JP6413420B2 - Oil pump unit - Google Patents

Description

  The present invention relates to an oil pump unit, and more particularly to an oil pump unit that is rotationally driven by a drive shaft portion.

  Conventionally, an oil pump unit that is rotationally driven by a drive shaft is known (for example, see Patent Document 1).

  Patent Document 1 discloses an oil pump that is rotationally driven directly by a crankshaft of an internal combustion engine or via a chain and a dedicated drive shaft. The oil pump described in Patent Document 1 includes an oil pump case (pump housing) that houses a rotating inner rotor and an outer rotor (oil pump rotor), and a rotor cover that closes an opening of the oil pump case. Moreover, the groove part is formed along the outer peripheral part area | region in the mating surface of an oil pump case and a rotor cover. Then, the oil falling in the internal combustion engine is also supplied to the groove portion and accumulated therein, so that air is sucked into the oil pump case from the outside (crank chamber) through the gap generated in the mating surface. Is prevented.

Japanese Patent Laid-Open No. 10-18828

  In the oil pump described in Patent Document 1, a fastening member for fastening the oil pump case and the rotor cover is provided around the insertion hole of the drive shaft portion in which the drive shaft (or crankshaft) in the rotor cover is inserted. Is considered difficult. In this case, the oil pressure at the discharge port acts on the oil pump case and the rotor cover as the oil pump is driven, and the periphery of the drive shaft insertion hole is likely to be deformed. This region (alignment around the drive shaft portion insertion hole) Surface) is easily formed. For this reason, air is prevented from being sucked from the outer peripheral side of the oil pump case, while air is easily sucked from the periphery of the drive shaft portion insertion hole due to the negative pressure (suction pressure) of the suction port. There is a point.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to prevent air from being sucked from the periphery of the drive shaft insertion hole due to the suction pressure of the suction port. An oil pump unit capable of being suppressed is provided.

In order to achieve the above object, an oil pump unit according to one aspect of the present invention includes a drive shaft portion, an oil pump rotor that is rotationally driven by the drive shaft portion, a pump housing that houses the oil pump rotor, and a drive Including a drive shaft portion insertion hole into which the shaft portion is inserted, and a cover that closes the opening of the pump housing. The drive shaft portion includes a circumferential wall surface portion that protrudes circumferentially from the outer peripheral surface of the drive shaft portion. The outermost peripheral portion of the circumferential wall surface portion is configured to be positioned between the mating surface of the pump housing and the cover and the surface of the cover opposite to the mating surface in the drive shaft portion insertion hole. The drive shaft insertion hole of the cover has a shape in which the inner diameter on the oil pump rotor side is larger than the inner diameter on the side opposite to the oil pump rotor . The “drive shaft portion” in the present invention is not only a single shaft member for taking out a driving force directly or indirectly from the internal combustion engine, but is also attached to the shaft member and rotationally driven integrally with the shaft member. It is a broad concept including things (sprockets, collar members, etc.).

  In the oil pump unit according to one aspect of the present invention, as described above, the drive shaft portion is provided with the circumferential wall surface portion protruding circumferentially from the outer circumferential surface of the drive shaft portion, and the outermost circumferential portion of the circumferential wall surface portion is provided. In the drive shaft portion insertion hole, the pump housing and the cover are configured to be positioned between the mating surface of the pump housing and the cover and the surface of the cover opposite to the mating surface. As a result, part of the oil leaking from the high-pressure part (discharge port) in the oil pump rotor during the rotational drive of the oil pump unit reaches the circumferential wall surface part along the outer peripheral surface of the drive shaft part and rotates. The inner circumferential wall portion is moved radially outward by centrifugal force. And the oil moved radially outward is splashed off in the centrifugal direction (radially outward) from the outermost peripheral portion of the circumferential wall portion located between the mating surface of the cover and the opposite surface, Supplied to the mating surface of the pump housing and cover. Therefore, since this oil can be stored in the gap formed in the portion of the mating surface with the pump housing in the periphery of the drive shaft insertion hole of the cover, from the periphery of the drive shaft insertion hole due to the suction pressure of the suction port. Inhalation of air can be suppressed. In addition, since it is possible to suppress the occurrence of bubble biting (aeration) in the oil sucked from the oil pan through the suction port, it is possible to suppress the deterioration of the performance of the oil pump due to the bubble biting. Can do.

  In the oil pump unit according to the first aspect, the oil once leaked from the high pressure portion in the oil pump rotor is allowed to remain in the oil pump without being wasted to the outside (oil pan at the lower part of the crank chamber). It can be supplied again to the mating surface of the housing and the cover. As a result, the oil supplied again to the mating surfaces can be sucked again from the low pressure part (suction part corresponding to the suction port) in the oil pump rotor. That is, since it is not necessary to newly suck and discharge the leaked oil from the oil pan, it is possible to eliminate unnecessary work due to oil leakage of the oil pump unit.

In the oil pump unit according to the aforementioned aspect, the cover of the drive shaft portion insertion hole, the inner diameter of the oil pump rotor side has a larger shape than the inner diameter of the opposite side of the oil pump rotor. This ensures that can be derived from the outermost peripheral portion of the circumferential wall portion easily splashed skipped oil in a centrifugal direction (radially outward) the mating surface near the oil pump rotor side of the drive shaft unit insertion hole. Therefore, the oil splashed in the centrifugal direction from the outermost peripheral portion of the circumferential wall surface portion is surely supplied and sucked into the gap formed at the mating surface portion with the pump housing in the drive shaft portion insertion hole of the cover. Can do.

  In the oil pump unit according to the above aspect, preferably, the drive shaft portion includes a large-diameter portion provided to extend to the outside from the vicinity of the drive shaft portion insertion hole of the cover, and the circumferential wall surface portion is the large-diameter portion. And a step surface located at the boundary between the portion other than the large-diameter portion. If comprised in this way, using the level | step difference surface located in the boundary of a large diameter part and parts other than a large diameter part, the circumferential wall surface part which protrudes from the outer peripheral surface of a drive shaft part in the shape of a drive shaft part Can be easily provided. In addition, by using this stepped surface, a part of the oil leaking from the high-pressure portion (discharge port) in the oil pump rotor that is rotationally driven can be efficiently moved radially outward by centrifugal force. .

  In the oil pump unit according to the above aspect, the drive shaft portion preferably includes a flange-shaped portion provided in the vicinity of the drive shaft portion insertion hole of the cover, and the circumferential wall surface portion is on the oil pump rotor side of the flange-shaped portion. It is comprised by the side. If comprised in this way, a circumferential wall surface part can be easily provided in a drive shaft part using the hook-shaped part provided in the drive shaft part insertion hole vicinity of the cover. Moreover, the oil leaked from the inside of the oil pump rotor that is rotationally driven can be efficiently moved to the outside in the radial direction by using the centrifugal force by using the hook-shaped portion.

  In the oil pump unit according to the above aspect, preferably, the drive shaft portion is provided on the outer peripheral surface of the drive shaft portion so as to extend from the oil pump rotor side toward the circumferential wall surface portion, and the oil is supplied to the circumferential wall surface portion. It further includes a guiding groove. If comprised in this way, the oil which leaked from the inside of the oil pump rotor in rotation drive can be easily guide | induced to the circumferential wall surface part along the groove part of the outer peripheral surface of the drive shaft part during rotation. In other words, since the amount of oil supplied to the circumferential wall surface portion can be reliably ensured, the oil can be efficiently supplied from the circumferential wall surface portion to the mating surface of the pump housing and the cover.

  In the present application, the following configuration is also conceivable in the oil pump unit according to the above aspect.

(Additional item 1)
That is, in the oil pump unit according to the above aspect, the drive shaft portion includes a crankshaft for taking out drive force from the internal combustion engine.

(Appendix 2)
In the oil pump unit according to the above aspect, the drive shaft insertion hole of the cover has a shape in which the inner diameter gradually increases toward the oil pump rotor side.

(Additional Item 3)
In the oil pump unit according to the above aspect, the drive shaft portion insertion hole of the cover is provided on the opposite side of the oil pump rotor, the first portion having the first inner diameter, and the oil pump rotor of the first portion. And a second portion having a second inner diameter that is larger than the first inner diameter.

(Appendix 4)
In the oil pump unit according to the above aspect, the flange portion of the drive shaft portion is disposed in the drive shaft portion insertion hole.

(Appendix 5)
In the oil pump unit according to the above aspect, the length of the hook-shaped portion is smaller than the length of the drive shaft portion insertion hole in the axial direction of the drive shaft portion.

  Further, in the present application, apart from the oil pump unit according to the above one aspect, the following other configurations are also conceivable.

(Appendix 6)
That is, an internal combustion engine according to another aspect of the present invention includes an internal combustion engine body including a crankshaft, and an oil pump that is driven by the crankshaft and supplies oil to the internal combustion engine body. The oil pump is rotated by the crankshaft. An oil pump rotor to be driven; a pump housing in which the oil pump rotor is accommodated; and a cover having a shaft insertion hole into which the crankshaft is inserted and closing an opening of the pump housing. A circumferential wall surface portion projecting circumferentially from the outer circumferential surface, and the outermost circumferential portion of the circumferential wall surface portion is located on the opposite side of the mating surface between the pump housing and the cover in the shaft insertion hole. It is comprised so that it may be located between the surfaces of a cover.

  According to the present invention, as described above, it is possible to provide an oil pump unit capable of suppressing air from being sucked from the periphery of the drive shaft portion insertion hole due to the suction pressure of the suction port.

1 is a perspective view schematically showing an engine equipped with an oil pump according to a first embodiment of the present invention. 1 is an exploded perspective view showing a configuration around an oil pump according to a first embodiment of the present invention. It is sectional drawing which showed the internal structure of the oil pump by 1st Embodiment of this invention. It is sectional drawing which showed the internal structure of the oil pump by 1st Embodiment of this invention. It is the perspective view which showed the crankshaft which drives the oil pump by 1st Embodiment of this invention. It is sectional drawing which showed the internal structure of the oil pump by the modification of 1st Embodiment of this invention. It is the perspective view which showed the crankshaft which drives the oil pump by the modification of 1st Embodiment of this invention. It is sectional drawing which showed the internal structure of the oil pump by 2nd Embodiment of this invention. It is sectional drawing which showed the internal structure of the oil pump by 3rd Embodiment of this invention. It is the perspective view which showed the crankshaft which drives the oil pump by 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
First, with reference to FIGS. 1-5, the structure of the oil pump 100 by 1st Embodiment of this invention is demonstrated. In the following description, it is assumed that the crankshaft 90 extends along the X axis and the piston 82 reciprocates along the Z axis when the engine 80 is used as a reference.

  The oil pump 100 according to the first embodiment of the present invention is mounted on an automobile (not shown) provided with an engine 80 as shown in FIG. The oil pump 100 has a function of pumping up oil (lubricating oil) 1 in the oil pan 81 and supplying (pumping) it to a movable part (sliding part) around the piston 82 and the crankshaft 90. The crankshaft 90 is an example of the “drive shaft portion” in the present invention. The configuration in which the oil pump 100 is rotationally driven by the crankshaft 90 in the engine 80 is an example of the “oil pump unit” in the present invention.

  As shown in FIG. 2, the internal gear type oil pump 100 includes an aluminum alloy casing portion 10, an inner rotor 20 and an outer rotor 30 that are accommodated in the casing portion 10 and rotatably provided in the casing portion 10. A pump cover 40 made of aluminum alloy that seals the opening 15 (see FIG. 4) on the X1 side of the casing part 10 from the inside of the engine 80 (crank chamber 85 (see FIG. 1) side), and the casing part 10 And an annular oil seal 50 fitted into the opening 16 (see FIG. 4) on the X2 side. The casing portion 10 is configured by a part of a chain cover 10a that covers the side surface (X1 side) of the engine 80. Further, the shaft insertion hole 22 that becomes the rotation center A (X axis) of the inner rotor 20 is configured such that an end region on the X2 side of the crankshaft 90 (a rotor insertion shaft portion 92 described later) is penetrated. The inner rotor 20 is configured to directly transmit the driving force of the engine 80 (see FIG. 1). The inner rotor 20 and the outer rotor 30 are examples of the “oil pump rotor” in the present invention. The casing 10 and the pump cover 40 are examples of the “pump housing” and the “cover” of the present invention, respectively.

  Here, as shown in FIG. 3, the rotation center A of the inner rotor 20 (the axis of the crankshaft 90) is eccentric by a certain amount in the direction of the arrow Z <b> 2 with respect to the rotation center B of the outer rotor 30. When the crankshaft 90 and the inner rotor 20 are rotated in the arrow R1 direction (clockwise direction), the outer rotor 30 is rotated with a slight delay in the same direction. At the time of rotation, in a place where the distance between the inner rotor 20 and the outer rotor 30 is short (Z2 side region), the outer teeth 21 of the inner rotor 20 and the inner teeth 31 of the outer rotor 30 mesh with each other, while the longer distance (Z1 side region). ), The inner rotor 20 has one fewer tooth, so that a gap (volume chamber U) is gradually formed between the inner rotor 20 and the outer rotor 30. Further, the volume chamber U expands or contracts with the rotational movement in the direction of the arrow R1, and a pump function is created. Therefore, the oil 1 (see FIG. 1) is sucked into the volume chamber U in accordance with the volume change (enlargement) from the minimum value to the maximum value of the volume chamber U, and the volume change (reduction) from the maximum value of the volume chamber U to the minimum value. ), The oil 1 held in the volume chamber U is discharged from the volume chamber U to the outside. The shaft insertion hole 22 provided at the rotation center A of the inner rotor 20 has an oval hole shape. Further, the shaft insertion hole 22 has an opening cross-sectional shape that is slightly larger than a rotor insertion shaft portion 92 described later of the crankshaft 90.

  As shown in FIGS. 1 and 2, the oil pump 100 is provided with a suction oil passage 11 for sucking the oil 1 and a discharge oil passage 12 for discharging the oil 1. The suction oil passage 11 and the discharge oil passage 12 are formed with concave shapes on the inner surfaces of the casing portion 10 and the pump cover 40 (opposing surfaces on the side where the inner rotor 20 and the outer rotor 30 are rotatably sandwiched). Further, the suction oil passage 11 and the discharge oil passage 12 are each formed with a predetermined flow path shape in a state where the pump cover 40 is attached to the casing portion 10. 3, the suction port 11a at the tip of the suction oil passage 11 and the discharge port 12a at the tip of the discharge oil passage 12 are disposed in the meshing region of the inner rotor 20 and the outer rotor 30, as indicated by a two-dot chain line in FIG. Yes.

  Therefore, as shown in FIG. 1, the oil pump 100 sucks the oil 1 from the oil pan 81 through the suction oil passage 11, and then generates a predetermined hydraulic pressure along with the volume reduction of the volume chamber U (see FIG. 3). It has a function of discharging from the discharge oil passage 12 in a state where The oil 1 is pumped toward the oil filter 83 via the discharge path 2. In addition, the oil 1 from which foreign matter has been removed through the oil filter 83 is supplied to a movable part (sliding part) in the engine 80. The oil 1 supplied into the engine 80 is returned to the oil pan 81 below the crank chamber 85 through the return oil passage 3.

  As shown in FIG. 2, the pump cover 40 is provided with a shaft insertion hole 41 for inserting an end region (a rotor insertion shaft portion 92 described later) of the crankshaft 90 on the X2 side. The shaft insertion hole 41 penetrates along the X axis from the mating surface 42 of the casing portion 10 and the pump cover 40 to the surface 43 of the pump cover 40 opposite to the mating surface 42. The shaft insertion hole 41 is an example of the “drive shaft portion insertion hole” in the present invention.

  The crankshaft 90 is configured by connecting a crankpin (not shown) and a balance weight to a crank journal 91. Further, a rotor insertion shaft portion 92 that is inserted into the shaft insertion hole 22 of the inner rotor 20 is connected to an end portion of the crank journal 91 on the X2 side. The rotor insertion shaft portion 92 has a cross section in which D cut processing is performed on both sides of the outer peripheral surface 92a. Further, a shaft end portion 93 that is fitted with a belt pulley 84 (see FIG. 4) and is fixed by a fastening member 60 (see FIG. 4) is connected to the end portion on the X2 side of the rotor insertion shaft portion 92. . The shaft end portion 93 has a circular cross section having an outer diameter that is a length between a pair of D-cut surfaces 92b of the rotor insertion shaft portion 92 (see FIG. 3). Further, in the state where the belt pulley 84 is fixed to the shaft end portion 93, the oil seal 50 in which the outer peripheral portion (outer surface) of the boss portion 84 a of the belt pulley 84 is fitted into the opening portion 16 on the X2 side of the casing portion 10. Is slidably inserted into the housing. The crank journal 91 is an example of the “large diameter portion” in the present invention. The rotor insertion shaft portion 92 is an example of the “portion other than the large diameter portion” in the present invention.

  As shown in FIG. 4, with the inner rotor 20 and the outer rotor 30 housed in the casing portion 10, the pump cover 40 is attached to the casing portion 10 by the fastening member 70 along the arrow X2 direction. As shown in FIG. 3, the outer peripheral portion of the pump cover 40 and the outer peripheral portion of the casing portion 10 (see FIG. 4) corresponding thereto are fastened to each other by the plurality of fastening members 70. As shown in FIG. 4, the crankshaft 90 is inserted into the shaft insertion hole 41 of the pump cover 40 in the order of the shaft end portion 93 and the rotor insertion shaft portion 92, and the shaft end portion 93 is fitted into the oil seal 50. Then, the rotor insertion shaft portion 92 is inserted into the shaft insertion hole 22 of the inner rotor 20. As the crankshaft 90 rotates in the direction of arrow R1, the inner rotor 20 and the outer rotor 30 are driven to rotate, whereby the oil 1 sucked from the suction port 11a (see FIG. 3) is discharged from the discharge port 12a (see FIG. 3). The At this time, as shown in FIGS. 3 and 4, due to the structure of the oil pump 100, a part of the oil 1 flowing through the volume chamber U and the discharge port 12 a is formed between the rotor insertion shaft portion 92 and the shaft insertion hole 22. Leaking toward the gap S.

  Here, in the first embodiment, as shown in FIGS. 4 and 5, the crankshaft 90 has a circumferentially projecting circumferential shape (circumferential shape) radially outward from the outer peripheral surface 92 a of the rotor insertion shaft portion 92. A wall surface 94 is provided. That is, the crank journal 91 having the outer diameter D1 is increased in diameter by the circumferential wall surface portion 94 than the rotor insertion shaft portion 92 having the outer diameter D2 (the outer diameter D1> the outer diameter D2). Further, the circumferential wall surface portion 94 is constituted by a step surface 94 a located at the boundary between the rotor insertion shaft portion 92 and the crank journal 91. The step surface 94a extends linearly from the rotor insertion shaft portion 92 toward the crank journal 91 with a certain inclination angle with respect to the X axis. As shown in FIG. 4, in the state where the oil pump 100 is incorporated in the engine 80, the outermost peripheral portion 94 b (portion equal to the outer diameter D <b> 1 of the crank journal 91) of the circumferential wall surface portion 94 is In the shaft insertion hole 41, it is located between the mating surface 42 (X2 side) of the casing portion 10 and the pump cover 40 and the surface 43 of the pump cover 40 on the opposite side (X1 side) of the mating surface 42. It is configured.

  As shown in FIG. 4, the shaft insertion hole 41 of the pump cover 40 in which the circumferential wall surface portion 94 is arranged has an inner diameter d2 on the inner rotor 20 side (X2 side) opposite to the inner rotor 20 (X1 side). The inner diameter d1 is larger (the inner diameter d2> the inner diameter d1). That is, the shaft insertion hole 41 gradually increases in inner diameter from the inner diameter d1 to the inner diameter d2 along the thickness direction (X-axis direction) from the crank chamber 85 side (X1 side) toward the inside of the oil pump 100 (a divergent shape). The inner surface 41a is widened. The inner diameter d1 and the inner diameter d2 are both larger than the outer diameter D1 of the outermost peripheral portion 94b of the circumferential wall portion 94.

  In the first embodiment, as shown in FIGS. 3 to 5, the crankshaft 90 has oil 1 on the outer peripheral surface 92 a except for the pair of D cut surfaces 92 b of the rotor insertion shaft portion 92. A plurality (total 12) of groove portions 95 leading to the portion 94 are formed. Further, each of the groove portions 95 has a starting portion (rotor insertion shaft portion) of the circumferential wall surface portion 94 through a region corresponding to the shaft insertion hole 22 from a position slightly closer to the oil seal 50 than the side end surface on the X2 side of the inner rotor 20. (End portion on the X1 side of 92) is provided so as to extend linearly along the X-axis.

  As a result, the oil 1 leaking from the discharge port 12a or the like to the vicinity of the outer peripheral surface 92a including the D-cut surface 92b of the rotor insertion shaft portion 92 while the oil pump 100 is driven to rotate, as shown in FIG. It flows into the clearance S from the vicinity of the side end surface on the X2 side, flows through the outer peripheral surface 92a of the rotor insertion shaft portion 92 and the groove portion 95, and moves to the circumferential wall surface portion 94 along the arrow X1 direction. And the oil 1 which distribute | circulated the outer peripheral surface 92a and the inside of the groove part 95 is a centrifugal direction (radial direction outer side of the circumferential wall surface part 94) along the level | step difference surface 94a as the circumferential wall surface part 94 rotates. It is moved further. Then, the outermost peripheral portion 94b of the circumferential wall surface portion 94b located between the mating surface 42 and the surface 43 of the pump cover 40 is further splashed outward by centrifugal force. The oil 1 splashed outward is transferred from the surface 43 side to the mating surface 42 side having an enlarged inner diameter along the inner side surface 41a formed of the inclined surface of the shaft insertion hole 41 and the casing portion 10. To the mating surface 42 of the pump cover 40.

  Here, the casing part 10 and the pump cover 40 are fastened to each other by a fastening member 70. However, as the oil pump 100 is driven, the hydraulic pressure of the discharge port 12a acts on both the casing part 10 and the pump cover 40 to Slightly deform. Further, since the fastening member 70 (see FIG. 3) is not provided around the shaft insertion hole 41, the deformation of the pump cover 40 is relatively large with respect to the outer peripheral portion where the fastening member 70 is fastened. Therefore, a slight gap also occurs on the mating surface 42 between the casing portion 10 and the pump cover 40. Further, the oil 1 leaking from the discharge port 12a (discharge oil passage 12) leaks to the crank chamber 85 side through a gap generated in the mating surface 42. At the same time, in the region on the suction port 11a side, the air (air) in the crank chamber 85 is caused by the negative pressure of the suction port 11a, and the gap S between the rotor insertion shaft portion 92 and the shaft insertion hole 22 or the mating surface. The air is drawn into the suction port 11a through a gap generated in 42.

  However, in the first embodiment, the oil 1 leaking from the discharge port 12a is configured to be supplied to the mating surface 42 where a gap is likely to be generated using the rotational motion of the circumferential wall surface portion 94. As a result, the oil 1 is sucked and filled in the gap generated in the mating surface 42, so that the air (air) in the crank chamber 85 passes through the gap generated in the mating surface 42 to the suction port 11a. Will not be inhaled. That is, the air seal function for the crank chamber 85 is achieved by the oil 1 filled in the gap between the mating surfaces 42. The oil 1 filled in the gap between the mating surfaces 42 is again sucked into the suction port 11a due to the negative pressure of the suction port 11a, but the new oil 1 replenished by the rotation of the circumferential wall surface portion 94 is combined. It is efficiently supplied to the gap between the surfaces 42. That is, it is not necessary to newly suck out and discharge the leaked oil 1 from the oil pan 81. In the oil pump 100, the internal circulation of the leaked oil 1 is achieved, thereby achieving an air seal function and recovery of wasted work. The oil pump 100 in the first embodiment is configured as described above.

  In the first embodiment, the following effects can be obtained.

  That is, in the first embodiment, as described above, the crankshaft 90 is provided with the circumferential wall surface portion 94 that protrudes circumferentially from the outer circumferential surface 92a of the crankshaft 90, and the outermost circumferential portion 94b of the circumferential wall surface portion 94 includes In the shaft insertion hole 41, it is comprised so that it may be located between the mating surface 42 of the casing part 10 and the pump cover 40, and the surface 43 of the pump cover 40 on the opposite side to the mating surface 42. Accordingly, the oil 1 leaked from the discharge port 12a through the clearance S between the shaft insertion hole 22 of the inner rotor 20 and the outer peripheral surface 92a of the rotor insertion shaft portion 92 during the rotation of the oil pump 100 is caused to be a circumferential wall surface. While reaching the portion 94, it is moved outward in the radial direction by centrifugal force in the rotating circumferential wall surface portion 94. Then, the oil 1 moved radially outwardly jumps in the centrifugal direction (radially outward) from the outermost peripheral portion 94b of the circumferential wall portion 94 located between the mating surface 42 and the surface 43 of the pump cover 40. Then, it is supplied to the mating surface 42 of the casing portion 10 and the pump cover 40 through the inner side surface 41 a of the shaft insertion hole 41. Therefore, the oil 1 can be stored in a gap generated in the portion of the mating surface 42 with the casing portion 10 around the shaft insertion hole 41 of the pump cover 40, and thus is caused by the suction pressure (negative pressure) of the suction port 11a. Thus, it is possible to suppress air from being sucked in from the periphery of the shaft insertion hole 41. Further, since it is possible to suppress the occurrence of bubble biting (aeration) in the oil 1 sucked from the oil pan 81 through the suction port 11a, the performance of the oil pump 100 is reduced due to the bubble biting. Can be suppressed.

  Further, in the first embodiment, the oil 1 once leaked from the high pressure portion (discharge port 12a) in the inner rotor 20 is allowed to remain in the oil pump 100 without being wasted to the oil pan 81 below the crank chamber 85. It can be supplied again to the mating surface 42 of the casing part 10 and the pump cover 40. Thereby, the oil 1 supplied again to the mating surface 42 can be sucked again from the low-pressure (suction) portion (the part corresponding to the suction port 11a) in the inner rotor 20. That is, since it is not necessary to newly suck and discharge the oil amount corresponding to the leaked oil 1 from the oil pan 81, it is possible to eliminate unnecessary work due to oil leakage of the oil pump 100.

  In the first embodiment, the shaft insertion hole 41 of the pump cover 40 is formed so that the inner diameter d2 on the inner rotor 20 side (X2 side) is larger than the inner diameter d1 on the opposite side (X1 side) from the inner rotor 20. Configure. Accordingly, the oil 1 splashed in the centrifugal direction (radially outward) from the outermost peripheral portion 94b of the circumferential wall surface portion 94 can be easily guided to the vicinity of the mating surface 42 on the inner rotor 20 side in the shaft insertion hole 41. Therefore, the oil 1 splashed in the centrifugal direction from the outermost peripheral portion 94b of the circumferential wall portion 94 is reliably inserted into the gap formed in the portion of the mating surface 42 with the casing portion 10 in the shaft insertion hole 41 of the pump cover 40. Can be fed and sucked.

  In the first embodiment, the crankshaft 90 extends from the rotor insertion shaft portion 92 inserted (penetrated) into the inner rotor 20 and the vicinity of the shaft insertion hole 41 of the pump cover 40 to the outside (the crank chamber 85 of the engine 80). A crank journal 91 is provided. A circumferential wall surface portion 94 is configured by a step surface 94 a located at the boundary between the crank journal 91 and the rotor insertion shaft portion 92. As a result, the circumferential wall surface 94 projecting circumferentially from the outer circumferential surface 92a of the rotor insertion shaft portion 92 is formed on the crankshaft 90 using the step surface 94a located at the boundary between the crank journal 91 and the rotor insertion shaft portion 92. Can be easily provided. In addition, the oil 1 leaked from the discharge port 12a through the gap S between the shaft insertion hole 22 of the inner rotor 20 and the outer peripheral surface 92a of the rotor insertion shaft portion 92 is removed from the discharge port 12a by centrifugal force. Thus, it can be efficiently moved outward in the radial direction.

  In the first embodiment, the plurality of groove portions 95 that are provided so as to extend from the inner rotor 20 side (X2 side) toward the circumferential wall surface portion 94 (X1 side) and guide the oil 1 to the circumferential wall surface portion 94 are cranked. It is provided on the outer peripheral surface 92a of the shaft 90 (rotor insertion shaft portion 92). As a result, the oil 1 leaked from the discharge port 12a through the gap S between the shaft insertion hole 22 of the inner rotor 20 and the outer peripheral surface 92a of the rotor insertion shaft portion 92 is removed from the outer periphery of the rotating rotor insertion shaft portion 92. It can be easily guided to the circumferential wall surface portion 94 (step surface 94a) through the groove portion 95 of the surface 92a. That is, since the supply amount of the oil 1 to the circumferential wall surface portion 94 can be surely ensured, the circumferential wall surface portion 94 (step surface 94a) is also efficiently applied to the mating surface 42 of the casing portion 10 and the pump cover 40. Oil 1 can be supplied well.

(Modification of the first embodiment)
Next, a modification of the first embodiment of the present invention will be described with reference to FIGS. In the modification of the first embodiment, an example in which the crankshaft 190 is configured so that the circumferential wall surface portion 194 extends toward the crank journal 91 from a position where the circumferential wall surface portion 194 slightly enters the shaft insertion hole 22 of the inner rotor 20 will be described. The crankshaft 190 is an example of the “drive shaft portion” in the present invention. In the figure, components similar to those in the first embodiment are denoted by the same reference numerals as those in the first embodiment.

  The oil pump 105 in the modification of the first embodiment is rotationally driven by a crankshaft 190 in the engine 80 as shown in FIG. Further, as shown in FIG. 7, the crankshaft 190 is provided between the crank journal 91 and the rotor insertion shaft portion 92, and the step of the circumferential wall portion 94 in the crankshaft 90 (see FIG. 5) of the first embodiment. A circumferential wall surface portion 194 (step surface 194a) having a larger surface area than the surface 94a (see FIG. 5) is formed. The configuration in which the oil pump 105 is rotationally driven by the crankshaft 190 in the engine 80 is an example of the “oil pump unit” in the present invention.

  As shown in FIG. 6, when the oil pump 105 is incorporated, the end portion on the X2 side of the step surface 194 a of the circumferential wall surface portion 194 is slightly in the opening portion on the X1 side of the shaft insertion hole 22 of the inner rotor 20. Starting from the inserted position, the shaft insertion hole 41 extends obliquely toward the crank journal 91. Also in this case, the outermost peripheral portion 194 b of the circumferential wall surface portion 194 (portion equal to the outer diameter D 2 of the crank journal 91) is within the shaft insertion hole 41 of the pump cover 40 and the casing portion 10 and the pump cover 40. It is comprised so that it may be located between the mating surface 42 (X2 side) of this and the surface 43 (X1 side) of the pump cover 40. FIG.

  As shown in FIG. 7, each of the plurality of grooves 195 formed on the outer peripheral surface 92 a of the rotor insertion shaft portion 92 has a step surface corresponding to the amount that the starting point of the step surface 194 a slightly enters the shaft insertion hole 22. It also has an end 195a formed on 194a. As a result, as shown in FIG. 6, the oil 1 leaked from the discharge port 12 a or the like to the vicinity of the outer peripheral surface 92 a of the rotor insertion shaft portion 92 while the oil pump 105 is driven to rotate is near the side end surface on the X2 side of the inner rotor 20. Then, it flows into the clearance S, flows through the groove portion 195 of the rotor insertion shaft portion 92, and moves along the arrow X1 direction to the circumferential wall surface portion 194. And the oil 1 which distribute | circulated the groove part 195 is further moved to the centrifugal direction (radial direction outer side of the circumferential wall surface part 194) along the level | step difference surface 194a as the circumferential wall surface part 194 rotates, The outer peripheral portion 194b is further jumped outward by centrifugal force. Then, the oil 1 splashed outward is moved along the inclined surface from the surface 43 side to the mating surface 42 side having an enlarged inner diameter along the inner surface of the shaft insertion hole 41, and the casing 10 and the pump It is supplied to the mating surface 42 with the cover 40.

  The oil pump 105 including the structure around the inner rotor 20 is configured in the same manner as the oil pump 100 of the first embodiment except that the position of the step surface 194a is different.

  In the modification of the first embodiment, as described above, the end portion on the X2 side of the step surface 194a of the circumferential wall surface portion 194 is slightly inserted into the opening portion on the X1 side of the shaft insertion hole 22 of the inner rotor 20. The crankshaft 190 is configured to be assembled to the inner rotor 20. As a result, the oil 1 that flows through the groove portion 195 of the rotor insertion shaft portion 92 and moves along the direction of the arrow X1 to the circumferential wall surface portion 194 more quickly reaches the circumferential wall surface portion 194 and is rotated. It can be moved in the centrifugal direction along the step surface 194a.

  In the modification of the first embodiment, each of the plurality of groove portions 195 is configured to have an end portion 195a formed not only on the outer peripheral surface 92a of the rotor insertion shaft portion 92 but also on the step surface 194a. Accordingly, the oil 1 that flows through the groove portion 195 of the rotor insertion shaft portion 92 and moves along the arrow X1 direction to the circumferential wall surface portion 194 is surely made to reach the step surface 194a of the circumferential wall surface portion 194. Can do. The remaining effects of the modification of the first embodiment are similar to those of the aforementioned first embodiment.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. 3 and FIG. In the second embodiment, an example will be described in which a crankshaft 290 is configured by providing a flange-shaped portion 294 that protrudes radially outward at a boundary portion between the crank journal 291 and the rotor insertion shaft portion 92. The crankshaft 290 is an example of the “drive shaft portion” in the present invention. In the drawing, the same reference numerals as those in the first embodiment are attached to the same components as those in the first embodiment.

  The oil pump 200 in the second embodiment is rotationally driven by a crankshaft 290 in the engine 80 as shown in FIG. Further, the crankshaft 290 has a hook-shaped portion 294 formed between the crank journal 291 and the rotor insertion shaft portion 92. The outer diameter D1 of the crank journal 291 and the outer diameter D2 of the rotor insertion shaft portion 92 are substantially equal. Further, the hook-shaped portion 294 is formed to protrude perpendicularly to the outer peripheral surface 92a radially outward from the outer peripheral surface 92a of the rotor insertion shaft portion 92. The hook-shaped portion 294 includes the crank journal 291 and the rotor. The outer diameter D <b> 3 is larger than the insertion shaft portion 92. Further, the flange portion 294 is configured by a circumferential (annular) vertical side surface 294 a located in a boundary region between the rotor insertion shaft portion 92 and the crank journal 291. The configuration in which the oil pump 200 is rotationally driven by the crankshaft 290 in the engine 80 is an example of the “oil pump unit” in the present invention.

  As shown in FIG. 8, the outermost peripheral portion 294 b (portion having the outer diameter D <b> 3) of the flange-shaped portion 294 is in the shaft insertion hole 241 of the pump cover 240 in the state where the oil pump 200 is incorporated. It is configured to be positioned between the mating surface 242 (X2 side) of the portion 10 and the pump cover 240 and the surface 243 of the pump cover 240 on the opposite side (X1 side) of the mating surface 242. The flange-shaped portion 294 is configured such that the side surface 294c on the X1 side does not protrude outward (on the crank chamber 85 side) from the surface 243 of the pump cover 240. The pump cover 240 is an example of the “cover” in the present invention. The shaft insertion hole 241 is an example of the “drive shaft part insertion hole” in the present invention. The surface 243 is an example of the “surface of the cover opposite to the mating surface” in the present invention.

  Further, in the second embodiment, the shaft insertion hole 241 of the pump cover 240 is provided on the opposite side (X1 side) from the inner rotor 20, and a small diameter portion 241a having an inner diameter d1 and the inner rotor 20 side (X2) of the small diameter portion 241a. And a large-diameter portion 241b having an inner diameter d2 larger than the inner diameter d1. That is, the shaft insertion hole 241 increases in a stepwise manner from the inner diameter d1 to the inner diameter d2 along the thickness direction (X-axis direction) from the crank chamber 85 side (X1 side) toward the inside of the oil pump 200. It is configured. In addition, the large-diameter portion 241b is formed to be slightly larger than the small-diameter portion 241a, so that a concave portion 241c (notch portion) is formed in the circumferential shape on the mating surface 242.

  As a result, the oil 1 leaking from the discharge port 12a or the like to the vicinity of the outer peripheral surface 92a of the rotor insertion shaft portion 92 while the oil pump 200 is driven to rotate flows into the gap S from the vicinity of the side end surface of the inner rotor 20 on the X2 side. It moves through the outer peripheral surface 92a of the insertion shaft portion 92 and the groove portion 95 and is moved along the arrow X1 direction to the bowl-shaped portion 294. Then, the oil 1 that has circulated in the outer peripheral surface 92a and the groove portion 95 is further moved along the side surface 294a in the centrifugal direction (outside in the radial direction of the hook-shaped portion 294) as the hook-shaped portion 294 is rotated. The outermost peripheral portion 294b is further spattered outward by centrifugal force. Then, the oil 1 splashed outwardly accumulates in the large-diameter portion 241b (concave portion 241c) having a concave shape (notch shape) along the small-diameter portion 241a of the shaft insertion hole 241 from the surface 243 side. Then, the oil 1 collected in the large diameter portion 241b is supplied to the mating surface 242 between the casing portion 10 and the pump cover 240.

  The oil pump 200 including the structure around the inner rotor 20 is configured in the same manner as the oil pump 100 of the first embodiment except that the crankshaft 290 having the hook-shaped portion 294 is rotationally driven.

  In the second embodiment, as described above, the crankshaft 290 includes the hook-shaped portion 294 provided in the vicinity of the pump cover 40 shaft insertion hole 41, and the hook-shaped portion 294 is located on the inner rotor 20 side of the hook-shaped portion 294. It is comprised by the side surface 294a. Accordingly, the flange 294 that protrudes circumferentially from the outer peripheral surface 92a of the rotor insertion shaft portion 92 is easily provided on the crankshaft 290 using the side surface 294a provided near the shaft insertion hole 241 of the pump cover 240. be able to. Further, the oil 1 leaked from the discharge port 12a through the shaft insertion hole 22 of the inner rotor 20 (near the outer peripheral surface 92a of the rotor insertion shaft portion 92) is centrifuged by using the side surface 294a (the flange portion 294). It can be efficiently moved radially outward by force. The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. 3 and FIGS. In the third embodiment, an example will be described in which a circumferential wall surface 304 is provided on a sprocket 301 that is mounted coaxially with a crank journal 391 on a crankshaft 390 and driven to rotate. The crankshaft 390 and the sprocket 301 are an example of the “drive shaft portion” in the present invention. In the drawing, the same reference numerals as those in the second embodiment are attached to the same components as those in the second embodiment.

  The oil pump 300 in the third embodiment is rotationally driven by a crankshaft 390 in the engine 80 as shown in FIG. Here, the crankshaft 390 is mounted on the crank journal 391 by being coaxially fitted with a sprocket 301 for transmitting a driving force to the timing chain 86. The outer diameter of the shaft end portion 393 to which the belt pulley 84 is fitted is equal to the outer diameter of the crank journal 391. The sprocket 301 is configured by integrating a gear portion 303 that meshes with the timing chain 86 into a hollow shaft-shaped body portion 302. In the state where the oil pump 300 is assembled, the end portion region on the X2 side of the trunk portion 302 of the sprocket 301 passes through the shaft insertion hole 241 of the pump cover 240 and the shaft insertion hole 22 of the inner rotor 20 (FIG. 3). To the position where it is reliably engaged. The configuration in which the oil pump 300 is rotationally driven by the crankshaft 390 in the engine 80 is an example of the “oil pump unit” in the present invention.

  Here, in the third embodiment, a circumferential wall surface 304 is integrally formed on the body 302 of the sprocket 301. The circumferential wall surface portion 304 has a step surface 304a that protrudes perpendicularly to the outer peripheral surface 302a radially outward from the outer peripheral surface 302a of the trunk portion 302. The outermost peripheral portion 304b (the portion having the outer diameter D3) of the circumferential wall surface portion 304 that is the outermost peripheral portion in the radial direction of the step surface 304a is within the shaft insertion hole 241 of the pump cover 240 and the casing portion 10 and the pump. It is configured to be positioned between the mating surface 242 (X2 side) with the cover 240 and the opposite surface 243. Further, the body 302 has an outer peripheral portion 302b having the same outer diameter D3 as the outermost peripheral portion 304b of the step surface 304a (circumferential wall surface portion 304) and extending in the arrow X1 direction. The outer peripheral portion 302b extends through the shaft insertion hole 241 in the arrow X1 direction and reaches the gear portion 303. The outer peripheral portion 302b is an example of the “large diameter portion” in the present invention. Moreover, the part which has the outer peripheral surface 302a in the trunk | drum 302 is an example of the "part other than a large diameter part" of this invention.

  In the third embodiment, as shown in FIG. 10, the sprocket 301 is formed with a plurality of groove portions 305 that guide the oil 1 to the circumferential wall surface portion 304 in a part of the outer peripheral surface 302 a of the trunk portion 302. . Further, the groove portion 305 extends from the position slightly closer to the oil seal 50 (see FIG. 9) side than the side end surface on the X2 side of the inner rotor 20 to the starting point portion (the end portion on the X1 side of the body portion 302) of the circumferential wall surface portion 304. It extends linearly along the X axis.

  As a result, the oil 1 leaking from the discharge port 12a or the like to the vicinity of the outer peripheral surface 302a of the trunk portion 302 while the oil pump 300 is driven to rotate flows into the gap S from the vicinity of the side end surface on the X2 side of the inner rotor 20, and Circulates in the outer peripheral surface 302a and the groove portion 305 and moves to the circumferential wall surface portion 304 along the arrow X1 direction. The oil 1 is further moved in the centrifugal direction (radially outside the circumferential wall surface 304) along the step surface 304a as the circumferential wall surface 304 is rotated, and the centrifugal force in the outermost circumferential portion 304b. As a result, it is splashed to the shaft insertion hole 241 and finally supplied to the mating surface 242.

  The oil pump 300 including the structure around the inner rotor 20 is the same as that of the second embodiment except that the sprocket 301 having the circumferential wall portion 304 is rotationally driven by a crankshaft 390 that is coaxially mounted. The configuration is the same as that of the pump 200 (see FIG. 8).

  In the third embodiment, as described above, the sprocket 301 is mounted on the crank journal 391 in the crankshaft 390, and the circumferential wall surface 304 is provided on the body 302 of the sprocket 301. Accordingly, the outer diameter of the crank journal 391 is changed (increased), unlike the case where the outer peripheral diameter of the crank journal 391 is increased to provide the circumferential wall surface portion 94 (see FIG. 5) and the flange-shaped portion 294 (see FIG. 7). By arranging the shape (outer diameter) on the sprocket 301 side without making it, the peripheral wall surface portion 304 for splashing the oil 1 can be easily provided in the oil pump 300. Further, since the circumferential wall surface portion 304 can be provided by effectively using the sprocket 301 that transmits the driving force to the timing chain 86, the effect of suppressing the bubble biting into the oil 1 by the design change of the sprocket 301 is easily achieved. Can get to. The remaining effects of the third embodiment are similar to those of the aforementioned first and second embodiments.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the oil pump unit in the first embodiment, the modified example of the first embodiment, and the second embodiment, the rotor insertion shaft portion 92 of the crankshaft 90 (190, 290) is inserted into the shaft insertion hole 22 of the inner rotor 20. In this example, the oil pump 100 (105, 200) is driven, but the present invention is not limited to this. For example, the drive force of the crankshaft 90 is taken out via a belt / pulley mechanism, and the oil pump is driven by inserting (fixing) the drive shaft portion attached to the pulley shaft center into the shaft insertion hole 22 of the inner rotor 20. The present invention can also be applied to an oil pump unit configured as described above.

  Further, in the first embodiment and the modification thereof, the step formed by the inclined surface extending linearly with a certain inclination angle with respect to the X axis from the rotor insertion shaft portion 92 toward the crank journal 91 (191). Although the example which provided the surface 94a (194a) in the circumferential wall surface part 94 (194) was shown, this invention is not limited to this. For example, the step surface of the circumferential wall surface portion may be configured such that the inclination angle gradually increases from the rotor insertion shaft portion 92 toward the outermost peripheral portion. Further, for example, as in the second embodiment, the crankshaft 90 is provided with a circumferential wall portion having a step surface extending perpendicularly outward from the outer circumferential surface 92a of the rotor insertion shaft portion 92 in the radial direction. Also good.

  In the first embodiment, the modified example of the first embodiment, and the second embodiment, the groove portion 95 (195) is provided on the outer peripheral surface 92a of the rotor insertion shaft portion 92 of the crankshaft 90 (190, 290), and the third embodiment In the embodiment, an example in which the groove portion 305 is provided on the outer peripheral surface 302a of the trunk portion 302 in the sprocket 301 has been described, but the present invention is not limited thereto. That is, such groove portions 95 (195, 305) may not be provided on the rotor insertion shaft portion 92 of the crankshaft 90 and the outer peripheral surface 302a of the trunk portion 302.

  Moreover, in the said 1st Embodiment, the modification of 1st Embodiment, and 2nd Embodiment, it extends linearly along an X-axis in the outer peripheral surface 92a of the rotor insertion shaft part 92 in the crankshaft 90 (190, 290). In the third embodiment, the groove portion 95 (195) is provided, and the groove portion 395 linearly extending along the X axis is provided on the outer peripheral surface 302a of the trunk portion 302 in the sprocket 301. Not limited to. For example, while turning around the X axis at a predetermined ratio, the origin portion of the circumferential wall surface portion 94 passes through a region corresponding to the shaft insertion hole 22 from a position slightly closer to the oil seal 50 than the side end surface on the X2 side of the inner rotor 20 ( You may comprise so that the groove part which extends continuously to the X1 side edge part of the rotor insertion shaft part 92 may be provided.

  Moreover, although the said 1st Embodiment, the modification of 1st Embodiment, 2nd Embodiment, and 3rd Embodiment showed about the example which comprised the casing part 10 and the pump cover 40 (240) using the aluminum alloy. The present invention is not limited to this. That is, at least one of the casing part 10 and the pump cover 40 (240) may be made of resin. The resin is easier to deform than the metal, but the air seal of the gap caused by the deformation can be effectively performed by the oil 1 supplied to the mating surface 42 (242).

  Moreover, in the said 3rd Embodiment, although the example which provided the circumferential wall surface part 304 in the trunk | drum 302 using the sprocket 301 was shown, this invention is not limited to this. For example, a collar member or the like that includes only the body portion 302 and whose outer diameter can be adjusted may be attached to the crank journal 391, and a circumferential wall surface portion or a collar portion may be provided on the collar member.

  In the first embodiment, the modified example of the first embodiment, the second embodiment, and the third embodiment, the oil pump 100 (105, 200, 300) that supplies oil (lubricating oil) 1 to the engine 80 is used. Although an example to which the present invention is applied has been shown, the present invention is not limited to this. For example, the present invention may be applied to an oil pump for supplying AT fluid (AT oil) to an automatic transmission (AT) that automatically switches the gear ratio according to the rotational speed of the internal combustion engine. Further, unlike the AT (multi-stage transmission) that changes gears by changing the gear combination, the lubricating oil is supplied to the sliding portion in the continuously variable transmission (CVT) capable of changing the gear ratio continuously and continuously. The present invention may be applied to an oil pump for this purpose. Further, the present invention may be applied to an oil pump for supplying power steering oil to a power steering device that drives a steering (steering device) in a vehicle.

  In the first embodiment, the modification of the first embodiment, the second embodiment, and the third embodiment, the oil pump 100 (105, 200, 300) is mounted on a vehicle such as an automobile equipped with the engine 80. Although an example has been shown, the present invention is not limited to this. For example, you may apply this invention with respect to the oil pump mounted in equipment other than the vehicle provided with the internal combustion engine (engine). Moreover, as an internal combustion engine, a gasoline engine, a diesel engine, a gas engine, etc. are applicable.

1 Oil 10 Casing (pump housing)
11a Suction port 12a Discharge port 15 Opening 20 Inner rotor (oil pump rotor)
30 Outer rotor (oil pump rotor)
40, 240 Pump cover (cover)
41, 241 Shaft insertion hole (drive shaft insertion hole)
42, 242 mating surface 43, 243 surface (the surface of the cover opposite to the mating surface)
80 Engine 85 Crank chamber 90, 190, 290, 390 Crankshaft (drive shaft)
91 Crank journal (large diameter part)
92 Rotor insertion shaft (part other than large diameter part)
92a Outer peripheral surface 94, 194, 304 Peripheral wall surface portion 94a, 194a, 304a Stepped surface 94b, 194b, 294b, 304b Outermost peripheral portion 95, 195, 305 Groove portion 241a Small diameter portion 241b Large diameter portion 241c Recessed portion 291, 391 Crank journal 294 Spear-shaped part 294a Side surface 100, 105, 200, 300 Oil pump 301 Sprocket (drive shaft part)
302 trunk 302a outer peripheral part (part other than large diameter part)
302b Outer peripheral part (large diameter part)

Claims (4)

A drive shaft,
An oil pump rotor that is rotationally driven by the drive shaft;
A pump housing in which the oil pump rotor is housed;
Including a drive shaft insertion hole into which the drive shaft is inserted, and a cover for closing the opening of the pump housing,
The drive shaft portion includes a circumferential wall surface portion that protrudes circumferentially from the outer peripheral surface of the drive shaft portion,
The outermost peripheral portion of the circumferential wall surface portion is located between the mating surface of the pump housing and the cover and the surface of the cover opposite to the mating surface in the drive shaft portion insertion hole. is configured to,
The drive shaft portion insertion hole of the cover is an oil pump unit having an inner diameter on the oil pump rotor side that is larger than an inner diameter on the side opposite to the oil pump rotor . The drive shaft portion includes a large-diameter portion provided so as to extend outward from the vicinity of the drive shaft portion insertion hole of the cover,
2. The oil pump unit according to claim 1, wherein the circumferential wall surface portion is configured by a step surface located at a boundary between the large diameter portion and a portion other than the large diameter portion. The drive shaft portion includes a hook-like portion provided in the vicinity of the drive shaft portion insertion hole of the cover,
3. The oil pump unit according to claim 1, wherein the circumferential wall surface portion is configured by a side surface of the flange-shaped portion on the oil pump rotor side. The drive shaft portion further includes a groove portion provided on an outer peripheral surface of the drive shaft portion so as to extend from the oil pump rotor side toward the circumferential wall surface portion, and guiding oil to the circumferential wall surface portion. The oil pump unit according to any one of 1 to 3 .

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