JP6355389B2 - Vane pump - Google Patents

Description

  The present invention relates to a vane pump in which a plurality of vanes provided so as to be slidable in the radial direction of a rotor are slidably contacted with a cam surface and fluid is sucked from a suction port and discharged from the discharge port.

  In this type of vane pump, a vane is slidably inserted in a plurality of vane storage slit grooves formed in a rotor in a radial direction, and the tip of the vane is slidably contacted with a cam surface by the rotational drive of the rotor. Fluid is sucked into a pump chamber defined by a cam surface from a suction port that opens to the suction region, and fluid sucked into the pump chamber is discharged from a discharge port that opens to the discharge region. And on the side wall where the side surface of the rotor is slidably contacted, there is a suction-side arc-shaped groove portion that is located in the suction region and communicates with the suction side, and a discharge-side arc-shaped groove portion that is located in the discharge region and communicates with the discharge side. When the base end of the vane storage slit groove is positioned in the suction area by the rotation of the rotor, suction pressure is introduced from the arc-shaped groove on the suction side and the base end of the vane storage slit groove Is positioned in the discharge region, the discharge pressure is introduced from the arc-shaped groove on the discharge side, and the vane is pressed against the cam surface to suppress a decrease in the sealing performance of the pump chamber.

JP-A-7-259754

  However, in such a conventional vane pump, the arc-shaped groove on the discharge side for introducing discharge pressure to the base end of the slit groove for vane storage extends to the suction region beyond the end of the suction port in the rotation direction of the rotor. Therefore, there is a problem that the vane is excessively pressed against the cam surface in the suction region, and the rotational driving force for rotating the rotor is increased.

  The subject of this invention is providing the vane pump which can reduce the rotational drive force which rotates a rotor.

In order to achieve this problem, the present invention has taken the following measures. That is,
A rotor provided rotatably in the pump body, a plurality of vane storage slit grooves formed in the rotor and slidably inserted in the radial direction, and opened on the outer peripheral surface of the rotor, and surrounding the outer periphery of the rotor A pump chamber in which the tip of the vane is in sliding contact with the rotor, the vane and the cam surface, the volume of the pump chamber is changed by the rotation of the rotor, and fluid is sucked and discharged; A suction port that opens to a suction region where the volume of the pump chamber expands, a discharge port that opens to a discharge region in which the volume of the pump chamber decreases as the rotor rotates, and a base end portion of a slit groove for storing a vane located in the suction region A discharge-side arc-shaped groove portion that communicates and introduces suction pressure, and a discharge-side arc-shaped groove portion that communicates with the proximal end portion of the vane storage slit groove located in the discharge region and introduces discharge pressure. The groove, with the groove aperture starting end in the rotational direction of the rotor consecutively provided, throttle groove is small to form a flow path cross-sectional area in the small size of the groove width and recess depth from the discharge side arcuate groove portion, the discharge side The cross-sectional area of the flow path is substantially the same from the base end connected to the arc-shaped groove to the tip in the circumferential direction, and the throttle groove extends in the circumferential direction beyond the terminal end of the suction port in the rotation direction of the rotor. This is a vane pump characterized in that it communicates with the base end portion of the slit groove for vane storage located in the region and is provided apart from the arcuate groove portion on the suction side.

  Further, a movable ring is disposed so as to be eccentrically movable around the outer periphery of the rotor, the inner peripheral surface of the movable ring is used as the cam surface, and the movable ring is biased in the direction of increasing the amount of eccentricity with the rotor to achieve a full cutoff pressure. When the discharge pressure exceeds the cutoff pressure, the movable ring moves against the spring force of the spring to reduce the eccentric amount, reducing the discharge amount, and the discharge pressure is the full cutoff pressure. When the value reaches, the eccentric amount of the movable ring disappears, and a variable displacement type in which the discharge amount is substantially zero may be used.

As described above in detail, in the invention described in claim 1, the discharge-side arc-shaped groove portion is provided with the throttle groove portion continuously provided at the start end in the rotation direction of the rotor, and the throttle groove portion has a groove width and a width larger than those of the discharge-side arc-shaped groove portion. The recess depth is made small and the channel cross-sectional area is made small, and the channel cross-sectional area is provided substantially the same from the base end connected to the discharge-side arcuate groove to the tip in the circumferential direction. And extending in the circumferential direction beyond the terminal end side of the suction port in the rotation direction, communicating with the base end portion of the vane storage slit groove located in the suction region, and spaced apart from the suction-side arcuate groove portion. For this reason, since the discharge pressure controlled to be throttled is introduced from the throttle groove portion to the base end portion of the vane housing slit groove on the terminal end side of the suction port, the vane can be prevented from being excessively pressed against the cam surface and the rotor is rotated. The rotational driving force can be reduced. In addition, since the throttle groove portion extending in the circumferential direction beyond the terminal end side of the suction port is connected to the start end of the discharge-side arc-shaped groove portion in the rotation direction of the rotor, the discharge-side arc-shaped groove portion in the rotation direction of the rotor Compared to a conventional pump that extends in the circumferential direction beyond the end of the suction port, the amount of fluid leakage from the discharge-side arcuate groove to the suction port can be reduced, and the volumetric efficiency of the pump can be improved. it can.

The invention according to claim 1, aperture Ri groove provided a flow path cross-sectional area from the base end to continuously provided on the discharge side arcuate groove portion to the circumferential direction of the distal end at substantially the same. For this reason, compared to a throttle groove with a shape in which the flow path cross-sectional area gradually decreases toward the tip, the discharge pressure can be smoothly introduced over the entire circumferential direction of the throttle groove, and the vane is pressed against the cam surface smoothly. be able to.

In addition to the invention of claim 1, the invention of claim 2 is arranged such that a movable ring is arranged so as to be eccentrically movable around the outer periphery of the rotor, the inner peripheral surface of the movable ring is a cam surface, and the movable ring is the rotor. When the discharge pressure exceeds the cutoff pressure, the movable ring moves against the spring force of the spring to decrease the amount of eccentricity. When the discharge amount is reduced and the discharge pressure reaches the full cut-off pressure, the movable ring is decentered and the variable displacement type is set so that the discharge amount is substantially zero. For this reason, as compared with the constant capacity type in which the discharge amount is substantially constant, the discharge amount can be made substantially zero at the full cutoff pressure, and the rotational driving force can be further reduced.

1 is a longitudinal sectional view of a variable displacement vane pump showing an embodiment of the present invention. It is sectional drawing along line AA of FIG. It is an expanded sectional view along line BB of FIG. 2 which showed a rotor, a vane, and a movable ring by the imaginary line. It is an expanded sectional view along line CC of FIG. 2 which showed the rotor, the vane, and the movable ring by an imaginary line.

Hereinafter, an embodiment of the present invention that is a variable displacement vane pump will be described with reference to the drawings.
1 and 2, reference numeral 1 denotes a pump body, which has a cylindrical hole 2 and a housing 4 that is connected to the cylindrical hole 2 and has a receiving hole 3 formed in a direction perpendicular to the direction in which the cylindrical hole 2 is drilled. And a cover 5 that closes the cylindrical hole 2. Reference numeral 6 denotes a disc-shaped second side plate housed in the cylindrical hole 2, which is disposed in contact with the bottom surface of the cylindrical hole 2 so as not to rotate. Reference numeral 7 denotes a disk-shaped first side plate that is spaced apart from the second side plate 6 in the axial direction and is disposed so as not to rotate in the cylindrical hole 2. A rotor 8 is rotatably accommodated in the cylindrical hole 2 and is arranged between the first side plate 7 and the second side plate 6. One side surface in the axial direction is the second side plate 6 and the other side surface in the axial direction. Are in sliding contact with the first side plate 7, respectively. The rotor 8 has a first shaft portion 8A protruding from one side surface and a second shaft portion 8B protruding from the other side surface. The first shaft portion 8A is pivotally supported on the housing 4 and has a tip projecting outside to be connected to an electric motor (not shown). The second shaft portion 8B is pivotally supported on the cover 5. Reference numeral 9 denotes a vane storage slit groove formed in the rotor 8 in the radial direction. The slit 9 opens on the outer peripheral surface of the rotor 8, and 11 are provided at equal intervals in the circumferential direction of the rotor 8. The vane storage slit groove 9 has a base end portion 10 inward in the radial direction, and the base end portion 10 is formed in a circular shape. A vane 11 is inserted into the slit groove 9 for storing the vane so as to be slidable in the radial direction. A movable ring 12 is disposed around the outer periphery of the rotor 8 and is disposed between the first side plate 7 and the second side plate 6 of the cylindrical hole 2 so as to be movable eccentrically with respect to the rotor 8 in the left-right direction in FIG. Provided. The inner surface of the movable ring 12 is a cam surface 13 and the tip of the vane 11 is in sliding contact. A pump chamber 14 is defined by the rotor 8, the vane 11, and the cam surface 13 of the movable ring 12, and the volume changes as the rotor 8 rotates in the arrow B direction.

  Reference numeral 15 denotes a suction flow path for sucking fluid, and 16 denotes a discharge flow path for discharging fluid, each of which is formed in the cover 5. Reference numeral 17 denotes a suction port that opens into a suction region in which the volume of the pump chamber 14 is increased, and includes a first suction port portion 17A and a second suction port portion 17B. As shown in FIGS. 3 and 4, the first suction port portion 17 </ b> A is formed in a semicircular recess in the side surface of the first side plate 7 that is in sliding contact with the other side surface of the rotor 8. Communicating with the suction flow path 15 through the communication holes 17C and 17D penetrating therethrough. The second suction port portion 17B has substantially the same shape as the first suction port portion 17A, and a second side plate in which one side surface of the rotor 8 is in sliding contact with the first suction port portion 17A and the axially opposed position via the rotor 8. A recess is formed in a semicircular shape on the side surface of 6. Reference numeral 18 denotes a discharge port that opens to a discharge region in which the volume of the pump chamber 14 is reduced, and includes a first discharge port portion 18A and a second discharge port portion 18B. The first discharge port portion 18A is formed at a position opposed to the first suction port portion 17A in the radial direction through a center, and is formed in a semicircular arc shape on the side surface of the first side plate 7 in which the other side surface of the rotor 8 is in sliding contact. Are connected to the discharge flow path 16 through communication holes 18C, 18D, and 18E that pass through the first side plate 7. The second discharge port portion 18B has substantially the same shape as the first discharge port portion 18A, and a second side plate in which one side surface of the rotor 8 is in sliding contact with the first discharge port portion 18A and the axially opposed position via the rotor 8. A recess is formed in a semicircular shape on the side surface of 6.

  The volume of the pump chamber 14 is changed by the rotation of the rotor 8 in the direction of arrow B, and the fluid sucked from the suction port 17 is transported and discharged from the discharge port 18. The pump chamber 14 acts on the cam surface 13 of the movable ring 12 so as to move the movable ring 12 in the direction of decreasing the amount of eccentricity with the rotor 8 (leftward in FIG. 1). Reference numeral 19 denotes a lid member that closes the opening of the collection hole 3 and is fixed to the housing 4. Reference numeral 20 denotes a spring accommodated in the accommodation hole 3, and a holder 21 is attached to one end portion, and a spring receiving member 22 is attached to the other end portion facing the one end portion in the axial direction. The spring 20 abuts on the outer peripheral surface of the movable ring 12 via the holder 21 and urges the movable ring 12 in the direction of increasing the amount of eccentricity (right direction in FIG. 1). A pressure adjusting member 23 is screwed to the lid member 19 so as to be rotatable. The pressure adjusting member 23 is brought into contact with the other end of the spring 20 via a spring receiving member 22, and is provided so as to be movable forward and backward by a rotating operation. The pressure adjusting member 23 is advanced and retracted by a turning operation, and the spring 20 is expanded and contracted to change the spring force, so that the full cut-off pressure can be freely changed. Reference numeral 24 denotes a lock nut member screwed to the pressure adjusting member 23, which is provided so as to be able to come into contact with and separate from the lid member 19, and restricts the rotation operation of the pressure regulating member 23 by contact with the lid member 19.

  Reference numeral 25 denotes a guide screw member screwed into the housing 4, which is in contact with the outer peripheral surface of the movable ring 12 in a direction substantially perpendicular to the contact portion of the holder 21, and the cam surface 13 of the movable ring 12 corresponding to the position of the discharge port 18. 1 is received so as to guide the movement of the movable ring 12 in the left-right direction in FIG. The guide screw member 25 is provided so as to be able to advance and retract by a turning operation, and the position of the movable ring 12 in the vertical direction in FIG. Reference numeral 26 denotes a lock nut member screwed into the guide screw member 25, which is provided so as to be able to contact with and separate from the housing 4, and restricts the rotation operation of the guide screw member 25 by contact with the housing 4. A discharge amount adjusting member 27 screwed into the housing 4 is in contact with the outer peripheral surface of the movable ring 12 at a position facing the holder 21 and regulates the maximum eccentric amount of the movable ring 12 to set the maximum discharge amount. Reference numeral 28 denotes a lock nut member screwed into the discharge amount adjusting member 27, which is provided so as to be able to come into contact with and separate from the pump main body 1, and regulates the turning operation of the discharge amount adjusting member 27 by contact with the pump main body 1.

Reference numeral 29 denotes a suction-side arcuate groove portion that communicates with the base end portion 10 of the vane storage slit groove 9 located in the suction region and introduces suction pressure. Reference numeral 30 denotes a base end portion of the vane storage slit groove 9 positioned in the discharge region. A discharge-side arcuate groove portion that communicates with 10 and introduces discharge pressure will be described in detail below with reference to FIGS. 3 and 4.
The suction-side arcuate groove 29 is composed of a first suction-side arcuate groove 29A provided in the first side plate 7 and a second suction-side arcuate groove 29B provided in the second side plate 6. As shown in FIG. 3, the first suction-side arcuate groove 29A is provided at substantially the same position in the radial direction as the base end portion 10 of the vane storage slit groove 9 at a radially inward position from the first suction port portion 17A. In addition, a recess is formed in a semicircular arc shape, and the circumferential length is approximately equal to the two pump chambers 14. The first suction-side arc-shaped groove 29A communicates with the suction flow path 15 through a communication hole 29C that is continuous with the bottom surface and penetrates the first side plate 7. As shown in FIG. 4, the second suction side arcuate groove portion 29 </ b> B has substantially the same shape as the first suction side arcuate groove portion 29 </ b> A, and is opposed to the first suction side arcuate groove portion 29 </ b> A in the axial direction via the rotor 8. A depression is formed in the second side plate 6. The second suction-side arcuate groove portion 29 </ b> B forms a substantially V-shaped groove 29 </ b> D at the start end in the rotation direction B of the rotor 8. The groove 29D gradually communicates the vane storage slit groove 9 with the second suction-side arcuate groove portion 29B in the rotation of the rotor 8.

  The discharge-side arcuate groove 30 is composed of a first discharge-side arcuate groove 30A provided on the first side plate 7 and a second discharge-side arcuate groove 30B provided on the second side plate 6. As shown in FIG. 3, the first discharge-side arcuate groove portion 30A is concentric with the first suction-side arcuate groove portion 29A and is provided at substantially the same position in the radial direction as the base end portion 10 of the vane storage slit groove 9. A recess is formed in an arc shape, and the circumferential length is approximately equal to that of the six pump chambers 14. The first discharge-side arcuate groove portion 30A communicates with the discharge flow path 16 through communication holes 30C, 30D, and 30E that are connected to the bottom surface and penetrate the first side plate 7. As shown in FIG. 4, the second discharge-side arcuate groove portion 30 </ b> B has substantially the same shape as the first discharge-side arcuate groove portion 30 </ b> A, and is opposed to the first discharge-side arcuate groove portion 30 </ b> A in the axial direction via the rotor 8. A depression is formed in the second side plate 6.

  Reference numeral 31 denotes a throttle groove portion that throttles the fluid in the discharge-side arcuate groove portion 30 and introduces it into the vane storage slit groove 9, and is connected to the starting end of the discharge-side arcuate groove portion 30 in the rotational direction B of the rotor 8. The throttle groove 31 is composed of a first throttle groove 31A provided continuously with the start end of the first discharge-side arcuate groove 30A and a second throttle groove 31B provided continuously with the start end of the second discharge-side arcuate groove 30B. . Both throttle groove portions 31A, 31B are concentric with both discharge-side arcuate groove portions 30A, 30B, are provided at substantially the same position in the radial direction as the base end portion 10 of the vane storage slit groove 9, and are recessed in a semicircular arc shape. . Both throttle groove portions 31A and 31B extend in the circumferential direction beyond the end sides of both suction port portions 17A and 17B constituting the suction port 17, and are provided with a circumferential length dimension substantially equal to that of one pump chamber 14. The tip is separated from the end of both suction side arcuate grooves 29A, 29B. The separation dimension between the distal ends of both throttle grooves 31A, 31B and the terminal ends of both suction side arcuate grooves 29A, 29B is provided slightly larger than the circular dimension of the base end portion 10 of the vane storage slit groove 9, and the rotor 8 rotates. The base end portion 10 of the vane storage slit groove 9 is set so as to communicate with both throttle groove portions 31A and 31B after blocking communication with both suction side arcuate groove portions 29A and 29B. Both throttle groove portions 31A and 31B are formed so that the groove width and the recess depth are smaller than those of both discharge-side arcuate groove portions 30A and 30B, and the flow passage cross-sectional area is made smaller. Both throttle groove portions 31A and 31B have substantially the same channel cross-sectional area in the entire circumferential direction from the base end to the tip end connected to both discharge-side arcuate groove portions 30A and 30B.

  As shown in FIG. 4, 32 is a groove formed in the second side plate 6, which is provided at the end in the rotational direction B of the rotor 8 of the second suction port portion 17 </ b> B constituting the suction port 17, and cuts off the flow path toward the tip. It is formed in a substantially V shape that gradually reduces the area, and the circumferential length is slightly smaller than the thickness of the vane 11. The groove 32 allows the pressure in the pump chamber 14 to escape to the second suction port portion 17B until the pump chamber 14 that moves from the suction region in the rotation of the rotor 8 is in a closed state. Suppresses the rise. At the start end in the rotation direction B of the rotor 8 of the second discharge side arcuate groove portion 30B constituting the discharge side arcuate groove portion 30B and at the end of the second suction port portion 17B constituting the suction port 17 in the rotation direction B of the rotor 8 The distance from the tip of the provided groove 32 is slightly smaller than the thickness of the vane 11. Reference numeral 33 denotes a groove provided at the start end of the second suction port portion 17B in the rotation direction B of the rotor 8, and is formed in a substantially V shape that gradually reduces the cross-sectional area of the flow path toward the tip, and the circumferential length is set to the vane 11. The thickness dimension is approximately 2.5 times. The groove 33 gradually increases the opening degree of communication with the second suction port portion 17B of the pump chamber 14 in the closed state when the pump chamber 14 shifts from the closed state to the suction region in the rotation of the rotor 8. 14 to suppress a sudden drop in the confining pressure. Reference numeral 34 denotes a groove provided at the start end of the second discharge port portion 18B in the rotation direction B of the rotor 8 and is formed in a substantially V shape that gradually decreases the cross-sectional area of the flow path toward the tip, and the circumferential length is set to the vane 11. The thickness dimension is approximately 2.5 times. The groove 34 gradually increases the opening degree of communication with the second discharge port portion 18B of the pump chamber 14 in the closed state when the pump chamber 14 shifts from the closed state to the discharge region when the rotor 8 rotates. The rapid increase of the 14 confinement pressure is suppressed. A groove 35 is provided at the end of the second discharge port portion 18B in the rotational direction B of the rotor 8, and is formed in a substantially V shape that gradually decreases the cross-sectional area of the flow path toward the tip, and the circumferential length is set to the vane 11. It is provided slightly smaller than the thickness dimension. The groove 35 allows the pressure in the pump chamber 14 to escape to the second discharge port portion 18B until the pump chamber 14 moving from the discharge region in the rotation of the rotor 8 is in a closed state, and the pump chamber 14 has a significant increase in the closing pressure. Suppress.

Next, the operation of this configuration will be described.
In the state of FIG. 1, when the movable ring 12 is at the maximum eccentric position and the rotor 8 is rotated in the direction of arrow B, the fluid sucked into the pump chamber 14 from the suction port 17 is discharged from the discharge port 18 to obtain the maximum discharge amount. It is done. When the acting force due to the discharge pressure acting in the left direction in FIG. 1 on the cam surface 13 of the movable ring 12 exceeds the set pressure due to the spring force of the spring 20, the movable ring 12 decreases the eccentric amount in the left direction in FIG. 1. The discharge amount is reduced by being guided by the guide screw member 25 and the movable ring 12 is substantially concentric with the rotor 8, so that the discharge amount becomes zero. When the discharge pressure decreases below the set pressure due to the decrease in the discharge amount, the movable ring 12 is guided by the guide screw member 25 in the right direction in FIG. 1 by the spring force of the spring 20 and moves to increase the discharge amount.

  As the rotor 8 rotates in the direction of arrow B, suction pressure is introduced from the suction-side arcuate groove 29 in the suction region to the base end portion 10 of the vane storage slit groove 9, and the discharge-side arcuate groove in the discharge region. The discharge pressure is introduced from 30 and the vane 11 is pressed against the cam surface 13. Further, between the suction region and the discharge region, a discharge pressure controlled by the throttle groove 31 is introduced into the base end portion 10 of the vane housing slit groove 9 to press the vane 11 against the cam surface 13.

  With this operation, the discharge-side arc-shaped groove 30 is continuously provided with the throttle groove 31 at the start end in the rotation direction B of the rotor 8, and the throttle groove 31 has a smaller channel cross-sectional area than the discharge-side arc-shaped groove 30. The throttle groove portion 31 extends in the circumferential direction beyond the terminal end side of the suction port 17 in the rotation direction B of the rotor 8, communicates with the base end portion 10 of the vane storage slit groove 9 located in the suction region, and sucks the suction groove 17. The side arc-shaped groove 29 was provided apart from the side arc-shaped groove 29. For this reason, since the discharge pressure controlled to be throttled is introduced from the throttle groove 31 to the base end portion 10 of the slit groove 9 for vane storage on the terminal end side of the suction port 17, the vane 11 is excessively pressed against the cam surface 13. The rotational driving force for rotating the rotor 8 can be reduced. Further, since the throttle groove 31 extending in the circumferential direction beyond the terminal end of the suction port 17 is connected to the start end of the discharge-side arc-shaped groove 30 in the rotation direction B of the rotor 8, the discharge in the rotation direction of the rotor is performed. Compared to a conventional pump in which the starting end of the side arc-shaped groove portion extends in the circumferential direction beyond the terminal end side of the suction port, the amount of fluid leakage from the discharge-side arc-shaped groove portion 30 to the suction port 17 can be reduced, and the volume of the pump Efficiency can be improved.

  In addition, the throttle groove 31 has substantially the same flow path cross-sectional area from the base end connected to the discharge-side arcuate groove 30 to the tip in the circumferential direction. For this reason, it is possible to easily introduce the discharge pressure over the entire area of the throttle groove 31 as compared with a throttle groove having a shape in which the cross-sectional area of the flow path gradually decreases toward the tip. Can be pressed.

  Further, a separation dimension between the starting end of the discharge-side arcuate groove portion 30 in the rotation direction B of the rotor 8 and the terminal end of the suction port 17 is set slightly smaller than the thickness dimension of the vane 11. For this reason, in the rotational direction B of the rotor 8, immediately after the vane 11 passes the end of the suction port 17, the communication of the base end portion 10 of the vane storage slit groove 9 is changed from the throttle groove portion 31 to the discharge-side arcuate groove portion 30. Therefore, as the vane 11 moves from the suction region to the discharge region, the pressure introduced into the base end portion 10 of the vane storage slit groove 9 can be increased, and the vane 11 can be pressed well against the cam surface 13 and the pump This can be done without reducing the sealing performance of the chamber 14.

  Further, a groove 32 is provided at the end of the suction port 17 in the rotation direction B of the rotor 8, and the circumferential length of the groove 32 is slightly smaller than the thickness of the vane 11. For this reason, the pressure in the pump chamber 14 can be released from the groove 32 to the suction port 17 until the pump chamber 14 that moves from the suction region is in a closed state, and the pumping pressure in the pump chamber 14 is significantly increased. Can be suppressed.

  Further, a movable ring 12 is disposed so as to be movable eccentrically around the outer periphery of the rotor 8, the inner peripheral surface of the movable ring 12 is a cam surface 13, and the movable ring 12 is urged in an increasing amount of eccentricity with the rotor 8. When a spring 20 for setting a full cut-off pressure is provided, and the discharge pressure exceeds the cut-off pressure, the movable ring 12 moves so as to reduce the eccentric amount against the spring force of the spring 20 to reduce the discharge amount, When the discharge pressure reaches the full cut-off pressure, the movable ring 12 is decentered and the variable displacement type is set so that the discharge amount is substantially zero. For this reason, the discharge amount can be made substantially zero at the full cutoff pressure, and the rotational driving force can be further reduced.

  In the above-described embodiment, the suction port 17, the discharge port 18, the suction side arcuate groove portion 29, the discharge side arcuate groove portion 30, and the throttle groove portion 31 are provided on both the first side plate 7 and the second side plate 6, respectively. However, at least one of them may be provided. Further, the groove 32 provided at the end of the suction port 17 is provided in the second suction port portion 17B, but may be provided in the first suction port portion 17A or in both suction port portions 17A and 17B. Further, when the discharge pressure reaches the full cut-off pressure, the variable displacement type is set so that the discharge amount is substantially zero. However, it is needless to say that a constant capacity type where the discharge amount is substantially constant may be used.

1: pump main body 8: rotor 9: slit groove 10 for storing vanes: base end portion 11: vane 13: cam surface 14: pump chamber 17: suction port 17A: first suction port portion 17B: second suction port portion 18: Discharge port 18A: first discharge port portion 18B: second discharge port portion 29: suction side arcuate groove portion 29A: first suction side arcuate groove portion 29B: second suction side arcuate groove portion 30: discharge side arcuate groove portion 30A: First discharge side arcuate groove portion 30B: second discharge side arcuate groove portion 31: throttle groove portion 31A: first throttle groove portion 31B: second throttle groove portion

Claims (2)

A rotor provided rotatably in the pump body, a plurality of vane storage slit grooves formed in the rotor and slidably inserted in the radial direction, and opened on the outer peripheral surface of the rotor, and surrounding the outer periphery of the rotor A pump chamber in which the tip of the vane is slidably contacted, a rotor, the vane, and the cam surface, the volume of which is changed by the rotation of the rotor and the fluid is sucked and discharged, and the volume of the pump chamber according to the rotation of the rotor A suction port that opens to a suction region where the volume of the pump chamber expands, a discharge port that opens to a discharge region in which the volume of the pump chamber decreases as the rotor rotates, and a base end portion of a slit groove for storing a vane located in the suction region A discharge-side arc-shaped groove portion that communicates and introduces suction pressure, and a discharge-side arc-shaped groove portion that communicates with the proximal end portion of the vane storage slit groove located in the discharge region and introduces discharge pressure. The groove, with the groove aperture starting end in the rotational direction of the rotor consecutively provided, throttle groove is small to form a flow path cross-sectional area in the small size of the groove width and recess depth from the discharge side arcuate groove portion, the discharge side The cross-sectional area of the flow path is substantially the same from the base end connected to the arc-shaped groove to the tip in the circumferential direction, and the throttle groove extends in the circumferential direction beyond the terminal end of the suction port in the rotation direction of the rotor. A vane pump, wherein the vane pump communicates with a base end portion of a slit groove for storing vanes located in a region and is separated from an arcuate groove portion on the suction side. A movable ring is arranged around the outer periphery of the rotor so that it can be moved eccentrically. The inner peripheral surface of the movable ring is used as the cam surface, and the movable ring is biased in the direction of increasing the amount of eccentricity with the rotor to set the full cutoff pressure. When the discharge pressure exceeds the cutoff pressure, the movable ring moves against the spring force of the spring to reduce the eccentric amount, reducing the discharge amount, and the discharge pressure reaches the full cutoff pressure. The vane pump according to claim 1, wherein the variable ring type is configured such that the eccentric amount of the movable ring disappears and the discharge amount is substantially zero.

Images