JP6162434B2 - Oil pump - Google Patents

Description

  The present invention relates to an oil pump that sucks and discharges oil (lubricating oil) of an internal combustion engine (engine) and the like, and particularly includes an inner rotor and an outer rotor of a trochoid type, an internal gear (involute) type or the like. It relates to an oil pump.

  The engine oil pump includes a housing (body), a rotating shaft (shaft) supported by the housing, a first-stage pump unit and a second-stage pump unit arranged in the axial direction of the rotating shaft. The unit is composed of a pair of inner gear and outer gear, the second stage pump unit is composed of a pair of inner gear and outer gear, and the suction port for sucking oil from the outside and discharging the oil to the housing An intermediate outlet for discharging oil from the first stage pump unit, an intermediate inlet for sucking oil into the second stage pump unit, and a partition wall between the first stage pump unit and the second stage pump unit; and A communication path (combined flow path) between the intermediate discharge port and the intermediate suction port is provided, and the first stage inner gear and the second stage via the rotating shaft By rotating the inner gear, rotating the first outer gear in conjunction with the rotation of the first inner gear and rotating the second outer gear in conjunction with the rotation of the second inner gear, Oil is sucked and pressurized from the suction port by the second pump unit, pumped from the intermediate discharge port toward the middle suction port of the second-stage pump unit, and oil is sucked and pressurized from the middle suction port by the second-stage pump unit. A device that discharges from a discharge port is known (see, for example, Patent Document 1).

In this oil pump, the rotational phases of the first-stage pump unit and the second-stage pump unit are shifted by 180 degrees so that the suction of the second-stage pump unit is performed at the time of discharge of the first-stage pump unit. As shown in the figure, the first rotation of the first outer gear O ₁ is positioned at a position deviated by a predetermined distance D with respect to the rotation center line C of the two inner gears I ₁ and I ₂ (axial axis of the rotation shaft). the center line C1 is arranged, on the straight line L passing through the rotation center line C and the first stage of the first rotational center line C1 of the outer gear O _1, and biased by a predetermined distance D on the opposite side of the first rotational centerline C1 position the second rotation axis C2 of the outer gear O ₂ of the second stage is arranged to be extended and an intermediate discharge port of the first stage pump unit and the intermediate intake port of the second stage pump unit in the axial line direction of the rotation axis Communication path (combined Is formed so as to communicate via the road).
However, in such an arrangement, the width W for arranging the first-stage pump unit and the second-stage pump unit is increased, leading to an increase in the size of the housing that accommodates the two pump units, and a reduction in size is required. Therefore, there is a need for an oil pump that can be easily applied to a small installation space while satisfying the required performance.

JP 58-93977 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the width and size of the two-stage oil pump while ensuring a desired discharge performance. It is to provide an oil pump that is easy to wear.

An oil pump according to the present invention includes a housing, a rotary shaft that is rotatably supported with respect to the housing, a first inner rotor that is housed in the housing and rotates about the axis of the rotary shaft, and a first inner A first pump unit comprising a first outer rotor that rotates about a first rotation center line that is offset from the axis along with the rotor, and a second pump that is housed in the housing and rotates about the axis of the rotation axis A second pump unit comprising an inner rotor and a second outer rotor that rotates about a second rotation center line that is offset from the axial center line in conjunction with the second inner rotor, an intake port for sucking oil from the outside, and oil An oil pump comprising: a discharge port for discharging oil to the outside; and a communication path for guiding oil from one to the other between the first pump unit and the second pump unit, The second rotation center line of the outer rotor is provided at a position deviated by a predetermined angle around the axis line from a straight line orthogonal to the axis of rotation axis and the first rotation center line of the first outer rotor. It has become.
According to this configuration, when the oil pump is applied to, for example, an engine (a state in which the oil in the oil pan is sucked and pressurized and supplied), the oil (lubricating oil) is sucked from the suction port and The pump unit (the first pump unit and the second pump unit) is discharged to the outside from the discharge port through a two-stage pressurization process, and is pumped toward various lubrication regions.
Here, the first rotation center line of the first outer rotor and the second rotation center line of the second outer rotor are not on a common straight line passing through the axis line of the rotation shaft (the second rotation center line is the axis center). Two pump units (first pump unit) with respect to the rotation axis (axial center line) because it is provided at a position deviated by a predetermined angle around the axial center line from a straight line orthogonal to the first rotation center line and the first rotation center line. And the second pump unit) can be arranged close to each other, and while ensuring the desired discharge performance, it is possible to achieve downsizing and narrowing by consolidating parts, and therefore, the wearability An oil pump with excellent performance can be obtained.

In the above configuration, the housing includes a partition wall interposed between the first pump unit and the second pump unit, the suction port is formed to face the first pump unit, and the discharge port faces the second pump unit. The partition wall is formed to be offset by a predetermined angle so as to partially overlap the intermediate discharge port in the rotational direction with respect to the intermediate discharge port for discharging oil from the first pump unit. A configuration including an intermediate suction port for sucking oil and the communication path that connects the intermediate discharge port and the intermediate suction port can be employed.
According to this configuration, the oil is sucked into the pump chamber and pressurized by the pump action of the first pump unit, and the pressurized oil passes through the communication path from the intermediate discharge port provided in the partition wall. After that, it is pumped to the intermediate suction port, and then, by the pumping action of the second pump unit, the pump chamber is sucked from the intermediate suction port and pressurized, and the pressurized oil is discharged from the discharge port to the outside. It is pumped toward the lubrication area.
Here, since the intermediate discharge port and the intermediate suction port are arranged at positions deviated by a predetermined angle so as to partially overlap each other in the rotation direction, the shaft center line of the rotation shaft and the first rotation center of the first pump unit are arranged. A smooth oil flow can be obtained while arranging the second rotation center line of the second pump unit at a position deviated by a predetermined angle from a straight line orthogonal to the line.

In the above configuration, the intermediate discharge port is continuously formed with a concave intermediate discharge chamber for guiding oil toward the downstream side, and the intermediate suction port is formed with a concave shape for guiding the oil from the upstream side. The intermediate suction chamber is formed continuously, and the intermediate discharge chamber and the intermediate suction chamber are formed to a depth that bisects the thickness of the partition wall in the direction of the rotation axis. A configuration in which the communication path is formed in an overlapping region in the rotation direction can be employed.
According to this configuration, the oil pressurized by the first pump unit is sucked into the second pump unit and pressurized through the intermediate discharge port → the intermediate discharge chamber → the communication path → the intermediate suction chamber → the intermediate suction port. Here, the communication passage is formed as an opening having substantially no thickness (passage length) formed in a region where the intermediate discharge chamber and the intermediate suction chamber overlap with each other. It can be reduced, and desired pressure characteristics and discharge performance can be obtained.

In the above configuration, the housing includes a rotor case that houses the first pump unit and the second pump unit, a housing main body that has a recess for fitting the rotor case, and a housing cover that is connected to close the opening of the housing main body. It is possible to adopt a configuration including:
According to this configuration, the first pump unit and the second pump unit (and the rotation shaft) are incorporated into the rotor case, the rotor case incorporating the two pump units is incorporated into the housing body, and the housing cover is attached. The whole assembly work can be easily performed.

In the above configuration, the housing may have a discharge port formed so as to face the first pump unit so as to discharge the aerated oil mixed with air.
According to this configuration, when the oil pump is applied to, for example, an engine (a state in which the oil in the oil pan is sucked and pressurized and supplied), the aerated oil (lubricating oil) sucked from the suction port is While being pressurized by the first pump unit, it is discharged from the discharge port to the outside and returned to the oil pan, so that the oil from which the mixed air is eliminated can be pumped to the second pump unit, and the pump performance as a whole can be improved. Can be improved.

In the above configuration, the discharge port is provided in the housing cover, and the intermediate discharge port, the intermediate discharge chamber, the intermediate suction port, the intermediate suction chamber, and the communication path are provided in the rotor case. .
According to this configuration, since all of the intermediate discharge port, the intermediate discharge chamber, the intermediate suction port, the intermediate suction chamber, and the communication path are formed in the rotor case, only the rotor case is changed as necessary. It is possible to cope with various required specifications.

The said structure WHEREIN: The 1st pump unit and the 2nd pump unit can each employ | adopt the structure which consists of 4 leaves 5 nodes containing a trochoid type inner rotor and an outer rotor.
According to this configuration, the mixed air can be efficiently discharged, a desired high discharge amount can be secured, and the pump performance and durability can be improved.

  According to the oil pump having the above configuration, in the two-stage oil pump, it is possible to achieve narrowing, downsizing, etc. while ensuring desired discharge performance, and to obtain an oil pump that can be easily equipped. Can do.

It is a schematic diagram of the oil pump which concerns on this invention. It is a front view showing one embodiment of an oil pump concerning the present invention. It is sectional drawing which shows the inside of the oil pump shown in FIG. It is a front view which shows the housing main body which makes a part of oil pump shown in FIG. FIG. 3 shows a housing cover that forms part of the oil pump shown in FIG. 2, (a) is a plan view seen from the rear R side (inner surface side), and (b) is a cross-section at E1-E1 in (a). FIG. It is sectional drawing which shows the rotor case which makes a part of oil pump shown in FIG. FIG. 7 is an end view of the rotor case shown in FIG. 6, (a) is an end view seen from the front F side, and (b) is an end view seen from the rear R side. FIG. 3 shows a side plate that forms part of the oil pump shown in FIG. 2, (a) is a plan view seen from the front F side, and (b) is a cross-sectional view taken along E2-E2 in (a). It is sectional drawing which shows a part of oil pump shown in FIG. 2, (a) is the top view which looked at the 1st pump unit (a 1st inner rotor and a 1st outer rotor) from the front F side, (b) is the 1st. It is the top view which looked at 2 pump units (the 2nd inner rotor and the 2nd outer rotor) from the front F side. It is a schematic diagram explaining size reduction of the oil pump which concerns on this invention, (a) is a schematic diagram at the time of comprising by the conventional method, (b) is a schematic diagram at the time of applying this invention. It is a schematic diagram for demonstrating the conventional oil pump.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1 to 3, the oil pump according to this embodiment includes a housing body 10 and a housing cover 20 that form a housing H, and a rotary shaft 30 that is supported by the housing H so as to be rotatable around an axis line S, The rotor case 40 incorporated in the housing H, the side plate 50 that contacts the end surface of the rotor case 40, the O-ring 60 that urges the side plate 50 toward the rotor case 40 in the direction of the axis S, and the rotor case 40 The first pump unit 70 (first inner rotor 71 and first outer rotor 72) housed in the second pump housed in the rotor case 40 adjacent to the first pump unit 70 in the direction of the axis S A unit 80 (second inner rotor 81 and second outer rotor 82) and the like are provided.
The rotor case 40 and the side plate 50 are formed separately from the housing H. However, the rotor case 40 and the side plate 50 constitute a part of the housing as accommodating the first pump unit 70 and the second pump unit 80. is there.

  The housing body 10 is formed so as to form a recess that can accommodate the first pump unit 70 and the second pump unit 80 together with the rotor case 40 by using an aluminum material for weight reduction or the like. As shown in FIG. 4, a bearing hole 11 that rotatably supports one end 31 of the rotary shaft 30 via a bearing G, a cylindrical inner peripheral surface 12 into which the rotor case 40 is fitted, and the inner peripheral surface 12 The two annular end surfaces 13 formed around the bearing hole 11 and a part of the inner peripheral surface 12 are formed by hollowing out and drilling radially outward. A suction passage 14 for sucking oil, a discharge passage 15 for discharging pressurized oil formed on the bottom side, a positioning hole 16 for positioning the side plate 50, a joint surface 17 for joining the housing cover 20, and a housing. Screw holes 18 for screwing the bolts B to fasten the Gukaba 20, and a positioning hole 19 and the like for positioning the housing cover 20.

  The housing cover 20 is made of the same aluminum material as that of the housing body 10 for weight reduction and the like, and the other end portion 32 of the rotary shaft 30 is interposed via a bearing G as shown in FIGS. The bearing hole 21 is supported rotatably, the recess 22 communicates with the suction passage 14, the suction port 23 defined by the recess 22 and the front end surface of the rotor case 40, and air mixed in the sucked oil (aeration oil) ), A circular hole 25 through which the bolt B passes, a positioning hole 26 for positioning with the housing body 10, a positioning hole 27 for positioning the rotor case 40, and the like.

The housing cover 20 is positioned so that the positioning pin fitted in the positioning hole 19 is fitted in the positioning hole 26 and the positioning hole 45a of the rotor case 40 so as to close the opening of the housing body 10. The pins are joined to the joining surface 17 so as to be fitted into the positioning holes 27, and the bolts B are passed from the outside through the circular holes 25 and screwed into the screw holes 18 so as to be connected to the housing body 10.
Here, the discharge port 24 is formed to face the first pump unit 70 as shown in FIGS. 1, 2, 5 (a) and 9 (a).
Here, since the discharge port 24 for discharging the air-mixed oil is formed so as to face the first pump unit 70, the density (mass) of the air (bubbles) mixed in the oil is small, that is, Air can be easily collected inside the pump chamber by the action of centrifugal separation, and the mixed air can be efficiently discharged.

  As shown in FIG. 3, the rotary shaft 30 is formed to extend in the direction of the axis S, and is supported by the bearing hole 11 of the housing body 10 via the bearing G. Portion 31, the other end portion 32 supported by the bearing hole 21 of the housing cover 20 via the bearing G, the shaft portion 33 for integrally rotating the first inner rotor 71 of the first pump unit 70, and the second pump unit 80. A shaft portion 34 that integrally rotates the second inner rotor 81, a shaft portion 35 that is supported by the bearing G, and the like are provided. The rotating shaft 30 is connected to a rotating member or the like that forms part of the engine and is driven to rotate.

  The rotor case 40 is formed using steel, cast iron, sintered steel, or the like. As shown in FIGS. 3, 6, and 7, the rotor case 40 has a cylindrical portion 41 centered on the axis S and a cylindrical portion 41. The inner circumferential surface 42 centering on the first rotation center line S1 (of the first outer rotor 72) and the inner side of the cylindrical portion 41 are deviated from the axial center line S by a predetermined amount. An inner peripheral surface 43 centering on the second rotation center line S2 (of the second outer rotor 82), a partition wall 44 formed between the inner peripheral surface 42 and the inner peripheral surface 43 in the axial center line S direction, Bearing holes 44a provided in the partition wall 44, intermediate discharge ports 44b and intermediate discharge chambers 44c (in the first pump unit 70) provided in the partition wall 44, and provided in the partition wall 44 (in the second pump unit 80). ) Intermediate suction chamber 44d and intermediate suction port 44e, inside The communication passage 44f that connects the discharge chamber 44c and the intermediate suction chamber 44d, the end surface 45 that the housing cover 20 contacts, the positioning hole 45a formed in the end surface 45, the end surface 46 that contacts the side plate 50, and the end surface 46 are formed. A positioning hole 46a and the like are provided.

The cylindrical portion 41 can move relatively in the direction of the axis S according to the difference in thermal deformation (expansion and contraction) between the housing body 10 and the rotor case 40 while being in close contact with the inner peripheral surface 12 of the housing body 10. It is formed to have an outer diameter dimension that fits into the housing.
The inner peripheral surface 42 is formed to have a size that allows the first outer rotor 72 of the first pump unit 70 to be inscribed so as to be rotatable (slidable) about the first rotation center line S1.
The inner peripheral surface 43 is formed to have a dimension that allows the second outer rotor 82 of the second pump unit 80 to be inscribed so as to be rotatable (slidable) about the second rotation center line S2.

As shown in FIG. 6, the partition wall 44 is for separating the first pump unit 70 and the second pump uni 80 from each other, and is formed in a flat plate shape having a predetermined thickness Wh in the direction of the axial center line S. One end face is in sliding contact with the first pump unit, and the other end face is in sliding contact with the second pump unit 80.
The intermediate discharge port 44 b discharges the oil pressurized by the first pump unit 70 and opens at one end surface of the partition wall 44.
Intermediate discharge chamber 44c is continuous with the downstream side of the intermediate discharge port 44b, it is formed a partition wall 44 into a concave shape that is hollowed by the depth W ₁ to the rear side from the front side.
The intermediate suction port 44 e is for the second pump unit 80 to suck in the oil pressurized by the first pump unit 70, and is open on the other end surface of the partition wall 44.
Intermediate suction chamber 44d is continuous with the upstream side of the intermediate suction port 44e, and is formed a partition wall 44 into a concave shape that is hollowed by the depth W ₂ to the front side from the rear side.

Here, the intermediate suction port 44e partially overlaps the intermediate discharge port 44b in the rotation direction according to the amount of deviation (from the straight line L1) of the second rotation center line S2 with respect to the first rotation center line S1. It is formed by a predetermined angle biased.
Further, the intermediate discharge chamber 44c and the intermediate suction chamber 44d have depths W ₁ and W ₂ that bisect the thickness of the partition wall 44 in the axis S direction of the rotation shaft 30 (that is, Wh = W ₁ + W ₂ ). Is formed.
The communication passage 44f is formed as an opening having substantially no thickness (passage length) while ensuring a required passage area in a region where the intermediate discharge chamber 44c and the intermediate suction chamber 44d overlap in the rotation direction. ing.

According to this, the oil is sucked into the pump chamber 23 by the pump action of the first pump unit 70 and pressurized, and the pressurized oil is fed from the intermediate discharge port 44 b provided in the partition wall 44. The oil is pumped to the intermediate suction port 44e through the communication path 44f, and subsequently sucked from the intermediate suction port 44e and pressurized by the pump action of the second pump unit 80, and the pressurized oil is discharged to the discharge port 52. It is designed to be discharged from the outside.
Here, since the intermediate discharge port 44b and the intermediate suction port 44e are disposed at positions that are deviated from each other by a predetermined angle in the rotation direction, the axis S of the rotation shaft 30 and the first rotation center line of the first pump unit 70 are disposed. A smooth oil flow can be obtained while arranging the second rotation center line S2 of the second pump unit 80 at a position deviated by a predetermined angle from the straight line L1 orthogonal to S1.
In particular, when the pressurized oil is sucked into the second pump unit 80 via the intermediate discharge port 44b → the intermediate discharge chamber 44c → the communication passage 44f → the intermediate suction chamber 44d → the intermediate suction port 44e, the intermediate discharge chamber 44c And the intermediate suction chamber 44d are formed, and the communication passage 44f is formed as an opening having substantially no thickness (passage length), so that passage resistance and pressure loss can be reduced, and desired pressurization characteristics can be obtained. And discharge performance can be obtained.

  The rotor case 40 cooperates with the end surface 13 in a state where the first pump unit 70 is accommodated on the inner peripheral surface 42 and the second pump unit 80 is accommodated on the inner peripheral surface 43 together with the rotary shaft 30. A positioning pin fitted in the positioning hole 16 is fitted into the positioning hole 46a while sandwiching the side plate 50, and is assembled (fitted) to the inner peripheral surface 12 of the housing body 10.

The side plate 50 is formed in a disc shape using steel, cast iron, sintered steel, aluminum alloy or the like, and as shown in FIGS. 3 and 8, a circular hole 51 through which the rotary shaft 30 passes, a downstream pump A discharge port 52 for discharging the oil pressurized by the unit 80, a positioning hole 53, a recess 54 for receiving one end side of the bearing G, and the like are provided.
Then, the side plate 50 is assembled to the housing body 10 such that the positioning pin fitted in the positioning hole 16 of the housing body 10 passes through the positioning hole 53 and the O-ring 60 is sandwiched between the side plate 50 and the end surface 13. It has become.

  The O-ring 60 is formed in an annular shape by an elastically deformable rubber material or the like, and is disposed between the end surface 13 of the housing body 10 and the side plate 50 so that the side plate 50 faces the end surface 46 of the rotor case 40. In order to energize, it is compressed and assembled by a predetermined compression amount in the direction of the axis S.

The first pump unit 70 is formed using steel, sintered steel, or the like, and as illustrated in FIG. 9A, the first inner rotor 71 that rotates around the axis line S together with the rotating shaft 30. And a four-leaf five-section trochoid pump composed of a first outer rotor 72 that rotates about a first rotation center line S1 provided at a position deviated from the axis S by a predetermined distance. is there.
The first inner rotor 71 is formed as an external gear having a fitting hole 71a for fitting the shaft portion 33 of the rotating shaft 30 and having four peaks and valleys (dents) on the outer periphery thereof.
The first outer rotor 72 has an outer peripheral surface 72 a that is slidably fitted to the inner peripheral surface 42 of the rotor case 40, and four crests (external teeth) and troughs of the first inner rotor 71 on the inner periphery thereof ( It is formed as an internal gear having five ridges (inner teeth) and valleys (dents) that mesh with the dents.

  When the first inner rotor 71 rotates together with the rotary shaft 30 in the direction of the arrow (clockwise in FIG. 9A) about the axis S, the first outer rotor 72 is interlocked to the first By rotating around the rotation center line S1 in the direction of the arrow (clockwise in FIG. 9A), the volume of the pump chamber P defined by both changes, and the oil is sucked from the suction port 23, followed by In the pressurizing process, the aerated oil is discharged from the discharge port 24, and then the remaining oil is discharged from the intermediate discharge port 44b toward the second pump unit 80, and this process is repeated continuously. It is like that.

The second pump unit 80 is formed using steel, sintered steel, or the like, and as shown in FIG. 9B, the second inner rotor 81 that rotates around the axis line S together with the rotating shaft 30. And a second outer rotor that rotates about a second rotation center line S2 provided at a position deviated by a predetermined angle θ around the axis line S from the straight line L1 perpendicular to the axis line S and the first rotation center line S1. 82, and a four-leaf, five-section trochoid pump.
The second inner rotor 81 is formed as an external gear having a fitting hole 81a for fitting the shaft portion 34 of the rotating shaft 30 and having four peaks and valleys (dents) on the outer periphery.
The second outer rotor 82 has an outer peripheral surface 82a that is slidably fitted to the inner peripheral surface 43 of the rotor case 40, and has four crests (external teeth) and troughs (dents) of the second inner rotor 81 on the inner periphery. ) Is formed as an internal gear having five peaks (inner teeth) and valleys (dents).

  When the second inner rotor 81 rotates together with the rotary shaft 30 in the direction of the arrow (clockwise in FIG. 9B) about the axis S, the second outer rotor 82 is interlocked with the second outer rotor 82. By rotating in the direction of the arrow (clockwise in FIG. 9B) around the rotation center line S2, the volume of the pump chamber P defined by both changes, and oil is sucked from the intermediate suction port 44e. The pressure is applied and subsequently discharged from the discharge port 52 toward the external lubricating region, and this process is continuously repeated.

Here, the second rotation center line S2 of the second outer rotor 82 is about the axis S from the straight line L1 orthogonal to the axis S of the rotation shaft 30 and the first rotation center line S1 of the first outer rotor 72. A position deviated by a predetermined angle θ (the straight line L2 orthogonal to the second rotation center line S2 and the axial center line S forms an angle θ with the straight line L1), that is, the first outer rotor 72 of the first outer rotor 72 Since the one rotation center line S1 and the second rotation center line S2 of the second outer rotor 82 are not on a common straight line passing through the axis line S of the rotation shaft 30, the rotation axis 30 (axis line S) is The two pump units (the first pump unit 70 and the second pump unit 80) can be arranged close to each other, and while ensuring the desired discharge performance, it is possible to reduce the size and width by consolidating parts. Can be achieved and hence Thus, an oil pump excellent in outfitting can be obtained.
Specifically, as shown in FIG. 10, when the conventional method is applied, the width dimension _OLD becomes as shown in FIG. 10 (a), whereas when the present invention is applied, FIG. As shown in b), the width dimension can be set to W _NEW (<W _OLD ), and downsizing and narrowing can be achieved by consolidating parts.

When the oil pump having the above configuration is assembled, the housing H is configured by the housing body 10 and the housing cover 20, and the first pump unit 70 and the second pump unit 80 are separated in advance into the rotor case 40 that defines the partition wall 44. Therefore, the first pump unit 70 and the second pump unit 80 are arranged in the rotor case 40 together with the rotary shaft 30, and the O-ring 60, the side plate 50, and the rotor case 40 are arranged. The assembly work can be performed simply by sequentially accommodating the housing body 10 and then attaching the housing cover 20 thereon.
Further, the rotor case 40 is adopted, and in the rotor case 40, all of the intermediate discharge port 44b, the intermediate discharge chamber 44c, the intermediate suction port 44e, the intermediate suction chamber 44d, and the communication passage 44f are formed. By changing only the rotor case as appropriate, various required specifications can be met.

Next, the operation of the oil pump will be described with reference to FIGS. 9 (a) and 9 (b).
First, when the rotating shaft 30 is rotationally driven by the engine, the first pump unit 70 (the first inner rotor 71 and the first outer rotor 72) rotates clockwise in FIG. Then, the air is sucked into the pump chamber P of the first pump unit 70 through the suction passage 14 → the suction port 23.
Then, the oil sucked into the pump chamber P is pressurized by the continuous rotation of the first pump unit 70, and in this pressurizing process, the aerated oil is positively discharged from the discharge port 24 as a predetermined discharge amount. Furthermore, the remaining oil passes through the intermediate discharge port 44b → the intermediate discharge chamber 44c → the communication passage 44f → the intermediate suction chamber 44d → the intermediate suction port 44e toward the second pump unit 80 with a predetermined discharge pressure. The pressure is increased and discharged (supplied).

Subsequently, when the second pump unit 80 (the second inner rotor 81 and the second outer rotor 82) rotates clockwise in FIG. 9B, the oil passes through the intermediate suction chamber 44d → the intermediate suction port 44e. Then, it is sucked into the pump chamber P of the second pump unit 80.
The oil sucked into the pump chamber P is pressurized by the continuous rotation of the second pump unit 80, passes through the discharge port 52 → the discharge passage 15, and moves toward the external lubrication region with a predetermined discharge pressure and The ink is discharged (supplied) at a predetermined discharge amount.

  In practice, the first pump unit 70 (the first inner rotor 71 and the first outer rotor 72) and the second pump unit 80 (the second inner rotor 81 and the second outer rotor 82) cooperate with each other in the first stage. Intake of oil from the oil pan OP in the first stage → Pressurization of oil in the first stage → Discharge of mixed air and oil in the first stage → Discharge of the remaining oil downstream in the first stage (second stage) Oil suction in the second stage) → pressurization of oil in the second stage → discharge of oil in the second stage is continuously performed.

In the above embodiment, the case where the present invention is adopted in the configuration including the rotor case 40 and the side plate 50 as the second housing inside the housing (the housing main body 10 and the housing cover 20) is shown. The present invention may be applied to a configuration in which the rotor case 40, the side plate 50, and the like are eliminated.
In the above embodiment, a two-stage trochoid including the first pump unit 70 (the first inner rotor 71 and the first outer rotor 72) and the second pump unit 80 (the second inner rotor 81 and the second outer rotor 82). However, the present invention is not limited to this, and the present invention is applied to a configuration including an inner gear (involute) type inner rotor and outer rotor. May be.

In the above-described embodiment, the case where the present invention is adopted in the configuration in which the housing is separated into the housing main body and the housing cover is shown. However, the present invention is not limited to this. You may apply this invention in the structure provided with the housing which consists of a housing half body and a 2nd housing half body.
In the above-described embodiment, the case where the oil pump according to the present invention is applied to an engine mounted on an automobile or the like has been described. However, the present invention is not limited to this, for example, a continuously variable transmission (CVT) other than the engine. It can also be applied to.

  As described above, according to the oil pump of the present invention, in the two-stage oil pump, it is possible to achieve narrowing, downsizing, etc. while ensuring desired discharge performance, and also improve the wearability. Therefore, it can be applied to an engine mounted on an automobile or the like, a two-wheeled vehicle, a vehicle mounted with another engine, a continuously variable transmission (CVT) or other mechanism that requires pumping of lubricating oil Etc. are also useful.

H Housing 10 Housing body (housing)
11 Bearing hole 12 Inner peripheral surface 13 End surface 14 Suction passage 15 Discharge passage 16 Positioning hole 17 Joint surface 18 Screw hole 19 Positioning hole 20 Housing cover (housing)
21 bearing hole 22 recess 23 suction port 24 discharge port 25 circular hole 26, 27 positioning hole 30 rotation axis S shaft center line 31 one end 32 other end 33, 34, 35 shaft 40 rotor case 41 cylindrical part 42 inner peripheral surface 43 inner peripheral surface 44 partition wall 44a bearing hole 44b intermediate discharge port 44c intermediate discharge chamber 44d intermediate suction chamber 44e intermediate suction port 44f communication path 45, 46 end face 45a, 45a positioning hole 50 side plate 51 circular hole 52 discharge port 53 positioning hole 54 recessed portion 60 O-ring 70 first pump unit P pump chamber 71 first inner rotor 71a fitting hole 72 first outer rotor S1 first rotation center line 72a outer peripheral surface 80 second pump unit 81 second inner rotor 81a fitting hole 82 2nd outer rotor S2 2nd rotation center line 82a Outer peripheral surface

Claims (7)

A housing, a rotating shaft supported rotatably with respect to the housing, a first inner rotor housed in the housing and rotating about an axis of the rotating shaft, and interlocked with the first inner rotor A first pump unit comprising a first outer rotor rotating about a first rotation center line deviated from the axis, and a second pump housed in the housing and rotated about the axis of the rotation axis A second pump unit comprising an inner rotor, a second outer rotor that rotates about a second rotation center line that is offset from the axial center line in conjunction with the second inner rotor, and a suction port that sucks oil from outside An oil port comprising: a discharge port for discharging oil to the outside; and a communication path for guiding oil from one to the other between the first pump unit and the second pump unit. A-flops,
The second rotation center line of the second outer rotor is provided at a position deviated by a predetermined angle around the axis line from a straight line orthogonal to the axis line and the first rotation center line of the first outer rotor. ,
An oil pump characterized by that. The housing includes a partition wall interposed between the first pump unit and the second pump unit,
The suction port is formed to face the first pump unit,
The discharge port is formed to face the second pump unit,
The partition wall is formed with an intermediate discharge port for discharging oil from the first pump unit and a predetermined angle biased so as to partially overlap the intermediate discharge port in the rotation direction. An intermediate suction port for inhaling air, and the communication passage for communicating the intermediate discharge port and the intermediate suction port.
The oil pump according to claim 1. The intermediate discharge port is continuously formed with an intermediate discharge chamber formed in a concave shape to guide oil toward the downstream side,
The intermediate suction port is continuously formed with an intermediate suction chamber formed in a concave shape to guide oil from the upstream side,
The intermediate discharge chamber and the intermediate suction chamber are formed to a depth that bisects the thickness of the partition wall in the direction of the rotation axis,
The communication path is formed in a region where the intermediate discharge chamber and the intermediate suction chamber overlap in the rotation direction.
The oil pump according to claim 2. The housing includes a rotor case that houses the first pump unit and the second pump unit, a housing body that has a recess for fitting the rotor case, and a housing cover that is coupled to close an opening of the housing body. including,
The oil pump according to claim 3. The housing has a discharge port formed so as to face the first pump unit so as to discharge air-containing oil mixed with air.
The oil pump according to claim 4. The outlet is provided in the housing cover;
The intermediate discharge port, the intermediate discharge chamber, the intermediate suction port, the intermediate suction chamber, and the communication path are provided in the rotor case.
The oil pump according to claim 5. Each of the first pump unit and the second pump unit is composed of four lobes and five nodes including a trochoid inner rotor and an outer rotor, respectively.
The oil pump according to any one of claims 1 to 6, wherein the oil pump is provided.

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