JP2001280260A - Internal gear pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal gear pump free to perform smooth rotation of an internal tooth gear by preventing pressure the internal tooth gear receives from changing as much as possible. SOLUTION: A ring internal tooth gear 4 and an external tooth gear 5 to be engaged with this internal tooth gear 4 are stored free to rotate in a storage recessed part 3 formed on a pump housing 2. A suction port 16 is opened in a suction region in which an engagement clearance increases in accordance with rotation of the gears 4, 5, and a discharge port 17 is opened in a discharge region where the engagement clearance decreases. The storage recessed part 3 is constituted by furnishing an inner peripheral surface 13 to support an outer peripheral surface 12 of the internal tooth gear 4 and an inside surface 15 to support an outer peripheral side side surface 14 of the internal tooth gear 4 as well as continuously formed in the peripheral direction on the both end sides in the axial direction of this inner peripheral surface 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal gear pump capable of supplying hydraulic oil to an automatic transmission or the like of an automobile.

[0002]

2. Description of the Related Art An internal gear pump of this type accommodates a ring-shaped internal gear and an external gear meshing with the internal gear in a housing recess formed in a pump housing in a rotatable manner.
A suction port is opened in a suction area where the mesh gap increases with the rotation of these gears, and a discharge port is opened in a discharge area where the mesh gap decreases, and hydraulic oil is sucked from the suction port and discharged from the discharge port. It discharges.

[0003] As a conventional internal gear pump, for example, Japanese Patent Application Laid-Open No. 8-200238 discloses that the outer peripheral surface of the internal gear is supported by the inner peripheral surface of a housing recess and the outer peripheral side of the internal gear. 1 shows an internal gear pump supported on an inner surface formed on one side in the axial direction of the inner peripheral surface of the housing recess.

[0004]

The internal gear rotates in the housing recess while receiving the pressure of the hydraulic oil from both sides in the axial direction. The inner surface is formed only on one side in the axial direction, particularly near the suction port or the discharge port, and one side on the outer peripheral side of the internal gear is supported on the inner surface. There is a possibility that the pressure applied to the internal gear changes depending on the supported side and the non-supported side.

When the pressure applied to the internal gear changes,
The internal gear moves in the recess and the rotation gap between the internal gear and the recess changes, and on the side where the rotation gap increases, leakage of hydraulic oil may increase through this gap. On the other hand, on the side where the rotation gap is reduced, the internal gear may come into contact with the inner side surface of the housing concave portion and the rotation may not be smooth.

The present invention has been devised in view of the above-mentioned conventional circumstances, and prevents the pressure applied to the internal gear from changing as much as possible so that the internal gear can smoothly rotate. It is an object to provide an internal gear pump.

[0007]

According to the first aspect of the present invention, a ring-shaped internal gear and an external gear meshing with the internal gear are rotatable in a receiving recess formed in the pump housing. An internal gear pump having an intake port opened in a suction area where the meshing gap increases with the rotation of these gears, and a discharge port opened in a discharge area where the meshing gap decreases. The recess has an inner peripheral surface that supports the outer peripheral surface of the internal gear, and an inner surface that is formed continuously in the circumferential direction at both axial ends of the inner peripheral surface and supports the outer peripheral side surface of the internal gear. It has a configuration provided.

According to a second aspect of the present invention, in the configuration of the first aspect of the present invention, the width of the inner surface of the housing recess in the radial direction is equal to each other at positions opposed in the axial direction. It is.

According to a third aspect of the present invention, in the configuration of the first aspect of the present invention, a communication groove communicating with a suction port or a discharge port is formed on an inner surface of the housing recess. .

According to a fourth aspect of the present invention, in the configuration of the third aspect of the present invention, the communication groove is formed on inner surfaces on both sides in the axial direction at positions facing each other.

According to a fifth aspect of the present invention, in the configuration of the third aspect of the invention, among the communication grooves, the opening cross-sectional area of the communication groove communicating with the suction port is smaller than that of the communication groove communicating with the discharge port. It is configured to be formed larger than the cross-sectional area.

According to a sixth aspect of the invention, in the configuration of the third aspect of the invention, the communication groove is formed by casting.

According to a seventh aspect of the present invention, in the configuration of the first aspect, a communication groove communicating with a suction port or a discharge port is formed on an inner surface of the housing recess, and the internal gear is formed. Is formed by chamfering the axial end of the outer peripheral surface of.

According to an eighth aspect of the present invention, in the configuration of the first aspect, a communication groove communicating with a suction port or a discharge port is formed in an inner surface of the housing recess, and the internal gear is formed. Is provided with an oil groove on the outer peripheral surface thereof.

Here, the teeth formed on the internal gear and the external gear may be teeth having an involute curve, a sine curve, a trochoid curve, or the like.

In such a configuration, when the internal gear and the external gear rotate, the hydraulic oil is sucked from the suction port and discharged from the discharge port. That is, the suction port is open to a suction area where the mesh gap increases with rotation of the gear, and the hydraulic oil guided to the suction port is sucked in the suction area, and then the discharge gap decreases. It is transferred to the area and discharged from a discharge port opened to this discharge area.

Here, in the present invention, the housing recess is formed in the inner peripheral surface that supports the outer peripheral surface of the internal gear, and is continuously formed in the axial direction on both ends in the axial direction of the inner peripheral surface. And an inner surface for supporting the outer peripheral side surface of the internal gear.

Thus, the internal gear has an outer peripheral surface supported by the inner peripheral surface of the housing recess and an outer peripheral side surface supported by the inner surface of the housing recess from both sides in the axial direction. The pressure of the hydraulic oil received from both sides in the axial direction becomes substantially equal.

For this reason, the rotation gap between the internal gear and the accommodation recess is prevented as much as possible, and the increase in the rotation gap increases the leakage of hydraulic oil, and the rotation gap reduces the rotation gap. The internal gear is advantageously prevented from contacting the inner surface of the receiving recess.

Therefore, it is possible to obtain an internal gear pump capable of achieving smooth rotation of the internal gear by minimizing a change in the pressure applied to the internal gear.

According to the second aspect of the present invention, since the radial widths of the inner side surfaces of the receiving recesses are formed to be equal to each other at positions opposed to each other in the axial direction, the internal gears are formed on both sides in the axial direction. Can be equalized.

According to the third aspect of the present invention, since the communication groove communicating with the suction port or the discharge port is formed on the inner surface of the storage recess, the hydraulic oil flows from the communication groove into the storage recess. Supplied to the inner surface and the rotation gap, lubrication between the housing recess and the internal gear can be improved.

According to the fourth aspect of the present invention, since the communication groove is formed at a position opposed to each other on the inner side surfaces on both sides in the axial direction, the pressure of the hydraulic oil guided to the communication groove can be increased. The internal gear can be uniformly supported in the axial direction.

According to the fifth aspect of the present invention, among the communication grooves, the opening cross-sectional area of the communication groove communicating with the suction port is formed to be larger than the cross-sectional area of the communication groove communicating with the discharge port. Therefore, while a large amount of hydraulic oil is guided to the communication groove communicating with the suction port, a small amount of hydraulic oil leaks to the discharge port via the communication groove from the rotation gap between the housing recess and the internal gear. As a result, lubrication between the housing recess and the internal gear can be improved.

According to the sixth aspect of the present invention, since the communication groove is formed by casting, the number of processing steps can be reduced.

According to the seventh aspect of the present invention, a communication groove which opens to a suction port or a discharge port is formed in an inner surface of the housing recess, and an axial end of an outer peripheral surface of the internal gear is formed. The hydraulic oil guided from the communication groove is guided to the entire circumference of the internal gear through the gap created by the chamfer, so that lubrication between the housing recess and the internal gear is improved. Can be.

According to the eighth aspect of the present invention, a communication groove that opens to a suction port or a discharge port is formed on the inner surface of the housing recess, and an oil groove is provided on the outer peripheral surface of the internal gear. Therefore, the hydraulic oil guided from the communication groove is guided to the outer periphery of the internal gear through the oil groove, and the lubrication between the housing recess and the internal gear can be improved.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as embodiments applied to a hydraulic pump of an automatic transmission.

FIG. 1 is a sectional view of an internal gear pump showing an embodiment of the present invention, and is a sectional view taken along line AA of FIG. 2, and FIG. 2 is a sectional view of line AA of FIG. FIG. 3 is an enlarged view of a main part of FIG.

In the figure, an internal gear pump denoted by reference numeral 1 has a ring-shaped internal gear 4 and an external gear 5 meshing with the internal gear 4 in a receiving recess 3 formed in the pump housing 2. Are rotatably accommodated with a predetermined rotation gap.

The internal teeth 6 formed on the internal gear 4 and the external teeth 7 formed on the external gear 5 have a tooth shape composed of a higher-order function curve based on a trochoid curve. Further, the number of teeth of the external gear 5 is smaller than the number of teeth of the internal gear 4, whereby the internal gear 4 and the external gear 5
In this state, the rotation center is eccentric to each other by a predetermined dimension, and the internal gear 4 and the external gear 5 rotate with a predetermined meshing gap.

The pump housing 2 is composed of a housing member 9 and a cover member 10 arranged so as to overlap with the housing member 9. The housing recess 3 is formed at a joint between the housing member 9 and the cover member 10. Is formed. The housing member 9 and the cover member 1
0 is connected by connecting bolts 11.

The receiving recess 3 is provided on the outer peripheral surface 1 of the internal gear 4.
2 and an inner side surface 15 formed continuously on both ends in the axial direction of the inner peripheral surface 13 in the circumferential direction and supporting the outer side surface 14 of the internal gear 4. At the same time, a suction port 16 and a discharge port 17 are opened in the housing recess 3.

The suction port 16 is rotated by the rotation of the internal gear 4 and the external gear 5 (rotation in the direction of the arrow in FIG. 2).
The internal gear 4 is formed so as to face a suction region where the mesh gap between the internal teeth 6 of the internal gear 4 and the external teeth 7 of the external gear 5 increases. Further, the suction port 16 is open to the housing recess 3 from both sides in the axial direction, and the housing member 9 and the cover member 1 are opened.
0 (see FIG. 1). That is, the housing concave portion 3 is opened facing both sides in the axial direction.

The discharge port 17 is formed facing the discharge region where the mesh gap is reduced. Further, the discharge port 17 is open from both sides in the axial direction into the housing recess 3 and is formed in both the housing member 9 and the cover member 10 (not shown). That is, the housing concave portion 3 is opened facing both sides in the axial direction.

The suction port 16 and the discharge port 17 are formed radially inward (closer to the rotation center of the external gear 5) by a predetermined dimension from the inner peripheral surface 13 of the housing recess 3.
Thereby, the radial width of the inner side surface 15 of the housing recess 3 is formed to have a predetermined size (w), and
Equal dimensions (w) at axially opposed positions
(See FIG. 3).

The suction port 16 is connected to the pump housing 2.
(The cover member 10) communicates with the suction passage 18 formed therein. Specifically, the suction port 16 formed in the housing member 9 of the suction port 16 branches from a suction passage 18 formed in the cover member 10 of the pump housing 2 via a suction branch passage 19 formed in the housing member 9. The suction port 18 communicates with the suction passage 18, and the suction port 16 formed in the cover member 10 directly communicates with the suction passage 18. Further, the suction passage 18 communicates with a reservoir (not shown) of the hydraulic oil.

On the other hand, the discharge port 17 communicates with a discharge passage 20 formed in (the cover member 10 of) the pump housing 2. More specifically, the discharge port 17 formed in the housing member 9 of the discharge port 17 branches from a discharge passage 20 formed in the cover member 10 of the pump housing 2 and forms a branch discharge passage (not shown) formed in the housing member 9. ), And the discharge port 17 formed in the cover member 10 is connected to the discharge passage 20.
Is in direct communication with Further, the discharge passage 20 communicates with a hydraulic circuit (not shown) of the automatic transmission. In the middle of the discharge passage 20, there is provided an orifice 2 for controlling a flow rate.
1 is provided.

At substantially the center of the pump housing 2, a stator shaft 23 is provided so as to penetrate therethrough. The stator shaft 23 is provided integrally with the cover member 10 in this embodiment, and penetrates the external gear 5 (see FIG. 1).

A hollow torque converter sleeve 25 is disposed on the outer peripheral side of the stator shaft 23.
The distal end thereof can be inserted into the inner diameter side of the external gear 5, and the external gear 5 is rotationally driven by the torque converter sleeve 25. The torque converter sleeve 25 is connected to the stator shaft 23.
Are rotatably supported by a rolling bearing 26 provided on the outer periphery of the housing member 9 and a bearing 27 provided on the inner periphery of the housing member 9.

In such a configuration, the external gear 5 is rotationally driven by the torque converter sleeve 25 disposed on the outer peripheral side of the stator shaft 23, and the internal gear 4 meshing with the external gear 5 is rotated. You. As the internal gear 4 and the external gear 5 rotate, hydraulic oil in a reservoir (not shown) is sucked from the suction port 16 via the suction passage 18 (and the suction branch passage 19), and is discharged from the discharge port 17 Is discharged from. That is, the suction port 16
Are opened in a suction area where the mesh gap increases with the rotation of the gears 4 and 5, and the hydraulic oil guided to the suction port 16 is sucked in the suction area, and then the discharge area where the mesh gap decreases. Discharge port 1 which is transferred to
7 is discharged.

Here, in the present invention, the housing recess 3 has an inner peripheral surface 13 that supports the outer peripheral surface 12 of the internal gear 4.
And an inner side surface 15 continuously formed in both axial ends of the inner peripheral surface 13 in the circumferential direction and supporting the outer peripheral side surface 14 of the internal gear 4.

Thus, the internal gear 4 has the outer peripheral surface 12 supported by the inner peripheral surface 13 of the housing recess 3, and the outer peripheral side surface 14 supported by the inner surface 15 of the housing recess 3 from both sides in the axial direction. As a result, the pressure of the hydraulic oil received from both sides in the axial direction during rotation becomes substantially equal.

Therefore, a change in the rotational gap between the internal gear 4 and the housing recess 3 is prevented as much as possible, and an increase in the rotational gap increases the leakage of hydraulic oil or increases the rotational gap. Due to the reduction, the internal gear 4 becomes the inner surface 1 of the accommodation recess 3.
5 is advantageously prevented.

Therefore, the internal gear pump 1 capable of achieving a smooth rotation of the internal gear 4 while preventing the pressure applied to the internal gear 4 from changing as much as possible is obtained.

Further, since the radial widths of the inner side surfaces 15 of the housing recesses 3 are formed to be equal to each other at positions opposed to each other in the axial direction, the pressures that the internal gear 4 receives from both sides in the axial direction are equalized. Can be.

FIGS. 4 to 10 are views showing another embodiment of the present invention, and these embodiments will be described below. In the description, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted.

The difference between these embodiments is that a communication groove 31 communicating with the suction port 16 or the discharge port 17 is formed in the inner side surface 15 of the housing recess 3.

In these embodiments, the communication groove 31 is formed on one inner peripheral surface 15 of the housing recess 3, that is, the inner peripheral surface 15 on the side of the cover member 10, but is preferably in the axial direction. The inner peripheral surfaces 15 on both sides are formed at positions facing each other. Further, the communication groove 31 is formed in the pump housing 2, that is, the housing member 9 and the cover member 10.
When it is formed by casting including the suction port 16 and the discharge port 17, it can be formed by casting.

In the embodiment shown in FIGS. 4 to 6, the communication groove 31 penetrates in a substantially radial direction, and is open to the suction port 16 side.
It is formed to open to the side.

In the embodiment shown in FIGS. 7 and 8, the communication groove 31 is formed so as to open toward the suction port 16 without penetrating substantially in the radial direction.

Further, the communication passage 31 is provided in each of FIGS.
In the embodiment shown in (1), it is formed so as to open to the suction passage 18 side without penetrating substantially in the radial direction. That is, the communication passage 31 guides the hydraulic oil from the suction port 16 and the suction passage 18 to the sliding surface between the outer peripheral surface 12 and the inner peripheral surface 13.

The communication groove 31 is provided in the suction port 16.
It is possible to provide a communication groove (not shown) communicating with the discharge port 7 together with the communication groove 31 communicating with the discharge port 7. In this case, preferably, the opening cross-sectional area of the communication groove 31 communicating with the suction port 16 is formed larger than the opening area of the communication groove (not shown) communicating with the discharge port 17.

In these embodiments, the axial end of the outer peripheral surface 12 of the internal gear 4 supported by the housing recess 3 can be chamfered (not shown). It is possible to provide an oil groove (not shown) on the outer peripheral surface 12 of the internal gear 4.

With such a configuration, the same operation and effect as described in the above embodiment can be obtained. In addition, since a communication groove 31 communicating with the suction port 16 or the discharge port 17 is formed on the inner side surface 15 of the housing recess 3,
Hydraulic oil is supplied from the communication groove 31 to the inner side surface 15 of the housing recess 3 and the rotation gap, so that lubrication between the housing recess 3 and the internal gear 4 can be improved.

Further, since the communication groove 31 is formed on the inner side surfaces 15 on both sides in the axial direction to face each other, the pressure of the hydraulic oil guided to the communication groove 31 allows the internal gear 4 to move in the axial direction. Can be evenly supported.

Further, among the communication grooves 31, the opening cross-sectional area of the communication groove 31 communicating with the suction port 16 is formed larger than the cross-sectional area of the communication groove (not shown) communicating with the discharge port 17. While a large amount of hydraulic oil is guided to the communication groove 31 communicating with the suction port 16,
Communication groove (not shown) from the rotational gap between the gear and the internal gear 4
The amount of the hydraulic oil leaking to the discharge port 17 via the hole can be reduced, and the lubrication between the housing recess 3 and the internal gear 4 can be improved.

Further, by forming the communication groove 31 by casting, the number of processing steps can be reduced.

The communication groove 3 which opens to the suction port 16 or the discharge port 17 is formed on the inner side surface 15 of the recess 3.
1 as well as chamfering (not shown) the axial end of the outer peripheral surface 12 of the internal gear 4 to form the communication groove 3.
1 is guided to the entire circumference of the internal gear 4 through a gap created by chamfering (not shown), so that lubrication between the housing recess 3 and the internal gear 4 can be improved. it can.

The communication groove 3 which opens to the suction port 16 or the discharge port 17 is formed on the inner side surface 15 of the accommodation recess 3.
1 and an oil groove (not shown) is provided on the outer peripheral surface 12 of the internal gear 4, so that the operating oil guided from the communication groove 31 passes through the oil groove (not shown). The lubrication between the recess 3 and the internal gear 4 can be improved by being guided to the outer periphery of the inner gear 4.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to this embodiment, and can be changed without departing from the spirit of the invention.

[0062]

As described above in detail, according to the present invention, it is possible to prevent the pressure applied to the internal gear from changing as much as possible and to achieve a smooth rotation of the internal gear. An internal gear pump is obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an internal gear pump according to an embodiment of the present invention, which is a cross-sectional view taken along line AA of FIG.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged view showing a main part of FIG. 1;

FIG. 4 is a drawing similar to FIG. 1, showing another embodiment of the present invention.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

6 shows the embodiment shown in FIG. 4 and FIG. 5 in a drawing (a) showing an enlarged main part of FIG. 4 and a drawing (b) showing an enlarged main part of FIG. 5; is there.

FIG. 7 is a view similar to FIG. 6, showing another embodiment of the present invention.

FIG. 8 is a view similar to FIG. 6, illustrating another embodiment of the present invention.

FIG. 9 is a view similar to FIG. 6, showing another embodiment of the present invention.

FIG. 10 is a view similar to FIG. 6, showing another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 internal gear pump 2 pump housing 3 housing recess 4 internal gear 5 external gear 12 outer peripheral surface 13 inner peripheral surface 14 outer peripheral side surface 15 inner surface 16 suction port 17 discharge port

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hirokazu Akiba 1370 Onna, Atsugi-shi, Kanagawa F-term in Unisia Gex Co., Ltd. (reference) 3H041 AA02 BB03 CC05 CC15 CC17 DD01 DD05 DD11 DD12 DD13 DD15 DD38 3H044 AA02 BB03 CC05 CC14 CC16 DD01 DD05 DD11 DD12 DD13 DD28

Claims (8)

[Claims] A ring-shaped internal gear and an external gear meshing with the internal gear are rotatably housed in a housing recess formed in a pump housing, and the mesh gap is formed with the rotation of these gears. Opening the suction port in the suction area where
In an internal gear pump in which a discharge port is opened in a discharge region in which a meshing gap is reduced, the housing concave portion includes an inner peripheral surface that supports an outer peripheral surface of the internal gear, and both ends in the axial direction of the inner peripheral surface. And an inner surface formed continuously in the circumferential direction to support an outer peripheral side surface of the internal gear. 2. The internal gear pump according to claim 1, wherein radial widths of inner side surfaces of the housing recess are formed to be equal to each other at positions opposed in the axial direction. 3. The internal gear pump according to claim 1, wherein a communication groove communicating with a suction port or a discharge port is formed on an inner surface of the housing recess. 4. The communication groove is provided on inner surfaces on both sides in the axial direction.
The internal gear pump according to claim 3, wherein the internal gear pumps are formed at positions facing each other. 5. The communication groove according to claim 3, wherein a cross-sectional area of the communication groove communicating with the suction port is larger than a cross-sectional area of the communication groove communicating with the discharge port. An internal gear pump as described. 6. The internal gear pump according to claim 3, wherein said communication groove is formed by casting. 7. A communication groove communicating with a suction port or a discharge port is formed on an inner surface of the housing recess, and an axial end of an outer peripheral surface of the internal gear is chamfered. The internal gear pump according to claim 1, wherein 8. The internal recess of the receiving recess is formed with a communication groove communicating with a suction port or a discharge port, and an oil groove is provided on an outer peripheral surface of the internal gear. 2. The internal gear pump according to 1.