JP2020041465A - Vane pump - Google Patents

Abstract

To improve volume efficiency of a vane pump.SOLUTION: A vane pump 100 comprises: a rotor 20; a vane 130 housed in a slit 22 opened on an outer periphery of the rotor 20; a cam ring 40 in slide contact with the vane 130 together with rotation of the rotor 20; a pair of side members 60, 70 sandwiching the rotor 20 and the cam ring 40; a pump chamber 41 defined by the rotor 20, the cam ring 40, the adjacent bane 130, and a pair of the side members 60, 70; suction ports 81, 82 for introducing working fluid sucked by the pump chamber 41; an emission port 72 for introducing the working fluid emitted from the pump chamber 41; and a concave part 110 provided on a front side face of the vane 130 in a rotation direction. The concave part 110 has an inner wall 112 directed to the rotor 20 on a front side in the rotation direction of the vane 130. The inner wall 112 is exposed from the slit 22 in suction regions 42a, 42c in which a capacity of the pump chamber 41 is expanded.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a vane pump.

  Patent Literature 1 discloses a vane pump including a rotor that is driven to rotate and a vane that slides in a slit of the rotor. Each vane is urged in a direction to protrude from the slit by the pressure of the slit bottom pressing the base end thereof and the centrifugal force acting with the rotation of the rotor, and the tip end slides on the inner peripheral surface of the cam ring. Touch The pump chamber expands and contracts, and hydraulic oil is supplied and discharged to and from the pump chamber by reciprocating the vane slidingly contacting the inner peripheral surface of the cam ring with the rotation of the rotor.

JP-A-11-230057

  In recent years, there has been a demand for higher rotational speeds of vane pumps. However, in the vane pump described in Patent Literature 1, when the vane pump is rotated at a high speed, in the process of sucking the working fluid into the pump chamber, a part of the sucked working fluid may be discharged to the outside of the pump chamber again. For this reason, it is required to suppress a decrease in the suction amount of the working fluid into the pump chamber at the time of high-speed rotation and to improve the volumetric efficiency of the vane pump.

  The present invention has been made in view of the above problems, and has as its object to increase the suction amount of a working fluid into a pump chamber and improve the volumetric efficiency of a vane pump.

  The present invention relates to a vane pump, which includes a rotor, a plurality of slits opened on an outer peripheral surface of the rotor, a plurality of vanes slidably housed in the slits, and tips of the plurality of vanes with rotation of the rotor. A cam ring having an inner peripheral cam surface with which the portion slides, a pair of side members arranged so as to sandwich the rotor and the cam ring, a rotor, a cam ring, an adjacent vane, a pump chamber defined by the pair of side members, A suction port that guides a working fluid sucked into the pump chamber; a discharge port that guides a working fluid discharged from the pump chamber; and a recess provided on a surface on the front side in the rotation direction of the vane. Direction, and has an inner wall surface facing the rotor side, and the inner wall surface is exposed from the slit at least in a suction area where the volume of the pump chamber is expanded. And wherein the door.

  According to the present invention, since the inner wall surface of the concave portion can generate a flow inward in the radial direction while being along the circumferential direction, the working fluid is discharged out of the pump chamber in the process of sucking the working fluid into the pump chamber. Can be suppressed.

  According to the present invention, the inner wall surface is inclined such that the wall thickness of the vane is increased toward the tip end side of the vane, or the thickness of the vane is increased toward the tip end side of the vane. It is characterized by being a curved surface that curves in a curved manner.

  According to the present invention, the discharge of the working fluid to the outside of the pump chamber can be suppressed with a simple configuration.

  According to the present invention, the cam ring is provided with a cutout portion penetrating from the outer peripheral surface to the inner peripheral cam surface so as to constitute a part of the suction port, and the inner wall surface is formed with the front end portion of the vane interposed therebetween. A first inner wall surface radially opposed to the peripheral cam surface; and a second inner wall surface radially opposed to the notch portion with the tip end of the vane interposed therebetween, and the second inner wall surface has a notch portion. And a guiding surface for guiding the working fluid toward the first inner wall surface.

  According to the present invention, the flow of the working fluid toward the cutout portion is controlled by the inner peripheral cam by the cutout portion forming a part of the suction port and the guide surface provided at a position radially opposite to each other across the tip end portion of the vane. It can be guided toward a surface. For this reason, in the process of sucking the working fluid into the pump chamber, it is possible to suppress the working fluid from being discharged from the pump chamber to the cutout portion.

  The present invention is characterized in that the vane is arranged such that the tip end thereof is located forward of the base end in the rotation direction of the vane.

  In the present invention, the vane protrudes forward from the slit in the rotation direction. For this reason, in the process of sucking the working fluid into the pump chamber, it is possible to suppress the working fluid from being discharged to the outside of the pump chamber by using the entire surface on the front side in the rotation direction of the vane, including the concave portion.

  The present invention is characterized in that the wall thickness of both sides in the axial direction of the concave portion in the vane is larger than the wall thickness in the concave portion.

  According to the present invention, the rigidity of the vane can be increased.

  ADVANTAGE OF THE INVENTION According to this invention, the suction amount of the working fluid into a pump chamber can be increased, and the volumetric efficiency of a vane pump can be improved.

FIG. 1 is a sectional view of the vane pump according to the first embodiment of the present invention. FIG. 2 is a front view of the rotor, the vane, and the cam ring, and shows a state where the rotor, the vane, and the cam ring are assembled. FIG. 3 is a front view of the side plate. FIG. 4 is a front view of the vane according to the first embodiment of the present invention. FIG. 5 is a sectional view taken along line VV of FIG. FIG. 6 is a diagram illustrating the flow of hydraulic oil when the vane pump operates. FIG. 7 is a diagram illustrating a recess of a vane in a vane pump according to a modification of the first embodiment of the present invention. FIG. 8 is a front view of the vane according to the second embodiment of the present invention. FIG. 9A is a sectional view taken along line IXa-IXa in FIG. FIG. 9B is a sectional view taken along line IXb-IXb in FIG. FIG. 10A is a cross-sectional view of an end-side concave portion of a vane in a vane pump according to a modification of the second embodiment of the present invention. FIG. 10B is a sectional view of a central concave portion of a vane in a vane pump according to a modification of the second embodiment of the present invention. FIG. 11 is a diagram illustrating the arrangement of vanes in the vane pump according to the first modification. FIG. 12 is a cross-sectional view of the vane in the vane pump according to the second modification.

  Hereinafter, a vane pump according to an embodiment of the present invention will be described with reference to the drawings. The vane pump is used as a fluid pressure supply source of a fluid pressure device (for example, a power steering device or a transmission) mounted on a vehicle. Here, a vane pump using a working oil as the working fluid will be described, but another fluid such as working water may be used as the working fluid.

<First embodiment>
A vane pump 100 according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of the vane pump 100. FIG. 2 is a front view of the rotor 20, the vane 130, and the cam ring 40, and shows a state where the rotor 20, the vane 130, and the cam ring 40 are assembled.

  As shown in FIGS. 1 and 2, the vane pump 100 includes a drive shaft 10, a rotor 20 connected to the drive shaft 10 and driven to rotate, a plurality of slits 22 opened on the outer peripheral surface of the rotor 20, and a slit 22. A plurality of vanes 130 slidably housed, a cam ring 40 accommodating the rotor 20 and the vanes 130, a pump body 50 holding the cam ring 40, and a pump body 50 mounted on the pump body 50 so as to cover an opening of the pump body 50. And a pump cover 60 to be used.

  The drive shaft 10 is rotatably supported by the pump body 50 and the pump cover 60. When power of an engine or an electric motor (not shown) is transmitted to the drive shaft 10, the rotor 20 rotates with the rotation of the drive shaft 10.

  Hereinafter, the direction along the rotation axis of the rotor 20 is referred to as “axial direction”, the radial direction about the rotation axis of the rotor 20 as “radial direction”, and the direction in which the rotor 20 rotates when the vane pump 100 operates. This is referred to as “rotation direction”.

  The vane pump 100 further includes a side plate 70 that sandwiches the rotor 20 and the cam ring 40 with the pump cover 60 in the axial direction. The rotor 20 and the cam ring 40 are sandwiched between the pump cover 60 and the side plate 70. That is, the pump cover 60 and the side plate 70 constitute a pair of side members arranged so as to sandwich the rotor 20 and the cam ring 40.

  The pump cover 60 has a side surface 60a that contacts the rotor 20 and the cam ring 40, and the side plate 70 has a side surface 70a that contacts the rotor 20 and the cam ring 40. The pump chamber 41 is defined by the rotor 20, the cam ring 40, the adjacent vanes 130, the pump cover 60 as the first side member, and the side plate 70 as the second side member.

  As shown in FIG. 2, a plurality of slits 22 having openings 21 on the outer peripheral surface are formed radially at predetermined intervals in the rotor 20. The opening 21 of the slit 22 is formed in a raised portion 23 that protrudes radially outward from the outer periphery of the rotor 20. That is, the raised portions 23 are formed on the outer periphery of the rotor 20 by the number of the slits 22.

  The vane 130 is slidably inserted into each slit 22. The tip 31 of the vane 130 faces the inner peripheral cam surface 40 a of the cam ring 40. The base end 32 of the vane 130 is located inside the slit 22, and the back pressure chamber 24 is formed by the slit 22 and the vane 130.

  When the rotor 20 rotates, a centrifugal force is generated in the vane 130. By this centrifugal force, the vane 130 is urged in a direction protruding from the slit 22. The vane 130 projects from the slit 22 in the urged state, and the distal end 31 of the vane 130 contacts the inner peripheral cam surface 40 a of the cam ring 40.

  The inner peripheral cam surface 40a is a surface on which the tip portions 31 of the plurality of vanes 130 slide in contact with the rotation of the rotor 20, and is formed in a substantially elliptical shape. Therefore, when the rotor 20 rotates, the vane 130 reciprocates in the radial direction with respect to the rotor 20. As the vane 130 reciprocates, the pump chamber 41 repeats expansion and contraction.

  In the vane pump 100 according to the present embodiment, while the rotor 20 makes one rotation, the vane 130 reciprocates twice, and the pump chamber 41 repeats expansion and contraction twice. That is, the vane pump 100 has two expansion regions 42a and 42c in which the pump chamber 41 expands and two contraction regions 42b and 42d in which the pump chamber 41 contracts alternately in the rotation direction.

  As shown in FIG. 1, the pump body 50 is formed with a housing recess 51 for housing the rotor 20, the cam ring 40, and the side plate 70. The side plate 70 is arranged on the bottom surface 51 a of the accommodation recess 51.

  An annular groove 52 is formed on the bottom surface 51 a of the accommodation recess 51. The annular groove 52 and the side plate 70 define a high-pressure chamber 53 into which the hydraulic oil discharged from the pump chamber 41 flows. The high-pressure chamber 53 is connected to the hydraulic device 1 (for example, a power steering device or a transmission) via the discharge passage 4. Therefore, the hydraulic oil discharged from the pump chamber 41 is supplied to the hydraulic device 1 through the high-pressure chamber 53 and the discharge passage 4.

  FIG. 3 is a front view of the side plate 70 when the side plate 70 is viewed from the cam ring 40 side. As shown in FIGS. 1 and 3, the side plate 70 is formed in an annular shape having a hole 71. The drive shaft 10 is inserted through the hole 71.

  The side plate 70 is provided with two discharge ports 72 for guiding hydraulic oil discharged from the pump chamber 41 to the high-pressure chamber 53. The discharge port 72 is located in each of the contraction regions 42b and 42d.

  As shown in FIG. 2, while the pump chamber 41 passes through the contraction areas 42b and 42d, the pump chamber 41 contracts. The pressure in the pump chamber 41 increases with the contraction of the pump chamber 41, and the hydraulic oil in the pump chamber 41 is discharged from the discharge port 72 to the high-pressure chamber 53 (see FIG. 1). That is, the hydraulic oil in the pump chamber 41 is discharged from the discharge port 72 while the pump chamber 41 passes through the contraction regions 42b and 42d. As described above, since the hydraulic oil is discharged in the contraction regions 42b and 42d, the contraction regions 42b and 42d are also referred to as “discharge regions”.

  The vane 130 is pushed into the slit 22 most when moving from the contracted area 42d to the expanded area 42a and when moving from the contracted area 42b to the expanded area 42c. At this time, the volume of the pump chamber 41 is minimized.

  As shown in FIG. 3, two back pressure passages 73 are formed in the side plate 70 for guiding hydraulic oil from the high pressure chamber 53 (see FIG. 1) to the back pressure chamber 24 (see FIGS. 1 and 2). The back pressure passage 73 has an arc shape centered on the hole 71 and is located in the extension regions 42a and 42c. Therefore, hydraulic oil is guided from the high pressure chamber 53 to the back pressure chamber 24 passing through the expansion regions 42a and 42c. The vanes 130 passing through the expansion regions 42a and 42c are pressed in a direction protruding from the slits 22 (see FIG. 2) by the pressure in the back pressure chamber 24.

  As described above, in the vane pump 100, the vane 130 is urged in the direction protruding from the slit 22 not only by the centrifugal force generated by the rotation of the rotor 20, but also by the pressure in the back pressure chamber 24.

  As shown in FIG. 1, the pump body 50 is provided with a plurality of recesses 54 that are recessed radially outward from the housing recess 51. Further, the pump body 50 is provided with an annular groove 55 communicating with the plurality of recesses 54. The openings of the accommodation recess 51, the recess 54, and the annular groove 55 are sealed by the pump cover 60.

  The pump cover 60 is fastened to the pump body 50 by bolts (not shown). A low-pressure chamber 61 is defined by the outer peripheral surface of the cam ring 40, the pump cover 60, the concave portion 54 and the annular groove 55 of the pump body 50. The low pressure chamber 61 is connected to the tank 2 via the suction passage 3. Therefore, when the vane pump 100 operates, the hydraulic oil in the tank 2 is guided to the pump chamber 41 through the suction passage 3 and the low-pressure chamber 61.

  As shown in FIGS. 1 and 2, the cam ring 40 is provided with notches 40c and 40d penetrating from the outer peripheral surface to the inner peripheral cam surface 40a. The cutout portion 40c opens on a side surface that contacts the pump cover 60, and the cutout portion 40d opens on a side surface that contacts the side plate 70. The notch 40c and the pump cover 60 define a first suction port 81 for guiding hydraulic oil sucked into the pump chamber 41 from the low-pressure chamber 61. The first suction port 81 is formed by the notch 40d and the side plate 70 from the low-pressure chamber 61. A second suction port 82 for guiding hydraulic oil sucked into the pump chamber 41 is defined. That is, the notch 40c forms a part of the first suction port 81, and the notch 40d forms a part of the second suction port 82. The 1st suction port 81 and the 2nd suction port 82 are located in each expansion area 42a, 42c.

  While the pump chamber 41 passes through the expansion areas 42a and 42c (see FIG. 2), the pump chamber 41 expands. As the pump chamber 41 expands, the pressure in the pump chamber 41 decreases, and hydraulic oil is sucked into the pump chamber 41 from the first suction port 81 and the second suction port 82. That is, the hydraulic oil is sucked into the pump chamber 41 from the first suction port 81 and the second suction port 82 while the pump chamber 41 passes through the expansion areas 42a and 42c. As described above, since the operating oil is sucked into the pump chamber 41 in the expansion regions 42a and 42c, the expansion regions 42a and 42c are also referred to as “suction regions”.

  The recess 110 formed in the vane 130 will be described with reference to FIGS. FIG. 4 is a front view of the vane 130 as viewed from the front side in the rotation direction, and FIG. 5 is a cross-sectional view taken along line VV of FIG. The vane 130 is a flat plate-shaped member, and a concave portion 110 is provided on a surface on the front side in the rotation direction of the vane 130. The concave portion 110 forms a trapezoidal column-shaped space in which the front side in the rotation direction of the vane 130 is a rectangular opening surface and the bottom surface 111 is a rectangular flat surface smaller than the area of the opening surface.

  The recess 110 has a rectangular bottom surface 111, a distal inner wall surface 112 extending from the distal end of the vane 130 toward the distal end of the vane 130 at the bottom 111, and a proximal end of the vane 130 at the bottom 111. It has a base end side inner wall surface 113 extending toward the base end side of the vane 130, and a pair of vertical surfaces 114 rising vertically from both axial ends of the bottom surface 111.

  The distal inner wall surface 112 is a flat inclined surface that is inclined such that the thickness t of the vane 130 increases from the bottom surface 111 toward the distal end side of the vane 130. The proximal inner wall surface 113 is an inclined surface that is inclined so that the thickness t of the vane 130 increases from the bottom surface 111 toward the proximal end of the vane 130.

  The thickness t1 of the vane 130 on the bottom surface 111 is smaller than the thickness t2 of the distal end 31 of the vane 130 and the thickness t3 of the proximal end 32 of the vane 130. The thickness t2 of the distal end portion 31 of the vane 130 and the thickness t3 of the proximal end portion 32 of the vane 130 are the same. A side portion 119 having a thickness t2 is provided between the concave portion 110 of the vane 130 and both end surfaces in the axial direction.

  That is, the concave portion 110 is located on the rear side in the rotation direction of the vane 130 relative to the front surface in the rotation direction of the vane 130 at the distal end portion 31 of the vane 130 and the front surface in the rotation direction of the vane 130 in the base end portion 32 of the vane 130. It is formed so as to be depressed.

  It is preferable that the width (the length in the axial direction) X1 of the concave portion 110 is larger than twice the width (ie, the distance from the vertical surface 114 to the axial end surface) X2 of the side portion 119 (X1> X2). Further, it is preferable that the radial length Y1 of the concave portion 110 is set such that the base end side inner wall surface 113 is located in the slit 22 when the vane 130 projects maximum from the slit 22. Thereby, the area of the concave portion 110 can be sufficiently ensured. Note that the recess 110 may be provided so as to open at one end surface in the axial direction and the other end surface in the axial direction. However, as shown in FIG. By providing the side portion 119 having the thickness t2, the rigidity of the vane 130 can be increased.

  As shown in FIG. 6, the inner wall surface 112 on the distal end side of the concave portion 110 is exposed from the slit 22 at least in expansion regions (suction regions) 42 a and 42 c where the volume of the pump chamber 41 expands. The tip-side inner wall surface 112 exposed from the slit 22 is on the front side in the rotation direction of the vane 130 and faces the rotor 20 side.

  The tip-side inner wall surface 112 is formed such that an angle α between the axis along the projecting direction of the vane 130 and the tip-side inner wall surface 112 is larger than 90 degrees and smaller than 180 degrees. In the present embodiment, the surface of the tip portion 31 of the vane 130 on the front side in the rotation direction is parallel to an axis along the direction in which the vane projects. Therefore, the angle α corresponds to the inner angle of the projection having the vertex at the intersection of the front surface in the rotation direction of the distal end portion 31 of the vane 130 and the inner wall surface 112 on the distal end side.

  The tip side inner wall surface 112 can draw a normal line n perpendicular to the tip side inner wall surface 112 from the tip side inner wall surface 112 toward the rotor 20, and a gap between the tip side inner wall surface 112 and the rotor 20. It is preferable to form so that the normal line n does not cross the vane 130.

  The operation of the vane pump 100 will be described with reference to FIGS. FIG. 6 is a diagram illustrating the flow of hydraulic oil when the vane pump 100 operates.

  When the drive shaft 10 rotates by the power of a drive device (not shown) such as an engine, the rotor 20 rotates in the direction indicated by the arrow A (clockwise in the figure) in FIGS. With the rotation of the rotor 20, the pump chamber 41 located in the expansion regions 42a and 42c expands. Thereby, as shown in FIG. 1, the hydraulic oil in the tank 2 is sucked into the pump chamber 41 through the suction passage 3, the low-pressure chamber 61, the first suction port 81 and the second suction port 82. In addition, as shown in FIG. 2, the pump chamber 41 located in the contraction regions 42b and 42d contracts with the rotation of the rotor 20. Thereby, the hydraulic oil in the pump chamber 41 is discharged to the high-pressure chamber 53 (see FIG. 1) through the discharge port 72. As shown in FIG. 1, the hydraulic oil discharged into the high-pressure chamber 53 is supplied to the external hydraulic device 1 through the discharge passage 4. In the vane pump 100 according to the present embodiment, while the rotor 20 makes one rotation, each pump chamber 41 repeats suction and discharge of the hydraulic oil twice.

  As shown in FIG. 2, a part of the hydraulic oil discharged into the high-pressure chamber 53 is supplied to the back pressure chamber 24, and presses the base end 32 of the vane 130 toward the inner peripheral cam surface 40a. Therefore, the vane 130 is urged in the direction protruding from the slit 22 by the fluid pressure of the back pressure chamber 24 pressing the base end portion 32 and the centrifugal force acting as the rotor 20 rotates. As a result, the distal end 31 of the vane 130 rotates while sliding on the inner peripheral cam surface 40 a of the cam ring 40, so that the operating oil in the pump chamber 41 transfers the distal end 31 of the vane 130 and the inner peripheral cam surface 40 a of the cam ring 40. The liquid is discharged from the discharge port 72 without leaking from between the two.

  Here, in a vane pump (not shown) having a configuration in which the concave portion 110 is not provided in the vane 130, when the rotor 20 is rotated at a high speed, a part of the sucked hydraulic oil is absorbed in the process of sucking the hydraulic oil into the pump chamber 41. May be discharged out of the pump chamber 41 again.

  On the other hand, in the present embodiment, as shown in FIG. 6, a recess 110 is provided on a surface on the front side in the rotation direction of the vane 130. The concave portion 110 is provided with a front end side inner wall surface 112 which is a front side in the rotation direction of the vane 130 and is an inner wall surface facing the rotor 20 side. For this reason, as schematically shown by the arrow B in FIG. 6, by the rotation of the rotor 20, the flow toward the radially inward direction along the circumferential direction can be generated by the inner wall surface 112 on the distal end side of the concave portion 110. As a result, in the process of sucking the hydraulic oil into the pump chamber 41, that is, in the process of moving the pump chamber 41 in the expansion regions (suction regions) 42a and 42c, the operation oil is prevented from being discharged to the outside of the pump chamber 41. can do.

  Further, in the present embodiment, a simple configuration in which the distal end side inner wall surface 112 as an inclined surface is formed in the concave portion 110 of the vane 130, and the hydraulic oil flows out of the pump chamber 41 in the expansion regions (suction regions) 42 a and 42 c. Emission can be suppressed. Thereby, the number of parts and the manufacturing cost can be reduced as compared with the case where the distal end side inner wall surface is formed by incorporating a separate member into the vane 130 or the like.

  The width X1 of the concave portion 110 is larger than twice the width X2 of the side portion 119, and the radial length Y1 of the concave portion 110 is set such that when the vane 130 projects to the maximum from the slit 22, the proximal inner wall surface 113 is formed. Are set to be located in the slit 22. As a result, the area of the recess 110 can be sufficiently ensured, so that the hydraulic oil taken into the recess 110 is pushed out toward the rotor 20 by the tip-side inner wall surface 112, and the flow toward the radially inner side is effectively prevented. Can be generated.

  Further, by providing the concave portion 110 on the surface on the front side in the rotation direction of the vane 130, the sliding friction between the vane 130 and the slit 22 when the vane 130 reciprocates can be reduced. Thereby, the vane 130 can be appropriately pressed against the inner peripheral cam surface 40a. That is, it is possible to effectively prevent the vane 130 from separating from the inner peripheral cam surface 40a. Further, since the sliding resistance of the vane 130 moving in the slit 22 can be reduced, the pressure of the back pressure chamber 24 can be set low.

  According to the above-described embodiment, the following operation and effect can be obtained.

  In the vane pump 100 according to the present embodiment, a recess 110 is provided on a surface on the front side in the rotation direction of the vane 130, and the recess 110 is located on the front side in the rotation direction of the vane 130 and on the tip side facing the rotor 20 side. An inner wall surface 112 is provided. The distal-side inner wall surface 112 is configured to be exposed from the slit 22 at least in expansion regions (suction regions) 42a and 42c where the volume of the pump chamber 41 expands.

  With this configuration, when the rotor 20 rotates at a high speed, the flow toward the radial inside can be generated along the circumferential direction by the inner wall surface 112 on the distal end side of the concave portion 110. Therefore, it is possible to suppress the hydraulic oil from being discharged to the outside of the pump chamber 41 in the process of sucking the hydraulic oil into the pump chamber 41. As a result, when the rotor 20 rotates at a high speed, the amount of hydraulic oil sucked into the pump chamber 41 can be increased, and the volumetric efficiency of the vane pump 100 can be improved.

<Modification of First Embodiment>
In the above-described first embodiment, an example has been described in which the tip-side inner wall surface 112 is a flat inclined surface that is inclined so that the thickness t of the vane 130 increases toward the tip end of the vane 130. The invention is not limited to this. As shown in FIG. 7, the tip-side inner wall surface 212 may be a curved surface that curves so that the thickness t of the vane 230 increases toward the tip side of the vane 230. In this modification, the cross-sectional shape of the concave portion 210 is an arc shape, and the distal inner wall surface 212 and the proximal inner wall surface 213 are connected at the bottom 211.

  Even in such a modification, the flow toward the radial inside can be generated along the circumferential direction by the inner wall surface 212 on the distal end side, so that the same operation and effect as in the first embodiment can be obtained.

<Second embodiment>
A vane pump according to a second embodiment of the present invention will be described with reference to FIGS. 8, 9A, and 9B. FIG. 8 is a front view of the vane 330 when the vane 330 is viewed from the front side in the rotation direction. 9A is a cross-sectional view along the line IXa-IXa of FIG. 8, and FIG. 9B is a cross-sectional view along the line IXb-IXb of FIG. In the following, description will be made focusing on points different from the first embodiment, and in the drawings, the same components as those described in the first embodiment or corresponding components will be denoted by the same reference numerals and description thereof will be omitted. .

  In the second embodiment, the shape of the recess 310 formed in the vane 330 is different from the shape of the recess 110 described in the first embodiment. The details will be described below.

  Two concave portions 310 are formed on the surface of the vane 330 on the front side in the rotation direction. The two concave portions 310 have the same shape and are arranged side by side in the radial direction. The concave portion 310 has a rectangular central concave portion 350 provided at the central portion in the axial direction, a pair of end side concave portions 360 provided from the axial end portion of the central concave portion 350 to the axial end surface of the vane 330, Having.

  The central concave portion 350 has a bottom surface 351 parallel to the sliding surface 330a of the vane 330 that slides on the inner surface of the slit 22, and a front end side extending from the front end of the vane 330 toward the front end of the vane 330 on the bottom surface 351. It has a wall surface 352 and a proximal inner wall surface 353 that rises vertically from the proximal end of the vane 330 on the bottom surface 351.

  The end-side concave portion 360 includes a bottom surface 361 parallel to the sliding surface 330 a of the vane 330, a tip-side inner wall surface 362 extending from the tip end of the vane 330 on the bottom surface 361 toward the tip end of the vane 330, and a bottom surface 361. And a proximal inner wall surface 363 that rises vertically from the proximal end of the vane 330.

  The distal inner wall surface 352 is a flat inclined surface that is inclined so that the thickness t of the vane 330 increases from the bottom surface 351 toward the distal end of the vane 330. Similarly, the distal inner wall surface 362 is a flat inclined surface that is inclined such that the thickness t of the vane 330 increases from the bottom surface 361 toward the distal end of the vane 330. The inner wall surfaces 352 and 362 on the distal end side exposed from the slit 22 are on the front side in the rotation direction of the vane 330 and face the rotor 20 side.

  The distal inner wall surface 352 of the central concave portion 350 forms a first inner wall surface of the concave portion 310 radially opposed to the inner peripheral cam surface 40 a with the distal end portion 331 of the vane 330 interposed therebetween, and the distal end side of the end concave portion 360. The inner wall surface 362 forms a second inner wall surface of the concave portion 310 that radially opposes the cutout portions 40c and 40d with the front end portion 331 of the vane 330 interposed therebetween.

  The tip side inner wall surface 362 is formed so that the distance from the tip end surface of the vane 330 decreases as going from the axial end of the vane 330 to the axial center of the vane 330. Connected to inner wall surface 352. Therefore, when the rotor 20 rotates, the tip-side inner wall surface 362 causes the working oil directed to the notches 40c and 40d to flow toward the notches 40c and 40d in the pump chamber 41, as schematically shown by an arrow C in FIG. It can be guided toward the wall surface 352. That is, the distal-side inner wall surface 362 functions as a guide surface that guides the hydraulic oil toward the notch portions 40c and 40d toward the distal-side inner wall surface 352.

  A part of the hydraulic oil guided to the distal-side inner wall surface 352 flows toward the radially inner side along the circumferential direction by the distal-side inner wall surface 352. Apart from this flow, when a part of the hydraulic oil guided to the inner wall surface 352 on the distal end side is discharged radially outward from the concave portion 310, it collides with the inner peripheral cam surface 40a. For this reason, according to the second embodiment, it is possible to further effectively prevent the hydraulic oil from being discharged out of the pump chamber 41 through the first suction port 81 and the second suction port 82.

  As shown in FIGS. 9A and 9B, the depth h1 of the end-side concave portion 360, that is, the distance from the bottom surface 361 to the front surface in the rotational direction gradually increases from the axial end surface toward the central concave portion 350. Therefore, the depth h2 of the central recess 350, that is, the distance from the bottom surface 351 to the front surface in the rotational direction is larger than the depth h1 of the end recess 360 (h2> h1). By making the depth h <b> 2 of the central recess 350 larger than the depth h <b> 1 of the end-side recess 360, it is possible to increase the flow rate of the hydraulic oil that can stay in the central recess 350. Thereby, the suction amount in the pump chamber 41 can be increased, and the volumetric efficiency can be further improved.

  The central recess 350 is formed parallel to the axial direction, and the end-side recess 360 is formed to intersect the axial direction. For this reason, when the vane 330 reciprocates in the slit 22, it is suppressed that the vane 330 gets caught on the opening edge of the slit 22.

<Modification of Second Embodiment>
In the above-described second embodiment, an example has been described in which the tip-side inner wall surfaces 352 and 362 are flat inclined surfaces that are inclined so that the thickness t of the vane 330 increases as going toward the tip end of the vane 330. However, the present invention is not limited to this. As illustrated in FIGS. 10A and 10B, the inner wall surfaces 452 and 462 on the distal end side may have a curved surface that curves so that the thickness t of the vane 430 increases toward the distal end side of the vane 430. In this modified example, the inner wall surfaces 452, 462 on the distal side and the inner wall surfaces 453, 463 on the proximal side are connected by bottom portions 451, 461.

  Even in such a modified example, since the flow toward the radial inside can be generated along the circumferential direction by the inner wall surfaces 452 and 462 on the distal end side, the same operation and effect as in the first embodiment can be obtained. . Further, the working oil toward the notches 40c and 40d can be guided toward the front-end side inner wall surface 452 in the pump chamber 41 by the front-end side inner wall surface 462. For this reason, as in the second embodiment, even if a part of the hydraulic oil guided to the inner wall surface 452 on the distal end side is discharged from the concave portion 410, the discharged hydraulic oil collides with the inner peripheral cam surface 40a. Will do. Therefore, it is possible to effectively suppress the hydraulic oil from being discharged to the outside of the pump chamber 41 through the first suction port 81 and the second suction port 82.

  The following modifications are also within the scope of the present invention, and the configurations shown in the modifications and the configurations described in the above embodiments are combined, the configurations described in the above different embodiments are combined, It is also possible to combine the configurations described in the modified examples.

<Modification 1>
In the above embodiment, an example in which the vanes 130 and 330 project straight in the radial direction of the rotor 20 has been described, but the present invention is not limited to this. For example, as shown in FIG. 11, the vane 130 may project so as to be inclined forward by an angle β with respect to the radial direction of the rotor 20. In FIG. 11, the vane 130 and the slit 22 according to the first embodiment are indicated by two-dot lines.

  That is, the vane 130 is disposed such that the distal end 31 is located forward of the base end 32 in the rotation direction of the vane 130. The vane 130 protrudes forward from the slit 22 in the rotation direction. For this reason, in the process of sucking the hydraulic oil into the pump chamber 41, it is possible to suppress the discharge of the hydraulic oil to the outside of the pump chamber 41 by using the entire surface on the front side in the rotation direction of the vane 130 including the concave portion 110. Can be.

<Modification 2>
In the first embodiment, an example in which the thickness t2 of the distal end portion 31 of the vane 130 is the same as the thickness t3 of the proximal end portion 32 of the vane 130, but the present invention is not limited to this. For example, as shown in FIG. 12, the thickness t2 of the distal end portion 31 of the vane 130 may be smaller than the thickness t3 of the proximal end portion 32 of the vane 130.

<Modification 3>
In the first embodiment, an example in which one concave portion 110 is provided has been described, but two or more concave portions 110 may be provided. In the second embodiment, an example in which two concave portions 310 are provided has been described. However, three or more concave portions 310 may be provided, or only one concave portion 310 may be provided.

<Modification 4>
In the above embodiment, the example in which the pump cover 60 and the side plate 70 constitute a pair of side members arranged so as to sandwich the rotor 20 and the cam ring 40 has been described, but the present invention is not limited to this. A side plate as a side member attached to the pump cover 60 may be further provided, and the rotor 20 and the cam ring 40 may be sandwiched between the side plate and the side plate 70 attached to the pump body 50.

<Modification 5>
In the above embodiment, the example in which the hydraulic oil is sucked from the low-pressure chamber 61 to the pump chamber 41 inward in the radial direction has been described, but the present invention is not limited to this. A passage communicating between the low-pressure chamber 61 and the pump chamber 41 may be formed in the pump body 50 and the side plate 70 so that hydraulic oil is sucked from the low-pressure chamber 61 into the pump chamber 41 along the axial direction.

<Modification 6>
In the first embodiment, an example is described in which the side portions 119 having a thickness greater than the thickness of the concave portion 110 are provided on both outer sides in the axial direction of the concave portion 110, but the present invention is not limited to this. The recess 110 may be open at both axial end surfaces of the vane 130. Further, in the second embodiment, the example in which the concave portion 310 is provided so as to open at both axial end surfaces of the vane 330 has been described, but the present invention is not limited to this. Side portions having a thickness greater than the thickness of the concave portion 310 may be provided on both axially outer sides of the concave portion 310.

  The configuration, operation, and effect of the embodiment of the present invention configured as described above will be described together.

  The vane pump 100 includes a rotor 20 that is driven to rotate, a plurality of slits 22 that are opened on the outer peripheral surface of the rotor 20, a plurality of vanes 130, 230, 330, and 430 that are slidably housed in the slits 22; A cam ring 40 having an inner peripheral cam surface 40a with which the tip portions 31 and 331 of the plurality of vanes 130, 230, 330 and 430 slidably contact with the rotation of the rotor 20 and a pair of rotors and the cam ring 40 arranged so as to sandwich the cam ring 40. Pump chamber defined by side members (pump cover 60 and side plate 70), rotor 20, cam ring 40, adjacent vanes 130, 230, 330, 430, and a pair of side members (pump cover 60 and side plate 70). 41 and a suction port (first suction port 81) for guiding a working fluid sucked into the pump chamber 41. The second suction port 82), the discharge port 72 for guiding the working fluid discharged from the pump chamber 41, and the concave portions 110, 210, 310, 410 provided on the front surface in the rotation direction of the vanes 130, 230, 330, 430. The recesses 110, 210, 310, and 410 are provided with inner wall surfaces (front end inner wall surfaces 112, 212, 212, 212, 212, 212, 212, 212, 212, 212, 212, 212, 212, 212, 212, 212, and 212) that are forward in the rotation direction of the vanes 130, 230, 330, and 430. 352, 362, 452, 462), and the inner wall surfaces (the inner wall surfaces 112, 212, 352, 362, 452, 462 on the distal end side) are provided with suction regions (expansion regions 42a, 42c) in which at least the volume of the pump chamber 41 is expanded. In ()), it is exposed from the slit 22.

  In this configuration, the inner wall surfaces of the recesses 110, 210, 310, and 410 (the inner wall surfaces 112, 212, 352, 362, 452, and 462) generate a flow that flows radially inward along the circumferential direction. Since the working fluid can be sucked into the pump chamber 41, the working fluid can be prevented from being discharged out of the pump chamber 41. Therefore, the working fluid suction amount into the pump chamber 41 can be increased, and the volumetric efficiency of the vane pump 100 can be improved.

  The vane pump 100 is configured such that the wall thickness (t) of the vanes 130, 330 increases as the inner wall surfaces (the inner wall surfaces 112, 212, 352, 362, 452, 462) move toward the distal ends of the vanes 130, 330. It is an inclined surface that is inclined, or a curved surface that curves so that the thickness t of the vanes 230 and 330 increases toward the tip end side of the vanes 230 and 430.

  In this configuration, the discharge of the working fluid to the outside of the pump chamber 41 can be suppressed with a simple configuration.

  In the vane pump 100, notches 40c and 40d penetrating from the outer peripheral surface to the inner peripheral cam surface 40a of the cam ring 40 constitute a part of the suction port (the first suction port 81 and the second suction port 82). The inner wall surfaces (the inner wall surfaces 112, 212, 352, 362, 452, and 462 on the distal side) radially oppose the inner peripheral cam surface 40a with the distal end portion 331 of the vanes 330 and 430 interposed therebetween. 1 inner wall surfaces (tip-side inner wall surfaces 352, 452) and second inner wall surfaces (tip-side inner wall surfaces 362, 462) radially opposed to the notches 40c, 40d across the tip 331 of the vanes 330, 430. The second inner wall surface (the distal inner wall surfaces 362, 462) guides the working fluid toward the notches 40c, 40d toward the first inner wall surface (the distal inner wall surfaces 352, 452). There is a that guide surface.

  In this configuration, the cutout portions 40c and 40d that constitute a part of the suction ports (the first suction port 81 and the second suction port 82) are located radially opposite to each other with the tip 331 of the vanes 330 and 430 interposed therebetween. Can guide the flow of the working fluid toward the notches 40c and 40d toward the inner peripheral cam surface 40a. For this reason, in the process of sucking the working fluid into the pump chamber 41, it is possible to suppress the working fluid from being discharged from the pump chamber 41 to the notches 40 c and 40 d.

  In the vane pump 100, the vanes 130, 230, 330, and 430 are arranged such that the distal ends 31 and 331 are positioned forward of the vane 130 in the rotation direction of the base end 32.

  In this configuration, the vanes 130, 230, 330, and 430 project forward from the slit 22 in the rotation direction. For this reason, in the process of sucking the working fluid into the pump chamber 41, the working fluid is pumped using the entire surface of the vanes 130, 230, 330, 430 including the recesses 110, 210, 310, 410 on the rotation direction front side. It is possible to suppress discharge to the outside of the chamber 41.

  In the vane pump 100, the thickness t2 of the side portions 119 on both sides in the axial direction of the recesses 110 and 210 in the vanes 130 and 230 is greater than the thickness t1 of the recesses 110 and 210.

  With this configuration, the rigidity of the vanes 130 and 230 can be increased.

  As described above, the embodiment of the present invention has been described. However, the above embodiment is only a part of the application example of the present invention, and the technical scope of the present invention is not limited to the specific configuration of the above embodiment. Absent.

  Reference numeral 20: rotor, 22: slit, 31, 331: distal end, 32: base end, 40: cam ring, 40a: inner peripheral cam surface, 40c, 40d: Notch, 41 ... Pump chamber, 42a, 42c ... Expansion area (suction area), 60 ... Pump cover (side member), 70 ... Side plate (side member), 72 ... Discharge port, 81: first suction port (suction port), 82: second suction port (suction port), 100: vane pump, 110, 210, 310, 410 ... recess, 112, 212 ························································································, Side, 130, 230, 330, 430 ... Down

Claims (5)

A rotationally driven rotor,
A plurality of slits opening on the outer peripheral surface of the rotor,
A plurality of vanes slidably housed in the slit,
A cam ring having an inner peripheral cam surface with which the tips of the plurality of vanes slide in contact with the rotation of the rotor,
A pair of side members arranged to sandwich the rotor and the cam ring,
A pump chamber defined by the rotor, the cam ring, the adjacent vanes, and the pair of side members;
A suction port for guiding a working fluid sucked into the pump chamber;
A discharge port for guiding a working fluid discharged from the pump chamber,
A recess provided on a surface on the rotation direction front side of the vane,
The concave portion is a front side in the rotation direction of the vane, and has an inner wall surface facing the rotor side,
The inner wall surface is exposed from the slit at least in a suction region where the volume of the pump chamber is expanded. The vane pump according to claim 1,
The inner wall surface is inclined such that the thickness of the vane is increased toward the tip end of the vane, or the thickness of the vane is increased toward the tip end of the vane. A vane pump characterized by having a curved surface that curves as follows. In the vane pump according to claim 1 or 2,
In the cam ring, a cutout portion penetrating from the outer peripheral surface to the inner peripheral cam surface is provided so as to constitute a part of the suction port,
The inner wall surface,
A first inner wall surface radially opposed to the inner peripheral cam surface across the tip of the vane;
A second inner wall surface radially opposed to the notch with the tip of the vane interposed therebetween,
The vane pump, wherein the second inner wall surface is a guide surface that guides the working fluid toward the notch toward the first inner wall surface. The vane pump according to any one of claims 1 to 3,
The vane pump according to claim 1, wherein the vane is disposed such that a front end thereof is located forward of a base end in a rotation direction of the vane. The vane pump according to any one of claims 1 to 4,
A vane pump, wherein the thickness of the vane on both sides in the axial direction of the recess is greater than the thickness of the recess.

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