JPWO2013115292A1 - Oil pump - Google Patents

Abstract

The oil pump of the present invention includes a housing (10, 20) having a suction port (44b) for sucking oil, a discharge port (52) for discharging oil, and a purge port (24) for discharging air-containing oil. An inner rotor (71, 81) disposed rotatably around a predetermined axis (S) and an outer rotor (72, 82) disposed to rotate in conjunction with the inner rotor in the housing. A filter member (90) is provided for preventing foreign matter from entering from the outside through the purge port. Thereby, even if the oil is sucked from the purge port, it is possible to prevent foreign matters from entering.

Description

  The present invention relates to an oil pump that sucks and discharges oil (lubricating oil) such as an internal combustion engine (engine), and more particularly to a trochoid oil pump including an inner rotor and an outer rotor.

  The trochoidal oil pump has a housing, an outer rotor having inner teeth rotatably arranged in the housing, an outer tooth that engages with the inner teeth of the outer rotor, and a volume change in cooperation with the outer rotor. In a configuration provided with an inner rotor that defines a pump chamber with a rotating shaft, a rotary shaft that is rotatably supported by the housing to rotate the inner rotor, a suction port that sucks oil into the housing, and a discharge port that discharges oil A purge port (air vent hole, bubble exhaust port, deaeration port) etc. for discharging air mixed in oil is provided, the inner rotor is rotated via the rotating shaft, and the outer rotor is rotated in conjunction with the rotation of the inner rotor. To obtain pumping action, inhale and pressurize oil from the inlet, and discharge pressurized oil from the outlet Those to discharge the air mixed into the oil (gas bubbles) or the like from the purge port is known (for example, see Patent Document 1, Patent Document 2, Patent Document 3, etc.).

  By the way, in the oil pump, the purge port (air vent hole, bubble discharge port, deaeration port) is a part corresponding to the pressurizing chamber (compression stroke) and provided on the side close to the discharge port. In the normal rotation range, although the oil mixed with air was discharged from the purge port, there was no situation where the oil was sucked.

  On the other hand, the inventor has developed an oil pump having characteristics corresponding to a wide range of engine rotation, and the ratio between the oil discharge amount and the purge discharge amount (amount of discharged air-containing oil from the purge port) Depending on the setting due to the difference in rotor size, the pump chamber may communicate with the purge port at the same time as the purge port, and oil is sucked from the purge port when the engine is started. It has been found that oil is sucked from the purge port due to the delay in following the stroke.

JP-A-9-203308 JP-A-6-167278 Microfilm of Japanese Utility Model Application No. 2-1077738 (Japanese Utility Model Application Publication No. 4-65974)

  The present invention has been made in view of the above circumstances, and the object of the present invention is to prevent sticks and the like due to contamination by foreign matters even when oil is sucked from the purge port. Improve pump performance and durability in a wide range of engine speeds from low to high speeds, including rotation areas where there is little air mixing and rotation areas where air mixing is not important. An object of the present invention is to provide an oil pump capable of improving the performance of the engine.

An oil pump according to the present invention includes a housing having a suction port for sucking oil, a discharge port for discharging oil, and a purge port for discharging air-containing oil mixed with air, and is rotatable around a predetermined axis in the housing. An oil pump comprising an inner rotor arranged and an outer rotor arranged to rotate in conjunction with the inner rotor in the housing, and foreign matter enters the housing from the outside through a purge port. The filter member which prevents this is provided.
According to this configuration, when this oil pump is applied to, for example, an engine (in a state where the oil pump is disposed in the oil pan), the oil (lubricating oil) is supplied to the inner rotor and the outer rotor under normal operating conditions. As a result of the pumping action, the aspirated oil is sucked into the pump chamber, and then the aerated oil is pressurized, and then a part of the aerated oil passes from the purge port to the outside of the housing (in the oil pan). Then, the remaining oil is discharged from the discharge port and is pumped toward various lubrication regions.
On the other hand, when the engine is started, the oil level in the oil pan is high, and during high-speed rotation, oil may be sucked from the purge port due to a delay in following the intake stroke. In this case, the oil passes through the filter member and passes through the pump chamber. Therefore, it is possible to prevent sticks and the like due to contamination of foreign matters and the like, thus ensuring the expected pump performance and improving pump performance and durability in a wide range of engine rotation.

In the above-described configuration, a configuration may be employed in which the purge port is disposed in a region that can communicate with the pump chamber defined by the inner rotor and the outer rotor simultaneously with the suction port.
According to this configuration, depending on the rotational speed, when oil is sucked into the pump chamber through the suction port, the oil is also sucked from the purge port. Can be used as a pump for sucking and discharging oil.

In the above configuration, the housing includes a housing main body having a recess for accommodating the inner rotor and the outer rotor, and a housing cover connected to close the opening of the housing main body, the housing cover being formed with a purge port, The filter member can employ a configuration that is attached to the housing cover from the outside.
According to this configuration, the filter member can be easily attached or detached from the outside of the housing, and therefore, the filter member can be easily replaced without disassembling the housing.

In the above configuration, the inner rotor and the outer rotor are arranged adjacent to each other in the direction of the axis, and are an upstream rotor composed of the first inner rotor and the first outer rotor, and a downstream composed of the second inner rotor and the second outer rotor. The housing includes a spacer member interposed between the upstream rotor and the downstream rotor, the suction port is provided so as to face the upstream rotor, and the discharge port faces the downstream rotor The purge port is provided so as to face the upstream rotor, and the spacer member is provided with a communication port that guides the oil discharged from the upstream rotor to the downstream rotor. Can do.
According to this configuration, since the two-stage trochoidal pump of the upstream rotor and the downstream rotor is adopted, desired pump characteristics can be ensured while achieving a reduction in the outer diameter of the apparatus. Since the suction port, the purge port, and the discharge port are arranged as described above, the pump efficiency can be increased.

The said structure WHEREIN: The structure provided in the spacer member so that an inlet may face an upstream rotor between an upstream rotor and a downstream rotor can be employ | adopted.
According to this configuration, the oil sucked from the suction port can be reliably pressurized in the upstream rotor and sent out to the downstream rotor through the communication port, and the pump performance as a whole can be improved.

In the above configuration, the inner rotor and the outer rotor may adopt a configuration including four leaves and five nodes.
According to this configuration, it is possible to improve pump performance and durability while ensuring a desired discharge amount in a configuration in which an arrangement in which the suction port and the purge port communicate with the pump chamber at the same time is easily established.

In the above configuration, the purge port is formed so as to open in a substantially L shape extending in the rotational direction of the inner rotor and the outer rotor at the radially outer end thereof while extending in the radial direction passing through the axis. Can be adopted.
According to this configuration, air can be efficiently discharged from the purge port.

  According to the oil pump configured as described above, even if oil is sucked in from the purge port, it is possible to prevent sticks and the like due to contamination of foreign matters, etc., and to guarantee the expected pump performance, and also in a rotation region with less air contamination In a wide engine rotation range from a low rotation range to a high rotation range including a rotation range where importance is not placed on air and air mixing, improvement of pump characteristics, improvement of durability, etc. can be achieved.

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. 2 is a plan view showing a housing cover forming a part of the oil pump shown in FIG. 1 and viewed from the rear R side (inner surface side). FIG. 4 is a cross-sectional view taken along line E1-E1 in FIG. 4A, showing a housing cover that forms part of the oil pump shown in FIG. 1. It is sectional drawing which decomposed | disassembled and showed the housing cover, filter member, and fixing ring which comprise a part of oil pump shown in 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 and is an end view as seen from the front F side. FIG. 7 is an end view of the rotor case shown in FIG. 6 and is an end view as seen from the rear R side. FIG. 2 is a plan view showing a side plate forming a part of the oil pump shown in FIG. 1 and viewed from the front F side. FIG. 8 is a cross-sectional view taken along line E2-E2 in FIG. 8A, showing a side plate that forms part of the oil pump shown in FIG. 1. FIG. 2 is a plan view showing an inner rotor and an outer rotor that constitute a part of the oil pump shown in FIG. 1, and an upstream rotor composed of a first inner rotor and a first outer rotor as viewed from the rear R side. FIG. 2 is a plan view showing an inner rotor and an outer rotor that constitute a part of the oil pump shown in FIG. 1, and a downstream rotor composed of a second inner rotor and a second outer rotor as viewed from the front F side. It is the top view seen from the back R side which shows the relationship between the suction port with respect to the pump chamber defined by the 1st inner rotor and 1st outer rotor which comprise an upstream rotor, and a 1st outer rotor. It is a disassembled sectional view which shows other embodiment of the attachment method of the filter member which makes a part of oil pump shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1 and 2, the oil pump according to this embodiment includes a housing main body 10 and a housing cover 20 that form a housing, a rotary shaft 30 that is rotatably supported around the axis S by the housing, and is incorporated in the housing. The rotor case 40, the side plate 50 that contacts the end face of the rotor case 40, the O-ring 60 as a biasing member that biases the side plate 50 toward the rotor case 40 in the direction of the axis S, and the rotor case 40 are accommodated. The upstream rotor 70 composed of the first inner rotor 71 and the first outer rotor 72, the second inner rotor 81 and the second outer rotor housed in the rotor case 40 adjacent to the upstream rotor 70 in the direction of the axis S A downstream rotor 80 composed of a rotor 82 and a flange attached to the housing cover 20. And a filter member 90 or the like.

  The housing body 10 is formed so as to form a recess that can accommodate the upstream rotor 70 and the downstream rotor 80 together with the rotor case 40 by using an aluminum material for weight reduction or the like. As shown in FIG. 2, the bearing hole 11 that rotatably supports the one end 31 of the rotary shaft 30 via the bearing G, the cylindrical inner peripheral surface 12 into which the rotor case 40 is fitted, and the inner peripheral surface 12 It is formed by reducing the diameter so as to form a step, and by forming a portion of two annular end faces 13 and an inner peripheral surface 12 formed around the bearing hole 11 radially outward and drilling. 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 the housing cover 2 Screw holes 18 for screwing the bolts B for fastening the, 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 as shown in FIGS. 1, 2, 4A, 4B, and 5, the other end of the rotary shaft 30 is formed. A bearing hole 21 that rotatably supports 32 via a bearing G, a recess 22 that faces a suction port 44b described later in the direction of the axis S, a recess 23 that faces a communication port 44e described later in the direction of the axis S, a suction A purge port 24 for discharging air mixed in the oil (air-mixed oil), a circular hole 25 through which the bolt B passes, a positioning hole 26 for positioning with the housing body 10, and a positioning hole 27 for positioning the rotor case 40 Further, a cylindrical counterbore portion 28 and the like into which the filter member 90 and the fixing ring 91 are fitted are provided.

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, as shown in FIGS. 4A and 9A, the purge port 24 extends in the radial direction passing through the axis S, and at the radially outer end thereof, the rotation direction of the first inner rotor 71 and the first outer rotor 72 (arrows). It is formed so as to open in a substantially L shape extending in the direction). Thereby, the air can be efficiently discharged from the purge port 24.
The purge port is not limited to the purge port 24 having the above-described form, and a desired form can be appropriately adopted according to a target purge discharge amount or the like.

As shown in FIG. 2, the rotating shaft 30 is formed to extend in the direction of the axis S using steel or the like, and is supported by the bearing hole 11 of the housing body 10 via the bearing G. , 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 upstream rotor 70, and the second inner portion of the downstream rotor 80. A shaft portion 34 that integrally rotates the 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. 2, 6, 7 </ b> A, and 7 </ b> B, the cylindrical portion 41 and the cylindrical portion 41 centering on the axis S are provided. An inner peripheral surface 42 centered on an axis L1 deviated by a predetermined amount from the axis S inside, an inner peripheral surface 43 centered on an axis L2 deviated from the axis S by a predetermined amount inside the cylindrical portion 41, and the direction of the axis S An intermediate wall portion 44 as a spacer member formed between the inner peripheral surface 42 and the inner peripheral surface 43, a bearing hole 44a provided in the intermediate wall portion 44, a suction port 44b provided in the intermediate wall portion 44, An upstream rotor discharge port 44c provided in the intermediate wall 44, a downstream rotor intake port 44d provided in the intermediate wall 44, and a communication port through which the upstream rotor discharge port 44c and the downstream rotor intake port 44d communicate with each other. 44e, housing cover 20 end surface 45 abuts includes positioning holes 45a formed in the end face 45, the end face 46 side plate 50 is in contact, the positioning hole 46a or the like formed on the end face 46.

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 upstream rotor 70 to be inscribed so as to be rotatable (slidable) about the axis L1.
The inner peripheral surface 43 is formed to have a dimension that allows the second outer rotor 82 of the downstream rotor 80 to be inscribed so as to be rotatable (slidable) about the axis L2.
The suction port 44b communicates with the suction passage 14 and is formed so as to face the upstream rotor 70 (the pump chamber P thereof).
Thus, since the suction port 44b is provided between the upstream rotor 70 and the downstream rotor 80 so as to face the upstream rotor 70, the oil sucked from the suction port 44b is supplied to the upstream rotor 70. It is possible to pressurize the inside reliably and send it to the downstream rotor 80 through the communication port 44e, thereby improving the pump performance as a whole.
The communication port 44e is formed so that the upstream rotor discharge port 44c and the downstream rotor suction port 44d communicate with each other, and the oil discharged from the upstream rotor 70 is guided to the downstream rotor 80.
The rotor case 40 cooperates with the end surface 13 in the state in which the upstream rotor 70 is accommodated on the inner peripheral surface 42 and the downstream rotor 80 is accommodated on the inner peripheral surface 43 together with the rotary shaft 30, and the O-ring 60 and the side plate. The positioning pin fitted into the positioning hole 16 while being sandwiched 50 is fitted into the inner peripheral surface 12 of the housing body 10 so as to be fitted into the positioning hole 46a.

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. 2 and 8, a circular hole 51 through which the rotary shaft 30 passes, a downstream rotor, and the like. A discharge port 52 for discharging the oil pressurized by 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 upstream rotor 70 is formed using steel, sintered steel, or the like, and includes a first inner rotor 71 and a first outer rotor 72 as shown in FIG. 9A.
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.
That is, the upstream rotor 70 (the first inner rotor 71 and the first outer rotor 72) constitutes a trochoid pump having four leaves and five nodes.

When the first inner rotor 71 rotates together with the rotary shaft 30 in the direction of the arrow (counterclockwise in FIG. 9A) about the axis S, the first outer rotor 72 is interlocked to move the arrow about the axis L1. By rotating in the direction (counterclockwise in FIG. 9A), the volume of the pump chamber P defined by both changes, and the oil is sucked from the suction port 44b and subsequently pressurized. The aerated oil is discharged from the purge port 24, and then the remaining oil is discharged from the upstream rotor discharge port 44c toward the downstream rotor 80, and this process is continuously repeated.
Further, as shown in FIG. 10, the purge port 24 is disposed in a region that can communicate with the pump chamber P defined by the first inner rotor 71 and the first outer rotor 72 simultaneously with the suction port 44 b. . Therefore, when the oil level in the oil pan at the time of starting the engine is high or when the follow-up delay of the intake stroke occurs when the engine rotates at high speed, the oil can be sucked into the pump chamber P from the purge port 24. .
That is, depending on the rotational speed, when oil is sucked into the pump chamber P through the suction port 44b, the oil is also sucked from the purge port 24. Therefore, in the rotation region where the air content is low or the exhaustion of air is not important. However, it can be used as a pump that sucks and discharges oil.

The downstream rotor 80 is formed using steel, sintered steel, or the like, and includes a second inner rotor 81 and a second outer rotor 82 as shown in FIG. 9B.
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).
That is, the downstream rotor 80 (the second inner rotor 81 and the second outer rotor 82) constitutes a four-leaf five-section trochoid pump.

  When the second inner rotor 81 rotates together with the rotary shaft 30 in the arrow direction (clockwise in FIG. 9B) around the axis S, the second outer rotor 82 is interlocked to move in the arrow direction around the axis L2. By rotating in the clockwise direction in FIG. 9B, the volume of the pump chamber P defined by both changes, and the oil is sucked from the downstream suction port 44d, then pressurized, and then the oil is discharged. It discharges toward the external lubrication area | region from the exit 52, and this process is repeated continuously.

As described above, since the two-stage trochoidal pump of the upstream rotor 70 and the downstream rotor 80 is adopted, it is possible to ensure desired pump characteristics while achieving a reduction in the outer diameter of the device, Further, since the suction port 44b, the purge port 24, and the discharge port 52 are arranged as described above, the pump efficiency can be increased.
The rotor case 40 and the side plate 50 constitute a second housing that further accommodates the upstream rotor 70 and the downstream rotor 80 inside the housing (the housing body 10 and the housing cover 20).
Since the rotor case 40 and the side plate 50 are made of the same material (steel or sintered steel) as the upstream rotor 70 and the downstream rotor 80, the housing (housing body 10) made of an aluminum material. Even if the housing cover 20) is thermally expanded and a clearance is generated in the axis S direction, the rotor case 40 and the side plate 50 are attached to one side in the axis S direction by the urging force of the O-ring 60. Therefore, a gap is not generated between both side surfaces of the upstream rotor 70 and both side surfaces of the downstream rotor 80, and desired pump performance (discharge characteristics) can be ensured.

As shown in FIGS. 1 and 5, the filter member 90 has a mesh shape with a predetermined size so as to remove foreign matters mixed in the oil, and has a semicircular sphere with an annular flange. It is formed to make.
Then, the filter member 90 is fitted into the counterbore portion 28 so as to cover the purge port 24 of the housing cover 20, and the annular fixing ring 91 is fitted from above to be attached to the housing cover 20 from the outside. It is like that.
In this way, the filter member 90 can be easily attached or removed from the outside of the housing (housing body 10 and housing cover 20), and therefore the filter member can be removed without disassembling the housing (housing body 10 and housing cover 20). 90 replacement work and the like can be easily performed.
The filter member is not limited to the mesh-like filter member 90 formed in a hemispherical shape and the fixing ring 91 for fixing the filter member as described above, and the filter member and the fixing method have other configurations and forms. Can be adopted.
For example, as shown in FIG. 11, a C-shaped snap ring 91 ′ is adopted instead of the fixing ring 91, and an annular groove 28 ′ is provided on the inner peripheral surface of the counterbore portion 28 of the housing cover 20. It may be adopted.
According to this, the filter member 90 is fitted into the counterbore part 28 so as to cover the purge port 24 of the housing cover 20, and from above, the C-shaped snap ring 91 ′ is fitted into the annular groove 28 ′. The housing cover 20 is attached from the outside.
In this case as well, the filter member 90 can be easily attached or removed from the outside of the housing (housing body 10 and housing cover 20), and therefore without disassembling the housing (housing body 10 and housing cover 20). The replacement work of the filter member 90 can be easily performed.

Next, the operation of the oil pump will be described with reference to FIGS. 9A, 9B, and 10. FIG.
First, when the engine is in the normal rotation region (when oil is not sucked from the purge port 24), the upstream rotor 70 (the first inner rotor 71 and the first outer rotor 72) is counterclockwise in FIG. 9A. By rotating around, the oil is sucked into the pump chamber P of the upstream rotor 70 via the suction passage 14 → the suction port 44 b.

  The oil sucked into the pump chamber P is pressurized by the continuous rotation of the upstream rotor 70, and the aerated oil is positively discharged from the purge port 24 to the outside during this pressurization process. This oil is guided to the downstream rotor 80 through the upstream rotor discharge port 44c → the communication port 44e → the downstream rotor suction port 44d.

Subsequently, when the downstream rotor 80 (the second inner rotor 81 and the second outer rotor 82) rotates clockwise in FIG. 9B, the oil is supplied from the downstream rotor intake port 44d to the pump chamber of the downstream rotor 80. It is sucked into P.
The oil sucked into the pump chamber P is pressurized by the continuous rotation of the downstream rotor 80 and supplied to the external lubrication region via the discharge port 52 → the discharge passage 15.

  Actually, the pump chambers of the upstream rotor 70 (the first inner rotor 71 and the first outer rotor 72) and the downstream rotor 80 (the second inner rotor 81 and the second outer rotor 82) cooperate with each other. Are continuously inhaling oil, pressurizing oil, discharging mixed air (oil mixed with air), and discharging oil.

On the other hand, when the engine is started (when the oil level in the oil pan is high) or at high speed (when the follow-up delay of the intake stroke occurs with respect to the original pump stroke), as shown in FIG. In the pump chamber P of the upstream rotor 70 (defined by the first inner rotor 71 and the first outer rotor 72), oil is sucked not only from the suction port 44b but also from the purge port 24. That is, when the oil is sucked into the pump chamber P through the suction port 44b, the oil is also sucked from the purge port 24. Therefore, the oil is sucked even in the rotation region where the air content is low or the rotation region where air discharge is not important. Then, it can be used as a pump for discharging.
In this case, since the filter member 90 is provided at the purge port 24, foreign matter or the like accumulated in the oil pan can be prevented from being sucked into the pump P. Therefore, the upstream rotor 70 and the downstream rotor 80 It is possible to prevent sticks and the like, guarantee the expected pump performance, and achieve improvement in pump performance and durability in a wide range of engine rotation.

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 trochoidal pump including the upstream rotor 70 (first inner rotor 71 and first outer rotor 72) and the downstream rotor 80 (second inner rotor 81 and second outer rotor 82). However, the present invention is not limited to this, and the present invention may be applied to a configuration including a pair of inner rotor and outer rotor.

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 embodiment, the trochoid pump is shown as the oil pump. However, the present invention is not limited to this, and the present invention may be applied to an internal gear type oil pump or an external gear type oil pump. Good.

  As described above, according to the oil pump of the present invention, even if oil is sucked from the purge port, it is possible to prevent sticking due to foreign matters and the like to guarantee the expected pump performance, Because it can achieve improved pump characteristics and improved durability in a wide range of engine speeds from low to high speeds, including rotation areas with little contamination and rotation areas that do not place importance on air, automobiles, etc. Of course, the present invention can be applied to an engine mounted on a motorcycle, and is also useful for a motorcycle, a vehicle equipped with another engine, or other mechanisms that require pumping of lubricating oil.

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 concave portion 23 concave portion 24 purge port 25 circular hole 26 positioning hole 27 positioning hole 28 counterbore portion 30 'annular groove 30 rotating shaft S axis 31 one end portion 32 other end portions 33, 34, 35 shaft portion 40 rotor case 41 Cylindrical portion 42 Inner peripheral surface 43 Inner peripheral surface 44 Intermediate wall portion (spacer member)
44a Bearing hole 44b Suction port 44c Upstream rotor discharge port 44d Downstream rotor suction port 44e Communication port 45 End surface 45a Positioning hole 46 End surface 46a Positioning hole 50 Side plate 51 Circular hole 52 Discharge port 53 Positioning hole 54 Recess 60 O-ring 70 Upstream Side rotor P Pump chamber 71 First inner rotor 71a Fitting hole 72 First outer rotor L1 Axis 72a outer peripheral surface 80 Downstream rotor P Pump chamber 81 Second inner rotor 81a Fitting hole 82 Second outer rotor L2 Axis 82a outer peripheral surface 90 Filter member 91 Fixing ring 91 'Snap ring

Claims (7)

A housing having a suction port for sucking oil, a discharge port for discharging oil, and a purge port for discharging air-containing oil mixed with air;
An inner rotor disposed so as to be rotatable around a predetermined axis in the housing;
An outer rotor arranged to rotate in conjunction with the inner rotor in the housing;
An oil pump comprising:
The housing is provided with a filter member for preventing foreign matter from entering from the outside through the purge port.
An oil pump characterized by that. The purge port is disposed in a region where the purge port can communicate with the suction port simultaneously with the pump chamber defined by the inner rotor and the outer rotor.
The oil pump according to claim 1. The housing includes a housing main body having a recess for accommodating the inner rotor and the outer rotor, and a housing cover connected to close an opening of the housing main body,
The housing cover is formed with the purge port,
The filter member is attached to the housing cover from the outside.
The oil pump according to claim 1 or 2, characterized in that. The inner rotor and the outer rotor are arranged adjacent to each other in the direction of the axis, and an upstream rotor including a first inner rotor and a first outer rotor, and a downstream rotor including a second inner rotor and a second outer rotor. Including
The housing includes a spacer member interposed between the upstream rotor and the downstream rotor,
The suction port is provided so as to face the upstream rotor,
The discharge port is provided to face the downstream rotor,
The purge port is provided so as to face the upstream rotor,
The spacer member is provided with a communication port that guides oil discharged from the upstream rotor to the downstream rotor.
The oil pump according to any one of claims 1 to 3, wherein: The suction port is provided in the spacer member so as to face the upstream rotor between the upstream rotor and the downstream rotor,
The oil pump according to claim 4. The inner rotor and outer rotor are composed of four leaves and five nodes.
The oil pump according to any one of claims 1 to 5, wherein: The purge port is formed so as to open in a substantially L shape extending in the radial direction passing through the axis and extending in the rotational direction of the inner rotor and outer rotor at the radially outer end thereof.
The oil pump according to any one of claims 1 to 5, wherein:

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