JP4193767B2 - Vane pump - Google Patents

Description

  The present invention relates to a vane pump in which a rotor having a plurality of vanes is rotated in a cam ring, and the volume of a working chamber between adjacent vanes is changed with the rotation to perform a pumping action.

  In a vane pump known as one type of pump, a rotor is generally provided in a cam ring. The rotor is provided with a plurality of vane grooves that open on the outer peripheral surface thereof and extend toward the center of the rotor, and the vanes are slidably accommodated in the respective vane grooves. In this vane pump, the volume of the working chamber between adjacent vanes changes as the rotor rotates, and the suction, pressurization, and discharge of liquid are performed by the change.

  In order to perform such a pumping action, it is important that each vane is urged radially outward and always contacts the cam surface on the inner periphery of the cam ring. In order to energize the vanes, a back pressure chamber is provided at the bottom of each vane groove, and high-pressure fluid discharged from the working chamber is introduced into the back pressure chamber.

Such a vane pump is provided with a side plate that is provided to face each side surface of the rotor and the vane in the axial direction of the rotor and that constitutes a part of the side wall of the working chamber. In addition, as a prior art document concerning this invention, there exists a vane pump etc. which are described in patent document 1, for example. In this vane pump, a cam ring is accommodated in a housing, and members functioning as the side plates such as a side plate and a cover are provided on each side surface of the cam ring.
JP-A-9-242679

  By the way, each side plate has a groove that opens toward each side surface of the vane and discharges fluid from the working chamber, and a groove that opens toward each side surface of the vane. A suction port for sucking fluid, a side surface of the rotor and the vane, and a back pressure introduction groove for guiding the fluid discharged from the working chamber, which is a groove opened toward the back pressure chamber, are formed. .

  Further, in order to enable rotation of the rotor and vanes within the cam ring, the thickness of the rotor and vanes in the axial direction of the rotor is set to be approximately the same as or slightly smaller than the distance between the side plates. That is, there is a certain amount of clearance (about 0 μm to several tens of μm) between one side surface of the rotor and the vane and the side plate facing this, and between the other side surface of the rotor and the vane and the side plate facing this. Each is provided. Since fluid flows into each clearance through the discharge port, the suction port, or the back pressure introduction groove, the pressure of the fluid acts on each side of the rotor and the vane. Thrust force acting in the direction is applied.

  Here, the fluid flows in the clearance between the one side surface of the rotor and the vane and the side plate facing the rotor, and the clearance between the other side surface of the rotor and the vane and the side plate facing the same are different. In this case, the fluid pressures acting on one side surface of the rotor and the vane and the other side surface of the rotor and the vane are different. Therefore, in this case, the rotor and the vane are pressed against one of the side plates, and the one side plate is worn in the sliding range of the rotor and the vane. When such stepped wear occurs, the clearance increases, so the amount of fluid leakage from the clearance also increases, and the volumetric efficiency of the pump may decrease.

  On the other hand, as shown in FIG. 9, the fixed side plate 2 provided facing one side of the rotor 17 and the vane 25 and the other side of the rotor 17 and the vane 25 are provided facing the other side of the cam ring 12. In a vane pump that includes a movable side plate 30 that slides in the axial direction of the rotor 17 and is biased toward the fixed side plate 2, the rotor 17 and the vane 25 are pressed against the fixed side plate 2. Here, since the side surface of the rotor 17 and the vane 25 slides on almost the entire surface of the movable side plate 30 facing the rotor 17 and the vane 25, stepped wear hardly occurs, and clearance compensation due to wear is also compensated. Easy. However, on the fixed side plate 2 side, stepped wear may occur in the above-described manner. Therefore, an increase in the clearance on the fixed side plate 2 side increases the amount of fluid leakage at that portion, and the volumetric efficiency of the pump. May fall. The volumetric efficiency of the pump is an efficiency defined by the following equation.

Volumetric efficiency ηv of pump = discharge amount Qp at pressure P / theoretical discharge amount Q0 × 100
("Q0-Qp" corresponds to the total leak amount inside the pump)

Incidentally, if each side plate is a movable side plate as described above, the occurrence of stepped wear on each side plate can be suppressed, but the following problems will newly arise.

  That is, the movable side plate 30 slides in the cam ring 12, but if the clearance between the outer peripheral surface of the movable side plate 30 and the inner peripheral surface of the cam ring 12 is large, the amount of leakage from that portion increases. The pump efficiency will be reduced. Therefore, it is desirable to make such clearance as small as possible. Here, the outer peripheral surface of the movable side plate 30 is a cam surface approximated to the inner peripheral shape of the cam ring 12 in order to secure the airtightness of the working chamber as much as possible. Therefore, when the outer peripheral surface of the movable side plate 30 is formed, high processing accuracy is required in the first place, but further reduction in clearance requires higher processing accuracy. Therefore, in a vane pump that uses a plurality of the movable side plates 30, an increase in cost or the like is unavoidable.

  This invention is made | formed in view of such a situation, The objective is to provide the vane pump which can suppress suitably the fall of the volumetric efficiency of a pump.

In the following, means for achieving the above object and its effects are described.
The invention according to claim 1 is provided in each of the cam ring, the rotor provided in the cam ring, and the plurality of vane grooves opened in the outer peripheral surface of the rotor, and the rotation of the rotor causes A plurality of vanes sliding on the cam surface and a plurality of working chambers divided between adjacent vanes, and the volume of each working chamber is changed by the rotation of the rotor, so that the suction passage leads into the working chamber. In a vane pump that sucks fluid and discharges the fluid in a pressurized state from a discharge passage, the vane pump is provided facing one side surface of the rotor and the vane in the axial direction of the rotor, and is provided on one side wall of the working chamber. The fixed side plate constituting the portion and the other side surface of the rotor and the vane are provided so as to be slidable in the axial direction of the rotor in the cam ring and attached to the fixed side plate. It is a movable side plate that constitutes a part of the side wall of the working chamber, as its gist in that the rotor and the vanes and a biasing mechanism for biasing the movable side plate.

  According to this configuration, the rotor and the vane are urged toward the movable side plate by the urging mechanism. Therefore, the side surfaces of the rotor and the vane slide mainly on the movable side plate side, and the sliding between the rotor and the vane and the fixed side plate is suppressed. Therefore, the occurrence of stepped wear on the fixed side plate is suppressed, and a decrease in volumetric efficiency of the pump can be suitably suppressed.

  Incidentally, although the movable side plate is worn according to the configuration, the increase in the clearance due to the wear is compensated by the movement of the movable side plate toward the fixed side plate. Therefore, a decrease in volumetric efficiency due to wear of the movable side plate is also suppressed.

  The movable side plate is biased toward the fixed side plate by using an elastic member such as a spring, or back pressure (discharged from the inside of the vane pump) on the surface of the movable plate opposite to the fixed plate side. It is possible to adopt a mode in which a fluid pressure is applied.

  According to a second aspect of the present invention, in the vane pump according to the first aspect, a back pressure chamber into which a fluid discharged from the working chamber is guided is provided at the bottom of the vane groove, and the stationary side plate is provided with the back pressure chamber. And a fixed-side discharge port that discharges the fluid from the working chamber to the discharge passage, the groove being open toward the side surface of the vane, and a surface facing the side surface of the rotor and the vane. A groove that is open toward the side surface of the fixed side, and is open toward the side surface of the rotor and the vane, and the back pressure chamber, and sucks the fluid from the suction passage into the working chamber. A fixed-side back pressure introduction groove through which fluid discharged from the working chamber is guided is formed on a surface of the movable side plate facing the side surfaces of the rotor and the vane. Side of A movable-side discharge port that discharges the fluid from the working chamber to the discharge passage, and a groove that opens toward the side surface of the vane and extends from the suction passage to the working chamber. A movable side suction port for sucking the fluid, a side surface of the rotor and the vane, and a groove opened toward the back pressure chamber, and a fluid side back pressure to which fluid discharged from the working chamber is guided The biasing mechanism is formed such that an opening area of the fixed-side discharge port is larger than an opening area of the movable-side discharge port, and an opening area of the fixed-side suction port is set to the movable-side The gist of the present invention is that it is formed larger than the opening area of the suction port, and the opening area of the fixed-side back pressure introduction groove is larger than the opening area of the movable-side back pressure introduction groove. That.

  According to this configuration, the opening area of the fixed discharge port is formed larger than the opening area of the movable discharge port, and the opening area of the fixed suction port is formed larger than the opening area of the movable suction port. The opening area of the fixed-side back pressure introduction groove is formed larger than the opening area of the movable-side back pressure introduction groove. Therefore, the pressure receiving area of the fluid pressure on one side of the rotor and vane facing the fixed side plate is larger than the pressure receiving area of the fluid pressure on the other side of the rotor and vane facing the movable side plate. Due to the difference, the rotor and the vane are biased toward the movable side plate. As described above, according to the above configuration, the rotor and the vane can be reliably urged toward the movable side plate.

  According to a third aspect of the present invention, in the vane pump according to the first aspect, a back pressure chamber into which a fluid discharged from the working chamber is guided is provided at the bottom of the vane groove. The rotor and the vane facing the fixed side plate are provided on one side surface of the vane, are opened toward the fixed side plate, and are configured by a step portion formed to communicate with the back pressure chamber. The gist.

  According to this configuration, the fluid pressure in the back pressure chamber acts on the stepped portion. Here, the stepped portion is provided on one side surface of the rotor and the vane facing the fixed side plate, and is opened toward the fixed side plate. Therefore, the fluid pressure acts on one side surface of the fixed side plate, the rotor, and the vane, and the rotor and vane are biased toward the movable side plate. Therefore, according to the above configuration, the rotor and the vane can be reliably urged toward the movable side plate.

  According to a fourth aspect of the present invention, in the vane pump according to the first aspect, the bottom portion of the vane groove is formed by a bottom surface of the vane groove and an inner end surface of the vane facing the bottom surface. A back pressure chamber is provided through which fluid discharged from the working chamber is guided, and the biasing mechanism is formed by the bottom surface and the inner end surface formed so that the back pressure chamber expands toward the fixed side plate. The gist is that it is composed.

  In this configuration, a back pressure chamber is formed which is formed by the bottom surface of the vane groove and the inner end surface of the vane facing the bottom surface and into which the fluid discharged from the working chamber is guided. Therefore, fluid pressure acts on the bottom surface of the vane groove and the inner end surface of the vane. Here, the bottom surface of the vane groove and the inner end surface of the vane are formed so that the back pressure chamber expands toward the fixed side plate. Therefore, the fluid pressure acting on the bottom surface of the vane groove and the inner end surface of the vane acts in the axial direction of the rotor toward the movable side plate. Therefore, the rotor and the vane are biased toward the movable side plate. As described above, according to the above configuration, the rotor and the vane can be reliably urged toward the movable side plate.

  According to the fifth aspect of the present invention, by adopting a configuration in which the bottom surface of the vane groove and the inner end surface of the vane are formed with inclined surfaces, the back pressure chamber is expanded toward the fixed side plate. In addition, the fluid pressure acting on the bottom surface of the vane groove and the inner end surface of the vane can be reliably applied to the movable side plate in the axial direction of the rotor.

  Further, according to the invention described in claim 6, by adopting a configuration in which the bottom surface of the vane groove and the inner end surface of the vane are formed in a step shape, the back pressure chamber toward the fixed side plate Enlargement can actually take place. In addition, since fluid pressure acts on the bottom surface of the vane groove and the inner end surface of the vane, and the step surface facing the axial direction of the rotor, the fluid pressure acting on the bottom surface of the vane groove and the inner end surface of the vane also in this case. Can be reliably acted on the movable side plate in the axial direction of the rotor.

(First embodiment)
Hereinafter, a first embodiment of the vane pump according to the present invention will be described with reference to FIGS. Examples of the application target of the vane pump include, but are not limited to, a fuel pump that supplies fuel to an internal combustion engine, a pump that is used in a power steering device of an automobile, and the like.

1 schematically shows the BB cross section of FIG. 2, and FIG. 2 schematically shows the AA cross section of FIG.
As shown in FIGS. 1 and 2, the vane pump includes a cam ring 12 having a substantially annular shape and having an inner peripheral surface thereof as a cam surface 13. Here, in order to specify the position of the cam surface 13, a 45 ° lower right portion in FIG. 1 is used as a reference position for convenience, and is represented by an angle θ in the counterclockwise direction. The angle θ of the reference position is “θ0”, and the positions where the rotational phase is advanced by 45 ° from this reference position are “θ1”, “θ2”,.

  A distance D (see FIG. 2) from the center C of the cam ring 12 to the cam surface 13 varies depending on the angle θ. The distance D is minimized at a position (reference position) where the angle θ is θ0, and gradually increases as the rotational phase advances (the angle θ increases). The distance D is maximum at a position where the rotation phase is advanced by 90 ° from the reference position (position where the angle θ is θ2). Further, as the rotational phase advances, the distance D decreases gradually. The distance D is minimum at the position where the rotation phase is advanced 180 ° from the reference position (position where the angle θ is θ4), that is, the same as the reference position. The distance D gradually increases again as the rotational phase advances from θ4. The distance D is maximum at a position where the rotational phase is advanced by 270 ° from the reference position (position where the angle θ is θ6). Further, as the rotational phase advances, the distance D decreases gradually. As described above, the change manner of the distance D is the same in each of the region in which the angle θ is θ0 to θ4 and the region in which the angle θ is θ4 to θ0.

  A cylindrical rotor 17 is provided in the cam ring 12. A drive shaft 16 that is driven to rotate by an internal combustion engine or the like is attached to the rotor 17 so as to be integrally rotatable.

  The rotor 17 is provided with a plurality (eight in this case) of vane grooves 24 that are open on the outer peripheral surface and extend toward the center C in the circumferential direction at equal or substantially equal angles. A vane 25 is slidably accommodated in each vane groove 24. Each vane 25 is configured to be pressed against the cam surface 13 by being urged in a direction protruding from the vane groove 24 (radially outward).

A space between the adjacent vanes 25 and surrounded by the cam ring 12 and the rotor 17 constitutes a working chamber 26 (FIG. 1) whose volume changes as the rotor 17 rotates.
In the axial direction of the rotor 17, one side surface (the left side in FIG. 2) of the rotor 17 and the vane 25 is provided to face the one side surface and constitutes a part of the side wall of the working chamber 26. A fixed side plate 2 is provided. The fixed side plate 2 is fixed to one side surface (left side in FIG. 2) of the cam ring 12, and is rotatably supported with the drive shaft 16 penetrating therethrough. The stationary side plate 2 is formed with a suction passage 21 for sucking a fluid such as fuel or oil into the vane pump.

  The other side surface (the right side in FIG. 2) of the rotor 17 and the vane 25 in the axial direction of the rotor 17 is provided to face the other side surface, and can slide in the cam ring 12 in the axial direction of the rotor 17. A movable side plate 30 that is disposed and forms a part of the side wall of the working chamber 26 is provided. The outer peripheral surface of the movable side plate 30 is a cam surface approximated to the inner peripheral shape of the cam ring 12 in order to ensure the airtightness of the working chamber 26 as much as possible. The movable side plate 30 is formed with a hole 30b for pivotally supporting one end of the drive shaft 16 in a rotatable manner.

  A side plate housing 15 is fixed to the other side surface (the right side in FIG. 2) of the cam ring 12. A recess 15 a is formed in the side plate housing 15 so that the movable side plate 30 can slide in the axial direction of the rotor 17. Further, in the same side plate housing 15, a spring 31 for urging the movable side plate 30 toward the fixed side plate 2, in other words, pressing the movable side plate 30 against the rotor 17 and the vane 25 is disposed. The spring 31 may be changed to an appropriate elastic member. Further, a discharge passage 23 for discharging fluid from the vane pump is formed in the side plate housing 15, and the discharge passage 23 communicates with the concave portion 15a. Therefore, back pressure (pressure of fluid discharged from the inside of the vane pump) acts on the surface of the movable side plate 30 opposite to the fixed side plate 2 side, and the movable side plate 30 is also applied to the fixed side plate 2 by this back pressure. It is energized towards.

  As described above, the back pressure chamber 27 is provided at the bottom of each vane groove 24 in order to bias the vane 25 in the direction protruding from the vane groove 24 (outward in the radial direction). The back pressure chamber 27 is formed by a bottom surface 17A of the vane groove 24 and an inner end surface 25B that is in the vane 25 and faces the bottom surface 17A, and the fluid discharged from the working chamber 26 is guided to the back pressure chamber 27. . Accordingly, the pressure of the fluid to be discharged acts on the inner end surface 25B of the vane 25, and the vane 25 is displaced in a direction protruding from the vane groove 24 and is pressed against the cam surface 13.

  In order to suck fluid into the working chamber 26, a groove on the movable side plate 30 that faces the side surface of the vane 25 is a groove that opens toward the side surface of the vane 25, and is formed from the suction passage 21 to the working chamber 26. A movable suction port 19 for sucking fluid is formed. The movable suction port 19 is also substantially arc-shaped and is located at a location corresponding to the working chamber 26 in the radial direction. In the circumferential direction, the cam surface 13 is located in the vicinity of the portion where the angle θ is θ1 and θ5. As described above, the movable-side suction port 19 is located at a position (left and right in FIG. 1) facing each other across the center C.

  Further, a surface of the fixed side plate 2 facing the side surface of the vane 25 is a groove opened toward the side surface of the vane 25, and is a fixed side for sucking fluid from the suction passage 21 into the working chamber 26. A suction port 3 is formed. The fixed suction port 3 has a substantially arc shape, and is located at a position corresponding to the working chamber 26 in the radial direction. In the circumferential direction, the cam surface 13 is located in the vicinity of the portion where the angle θ is θ1 and θ5. As described above, the fixed suction port 3 is located on the opposite sides (left and right in FIG. 1) across the center C, and is always in communication with the movable suction port 19 via the working chamber 26.

  In order to discharge the fluid from the working chamber 26, the surface of the movable side plate 30 that faces the side surface of the vane 25 is a groove opened toward the side surface of the vane 25. A movable discharge port 22 is formed for discharging fluid. The movable discharge port 22 has a substantially arc shape, and is located at a location corresponding to the working chamber 26 in the radial direction. In the circumferential direction, the cam surface 13 is positioned in the vicinity of the angle θ of θ3 and θ7, that is, in the vicinity of the position where the rotational phase is shifted by about 90 ° with respect to the movable suction port 19. . As described above, the movable-side discharge port 22 is located at a position (up and down in FIG. 1) facing each other across the center C. Incidentally, the movable discharge port 22 is communicated with the recess 15 a through a passage formed in the movable plate 30. Therefore, the fluid pressurized in the working chamber 26 is discharged from the discharge passage 23 via the movable discharge port 22, the passage formed in the movable plate 30, and the recess 15 a.

  The fixed side discharge port 4 that discharges fluid from the working chamber 26 to the discharge passage 23 is a groove opened toward the side surface of the vane 25 on the surface of the fixed side plate 2 that faces the side surface of the vane 25. Is formed. The fixed-side discharge port 4 has a substantially arc shape, and is located at a position corresponding to the working chamber 26 in the radial direction. Further, in the circumferential direction, the cam surface 13 is located in the vicinity of the portion where the angles θ are θ3 and θ7. As described above, the fixed-side discharge port 4 is located at the opposite positions (upper and lower sides in FIG. 1) across the center C, and is always in communication with the movable-side discharge port 22 through the working chamber 26.

  In order to introduce the fluid discharged from the working chamber 26 into the back pressure chamber 27, the surface of the movable side plate 30 that faces the side surfaces of the rotor 17 and the vane 25 includes the side surface of the rotor 17 and the vane 25, and A movable-side back pressure introduction groove 28 that is a groove that opens toward the back pressure chamber 27 and that guides the fluid discharged from the working chamber 26 is formed. The movable-side back pressure introduction groove 28 has an annular shape, and is located in the vicinity of a location corresponding to each back pressure chamber 27 in the radial direction. Incidentally, the movable-side back pressure introduction groove 28 is communicated with the concave portion 15 a through a passage formed in the movable-side plate 30. Accordingly, the pressurized fluid introduced into the recess 15 a is introduced into the back pressure chamber 27 via the passage formed in the movable side plate 30 and the movable side back pressure introduction groove 28.

  Further, a surface of the fixed side plate 2 facing the side surfaces of the rotor 17 and the vane 25 is a groove opened toward the side surface of the rotor 17 and the vane 25 and the back pressure chamber 27 and is discharged from the working chamber 26. A fixed-side back pressure introducing groove 5 through which the fluid is guided is formed. The fixed-side back pressure introduction groove 5 is also formed in an annular shape, and is located in the vicinity of a location corresponding to each back pressure chamber 27 in the radial direction. The movable-side back pressure introduction groove 28 and the fixed-side back pressure introduction groove 5 are always in communication with each other through the back pressure chambers 27.

  In the vane pump configured as described above, the volume of the working chamber 26 changes as the drive shaft 16 rotates. The fluid is sucked into the working chamber 26 from the outside through the suction passage 21 and each suction port by the suction force generated as the volume increases. When the rotor 17 accompanying the rotation of the drive shaft 16 causes the rear vane 25 in the rotation direction of the working chamber 26 to pass through each suction port, the working chamber 26 becomes a closed space. Furthermore, the fluid is pressurized as the volume of the working chamber 26 decreases with the rotation of the rotor 17, and the fluid having a high pressure is discharged to the outside through the discharge ports, the recesses 15 a, and the discharge passages 23 described above.

  Incidentally, since the cam surface 13 has a substantially elliptical shape as described above, when the vane 25 slides at a position where the angle θ is θ2 to θ4 and a position where the angle θ6 is θ6 to θ0, the volume of the working chamber 26 is increased. Decrease. In addition, when the vane 25 slides on a position where the angle θ is θ0 to θ2 and a position where the angle θ4 is θ4 to θ6, the volume of the working chamber 26 increases.

  By the way, in the vane pump according to the present embodiment, as illustrated in FIG. 9, the fixed side plate 2 is provided on the side facing the one side of the rotor 17 and the vane 25, and the other side of the rotor 17 and the vane 25. A movable side plate 30 is provided on the side facing the side. Accordingly, the surface of the movable side plate 30 that faces the rotor 17 and the vane 25 slides substantially on the entire side surface of the rotor 17 and the vane 25, so that stepped wear hardly occurs and the clearance is compensated by wear. Easy. However, as described above, stepped wear may occur on the fixed side plate 2 side.

  Therefore, in the present embodiment, by providing a biasing mechanism that biases the rotor 17 and each vane 25 toward the movable side plate 30, generation of stepped wear on the fixed side plate 2 is suppressed.

  In the present embodiment, as shown in FIG. 2, the opening area of the fixed discharge port 4 is formed to be larger than the opening area of the movable discharge port 22. Further, the opening area of the stationary suction port 3 is formed to be larger than the opening area of the movable suction port 19. The biasing mechanism is configured by forming the opening area of the fixed-side back pressure introduction groove 5 to be larger than the opening area of the movable-side back pressure introduction groove 28.

  More specifically, as shown in FIG. 3 (enlarged view of a portion surrounded by a two-dotted line E in FIG. 2), the fixing formed on the side surface 2A that is on the fixed side plate 2 and faces the side surface 25E of the vane 25. The groove width of the side discharge port 4 is larger than the groove width of the movable side discharge port 22 formed on the side surface 30 </ b> A of the movable side plate 30 facing the side surface 25 </ b> F of the vane 25. Accordingly, the pressure receiving area on the side surface 25E of the vane 25 on which the fluid pressure in the fixed discharge port 4 acts is larger than the pressure receiving area on the side surface 25F of the vane 25 on which the fluid pressure in the movable discharge port 22 acts. The force F1A for energizing the vane 25 toward the movable side plate 30 becomes larger than the force F2A for energizing the vane 25 toward the fixed side plate 2. Therefore, the vane 25 is urged toward the movable side plate 30.

  Further, the groove width of the fixed-side back pressure introducing groove 5 formed on the side surface 2A facing the side surface 25E of the vane 25 on the fixed side plate 2 is the side surface 30A facing the side surface 25F of the vane 25 on the movable side plate 30. It is made larger than the groove width of the movable side back pressure introduction groove 28 formed in. Accordingly, the pressure receiving area on the side surface 25E of the vane 25 on which the fluid pressure in the fixed-side back pressure introduction groove 5 acts is the fluid pressure on the side surface 25F of the vane 25 and on the movable-side back pressure introduction groove 28. The force F1B that urges the vane 25 toward the movable side plate 30 becomes larger than the force F2B that urges the vane 25 toward the fixed side plate 2 because it is larger than the pressure receiving area. Therefore, the vane 25 is urged toward the movable side plate 30. The fixed-side back pressure introduction groove 5 is located on the side surface 2 </ b> A and opens toward the side surface 25 </ b> E of the vane 25 and the side surface 17 </ b> S of the rotor 17. Therefore, the fluid pressure in the fixed-side back pressure introduction groove 5 acts on the side surface 17S of the rotor 17, and the force F1C that urges the rotor 17 toward the movable side plate 30 acts on the side surface 17S. Accordingly, the rotor 17 is also biased toward the movable side plate 30.

  Thus, the force F1 (= F1A + F1B + F1C) for urging each vane 25 or rotor 17 toward the movable side plate 30 is the force F2 (= F2A + F2B) for urging each vane 25 or rotor 17 toward the movable side plate 30. And the vanes 25 and the rotor 17 are urged toward the movable side plate 30. Therefore, the rotor 17 and each vane 25 are slid mainly on the movable side plate 30 side, and sliding between the rotor 17 and each vane 25 and the fixed side plate 2 is suppressed. Therefore, the occurrence of stepped wear on the fixed side plate 2 is suppressed. Therefore, an increase in the clearance between the side surface 25E of the vane 25 and the side surface 2A of the fixed side plate 2 is suppressed, and an increase in the amount of fluid leakage from the clearance is also suppressed, thereby suppressing a decrease in volumetric efficiency of the pump. become able to.

  As shown in FIG. 2, the groove width of the fixed side suction port 3 formed on the fixed side plate 2 is also larger than the groove width of the movable side suction port 19 formed on the movable side plate 30. Accordingly, the vane 25 positioned between the fixed suction port 3 and the movable suction port 19 is also urged toward the movable plate 30 in the same manner.

  Further, a force F <b> 3 that urges the movable side plate 30 toward the fixed side plate 2 acts on the movable side plate 30. This force F3 is caused by the urging force of the spring 31 and the back pressure (pressure of the fluid discharged from the pump) applied from the recess 15a. Further, although the back pressure in the recess 15a acts on the side surface in the axial direction of the rotor 17 in the movable side plate 30, the pressure receiving area is considerably larger than the pressure receiving areas of the rotor 17 and the vane 25 that generate the force F1. Is. Accordingly, the force F3 is larger than the sum of the forces F1 and F2 described above.

  Therefore, according to this embodiment, although the movable side plate 30 is worn, an increase in clearance due to this wear, that is, an increase in the clearance between the side surface 25F of the vane 25 and the side surface 30A of the movable side plate 30 is caused by the movable side plate. 30 is compensated for by moving toward the fixed side plate 2. Accordingly, a decrease in volumetric efficiency due to wear of the movable side plate 30 is also suppressed. Further, the movement of the movable side plate 30 toward the fixed side plate 2 allows the clearance between the side surface 25E of the vane 25 and the side surface 2A of the fixed side plate 2 (the clearance on the fixed side plate 2 side) or the side surface 25F of the vane 25 to move. The clearance between the side plate 30 and the side surface 30A (the clearance on the movable side plate 30 side) can also be made sufficiently small. Therefore, this also makes it possible to suppress an increase in the amount of fluid leakage from each clearance.

As described above, according to the vane pump described in the present embodiment, the following effects can be obtained.
(1) The fixed side plate 2 is provided so as to face one side surface of the rotor 17 and the vane 25 in the axial direction of the rotor 17 and constitutes a part of the side wall of the working chamber 26. Further, it is provided opposite to the other side surface of the rotor 17 and the vane 25 in the axial direction of the rotor 17, can slide in the cam ring 12 in the axial direction of the rotor 17, and is urged toward the fixed side plate 2. The movable side plate 30 constituting a part of the side wall of the working chamber 26 is provided. A biasing mechanism that biases the rotor 17 and the vanes 25 toward the movable side plate 30 is provided. Accordingly, the rotor 17 and the vane 25 are urged toward the movable side plate 30. Therefore, the side surfaces of the rotor 17 and the vane 25 slide mainly on the movable side plate 30 side, and the sliding between the rotor 17 and the vane 25 and the fixed side plate 2 is suppressed. Therefore, the occurrence of stepped wear on the fixed side plate 2 is suppressed, and a decrease in volumetric efficiency of the pump can be suitably suppressed.

  Incidentally, although the movable side plate 30 is worn in the above embodiment, the increase in the clearance due to this wear is compensated by the movement of the movable side plate 30 toward the fixed side plate 2. Accordingly, a decrease in volumetric efficiency due to wear of the movable side plate 30 is also suppressed.

(2) As the urging mechanism, the opening area of the fixed-side discharge port 4 is formed larger than the opening area of the movable-side discharge port 22, and the opening area of the fixed-side suction port 3 is larger than the opening area of the movable-side suction port 19. The opening area of the fixed-side back pressure introduction groove 5 is formed larger than the opening area of the movable-side back pressure introduction groove 28. Therefore, the pressure receiving area of the fluid pressure on one side surface of the rotor 17 and the vane 25 facing the fixed side plate 2 is larger than the pressure receiving area of the fluid pressure on the other side surface of the rotor 17 and the vane 25 facing the movable side plate 30. The rotor 17 and the vane 25 are urged toward the movable side plate 30 by this pressure receiving area difference. Therefore, the rotor 17 and the vane 25 can be reliably urged toward the movable side plate 30.
(Second Embodiment)
Next, a second embodiment of the vane pump according to the present invention will be described with reference to FIGS.

  In the present embodiment, the fixed discharge port 4 has the same groove width as the movable discharge port 22, and the fixed back pressure introduction groove 5 has the same groove width as the movable back pressure introduction groove 28. . Further, the opening area of the stationary suction port 3 with respect to one side surface of the vane 25 is made the same as the opening area of the movable suction port 19 with respect to the other side surface of the vane 25. Accordingly, the fixed-side discharge port 4 is substantially the same as the movable-side discharge port 22, the fixed-side back pressure introduction groove 5 is the same as the movable-side back pressure introduction groove 28, and the fixed-side suction port 3 is movable. It is the same as the side suction port 19. Further, the biasing mechanism as described above is provided on one side of the rotor and the vane facing the fixed side plate, is opened toward the fixed side plate, and is formed by a step portion formed so as to communicate with the back pressure chamber. This configuration is basically the same as the first embodiment except for these differences. Therefore, in the following, the vane pump in this embodiment will be described focusing on these differences.

  FIG. 4 shows the AA cross-sectional structure of the vane pump according to the present embodiment as shown in FIG. In the present embodiment, a step portion 25C provided on one side surface of the vane 25 facing the fixed side plate 2 and opened toward the fixed side plate 2 and communicated with the back pressure chamber 27, and the fixed side plate A biasing mechanism is configured by a step portion 17 </ b> B provided on one side surface of the rotor 17 facing 2, opened toward the fixed side plate 2, and formed to communicate with the back pressure chamber 27.

  More specifically, as shown in FIG. 5 (enlarged view of the portion surrounded by the two-dotted line F in FIG. 4), the side surface 25E of the vane 25 facing the fixed side plate 2 opens toward the fixed side plate 2. In addition, a step portion 25 </ b> C formed so as to communicate with the back pressure chamber 27 is formed. Accordingly, the fluid pressure in the back pressure chamber 27 acts on the step portion 25C, and as a result, a force F1D that biases the vane 25 toward the movable side plate 30 is generated, and the vane 25 is directed toward the movable side plate 30. Is energized.

  Further, on the side surface of the rotor 17 that faces the fixed side plate 2, a step portion 17 </ b> B that is open toward the fixed side plate 2 and is formed so as to communicate with the back pressure chamber 27 is formed. Accordingly, the fluid pressure in the back pressure chamber 27 acts on the stepped portion 17B, and as a result, a force F1E that urges the rotor 17 toward the movable side plate 30 is generated, and the rotor 17 is directed toward the movable side plate 30. Is energized.

  Thus, since each vane 25 and the rotor 17 are also urged | biased toward the movable side plate 30 also by the urging | biasing mechanism concerning this embodiment, the effect similar to the said 1st Embodiment can be acquired.

Incidentally, the back pressure in the recess 15a acts on the side surface in the axial direction of the rotor 17 in the movable side plate 30, but the pressure receiving area thereof is the force F1 that urges the rotor 17 and the vane 25 toward the movable side plate 30 side. The pressure receiving area of the step portion 25C and the step portion 17B that generate (= F1D + F1E) is considerably larger. Therefore, also in this embodiment, the force F3 for urging the movable side plate 30 toward the fixed side plate 2 is larger than the force F1 for urging the rotor 17 and the vane 25 toward the movable side plate 30. For the same reason as the form, a decrease in volumetric efficiency due to wear of the movable side plate 30 is suppressed. Further, the clearance between the side surface 25E of the vane 25 and the side surface 2A of the fixed side plate 2 (clearance on the fixed side plate 2 side) and the clearance between the side surface 25F of the vane 25 and the side surface 30A of the movable side plate 30 (on the movable side plate 30 side). (Clearance) can be made sufficiently small. Therefore, this also makes it possible to suppress an increase in the amount of fluid leakage from each clearance.
(Third embodiment)
Next, a third embodiment of the vane pump according to the present invention will be described with reference to FIGS.

  In the present embodiment, the fixed discharge port 4 has the same groove width as the movable discharge port 22, and the fixed back pressure introduction groove 5 has the same groove width as the movable back pressure introduction groove 28. . Further, the opening area of the stationary suction port 3 with respect to one side surface of the vane 25 is made the same as the opening area of the movable suction port 19 with respect to the other side surface of the vane 25. Accordingly, the fixed-side discharge port 4 is substantially the same as the movable-side discharge port 22, the fixed-side back pressure introduction groove 5 is the same as the movable-side back pressure introduction groove 28, and the fixed-side suction port 3 is movable. It is the same as the side suction port 19. Further, the urging mechanism as described above is composed of the bottom surface of the vane groove and the inner end surface of the vane formed so that the back pressure chamber expands toward the fixed side plate. In particular, this is the same as the first embodiment. Therefore, in the following, the vane pump in this embodiment will be described focusing on these differences.

  FIG. 6 shows the AA cross-sectional structure of the vane pump according to this embodiment as shown in FIG. As shown in FIG. 6, in this embodiment, the back pressure chamber 6 provided at the bottom of each vane groove 24 is directed toward the fixed side plate 2 in order to urge the vane 25 in a direction protruding from the vane groove 24. It has been expanded.

  More specifically, as shown in FIG. 7 (enlarged view of the portion surrounded by the two-dot chain line G in FIG. 6), the bottom surface 17C of the vane groove 24 forming the back pressure chamber 6 and the vane 25 An inner end surface 25D facing the bottom surface 17C is formed as an inclined surface, and the biasing mechanism in the present embodiment is constituted by the inclined bottom surface 17C and the inner end surface 25D.

  The pressure of the fluid introduced into the back pressure chamber 6, that is, the fluid pressure F1G acts on the inner end face 25D. Here, since the inner end face 25D is an inclined surface, as shown in FIG. 7, the fluid pressure F1G is decomposed according to the inclination angle, and a part thereof is in the axial direction of the rotor 17, and the movable side plate 30 The component force F1G ′ acting toward Accordingly, the inner end face 25 </ b> D is biased toward the movable side plate 30 by the component force F <b> 1 </ b> G ′, and the vane 25 is biased toward the movable side plate 30.

  Similarly, the pressure of the fluid introduced into the back pressure chamber 6, that is, the fluid pressure F1H (= F1G) also acts on the bottom surface 17C. Here, since the bottom surface 17C is also an inclined surface, as shown in FIG. 7, the fluid pressure F1H is decomposed according to the inclination angle, and a part thereof is in the axial direction of the rotor 17 and is moved to the movable side plate 30. It becomes the component force F1H 'which acts toward. Therefore, the bottom surface 17 </ b> C is biased toward the movable side plate 30 by the component force F <b> 1 </ b> H ′, and thus the rotor 17 is biased toward the movable side plate 30.

  Thus, since each vane 25 and the rotor 17 are also urged | biased toward the movable side plate 30 also by the urging | biasing mechanism concerning this embodiment, the effect similar to the said 1st Embodiment can be acquired.

  Incidentally, the back pressure in the recess 15a acts on the side surface in the axial direction of the rotor 17 in the movable side plate 30, but the pressure receiving area thereof is the force F1 that urges the rotor 17 and the vane 25 toward the movable side plate 30 side. It is much larger than the pressure receiving area of the bottom surface 17C and the inner end surface 25D that generate (= F1G ′ + F1H ′). Therefore, also in this embodiment, the force F3 for urging the movable side plate 30 toward the fixed side plate 2 is larger than the force F1 for urging the rotor 17 and the vane 25 toward the movable side plate 30. For the same reason as the form, a decrease in volumetric efficiency due to wear of the movable side plate 30 is suppressed. Further, the clearance between the side surface 25E of the vane 25 and the side surface 2A of the fixed side plate 2 (clearance on the fixed side plate 2 side) and the clearance between the side surface 25F of the vane 25 and the side surface 30A of the movable side plate 30 (on the movable side plate 30 side). (Clearance) can be made sufficiently small. Therefore, this also makes it possible to suppress an increase in the amount of fluid leakage from each clearance.

In addition, each said embodiment can also be changed and implemented as follows.
The urging mechanism in the first embodiment and the urging mechanism in the second embodiment can be combined. Further, the urging mechanism in the second embodiment and the urging mechanism in the third embodiment can be combined. Further, the urging mechanism in the first embodiment and the urging mechanism in the third embodiment may be combined. Furthermore, the urging mechanism in the first embodiment, the urging mechanism in the second embodiment, and the urging mechanism in the third embodiment may be combined.

  In the third embodiment, the bottom surface 17C of the vane groove 24 and the inner end surface 25D of the vane 25 are formed as inclined surfaces, but they may be formed as stepped surfaces. For example, as illustrated in FIG. 8, the urging mechanism includes the bottom surface 17 </ b> C ′ of the vane groove 24 formed in a step shape so that the back pressure chamber 6 ′ expands toward the fixed side plate 2 and the vane 25. It is comprised by end surface 25D '. In this case, since fluid pressure acts on the step surface facing the axial direction of the rotor 17 on the bottom surface 17C ′ and the inner end surface 25D ′, the rotor 17 and the vane 25 are attached to the movable side plate 30 on the step surface. A force F1J that urges toward the surface acts. Accordingly, in this case as well, the fluid pressure acting on the bottom surface 17C ′ and the inner end surface 25D ′ can be reliably applied toward the movable side plate 30 in the axial direction of the rotor 17, and thus the rotor 17 and the vane. 25 can be urged toward the movable side plate 30. Incidentally, the number of steps of the bottom surface 17C 'and the inner end surface 25D' shown in FIG. 8 is merely an example, and this can be implemented with appropriate changes.

  The present invention can also be applied to a vane pump of a type provided with a spring that biases the vane groove 24 in the direction in which the vane 25 protrudes.

1 is a schematic sectional view showing a first embodiment of a vane pump according to the present invention. AA sectional drawing in FIG. FIG. 3 is an enlarged view of a portion surrounded by a two-dot difference line E in FIG. Sectional drawing which shows the structure of the vane pump concerning 2nd Embodiment. FIG. 4 is an enlarged view of a portion surrounded by a two-dot difference line F in FIG. 4. Sectional drawing which shows the structure of the vane pump concerning 3rd Embodiment. FIG. 6 is an enlarged view of a portion surrounded by a two-dot difference line G in FIG. 6. The expanded sectional view which shows the structure about the vane pump concerning the modification of 3rd Embodiment. Schematic which shows the cross-section of the rotating shaft direction about a vane pump provided with a movable side plate.

Explanation of symbols

  2 ... fixed side plate, 2A ... side surface, 3 ... fixed side suction port, 4 ... fixed side discharge port, 5 ... fixed side back pressure introduction groove, 6, 6 '... back pressure chamber, 12 ... cam ring, 13 ... cam surface, DESCRIPTION OF SYMBOLS 15 ... Side plate housing, 15a ... Recess, 16 ... Drive shaft, 17 ... Rotor, 17A ... Bottom, 17B ... Step part, 17C, 17C '... Bottom, 17S ... Side, 19 ... Movable suction port, 21 ... Suction passage, 22 ... movable side discharge port, 23 ... discharge passage, 24 ... vane groove, 25 ... vane, 25B ... inner end face, 25C ... stepped portion, 25D, 25D '... inner end face, 25E ... side face, 25F ... side face, 26 ... actuated 27, back pressure chamber, 28 ... movable side back pressure introduction groove, 30 ... movable side plate, 30A ... side surface, 30b ... hole, 31 ... spring.

Claims (6)

A cam ring, a rotor provided in the cam ring, and a plurality of vanes provided in a plurality of vane grooves opened on an outer peripheral surface of the rotor and sliding on the cam surface in the cam ring as the rotor rotates. And a plurality of working chambers partitioned between adjacent vanes, and fluid is sucked from the suction passage into the working chamber by the volume change of each working chamber accompanying the rotation of the rotor, In a vane pump that discharges fluid in a pressurized state,
A fixed side plate provided facing one side surface of the rotor and the vane in the axial direction of the rotor, and constituting a part of a side wall of the working chamber;
A part of the side wall of the working chamber is provided opposite to the other side surface of the rotor and the vane, is slidable in the cam ring in the axial direction of the rotor, and is biased toward the fixed side plate. A movable side plate comprising:
A vane pump comprising: an urging mechanism that urges the rotor and the vane toward the movable side plate. A back pressure chamber is provided at the bottom of the vane groove to guide the fluid discharged from the working chamber,
A fixed-side discharge that discharges the fluid from the working chamber to the discharge passage is a groove that opens toward the side surface of the vane on a surface of the fixed-side plate that faces the side surface of the rotor and the vane. A port, a groove opened toward a side surface of the vane, and a fixed-side suction port for sucking the fluid from the suction passage into the working chamber; a side surface of the rotor and the vane; and a back pressure chamber A fixed-side back pressure introduction groove, which is a groove that is open toward the side and that guides the fluid discharged from the working chamber,
In the movable side plate, a surface facing the side surface of the rotor and the vane is a groove opened toward the side surface of the vane, and the movable side discharge discharges the fluid from the working chamber to the discharge passage. A port, a groove opened toward a side surface of the vane, and a movable-side suction port for sucking the fluid from the suction passage into the working chamber; a side surface of the rotor and the vane; and a back pressure chamber A movable-side back pressure introduction groove that is a groove that is opened toward the fluid discharge direction from the working chamber is formed;
The biasing mechanism is formed such that an opening area of the fixed discharge port is larger than an opening area of the movable discharge port, and an opening area of the fixed suction port is larger than an opening area of the movable suction port. The vane pump according to claim 1, wherein the vane pump is configured such that an opening area of the fixed-side back pressure introduction groove is larger than an opening area of the movable-side back pressure introduction groove. A back pressure chamber is provided at the bottom of the vane groove to guide the fluid discharged from the working chamber,
The urging mechanism is provided on one side surface of the rotor and the vane facing the fixed side plate, is opened toward the fixed side plate, and is formed by a step portion formed so as to communicate with the back pressure chamber. The vane pump according to claim 1 constituted. At the bottom of the vane groove, a back pressure chamber is provided which is formed by a bottom surface of the vane groove and an inner end surface of the vane facing the bottom surface and into which the fluid discharged from the working chamber is guided. ,
The vane pump according to claim 1, wherein the urging mechanism is configured by the bottom surface and the inner end surface formed so that the back pressure chamber expands toward the fixed side plate. The vane pump according to claim 4, wherein a bottom surface of the vane groove and an inner end surface of the vane are formed as inclined surfaces. The vane pump according to claim 4, wherein a bottom surface of the vane groove and an inner end surface of the vane are formed in a stepped shape.

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