4 start to be opened on the suction section 8 side, the fluid of the suction section 8 flows through the opening 10 g of the partition plate 10 as described above. Of the gear teeth which have begun to open, and the generation of negative pressure is suppressed. As shown in FIGS. 4 and 6, fluid leaking to the vicinity of the shafts 3 a and 4 a on the case 1 side of the drive-side gear 3 and the driven-side gear 4 passes through the pair of grooves 1 a and the recess 1 b of the case 1. It is sent to the suction section 8.

[First Embodiment of the Invention] FIGS. 3 and 5
In this embodiment, the discharge port 7 and the suction port 9 are configured to be orthogonal to each other. However, as shown in FIG. 10, the pipe-shaped suction port 9 is formed so that the discharge port 7 and the suction port 9 are aligned. 1 and the suction port 9
May be brazed (or welded).

[Second Alternative Embodiment of the Invention] FIGS.
0, an intermediate case 12 is disposed between the case 1 and the lid 2 as shown in FIG. 11, and a drive-side gear 3 and a driven-side gear 4 disposed in the case 1 are separately provided. The driving gear 3 and the driven gear 4 may be connected to each other, and another driving gear 3 and the driven gear 4 may be arranged in the intermediate case 12. In this case, case 1 and intermediate case 1
2 and between the intermediate case 12 and the lid 2,
A partition plate 10 and a seal member 11 as shown in FIGS. 1 and 2 are arranged, and a pair of pipe-shaped suction ports 9 are aligned with the pair of discharge ports 7 of the case 1 and the intermediate case 12 so as to be aligned. Then, the pair of suction ports 9 are brazed (or welded) to the case 1 and the intermediate case 12. In the configuration shown in FIG.
An inclined surface 11e may also be formed on the right side of the seal portion 11a on the paper surface, and the cross section of the first seal portion 11a may be configured to be the same cross section as the second seal portion 11b.

[0025]

According to the first aspect of the present invention, in a gear pump provided with a partition plate applied to both side surfaces of the drive side gear and the driven side gear, a part of the high pressure fluid at the discharge portion is separated. And a part of the high-pressure fluid of the discharge part is pressed uniformly by the first and second seal parts against the side surfaces of both the driving gear and the driven gear evenly. By doing so, leakage of fluid from between the gear teeth of the driving gear and the driven gear was reduced, and the performance of the gear pump could be improved.

The first and second seal portions are formed in a tapered shape in which the width at the end face side of the case is smaller than the width at the bottom portion side of the concave portion of the lid portion. When the cover is attached to the case and tightened while the seal is placed in the recess of the cover, the first and second seals expand, and the space between the end face of the case and the corner of the recess of the cover is removed. It was possible to prevent such a situation as to enter. As a result, the durability of the first and second seal portions can be improved by preventing breakage of the first and second seal portions, and the surface pressure of each portion of the first and second seal portions can be maintained uniform to prevent fluid leakage. Could be prevented.

[Brief description of the drawings]

FIG. 1 is a front view of an end surface of a case with a partition plate and a seal member attached to the case side.

FIG. 2 is a perspective view of the vicinity of an end surface of the case in a state where a partition plate and a seal member are attached to the case side.

FIG. 3 is a longitudinal sectional side view of a gear pump.

FIG. 4 is a cross-sectional plan view of the gear pump.

FIG. 5 is an exploded perspective view of the entire gear pump.

FIG. 6 is an exploded front view of the entire gear pump.

FIG. 7 is a front view of the entire sealing member.

FIG. 8 is a cross-sectional view as viewed from the direction of the arrows in FIG. 7;

FIG. 9 is a cross-sectional view as viewed from a rolling direction in FIG. 7;

FIG. 10 is a longitudinal sectional side view of a gear pump according to a first alternative embodiment of the present invention.

FIG. 11 is a longitudinal sectional side view of a gear pump according to a second alternative embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Cover part 2b, 2c Concave part of the end surface of a cover part 3 Drive side gear 4 Follower side gear 6 Discharge part 8 Suction part 10 Partition plate 11a 1st seal part 11b 2nd seal part

Claims (1)

[Claims] A drive-side gear that is driven to rotate and a driven-side gear that meshes with the drive-side gear and that are driven to rotate together are supported by a case, and the driving-side gear and the driven-side gear are provided at an engagement start portion. The case includes: a discharge section facing the intake port; and a suction section facing the bite end portion of the drive gear and the driven gear.
A gear pump configured to send a fluid sucked into the suction portion to the discharge portion along an inner peripheral surface of the case, wherein a lid portion that opens one side surface of the drive side gear and the driven side gear. A partition plate attached to both sides of the drive side gear and the driven side gear on the lid side to partition between gear teeth of the drive side gear and the driven side gear; A concave portion communicating with the rear surface of the partition plate is formed in an end surface of the lid portion, and a first closed portion having a closed loop shape that enters the concave portion of the end surface of the lid portion and surrounds the discharge portion and the suction portion; A closed loop-shaped second seal portion that enters the concave portion of the end surface of the lid portion and surrounds the suction portion inside the first seal portion and separates the discharge portion and the suction portion; and the first and second seal portions. The cross-sectional shape of Gear pump than the width at the bottom side of the recess of the Kifuta portion is formed in a tapered shape whose width is narrowed at the end face side of the case.