Oil pump device

Abstract

To provide an oil pump device with reduced circulation of impurities together with oil.SOLUTION: An oil pump device comprises: a suction port for sucking oil; a discharge port for discharging oil; a housing including an oil flow passage connecting the suction port and the discharge port; and an oil pump arranged in the oil flow passage and pumping the oil sucked from the suction port toward the discharge port. The oil flow passage includes: a first oil flow passage (49) with one end being open in an outer surface of the housing; a second flow passage (48) connected to the first flow passage (49) at a connection position (P3) different from the position of the opening and extending in a direction different from the first flow passage (49); and an oil sump (49A) formed between the opening of the first flow passage (49) and the connection position (P3). The oil pump device further comprises a blocking member (53) for blocking the opening.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an oil pump device. [Background technology]

[0002] In recent years, efforts have been made to promote the Sustainable Development Goals (2030 Agenda for Sustainable Development, adopted at the United Nations Summit on September 25, 2015, hereafter referred to as "SDGs"). In line with this, technologies that aim to prevent waste generation, reduce waste, and significantly reduce waste generation through the recycling and reuse of products have become known in order to ensure sustainable production and consumption patterns.

[0003] Conventionally, oil pump devices that supply oil to engines mounted on automobiles and the like to lubricate the inside of the engine have been known (see, for example, Patent Document 1). Such oil pump devices include an intake port that draws in oil discharged from the engine, an oil pump that compresses the oil drawn in from the intake port, and a discharge port that discharges the oil compressed by the oil pump toward the engine.

[0004] By using such an oil pump device, the oil that has lubricated the engine returns to the oil pump device and is pumped back to the engine again. In other words, the oil circulates between the engine and the oil pump device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-023634 Summary of the Invention [Problem to be solved by the invention]

[0006] The oil circulating between the engine and the oil pump device may contain impurities (e.g., metal powder) resulting from wear of the engine's sliding parts. These impurities may become trapped in the oil pump, causing malfunctions or damaging the sliding parts. This can result in increased maintenance frequency and a shorter lifespan for the oil pump device itself or the object being lubricated (e.g., the engine).

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an oil pump device that suppresses impurities from circulating together with the oil. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides an oil pump device comprising: a housing in which an intake port for drawing oil, an outlet port for discharging oil, and an oil flow path connecting the intake port and the outlet port are formed; and an oil pump disposed in the oil flow path and pressure-feeding the oil drawn in from the intake port toward the outlet port, wherein the oil flow path includes a first flow path having one end opening to an outer surface of the housing, a second flow path connected to the first flow path at a connection position different from the position of the opening and extending in a direction different from that of the first flow path, and an oil reservoir formed between the opening of the first flow path and the connection position, A plate is provided which is in close contact with the outer surface of the housing so as to close the opening liquid-tightly. The device is characterized by further comprising a blocking member. [Effects of the Invention]

[0009] According to the present invention, it is possible to obtain an oil pump device that suppresses impurities from circulating together with the oil. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an external perspective view of an oil pump device according to an embodiment of the present invention; [Figure 2] FIG. 2 is an exploded perspective view of the oil pump device as seen obliquely from above. [Figure 3] FIG. 2 is an exploded perspective view of the oil pump device as seen obliquely from below. [Figure 4] FIG. 4 is a cross-sectional view of an oil flow path in a motor housing. [Figure 5] FIG. 4 is a cross-sectional view of an oil flow path in a valve housing. DETAILED DESCRIPTION OF THE INVENTION

[0011] An oil pump device 1 according to an embodiment of the present invention will now be described with reference to the drawings.

[0012] Fig. 1 is an external perspective view of an oil pump device 1 according to this embodiment. Fig. 2 is an exploded perspective view of the oil pump device 1 as seen obliquely from above. Fig. 3 is an exploded perspective view of the oil pump device 1 as seen obliquely from below.

[0013] In this specification, the extension direction of the output shaft of the motor 2 and flow paths 46, 47, and 49, which will be described later, is defined as the "up-down direction," the extension direction of a flow path 44, which will be described later, is defined as the "front-rear direction," and the extension direction of flow paths 45, 48, and 50, which will be described later, is defined as the "left-right direction." The extension directions of the output shaft of the motor 2 and the flow paths 45 to 50 are not limited to the example described above.

[0014] The oil pump device 1 according to this embodiment supplies oil pressure to, for example, an engine clutch or a transmission clutch (an example of an object to be lubricated) mounted on an automobile. However, the use of the oil pump device 1 is not limited to this. As shown in FIG. 1, the oil pump device 1 is a so-called "electric oil pump" that includes a motor 2, an oil pump 3, and a relief valve 4.

[0015] The motor 2 generates a driving force for rotating the oil pump 3. The motor 2 mainly comprises, for example, a motor housing 10, a brushless motor 11, and a driver circuit 12. The motor housing 10 accommodates the brushless motor 11 and the driver circuit 12. The brushless motor 11 rotates upon receiving an external supply of power. The driver circuit 12 controls the rotation of the brushless motor 11. The motor 2 is a so-called "electromechanical integrated" motor. The configurations of the brushless motor 5 and the driver circuit 6 are already well known, so a detailed description thereof will be omitted.

[0016] The oil pump 3 compresses and pumps out oil (hereinafter referred to as "pumping") when the driving force of the brushless motor 5 is transmitted to it and it rotates. More specifically, the oil pump 3 is disposed in an oil flow path 43, which will be described later. The oil pump 3 pumps out oil drawn in through an intake port 41, which will be described later, toward an outlet port 42, which will be described later. As shown in FIGS. 2 and 3, the oil pump 3 mainly includes a pump housing 20, an outer rotor 21, and an inner rotor 22.

[0017] The pump housing 20 accommodates an outer rotor 21 and an inner rotor 22. The outer rotor 21 is fixed within the pump housing 20. The inner rotor 22 is attached to the output shaft of the brushless motor 5 and is rotatably accommodated within the outer rotor 21. When the inner rotor 22 rotates due to the driving force of the brushless motor 5, the gap between the outer rotor 21 and the inner rotor 22 changes, compressing the oil. The configuration of the oil pump 3 is already well known, so a detailed description will be omitted.

[0018] When the pressure of the oil pumped by the oil pump 3 is equal to or higher than a threshold value, the relief valve 4 returns a portion of the oil to the upstream side of the oil flow from the oil pump 3. This makes it possible to maintain the pressure of the oil discharged from the discharge port 42 below the threshold value. The relief valve 4 mainly includes a valve housing 30, a spool valve body (not shown), and a coil spring (not shown).

[0019] The valve housing 30 is formed with a valve chamber (not shown) connected to the oil flow path 43 downstream of the oil pump 3 in the oil flow direction, and a return path (not shown) that returns oil from the valve chamber to the upstream side of the oil pump 3 in the oil flow direction. A spool valve element is housed in the valve chamber. A coil spring biases the spool valve element in a direction that closes the valve chamber.

[0020] When the oil pressure in the oil passage 43 reaches or exceeds a threshold value, the spool valve element opens the valve chamber against the biasing force of the coil spring. As a result, the oil that has flowed from the oil passage 43 into the valve chamber returns through the return passage to the upstream side of the oil flow from the oil pump 3. The configuration of the relief valve 4 is already well known, so a detailed description thereof will be omitted.

[0021] The motor housing 10, the pump housing 20, and the valve housing 30 are, for example, die-cast aluminum alloys. The motor housing 10, the pump housing 20, and the valve housing 30 are integrated with bolts or the like. The motor housing 10, the pump housing 20, and the valve housing 30 are examples of housings. However, the housing according to the present invention does not need to be divided as described above.

[0022] FIG. 4 is a cross-sectional view of flow paths 44-46 in the motor housing 10 of FIG. 2. FIG. 5 is a cross-sectional view of flow paths 48-50 in the valve housing 30. As shown in FIGS. 1 to 5, the housing is formed with an intake port 41, a discharge port 42, and an oil flow path 43. The intake port 41 is an opening through which oil discharged from an object to be lubricated, such as an engine, is drawn into the oil pump device 1 (more specifically, into the oil flow path 43). The discharge port 42 is an opening through which oil compressed by the oil pump 3 is discharged to the object to be lubricated, such as an engine. In this embodiment, the intake port 41 is provided in the motor housing 10, and the discharge port 42 is provided in the valve housing 30.

[0023] The oil flow path 43 is a space formed inside the housing through which oil passes. The oil flow path 43 also connects the suction port 41 and the discharge port 42. More specifically, one end of the oil flow path 43 is connected to the suction port 41, and the other end of the oil flow path 43 is connected to the discharge port 42. The oil drawn in through the suction port 41 passes through the oil flow path 43 and is discharged from the discharge port 42. The oil pump 3 is also disposed in the oil flow path 43.

[0024] The oil flow path 43 is formed by combining multiple linearly extending flow paths 44, 45, 46, 47, 48, 49, and 50. The flow paths 44 to 50 extend from the outer surface of the housing toward the interior. The flow paths 44 to 50 are formed, for example, by drilling. Furthermore, adjacent flow paths 44 to 50 communicate with each other. Hereinafter, of the two ends of each of the flow paths 44 to 50, the end on the upstream side of the oil flow will be referred to as the "upstream end," and the end on the downstream side of the oil flow will be referred to as the "downstream end."

[0025] As shown in Fig. 4, flow paths 44 to 46 are formed within the motor housing 10. More specifically, flow path 44 extends in the front-to-rear direction within the motor housing 10. Flow path 45 extends in the left-to-right direction within the motor housing 10. Furthermore, flow path 46 extends in the up-down direction within the motor housing 10. In other words, flow paths 44 to 46 extend in directions perpendicular to each other.

[0026] The upstream end of flow path 44 is connected to suction port 41. As shown in FIGS. 2 and 3, the upstream end of flow path 45 opens to the outer surface (right surface) of motor housing 10. The downstream end of flow path 44 is connected to flow path 45 at connection position P1, which is downstream of the opening of flow path 45 in the oil flow direction. The opening at the upstream end of flow path 45 is closed by closing member 51. An oil reservoir 45A is formed between closing member 51 and connection position P1 of flow path 45. Flow path 45 is an example of a first flow path, and flow path 44 is an example of a second flow path.

[0027] As shown in Fig. 4, the downstream end of flow passage 45 is closed. The upstream end of flow passage 46 is connected to flow passage 45 downstream of connection position P1 in the oil flow direction and upstream of the downstream end of flow passage 45 in the oil flow direction. Furthermore, as shown in Fig. 3, the downstream end of flow passage 46 opens to the outer surface (bottom surface) of the motor housing 10. When the motor housing 10 and the pump housing 20 are joined, the downstream end of flow passage 46 is connected to the oil pump 3.

[0028] As shown in Fig. 5, flow paths 47 to 50 are formed in the valve housing 30. More specifically, flow path 47 extends in the vertical direction within the valve housing 30. Flow path 48 extends in the horizontal direction within the valve housing 30. Flow path 49 extends in the vertical direction within the valve housing 30. Flow path 50 extends in the horizontal direction within the valve housing 30. In other words, flow paths 47, 49 and flow paths 48, 50 extend in directions perpendicular to each other.

[0029] The upstream end of the flow path 47 opens to the outer surface (top surface) of the valve housing 30. When the pump housing 20 and the valve housing 30 are joined, the upstream end of the flow path 47 is connected to the oil pump 3. The upstream end of the flow path 48 opens to the outer surface (left surface) of the valve housing 30. The downstream end of the flow path 47 is connected to the flow path 48 at a connection position P2 that is downstream of the opening of the flow path 48 in the oil flow direction. Furthermore, the opening at the upstream end of the flow path 48 is closed by a closing member 52. An oil reservoir 48A is formed between the closing member 52 of the flow path 48 and the connection position P2. The flow path 48 is an example of a first flow path, and the flow path 47 is an example of a second flow path.

[0030] The downstream end of flow path 48 is connected to the upstream end of flow path 49. The downstream end (lower end) of flow path 49 opens to the outer surface (lower surface) of the valve housing 30. The upstream end of flow path 50 is connected to flow path 49 at a connection position P3 that is upstream (above) of the opening of flow path 49 in the oil flow direction. The opening at the downstream end of flow path 49 is closed by a closing member 53. An oil reservoir 49A is formed between the closing member 53 of flow path 49 and the connection position P3. Flow path 49 is an example of a first flow path, and flow path 50 is an example of a second flow path. The downstream end of flow path 50 is connected to the discharge port 42.

[0031] 4 and 5, oil sucked through intake port 41 flows from flow path 44 into flow path 45 through connection position P1. The oil that passes through flow paths 45 and 46 is compressed by oil pump 3 and sent to flow path 47. The oil that flows into flow path 47 flows into flow path 48 through connection position P2. The oil that passes through flow paths 48 and 49 flows into flow path 50 through connection position P3 and is discharged from discharge port 42.

[0032] On the other hand, almost no oil flows in the oil reservoirs 45A, 48A, and 49A formed between the connection positions P1 to P3 and the blocking members 51 to 53. As a result, impurities tend to accumulate in the oil reservoirs 45A, 48A, and 49A together with the oil.

[0033] The closing member 51 according to this embodiment is composed of a plate 51A and bolts 51B and 51C. The plate 51A is a plate-like member that is in close contact with the outer surface of the motor housing 10 so as to liquid-tightly close the opening at the upstream end of the flow path 45. The plate 51A also has through holes formed in it at a position adjacent to the opening at the upstream end of the flow path 45 (a position different from the opening) that communicate with bolt holes 45B and 45C formed in the outer surface of the motor housing 10. The bolts 51B and 51C pass through the through holes in the plate 51A and are screwed into the bolt holes 45B and 45C. This secures the plate 51A to the outer surface of the motor housing 10.

[0034] Similarly to the closing member 51, the closing members 52 and 53 are composed of plates 52A and 53A and bolts 52B, 52C, 53B, and 53C. That is, the closing members 51, 52, and 53 according to this embodiment close the openings without entering the flow paths 45, 48, and 49. Furthermore, there is no need to form thread grooves or the like in the flow paths 45, 48, and 49 to fix the closing members 51, 52, and 53 according to this embodiment to the housing. Furthermore, the housing and the closing members 51, 52, and 53 are liquid-tightly sealed together by metal-to-metal contact. However, an oil seal may be further interposed between the housing and the closing members 51, 52, and 53.

[0035] Furthermore, a closing member 54 is attached to the valve housing 30. The closing member 54 closes the opening on the base end side of the valve storage chamber. The structure of the closing member 54 is the same as that of the closing member 51, so a repeated description will be omitted.

[0036] According to the above embodiment, for example, the following advantageous effects are achieved.

[0037] According to the above embodiment, impurities mixed in the oil are retained in the oil reservoirs 45A, 48A, and 49A formed between adjacent flow paths 44&45, 47&48, and 49&50, preventing them from flowing downstream of the oil flow path 43. This prevents impurities mixed in the oil circulating between the oil pump device 1 and the object to be lubricated from getting caught in the oil pump 3 and causing malfunctions, or damaging the sliding parts of the oil pump 3 or the object to be lubricated. As a result, the frequency of maintenance of the oil pump device 1 itself or the object to be lubricated is reduced, extending its lifespan. This contributes to ensuring sustainable production and consumption patterns in line with the SDGs, and is expected to reduce waste and defective products.

[0038] Furthermore, according to the above embodiment, the openings of oil reservoirs 45A, 48A, and 49A are closed with closing members 51-53, which are formed of plates 51A-53A and bolts 51B-53C, so the volumes of oil reservoirs 45A, 48A, and 49A can be increased compared to plug-shaped closing members that enter the interiors of flow paths 45, 48, and 49 to close the openings. Furthermore, by closing the openings of oil reservoirs 45A, 48A, and 49A with removable closing members 51-53, impurities that have accumulated in oil reservoirs 45A, 48A, and 49A can be removed.

[0039] Furthermore, according to the above embodiment, oil reservoir 49A is provided at the downstream end of flow path 49, and flow path 50 is connected to connection position P3, which is upstream of oil reservoir 49A in the oil flow direction. This makes it easier for impurities mixed in oil passing through flow path 49 to enter oil reservoir 48A due to inertia. However, oil reservoirs 45A and 48A may also be provided at the upstream ends of flow paths 45 and 48.

[0040] Furthermore, according to the above embodiment, an oil reservoir 49A is provided at the lower end of the flow path 49, and the flow path 50 is connected to a connection position P3 above the oil reservoir 49A. This makes it easier for impurities to remain in the oil reservoir 49A due to gravity. Note that the flow path 49 does not need to extend vertically, and may be inclined relative to the vertical direction as long as it is not horizontal. Furthermore, oil reservoirs 45A and 48A may be provided at the ends of the flow paths 45 and 48 that extend horizontally.

[0041] Furthermore, according to the above embodiment, oil reservoir 45A is provided upstream of oil pump 3 in the oil flow, which prevents impurities generated in the object to be lubricated from entering oil pump 3. This prevents impurities from getting caught between outer rotor 21 and inner rotor 22, which could cause malfunction. However, oil reservoirs 48A and 49A may also be provided downstream of oil pump 3 in the oil flow. Furthermore, oil reservoirs 45A, 48A, and 49A are preferably provided at multiple positions spaced apart in the oil flow.

[0042] The positions of oil reservoirs 45A, 48A, and 49A are not limited to those shown in Figures 4 and 5. In other words, to obtain the effects of the present invention, it is sufficient that an oil reservoir is formed between the opening of the first flow path and the connection position in a portion where a first flow path having one end opening to the outer surface of the housing and a second flow path connected to the first flow path at a connection position different from the opening position and extending in a direction different from that of the first flow path are formed.

[0043] Furthermore, the present invention differs significantly from technologies that use filters to capture impurities in that the oil pump device 1 is operated with impurities mixed in the oil accumulated in the oil reservoirs 45A, 48A, and 49A. This reduces the increase in flow resistance due to filter clogging and reduces the effort required for filter maintenance. However, this does not preclude the installation of a filter between the oil pump device 1 of the present invention and the object to be lubricated.

[0044] The above describes an embodiment of the present invention. However, the present invention is not limited to the above embodiment and includes various modifications. For example, the above embodiment has been described in detail to clearly explain the present invention, and is not necessarily limited to an embodiment including all of the described configurations. Furthermore, it is possible to replace part of the configuration of this embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of this embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of this embodiment with other configurations. [Explanation of symbols]

[0045] 1: Oil pump device 2: Motor 3: Oil pump 4: Relief valve 5: Brushless motor 6: Driver circuit 10: Motor housing (housing) 11: Brushless motor 12: Driver circuit 20: Pump housing (housing) 21: Outer rotor 22: Inner rotor 30: Valve housing (housing) 41: Intake port 42:Discharge port 43: Oil flow path 44~50: Flow path 45A, 48A, 49A: Oil reservoir 45B, 45C: Bolt holes 51, 52, 53, 54: Closure members 51A, 52A, 53A: Plate 51B, 51C, 52B, 52C, 53B, 53C: Bolts

Claims

1. a housing having an intake port for intake of oil, an outlet port for discharge of oil, and an oil flow path connecting the intake port and the outlet port; an oil pump disposed in the oil flow path and pressure-feeding the oil drawn in through the intake port toward the discharge port, The oil flow path a first flow path having one end that opens to an outer surface of the housing; a second flow path connected to the first flow path at a connection position different from the position of the opening and extending in a direction different from that of the first flow path; an oil reservoir formed between the opening of the first flow path and the connection position, The oil pump device further comprises a closing member having a plate that comes into close contact with an outer surface of the housing so as to liquid-tightly close the opening.

2. 2. The oil pump device according to claim 1, 11. The oil pump device according to claim 10, wherein the closing member further includes a bolt that is threaded into a bolt hole formed in the outer surface of the housing to fix the plate to the outer surface of the housing.

3. 2. The oil pump device according to claim 1, the opening is formed at an end of the first flow path on a downstream side in the oil flow direction, The oil pump device according to claim 1, wherein the second flow path is connected to the first flow path at the connection position upstream of the opening in the oil flow direction.

4. 4. The oil pump device according to claim 3, The opening is formed at a lower end of the first flow path that extends in the vertical direction, The oil pump device according to claim 1, wherein the second flow path is connected to the first flow path at the connection position above the opening.

5. 2. The oil pump device according to claim 1, The oil pump device according to claim 1, wherein the first flow path, the second flow path, and the oil reservoir are arranged upstream of the oil pump in the direction of oil flow.

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