JP2006046273A - Internal gear pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal gear pump, in which sliding resistance between an outer rotor and a seal member is eliminated to improve energy efficiency, and in which possibility of abrasion damage in a seal means is avoided. <P>SOLUTION: This internal gear pump is provided with the outer rotor rotatably contained in a housing member, having an internal gear on the inner circumferential side, the inner rotor rotatably provided on the inner circumferential side of the outer rotor, having an external gear to be engaged with the internal gear on the outer circumferential side, a drive shaft connected to the inner rotor to be driven to rotate, and an intermediate ring provided between the outer rotor and the housing member to be relatively movable to the housing member, in such a way that the outer rotor is relatively rotatable. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotary pump that sucks and discharges fluid.

  Conventionally, in an internal gear pump, among a plurality of pump chambers formed between an outer rotor having an internal gear and an inner rotor having an external gear, a confining portion having a maximum volume is sandwiched. The pump chamber on one side communicates with the suction passage, and the pump chamber on the other side communicates with the discharge passage. In the discharge side pump chamber, the pump discharge pressure acts in a direction in which the outer rotor is separated from the inner rotor. Therefore, there is a problem that an engagement gap is excessively generated between the internal gear of the outer rotor and the external gear of the inner rotor, and oil leakage occurs.

In order to solve this problem, for example, in the internal gear pump disclosed in Patent Document 1, by introducing discharge pressure to the outer periphery of the discharge-side outer rotor and introducing suction pressure to the outer periphery of the suction-side outer rotor, The outer rotor is pressed against the inner rotor side to reduce the meshing gap between the internal gear and the external gear. A seal member is provided on the inner peripheral wall surface of the housing to seal the high pressure side (discharge side) and the low pressure side (suction side).
Japanese Patent Application Laid-Open No. 11-117876

  However, in the above prior art, since the seal member is always in sliding contact with the outer rotor, there is a problem in that it causes sliding resistance when the pump is driven, energy efficiency is deteriorated, and wear damage of the sealing means may occur. there were.

  The present invention has been made paying attention to the above-mentioned problems, and its object is to eliminate the sliding resistance between the outer rotor and the seal member, to improve energy efficiency and to avoid the possibility of wear damage of the sealing means. An internal gear pump is provided.

  In order to achieve the above object, in the present invention, a housing member, an outer rotor that is rotatably accommodated inside the housing member, and has an internal gear on the inner peripheral side, and a rotatable member provided on the inner peripheral side of the outer rotor, An inner rotor having an external gear that meshes with the internal gear on the outer peripheral side, a drive shaft that is connected to the inner rotor and rotationally drives the inner rotor, an internal gear of the outer rotor, and an external gear of the inner rotor Among the plurality of pump chambers, a suction port that opens to a suction region in which the volume of the pump chamber increases with the rotation of the drive shaft, and among the plurality of pump chambers, with the rotation of the drive shaft, A discharge port that opens to a discharge region in which the volume of the pump chamber decreases, and between the outer rotor and the housing member, with respect to the housing member Said outer rotor has a to and an intermediate ring provided so as to be rotatable relative.

  Therefore, by providing an intermediate ring between the housing and the outer rotor, an internal gear pump that eliminates the sliding resistance between the outer rotor and the seal member, improves energy efficiency, and avoids the possibility of wear damage of the seal means. Can be provided.

  Hereinafter, the best mode for realizing the internal gear pump of the present invention will be described based on Example 1 and Example 2 shown in the drawings.

[Configuration of internal gear pump]
Example 1 will be described with reference to FIGS. FIG. 1 is an axial sectional view of the internal gear pump 1, and FIG. 2 is a front view of the cam ring 110 and the first housing 120 viewed from the axial direction. In the cross-sectional view of FIG. 1, the cross section on the first housing 120 side is shown, and in FIGS. 1 and 2, the normal direction of the drawing is the z-axis.

  The internal gear pump 1 is a so-called bidirectional pump, and includes a housing 10, an outer rotor 20, an inner rotor 30, an intermediate ring 40, and a drive shaft 50. The housing 10 includes a cam ring 110 that is an annular member, and first and second housings 120 and 130 that sandwich the cam ring 110 from both ends in the axial direction.

  The cam ring 110 in the housing 10 houses the outer rotor 20, the inner rotor 30, and the intermediate ring 40 inside the ring. In addition, a first suction port 122 is provided in the region of the positive z-axis surface 121 of the first housing 120 in the negative x-axis direction from the line I-II in the drawing, and the first suction port 122 is provided in the positive x-axis region. One discharge port 123 is provided.

  The first suction port 122 and the first discharge port 123 are provided in a crescent shape at positions corresponding to the internal gear 210 provided on the outer rotor 20 and the external gear 310 provided on the inner rotor 30. In the vicinity of the straight line I-II. Further, a drain 111 is provided on the circumference of the cam ring 110 on the straight line I-II. Although not shown in FIG. 1, the second housing 130 is also provided with a crescent-shaped second suction port 132 and a second discharge port 133 at positions corresponding to the internal gear 210 and the external gear 310, and is a straight line I-II. Blocks in the vicinity.

  The outer rotor 20 has an internal gear 210 on the inner periphery, and is rotatably mounted on the cam ring 110 on the outer surface 220 of the outer rotor. An inner rotor 30 having an external gear 310 is accommodated on the inner periphery of the outer rotor 20. The internal gear 210 and the external gear 310 are provided at the same pitch, and the number of teeth of the internal gear 210 is one more than the number of teeth of the external gear 310. The difference between the number of teeth of the internal gear 210 and the number of teeth of the external gear 310 may be two or more, and is not particularly limited.

  The internal gear 210 and the external gear 310 are arranged so as to mesh with each other at the time of installation. However, since the number of teeth of the internal gear 210 is one more than the number of teeth of the external gear 310, When the tooth gears 310 are engaged, they are engaged with each other eccentrically. Therefore, the shaft center of the external gear 310, that is, the axis O ′ of the inner rotor 30, is eccentric with respect to the axis center of the internal gear 210, that is, the outer rotor 20, by the distance e in the positive direction of the y-axis. A pump chamber 600 separated by the internal gear 210 and the external gear 310 is formed.

  Due to the eccentricity of the outer rotor 20 and the inner rotor 30, the internal gear 210 and the external gear 310 mesh closely with each other toward the positive y-axis direction, and completely mesh with each other at the end A in the positive y-axis direction. The meshing is disengaged in the negative y-axis direction, and the meshing is completely disengaged at the end B in the y-axis negative direction.

  That is, when the inner rotor 30 and the outer rotor 20 are rotated counterclockwise, the x-axis negative direction side region (corresponding to the first and second suction ports 122 and 132) with respect to the I-II straight line in the pump chamber 600 is rotated to increase the volume. Increases in the suction region 610, and in the x-axis positive direction side region (corresponding to the first and second discharge ports 123 and 133), the discharge region 620 decreases in volume with rotation.

  Furthermore, when fully engaged at the y-axis positive direction end A, the peaks 211 and 311 of the crests of the internal gear 210 and the external gear 310 are aligned on the same straight line at the y-axis negative direction end B. In addition, the clearance between the vertices 211 and 311 is provided to be substantially zero while avoiding contact.

  The intermediate ring 40 is an annular member like the cam ring 110 and is provided between the cam ring inner peripheral surface 112 and the outer rotor outer peripheral surface 220. A region defined by the cam ring inner peripheral surface 112 and the outer rotor outer peripheral surface 220 communicates with the drain 111 as a drain oil passage 150.

  A portion of the drain oil passage 150 on the positive side in the x-axis direction with respect to the straight line I-II in the drawing is circumferentially formed by first and second sealing materials 160 and 170 formed of Teflon (registered trademark) resin or the like. Divided into three. Further, first and second leaf springs 162 and 172 are provided on the outer circumferences of the first and second sealing materials 160 and 170 to urge the first and second sealing materials 160 and 170 in the inner diameter direction.

  The first seal portion 151 sandwiched between the first and second seal materials 160 and 170 is communicated with the discharge region 620 of the pump chamber 600 through the first connection passage 125 provided in the first housing 120. The circumferential intermediate position a of the first seal portion 151 is biased toward the y-axis negative direction end B side with respect to the circumferential intermediate position b between the y-axis positive direction end A and the y-axis negative direction end B. Is provided.

  The internal gear pump 1 which is a bi-directional pump is symmetrical with respect to the I-II straight line, and the third and fourth parts made of Teflon (registered trademark) resin or the like are similarly formed on the x-axis negative direction side portion. The third and fourth sealing members 180 and 190 are divided into three in the circumferential direction, and third and fourth leaf springs 182 and 192 are provided on the outer periphery of the third and fourth sealing members 180 and 190, respectively. 190 is urged in the inner diameter direction.

  The second seal portion 152 sandwiched between the third and fourth seal members 180 and 190 is communicated with the suction region 610 of the pump chamber 600 through the second connection passage 126 provided in the first housing 120, and the second seal portion. The intermediate position a ′ in the circumferential direction 152 is offset from the intermediate position b ′ in the y-axis positive direction end A and the y-axis negative direction end B on the y-axis negative direction end B side. .

  A drive shaft 50 provided parallel to the z-axis rotates integrally with the inner rotor 30 and is connected to a drive source (not shown) to drive the inner rotor 30. Since the inner rotor 30 and the outer rotor 20 mesh with each other, the inner rotor 30 and the outer rotor 20 are rotationally driven as the drive shaft 50 rotates. The internal gear pump 1 functions as a bidirectional pump when the drive shaft 50 rotates forward and backward.

[Details of housing]
FIG. 2 is an axial front view of the cam ring 110 and the first housing 120 in the housing 10. As described above, the first and second suction ports 122 and 132 and the first and second discharge ports provided on the z-axis positive direction surface 121 of the first housing 120 and the y-axis negative direction surface 131 of the second housing 131. 123 and 133 are provided at positions corresponding to the internal gear 210 provided on the outer rotor 20 and the external gear 310 provided on the inner rotor 30, and close in the vicinity of the I-II straight line. The radial width of each suction and discharge port is provided so as to increase toward the negative y-axis direction.

  Further, first to fourth seal material fitting portions 161 to 191 for fitting the first to fourth seal materials 160 to 190 and the first to fourth seal material fitting portions 162 to 192 are provided. The circumferential intermediate positions a and a ′ of the fourth sealing material fitting portions 161 to 191 are more in the y-axis than the circumferential intermediate positions b and b ′ between the y-axis positive direction end A and the y-axis negative direction end B. It is biased to the negative end B side.

[IV-V cross section]
3 is a cross-sectional view of the internal gear pump 1 in the IV-V cross section of FIG. 1, and FIG. 4 is a cross-sectional view of the housing 10 in the IV-V cross section of FIG. The first and second housings 120 and 130 are provided with first and second suction ports 122 and 132 and first and second discharge ports 123 and 133, respectively. First and second connection passages 125 and 126 are provided on the outer periphery of the first discharge port 123.

  The first connection passage 125 communicates the discharge region 620 of the pump chamber 600 with the first seal portion 151 of the drain oil passage 150 via the first discharge port 123, and the second connection passage 126 passes through the first suction port 122. The suction region 610 of the pump chamber 600 and the second seal portion 152 of the drain oil passage 150 are communicated.

[I-III cross section]
5 is a cross-sectional view of the internal gear pump 1 in the I-III cross section of FIG. 1, and FIG. 6 is a cross-sectional view of the housing 10 in the I-III cross section of FIG. The drain 111 is a radial groove provided on the I-II straight line of the cam ring 110 that is an annular member, and functions as a discharge port for oil leaked between the cam ring inner peripheral surface 112 of the housing 10 and the intermediate ring 40. Then, the oil leaked to the non-seal part 153 is positively introduced into the drain 111, and the pressure of the non-seal part 153 is reduced.

  In addition, the first leaf spring 162 and the first seal material 160 are fitted into the first seal material fitting portion 161 of the cam ring 110 in order from the outer diameter direction, and the first seal material is intermediated by the urging force of the first plate spring 162. Sealing is performed by contacting the ring outer peripheral surface 410.

[Internal gear pump drive action]
FIG. 7 is a diagram showing a pressure load generated in the internal gear pump 1 during driving. During driving, first, the drive shaft 50 rotates counterclockwise, and the inner rotor 30 and the outer rotor 20 rotate counterclockwise accordingly. Since the intermediate ring 40 is interposed between the outer rotor 20 and the cam ring 110, the sliding surface of the outer rotor 20 that rotates as the pump is driven becomes the intermediate ring inner peripheral surface 420. Further, the first to fourth seal members 160 to 190 are urged against and contacted with the outer peripheral surface 410 of the intermediate ring by the first to fourth leaf springs 162 to 192, and the seal surface becomes the intermediate ring outer peripheral surface 410.

  Along with the left rotation of the inner rotor 30 and the outer rotor 20, the pump volume increases in the suction region 610 in the pump chamber 600, and a negative pressure p is generated. On the other hand, in the discharge region 620, the pump volume is reduced and the pressure is increased.

  Oil is sucked into the suction area 610 from the first and second suction ports 122 and 132 by this negative pressure p, and sequentially by the teeth of the external gear 310 and the internal gear 210 that rotate as the inner rotor 30 and the outer rotor 20 rotate. It moves counterclockwise and is introduced into the discharge area 620. In the discharge region 620, the oil is increased to the discharge pressure p * and discharged from the first and second discharge ports 123 and 133.

  Oil is also introduced into the first connection passage 125 that communicates with the discharge region 620, and oil at the discharge pressure p * is also introduced into the first seal portion 151 in the drain oil passage 150. In addition, oil of negative pressure p is introduced into the second seal portion 152 through the second connection passage 126 that communicates with the suction region 610. Further, the oil leaked along the axial end surfaces of the outer rotor 20 and the intermediate ring 40 is supplied to the drain oil passage 150.

  Here, the oil of negative pressure p is introduced into the second seal portion 152, and the leaked oil is introduced into the non-seal portion 153 of the drain oil passage 150. The hydraulic pressure at the seal portion 153 is lower than the discharge pressure p * at the first seal portion 151. Further, the intermediate position “a” of the first seal portion 151 is biased toward the end B of the y-axis negative direction.

  Further, the hydraulic pressure in the discharge region 620 is the discharge pressure p *, and in the discharge region 620, a force F3 acts in a direction in which the outer rotor 20 is separated from the inner rotor 30. By this force F3, the outer rotor 20 is urged from the suction side to the discharge side, that is, the x-axis positive direction, and the intermediate ring 40 that slides while the outer rotor 20 rotates is also urged in the x-axis positive direction.

  Therefore, F1 acts on the intermediate ring 40 in the negative x-axis direction, F3 acts in the positive x-axis direction, and F2 force acts in the positive y-axis direction. As a result, the intermediate ring 40 is urged in the y-axis positive direction as the internal gear pump 1 is driven, and the outer rotor 20 sliding with the intermediate ring 40 is also urged in the y-axis positive direction. At the end B, the clearance between the vertex 211 of the internal gear 210 and the vertex 311 of the external gear 310 is reduced.

  Although the drive shaft 50 is rotated counterclockwise in the first embodiment, the internal gear pump 1 of the present application is a bidirectional pump, and even if the drive shaft 50 is rotated clockwise, only the suction side and the discharge side in the first embodiment are reversed. The other operations are the same as in the first embodiment. That is, the second seal portion 152 communicating with the second connection passage 126 becomes high pressure to urge the intermediate ring 40 in the x-axis positive direction and the y-axis positive direction, and the x-axis with respect to the I-II straight line in the pump chamber 600. A portion on the negative direction side (the suction region 610 in the first embodiment) becomes a high pressure, and biases the intermediate ring 40 in the negative x-axis direction.

[Contrast of effects of conventional example and first embodiment]
Conventionally, in an internal gear pump, among a plurality of pump chambers formed between an outer rotor having an internal gear and an inner rotor having an external gear, a confining portion having a maximum volume is sandwiched. The pump chamber on one side communicates with the suction passage, and the pump chamber on the other side communicates with the discharge passage. By introducing discharge pressure to the outer periphery of the discharge-side outer rotor and introducing suction pressure to the outer periphery of the suction-side outer rotor, the outer rotor is pressed against the inner rotor side, and the meshing gap between the internal gear and the external gear is reduced. It is decreasing. A seal member is provided on the inner peripheral wall surface of the housing to seal the high pressure side (discharge side) and the low pressure side (suction side).

  However, in the above prior art, since the seal member is always in sliding contact with the outer rotor, there is a problem in that it causes sliding resistance when the pump is driven, energy efficiency is deteriorated, and wear damage of the sealing means may occur. there were.

  On the other hand, in the first embodiment of the present application, the intermediate ring 40 is provided between the cam ring 110 and the outer rotor 20, and sealing is performed by the first to fourth seal members 160 to 190 provided between the cam ring 110 and the intermediate ring outer peripheral surface 410. The intermediate ring inner peripheral surface 420 is brought into contact with the outer rotor outer peripheral surface 220 and is slid.

  This makes it possible to separate the sealing surface and sliding surface in the pump drive, eliminating the sliding resistance between the outer rotor and the sealing member, improving energy efficiency, and avoiding the risk of wear damage to the sealing means. A contact gear pump can be provided. In addition, although sliding resistance also arises between the outer rotor 20 and the intermediate ring 40, since sliding oil exists between both, the sliding resistance is very smaller than the sliding resistance in a sealing member. (Corresponding to claim 1).

  In addition, a drain oil passage 150 that is a gap between the cam ring 110 and the intermediate ring 40 is provided, and the first and second sealing materials 160 are disposed on the drain oil passage 150 on the x-axis positive direction side with respect to the I-II straight line. , 170 is divided into three parts, communicated with the first seal part 151 and the discharge region 620 of the pump chamber 600 separated by the first and second seal members 160, 170, from the second seal part 152 and the non-seal part 153. Was also set to high pressure. Furthermore, the intermediate position a of the first seal portion 151 is biased to the y-axis negative direction end B.

  Thereby, in the drain oil passage 150, the intermediate ring 40 is urged in the negative x-axis direction by the force F1, and is urged in the positive y-axis direction by the force F2, and the intermediate ring 40 is urged by the force F3 generated in the discharge region 620. 40 is biased in the positive x-axis direction. Accordingly, as the internal gear pump 1 is driven, the intermediate ring 40 is urged in the y-axis positive direction, and the outer rotor 20 that slides with the intermediate ring 40 is also urged in the y-axis positive direction. The clearance between the vertex 211 of the internal gear 210 and the vertex 311 of the external gear 310 in part B can be reduced.

  Accordingly, it is possible to improve the discharge efficiency of the internal gear pump 1 by avoiding the backflow of oil from the high pressure discharge region 620 to the low pressure suction region 610 in the pump chamber 600 (corresponding to claim 2).

  Further, by separating the seal surface and the sliding surface in the pump drive, even if the outer rotor outer peripheral surface 220 and the intermediate ring inner peripheral surface 420 of the outer ring 20 that is the sliding surface are seized, the seal surface is not affected. Further, the intermediate ring 40 can be slid on the outer peripheral surface 410 of the intermediate ring, and the drive source can be protected.

  A second embodiment will be described with reference to FIGS. Since the basic configuration is the same as that of the first embodiment, only different points will be described. The internal gear pump 1 of the first embodiment is a bidirectional pump, but in the second embodiment, it is a one-way pump. 8 is a cross-sectional view of the one-way internal gear pump 1 according to the second embodiment, and FIG. 9 is an axial front view of the cam ring 110 and the first housing 120.

  Since the internal gear pump 1 of the second embodiment is a one-way pump, the x-axis positive direction side is always the high-pressure side with respect to the I-II straight line, and when the drive shaft 50 is rotated clockwise in the first embodiment, The second seal portion 152 becomes high pressure and urges the intermediate ring 40 in the x-axis positive direction, and the x-axis negative direction side portion (the suction region 610 in the first embodiment) in the pump chamber 600 becomes high pressure and the intermediate ring. The action of urging 40 in the negative x-axis direction is not necessary.

Therefore, in the second embodiment, the second connection passage 126 that connects the suction region 610 and the drain oil passage 150 in the pump chamber 600 is not provided, but only the first connection passage 125 that connects the discharge region 620 is provided. Further, the third and fourth sealing materials 180 and 190 and the third and fourth sealing material fitting portions 181 and 191 are not provided. Even in this case, the first seal portion 151 communicates with the discharge region 620 and inevitably has a higher pressure than other portions in the drain oil passage 150. Therefore, when the internal gear pump 1 is a one-way pump, the same effects as those of the first embodiment can be obtained while reducing the number of parts and the number of processing steps.
(Other examples)

    As described above, the best mode for carrying out the present invention has been described based on the first embodiment. However, the specific configuration of the present invention is not limited to each embodiment and does not depart from the gist of the present invention. Such design changes are included in the present invention.

  In the first and second embodiments, the first to fourth sealing members 160 to 190 formed of Teflon (registered trademark) resin or the like are brought into contact with the outer peripheral surface 410 of the annular intermediate ring. A part of the annular ring may protrude in the outer diameter direction, a part of the inner periphery of the cam ring 110 may be cut out, and a seal may be performed by a mechanical seal that engages the protruding part of the intermediate ring 40 with the cutout of the cam ring 110. .

  Further, technical ideas other than the claims that can be grasped from the respective embodiments will be described below together with the effects thereof.

(A) In the internal gear pump according to claim 1,
The internal gear pump is a bidirectional pump in which the drive shaft rotates forward and reverse, and the suction port and the discharge port are switched.

  Also in the bidirectional pump, the same effect as that of the first aspect can be obtained.

(B) In the internal gear pump according to claim 1,
It further has a low pressure passage for discharging the pressure in a region other than the region sealed between the first sealing unit and the second sealing unit to the low pressure side.

  By actively reducing the pressure in the region other than the region sealed between the first sealing means and the second sealing means, the force acting on the intermediate ring in the direction from the closing portion side to the meshing portion side is increased. growing. Therefore, the meshing property between the outer rotor and the inner rotor in the confining portion is further improved.

(C) In the internal gear pump according to (a),
A third sealing means is further provided symmetrically about an axis connecting the confining portion and the meshing portion of the first sealing means;
A fourth sealing means is further provided symmetrically about an axis connecting the confining portion and the meshing portion of the second sealing means;
A first low pressure passage for discharging the pressure in the region sealed between the first sealing means and the third sealing means to the low pressure side;
And a second low pressure passage for discharging the pressure in the region sealed between the second sealing means and the fourth sealing means to the low pressure side.

  Also in the bi-directional pump, the same effect as the above (b) can be obtained.

(D) In the internal gear pump according to claim 1,
A connecting passage is provided on the outer side in the axial direction of the outer rotor and the intermediate ring, and connects the pump chamber in the discharge region and a region sealed between the first sealing unit and the second sealing unit.

  By actively introducing the pump discharge pressure to the area sealed between the first sealing means and the second sealing means, the force acting on the intermediate ring in the direction from the closing portion side to the meshing portion side is increased. Become. Therefore, the meshing property between the outer rotor and the inner rotor in the confining portion is further improved.

(E) In the internal gear pump according to (a) above,
A first connection passage that is provided on the outer side in the axial direction of the outer rotor and the intermediate ring, and connects a pump chamber of the discharge region and a region sealed between the first seal unit and the second seal unit;
A second connection passage provided on the outer side in the axial direction of the outer rotor and the intermediate ring and connecting a pump chamber of the discharge region and a region sealed between the third seal unit and the fourth seal unit; Have.

  Also in the bi-directional pump, the same effect as the above (d) can be obtained.

(F) In the internal gear pump according to (a) above,
The housing is composed of a cam ring provided on the outer peripheral side of the intermediate ring, and a first housing part and a second housing part provided on both axial sides of the cam ring,
The low-pressure passage is a groove provided on an end surface in the axial direction of the housing.

  Since the low-pressure passage can be formed not as a hole but as a groove provided in the axial end surface of the housing, manufacture (processing) is facilitated.

It is sectional drawing of the bidirectional | two-way internal gear pump in Example 1. FIG. 3 is a radial cross-sectional view of a housing in Embodiment 1. FIG. It is sectional drawing of the internal gear pump in the IV-V cross section of FIG. It is sectional drawing of the housing in the IV-V cross section of FIG. It is sectional drawing of the internal gear pump in the I-III cross section of FIG. It is sectional drawing of the housing in the I-III cross section of FIG. It is a figure which shows the pressure which generate | occur | produces in an internal gear pump at the time of a drive. It is sectional drawing of the one-way internal gear pump in Example 2. FIG. 6 is a radial cross-sectional view of a housing in Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal gear pump 10 Housing 20 Outer rotor 30 Inner rotor 40 Intermediate ring 50 Drive shaft 110 Cam ring 111 Drain 112 Inner ring circumference 120 First housing 121 X-axis positive direction surface 122 First suction port 125 First connection passage 123 First discharge Port 126 Second connection passage 130 Second housing 131 X-axis negative direction surface 140 Inner peripheral surface 150 Drain oil passage 151 First seal portion 152 Second seal portion 153 Non-seal portions 160 to 190 First to fourth seal members 161 to 191 1st-4th sealing material fitting part 162-192 1st-4th leaf | plate spring 210 Internal gear 211 Apex 220 Outer rotor outer peripheral surface 310 External gear 311 Apex 410 Intermediate ring outer peripheral surface 420 Intermediate ring inner peripheral surface 600 Pump Chamber 610 Suction area 620 Discharge area

Claims (2)

A housing member;
An outer rotor housed rotatably in the housing member and having an internal gear on the inner peripheral side;
An inner rotor that is rotatably provided on the inner peripheral side of the outer rotor and has an external gear that meshes with the internal gear on the outer peripheral side;
A drive shaft connected to the inner rotor for driving the inner rotor to rotate;
Among a plurality of pump chambers formed between the internal gear of the outer rotor and the external gear of the inner rotor, a suction port that opens to a suction region where the volume of the pump chamber increases as the drive shaft rotates,
Among the plurality of pump chambers, a discharge port that opens to a discharge region in which the volume of the pump chamber decreases as the drive shaft rotates,
An intermediate ring provided between the outer rotor and the housing member so that the outer rotor is rotatable relative to the housing member;
An internal gear pump characterized by comprising: The internal gear pump according to claim 1,
A first and a second sealing means between the housing member and the intermediate ring in the discharge region and dividing the discharge region into three in the circumferential direction;
The circumferential intermediate position between the first sealing means and the second sealing means is more than the circumferential intermediate position between the meshing portion having the minimum pump volume and the confining portion having the maximum pump volume among the plurality of pump chambers. An internal gear pump characterized in that the internal gear pump is biased toward the closed portion.

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