JP2001153066A - Gear pump - Google Patents

Abstract

(57) [Problem] To provide an oil film on a sliding surface between a side plate and a gear, to prevent abrasion, damage, galling, etc., and to ensure stable pump performance for a long period of time. . A pump assembly including a side plate, a pair of gears, a seal block, and the like is provided in a housing. Oil grooves 19 and 20 for lubrication are provided on the sliding surface of the side plate 5 with respect to the gear. One end of the oil grooves 19 and 20 communicates with the low-pressure chamber 13 through the relief groove 17 near the meshing portion of the gear, and the other end communicates with the annular grooves 21 and 22 around the shaft portions 8B and 9B. The oil grooves 19 and 20 extend obliquely from the position of the clearance groove 17 in the rotational direction of the gear, and form an inverted "C" shape as a whole and are tangentially connected to the annular grooves 21 and 22. I have. The oil grooves 19 and 20 are configured to extend in a direction intersecting the radial direction of the gear.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear pump suitably used as a hydraulic pressure source for, for example, a vehicle brake device.

[0002]

2. Description of the Related Art In general, gear pumps are used in various industrial fields as small and lightweight pumps because of their simple structure and high reliability. For example, they are also used as fuel injection pumps for vehicle engines. For example, JP-A-10-
252589).

[0003] A gear pump according to the prior art of this type includes a housing forming an outer shell, left and right side plates provided in the housing so as to face each other and forming a gear chamber between opposing surfaces, and the respective side plates. The two supporting shafts are rotatably supported by the side plates, and are provided in mesh with each other in a gear chamber between them.
And a low-pressure chamber formed between the side plates at a position on the low-pressure side with respect to the meshing portion of the gears and communicating with an inflow port in the housing; and a low-pressure chamber around each of the gears. And a high-pressure chamber communicating with a discharge port of the housing.

[0004] One of the two gears serves as a driving gear, and is driven by an external drive source via a support shaft to rotate while meshing with the other driven gear. Thereby, the oil liquid such as fuel guided from the inflow port is sent from the low-pressure chamber toward the high-pressure chamber,
It is discharged from the discharge port to the outside.

[0005]

The gear pump according to the prior art described above is used as a fuel injection pump or the like for a vehicle engine, and a relatively low-pressure pump is used. However, when a gear pump is used as a hydraulic pressure source for a vehicle brake device or the like, a pump with a higher pressure specification is required.

In this case, the pressure from the high pressure chamber acts on the gear and the like, and the gear is strongly pressed against the sliding contact surface with the side plate, so that an oil film is not continuously formed between the two sliding contact surfaces. In addition, abrasion, damage, galling and the like are likely to occur on the sliding contact surface.

Further, as another conventional technique, for example, in a gear pump described in Japanese Patent Application Laid-Open No. H10-122160, a flow path for guiding oil in a high pressure chamber between a support shaft of a gear and a support hole of a side plate is provided. In addition to the side plate, a relief groove is provided in the side plate at a position separated from the flow path to allow the support hole to communicate with the low-pressure chamber.

However, in this case, the flow path is not formed on the sliding surface between the side plate and the gear. Further, the relief groove is formed on the sliding contact surface side, but this is merely an auxiliary groove for releasing the oil liquid between the support hole and the low-pressure chamber. An oil film cannot always be formed favorably between the surfaces, and there is a possibility that abrasion, damage, galling or the like may occur on the sliding contact surface.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to form a good oil film on a sliding contact surface between a side plate and a gear, thereby causing abrasion, damage, galling and the like. It is another object of the present invention to provide a gear pump capable of preventing the occurrence of the above problem and ensuring stable pump performance for a long period of time.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is directed to a housing and a left and a right which are disposed in the housing so as to face each other and form a gear chamber between the facing surfaces. Side plates, two gears rotatably supported by the respective side plates via a support shaft and arranged in a meshing state with each other in the gear chamber, and a position on the low pressure side with the meshing portion of each gear interposed therebetween. A low-pressure chamber formed in communication with the inflow port, and a high-pressure chamber formed around the respective gears apart from the low-pressure chamber and communicating with the discharge port, wherein the pair of gears mesh with each other and rotate. Thus, the present invention is applied to a gear pump that sends a liquid from the low pressure chamber to the high pressure chamber.

A feature of the structure adopted by the first aspect of the invention is that a lubricating oil groove is formed on the side plate on a sliding contact surface side with a gear, and one end of the oil groove is formed in the low-pressure chamber. The oil groove communicates with either the high-pressure chamber or a confined space formed between the meshing portions of the gear, and the other end of the oil groove is located on the rear side in the rotation direction of the gear from the one end and the center of the gear. And extends in a direction intersecting a virtual imaginary line passing through.

With this configuration, the low-pressure chamber,
The oil liquid in the high-pressure chamber or the confined space is guided into the oil groove as the gear rotates. The oil groove is arranged such that the other end side is located rearward of one end side with respect to the rotation direction of the gear and is arranged in a direction intersecting the radial direction of the gear, so that a sliding contact surface between the side plate and the gear is provided. As the gear rotates, the oil liquid in the oil groove is sequentially supplied, so that the sliding contact surface can be maintained in a lubricated state.

According to a second aspect of the present invention, a lubricating oil groove is formed in the side plate on the side in contact with the gear, and one end of the oil groove is provided in the low-pressure chamber, the high-pressure chamber or the gear. The other end of the oil groove communicates with one of the confined spaces formed between the meshing portions, and the groove edge of the gear forming the oil groove on the outlet side in the rotation direction has one radius of the gear. It is formed so as to extend rearward in the rotation direction of the gear so that the upper inner peripheral side passes through the groove edge before the outer peripheral side passes through the groove edge.

Thus, the oil liquid in the low-pressure chamber, high-pressure chamber, or the confined space is guided into the oil groove with the rotation of the gear, and the sliding contact surface between the side plate and the gear is provided with the gear. The oil liquid in the oil groove is sequentially supplied with the rotation, so that the sliding contact surface can be kept in a lubricated state.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a gear pump according to an embodiment of the present invention;

FIG. 1 to FIG. 6 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a housing forming an outer shell of the gear pump. The housing 1 has a cylinder hole 2A having a bottom with a circular cross section formed inside, and one end of the cylinder hole 2A is closed as a bottom 2B. And a lid 3 fixed to the other side of the case 2 so as to close the open end 2C side of the case 2.

Reference numeral 4 denotes a pump assembly provided in the housing 1. The pump assembly 4 includes side plates 5, 6, gears 8, 9 and a seal block 12, which will be described later. Then, these side plates 5, 6, gears 8, 9 and seal block 12 are housed in the housing 1 before being housed.
For example, annular metal coil springs (not shown) are
By being wound around the outer peripheral side of the seal block 12, the pump assembly 4 is assembled.

Reference numerals 5 and 6 denote a pair of side plates disposed so as to sandwich the gears 8 and 9 from both the left and right sides. The side plates 5 and 6 have a substantially elliptical shape as shown in FIGS. The gear chamber 7 is formed between the opposing surfaces. The side plates 5 and 6 are housed in the housing 1 together with the gears 8 and 9 in a state of being assembled as the pump assembly 4.

The side plate 5 is provided with support holes 5A and 5B which are spaced apart in the radial direction of the gears 8 and 9 and extend in the axial direction. The side plate 6 has support holes corresponding to the support holes 5A and 5B. 6A, 6
B is drilled. And these support holes 5A, 6
A rotatably supports shaft portions 8B and 8C described later, and support holes 5B and 6B rotatably support shaft portions 9B and 9C described later.

As shown in FIGS. 2 to 5, the side plates 5 and 6 are formed with arc-shaped notches 5C and 6C on the side of the abutting surface with the seal block 12, and the notches 5C and 6C are supported. It extends over the entire width of the side plates 5, 6 in parallel with the holes 5A, 5B, 6A, 6B. The notches 5C and 6C are located between the support holes 5A and 6A and the support holes 5B and 6B, and form an inflow port 14 described later between the support block 5A and the arc groove 12C of the seal block 12.

A pair of gears 8 and 9 are provided in a gear chamber 7 between the side plates 5 and 6 so as to mesh with each other.
As shown in FIG. 1, a disk-shaped gear portion 8A, 9A and a shaft portion 8 extending from the center of the gear portion 8A, 9A to one side in the axial direction.
B, 9B, and shaft portions 8C, 9C extending from the center side of the gear portions 8A, 9A to the other side in the axial direction.

The shaft portions 8B and 8C are located coaxially with the gear portion 8A interposed therebetween, and constitute a support shaft of the gear 8 on the driving side. Further, the shaft portions 9B and 9C are coaxially located with the gear portion 9A interposed therebetween, and constitute a support shaft of the gear 9 on the driven side.

Here, the shaft 8B of the driving gear 8 is rotatably inserted into the support hole 5A of the side plate 5, and the front end of the gear 8 is supported on the bottom 2B side of the case 2 via a bearing 10. Have been. The shaft portion 8C of the gear 8 is rotatably inserted into the support hole 6A of the side plate 6, and the distal end side thereof is supported by the lid 3 via a bearing 11. The distal end side of the shaft portion 8C protrudes outside the lid 3, and the protruding end side is connected to a drive source (not shown) such as an engine or an electric motor.

The gear 9 on the driven side has a shaft portion 9B formed by the side plate 5.
Is rotatably inserted into the support hole 5B, and the front end side thereof is pivotally supported on the bottom 2B side of the case 2. The shaft portion 9C of the gear 9 is rotatably inserted into the support hole 6B of the side plate 6, and the distal end side thereof is pivotally supported by the lid 3. The driven gear 9 is driven to rotate following the driving gear 8 by engaging the gear 9A with the driving gear 8A.

Further, the meshing portions of the gears 8 and 9 are
As shown in FIG. 1, an oil liquid confined space S is formed between the meshing tooth surfaces. The confinement space S is located between the escape grooves 17 and 18 to be described later, and even if a so-called “confinement pressure” is generated in the confinement space S between the tooth surfaces at the meshing portion of the gears 8 and 9, The pressure can be released to the low-pressure chamber 13 or the high-pressure chamber 15 through the escape grooves 17 and 18.

Reference numeral 12 denotes a seal block which constitutes a part of the pump assembly 4. The seal block 12 is provided by abutting against the side plates 5 and 6 from the side as shown in FIGS. In this state, it is detachably attached to the side plates 5 and 6 by the annular metal coil spring.

The seal block 12 has side plates 5,
The upper and lower concave curved surface portions 12 which are concavely cut away along the tooth tips of the gears 8 and 9 on the side of the abutting surface with the gear 6 and 9 as shown in FIG.
A, 12B and an arc groove 12C formed between the concave curved surface portions 12A, 12B and formed as an arc-shaped concave groove are provided.

The seal block 12 has a length ranging from one side surface of the side plate 5 shown in FIG. 1 to the other side surface of the side plate 6, and is concavely curved so as to extend leftward and rightward over its entire length. The surface portions 12A and 12B and the arc groove 12C are formed.

Reference numeral 13 denotes a low-pressure chamber located in the gear chamber 7 between the side plates 5 and 6 and defined between the gears 8 and 9 and the seal block 12. The low-pressure chamber 13 is, as shown in FIG. Gears 8, 9
Is formed between the meshing part of the seal block 12 and the arc groove 12C of the seal block 12, and is always in communication with the inflow port 14 for sucking the oil liquid.

Here, the inflow port 14 is formed by notches 5C and 6C of the side plates 5 and 6 and an arc groove 12C of the seal block 12.
Thus, it is formed as a circular passage extending in the axial direction of the housing 1, and is connected to an external hydraulic oil tank (not shown) through a through hole 14A indicated by a dotted line in FIG.
The through hole 14 </ b> A is formed in the bottom 2 </ b> B of the case 2 and forms a part of the inflow port 14.

A high-pressure chamber 15 is formed between the cylinder hole 2A in the housing 1 and the pump assembly 4. The high-pressure chamber 15 is located around the gears 8 and 9 and is different from the low-pressure chamber 13. And is separated from the low-pressure chamber 13 and the inflow port 14 in the pump assembly 4 by using seal members 27 and the like described later. The high-pressure chamber 15 is filled with high-pressure oil liquid (pressure oil) by rotation of the gears 8 and 9.

That is, the gears 8 and 9 are driven to rotate in the directions indicated by arrows A and B in FIG. 3 to sequentially send the oil liquid guided to the low pressure chamber 13 to the surrounding high pressure chamber 15 side. High pressure chamber 15
In a state where the inside is filled with a high-pressure oil liquid, a discharge port 16 described later is used.
From the housing 1 is discharged to the outside of the housing 1.

Reference numeral 16 denotes a discharge port formed in the housing 1. The discharge port 16 is formed on the bottom 2B side of the case 2 and is always in communication with the high-pressure chamber 15 in the housing 1. The discharge port 16 discharges the pressure oil filling the high-pressure chamber 15 toward an external brake device (not shown) or the like.

Reference numerals 17 and 18 denote escape grooves for preventing the phenomenon of closing the oil liquid in the gear chamber 7. The escape grooves 17 and 18 are provided on the sliding contact surfaces of the side plates 5 and 6 with the gear portions 8A and 9A. The gears 8 and 9 are formed so as to sandwich the meshing portions of the gears 8 and 9 from front and rear. Although FIGS. 3 to 5 show relief grooves 17 and 18 formed on the sliding surface side of the side plate 5, similar relief grooves 17 and 18 are also formed on the sliding surface side of the side plate 6.
18 are formed.

The relief groove 17 on the low pressure side among the relief grooves 17 and 18 is formed as a flat U-shaped shallow bottom groove as shown in FIG. 5 and is always in communication with the low pressure chamber 13. Also,
The high-pressure side relief groove 18 is elongated in the lateral direction with a predetermined distance from the low-pressure side relief groove 17, and is always in communication with the high-pressure chamber 15 as shown in FIG. As a result, even if confinement pressure is generated in the confinement space S shown in FIG. 3 at the meshing portion of the gears 8 and 9, the escape grooves 17 and 18 reduce the confinement pressure to the low-pressure chamber 13 or the high-pressure chamber 15. Is to escape to the side.

Reference numerals 19 and 20 denote lubricating oil grooves formed on the sliding surfaces of the side plates 5 and 6 (only the side plate 5 side is shown).
As shown in FIGS. 4 and 5, one end of each of the oil grooves 19 and 20 communicates with the low-pressure chamber 13 through an escape groove 17 near the meshing portion of the gears 8 and 9, and the other end of each of the gears 8 and 9 as shown in FIGS. Rotation direction (Fig. 3
Arrows A and B in the middle) extend to the rear side, and an annular groove 2 described later
It is connected to 1,22.

The oil grooves 19 and 20 extend substantially tangentially to the annular grooves 21 and 22 toward the rear side in the rotational direction of the gears 8 and 9, respectively. The extending direction is as shown in FIG. The direction intersects a radial virtual line L passing through the center O of the shaft portions 8B, 9B of the gears 8, 9.

In other words, at least the oil grooves 19, 2
Groove edge 19 on the outlet side in the rotation direction of the gears 8 and 9 forming
A and 20A are the shaft portions 8 of the gears 8 and 9 as shown in FIG.
When one radial virtual line L passing through the center O of B, 9B is rotated in the rotational direction of the gears 8, 9 with the center O,
Before the inner peripheral side of the imaginary line L passes through the groove edges 19A and 20A, the outer peripheral side of the imaginary line L is located on the groove edge 19A.
A, 20A.

That is, the oil grooves 19 and 20 extend obliquely rearward from the position of the clearance groove 17 in the rotation direction of the gears 8 and 9, and have an inverted "U" shape as a whole. . The oil grooves 19 and 20 have a substantially U-shaped cross section as shown in FIG.
Tapered notches 19A and 20A are provided at the ends in the B direction.

The low pressure chamber 1 is provided in the oil grooves 19 and 20.
The oil liquid from 3 (escape groove 17) is guided by rotation of gears 8 and 9, and this oil liquid fills oil grooves 19 and 20 and is also supplied to annular grooves 21 and 22 side. This allows
The oil liquid filling the oil grooves 19 and 20 and the annular grooves 21 and 22 is supplied to the side plates 5 and 6 and the gears 8 and 9 as the gears 8 and 9 rotate.
9 is supplied to the sliding contact surface between them, and the two sliding contact surfaces are always kept in a lubricated state.

21 and 22 are side plates 5 for gears 8 and 9 respectively.
6, each of the annular grooves 21 located on the upper side of the annular grooves 21 and 22 is provided with a corresponding one of the side plates 5 and 6 as shown in FIGS. Support holes 5A, 6
It is located around A and is formed so as to surround the shaft portions 8B and 8C of the gear 8 from the outer peripheral side. Each annular groove 22 located on the lower side is located around the support holes 5B, 6B of the side plates 5, 6, and is formed so as to surround the shaft portions 9B, 9C of the gear 9 from the outer peripheral side.

Reference numerals 23 and 24 denote other annular grooves formed on the outer surfaces of the side plates 5 and 6, respectively.
Numeral 4 is located on the outer surface of the side plates 5 and 6 which are in contact with the bottom 2B of the case 2 and the lid 3, and is provided around the support holes 5A, 5B, 6A and 6B similarly to the annular grooves 21 and 22. Is formed.

Each of the annular grooves 21 and 23 communicates with each other via axial grooves 25 and 25 formed on the peripheral wall side of the support holes 5A and 6A as shown in FIGS. The annular grooves 22, 24 also communicate with one another via axial grooves 26, 26 formed on the peripheral wall side of the support holes 5B, 6B.

Thus, the support holes 5A, 6 of the side plates 5, 6 are formed.
A (5B, 6B) and the shaft portions 8B, 8C (9B, 9C) are between the annular groove 21 (22), the axial groove 25 (26), and the annular liquid 23 (24). Is maintained in a lubricated state.

Reference numerals 27, 27 denote sealing members provided on the outer surfaces of the side plates 5, 6, and each of the sealing members 27 is a side plate 5, 6 which is in contact with the bottom 2B of the case 2 and the lid 3. The inside of the pump assembly 4 is shut off from the high-pressure chamber 15 by sealing between the housing 1 and the side plates 5 and 6.

The gear pump according to the present embodiment has the above-described configuration. Next, the operation of the gear pump will be described.

First, when the gear 8 is driven to rotate in the direction of arrow A in FIG. 3 by an external drive source, the gear 9 meshing with the gear 8 is driven to rotate in the direction of arrow B. And gears 8, 9
The oil liquid guided to the low-pressure chamber 13 from the inflow port 14 side by the rotation of the seal block 12 is rotated by the teeth of the gears 8 and 9.
The liquid is sequentially sent to the high-pressure chamber 15 along the concave curved surface portions 12A and 12B, and the high-pressure chamber 15 is filled with high-pressure oil liquid.

The pressure oil in the high-pressure chamber 15 is discharged from the discharge port 16 of the housing 1 to the outside, and is supplied to, for example, a brake device of the vehicle via a hydraulic pressure control valve (not shown). The brake control of the vehicle is performed.

Incidentally, the pressure in the high-pressure chamber 15 of the housing 1 is increased to a pressure equivalent to the brake fluid pressure. When this high pressure acts on the surfaces of the side plates 5 and 6 on the side of the seal member 27 and the outer peripheral side of the seal member 27, the gears 8 and 9 are strongly pressed against the sliding contact surfaces with the side plates 5 and 6, so that both gears are pressed. Unless an oil film is continuously formed between the sliding surfaces, abrasion, damage, galling and the like are likely to occur.

Therefore, in the present embodiment, oil grooves 19, 20 are provided on the sliding surfaces of the side plates 5, 6 with the gear portions 8A, 9A of the gears 8, 9, and the oil grooves 19, 20 have one end. The side communicates with the low-pressure chamber 13 through the escape groove 17 in the vicinity of the meshing portion of the gears 8 and 9, and the other end side has shaft portions 8B and 9B (8C and 9C)
It is configured to communicate with the surrounding annular grooves 21 and 22.

The oil grooves 19, 20 extend obliquely rearward from the position of the clearance groove 17 in the direction of rotation of the gears 8, 9, and form an inverted "C" shape as a whole. 2
2 in a tangential direction. Oil grooves 19 and 20
5 is configured to extend in a direction intersecting a radial virtual line L passing through the center O of the shaft portions 8B, 9B of the gears 8, 9 as shown in FIG.

Thus, the oil liquid from the low pressure chamber 13 (the escape groove 17) is guided into the oil grooves 19 and 20 with the rotation of the gears 8 and 9, and the oil liquid flows through the oil grooves 19 and 20. Filled and supplied to the annular grooves 21 and 22 as well. The rotation of the gears 8 and 9 causes the oil grooves 19 and 20 and the annular groove 2 to rotate.
1 and 22 are filled with the oil liquid, and the side plates 5 and 6 and the gears 8 and 9
Can be sequentially supplied as lubricating oil to the sliding contact surface between the two, and the two sliding contact surfaces can always be kept in a lubricated state.

The oil grooves 19 and 20 have a substantially U-shaped cross section as shown in FIG. 6, and tapered end portions in the directions indicated by arrows A and B, which are the rotation directions of the gears 8 and 9, respectively. Notch 19A,
Since the gears 20A are formed, the oil liquid in the oil grooves 19, 20 can be supplied by the rotation of the gears 8, 9 so as to adhere to the sliding surfaces of the gears 8, 9 from the notch portions 19A, 20A. An oil film can be favorably formed on the sliding surfaces between the side plates 5 and 6 and the gears 8 and 9.

The oil grooves 19 and 20 extend obliquely from the position of the low-pressure chamber 13 (relief groove 17) in the direction of rotation of the gears 8 and 9, and have an inverted "C" shape as a whole. Since it is tangentially connected to the grooves 21 and 22, the gear 8,
The oil grooves 19 and 20 and the annular grooves 21 and 22 are arranged so that the oil liquid is wound in the direction of the arrow in FIG.
And these oil grooves 19, 20 and annular grooves 21,
By continuing to fill the oil liquid into the side plates 22, the side plates 5, 6
A uniform oil film can be secured on the sliding surfaces between the gears and the gears 8 and 9.

Therefore, according to the present embodiment, the side plates 5,
An oil film can be satisfactorily formed on the sliding contact surfaces between the gears 6 and the gears 8 and 9 to prevent abrasion, damage, galling, etc., as well as to improve durability and life, and to provide a long term A stable pump performance can be ensured throughout.

In the first embodiment, the oil groove 1
Although it has been described that the grooves 9 and 20 are formed to have a substantially U-shaped cross-sectional shape as shown in FIG. 6, instead of this, for example, as in a first modified example shown in FIG. It is formed in a substantially triangular cross-sectional shape, and has a tapered notch 119 at the end in the directions indicated by arrows A and B, which are the rotation directions of the gears 8 and 9.
A, 120A may be added.

Further, as in a second modified example shown in FIG. 8, for example, the oil grooves 219 and 220 have a substantially U-shaped cross section, the corners of which are formed in an arc shape, and the gears 8 and 9 have the same shape. A configuration in which tapered notches 219A and 220A are attached to the ends in the directions indicated by arrows A and B, which are the rotation directions, may be employed.

Further, for example, as in a third modification shown in FIG. 9, the oil grooves 319 and 320 are formed to have a substantially semicircular cross-sectional shape, and arrows A and B indicating the rotation directions of the gears 8 and 9 are used. The ends in the direction may be provided with tapered notches 319A and 320A.

Next, FIG. 10 shows a second embodiment of the present invention. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. It shall be. However, a feature of the present embodiment is that the oil grooves 31 and 32 formed on the sliding contact surface of the side plate 5 are configured to spirally extend around the annular grooves 21 and 22 for about one round. .

Here, the oil grooves 31 and 32 have a low pressure through an escape groove 17 in the vicinity of the meshing portion of the gears 8 and 9 at one end side, similarly to the oil grooves 19 and 20 described in the first embodiment. Room 1
3 and extends obliquely rearward from the position of the clearance groove 17 in the rotational direction of the gears 8 and 9. However, oil groove 3
The other ends of the gears 1 and 32 spirally extend around the annular grooves 21 and 22 along the rotation direction of the gears 8 and 9.

The leading ends of the oil grooves 31 and 32 are located substantially one round around the annular grooves 21 and 22,
It is connected in a substantially tangential direction to 1,2. Thus, the oil grooves 31 and 32 are configured to extend in a direction intersecting the radial direction of the gears 8 and 9. FIG.
Although not shown in FIG. 0, oil grooves similar to the oil grooves 31 and 32 of the side plate 5 are also formed on the sliding contact surface side of the side plate 6 disposed to face the side plate 5.

Thus, also in the present embodiment having such a configuration, it is possible to obtain substantially the same operation and effect as in the first embodiment. In the present embodiment, in particular, oil grooves 31 and 3 extending spirally around annular grooves 21 and 22.
By employing No. 2, a more uniform oil film can be formed on the sliding contact surfaces between the side plates 5 and 6 and the gears 8 and 9 over the entire surface.

Next, FIG. 11 shows a third embodiment of the present invention. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. It shall be. However, a feature of the present embodiment is that the sliding grooves of the side plates 5 communicate with each other between the annular grooves 21 and 22 to provide a communication groove 41 having an inverted "U" shape as a whole. .

Here, the communication groove 41 is located between the low-pressure chamber 13 and the escape groove 18 on the high-pressure side, and can communicate with the confined space S between the gears 8 and 9 (see FIG. 3). And an inclined groove 4 as an oil groove having one end communicating with the intermediate groove 42 and the other end communicating with the annular grooves 21 and 22.
3, 44.

The connecting groove 41 is different from the inclined groove 4 except that the intermediate groove 42 is slightly separated from the low-pressure chamber 13.
Reference numerals 3 and 44 have substantially the same configuration as the oil grooves 19 and 20 described in the first embodiment.

However, in the present embodiment, the intermediate groove portion 42 of the communication groove 41 is formed between the low pressure chamber 13 and the high pressure side escape groove 18.
And between the gears 8 and 9 can communicate with the confined space S between the gears 8 and 9 (see FIG. 3). Intermediate groove 42 with rotation
The inside of the inclined grooves 43 and 44 is filled with an oil liquid, and the oil liquid is sequentially supplied to the annular grooves 21 and 22 via the inclined grooves 43 and 44.

In this case, the notch 5C 'of the side plate 5 which forms the inflow port 14 with the arc groove 12C of the seal block 12 has an inverted bottom on the bottom side corresponding to the shape of the communication groove 41. It is shaped like a letter. In addition, a contact groove similar to the contact groove 41 of the side plate 5 is formed on the sliding contact surface side of the side plate 6 arranged to face the side plate 5.

Thus, in the present embodiment configured as described above, substantially the same operation and effect as in the first embodiment can be obtained. In the present embodiment, in particular, since the intermediate groove 42 of the communication groove 41 communicates with the confined space S (see FIG. 3) between the low-pressure chamber 13 and the high-pressure relief groove 18, the gear 8 The pressurized oil liquid confined between the tooth surfaces of the first and second gears 9 and 9 is rotated.
Can be supplied within.

In addition, it is possible to prevent an increase in rotational torque to the gears 8 and 9 due to the confinement pressure in the confinement space S, and to obtain a cooling effect and a wear powder removing effect.

Next, FIG. 12 shows a fourth embodiment of the present invention. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. It shall be. However, a feature of the present embodiment is that the high-pressure side relief groove 51 formed on the sliding contact surface of the side plate 5 is formed as a wide groove, and lubrication oil grooves 52 and 53 are provided at the leading end side of the relief groove 51. It is in the configuration.

Here, the escape groove 51 on the high pressure side is always in communication with the high pressure chamber 15 similarly to the escape groove 18 described in the first embodiment, and extends in a direction crossing the annular grooves 21 and 22 to extend to the low pressure side. Is separated from the escape groove 17. However, the clearance groove 51 of the present embodiment is formed wider than the clearance groove 18 and is configured to be connected to the lubrication oil grooves 52 and 53 almost linearly.

One end of each of the oil grooves 52 and 53 is located in the vicinity of the meshing portion of the gears 8 and 9 through the relief groove 51 and the high-pressure chamber 15.
(See FIG. 4), and the other end side extends linearly toward the escape groove 17 and is close to the annular grooves 21 and 22. Also,
The oil grooves 52 and 53 have a U-shaped planar shape,
The position between the gears 1 and 22 extends in a direction orthogonal (intersecting) with a line segment OO connecting the axes O of the gears 8 and 9. Although not shown in FIG. 12, the oil groove 52 of the side plate 5,
An oil groove similar to 53 is formed.

Thus, also in the present embodiment having such a configuration, it is possible to obtain substantially the same operation and effect as in the first embodiment. In particular, in the present embodiment, the oil grooves 52, 53 can be filled with the high-pressure oil liquid by connecting the oil grooves 52, 53 to the high-pressure relief groove 51. An oil film can be formed satisfactorily on the sliding contact surfaces with 8, 9.

Also in this case, an increase in the rotational torque of the gears 8 and 9 due to the confinement pressure can be prevented, and a cooling effect and an abrasion powder removing effect can be obtained. Further, the oil grooves 52 and 53 are provided with the escape grooves 51 near the meshing portions of the gears 8 and 9.
Extends linearly from the tip of the oil pump, and is spaced apart from the low pressure side relief groove 17 and the annular grooves 21 and 22, so that the pressure drop due to the leakage of the pressure oil is minimized, and the lubrication is performed without lowering the pump efficiency. Performance can be enhanced.

Next, FIGS. 13 and 14 show a fifth embodiment of the present invention.
The present embodiment is characterized in that an oil groove which is always in communication with the high-pressure chamber is formed on the sliding surface side of the side plate with respect to the gear, and an inflow port is provided between the housing and the side plate in the housing. In this case, a seal member for shutting off the airflow is provided. Note that also in the present embodiment, the first
The same reference numerals are given to the same components as those of the embodiment, and the description thereof will be omitted.

In the figure, reference numeral 61 denotes an O-ring as a sealing member for blocking the inflow port 14 from the high-pressure chamber 15 in the housing 1. The O-ring 61 is provided in FIGS. 1 and 2 described in the first embodiment. 1 and is disposed between the lid 3 and the side plate 6 illustrated in FIG.
The O-ring 61 is also provided between the bottom 2B of the case 2 and the side plate 5.

As shown in FIG. 13, the O-ring 61 surrounds the inflow port 14 in a ring shape from the outside. For example, the lubricating oil liquid supplied into the annular grooves 23, 24 around the shafts 8C, 9C is filled with oil. Leakage to the inflow port 14 side is prevented. Thereby, the pressure oil in the high-pressure chamber 15 is supplied to the inflow port 1.
4 and can be maintained at a high pressure state in the high pressure chamber 15.

Reference numerals 62 and 63 denote oil grooves formed on the sliding surface side of the side plate 5. The oil grooves 62 and 63 have substantially the same configuration as the oil grooves 19 and 20 described in the first embodiment. However, one end side of the oil grooves 62 and 63 is different in that it communicates with the high-pressure chamber 15 (see FIG. 13) via the relief groove 18 near the meshing portion of the gears 8 and 9.

The other ends of the oil grooves 62 and 63 extend in a direction intersecting the radial direction of the gears 8 and 9, and the ends thereof are connected to the annular grooves 21 and 22 in a tangential direction. FIG.
Although not shown in FIG. 4, oil grooves similar to the oil grooves 62 and 63 of the side plate 5 are also formed on the sliding contact surface side of the side plate 6 arranged to face the side plate 5.

Thus, in the present embodiment configured as described above, substantially the same operation and effect as those of the first embodiment can be obtained. In particular, in the present embodiment,
The oil grooves 52 and 53 can be filled with high-pressure oil liquid.

As a result, an oil film can be satisfactorily formed on the sliding contact surfaces between the side plates 5 and 6 and the gears 8 and 9, and the annular grooves 21 and
High-pressure oil can also be supplied to 22, 23 and 24,
Support holes 5A, 6A, 5B, 6B and shaft portions 8 of gears 8, 9
B, 8C, 9B and 9C can be maintained in a lubricated state by high-pressure oil.

The O-ring 61 prevents the high-pressure oil from leaking to the low-pressure side (the inflow port 14 side), thereby effectively suppressing the pressure drop and improving the lubrication performance without lowering the pump efficiency. Can be.

Note that in the second embodiment,
The oil grooves 31, 32 may be formed as concave grooves having a U-shaped cross section as shown in FIG. 6, or may be formed as in the respective modified examples illustrated in FIGS. is there. And
This point is the same in the third to fifth embodiments.

[0084]

As described above in detail, according to the first aspect of the present invention, a lubricating oil groove is formed on the sliding contact surface between the side plate and the gear, and one end of the oil groove has a low pressure chamber and a high pressure chamber. Alternatively, it communicates with one of the confined spaces formed between the meshing portions of the gears, and the other end is located on the rear side in the rotational direction of the gear and extends in a direction intersecting a radial imaginary line passing through the center of the gear. With this configuration, the oil liquid in the low-pressure chamber, high-pressure chamber, or confined space can be guided into the oil groove with the rotation of the gear, and is arranged in a direction that extends in the gear rotation direction and intersects the radial direction of the gear. The oil liquid in the oil groove can be sequentially supplied to the sliding contact surface between the side plate and the gear. Therefore, an oil film can be formed satisfactorily on the sliding surface between the side plate and the gear, and the sliding surface can be maintained in a lubricated state, and at the same time, it is possible to prevent abrasion, damage, galling, etc. Stable pump performance can be secured.

According to the second aspect of the present invention, a lubricating oil groove is formed in the side plate on the side in contact with the gear, and one end of the oil groove is provided in the low-pressure chamber, the high-pressure chamber, or the gear. The oil groove communicates with one of the confined spaces formed between the meshing portions of the gear, and the other end of the oil groove has a groove edge on the rotation direction outlet side of the gear forming the oil groove. Since the inner circumferential side on the radius extends rearward in the rotation direction of the gear so that the outer circumferential side passes through the groove edge before passing through the groove edge, the low pressure chamber, the high pressure chamber, or the closed The oil liquid in the storage space can be guided into the oil groove with the rotation of the gear, and the oil liquid in the oil groove can be sequentially supplied to the sliding contact surface between the side plate and the gear. Therefore, an oil film can be satisfactorily formed on the sliding contact surface between the side plate and the gear,
The sliding surface can be kept in a lubricated state, and at the same time, the occurrence of abrasion, damage, galling and the like can be prevented, and stable pump performance can be ensured for a long period of time.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a gear pump according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the gear pump as viewed from the direction of arrows II-II in FIG.

FIG. 3 is a sectional view of the gear pump as viewed from the direction of arrows III-III in FIG. 1;

FIG. 4 is a sectional view of the gear pump as viewed from the direction of arrows IV-IV in FIG. 1;

FIG. 5 is an enlarged view of a main part of FIG. 4 showing an oil groove and the like formed on a sliding contact surface of a side plate.

FIG. 6 is an enlarged cross-sectional view showing an oil groove in FIG. 5;

FIG. 7 is an enlarged cross-sectional view showing an oil groove according to a first modified example.

FIG. 8 is an enlarged cross-sectional view showing an oil groove according to a second modified example.

FIG. 9 is an enlarged cross-sectional view showing an oil groove according to a third modified example.

FIG. 10 is a longitudinal sectional view of the same position as FIG. 5 showing an oil groove and the like of a gear pump according to a second embodiment.

FIG. 11 is a longitudinal sectional view of the same position as FIG. 5 showing a communication groove and the like of a gear pump according to a third embodiment.

FIG. 12 is a longitudinal sectional view of the same position as FIG. 5 showing an oil groove and the like of a gear pump according to a fourth embodiment.

FIG. 13 is a longitudinal sectional view showing a gear pump according to a fifth embodiment at the same position as in FIG. 2;

14 shows an oil groove and the like of the gear pump shown in FIG.
It is a longitudinal cross-sectional view of the same position as.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Housing 2 Case 3 Lid 4 Pump assembly 5, 6 Side plate 7 Gear chamber 8, 9 Gear 8A, 9A Gear part 8B, 8C, 9B, 9C Shaft part 12 Seal block 13 Low pressure chamber 14 Inflow port 15 High pressure chamber 16 Discharge Ports 19, 20, 31, 32, 52, 53, 62, 63, 1
19, 120, 219, 220, 319, 320 Oil groove 21, 22 Annular groove 41 Communication groove 42 Intermediate groove 43, 44 Inclined groove (oil groove) L Virtual line O Center of gear S Confinement space

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Junichi Ikeda 1-3-6 Fujimi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Tokiko Corporation F-term (reference) 3H041 AA02 BB02 CC07 CC13 DD04 DD05 DD15 3H044 AA02 BB02 CC07 CC12 DD04 DD05 DD11

Claims (2)

[Claims] 1. A gear, comprising: a housing; left and right side plates arranged in the housing so as to face each other and forming a gear chamber between the opposing surfaces; and the gears rotatably supported by the respective side plates via a support shaft. Two gears arranged in mesh with each other in the chamber, a low-pressure chamber formed at a position on the low-pressure side across the meshing portion of each gear and communicating with the inflow port, and separated from the low-pressure chamber. A high-pressure chamber formed around each gear and communicating with a discharge port, wherein the pair of gears mesh with each other and rotate to transmit liquid from the low-pressure chamber toward the high-pressure chamber; Has a lubricating oil groove formed on the sliding contact surface side with the gear, and one end of the oil groove communicates with one of the low-pressure chamber, the high-pressure chamber, and the confined space formed between the meshing portions of the gear. And the other end of the oil groove is closer to the gear than the one end. Gear pump which is characterized by being configured to extend in a direction translocation is located in the direction the rear side intersects the imaginary line in the radial direction passing through the center of the gear. 2. A gear, comprising: a housing; left and right side plates arranged in the housing so as to face each other and forming a gear chamber between the opposing surfaces; and the gears rotatably supported by the respective side plates via a support shaft. Two gears arranged in mesh with each other in the chamber, a low-pressure chamber formed at a position on the low-pressure side across the meshing portion of each gear and communicating with the inflow port, and separated from the low-pressure chamber. A high-pressure chamber formed around each gear and communicating with a discharge port, wherein the pair of gears mesh with each other and rotate to transmit liquid from the low-pressure chamber toward the high-pressure chamber; Has a lubricating oil groove formed on the sliding contact surface side with the gear, and one end of the oil groove communicates with one of the low-pressure chamber, the high-pressure chamber, and the confined space formed between the meshing portions of the gear. The other end of the oil groove is provided with a gear that forms the oil groove. The groove edge on the exit side in the rolling direction is moved rearward in the rotational direction of the gear so that the inner peripheral side on one radius of the gear passes through the groove edge before the inner peripheral side passes through the groove edge. A gear pump formed so as to extend to the side.