JP2018035778A - Vane pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a suction characteristic of a vane pump.SOLUTION: A vane pump 100 includes a rotor 20, a plurality of vanes 30, a cam ring 40, a pump chamber 41, and a center port 45. The center port 45 has an inner opening 46 opening on an inner cam surface 40a of the cam ring 40, and an outer opening 47 opening on an outer surface 40d of the cam ring 40. A starting end 46a of the inner opening 46 is located more forward in a rotational direction than a first imaginary line I1 connecting a starting end 47a of the outer opening 47 and a rotation center C of the rotor 20.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a vane pump.

  Patent Document 1 discloses a vane pump including a rotor that is rotationally driven, a plurality of vanes that are provided in the rotor so as to be capable of reciprocating in a radial direction, and a cam ring that houses the rotor. As the rotor rotates, the vane is pressed, and the tip of the vane slides on the inner peripheral surface (inner peripheral cam surface) of the cam ring. A pump chamber is formed by the rotor, the cam ring, and the adjacent vanes.

  The vane pump disclosed in Patent Document 1 includes a suction through port that opens to an inner peripheral cam surface in the suction region. The working fluid from the tank is sucked into the pump chamber through the suction through port.

JP 2009-52525 A

  In the vane pump disclosed in Patent Document 1, as the rotational speed of the rotor increases, the working fluid sucked into the pump chamber from the suction through port becomes difficult to reach the front portion of the pump chamber.

  An object of this invention is to improve the suction characteristic of a vane pump.

  The first invention includes a rotor, a plurality of vanes, a cam ring, a pump chamber, and a suction port. The suction port has an inner opening that opens to the inner peripheral cam surface of the cam ring and an outer opening that opens to the outer peripheral surface of the cam ring. The start end of the inner opening is located forward of the first imaginary line connecting the start end of the outer opening and the rotation center of the rotor.

  In the first invention, the starting end of the inner opening is located in front of the first imaginary line in the rotational direction. Therefore, the flow of the working fluid in the suction port is directed in the rotation direction by the wall portion formed from the start end of the outer opening to the start end of the inner opening, and the working fluid reaches the front portion of the pump chamber. Therefore, the working fluid can be sufficiently supplied to the volume of the pump chamber.

  In the second invention, the second imaginary line passing through the end of the inner opening and the end of the outer opening changes from the inner opening to the outer opening with respect to the third imaginary line passing through the starting end of the inner opening and the starting end of the outer opening. The second imaginary line and the third imaginary line are inclined so as to move away from each other.

  In the second invention, the second imaginary line is inclined with respect to the third imaginary line so as to move away from the third imaginary line as it goes from the inner opening toward the outer opening. Therefore, the suction port is formed so that the cross section of the flow path expands from the inner opening toward the outer opening, and reduces the pressure loss of the working fluid that occurs when the working fluid flows into the suction port from the outside of the cam ring. Therefore, the flow rate of the working fluid sucked into the pump chamber through the suction port can be increased, and the suction characteristics of the vane pump can be improved.

  The third invention is characterized in that the end of the inner opening is positioned behind the fourth imaginary line connecting the end of the outer opening and the rotation center of the rotor.

  In 3rd invention, the terminal end of inner side opening is located in the rotation direction back rather than a 4th virtual line. Therefore, the suction port is formed such that the cross section of the flow path is further enlarged from the inner opening toward the outer opening, and the pressure loss of the working fluid that occurs when the working fluid flows into the suction port from the outside of the cam ring is further reduced. . Therefore, the flow rate of the working fluid sucked into the pump chamber through the suction port can be further increased, and the suction characteristics of the vane pump can be improved.

  According to a fourth aspect of the invention, the end of the inner opening is located forward of the fourth imaginary line connecting the end of the outer opening and the rotation center of the rotor.

  In 4th invention, the terminal end of inner side opening is located ahead of a rotation direction rather than a 4th virtual line. Therefore, the wall portion formed from the end of the outer opening to the end of the inner opening does not hinder the flow of the working fluid directed in the rotation direction. The flow of the working fluid is more reliably directed in the rotation direction at the suction port, and the working fluid is distributed to the front portion of the pump chamber. Therefore, the working fluid can be sufficiently supplied to the volume of the pump chamber, and the suction characteristics of the vane pump can be improved.

  The fifth invention is characterized in that the suction port is formed linearly from the outer opening to the inner opening.

  In the fifth invention, the suction port is formed linearly from the outer opening to the inner opening. Therefore, for example, the suction port may be formed by drilling or end milling, and complicated processing is not required for forming the suction port. Therefore, the suction characteristics of the vane pump can be easily improved.

  The sixth invention is characterized in that the suction port is formed to be curved from the outer opening to the inner opening so that the inclination with respect to the radial direction becomes smaller from the outer opening toward the inner opening.

  In the sixth invention, the suction port is formed to be curved from the outer opening to the inner opening. Therefore, the direction of the flow of the working fluid guided from the outer opening to the inner opening changes gradually, and the pressure loss at the suction port is reduced. Therefore, the flow rate of the working fluid sucked into the pump chamber can be increased, and the suction characteristics of the vane pump can be improved.

  According to the present invention, the suction characteristics of the vane pump can be improved.

It is sectional drawing of the vane pump which concerns on 1st Embodiment of this invention. It is a front view of a rotor, a vane, and a cam ring, and shows a state in which the rotor, vane, and cam ring are assembled. It is a front view of the 1st side plate. It is a front view of the 2nd side plate. It is a side view of a cam ring, the 1st side plate, and the 2nd side plate, and shows the state where the 1st side plate and the 2nd side plate were assembled to the cam ring. It is a rear view of a cam ring. It is sectional drawing which follows the VII-VII of FIG. It is sectional drawing for demonstrating the shaping | molding method of the cam ring shown in FIG. It is sectional drawing for demonstrating the shaping | molding method of the cam ring which concerns on the modification of 1st Embodiment. It is sectional drawing of the cam ring in the vane pump which concerns on 2nd Embodiment of this invention, and shows corresponding to FIG. It is sectional drawing for demonstrating the shaping | molding method of the cam ring shown in FIG. It is sectional drawing of the cam ring in the vane pump which concerns on 3rd Embodiment of this invention, and shows corresponding to FIG. It is sectional drawing for demonstrating the shaping | molding method of the cam ring shown in FIG. It is sectional drawing of the cam ring in the vane pump which concerns on 4th Embodiment of this invention, and shows corresponding to FIG.

  Hereinafter, vane pumps 100, 101, 200, 300, and 400 according to embodiments of the present invention will be described with reference to the drawings. The vane pumps 100, 101, 200, 300, and 400 are used as a hydraulic pressure supply source of a hydraulic device 1 (for example, a power steering device or a transmission) mounted on the vehicle. Here, although the vane pumps 100, 101, 200, 300, and 400 in which working oil is used as the working fluid will be described, other fluids such as working water may be used as the working fluid.

<First Embodiment>
First, a vane pump 100 according to a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the vane pump 100 includes a drive shaft 10, a rotor 20 coupled to the drive shaft 10, a plurality of vanes 30 provided on the rotor 20, a cam ring 40 that houses the rotor 20 and the vanes 30, Is provided.

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

  Hereinafter, a direction along the rotation center axis of the rotor 20 is referred to as an “axial direction”, a radial direction around the rotation center axis of the rotor 20 is referred to as a “radial direction”, and the rotor 20 rotates during normal operation of the vane pump 100. This direction is referred to as “rotation direction”.

  The vane pump 100 further includes a first side plate 70 and a second side plate 80 serving as a first side member and a second side member that are disposed with the rotor 20 and the cam ring 40 interposed therebetween in the axial direction. The first side plate 70 and the second side plate 80 have a side surface 70a and a side surface 80a that contact the rotor 20 and the cam ring 40, respectively. A pump chamber 41 is defined by the rotor 20, the cam ring 40, the adjacent vanes 30, the first side plate 70, and the second side plate 80.

  FIG. 2 is a front view of the rotor 20, the vane 30 and the cam ring 40 as viewed from the assembled pump cover 60 side. As shown in FIG. 2, a plurality of slits 22 having openings 21 on the outer peripheral surface are radially formed in the rotor 20 at predetermined intervals. 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. In other words, the protruding portions 23 are formed on the outer periphery of the rotor 20 by the number of the slits 22.

  The vane 30 is slidably inserted into each slit 22. The tip 31 of the vane 30 faces the inner peripheral surface 40 a of the cam ring 40. The base end portion 32 of the vane 30 is located in the slit 22, and the back pressure chamber 24 is formed by the slit 22 and the vane 30.

  When the rotor 20 rotates, centrifugal force is generated in the vane 30. By this centrifugal force, the vane 30 is pressed in a direction protruding from the slit 22. When pressed, the vane 30 protrudes from the slit 22, and the tip 31 of the vane 30 contacts the inner peripheral surface 40 a of the cam ring 40.

  The inner peripheral surface 40a of the cam ring 40 is formed in a substantially oval shape. Hereinafter, the inner peripheral surface 40a of the cam ring 40 is also referred to as “inner peripheral cam surface 40a”.

  Since the inner circumferential cam surface 40 a is formed in a substantially oval shape, the vane 30 reciprocates in the radial direction with respect to the rotor 20 as the rotor 20 rotates. As the vane 30 reciprocates, the pump chamber 41 repeats expansion and contraction.

  In the vane pump 100, the vane 30 reciprocates twice while the rotor 20 makes one rotation, and the pump chamber 41 repeats expansion and contraction twice. That is, the vane pump 100 alternately 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 in the rotation direction.

  Refer to FIG. 1 again. The pump body 50 is formed with a housing recess 51 that houses the rotor 20, the cam ring 40, and the first side plate 70. The first side plate 70 is disposed on the bottom surface 51 a of the housing recess 51.

  An annular groove 52 is formed on the bottom surface 51 a of the housing recess 51. The annular groove 52 and the first side plate 70 form a high-pressure chamber 53 into which hydraulic oil discharged from the pump chamber 41 flows. The high pressure chamber 53 is connected to the hydraulic device 1, and hydraulic oil discharged from the pump chamber 41 is supplied to the hydraulic device 1 through the high pressure chamber 53.

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

  The first side plate 70 is provided with two discharge ports 72 that guide the hydraulic oil discharged from the pump chamber 41 to the high-pressure chamber 53. The discharge port 72 is located in each contraction region 42b, 42d.

  While the pump chamber 41 (see FIG. 2) passes through the contraction regions 42b and 42d, the pump chamber 41 contracts. As the pump chamber 41 contracts, the pressure in the pump chamber 41 increases, and the hydraulic oil in the pump chamber 41 is discharged from the discharge port 72. 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. Thus, since the hydraulic oil is discharged in the contraction regions 42b and 42d, the contraction regions 42b and 42d are also called “discharge regions”.

  The first side plate 70 is formed with two back pressure passages 73 that guide the hydraulic oil from the high pressure chamber 53 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 expansion regions 42a and 42c. Therefore, hydraulic oil is guided from the high pressure chamber 53 to the back pressure chamber 24 that passes through the expansion regions 42a and 42c. The vane 30 passing through the expansion regions 42a and 42c is pressed in a direction protruding from the slit 22 (see FIG. 3) by the pressure in the back pressure chamber 24.

  Thus, in the vane pump 100, the vane 30 is pressed in the direction of 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.

  Refer to FIG. 1 again. The housing recess 51 of the pump body 50 is larger than the cam ring 40. A fluid chamber 54 extending from the outer periphery of the second side plate 80 to the outer periphery of the first side plate 70 is formed between the cam ring 40 and the pump body 50.

  The opening of the housing recess 51 is sealed by the pump cover 60. The pump cover 60 is fastened to the pump body 50 by bolts (not shown). A second side plate 80 is disposed between the pump cover 60 and the cam ring 40.

  FIG. 4 is a front view of the second side plate 80 as viewed from the pump cover 60 side. As shown in FIGS. 1 and 4, the second side plate 80 is formed in an annular shape having a hole 81. The drive shaft 10 is inserted through the hole 81.

  As shown in FIG. 1, a low pressure chamber 61 is formed in the pump cover 60. The low pressure chamber 61 is connected to the tank 2. When the vane pump 100 is operated, the hydraulic oil in the tank 2 is supplied to the low pressure chamber 61. The low pressure chamber 61 communicates with the fluid chamber 54, and the hydraulic oil in the tank 2 is supplied to the fluid chamber 54 through the low pressure chamber 61.

  The cam ring 40 and the second side plate 80 are provided with a side port 82 as a suction port that guides hydraulic oil in the low pressure chamber 61 to the pump chamber 41. Further, the cam ring 40 and the first side plate 70 are provided with a side port 74 as a suction port that guides hydraulic oil in the fluid chamber 54 to the pump chamber 41. The side ports 74 and 82 are located in the extended regions 42a and 42c.

  While the pump chamber 41 passes through the expansion regions 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 side ports 74 and 82. That is, the hydraulic oil is sucked into the pump chamber 41 from the side ports 74 and 82 while the pump chamber 41 passes through the expansion regions 42a and 42c. In this way, since the hydraulic oil is sucked into the pump chamber 41 in the expansion regions 42a and 42c, the expansion regions 42a and 42c are also called “suction regions”.

  FIG. 5 is a side view of the first side plate 70 and the second side plate 80 assembled to the cam ring 40 as seen from the outside in the radial direction. As shown in FIGS. 3 and 5, two depressions 75 are formed on the side surface 70 a of the first side plate 70. The recess 75 opens to the outer peripheral surface 70 b of the first side plate 70.

  FIG. 6 is a rear view of the cam ring 40 as viewed from the first side plate 70 side. As shown in FIGS. 5 and 6, two cutouts 43 are provided on the end surface 40 b of the cam ring 40 in contact with the first side plate 70. The notch 43 is located in the extended regions 42a and 42c, and is formed from the outer peripheral surface 40d of the cam ring 40 to the inner peripheral cam surface 40a.

  In a state where the first side plate 70 is assembled to the cam ring 40, the recess 75 of the first side plate 70 faces the notch 43 of the cam ring 40. The hydraulic oil in the fluid chamber 54 (see FIG. 1) is guided to the pump chamber 41 through a port formed by the recess 75 and the notch 43. That is, in the vane pump 100, the side port 74 is formed by the recess 75 of the first side plate 70 and the notch 43 of the cam ring 40.

  As shown in FIGS. 4 and 5, two recessed portions 83 are provided on the outer peripheral surface 80 b of the second side plate 80. The recessed portion 83 is formed from the side surface 80a of the second side plate 80 to the side surface 80c of the second side plate 80 opposite to the side surface 80a.

  As shown in FIGS. 2 and 5, two notches 44 are provided on the end surface 40 c of the cam ring 40 that contacts the second side plate 80. The notch 44 is located in the extended regions 42a and 42c, and is formed from the outer peripheral surface 40d of the cam ring 40 to the inner peripheral cam surface 40a.

  In a state where the second side plate 80 is assembled to the cam ring 40, the recessed portion 83 of the second side plate 80 faces the notch 44 of the cam ring 40. The hydraulic oil in the low pressure chamber 61 (see FIG. 1) is guided to the pump chamber 41 through a port formed by the recess 83 and the notch 44. Thus, in the vane pump 100, the side port 82 is formed by the recessed portion 83 of the second side plate 80 and the notch 44 of the cam ring 40.

  7 is a cross-sectional view taken along the line VII-VII in FIG. As shown in FIGS. 1, 5, and 7, the cam ring 40 is provided with a center port 45 as a suction port that guides hydraulic oil in the fluid chamber 54 to the pump chamber 41. The center port 45 penetrates between the outer peripheral surface 40d of the cam ring 40 and the inner peripheral cam surface 40a. That is, the center port 45 has an inner opening 46 that opens to the inner peripheral cam surface 40a and an outer opening 47 that opens to the outer peripheral surface 40d.

  The inner opening 46 of the center port 45 is disposed at the center of the cam ring 40 in the axial direction. The hydraulic oil sucked through the center port 45 flows into the central portion of the pump chamber 41 in the axial direction. Therefore, the hydraulic oil can be distributed to the central portion of the pump chamber 41, and the suction characteristics of the vane pump 100 can be improved.

  As shown in FIG. 7, the start end 46 a of the inner opening 46 is located forward of the first imaginary line I <b> 1 connecting the start end 47 a of the outer opening 47 and the rotation center C of the rotor 20 in the rotation direction. The second imaginary line I2 passing through the end 46b of the inner opening 46 and the end 47b of the outer opening 47 is inclined with respect to the third imaginary line I3 passing through the start end 46a of the inner opening 46 and the start end 47a of the outer opening 47. Yes. Specifically, the second virtual line I2 and the third virtual line I3 are inclined so that the second virtual line I2 and the third virtual line I3 are separated from the inner opening 46 toward the outer opening 47.

  The “starting end” of the inner opening 46 means an end portion 46 a of the inner opening 46 positioned rearward in the rotation direction. Further, the “end” of the inner opening 46 means an end portion 46 b of the inner opening 46 positioned forward in the rotation direction. That is, when the vane pump 100 is operated, the pump chamber 41 moved into the expansion regions 42 a and 42 c reaches the start end 46 a of the inner opening 46, so that the pump chamber 41 communicates with the center port 45. When the pump chamber 41 passes through the end 46 b of the inner opening 46, the communication between the pump chamber 41 and the center port 45 is blocked.

  The “start end” of the outer opening 47 means an end portion 47 a of the outer opening 47 that is located rearward in the rotation direction. The “terminal end” of the outer opening 47 means an end portion 47 b of the outer opening 47 positioned forward in the rotation direction.

  In the vane pump 100, the start end 46a of the inner opening 46 is located forward of the first imaginary line I1 in the rotational direction. Therefore, the wall 45a formed from the start end 47a of the outer opening 47 to the start end 46a of the inner opening 46 is separated from the first imaginary line I1 toward the start end 46a of the inner opening 46 from the start end 47a of the outer opening 47. Formed.

  The wall 45a having such a shape directs the flow of hydraulic oil in the center port 45 in the rotation direction. Therefore, the hydraulic oil reaches the front part of the pump chamber 41.

  Temporarily, in the vane pump in which the wall part 45a extends along the radial direction, the wall part 45a directs the flow of hydraulic oil in the center port 45 in the radial direction. Since the vane 30 rotates together with the rotor 20, the hydraulic oil directed in the radial direction may stay in the rear part of the pump chamber 41 without reaching the front part of the pump chamber 41.

  When the hydraulic oil stays behind the pump chamber 41, the hydraulic oil supplied to the pump chamber 41 is insufficient with respect to the volume of the pump chamber 41. As a result, the amount of hydraulic oil discharged from the discharge port 72 is reduced, and the suction characteristics of the vane pump are deteriorated.

  The stagnation of hydraulic oil in the rear portion of the pump chamber 41 is likely to occur when the rotor 20 rotates at a high speed, specifically, when the speed of the tip 31 of the vane 30 rotates at approximately 14 m / s or more. Therefore, in the vane pump in which the wall part 45a extends along the radial direction, the suction characteristics in the high rotation region are deteriorated.

  In the vane pump 100 according to the present embodiment, the wall 45a is formed so as to move away from the first imaginary line I1 toward the start end 46a of the inner opening 46 from the start end 47a of the outer opening 47. Therefore, the flow of hydraulic oil in the center port 45 is directed in the rotational direction, and the hydraulic oil reaches the front portion of the pump chamber 41. Therefore, the hydraulic oil can be sufficiently supplied to the volume of the pump chamber 41, and the suction characteristics of the vane pump 100, particularly, the suction characteristics in a high rotation region can be improved.

  In the vane pump 100, the second virtual line I2 is inclined with respect to the third virtual line I3. Therefore, the center port 45 is formed so that the cross section of the flow path expands from the inner opening 46 toward the outer opening 47.

  The center port 45 having such a shape reduces pressure loss of the hydraulic oil that occurs when the hydraulic oil flows into the center port 45 from the outside of the cam ring 40. Therefore, the flow rate of the working oil sucked into the pump chamber 41 through the center port 45 can be increased, and the suction characteristics of the vane pump 100 can be further improved.

  Further, in the vane pump 100, the end 46 b of the inner opening 46 is located behind the fourth imaginary line I 4 that connects the end 47 b of the outer opening 47 and the rotation center C of the rotor 20. Therefore, the center port 45 is formed such that the cross section of the flow path is further enlarged from the inner opening 46 toward the outer opening 47. Therefore, the flow rate of the hydraulic oil sucked into the pump chamber 41 through the center port 45 can be further increased, and the suction characteristics of the vane pump 100 can be improved.

  The center port 45 is formed linearly from the outer opening 47 to the inner opening 46. Specifically, the wall portion 45 a of the center port 45 is formed linearly from the start end 47 a of the outer opening 47 to the start end 46 a of the inner opening 46. Further, the wall portion 45 b of the center port 45 opposite to the wall portion 45 b is formed linearly from the terminal end 47 b of the outer opening 47 to the terminal end 46 b of the inner opening 46.

  The straight wall portions 45a and 45b are formed by, for example, drilling. Drilling is a simple processing method and does not require complicated processing to form the center port 45. Therefore, the center port 45 can be easily formed, and the suction characteristics of the vane pump 100 can be easily improved. The center port 45 may be formed by end milling.

  Next, the operation of the vane pump 100 will be described with reference to FIGS.

  When the power of the engine or the electric motor (not shown) is transmitted to the drive shaft 10, the rotor 20 rotates as the drive shaft 10 rotates. As the rotor 20 rotates, the vane 30 reciprocates with respect to the rotor 20, and the pump chamber 41 repeats expansion and contraction.

  The hydraulic oil in the tank 2 is guided through the side port 74, the side port 82, and the center port 45 to the pump chamber 41 that passes through the expansion regions 42a and 42c.

  The wall portion 45a of the center port 45 is inclined with respect to the radial direction and directs the flow of hydraulic oil guided from the outer opening 47 to the inner opening 46 in the rotation direction. Therefore, the hydraulic oil guided to the pump chamber 41 through the center port 45 reaches the front portion of the pump chamber 41. Accordingly, the hydraulic oil can be sufficiently supplied to the volume of the pump chamber 41.

  Further, the center port 45 is formed such that the cross section of the flow path is further enlarged from the inner opening 46 toward the outer opening 47. Therefore, when hydraulic fluid flows from the fluid chamber 54 into the center port 45, pressure loss of the hydraulic fluid is unlikely to occur. Therefore, the flow rate of the hydraulic oil sucked into the pump chamber 41 through the center port 45 can be increased.

  The hydraulic oil in the pump chamber 41 that passes through the contraction regions 42 b and 42 d is discharged from the discharge port 72. Since the hydraulic oil is sufficiently supplied to the pump chamber 41, the flow rate of the hydraulic oil discharged from the discharge port 72 increases. Therefore, the suction characteristics of the vane pump 100 can be improved.

  Next, a method for manufacturing the vane pump 100 will be described. Here, the cam ring 40 forming method will be described in detail with reference to FIG. FIG. 8 is a cross-sectional view for explaining a method for forming the cam ring 40.

  First, the base material of the cam ring 40 is formed by mold forming. In the base material of the cam ring 40, notches 43 and 44 (see FIGS. 2, 5, and 6) are formed, but the center port 45 is not formed.

  Next, the drill 3 is pressed around the outer peripheral surface 40d of the cam ring 40 while rotating around the central axis 3a, and the circular hole 3b is formed in the cam ring 40 by cutting. At this time, the inner opening of the circular hole 3b is formed in the extended region 42a of the inner peripheral cam surface 40a.

  Next, the drill 3 is rotated relative to the cam ring 40 around the point P1 inside the cam ring 40 and in the expansion region 42a while rotating the drill 3 around the central axis 3a. As a result, the center port 45 shown in FIG. 7 is formed in the extended region 42a by cutting. At this time, the wall portion 45 a of the center port 45 is formed in a straight line from the start end 47 a of the outer opening 47 to the start end 46 a of the inner opening 46, and the wall portion 45 b of the center port 45 is formed from the end 47 b of the outer opening 47 to the inner opening. It is formed in a straight line over the end 46b of 46.

  Next, the center port 45 of the expansion region 42c is formed using the drill 3 in the same manner as the center port 45 of the expansion region 42a. The cam ring 40 is completed through the above steps.

  FIG. 9 is a cross-sectional view for explaining a method of forming the cam ring 140 in the vane pump 101 according to the modification of the first embodiment. In forming the center port 145 of the cam ring 140, the drill 3 is rotated relative to the cam ring 140 around a point P2 that is farther from the rotation center C than the point P1 (see FIG. 8).

  In this case, the outer opening 147 can be made larger than the outer opening 47 (see FIG. 7) while the size of the inner opening 146 is the same as the size of the inner opening 46 (see FIG. 7). Therefore, the flow rate of the hydraulic oil sucked into the pump chamber 41 (see FIG. 7) through the center port 145 can be further increased.

Second Embodiment
Next, with reference to FIG.10 and FIG.11, the vane pump 200 which concerns on 2nd Embodiment of this invention is demonstrated. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 10 is a cross-sectional view of the cam ring 240 included in the vane pump 200 and corresponds to FIG.

  Similar to the cam ring 40 (see FIG. 7), the start end 246 a of the inner opening 246 is positioned forward of the first imaginary line I 201 connecting the start end 247 a of the outer opening 247 and the rotation center C of the rotor 20. Therefore, the flow of hydraulic oil in the center port 245 is directed in the rotational direction by the wall portion 245 a, and the hydraulic oil spreads to the front portion of the pump chamber 41. Therefore, the suction characteristics of the vane pump 200 can be improved.

  In the cam ring 240, the center port 245 is a circular hole. That is, the second imaginary line I202 that passes through the end 246b of the inner opening 246 and the end 247b of the outer opening 247 is parallel to the third imaginary line I203 that passes through the starting end 246a of the inner opening 246 and the starting end 247a of the outer opening 247. . The wall portion 245 a of the center port 245 is formed in a straight line from the start end 247 a of the outer opening 247 to the start end 246 a of the inner opening 246. The wall portion 245b of the center port 245 is formed in a straight line from the end 247b of the outer opening 247 to the end 246b of the inner opening 246.

  The center port 245 formed of a circular hole is formed by drilling. Drilling is a simple processing method and does not require complicated processing to form the center port 245. Therefore, the center port 245 can be easily formed, and the suction characteristics of the vane pump 200 can be easily improved.

  Since the operation of the vane pump 200 is substantially the same as the operation of the vane pump 100, the description thereof is omitted here.

  Next, a method for manufacturing the vane pump 200 will be described. Here, the cam ring 240 forming method will be described in detail with reference to FIG. FIG. 11 is a cross-sectional view for explaining a method for forming the cam ring 240.

  First, similarly to the cam ring 40 (see FIG. 8), the base material of the cam ring 240 is formed by molding.

  Next, the drill 3 is pressed around the outer peripheral surface 240d of the cam ring 240 while rotating around the central axis 3a, and the circular hole 3b is formed in the cam ring 240 by cutting. At this time, the inner opening of the circular hole 3b is formed in the extended region 42a in the inner peripheral cam surface 240a. The orientation of the drill 3 is determined so that the center axis 3a of the drill 3 is deviated from the rotation center C.

  Next, the drill 3 is extracted from the circular hole 3b. As a result, the center port 245 shown in FIG. 10 is formed in the extended region 42a. That is, the circular hole 3 b is used as the center port 245.

  Next, the center port 245 (see FIG. 10) of the expansion region 42c is formed using the drill 3 in the same manner as the center port 245 of the expansion region 42a. The cam ring 240 is completed through the above steps.

  Thus, in the cam ring 240, it is not necessary to rotate the drill 3 relative to the base material of the cam ring 240. Therefore, the center port 245 can be easily formed, and the suction characteristics of the vane pump 200 can be easily improved.

<Third Embodiment>
Next, with reference to FIG.12 and FIG.13, the vane pump 300 which concerns on 3rd Embodiment of this invention is demonstrated. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 12 is a cross-sectional view of the cam ring 340 included in the vane pump 300, corresponding to FIG.

  Similar to the cam ring 40 (see FIG. 7), the starting end 346 a of the inner opening 346 is positioned forward of the first imaginary line I 301 that connects the starting end 347 a of the outer opening 347 and the rotation center C of the rotor 20. Therefore, the flow of hydraulic oil in the center port 345 is directed in the rotational direction by the wall portion 345 a, and the hydraulic oil spreads to the front portion of the pump chamber 41. Therefore, the suction characteristics of the vane pump 300 can be improved.

  The second imaginary line I302 passing through the end 346b of the inner opening 346 and the end 347b of the outer opening 347 is inclined with respect to the third imaginary line I303 passing through the start end 346a of the inner opening 346 and the start end 347a of the outer opening 347. Specifically, the second virtual line I302 and the third virtual line I303 are inclined so that the second virtual line I302 and the third virtual line I303 are separated from the inner opening 346 toward the outer opening 347. Therefore, the center port 345 is formed so that the flow path cross section expands from the inner opening 346 toward the outer opening 347. Therefore, similarly to the vane pump 100, the flow rate of the working oil sucked into the pump chamber 41 through the center port 345 can be increased, and the suction characteristics of the vane pump 300 can be improved.

  In the vane pump 300, the end 346 b of the inner opening 346 is positioned forward of the fourth imaginary line I 304 connecting the end 347 b of the outer opening 347 and the rotation center C of the rotor 20 in the rotation direction. Therefore, the wall portion 345b is formed so as to move away from the fourth virtual line I304 as it goes from the end 347b of the outer opening 347 to the end 346b of the inner opening 346.

  The wall portion 345b having such a shape does not hinder the flow of hydraulic oil directed in the rotation direction by the wall portion 345a. Therefore, the flow of hydraulic oil is more reliably directed in the rotational direction at the center port 345, and the hydraulic oil reaches the front portion of the pump chamber 41. Therefore, the hydraulic oil can be sufficiently supplied to the volume of the pump chamber 41, and the suction characteristics of the vane pump 300 can be improved.

  The center port 345 is formed in a straight line from the outer opening 347 to the inner opening 346 in the same manner as the center port 45 (see FIG. 7). Therefore, the center port 345 can be easily formed, and the suction characteristics of the vane pump 300 can be easily improved.

  Since the operation of the vane pump 300 is substantially the same as the operation of the vane pump 100, the description thereof is omitted here.

  Next, a method for manufacturing the vane pump 300 will be described. Here, the cam ring 340 forming method will be described in detail with reference to FIG. FIG. 13 is a cross-sectional view for explaining a method for forming the cam ring 340.

  First, as with the cam ring 40 (see FIG. 8), the base material of the cam ring 340 is formed by mold forming.

  Next, the drill 3 is pressed around the outer peripheral surface 340d of the cam ring 340 while rotating around the central axis 3a, and the circular hole 3b is formed in the cam ring 340 by cutting. At this time, the inner opening of the circular hole 3b is formed in the extended region 42a of the inner peripheral cam surface 340a.

  Next, the drill 3 is rotated relative to the cam ring 340 around the point P3 inside the cam ring 340 and in the contraction region 42b while rotating the drill 3 around the central axis 3a. As a result, the center port 345 shown in FIG. 12 is formed in the extended region 42a by cutting. At this time, the wall 345a of the center port 345 is formed in a straight line, and the wall 345b of the center port 345 is formed in a straight line.

  Next, the center port 345 of the expansion region 42c is formed using the drill 3 in the same manner as the center port 345 of the expansion region 42a. The cam ring 340 is completed through the above steps.

  The straight wall portions 45a and 45b are formed by drilling. Drilling is a simple processing method and does not require complicated processing to form the center port 345. Therefore, the center port 345 can be easily formed, and the suction characteristics of the vane pump 300 can be easily improved. The center port 45 may be formed by end milling.

<Fourth embodiment>
Next, with reference to FIG. 14, the vane pump 400 which concerns on 4th Embodiment of this invention is demonstrated. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 14 is a cross-sectional view of the cam ring 440 included in the vane pump 400, corresponding to FIG.

  Similar to the cam ring 40 (see FIG. 7), the start end 446 a of the inner opening 446 is positioned forward of the first imaginary line I 401 that connects the start end 447 a of the outer opening 447 and the rotation center C of the rotor 20. Therefore, the flow of hydraulic oil in the center port 445 is directed in the rotation direction by the wall portion 445 a, and the hydraulic oil spreads to the front portion of the pump chamber 41. Therefore, the suction characteristics of the vane pump 400 can be improved.

  The second imaginary line I402 passing through the end 446b of the inner opening 446 and the end 447b of the outer opening 447 is inclined with respect to the third imaginary line I403 passing through the starting end 446a of the inner opening 446 and the starting end 447a of the outer opening 447. Specifically, the second virtual line I402 and the third virtual line I403 are inclined so that the second virtual line I402 and the third virtual line I403 are separated from the inner opening 446 toward the outer opening 447. Therefore, the center port 445 is formed so that the flow path cross section expands from the inner opening 446 toward the outer opening 447. Therefore, similarly to the vane pump 100, the flow rate of the working oil sucked into the pump chamber 41 through the center port 445 can be increased, and the suction characteristics of the vane pump 400 can be improved.

  Similarly to the cam ring 340 (see FIG. 12), the end 446 b of the inner opening 446 is positioned forward of the fourth imaginary line I 404 connecting the end 447 b of the outer opening 447 and the rotation center C of the rotor 20 in the rotation direction. To do. Therefore, the wall portion 445b does not hinder the flow of hydraulic oil directed in the rotation direction by the wall portion 445a. In the center port 445, the flow of hydraulic oil is more reliably directed in the rotational direction, and the hydraulic oil reaches the front portion of the pump chamber 41. Therefore, the suction characteristics of the vane pump 400 can be improved.

  The center port 445 is formed to be curved from the outer opening 447 to the inner opening 446 so that the inclination with respect to the radial direction becomes smaller toward the inner opening 446 from the outer opening 447. Specifically, the wall portion 445 a of the center port 445 is formed to be curved in a convex shape from the start end 447 a of the outer opening 447 to the start end 446 a of the inner opening 446. The wall portion 445b of the center port 445 is formed to be concavely curved from the end 447b of the outer opening 447 to the end 446b of the inner opening 446.

  The curved wall portions 445a and 445b gently change the direction of the flow of hydraulic fluid guided from the outer opening 447 to the inner opening 446. Therefore, the pressure loss at the center port 445 is reduced. Therefore, the flow rate of the working oil sucked into the pump chamber 41 can be increased, and the suction characteristics of the vane pump 400 can be improved.

  Since the operation of the vane pump 400 is substantially the same as the operation of the vane pump 100, the description thereof is omitted here.

  The center port 445 of the cam ring 440 is formed, for example, by molding.

  Hereinafter, the configuration, operation, and effect of the embodiment of the present invention will be described together.

  In the present embodiment, the vane pumps 100, 101, 200, 300, and 400 include the rotor 20 that is rotationally driven, the plurality of vanes 30 that are provided in the rotor 20 so as to reciprocate in the radial direction, and the rotation of the rotor 20. Cam rings 40, 140, 240, 340, 440 having inner peripheral cam surfaces 40a, 240a, 340a with which the tip portions 31 of the plurality of vanes 30 are in sliding contact, the rotor 20, the cam rings 40, 140, 240, 340, 440, and the adjacent A pump chamber 41 defined by the mating vanes 30; and center ports 45, 145, 245, 345, 445 formed in the cam rings 40, 140, 240, 340, 440 for guiding hydraulic oil to the pump chamber 41; The center ports 45, 145, 245, 345, 445 have inner cam surfaces 40 a, 240 a, 340. Inner openings 46, 146, 246, 346, 446 opening to the outer periphery, outer openings 47, 147, 247, 347, 447 opening to the outer peripheral surfaces 40d, 240d, 340d of the cam rings 40, 140, 240, 340, 440, The start ends 46a, 246a, 346a, 446a of the inner openings 46, 146, 246, 346, 446 and the start ends 47a, 247a, 347a, 447a of the outer openings 47, 147, 247, 347, 447 and the rotor 20 It is located forward of the first virtual lines I1, I201, I301, I401 connecting the rotation center C in the rotational direction.

  In this configuration, the start ends 46a, 246a, 346a, and 446a of the inner openings 46, 146, 246, 346, and 446 are located in front of the first virtual lines I1, I201, I301, and I401 in the rotational direction. Therefore, the flow of the hydraulic oil in the center ports 45, 145, 245, 345, 445 flows from the start ends 47 a, 247 a, 347 a, 447 of the outer openings 47, 147, 247, 347, 447 a to the inner openings 46, 146, 246, 346. , 446 is directed in the rotational direction by wall portions 45 a, 245 a, 345 a, 445 a formed over the start ends 46 a, 246 a, 346 a, 446 a, and the working oil is distributed to the front portion of the pump chamber 41. Therefore, the hydraulic oil can be sufficiently supplied to the volume of the pump chamber 41, and the suction characteristics of the vane pumps 100, 101, 200, 300, 400 can be improved.

  In the present embodiment, the vane pumps 100, 101, 300, and 400 include end points 46 b, 346 b, 446 b of the inner openings 46, 146, 346, 446 and end points 47 b, 347 b, 447 b of the outer openings 47, 147, 347, 447. Second imaginary lines I2, I302, and I402 passing through the first openings 46a, 346a, and 446a of the inner openings 46, 146, 346, and 446 and starting ends 47a, 347a, and 447a of the outer openings 47, 147, 347, and 447, respectively. With respect to the third virtual lines I3, I303, and I403, the second virtual lines I2, I302, and I402 and the third virtual line I3 are directed toward the outer openings 47, 147, 347, and 447 from the inner openings 46, 146, 346, and 446. , I303 and I403 are inclined so as to be separated from each other.

  In this configuration, the second virtual lines I2, I302, and I402 are separated from the third virtual lines I3, I303, and I403 toward the outer openings 47, 147, 347, and 447 from the inner openings 46, 146, 346, and 446. It inclines with respect to the 3rd virtual lines I3, I303, and I403. Therefore, the center ports 45, 145, 345, 445 are formed such that the flow path cross section expands from the inner openings 46, 146, 346, 446 toward the outer openings 47, 147, 347, 447, and hydraulic oil is cam ring 40, 140, 340, 440 reduces the hydraulic oil pressure loss that occurs when it flows into the center ports 45, 145, 345, 445 from the outside. Therefore, the flow rate of the working oil sucked into the pump chamber 41 through the center ports 45, 145, 345, and 445 can be increased, and the suction characteristics of the vane pumps 100, 101, 300, and 400 can be improved.

  Further, in the present embodiment, the vane pumps 100 and 101 rotate at the end 46b of the inner openings 46 and 146 more than the fourth imaginary line I4 connecting the end 47b of the outer openings 47 and 147 and the rotation center C of the rotor 20. Located behind the direction.

  In this configuration, the terminal ends 46b of the inner openings 46, 146 are located behind the fourth virtual line I4 in the rotational direction. Therefore, the center ports 45 and 145 are formed so that the cross-section of the flow path is further enlarged from the inner openings 46 and 146 toward the outer openings 47 and 147, and the hydraulic oil flows from the outer sides of the cam rings 40 and 140 to the center ports 45 and 145. The pressure loss of hydraulic oil that occurs when it flows into the tank is further reduced. Therefore, the flow rate of the working oil sucked into the pump chamber 41 through the center ports 45 and 145 can be further increased, and the suction characteristics of the vane pumps 100 and 101 can be improved.

  In the present embodiment, the vane pumps 300 and 400 include the fourth imaginary line I304 in which the terminal ends 346b and 446b of the inner openings 346 and 446 connect the terminal ends 347b and 447b of the outer openings 347 and 447 and the rotation center C of the rotor 20. , I404 is located forward of the rotational direction.

  In this configuration, the terminal ends 346b and 446b of the inner openings 346 and 446 are positioned in front of the fourth virtual lines I304 and I404 in the rotational direction. Therefore, the wall portions 345b and 445b formed from the terminal ends 347b and 447b of the outer openings 347 and 447 to the terminal ends 346b and 446b of the inner openings 346 and 446 do not hinder the flow of hydraulic oil directed in the rotational direction. In the center ports 345 and 445, the flow of hydraulic oil is more reliably directed in the rotational direction, and the hydraulic oil reaches the front portion of the pump chamber 41. Accordingly, the hydraulic oil can be sufficiently supplied to the volume of the pump chamber 41, and the suction characteristics of the vane pumps 300 and 400 can be improved.

  In the present embodiment, the vane pumps 100, 101, 200, and 300 have center ports 45, 145, 245, and 345 extending from the outer openings 47, 147, 247, and 347 to the inner openings 46, 146, 246, and 346, respectively. It is formed in a straight line.

  In this configuration, the center ports 45, 145, 245, 345 are formed linearly from the outer openings 47, 147, 247, 347 to the inner openings 46, 146, 246, 346. Therefore, for example, the center ports 45, 145, 245, and 345 may be formed by drilling, and complicated processing is not required for forming the center ports 45, 145, 245, and 345. Therefore, the suction characteristics of the vane pumps 100, 101, 200, and 300 can be easily improved.

  Further, in the present embodiment, the vane pump 400 is formed so that the center port 445 is curved from the outer opening 447 to the inner opening 446 so that the inclination with respect to the radial direction becomes smaller toward the inner opening 446 from the outer opening 447. The

  In this configuration, the center port 445 is formed to be curved from the outer opening 447 to the inner opening 446. For this reason, the direction of the flow of the hydraulic oil guided from the outer opening 447 to the inner opening 446 changes gently, and the pressure loss in the center port 445 decreases. Therefore, the flow rate of the working oil sucked into the pump chamber 41 can be increased, and the suction characteristics of the vane pump 400 can be improved.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  (1) In the above embodiment, the example in which the present invention is applied to the center ports 45, 145, 245, 345, 445 has been described. However, the present invention can also be applied to the side ports 74 and 82.

  (2) In the above embodiment, the side port 74 is formed by the recess 75 of the first side plate 70 and the notch 43 of the cam ring 40. In the present invention, the recess 75 is not formed in the first side plate 70, and the side port 74 is formed by the planar side surface 70 a of the first side plate 70 and the notch 43 of the cam ring 40. Good.

  (3) In the above embodiment, the side port 82 is formed by the recessed portion 83 of the second side plate 80 and the notch 44 of the cam ring 40. In the present invention, the notch 44 is not formed in the second side plate 80, and the side port 82 is formed by the planar side surface 80 a of the second side plate 80 and the notch 44 of the cam ring 40. Good.

  (4) In the above embodiment, the center ports 45, 145, 245, 345 are formed linearly, and the center port 445 is formed curved. The center ports 45, 145, 245, 345, 445 may be formed by bending. Specifically, the wall portions 45a, 145a, 246a, 345a, 445a and the wall portions 45b, 145b, 246b, 345b, 445b may be bent.

  20 ... rotor, 30 ... vane, 31 ... tip, 40, 140, 240, 340, 440 ... cam ring, 40a, 240a, 340a ... inner peripheral cam surface, 40d, 240d, 340d ... outer peripheral surface, 41 ... pump chamber, 45, 145, 245, 345, 445 ... center port (suction port), 46, 146, 246, 346, 446 ... inner opening, 46a, 246a, 346a, 446a ... start end, 46b, 246b, 346b, 446b ... end, 47, 147, 247, 347, 447 ... outside opening, 47a, 247a, 347a, 447a ... start end, 47b , 247b, 347b, 447b ... terminal, 100, 101, 200, 300, 400 ... vane pump, I1, I201, I301, I 01 ... first virtual line, I2, I202, I302, I402 ... second virtual line, I3, I203, I303, I403 ... third virtual line, I4, I204, I304, I404 ... first 4 virtual lines

Claims (6)

A rotor that is driven to rotate;
A plurality of vanes provided in the rotor so as to freely reciprocate in a radial direction;
A cam ring having an inner circumferential cam surface with which the tip portions of the plurality of vanes slide in contact with the rotation of the rotor;
A pump chamber defined by the rotor, the cam ring, and the adjacent vanes;
A suction port formed in the cam ring and guiding the working fluid to the pump chamber,
The suction port has an inner opening that opens to the inner circumferential cam surface, and an outer opening that opens to the outer circumferential surface of the cam ring,
The vane pump characterized in that the start end of the inner opening is located in front of the first imaginary line connecting the start end of the outer opening and the rotation center of the rotor.   A second imaginary line passing through the end of the inner opening and the end of the outer opening is from the inner opening to the outer opening with respect to a third imaginary line passing through the starting end of the inner opening and the starting end of the outer opening. 2. The vane pump according to claim 1, wherein the vane pump is inclined so that the second imaginary line and the third imaginary line are separated from each other.   3. The vane pump according to claim 1, wherein the terminal end of the inner opening is located behind the fourth imaginary line connecting the terminal end of the outer opening and the rotation center of the rotor.   3. The vane pump according to claim 1, wherein a terminal end of the inner opening is positioned forward of a fourth imaginary line that connects a terminal end of the outer opening and the rotation center of the rotor.   5. The vane pump according to claim 1, wherein the suction port is formed linearly from the outer opening to the inner opening.   5. The suction port is formed to be curved from the outer opening to the inner opening so that an inclination with respect to a radial direction becomes smaller toward the inner opening from the outer opening. A vane pump according to any one of the above.

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