JP5983130B2 - Inscribed gear pump - Google Patents

Description

  The present invention relates to an internal gear pump that has a structure in which outer teeth of an inner gear are inscribed in the inner teeth of an outer gear, and performs suction and discharge of fluid.

In recent vehicles, a small and efficient internal gear pump having an electric motor is used as a pump for supplying oil to a transmission or the like.
Further, in recent vehicles, improvement in fuel efficiency is an important issue, and each component mounted on the vehicle is required to improve efficiency and reduce weight.
For example, the prior art described in Patent Document 1 discloses an electric pump unit (internal gear pump) that is reduced in size and weight by including an electric motor having an appropriate structure of a rotor and a stator.

JP 2010-116914 A

In the prior art described in Patent Document 1, the electric motor portion is made more compact and lighter, but there remains room for improving the efficiency of the pumping capacity of the internal gear pump composed of the inner gear and the outer gear. Yes. If the efficiency of the pump capacity is improved, the size and weight can be further reduced, which can contribute to further improvement in fuel consumption.
The present invention has been devised in view of such points, and an object of the present invention is to provide an internal gear pump that can further improve the efficiency of the pumping capacity and can be further reduced in size and weight.

In order to solve the above problems, the internal gear pump according to the present invention takes the following means.
First, the first invention of the present invention is a pump housing having a housing recess that opens on one end side, a pump plate that is attached to one end of the pump housing and forms a gear housing space by closing the housing recess, An outer gear that is rotatably accommodated in the gear accommodating space and has inner teeth on an inner peripheral surface, an inner gear that has outer teeth on the outer peripheral surface that mesh with the inner teeth of the outer gear, and a bottom portion of the housing recess of the pump housing A shaft member that is inserted into the formed through hole and that is fitted in the shaft hole of the inner gear and is capable of rotating the inner gear, and forms the gear housing space on the surface of the pump housing to form the pump A concave housing side suction port and a concave housing side discharge port are formed on the surface facing the plate. A concave plate side suction port having the same shape as the housing side suction port is formed at a position facing the housing side suction port in the pump plate, and faces the housing side discharge port in the pump plate. It is an internal gear pump in which a concave plate side discharge port having the same shape as the housing side discharge port is formed at a position.
A housing-side high-pressure generating groove that is tapered toward the leakage direction of the fluid leaking from the housing-side discharge port is provided at least at a part of the periphery of the housing-side discharge port in the pump housing. .
A plate-side high-pressure generating groove that tapers in the direction of leakage of fluid leaking from the plate-side discharge port is provided at a position facing the housing-side high-pressure generating groove in the pump plate.

In the first aspect of the invention, a housing-side high-pressure generating groove, which is a groove for generating pressure by the flow of fluid leaking from the housing-side discharge port where the fluid pressure increases, is provided. Similarly, a plate-side high-pressure generating groove, which is a groove for generating pressure by the flow of fluid leaking from the plate-side discharge port where the fluid pressure increases, is provided.
Thereby, using the flow of the leaked fluid, a high-pressure portion is formed at the leaked portion to suppress the leak amount, to further improve the efficiency of the pump capacity, and to promote further downsizing and weight reduction. .
Further, by providing the housing side high pressure generating groove and the plate side high pressure generating groove at opposite positions, it is possible to prevent the inner gear and the outer gear from coming into contact with the pump housing or the pump plate and increasing the wear of the inner gear and the outer gear. Can do.

Next, the second invention of the present invention is the internal gear pump according to the first invention, wherein both the housing side suction port and the housing side discharge port have a substantially crescent shape, and a substantially crescent shape. The plate-side suction port and the plate-side discharge port are both substantially crescent-shaped, and the recess in the substantially crescent-shaped shape is provided. It arrange | positions so that it may mutually oppose and a mutual edge part may oppose.
The housing-side high-pressure generating groove has the housing-side discharge port in two port-facing regions, which are regions where the end of the housing-side suction port and the end of the housing-side discharge port face each other. A direction facing the end of the housing side suction port facing from the end of the port is provided in a port facing region on the side where the direction of rotation of the inner gear is the same, and facing from the end of the housing side discharge port It is provided so that it may become tapered toward the end of the housing side suction port.
The plate-side high-pressure generating groove is provided at a position facing the housing-side high-pressure generating groove in the pump plate, and the end of the plate-side suction port facing from the end of the plate-side discharge port. It is provided so as to be tapered toward the part.

According to the second aspect of the invention, the housing-side high-pressure generating groove and the plate-side high-pressure generating groove are provided at the location where the amount of fluid leakage is estimated to be the largest.
Thereby, the amount of fluid leakage from the housing side discharge port and the plate side discharge port can be efficiently suppressed.

Next, a third invention of the present invention is the internal gear pump according to the first invention, wherein each of the housing side suction port and the housing side discharge port has a substantially crescent shape, and a substantially crescent shape. The plate-side suction port and the plate-side discharge port are both substantially crescent-shaped, and the recess in the substantially crescent-shaped shape is provided. It arrange | positions so that it may mutually oppose and a mutual edge part may oppose.
The housing-side high-pressure generating groove is provided in two port-facing regions, which are regions where the end of the housing-side suction port and the end of the housing-side discharge port face each other, It is provided so as to be tapered toward the end of the housing side suction port facing from the end of the discharge port.
The plate-side high-pressure generating groove is provided at a position facing the housing-side high-pressure generating groove in the pump plate, and the end of the plate-side suction port facing from the end of the plate-side discharge port. It is provided so as to be tapered toward the part.

According to the third aspect of the invention, the housing-side high-pressure generating groove and the plate-side high-pressure generating groove are provided at the location where the fluid leakage is estimated to be the largest and the location where the leakage is estimated to be the next highest. Provide.
Thereby, the amount of fluid leakage from the housing side discharge port and the plate side discharge port can be efficiently suppressed.

It is a perspective view explaining the structure of one embodiment of the internal gear pump 1. (A) is the figure which looked at the pump plate 40 of FIG. 1 from the housing 30 side, (B) is the figure which looked at the inner gear 10 and the outer gear 20 of FIG. 1 from the pump plate 40 side, (C) FIG. 2 is a view of the housing 30 of FIG. 1 as viewed from the pump plate 40 side. It is a figure explaining the other example of the shape of the groove | channel for housing side high pressure generation | occurrence | production, and the groove | channel for plate side high pressure generation | occurrence | production. It is a figure explaining the other example of the shape of the groove | channel for housing side high pressure generation | occurrence | production, and the groove | channel for plate side high pressure generation | occurrence | production. It is a figure explaining the example which provided the groove | channel 38 for the housing side high voltage | pressure generation | occurrence | production in the circumference | surroundings of the discharge port 31B entirely, and provided the groove | channel 48 for the plate side high voltage | pressure generation | occurrence | production in the circumference | surroundings of the discharge port 41B.

EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing.
● [Overall structure of internal gear pump 1 (Figs. 1 and 2)]
First, the structure of the internal gear pump 1 will be described with reference to the perspective view of FIG.
The internal gear pump 1 includes an inner gear 10, an outer gear 20, a housing 30 (corresponding to a pump housing), a pump plate 40, and a drive shaft unit 50.
The inner gear 10 is housed in the housing space 20K of the outer gear 20.
The housing 30 has a housing recess opening at one end, and the gear receiving space 30K is formed by attaching the pump plate 40 to one end of the housing 30 and closing the housing recess. The inner gear 10 and the outer gear 20 are housed in the gear housing space 30K.
Further, the shaft member 51 that can rotate around the rotation axis Zi in the drive shaft unit 50 is inserted into the through hole 32 formed in the bottom portion of the housing recess in the housing 30 and the shaft hole 12 formed in the inner gear 10, and passes through the inner gear 10. Rotation drive. The rotation axis Zi is a rotation axis Zi of the inner gear 10 described later. Reference numeral 52 denotes a seal member.
2A is a view of the pump plate 40 shown in FIG. 1 viewed from the housing 30 side, and FIG. 2B is a view of the outer gear 20 and the inner gear 10 shown in FIG. 1 viewed from the pump plate 40 side. 2C is a view of the housing 30 shown in FIG. 1 as viewed from the pump plate 40 side.

The inner gear 10 has a plurality of external teeth T11 meshing with the internal teeth T21 of the outer gear 20 on the outer peripheral surface, and in the present embodiment, an example in which the number of teeth is 7 is shown.
The outer gear 20 has an accommodation space 20K that can accommodate the inner gear 10, and a plurality of internal teeth T21 that mesh with the external teeth T11 of the inner gear 10 are formed on the inner peripheral surface of the outer gear 20 that forms the accommodation space 20K. In this embodiment, an example in which the number of teeth is 8 is shown.
Further, as shown in FIG. 2B, the rotation axis Zo of the outer gear 20 and the rotation axis Zi of the inner gear 10 are at different positions. Thus, when the inner gear 10 rotates about the rotation axis Zi, the outer gear 20 rotates about the rotation axis Zo, and the volume of the closed space 22 formed between the outer teeth T11 of the inner gear 10 and the inner teeth T21 of the outer gear 20 is increased. After gradually increasing, it gradually decreases. A fluid suction port 41 is provided on the side where the volume gradually increases, and a fluid discharge port 42 is provided on the side where the volume gradually decreases (see FIG. 2A). ). The minimum closed space 22Min having the smallest volume in the closed space 22 is a closed space formed at a position in the direction from the rotation axis Zo to the rotation axis Zi. The largest closed space 22Max having the largest volume in the closed space 22 is A closed space formed at a position in the direction from the rotation axis Zi to the rotation axis Zo.
In the present embodiment, an example in which the suction port 41 and the discharge port 42 are provided in the pump plate 40 will be described.

As shown in FIG. 1 and FIGS. 2A and 2C, in the gear housing space 30K that is a space that can accommodate the outer gear 20 and the inner gear 10 and is a space formed by the pump plate 40 and the housing 30. A substantially crescent-shaped suction port 41A (corresponding to a plate-side suction port) is formed in a concave shape on the surface of the pump plate 40 facing the housing 30 so as to extend in the circumferential direction continuously to the suction port 41. Yes. On the surface of the housing 30 facing the suction port 41A of the pump plate 40, a substantially crescent-shaped suction port 31A (corresponding to the housing side suction port) having the same shape as the suction port 41A is formed in a concave shape.
Similarly, in the gear housing space 30K, a substantially crescent-shaped discharge port 41B (plate-side discharge port) is formed on the surface of the pump plate 40 on the side facing the housing 30 so as to extend in the circumferential direction continuously to the discharge port 42. Is equivalent to a concave shape. On the surface of the housing 30 facing the discharge port 41B of the pump plate 40, a substantially crescent-shaped discharge port 31B (corresponding to the housing-side discharge port) having the same shape as the discharge port 41B is formed in a concave shape.

As shown in FIG. 2 (A), in the pump plate 40, the substantially crescent-shaped intake port 41A and the discharge port 41B are arranged so that the concave portions in the substantially crescent shape are opposed to each other and the end portions 41AA and 41BA are opposed to each other. , And the end portion 41AB and the end portion 41BB are arranged so as to face each other.
As shown in FIG. 2C, in the housing 30, the substantially crescent-shaped intake port 31A and the discharge port 31B are arranged so that the concave portions in the substantially crescent shape are opposed to each other and the end portions 31AA and 31BA, And the end portion 31AB and the end portion 31BB are arranged so as to face each other.
As shown in FIG. 2C, the housing 30 is formed with a through hole 32 for inserting the shaft member 51.

When the inner gear 10 and the outer gear 20 rotate in the gear rotation direction shown in FIGS. 2A to 2C, the fluid sucked from the suction port 41 is filled in the suction port 41A, and the inner gear 10 and the outer gear 20 The closed space 22 is filled, and the suction port 31A is also filled.
The fluid held in the closed space 22 is carried along with the rotation of the inner gear 10 and the outer gear 20, filled in the discharge ports 41 </ b> B and 31 </ b> B, pushed out from the discharge port 42 with high pressure, and discharged.
The fluid to be discharged has a high pressure, and some fluid may not be discharged from the discharge port 42 but may leak from the periphery of the discharge port 31B and the discharge port 41B. The efficiency of the pump capacity is reduced by the amount of fluid leakage from the discharge port. In the present application, the amount of fluid leakage is suppressed, and the efficiency of the pump capacity is further improved.
Hereinafter, a structure for suppressing the fluid leakage will be described.

[Housing side high pressure generating grooves 34A, 34B and plate side high pressure generating grooves 44A, 44B (FIGS. 1 and 2)]
In order to suppress the amount of fluid leakage from the discharge port 31B and the discharge port 41B, the gap between the housing 30, the inner gear 10 and the outer gear 20, and the gap between the pump plate 40, the inner gear 10 and the outer gear 20, are provided. A method of making it smaller is also conceivable. However, if this gap is reduced, the resistance when the inner gear 10 and the outer gear 20 are rotationally driven increases, and the driving force of the drive shaft unit 50 must be increased. Therefore, there is a possibility that it cannot contribute to the improvement of the efficiency of the pumping capacity. There is.
Therefore, as described below, a leaked fluid is used, and a high-pressure portion is formed in the gap by the flow of the leaked fluid, thereby suppressing the amount of leakage.

As shown in FIGS. 1 and 2A, 2C, at least a part of the periphery of the discharge port 31B in the housing 30 is tapered toward the direction of leakage of the fluid leaking from the discharge port 31B. Side high pressure generating grooves 34A and 34B are provided.
Further, plate-side high-pressure generating grooves 44A, 44B that are tapered toward the leakage direction of the fluid leaked from the discharge port 41B are provided at positions facing the housing-side high-pressure generating grooves 34A, 34B in the pump plate 40. It has been.

In the example shown in FIG. 2C, the leaked fluid flows in the port facing region M30B, which is a region where the end portion 31AB of the suction port 31A of the housing 30 and the end portion 31BB of the discharge port 31B face each other. The example which provided the groove | channel 34B for the housing side high voltage | pressure generation | occurrence | production which tapers toward the direction which goes to end part 31AB from a certain end part 31BB is shown. In addition, the port facing region M30A, which is a region where the end portion 31AA of the suction port 31A of the housing 30 and the end portion 31BA of the discharge port 31B face each other, is also connected to the end portion 31BA that is the direction in which the leaked fluid flows. An example is shown in which a housing-side high-pressure generating groove 34A that tapers in a direction toward 31AA is provided.
In the example shown in FIG. 2A, the position of the pump plate 40 (port facing region M40B) facing the housing side high pressure generating groove 34B is changed from the end 41BB, which is the direction in which the leaked fluid flows, to the end 41AB. The example which provided the groove | channel 44B for plate side high voltage | pressure generation | occurrence | production tapering toward the direction to go is shown. Further, a plate that tapers in the direction from the end 41BA toward the end 41AA, which is the direction in which the leaked fluid flows, at the position of the pump plate 40 (port facing region M40A) facing the housing side high pressure generating groove 34A. An example in which a side high pressure generating groove 44A is provided is shown.

The port facing area M30B is an area of a path that is estimated to have the largest amount of fluid leakage from the discharge port 31B, and the port facing area M30A is a path that is estimated to have the next largest amount of fluid leakage from the discharge port 31B. It is an area.
Similarly, the port facing area M40B is an area of a path that is estimated to have the largest amount of fluid leakage from the discharge port 41B, and the port facing area M40A is estimated to have the next largest amount of fluid leakage from the discharge port 41B. This is the area of the route to be performed.
The port facing areas M30A, M30B, M40A, and M40B are close to the discharge port filled with the relatively high pressure fluid and the suction port filled with the relatively low pressure fluid, so that the other areas It is estimated that the amount of fluid leakage is greater than In the port facing regions M30B and M40B, the flow direction of the leaked fluid and the pump rotation direction are the same direction, so it is estimated that the flow rate of the leaked fluid is the highest.

Since the housing side high pressure generating grooves 34A and 34B and the plate side high pressure generating grooves 44A and 44B have a tapered shape, the flow of the leaked fluid is concentrated at the tip of each groove to form a high pressure portion. . By this high-pressure part, the flow of the leaked fluid can be suppressed, and the amount of fluid leakage can be reduced. Thereby, the efficiency of pump capacity can be improved more.
Further, by providing the plate-side high-pressure generating grooves 44A and 44B at positions facing the housing-side high-pressure generating grooves 34A and 34B, respectively, the front surface (the pump plate side) and the back surface (back side) of the inner gear 10 and the outer gear 20 The gap between the pump plate 40 and the inner gear 10 and the outer gear 20 (and the gap between the housing 30 and the inner gear 10 and the outer gear 20) is increased by canceling out the high pressure generated on the housing side. To prevent that. Further, the inner gear 10 and the outer gear 20 are prevented from tilting toward the pump plate 40 or the housing 30, and the inner gear 10 and the outer gear 20 are brought into contact with the pump plate 40 or the housing 30 to increase wear. Can be prevented.

In the above description, the housing side high pressure generating grooves 34A and 34B are provided in the two port facing regions M30A and M30B in the housing 30, respectively, and the two plate facing regions M40A and M40B in the pump plate 40 are in the plate side. The example in which the high pressure generating grooves 44A and 44B are provided has been described. In this case, it is possible to efficiently suppress fluid leakage in the port facing regions M30B and M40B where the amount of fluid leakage is estimated to be the largest, and in the port facing regions M30A and M40A where the amount of leakage is estimated to be the next largest. .
Of the two port facing regions M30A and M30B in the housing 30, the port in which the direction from the end of the discharge port 31B toward the end of the suction port 31A facing the same direction as the rotation direction of the inner gear 10 is the same. The housing side high pressure generating groove 34B may be provided on the facing region M30B side, and the housing side high pressure generating groove 34A may be omitted. In this case, the plate side high pressure generating groove 44B is provided on the side of the port facing region M40B among the two port facing regions M40A and M40B in the pump plate 40, and the plate side high pressure generating groove 44A is omitted. In this case, it is possible to efficiently suppress fluid leakage in the port facing regions M30B and M40B that are estimated to have the largest amount of fluid leakage.
In each of the housing-side high-pressure generating groove and the plate-side high-pressure generating groove, the width of the groove, the depth of the groove, the length of the groove, and the number of grooves are not particularly limited, but the housing 30 and the pump plate 40 In each case, grooves of the same shape and the same size are arranged in the same number and facing each other in the same direction.

● [Other examples of the shape of the housing side high pressure generating groove and the shape of the plate side high pressure generating groove (FIGS. 3 and 4)]
Next, another shape of the housing-side high-pressure generating grooves 34A and 34B and the plate-side high-pressure generating grooves 44A and 44B shown in FIG. 2 will be described with reference to FIGS. The positions where the housing side high pressure generating grooves and the plate side high pressure generating grooves are provided (port facing regions M30A, M30B, M40A, M40B) are the same positions.
The shape of the housing-side high-pressure generating grooves 34A and 34B and the plate-side high-pressure generating grooves 44A and 44B shown in FIGS. 2A and 2C is a “he” -shaped shape. The vertices of the letter are oriented in the direction toward the end portions 31AA and 31AB of the suction port 31A and the end portions 41AA and 41AB of the suction port 41A.

In contrast, in the example shown in FIGS. 3A and 3B, the housing-side high-pressure generating grooves 35A and 35B and the plate-side high-pressure generating grooves 45A and 45B have a “C” shape. The upper opening of the letter “C” is directed toward the ends 31AA and 31AB of the suction port 31A and the ends 41AA and 41AB of the suction port 41A.
4A and 4B, the housing-side high-pressure generating grooves 36A and 36B and the plate-side high-pressure generating grooves 46A and 46B are triangular in shape, and the apex of the triangle is It is directed in the direction toward the end portions 31AA and 31AB of the suction port 31A and the end portions 41AA and 41AB of the suction port 41A.
As described above, the shape of the housing-side high-pressure generating groove and the shape of the plate-side high-pressure generating groove may be any shape as long as they are tapered toward the direction of fluid leakage.

● [Other examples of positions where the housing side high pressure generating groove and the plate side high pressure generating groove are provided (FIG. 5)]
In the above description, the housing side high pressure generating groove and the plate side high pressure generating groove are provided in the port facing regions M30A, M30B, M40A, M40B, or in the port facing regions M30B, M40B. The housing side high pressure generating groove 38 and the plate side high pressure generating groove 48 may be provided in the regions M30C and M40C shown in FIG.

A region M40C shown in FIG. 5A is a region that covers the entire discharge port 41B in the pump plate 40, a region that avoids the discharge port 42, and a region that avoids the position facing the through hole 32. is there.
Further, a region M30C shown in FIG. 5B is a region that covers the entire discharge port 31B in the housing 30, is a region that avoids a position facing the discharge port 42, and a region that avoids the through hole 32. It is.
The fluid leaking from the discharge port 41B may leak from any position of the discharge port 41B, and the fluid leaking from the discharge port 31B may leak from any position of the discharge port 31B.

In each of the housing-side high-pressure generating groove 38 and the plate-side high-pressure generating groove 48, the groove width, groove depth, groove length, and number of grooves are not particularly limited, but the housing 30C, pump plate In each of 40C, the same number of grooves having the same shape and the same size are arranged to face each other in the same direction. Moreover, each groove | channel is provided so that it may become a taper shape toward the direction where the leaked fluid flows.
In the example shown in FIGS. 5A and 5B, the leakage amount can be suppressed against leakage in any direction of fluid from the discharge ports 31 </ b> B and 41 </ b> B.

As described above, the housing-side high-pressure generating groove and the plate-side high-pressure generating groove described in the present embodiment use the flow of the leaked fluid to form a high-pressure portion at the leaked portion and suppress the leakage amount. Further, the efficiency of the pump capacity can be further improved, and further reduction in size and weight can be promoted.
Further, by providing the housing-side high-pressure generating groove and the plate-side high-pressure generating groove at opposing positions, it is possible to prevent the inner gear 10 and the outer gear 20 from coming into contact with the housing or the pump plate and increasing wear.

The internal gear pump 1 of the present invention is not limited to the appearance, configuration, structure, and the like described in the present embodiment, and various modifications, additions, and deletions are possible without departing from the scope of the present invention.
In the internal gear pump 1 of the present invention, the number of teeth of the outer gear and the inner gear is not limited to the number of teeth described in the present embodiment, and can be applied to the outer gear and the inner gear having various numbers of teeth.
The internal gear pump 1 of the present invention can be used as various oil pumps used for vehicles, for example, and can be used as various mechanical pumps for sucking and discharging various fluids.

DESCRIPTION OF SYMBOLS 1 Internal gear pump 10 Inner gear 20 Outer gear 20K Housing space 30, 30A, 30B, 30C Housing (pump housing)
30K Gear accommodating space 31A, 41A Suction port 31AA, 31AB, 41AA, 41AB (Suction port) end 31B, 41B Discharge port 31BB, 31BA, 41BA, 41BB (Discharge port) end 32 Through hole 34A, 34B, 35A , 35B, 36A, 36B, 38 Housing side high pressure generating groove 40, 40A, 40B, 40C Pump plate 41 Suction port 42 Discharge port 44A, 44B, 45A, 45B, 46A, 46B, 48 Plate side high pressure generating groove 50 Drive Shaft unit 51 Shaft member M30A, M30B, M40A, M40B Port facing area M30C, M40C area T11 External teeth T21 Internal teeth Zi Inner gear rotation axis Zo Outer gear rotation axis

Claims (3)

A pump housing having a housing recess opening on one end side;
A pump plate which is attached to one end of the pump housing and forms a gear housing space by closing the housing recess;
An outer gear housed rotatably in the gear housing space and having internal teeth on the inner peripheral surface;
An inner gear having outer teeth on the outer peripheral surface that mesh with the inner teeth of the outer gear;
A shaft member that is inserted into a through hole formed in a bottom portion of the housing recess of the pump housing and is fitted in a shaft hole of the inner gear so as to rotate the inner gear,
A concave housing side suction port and a concave housing side discharge port are formed on a surface of the pump housing that forms the gear receiving space and faces the pump plate,
A concave plate side suction port having the same shape as the housing side suction port is formed at a position facing the housing side suction port on the pump plate, and a position facing the housing side discharge port is formed on the pump plate. In the internal gear pump in which a concave plate side discharge port having the same shape as the housing side discharge port is formed,
At least part of the periphery of the housing-side discharge port in the pump housing is provided with a housing-side high-pressure generating groove that tapers in the leakage direction of the fluid leaking from the housing-side discharge port.
A plate-side high-pressure generating groove that is tapered toward the leakage direction of the fluid leaking from the plate-side discharge port is provided at a position facing the housing-side high-pressure generating groove in the pump plate.
Inscribed gear pump. The internal gear pump according to claim 1,
Each of the housing side suction port and the housing side discharge port has a substantially crescent shape, and is disposed so that the concave portions in the substantially crescent shape are opposed to each other and the end portions are opposed to each other.
Each of the plate-side suction port and the plate-side discharge port has a substantially crescent shape, and is disposed such that the recesses in the substantially crescent shape are opposed to each other and the end portions thereof are opposed to each other.
The housing-side high-pressure generating groove is a region of the housing-side discharge port among the two port-facing regions in which the end of the housing-side suction port and the end of the housing-side discharge port are opposed to each other. A direction from the end toward the end of the housing-side intake port is provided in a port-facing region on the side where the direction of rotation of the inner gear is the same as that of the inner gear. Is provided to be tapered toward the end of the housing side suction port.
The plate-side high-pressure generating groove is provided at a position facing the housing-side high-pressure generating groove in the pump plate, and is formed at the end of the plate-side suction port facing from the end of the plate-side discharge port. It is provided to be tapered toward the
Inscribed gear pump. The internal gear pump according to claim 1,
Each of the housing side suction port and the housing side discharge port has a substantially crescent shape, and is disposed so that the concave portions in the substantially crescent shape are opposed to each other and the end portions are opposed to each other.
Each of the plate-side suction port and the plate-side discharge port has a substantially crescent shape, and is disposed such that the recesses in the substantially crescent shape are opposed to each other and the end portions thereof are opposed to each other.
The housing-side high-pressure generating groove is provided in two port-facing regions, which are regions where the end of the housing-side suction port and the end of the housing-side discharge port face each other, and the housing-side discharge port Is provided so as to taper toward the end of the housing-side suction port facing from the end of the housing,
The plate-side high-pressure generating groove is provided at a position facing the housing-side high-pressure generating groove in the pump plate, and is formed at the end of the plate-side suction port facing from the end of the plate-side discharge port. It is provided to be tapered toward the
Inscribed gear pump.

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