JP2017155722A - Oil pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil pump capable of preventing foreign matter flowing into a control groove from intruding between an outer peripheral surface of an outer rotor and a peripheral surface of a casing member.SOLUTION: A trochoid type oil pump includes a casing member storing an inner rotor and an outer rotor 60. An inner peripheral surface of an adjustment ring 70 constituting the casing member faces an outer peripheral surface 62 of the outer rotor 60, and on the inner peripheral surface of the adjustment ring 70, a control groove 90B is provided. A portion reaching a first end E1 in an axis direction X on a downstream side wall surface 911 of the control groove 90B is inclined so that as the portion is closest to the first end E1, it is positioned on a downstream side in a regulated rotation direction Y.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a trochoid oil pump.

  The trochoidal oil pump described in Patent Document 1 includes an inner rotor that rotates integrally with an input shaft, an outer rotor that is disposed on the outer peripheral side of the inner rotor, and a casing member that accommodates each rotor. The casing member is provided with a suction port and a discharge port. As each rotor rotates, the oil sucked from the suction port is pressurized and discharged from the discharge port.

  The casing member has an annular peripheral surface facing the outer peripheral surface of the outer rotor, and a control groove is provided on the peripheral surface. When the extending direction of the input shaft is the axial direction, the control groove extends in the axial direction. Moreover, in the oil pump described in Patent Document 1, the control groove communicates with the discharge port. Therefore, when the oil pump is operating and oil is discharged from the discharge port, the internal pressure of the control groove becomes relatively high, and therefore the outer rotor can be biased in one direction by the internal pressure of the control groove. . As a result, the fluctuation of the rotation center of the outer rotor can be suppressed, and the stability of the oil discharge amount from the discharge port can be enhanced.

  Some oil pumps are provided with a control groove on the peripheral surface of the casing member in communication with the suction port. In such an oil pump, the control groove is filled with oil from the suction port. Therefore, oil flows from the control groove between the outer peripheral surface of the outer rotor and the peripheral surface of the casing member so that the oil functions as lubricating oil between the outer peripheral surface of the outer rotor and the peripheral surface of the casing member. Become. Thereby, the rotational load of the outer rotor is reduced, and the rotational stability of each rotor can be improved.

Japanese Patent Laid-Open No. 2-191858

  By the way, minute foreign matter may flow into the oil pump from the suction port together with oil, and the foreign matter may flow into the control groove. Then, the foreign matter moves to the downstream side in the rotation direction of the outer rotor in the control groove, and then enters between the outer peripheral surface of the outer rotor located on the downstream side in the rotation direction from the control groove and the peripheral surface of the casing member. May end up. In this case, the outer peripheral surface of the rotating outer rotor may be damaged by foreign matter that has entered between the outer peripheral surface of the outer rotor and the peripheral surface of the casing member.

  The objective of this invention is providing the oil pump which can suppress that the foreign material which flowed in in the control groove | channel enters between the outer peripheral surface of an outer rotor, and the surrounding surface of a casing member.

  An oil pump for solving the above problems includes an inner rotor that rotates integrally with an input shaft, an outer rotor that is disposed on the outer peripheral side of the inner rotor, and an annular peripheral surface that faces the outer peripheral surface of the outer rotor, and an input And a casing member in which a control groove extending in the axial direction, which is an extending direction of the shaft, is provided on the peripheral surface of the trochoid pump. The casing member of the oil pump is provided with a suction port for sucking oil into the casing member and a discharge port for discharging oil from the casing member to the outside. The oil sucked from the suction port is pressurized and discharged from the discharge port. In this trochoid oil pump, when the rotation direction of the outer rotor is the specified rotation direction and the wall located downstream of the specified rotation direction is the downstream wall surface of the control groove, the axial direction of the downstream wall surface The portion that reaches one end is inclined so as to be located on the downstream side in the prescribed rotational direction as it is closer to the one end.

  When foreign matter that has flowed into the oil pump from the suction port together with oil flows into the control groove, the foreign matter moves to the vicinity of the downstream side wall surface by rotation of the outer rotor in the control groove. According to the above configuration, the foreign matter that has moved to the vicinity of the inclined portion that reaches the one end of the downstream side wall surface in the control groove moves to one end in the axial direction in the control groove along the inclined wall surface. Discharged outside. Therefore, it becomes possible to prevent foreign matter that has flowed into the control groove from entering between the outer peripheral surface of the outer rotor and the peripheral surface of the casing member.

  An oil pump is known in which a discharge side control groove communicating with a discharge port is provided as a control groove on the peripheral surface of the casing member. In such an oil pump, the casing member may have a wall portion adjacent to each rotor in the axial direction, and a discharge port may be provided on the wall portion. In this case, in the casing member, the oil pressurized by the rotation of each rotor flows toward the wall portion where the discharge port is provided. Therefore, in such an oil pump, one end in the axial direction on the downstream side wall surface of the discharge side control groove is an end on the side closer to the wall portion of both ends in the axial direction on the downstream side wall surface, It is preferable to incline the portion that reaches one end in the axial direction on the downstream side wall surface of the discharge side control groove so as to be positioned on the downstream side in the specified rotational direction as it is closer to the wall portion. According to this configuration, the foreign matter that has flowed into the discharge-side control groove moves to the vicinity of the downstream side wall surface within the discharge-side control groove by the rotation of the outer rotor. Then, the foreign matter that has moved to the vicinity of the inclined portion that reaches one end of the downstream side wall surface moves along the inclined wall surface to the end closer to the wall portion in the discharge side control groove, and the discharge side control. It is discharged from the groove to the wall side. Thereafter, the foreign matter is discharged together with the oil from the discharge port provided on the wall portion to the outside of the casing member, that is, outside the oil pump. Therefore, even if foreign matter flows into the discharge-side control groove, the foreign matter can be discharged out of the casing member, so that foreign matter can be prevented from entering between the outer peripheral surface of the outer rotor and the peripheral surface of the casing member. become able to.

  Further, an oil pump is known in which a suction side control groove communicating with a suction port is provided as a control groove on the peripheral surface of the casing member. In such an oil pump, the portion reaching the one end in the axial direction on the downstream side wall surface of the suction side control groove is inclined so that the portion closer to the one end is located downstream in the prescribed rotational direction. Is preferred. According to this configuration, the foreign matter that has flowed into the suction side control groove moves to the vicinity of the downstream side wall surface in the suction side control groove by the rotation of the outer rotor. The foreign matter that has moved to the vicinity of the inclined portion that reaches one end of the downstream side wall surface moves to the axial end in the suction side control groove along the inclined wall surface, and is then discharged out of the suction side control groove. Is done. In addition, since the foreign matter discharged | emitted out of the suction side control groove in this way still remains in the casing member, the foreign matter may flow into the suction side control groove again. However, even in this case, the foreign matter can be moved along the inclined wall surface of the downstream side wall surface and discharged again out of the suction side control groove. Therefore, even if foreign matter flows into the suction side control groove, foreign matter can be prevented from entering between the outer peripheral surface of the outer rotor and the peripheral surface of the casing member.

  Here, if a wall surface perpendicular to the specified rotational direction is present in part on the downstream side wall surface of the control groove extending in the axial direction, the foreign substance is removed from the downstream side wall surface on the wall surface orthogonal to the specified rotational direction. Since it cannot guide to the edge of this, it may enter between the outer peripheral surface of an outer rotor and the said surrounding surface of a casing member. Therefore, it is preferable to incline the downstream side wall surface from the other end to the one end in the axial direction so as to be positioned on the downstream side in the specified rotation direction as it is closer to the one end. According to this configuration, no wall surface perpendicular to the prescribed rotational direction exists on the downstream side wall surface. Thereby, the foreign material which flowed into the control groove can be guided to the end of the control groove by the downstream side wall surface, and the foreign material can be discharged out of the control groove. Accordingly, it is possible to enhance the effect of suppressing foreign matter from entering between the outer peripheral surface of the outer rotor and the peripheral surface of the casing member.

  Further, when the oil pump is applied to a pump that can change the amount of oil discharged from the discharge port, the casing member is fixed to the housing provided with the suction port and the discharge port, A cover member that partitions the housing space together with the housing, and a ring-shaped variable member that is disposed in the housing space so as to be displaceable and surrounds the outer rotor may be used. In this case, the amount of oil discharged from the discharge port can be changed by displacing the variable member in the accommodating space in accordance with the supply and discharge of oil in the control oil chamber partitioned and formed in the accommodating space by the variable member. . And in such an oil pump, it is preferable that the inner peripheral surface of a variable member is made into the said surrounding surface of a casing member. According to this configuration, the control groove is provided on the inner peripheral surface of the variable member. Even if foreign matter flows into the control groove, the foreign matter that has moved to the vicinity of the inclined wall surface reaching one end of the downstream side wall surface in the control groove is moved to the end of the control groove along the inclined wall surface. By moving it, it can be discharged out of the control groove. Therefore, even in an oil pump that can vary the amount of oil discharged in this way, foreign matter that has flowed into the control groove is prevented from entering between the outer peripheral surface of the outer rotor and the inner peripheral surface of the variable member. Will be able to.

It is sectional drawing which shows one Embodiment of an oil pump, Comprising: The figure which shows the position of the adjustment ring when the discharge amount of oil is the maximum. It is sectional drawing of the oil pump of the embodiment, Comprising: The figure which shows the position of the adjustment ring when the discharge amount of oil is small. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 1. FIG. 4 is a sectional view taken along line 4-4 in FIG. The perspective view which shows a part of adjustment ring of the oil pump of the embodiment. FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. Sectional drawing which shows typically the shape of the downstream side wall surface of a control groove in the oil pump of another embodiment. Sectional drawing which shows typically the shape of the downstream side wall surface of a control groove in the oil pump of another embodiment. Sectional drawing which shows typically the shape of the downstream side wall surface of the suction side control groove in the oil pump of another embodiment.

Hereinafter, an embodiment embodying a trochoid oil pump will be described with reference to FIGS.
The oil pump 10 of this embodiment shown in FIGS. 1 and 2 is a variable displacement pump that is attached to an internal combustion engine and operates based on rotation of a crankshaft of the internal combustion engine. As shown in FIGS. 1 and 2, the oil pump 10 is disposed on the outer peripheral side of the input shaft 11 that rotates in synchronization with the crankshaft, the inner rotor 50 that rotates integrally with the input shaft 11, and the inner rotor 50. The outer rotor 60 and a casing member CS in which the rotors 50 and 60 are accommodated are provided. The casing member CS is provided with a suction port 12 for sucking oil therein and a discharge port 13 for discharging the oil inside the casing member CS. The suction port 12 communicates with an oil passage that leads to an oil pan through an oil strainer. Further, the discharge port 13 communicates with a discharge oil passage 13a that communicates with the main gallery of the oil supply system.

  A plurality of outer teeth 51 are provided on the outer periphery of the inner rotor 50, and a plurality of inner teeth 61 that mesh with the outer teeth 51 of the inner rotor 50 are provided on the inner periphery of the outer rotor 60. The number of inner teeth 61 is one more than the number of outer teeth 51. The outer rotor 60 is rotatably held by the casing member CS.

  The rotation center of the outer rotor 60 is eccentric with respect to the rotation center of the inner rotor 50. The outer teeth 51 of the inner rotor 50 and the inner teeth 61 of the outer rotor 60 are in a state in which a part thereof (the right side portion in FIG. 1) is engaged with each other. A working chamber 41 filled with oil is formed between the outer periphery of the inner rotor 50 and the inner periphery of the outer rotor 60.

  In the working chamber 41, from the position where the outer teeth 51 of the inner rotor 50 and the inner teeth 61 of the outer rotor 60 mesh with each other, in the rotational direction of the input shaft 11 (hereinafter also referred to as “specified rotational direction Y”) indicated by an arrow in FIG. In the portion up to the predetermined position, the clearance between the outer teeth 51 of the inner rotor 50 and the inner teeth 61 of the outer rotor 60 gradually increases as the rotors 50 and 60 rotate. The portion where the gap between the outer teeth 51 of the inner rotor 50 and the inner teeth 61 of the outer rotor 60 gradually increases in this way communicates with the suction port 12. On the other hand, in the working chamber 41, a portion where the gap between the outer teeth 51 of the inner rotor 50 and the inner teeth 61 of the outer rotor 60 gradually decreases as the rotors 50 and 60 rotate is in communication with the discharge port 13.

  When the oil pump 10 operates, the input shaft 11 rotates, so that the rotors 50 and 60 rotate while meshing with each other. Then, the oil stored in the oil pan is sucked into the working chamber 41 from the suction port 12 through the oil strainer, and discharged from the discharge port 13 to the discharge oil passage 13a. The oil discharged to the discharge oil passage 13a in this way flows through the discharge oil passage 13a, is supplied to the main gallery of the oil supply system, and is supplied from the main gallery to the crank journal and the cam journal.

  As shown in FIGS. 1 and 3, the casing member CS includes a housing 20 in which the suction port 12 and the discharge port 13 are provided, and a cover member 30 that is assembled to the housing 20 and partitions the accommodation space 40 together with the housing 20. And an adjustment ring 70 which is an example of a variable member arranged in a displaceable state in the accommodation space 40.

  When the extending direction of the input shaft 11 is the axial direction X, the housing 20 is adjusted in the radial direction around the input shaft 11 and the bottom wall 21 as a wall portion adjacent to the rotors 50 and 60 in the axial direction X. It has an annular side wall 22 located outside the ring 70. A suction port 12 and a discharge port 13 are provided on the bottom wall 21.

  As shown in FIG. 3, the cover member 30 is fixed to the tip (upper side in FIG. 3) of the side wall 22 of the housing 20. A suction side recess 31 that communicates with the inside of the housing 20 is provided in a portion of the cover member 30 that is located on the opposite side of the suction port 12 across the rotors 50 and 60 in the axial direction X. As shown by arrows in FIG. 3, a part of the oil sucked into the accommodation space 40 through the suction port 12 flows directly into the working chamber 41 between the rotors 50 and 60 from the suction port 12. The remaining oil flows into the suction side recess 31 from the suction port 12 and flows into the working chamber 41 from the suction side recess 31. That is, in the present embodiment, the oil sucked from the suction port 12 is supplied to the working chamber 41 from both sides in the axial direction X.

  Further, as shown in FIG. 4, a discharge side recess communicating with the inside of the housing 20 is provided in a portion of the cover member 30 located on the opposite side of the discharge port 13 across the rotors 50 and 60 in the axial direction X. 32 is provided. As indicated by arrows in FIG. 4, the oil pressurized by the rotors 50 and 60 is not only from the working chamber 41 to the discharge port 13 side in the axial direction X but also from the opposite side of the discharge port 13 in the axial direction X. That is, it flows out into the discharge side recess 32. The oil in the discharge side recess 32 flows into the discharge port 13 through a gap between the outer rotor 60 and the adjustment ring 70 (particularly, discharge side control grooves 90A and 90B described later). Then, oil is discharged from the discharge port 13 to the outside of the housing 20.

  As shown in FIGS. 1 and 2, the adjustment ring 70 includes a ring-shaped main body 71 that holds the outer rotor 60, and a protrusion 72 that protrudes from the outer periphery of the main body 71 in the radial direction of the rotors 50 and 60. doing. The inner peripheral surface 713 of the main body 71 faces the outer peripheral surface 62 of the outer rotor 60. That is, in the present embodiment, the inner peripheral surface 713 of the main body 71 corresponds to the “peripheral surface of the casing member CS” that faces the outer peripheral surface 62 of the outer rotor 60.

  The main body 71 of the adjustment ring 70 is provided with elongated holes 711 and 712 extending in the specified direction. Guide pins 81 and 82 fixed to the bottom wall 21 of the housing 20 are inserted through the long holes 711 and 712. Thereby, the adjustment ring 70 can be displaced in the extending direction of the long holes 711 and 712 in a state where displacement in a direction different from the extending direction of the long holes 711 and 712 is regulated by the guide pins 81 and 82. Yes.

  A first seal member 83 is provided at the tip of the protrusion 72 of the adjustment ring 70, and a second seal member 84 is provided in the main body 71. The seal members 83 and 84 are in contact with the side wall 22 of the housing 20, and the space between the side wall 22 and the outer periphery of the adjustment ring 70 is sealed, so that the control oil chamber 42 is defined in the accommodation space 40. . The adjustment ring 70 is displaced in the extending direction of the long holes 711 and 712 in a state where the sliding contact between the seal members 83 and 84 and the side wall 22 of the housing 20 is maintained.

  The control oil chamber 42 is provided with an opening 14 communicating with the control oil passage 111, and oil can be supplied to the control oil chamber 42 from an oil control valve 100 described later through the control oil passage 111 and the opening 14. It has become. In addition, the accommodation space 40 is provided with a spring 15 that applies an urging force to the projecting portion 72 in a direction to reduce the volume of the control oil chamber 42. The spring 15 is disposed on the opposite side of the control oil chamber 42 with the protrusion 72 interposed therebetween. When the internal pressure of the control oil chamber 42 increases due to the supply of oil to the control oil chamber 42, the adjustment ring 70 is displaced in the direction of increasing the volume of the control oil chamber 42 against the urging force from the spring 15. That is, the adjustment ring 70 is displaced while rotating in the direction (counterclockwise direction in FIG. 1) from the state shown in FIG. 1 toward the state shown in FIG. On the other hand, when the oil is discharged from the control oil chamber 42 by the operation of the oil control valve 100, the internal pressure of the control oil chamber 42 is reduced, and the volume of the control oil chamber 42 is reduced by the urging force from the spring 15. The adjustment ring 70 is displaced in the direction. That is, the adjustment ring 70 is displaced while rotating in the direction from the state shown in FIG. 2 toward the state shown in FIG. 1 (clockwise direction in FIG. 2). That is, the position of the adjustment ring 70 is determined by the internal pressure of the control oil chamber 42 and the urging force from the spring 15. As the position of the adjustment ring 70 changes, the relative positions of the meshed portions of the teeth 51 and 61 of the inner rotor 50 and the outer rotor 60 with respect to the openings of the suction port 12 and the discharge port 13 change. For this reason, the amount of oil discharged from the discharge port 13 per rotation of the input shaft 11 is changed through a change in the position of the adjustment ring 70 by adjusting the internal pressure of the control oil chamber 42.

  Specifically, as shown in FIG. 1, when the internal pressure of the control oil chamber 42 increases from a state where the oil discharge amount is at the maximum, the adjustment ring 70 is attached from the spring 15 as the internal pressure increases. It is displaced while rotating counterclockwise in FIG. 1 against the force. As a result, in the portion where the gap between the external teeth 51 and the internal teeth 61 gradually increases with the rotation of the rotors 50 and 60, the range overlapping the suction port 12 becomes small, and the external teeth 51 and the internal teeth A part of the portion where the gap with 61 gradually decreases overlaps with the suction port 12. As a result, the amount of oil discharged from the discharge port 13 is reduced. On the other hand, when the internal pressure of the control oil chamber 42 decreases, the adjustment ring 70 is displaced while being rotated clockwise in FIG. Increases oil discharge.

  The oil control valve 100 can switch the communication state of a plurality of oil passages by switching the position of the spool with an electromagnetic solenoid. That is, the oil control valve 100 discharges oil from the control port 101 to which the control oil passage 111 is connected, the supply port 102 to which the supply oil passage 112 branched from the discharge oil passage 13a of the oil pump 10 is connected, and oil. And a discharge port 103 to which the discharge oil passage 113 is connected. Then, by controlling the current flowing through the electromagnetic solenoid and changing the position of the spool, the position of the spool discharges the oil returned to the control port 101 from the discharge port 103 (FIG. 1), and the supply It switches between the supply position (FIG. 2) which sends the oil supplied to the port 102 from the control port 101 to the control oil path 111.

Next, a configuration for improving the rotational stability of the rotors 50 and 60 will be described.
As shown in FIGS. 1 and 2, a plurality (three in this embodiment) of control grooves 90 </ b> A, 90 </ b> B, and 90 </ b> C are arranged along the circumferential direction on the inner peripheral surface 713 of the main body 71 of the adjustment ring 70. Has been. Each of the control grooves 90 </ b> A, 90 </ b> B, 90 </ b> C extends in the axial direction X and opens at both end surfaces of the adjustment ring 70 in the axial direction X.

  Of the three control grooves 90A, 90B, 90C, two control grooves are discharge side control grooves 90A, 90B communicating with the discharge port 13. Of the discharge side control grooves 90A and 90B, one discharge side control groove 90A is disposed at substantially the same position as the second seal member 84 in the circumferential direction, and the other discharge side control groove 90B has a specified rotation. In the direction Y, it is disposed upstream of the one discharge side control groove 90 </ b> A and downstream of the protrusion 72. Since the discharge side control grooves 90A and 90B communicate with the discharge port 13, their internal pressure is relatively high. Therefore, it is possible to suppress wobbling of the rotation center of the outer rotor 60 by biasing the outer rotor 60 in one direction by the internal pressure of each of the discharge side control grooves 90A and 90B.

  On the other hand, of the three control grooves 90A, 90B, 90C, the remaining control groove is a suction side control groove 90C communicating with the suction port 12. The suction side control groove 90C is arranged on the opposite side of the discharge side control groove 90A with the input shaft 11 interposed therebetween. The suction side control groove 90 </ b> C is filled with oil from the suction port 12 in communication. Therefore, oil flows from the suction side control groove 90 </ b> C between the outer peripheral surface 62 of the outer rotor 60 and the inner peripheral surface 713 of the main body 71 of the adjustment ring 70, and the outer peripheral surface 62 of the outer rotor 60 and the inner periphery of the main body 71. The oil functions as a lubricating oil with the surface 713. Thereby, the rotational load of the outer rotor 60 is reduced, and the rotational stability of the rotors 50 and 60 is improved.

  Each of the wall surfaces 91 of the control grooves 90 </ b> A to 90 </ b> C has a downstream side wall surface 911 which is a surface located on the downstream side in the specified rotation direction Y that is the rotation direction of the outer rotor 60. 5 and 6 illustrate the configuration of the discharge-side control groove 90B among the control grooves 90A to 90C. Since the shape of the downstream side wall surface 911 of the other control grooves 90A and 90C is substantially the same as the shape of the downstream side wall surface 911 of the discharge side control groove 90B, all of the control grooves 90A to 90A to 90D are referred to. The shape of the downstream side wall surface 911 of 90C will be described, and the illustration of the shape of the downstream side wall surface 911 of the other control grooves 90A and 90C is omitted here.

  That is, of the ends in the axial direction X of the downstream side wall surface 911 of each of the control grooves 90A to 90C, the end closer to the bottom wall 21 of the housing 20 is referred to as a first end E1, and the side far from the bottom wall 21, ie, the cover The end close to the member 30 is referred to as a second end E2. In this case, as shown in FIGS. 5 and 6, the downstream side wall surface 911 extends from the second end E2 to the first end E1 in the axial direction X in the specified rotational direction Y as it is closer to the first end E1. It inclines so that it may be located in the downstream. In other words, in the present embodiment, the portion of the downstream side wall surface 911 that reaches the first end E1 in the axial direction X is inclined so as to be positioned on the downstream side in the specified rotational direction Y as it is closer to the first end E1.

Next, the action when a minute foreign matter B such as iron powder flows into the discharge side control grooves 90A and 90B will be described together with the effect.
As shown in FIG. 6, when the foreign matter B flows into the discharge side control grooves 90A and 90B, the foreign matter B moves to the vicinity of the downstream side wall surface 911 in the discharge side control grooves 90A and 90B by the rotation of the outer rotor 60. . The foreign matter B moves to the first end E1 on the side close to the bottom wall 21 of the housing 20 in the discharge side control grooves 90A and 90B along the inclined downstream side wall surface 911, and then the discharge side control grooves 90A and 90A. It is discharged out of 90B. That is, in this embodiment, the foreign matter B that has flowed into the discharge side control grooves 90A and 90B is guided to the discharge port 13 side by the downstream side wall surface 911. Therefore, the foreign matter B discharged from the discharge side control grooves 90A and 90B in this way is discharged out of the housing 20 from the discharge port 13 together with the oil.

  Here, as described with reference to FIG. 4, oil flows to the discharge port 13 side in the axial direction X in the discharge side control grooves 90 </ b> A and 90 </ b> B. Therefore, contrary to the case of the present embodiment, even if the entire downstream side wall surface is inclined so as to be positioned on the downstream side in the specified rotational direction Y as it is closer to the second end E2 in the axial direction X, the discharge side control is performed. Due to the oil flow in the grooves 90A and 90B, it is difficult to move the foreign matter B to the second end E2 in the discharge side control grooves 90A and 90B on the downstream side wall surface. As a result, the foreign matter B cannot be discharged out of the discharge-side control grooves 90A and 90B, and the period during which the foreign matter B stays in the discharge-side control grooves 90A and 90B becomes longer. The longer the period of staying in this way, the higher the possibility that foreign matter B will enter between the outer peripheral surface 62 of the outer rotor 60 and the inner peripheral surface 713 of the adjustment ring 70. On the other hand, in the present embodiment, the entire downstream side wall surface 911 is inclined so as to be positioned on the downstream side in the specified rotational direction Y as it approaches the first end E1 in the axial direction X. Foreign matter B that has flowed into 90A and 90B can be quickly discharged out of discharge side control grooves 90A and 90B.

  That is, in the present embodiment, even if the foreign matter B flows into the discharge side control grooves 90 </ b> A and 90 </ b> B, the foreign matter B can be discharged to the housing 20 through the discharge port 13. Accordingly, it is possible to prevent the foreign matter B from entering between the outer peripheral surface 62 of the outer rotor 60 and the inner peripheral surface 713 of the adjustment ring 70. That is, the outer peripheral surface 62 of the outer rotor 60 can be prevented from being damaged.

  The adjustment ring 70 provided with the discharge side control grooves 90 </ b> A and 90 </ b> B is displaced according to the internal pressure of the control oil chamber 42. However, as shown in FIGS. 1 and 2, the communication between the discharge side control grooves 90 </ b> A and 90 </ b> B and the discharge port 13 is possible regardless of the position of the adjustment ring 70 within the movable range of the adjustment ring 70. Is maintained. Therefore, regardless of the position of the adjustment ring 70, the foreign matter B that has flowed into the discharge side control grooves 90A and 90B can be discharged to the discharge port 13 by the downstream side wall surface 911.

Next, the action when the foreign matter B flows into the suction side control groove 90C will be described together with the effects.
When the foreign matter B flows into the suction side control groove 90C, the foreign matter B moves to the vicinity of the downstream side wall surface 911 in the suction side control groove 90C by the rotation of the outer rotor 60. Such foreign matter B moves along the inclined downstream side wall surface 911 to the first end E1 on the side close to the bottom wall 21 of the housing 20 in the suction side control groove 90C, and then is discharged out of the suction side control groove 90C. Is done.

  Since the foreign matter B discharged out of the suction side control groove 90C still remains in the accommodation space 40, the foreign matter B may flow into the suction side control groove 90C again. However, even in this case, the foreign matter B can be moved along the downstream side wall surface 911 of the suction side control groove 90C and discharged again out of the suction side control groove 90C. Therefore, even if the foreign matter B flows into the suction side control groove 90 </ b> C, the foreign matter B can be prevented from entering between the outer peripheral surface 62 of the outer rotor 60 and the inner peripheral surface 713 of the adjustment ring 70.

The above embodiment may be changed to another embodiment as described below.
In the above embodiment, the downstream side wall surface 911 of each of the control grooves 90A to 90C is inclined with a constant gradient from the second end E2 to the first end E1 in the axial direction X. However, the present invention is not limited thereto, and the slope of the downstream side wall surface 911 may be gradually changed from the second end E2 in the axial direction X toward the first end E1. For example, as shown in FIG. 7, the slope of the downstream side wall surface 911 may be gradually increased from the second end E2 in the axial direction X toward the first end E1. The “inclination gradient” referred to here is a gradient based on a plane VS which is a plane indicated by a two-dot chain line in FIG. Even if it is such a structure, the effect similar to the said embodiment can be acquired.

  In the above embodiment, the downstream side wall surface 911 of each of the control grooves 90A to 90C extends from the second end E2 to the first end E1 in the axial direction X in the specified rotational direction Y as it is closer to the first end E1. It inclines so that it may be located in the downstream. However, the present invention is not limited to this, and the portion of the downstream side wall surface 911 that reaches the first end E1 in the axial direction X is inclined so as to be positioned on the downstream side in the specified rotational direction Y as it is closer to the first end E1. If there is, for example, as shown in FIG. 8, only a part of the downstream side wall surface 911 may be inclined. In this case, the foreign matter B that has moved to the vicinity of the inclined wall surface 911A in the downstream side wall surface 911 in the control grooves 90A to 90C is moved in the axial direction X of the control grooves 90A to 90C along the wall surface 911A. It moves to the first end E1 and is discharged out of the control grooves 90A to 90C. Therefore, the foreign matter B that has flowed into the control grooves 90 </ b> A to 90 </ b> C can be prevented from entering the outer peripheral surface 62 of the outer rotor 60 and the inner peripheral surface 713 of the adjustment ring 70.

  The foreign matter B that has flowed into the suction side control groove 90C may be discharged to the suction port 12 side in the axial direction X, or discharged to the opposite side of the suction port 12 in the axial direction X, that is, the suction side recess 31 side. Also good. Therefore, the downstream side wall surface 911 of the suction-side control groove 90C is positioned on the downstream side in the specified rotational direction Y as it approaches the second end E2 over the entire length from the first end E1 to the second end E2 in the axial direction X. It may be inclined like this. Even with such a configuration, the foreign matter B that has flowed into the suction side control groove 90C can be discharged to the suction side concave portion 31 side by the downstream side wall surface 911. Therefore, the outer peripheral surface 62 of the outer rotor 60 and the inner peripheral surface of the adjustment ring 70 It is possible to prevent foreign matter B from entering between 713 and 713.

  Further, as shown in FIG. 9, the downstream side wall surface 911 of the suction side control groove 90C is divided into a first downstream side wall surface 911B on the bottom wall 21 side of the housing 20 and a second downstream side wall surface 911C on the cover member 30 side. It is good also as a structure which has. In this case, the first downstream side wall surface 911B is inclined so as to be positioned on the downstream side in the prescribed rotational direction Y as it is closer to the first end E1. Further, the second downstream side wall surface 911C is inclined so as to be located on the downstream side in the prescribed rotational direction Y as it is closer to the second end E2. Even in such a configuration, the foreign matter B that has flowed into the suction-side control groove 90C can be discharged out of the suction-side control groove 90C by the downstream side wall surface 911. Therefore, the outer peripheral surface 62 of the outer rotor 60 and the inner periphery of the adjustment ring 70 The foreign matter B can be prevented from entering between the surface 713 and the surface 713.

  When the oil flow in the discharge side control grooves 90A and 90B is slow, the foreign matter B that has flowed into the discharge side control grooves 90A and 90B is moved against the oil flow to the discharge side recess 32 side. There is a possibility of discharging. Therefore, in the oil pump in which the oil flow in the discharge side control grooves 90A and 90B is slow as described above, the downstream side wall surface 911 of the discharge side control grooves 90A and 90B is moved from the first end E1 in the axial direction X. You may make it incline so that it may be located in the downstream of the regular rotation direction Y, so that it may approach 2nd end E2 over the whole to 2nd end E2. Further, of the downstream side wall surfaces 911 of the discharge side control grooves 90A and 90B, the wall surface including the first end E1 in the axial direction X is inclined so as to be positioned on the downstream side in the specified rotational direction Y as it is closer to the first end E1. In addition, the wall surface including the second end E2 in the axial direction X may be inclined so as to be positioned on the downstream side in the specified rotational direction Y as it is closer to the second end E2.

  The oil pump may be embodied as a fixed capacity pump that cannot change the oil discharge amount. The casing member of such an oil pump is comprised from the housing and the cover member, and does not have an adjustment ring. Therefore, the outer rotor 60 is held by the housing, and since the side wall of the housing has an annular peripheral surface that faces the outer peripheral surface 62 of the outer rotor 60, a control groove is provided on the peripheral surface. Become. Then, by tilting a portion of the downstream side wall surface of the control groove that reaches one end in the axial direction X so as to be closer to the downstream side in the specified rotational direction Y, the outer circumferential surface 62 of the outer rotor 60 The foreign matter B can be prevented from entering between the outer peripheral surface 62 and the peripheral surface of the side wall of the housing.

  DESCRIPTION OF SYMBOLS 10 ... Oil pump, 11 ... Input shaft, 12 ... Intake port, 13 ... Discharge port, 20 ... Housing, 21 ... Bottom wall, 30 ... Cover member, 40 ... Storage space, 42 ... Control oil chamber, 50 ... Inner rotor, 60 DESCRIPTION OF SYMBOLS ... Outer rotor, 62 ... Outer peripheral surface, 70 ... Adjustment ring, 713 ... Inner peripheral surface, CS ... Casing member, 90A, 90B ... Discharge side control groove, 90C ... Suction side control groove, 91 ... Wall surface, 911 ... Downstream side wall surface.

Claims (5)

An axial direction that has an inner rotor that rotates integrally with the input shaft, an outer rotor that is disposed on the outer peripheral side of the inner rotor, and an annular peripheral surface that faces the outer peripheral surface of the outer rotor, and is an extending direction of the input shaft A casing member provided on the peripheral surface with a control groove extending to
The casing member is provided with a suction port for sucking oil into the casing member, and a discharge port for discharging oil from the casing member to the outside.
In the trochoid oil pump that pressurizes oil sucked from the suction port and discharges it from the discharge port by rotating each rotor,
When the rotation direction of the outer rotor is a specified rotation direction, and the wall located on the downstream side of the specified rotation direction among the wall surfaces of the control groove is a downstream wall surface, it reaches one end of the downstream wall surface in the axial direction. The oil pump is characterized in that the portion of the oil pump is inclined so as to be positioned on the downstream side in the prescribed rotational direction as it is closer to the one end. On the peripheral surface of the casing member, a discharge side control groove communicating with the discharge port is provided as the control groove,
The casing member has a wall portion adjacent to the rotor in the axial direction, and the discharge port is provided in the wall portion,
One end in the axial direction of the downstream side wall surface of the discharge side control groove is an end on the side closer to the wall portion among both ends in the axial direction of the downstream side wall surface,
The oil pump according to claim 1, wherein a portion of the downstream side wall surface reaching one end in the axial direction is inclined so as to be positioned on the downstream side in the prescribed rotational direction as the wall portion is closer. A suction side control groove communicating with the suction port is provided as the control groove on the peripheral surface of the casing member.
The portion of the downstream side wall surface of the suction side control groove that reaches one end in the axial direction is inclined so as to be positioned on the downstream side in the prescribed rotational direction as it is closer to the one end. Oil pump as described in The said downstream side wall surface is inclined so that it may be located in the downstream of the said regular rotation direction, so that it is near this one end over the whole from the other end of the said axial direction to one end. The oil pump as described in any one of Claims. The casing member is disposed in a state in which the housing is provided with the suction port and the discharge port, a cover member that is fixed to the housing and defines a housing space together with the housing, and is displaceable in the housing space. And a ring-shaped variable member surrounding the outer rotor,
In the accommodating space, a control oil chamber is defined by the variable member,
When the variable member is displaced in the accommodation space according to the supply / discharge of oil in the control oil chamber, the amount of oil discharged from the discharge port is changed,
The oil pump according to any one of claims 1 to 4, wherein an inner peripheral surface of the variable member is the peripheral surface provided with the control groove.

Images