JP7037461B2 - Vane pump - Google Patents

Description

The present invention relates to a vane pump.

In Patent Document 1, a rotor in which a plurality of slits are formed in the radial direction, a plurality of vanes slidably housed in each slit and whose tip surface is in sliding contact with the cam surface of the cam ring, and adjacent vanes are defined. A vane pump comprising a pump chamber to be pumped, two suction ports to guide the working fluid sucked into the pump chamber, and two discharge ports to guide the working fluid discharged from the pump chamber is described.

Japanese Unexamined Patent Publication No. 2013-050067

In the vane pump described in Patent Document 1, suction ports and discharge ports are alternately arranged along the rotation direction of the rotor. Therefore, the suction and discharge of the working fluid are performed in a relatively short period of time. In general, if the suction period is short, the working fluid cannot be sufficiently sucked, and if the boosting period is short, the working fluid cannot be sufficiently boosted. Therefore, in a vane pump having two suction ports and two discharge ports like the vane pump described in Patent Document 1, the period from suction to discharge is shortened, and each discharge port is caused by insufficient suction or boosting of the working fluid. The discharge pressure of the hydraulic fluid discharged through may become unstable.

The present invention has been made in view of the above problems, and an object of the present invention is to stabilize the discharge pressure of the vane pump.

In the present invention, the vane pump is driven by rotation, a plurality of vanes slidably inserted into a plurality of slits formed radially in the rotor, and the tip of the vane is in sliding contact with the rotation of the rotor. A cam ring having a peripheral cam surface, a pump chamber defined between the adjacent vanes, a rotor and a cam ring, a suction port for guiding the working fluid sucked into the pump chamber, and a working fluid discharged from the pump chamber. A first discharge port and a second discharge port are provided, and the suction port, the first discharge port, and the second discharge port are arranged in this order along the rotation direction of the rotor, and the suction port and the pump chamber communicate with each other. The length of the suction section is equal to or greater than the total length of the first discharge section in which the first discharge port and the pump chamber communicate with each other and the length of the second discharge section in which the second discharge port and the pump chamber communicate with each other. It is characterized by being set to .

In the present invention, the suction port, the first discharge port and the second discharge port are arranged in this order along the rotation direction of the rotor. That is, the working fluid sucked in by one suction port is first discharged through the first discharge port and then discharged through the second discharge port. In this way, by making one suction port for the two discharge ports, the suction period for sucking the working fluid becomes long, so that the working fluid can be sufficiently sucked and the working fluid is sucked. Since the period from to discharge to discharge is long, it is possible to discharge a sufficiently pressurized working fluid through each discharge port.

Further, in the present invention, the volume of the pump chamber expands with the rotation of the rotor in the suction section where the suction port and the pump chamber communicate with each other, and the first discharge port following the suction section and the pump chamber communicate with each other. In the discharge section, it shrinks with the rotation of the rotor, and in the second discharge section where the second discharge port following the first discharge section and the pump chamber communicate with each other, it further shrinks with the rotation of the rotor and continues to the second discharge section. It is characterized by expanding again in the inhalation section.

In the present invention, the working fluid sucked in one suction section is first discharged in the first discharge section and then discharged in the second discharge section. In this way, by making the suction section one for the two discharge sections, the suction period for sucking the working fluid becomes long, so that the working fluid can be sufficiently sucked, and the working fluid is sucked. Since the period from to discharge to discharge is long, it is possible to discharge a sufficiently pressurized working fluid in each discharge section.

Further, in the present invention, a first transition section in which the pump chamber is closed is provided between the suction section and the first discharge section, and the pump chamber is closed between the first discharge section and the second discharge section. The second transition section is provided, and the volume change rate of the pump chamber in the second transition section is smaller than the volume change rate of the pump chamber in the first transition section.

In the present invention, the volume change rate of the pump chamber in the second transition section is set smaller than the volume change rate of the pump chamber in the first transition section. By reducing the volume change rate of the pump chamber in the second transition section in this way, it is possible to suppress fluctuations in the pressure in the pump chamber moving in the second transition section, and at the same time, discharge in the subsequent second discharge section. The pressure of the working fluid is stabilized.

Further, the present invention further comprises a back pressure chamber in which the vane pump is partitioned by the base end portion of the vane in the slit, and the back pressure chamber in the suction section is provided in the back pressure chamber on the first discharge section side. , The working fluid discharged through the first discharge port is guided, and the working fluid discharged through the second discharge port is guided to the back pressure chamber on the second discharge section side of the back pressure chambers in the suction section. It is characterized by being inhaled.

In the present invention, the working fluid discharged through the first discharge port is guided to the back pressure chamber on the first discharge section side of the back pressure chamber in the suction section, and the back pressure chamber in the suction section The working fluid discharged through the second discharge port is guided to the back pressure chamber on the second discharge section side. Therefore, when the pressure of the working fluid discharged through the first discharge port becomes low, the pressure of the back pressure chamber on the first discharge section side of the back pressure chamber in the suction section also becomes low. Therefore, the force with which the vane is pressed against the inner peripheral cam surface of the cam ring by the pressure of the back pressure chamber is reduced. As a result, the frictional force generated between the vane and the inner peripheral cam surface is reduced, and as a result, the torque for driving the vane pump can be reduced.

Further, in the present invention, the vane pump extends from the opening edge of the first discharge port in the direction opposite to the rotation direction of the rotor, and the vane pump is opposite to the rotation direction of the rotor from the opening edge of the second discharge port. A second notch extending in the direction of the above is further provided, and the length of the first notch in the circumferential direction is longer than the length of the second notch in the circumferential direction.

In the present invention, the length of the first notch in the circumferential direction is set longer than the length of the second notch in the circumferential direction. By lengthening the first notch in this way, it becomes possible to stabilize the pressure in the pump chamber in the first transition section where the pressure in the pump chamber becomes relatively unstable, and as a result, the pressure is discharged through the first discharge port. The pressure of the working fluid can be stabilized. Further, by shortening the length of the second notch, the inflow of the working fluid from the second discharge port to the pump chamber through the second notch is suppressed, and the pressure of the second discharge port is prevented from dropping. As a result, the pressure of the working fluid discharged through the second discharge port can be stabilized.

Further, in the present invention, the vane pump extends from the opening edge of the first discharge port in the direction opposite to the rotation direction of the rotor, and the vane pump is opposite to the rotation direction of the rotor from the opening edge of the second discharge port. A second notch extending in the direction of It is characterized in that it is larger than the cross-sectional area of the second notch at a position separated by a predetermined distance in the circumferential direction.

In the present invention, the cross-sectional area of the first notch at a position separated by a predetermined distance in the circumferential direction from the opening edge of the first discharge port is separated by a predetermined distance in the circumferential direction from the opening edge of the second discharge port. It is set larger than the cross-sectional area of the second notch at the position. By increasing the cross-sectional area of the first notch in this way, it becomes possible to stabilize the pressure in the pump chamber in the first transition section where the pressure in the pump chamber becomes relatively unstable, and as a result, the pressure in the first discharge port can be stabilized. The pressure of the working fluid discharged through can be stabilized. Further, by reducing the cross-sectional area of the second notch, the inflow of the working fluid from the second discharge port to the pump chamber through the second notch is suppressed, and the pressure of the second discharge port is prevented from dropping. As a result, the pressure of the working fluid discharged through the second discharge port can be stabilized.

Further, the present invention is characterized in that the pressure of the working fluid discharged through the second discharge port is higher than the pressure of the working fluid discharged through the first discharge port.

In the present invention, the pressure of the working fluid discharged through the second discharge port is higher than the pressure of the working fluid discharged through the first discharge port. In this way, even if there is only one suction port, a relatively low pressure working fluid is supplied from the first discharge port, and a relatively high pressure working fluid is supplied from the second discharge port to operate different pressures. It is possible to supply two stable pressures with little fluctuation to a fluid pressure device that requires fluid.

According to the present invention, the discharge pressure of the vane pump can be stabilized.

It is sectional drawing of the vane pump which concerns on embodiment of this invention. It is sectional drawing around the pump chamber along the line II-II of FIG. It is a top view of the body side side plate seen from the cam ring side. It is a schematic diagram which superposed the cross section along the line AA of FIG. 3 and the cross section along the line BB of FIG. It is a top view of the cover side side plate seen from the cam ring side. It is a figure which showed the profile of the inner circumference cam surface of a cam ring.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The vane pump 100 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view of the vane pump 100 according to the embodiment of the present invention, and FIG. 2 is a partially enlarged cross-sectional view taken along the line II-II of FIG.

The vane pump 100 is used as a fluid pressure supply source for supplying a pressurized working fluid to a fluid pressure device mounted on a vehicle, for example, a power steering device, a continuously variable transmission, or the like. The working fluid is oil, other water-soluble alternative solutions, and the like.

As shown in FIGS. 1 and 2, the vane pump 100 includes a pump body 10 in which a housing recess 10a is formed, a pump cover 20 that covers the housing recess 10a and is fixed to the pump body 10, a pump body 10 and a pump cover 20. A drive shaft 1 rotatably supported via bearings 11 and 12, a rotor 2 connected to the drive shaft 1 and housed in a housing recess 10a, and a plurality of slits 2a radially formed in the rotor 2. It includes a plurality of vanes 3 slidably accommodated, and a cam ring 4 having an inner peripheral cam surface 4a that accommodates the rotor 2 and the vanes 3 and is in sliding contact with the tip portion 3a of the vanes 3.

The vane pump 100 is driven by an engine or the like (not shown), and the rotor 2 connected to the drive shaft 1 is rotationally driven to generate fluid pressure.

As shown in FIG. 2, the vane 3 is slidably inserted into each slit 2a, and has a tip portion 3a which is an end portion protruding from the slit 2a and a base end which is an end portion opposite to the tip portion 3a. It has a part 3b and. A back pressure chamber 5 is formed on the bottom side of the slit 2a, which is partitioned by the base end portion 3b of the vane 3. Hydraulic oil as a working fluid is guided to the back pressure chamber 5, and the vane 3 is pressed in a direction protruding from the slit 2a by the pressure of the back pressure chamber 5.

The cam ring 4 is an annular member having an inner peripheral cam surface 4a formed on the inner peripheral surface. When the vane 3 is pressed in the direction of protruding from the slit 2a by the pressure of the back pressure chamber 5, the tip portion 3a of the vane 3 is in sliding contact with the inner peripheral cam surface 4a of the cam ring 4. As a result, the pump chamber 6 is defined inside the cam ring 4 by the outer peripheral surface of the rotor 2, the inner peripheral cam surface 4a of the cam ring 4, and the adjacent vanes 3.

Since the inner peripheral cam surface 4a is formed with a predetermined profile, the volume of the pump chamber 6 between the vanes 3 in sliding contact with the inner peripheral cam surface 4a repeats expansion and contraction as the rotor 2 rotates. The hydraulic oil is sucked into the pump chamber 6 in the section where the volume of the pump chamber 6 gradually increases, and the hydraulic oil is discharged from the pump chamber 6 in the section where the volume of the pump chamber 6 gradually decreases.

The vane pump 100 is provided on one end side in the axial direction of the rotor 2 and is provided on the side plate 30 on the body side that abuts on one side surface of the rotor 2 and the cam ring 4, and is provided on the other end side in the axial direction of the rotor 2 and the rotor 2 and the cam ring. A cover-side side plate 40 that abuts on the other side surface of 4 is further provided.

The body-side side plate 30 is a flat plate member provided between the bottom surface of the accommodating recess 10a and the rotor 2, and the rotor 2 is in sliding contact with the body-side side plate 30 and the cam ring 4 is in contact with the body-side side plate 30.

On the other hand, the cover-side side plate 40 is a flat plate-shaped member provided between the rotor 2 and the pump cover 20, and the rotor 2 is in sliding contact with the cover-side side plate 40 and the cam ring 4 is in contact with the cover-side side plate 40. In this way, the body-side side plate 30 and the cover-side side plate 40 are arranged so as to face each other with the rotor 2 and the cam ring 4 interposed therebetween.

When the pump cover 20 is attached to the pump body 10 in a state where the body side side plate 30, the rotor 2, the cam ring 4, and the cover side side plate 40 are accommodated in the accommodating recess 10a of the pump body 10, the accommodating recess 10a is accommodated. Is sealed.

Two high-pressure chambers, a first high-pressure chamber 14 and a second high-pressure chamber 15, which are partitioned by the pump body 10 and the body-side side plate 30, are formed on the bottom surface side of the accommodating recess 10a of the pump body 10. The first high-pressure chamber 14 and the second high-pressure chamber 15 communicate with a fluid pressure device provided outside the vane pump 100 through a passage (not shown).

On the other hand, the pump cover 20 is formed with a suction pressure chamber 21 that opens on the pump body 10 side. The suction pressure chamber 21 communicates with a tank provided outside the vane pump 100 through a passage (not shown).

Further, on the inner peripheral surface of the accommodating recess 10a, a groove-shaped detour passage 13 formed toward the body side side plate 30 is provided. The detour passage 13 communicates with the suction pressure chamber 21 formed in the pump cover 20.

Next, the specific shapes of the body-side side plate 30 and the cover-side side plate 40 will be described with reference to FIGS. 3 to 5. 3 is a plan view of the body side side plate 30 seen from the cam ring 4 side in FIG. 1, and FIG. 4 shows a cross section of a first notch 31a described later along the line AA of FIG. 3 and B of FIG. It is a schematic view showing the cross section of the second notch 32a which will be described later superimposed along the line B, and FIG. 5 is a plan view of the cover side side plate 40 seen from the cam ring 4 side in FIG.

As shown in FIG. 3, the body-side side plate 30 has a sliding contact surface 30a through which the side surfaces of the rotor 2 and the vane 3 are in sliding contact, a through hole 30b through which the drive shaft 1 is inserted, and a sliding contact surface 30a radially outward. It has a suction recess 33 as a suction port formed by notching toward the surface, and a first discharge port 31 and a second discharge port 32 which are formed so as to penetrate in the axial direction and open to the sliding contact surface 30a. The rotor 2 and the vane 3 are in sliding contact with the body side side plate 30 along the arrow shown in FIG.

The first discharge port 31 and the second discharge port 32 are elongated holes formed in an arc shape along the circumferential direction, and the first discharge port 31 communicates the pump chamber 6 and the first high pressure chamber 14 to pump. The hydraulic oil discharged from the chamber 6 is guided to the first high-pressure chamber 14, and the second discharge port 32 communicates the pump chamber 6 and the second high-pressure chamber 15 with the hydraulic oil discharged from the pump chamber 6 to the second. Lead to the high pressure chamber 15.

The suction recess 33 communicates with the pump chamber 6 through the opening in the sliding contact surface 30a, and communicates with the detour passage 13 formed on the inner peripheral surface of the accommodating recess 10a through the opening on the outer peripheral surface of the body side side plate 30. ing. That is, the pump chamber 6 and the suction pressure chamber 21 are communicated with each other by the suction recess 33 and the detour passage 13, and the suction recess 33 guides the hydraulic oil sucked into the pump chamber 6 to the pump chamber 6. There is.

The suction recess 33, the first discharge port 31, and the second discharge port 32 are arranged at predetermined intervals in the circumferential direction, and are arranged along the direction of the arrow shown in FIG. 3, which is the rotation direction of the rotor 2. The suction recess 33, the first discharge port 31, and the second discharge port 32 are arranged in this order.

The range in which the suction recess 33 is formed is the suction section SS1 which is a section in which the hydraulic oil is sucked into the pump chamber 6 because the pump chamber 6 and the suction pressure chamber 21 communicate with each other through the suction recess 33. On the other hand, in the range where the first discharge port 31 is formed, since the pump chamber 6 and the first high pressure chamber 14 communicate with each other through the first discharge port 31, the hydraulic oil flows from the pump chamber 6 to the first high pressure chamber 14. The first discharge section DS1 is the discharge section, and the range in which the second discharge port 32 is formed is the pump chamber 6 because the pump chamber 6 and the second high pressure chamber 15 communicate with each other through the second discharge port 32. This is the second discharge section DS2, which is the section in which the hydraulic oil is discharged to the second high-pressure chamber 15.

Further, between the suction section SS1 and the first discharge section DS1, there is a first transition section TS1 in which the inflow and outflow of hydraulic oil to the pump chamber 6 is blocked, and between the first discharge section DS1 and the second discharge section DS2. Is the second transition section TS2 in which the inflow and outflow of hydraulic oil to the pump chamber 6 is blocked, and the inflow and outflow of hydraulic oil to the pump chamber 6 is blocked between the second discharge section DS2 and the suction section SS1. 3 Transition section TS3.

Further, the sliding contact surface 30a of the body side side plate 30 has a substantially V-shaped groove extending from the opening edge of the first discharge port 31 in a direction opposite to the rotation direction of the rotor 2. A first notch 31a and a second notch 32a having a substantially V-shaped cross-sectional shape extending from the opening edge of the second discharge port 32 in a direction opposite to the rotation direction of the rotor 2 are provided. .. The first notch 31a and the second notch 32a are formed on the outer peripheral side of the outer peripheral surface of the rotor 2 and on the inner peripheral side of the inner peripheral cam surface 4a of the cam ring 4.

Both the first notch 31a and the second notch 32a are formed in a tapered shape in which the width in the radial direction becomes smaller toward the direction opposite to the rotation direction of the rotor 2. The depth of the first notch 31a at the opening edge of the first discharge port 31 is substantially the same as the depth of the second notch 32a at the opening edge of the second discharge port 32, and the depth of the opening of the first discharge port 31 The radial width of the first notch 31a at the edge is approximately the same as the radial width of the second notch 32a at the opening edge of the second discharge port 32. On the other hand, the first length L1 which is the length of the first notch 31a in the circumferential direction is set longer than the second length L2 which is the length of the second notch 32a in the circumferential direction.

Therefore, as shown in FIG. 4, the cross-sectional area S1 of the first notch 31a at a position separated by a predetermined distance L0 in the circumferential direction from the opening edge of the first discharge port 31 is the opening edge of the second discharge port 32. It is larger than the cross-sectional area S2 of the second notch 32a at a position separated by the same predetermined distance L0 in the circumferential direction from the portion. 4 shows a cross section of the first notch 31a at a position separated by a predetermined distance L0 in the circumferential direction from the opening edge of the first discharge port 31 along the line AA of FIG. 3, and BB of FIG. The cross section of the second notch 32a at a position separated by a predetermined distance L0 in the circumferential direction from the opening edge of the second discharge port 32 along the line is shown superimposed. The cross-sectional shape of the first notch 31a and the second notch 32a is not limited to a substantially V shape, and may be a rectangular shape, a semicircular shape, or a substantially U shape.

On the other hand, as shown in FIG. 5, the cover-side side plate 40 has a sliding contact surface 40a through which the side surfaces of the rotor 2 and the vane 3 are in sliding contact, a through hole 40b through which the drive shaft 1 is inserted, and a part of the outer edge portion thereof. A suction notch 41 as a suction port formed by the notch, a first facing groove 43 formed at a position facing the first discharge port 31 across the pump chamber 6, and a first facing groove 43 sandwiching the pump chamber 6 are interposed therebetween. 2 It has a second facing groove 44 formed at a position facing the discharge port 32. The rotor 2 and the vane 3 are in sliding contact with the cover side side plate 40 along the arrow shown in FIG.

The suction notch 41 is formed along the circumferential direction over the same range as the suction recess 33, and the pump chamber 6 and the suction pressure chamber 21 communicate with each other through the suction notch 41. As described above, since the pump chamber 6 and the suction pressure chamber 21 communicate with each other through the suction recess 33 and the suction notch 41, the hydraulic oil is efficiently sucked into the pump chamber 6.

The first facing groove 43 and the second facing groove 44 are grooves formed in an arc shape along the circumferential direction. Since the first facing groove 43 communicates with the first discharge port 31 through the pump chamber 6, the pressure of the first facing groove 43 is the same as that of the first discharge port 31. Therefore, the force exerted on the vane 3 by the pressure of the first discharge port 31 is offset by the pressure of the first facing groove 43.

Similarly, since the second facing groove 44 communicates with the second discharge port 32 through the pump chamber 6, the force exerted by the pressure of the second discharge port 32 on the vane 3 is offset by the pressure of the second facing groove 44. By providing the first facing groove 43 and the second facing groove 44 on the cover side side plate 40 in this way, it is possible to prevent the vane 3 from being pressed against the cover side side plate 40.

Further, the body-side side plate 30 and the cover-side side plate 40 are provided with a groove for supplying hydraulic oil to the back pressure chamber 5 and communicating the adjacent back pressure chambers 5.

Specifically, as shown in FIG. 3, the body-side side plate 30 has a first back pressure groove 34 for the suction section and a first back pressure groove for the suction section, which are formed on the sliding contact surface 30a and communicate with the back pressure chamber 5. Open in the first back pressure port 34a that opens in the pressure groove 34, the second back pressure groove 35 for the suction section that is formed on the sliding contact surface 30a and communicates with the back pressure chamber 5, and the second back pressure groove 35 for the suction section. The second back pressure port 35a, the back pressure groove 36 for the first discharge section formed on the sliding contact surface 30a and communicating with the back pressure chamber 5, and the second back pressure groove 36 formed on the sliding contact surface 30a and communicating with the back pressure chamber 5. It has a back pressure groove 37 for a discharge section.

The first back pressure groove 34 for the suction section is a groove formed in an arc shape along the circumferential direction in the portion near the first discharge section DS1 between the through hole 30b and the suction recess 33. The second back pressure groove 35 for the suction section is a groove formed in an arc shape along the circumferential direction in the portion near the second discharge section DS2 between the through hole 30b and the suction recess 33.

One end of the first back pressure port 34a is open to the first back pressure groove 34 for the suction section, and the other end is open to the first high pressure chamber 14. Therefore, the pressure of the first back pressure groove 34 for the suction section is the same as the pressure of the hydraulic oil discharged in the first discharge section DS1.

One end of the second back pressure port 35a is open to the second back pressure groove 35 for the suction section, and the other end is open to the second high pressure chamber 15. Therefore, the pressure of the second back pressure groove 35 for the suction section is the same as the pressure of the hydraulic oil discharged in the second discharge section DS2.

The back pressure groove 36 for the first discharge section is a groove formed in an arc shape along the circumferential direction between the through hole 30b and the first discharge port 31, and the back pressure groove 37 for the second discharge section is It is a groove formed in an arc shape along the circumferential direction between the through hole 30b and the second discharge port 32.

On the other hand, as shown in FIG. 5, the cover-side side plate 40 is formed at a position facing the first back pressure groove 34 for the suction section with the back pressure chamber 5 interposed therebetween. A second back pressure groove 46 formed at a position facing the second back pressure groove 35 for the suction section across the back pressure chamber 5, and a back pressure groove for the first discharge section across the back pressure chamber 5. A third opposed back pressure groove 47 formed at a position facing the 36 and a fourth opposed back pressure groove 48 formed at a position facing the back pressure groove 37 for the second discharge section with the back pressure chamber 5 interposed therebetween. , The first communication groove 45a that communicates the first opposed back pressure groove 45 and the third opposed back pressure groove 47, and the second communication groove that communicates the second opposed back pressure groove 46 and the fourth opposed back pressure groove 48. 46a and.

The first facing back pressure groove 45 is a groove formed in an arc shape along the circumferential direction in a portion near the first facing groove 43 between the through hole 40b and the suction notch 41. The 2 facing back pressure groove 46 is a groove formed in an arc shape along the circumferential direction in a portion near the second facing groove 44 between the through hole 40b and the suction notch 41.

The third facing back pressure groove 47 is a groove formed in an arc shape along the circumferential direction between the through hole 40b and the first facing groove 43, and the fourth facing back pressure groove 48 is a through hole 40b. It is a groove formed in an arc shape along the circumferential direction between the second facing groove 44 and the groove 44.

Since the first facing back pressure groove 45 communicates with the first back pressure groove 34 for the suction section through the back pressure chamber 5, the pressure of the first facing back pressure groove 45 is discharged in the first discharge section DS1. It will be the same as the pressure of the hydraulic oil. Further, the third opposed back pressure groove 47 communicates with the first opposed back pressure groove 45 through the first communication groove 45a, and further, the first back pressure groove 47 is communicated with the third opposed back pressure groove 47 through the back pressure chamber 5. The back pressure groove 36 for the discharge section communicates with the back pressure groove 36. Therefore, the pressures of the third opposed back pressure groove 47 and the back pressure groove 36 for the first discharge section are also substantially the same as the pressure of the hydraulic oil discharged in the first discharge section DS1. Strictly speaking, since the first communication groove 45a functions as a throttle, the first back pressure groove 34 for the suction section and the first facing back pressure groove 34 and the first facing back pressure groove according to the movement of the hydraulic oil due to the expansion / contraction of the volume of the back pressure chamber 5. A pressure difference occurs between the pressure of the pressure groove 45 and the pressure of the back pressure groove 36 for the first discharge section and the pressure of the third opposed back pressure groove 47.

Similarly, since the second opposed back pressure groove 46 communicates with the second back pressure groove 35 for the suction section through the back pressure chamber 5, the pressure of the second opposed back pressure groove 46 is in the second discharge section DS2. It will be the same as the pressure of the discharged hydraulic oil. Further, the fourth opposed back pressure groove 48 communicates with the second opposed back pressure groove 46 through the second communication groove 46a, and further, the second opposed back pressure groove 48 communicates with the second back pressure groove 48 through the back pressure chamber 5. The back pressure groove 37 for the discharge section communicates with the back pressure groove 37. Therefore, the pressures of the fourth opposed back pressure groove 48 and the back pressure groove 37 for the second discharge section are also substantially the same as the pressure of the hydraulic oil discharged in the second discharge section DS2. Strictly speaking, since the second back pressure groove 46a functions as a throttle, the second back pressure groove 35 for the suction section and the second facing back are corresponding to the movement of the hydraulic oil due to the expansion and contraction of the volume of the back pressure chamber 5. A pressure difference occurs between the pressure of the pressure groove 46 and the pressure of the back pressure groove 37 for the second discharge section and the pressure of the fourth opposed back pressure groove 48.

Next, the profile of the inner peripheral cam surface 4a of the cam ring 4 will be described with reference to FIG. FIG. 6 is a profile of the inner peripheral cam surface 4a when the start point R0 of the suction section SS1 is set to zero, and how the amount of protrusion of the vane 3 protruding from the slit 2a while the rotor 2 makes one rotation from the start point R0 is It shows whether it changes to.

As shown in FIG. 6, the inner peripheral cam surface 4a changes so that the vane 3 gradually protrudes from the slit 2a, that is, the volume of the pump chamber 6 gradually expands over the suction section SS1. As the volume of the pump chamber 6 is expanded in this way, the pressure inside the pump chamber 6 becomes negative and the hydraulic oil is sucked into the pump chamber 6.

In the first transition section TS1 following the suction section SS1, the inner peripheral cam surface 4a changes so that the vane 3 slightly enters the slit 2a, that is, the volume of the pump chamber 6 is slightly reduced. By slightly reducing the volume of the pump chamber 6 in this way, the pressure in the pump chamber 6 changes from a negative pressure to a positive pressure.

If the volume of the pump chamber 6 is reduced too much in the first transition section TS1, the pressure in the pump chamber 6 rises excessively, and when the subsequent first discharge section DS1 is reached, a surge pressure may occur. Further, if there is a negative pressure portion in the pump chamber 6 and air bubbles remain, cavitation may occur in the subsequent first discharge section DS1. Therefore, the degree of change of the inner peripheral cam surface 4a in the first transition section TS1 is set to an appropriate magnitude so that bubbles disappear and surge pressure does not occur.

In the first discharge section DS1, the inner peripheral cam surface 4a changes so that the vane 3 enters the slit 2a, that is, the volume of the pump chamber 6 is reduced. By reducing the volume of the pump chamber 6 in this way, the pressure inside the pump chamber 6 becomes positive, and the hydraulic oil is discharged from the pump chamber 6.

In the second transition section TS2 following the first discharge section DS1, the inner peripheral cam surface 4a gently displaces the vane 3 so that the volume change rate of the pump chamber 6 is smaller than that of the first transition section TS1. In the second transition section TS2, the pressure in the pump chamber 6 is already positive and the bubbles are almost eliminated, so that it is not necessary to reduce the volume of the pump chamber 6 as much as in the first transition section TS1. Further, if the volume of the pump chamber 6 is reduced too much, the pressure in the pump chamber 6 rises excessively, and when the subsequent second discharge section DS2 is reached, a surge pressure may occur. Therefore, the degree of change of the inner peripheral cam surface 4a in the second transition section TS2 is set smaller than the degree of change in the first transition section TS1.

In the second discharge section DS2, the inner peripheral cam surface 4a changes so that the vane 3 further enters the slit 2a, that is, the volume of the pump chamber 6 becomes smaller. By further reducing the volume of the pump chamber 6 in this way, hydraulic oil is discharged from the pump chamber 6.

In the third transition section TS3 following the second discharge section DS2, the inner peripheral cam surface 4a gently displaces the vane 3 so that the volume of the pump chamber 6 is minimized. By minimizing the volume of the pump chamber 6 in this way, it becomes possible to smoothly suck the hydraulic oil into the pump chamber 6 in the subsequent suction section SS1.

In order to smoothly suck the hydraulic oil into the pump chamber 6, the length of the suction section SS1 is preferably longer than the total length of the first discharge section DS1 and the second discharge section DS2. ..

Subsequently, the operation of the vane pump 100 having the above configuration will be described.

The rotor 2 rotates in a predetermined direction by rotationally driving the drive shaft 1 by the power of a drive device such as an engine (not shown). As the rotor 2 rotates, the pump chamber 6 moves in the suction section SS1, the first discharge section DS1, and the second discharge section DS2 in this order, and returns to the suction section SS1 again.

In this series of steps, the hydraulic oil is sucked into the pump chamber 6 in the suction section SS1, a part of the sucked hydraulic oil is discharged from the pump chamber 6 in the first discharge section DS1, and is sucked in the second discharge section DS2. The remaining hydraulic oil is discharged from the pump chamber 6. That is, in the vane pump 100, the hydraulic oil is sucked into each pump chamber 6 only once while the rotor 2 makes one rotation, and the hydraulic oil is discharged from each pump chamber 6 twice.

Specifically, when the pump chamber 6 is in the suction section SS1, the volume of the pump chamber 6 gradually increases with the rotation of the rotor 2. Since the pump chamber 6 becomes a negative pressure due to the expansion of the volume of the pump chamber 6, hydraulic oil is sucked into the pump chamber 6 through the suction recess 33 and the suction notch 41 so as to fill the pump chamber 6.

Here, the suction section SS1 provided with the suction port is 1 for the two discharge sections of the first discharge section DS1 provided with the first discharge port 31 and the second discharge section DS2 provided with the second discharge port 32. Only one is provided. Therefore, the suction section SS1 can be lengthened as compared with the case where the suction section is provided for each discharge section as in the conventional balanced vane pump in which two suction sections are provided for the two discharge sections. ..

By lengthening the suction section SS1 in this way, it is possible to sufficiently suck the hydraulic oil into the pump chamber 6 even when the rotation speed of the drive shaft 1 is high.

When the pump chamber 6 moves to the first transition section TS1 following the suction section SS1, the volume of the pump chamber 6 is slightly reduced with the rotation of the rotor 2 so that the pressure of the pump chamber 6 becomes a positive pressure. Further, when the pump chamber 6 moves in the first transition section TS1 by a predetermined distance with the rotation of the rotor 2, the pump chamber 6 eventually becomes the first discharge port 31 and the preceding pump chamber 6 through the first notch 31a. Communicate.

When the pump chamber 6 communicates with the first discharge port 31 and the preceding pump chamber 6 through the first notch 31a, the hydraulic oil pressurized from the first discharge port 31 and the preceding pump chamber 6 passes through the first notch 31a to the pump chamber. Since the pump chamber 6 flows into the pump chamber 6, the pressure in the pump chamber 6 becomes a positive pressure. At this time, if the hydraulic oil in the pump chamber 6 contains air bubbles, the air bubbles become minute and disappear as the pressure in the pump chamber 6 increases. Therefore, the pump chamber 6 and the first discharge port 31 directly communicate with each other, and cavitation is suppressed when the hydraulic oil in the pump chamber 6 is pressurized.

Further, since the first notch 31a has a tapered shape, the pressure of the pump chamber 6 is suppressed by suppressing the sudden inflow of hydraulic oil from the first discharge port 31 and the preceding pump chamber 6 into the pump chamber 6. Is prevented from fluctuating. When a surge pressure is generated in the pump chamber 6, the hydraulic oil gradually flows out to the first discharge port 31 through the first notch 31a, so that the pressure in the pump chamber 6 is stabilized.

When the pump chamber 6 that has passed through the first transition section TS1 moves to the first discharge section DS1, the volume of the pump chamber 6 is predetermined as the rotor 2 rotates so that the hydraulic oil is discharged from the pump chamber 6. Shrink at a rate. The hydraulic oil discharged from the pump chamber 6 is guided to the first high pressure chamber 14 through the first discharge port 31. The hydraulic oil guided to the first high-pressure chamber 14 is supplied to a fluid pressure device provided outside the vane pump 100 through a passage (not shown).

The pressure of the pump chamber 6 that has passed through the first discharge section DS1 and moved to the second transition section TS2 is equivalent to the pressure of the hydraulic oil discharged through the first discharge port 31, and is not a negative pressure, so that the pressure is inside the pump chamber 6. There are almost no bubbles in. That is, since the volume of the pump chamber 6 only needs to be slightly reduced to the extent that the pressure of the pump chamber 6 is maintained in the second transition section TS2, the volume change rate of the pump chamber 6 in the second transition section TS2 is the first. It is possible to make it smaller than the volume change rate of the pump chamber 6 in the transition section TS1.

In particular, if the volume of the pump chamber 6 is significantly changed while the inflow and outflow of hydraulic oil is blocked from the pump chamber 6, the pressure in the pump chamber 6 will fluctuate. On the other hand, by making it possible to reduce the volume change rate of the pump chamber 6 in the second transition section TS2, it is possible to suppress the fluctuation of the pressure in the pump chamber 6 moving in the second transition section TS2. At the same time, the pressure of the hydraulic oil discharged in the subsequent second discharge section DS2 can be stabilized.

Further, when the pump chamber 6 moves in the second transition section TS2 by a predetermined distance with the rotation of the rotor 2, the pump chamber 6 eventually communicates with the second discharge port 32 through the second notch 32a.

When the pump chamber 6 and the second discharge port 32 communicate with each other through the tapered second notch 32a, the hydraulic oil gradually flows into the pump chamber 6 from the second discharge port 32, and the pressure in the pump chamber 6 stabilizes. .. When a surge pressure is generated in the pump chamber 6, the hydraulic oil gradually flows out to the second discharge port 32 through the second notch 32a, so that the pressure in the pump chamber 6 is stabilized.

As described above, since the volume change rate of the pump chamber 6 in the second transition section TS2 is small, the pressure of the pump chamber 6 moved to the second transition section TS2 is the pressure of the pump chamber 6 moved to the first transition section TS1. Not as unstable as the pressure of. Therefore, the second length L2, which is the length of the second notch 32a in the circumferential direction, does not need to be as long as the first length L1 which is the length of the first notch 31a in the circumferential direction. In other words, the size of the cross-sectional area S2 of the second notch 32a at a position separated by a predetermined distance L0 in the circumferential direction from the opening edge of the second discharge port 32 is the circumference from the opening edge of the first discharge port 31. It is not necessary to make it as large as the cross-sectional area S1 of the first notch 31a at a position separated by a predetermined distance L0 in the direction. If the pressure of the pump chamber 6 moved to the second transition section TS2 is stable, the second notch 32a may not be provided.

When the pump chamber 6 that has passed through the second transition section TS2 moves to the second discharge section DS2, the volume of the pump chamber 6 is predetermined as the rotor 2 rotates so that the hydraulic oil is discharged from the pump chamber 6. Shrink at a rate. The hydraulic oil discharged from the pump chamber 6 is guided to the second high pressure chamber 15 through the second discharge port 32. The hydraulic oil guided to the second high-pressure chamber 15 is supplied separately from the hydraulic oil guided to the first high-pressure chamber 14 to a fluid pressure device provided outside the vane pump 100 through a passage (not shown).

When the pump chamber 6 that has passed through the second discharge section DS2 moves to the third transition section TS3, the volume of the pump chamber 6 is reduced by a predetermined ratio so that the volume of the pump chamber 6 is minimized. In this way, by minimizing the volume of the pump chamber 6 before reaching the suction section SS1, the hydraulic oil can be efficiently sucked in the suction section SS1.

In this way, the vane pump 100 sucks the hydraulic oil into the pump chamber 6 in one suction section SS1 and discharges the hydraulic oil from the pump chamber 6 in the two discharge sections DS1 and DS2. Therefore, it is possible to simultaneously supply the low-pressure hydraulic oil and the high-pressure hydraulic oil to the fluid pressure device provided outside.

When supplying low-pressure hydraulic oil and high-pressure hydraulic oil to the fluid pressure device at the same time, the second discharge port 32 in the second discharge section DS2 where the hydraulic oil pressurized in the first discharge section DS1 can be further pressurized. The hydraulic oil discharged through is supplied to the fluid pressure device as high pressure hydraulic oil, and the hydraulic oil discharged through the first discharge port 31 in the first discharge section DS1 is supplied as low pressure hydraulic oil.

The hydraulic oil discharged through the second discharge port 32 may be supplied as low pressure hydraulic oil, and the hydraulic oil discharged through the first discharge port 31 may be supplied as high pressure hydraulic oil to the fluid pressure device. When supplying hydraulic oil of a single pressure to the fluid pressure device, the hydraulic oil discharged through the second discharge port 32 and the hydraulic oil discharged through the first discharge port 31 are merged and the fluid pressure device is used. Is supplied to.

Further, while the vane pump 100 is being driven as described above, the back pressure chamber 5 on the first discharge section DS1 side of the back pressure chamber 5 in the suction section SS1 and the first discharge from the first transition section TS1. The back pressure chamber 5 in the section DS1 is supplied with the hydraulic oil discharged from the pump chamber 6 in the first discharge section DS1 through the first back pressure port 34a, and the back pressure chamber 5 in the suction section SS1. Of these, the back pressure chamber 5 on the second discharge section DS2 side and the back pressure chamber 5 in the second discharge section DS2 from the second transition section TS2 were discharged from the pump chamber 6 in the second discharge section DS2. Hydraulic oil is supplied through the second back pressure port 35a.

By making the pressure of the hydraulic oil supplied to the back pressure chamber 5 different in this way, for example, when the pressure of the hydraulic oil discharged from the pump chamber 6 in the first discharge section DS1 becomes low pressure, Since the pressure in the back pressure chamber 5 to which the hydraulic oil is supplied through the first back pressure port 34a is also low, the relatively high pressure hydraulic oil discharged from the pump chamber 6 in the second discharge section DS2 is used in all the back pressure chambers. As compared with the case where the vane 3 is supplied to the back pressure chamber 5, the force with which the vane 3 is pressed against the inner peripheral cam surface 4a of the cam ring 4 is reduced by the pressure of the back pressure chamber 5. As a result, the frictional force generated between the vane 3 and the inner peripheral cam surface 4a is reduced, and as a result, the torque for driving the vane pump 100 can be reduced.

Further, in the vane pump 100 having the above configuration, there is one suction section SS1 in which the hydraulic oil is sucked into the pump chamber 6, and two discharge sections DS1 and DS2 in which the hydraulic oil is discharged from the pump chamber 6, which are transitions. There are three sections TS1, TS2, and TS3. Therefore, as compared with the balanced vane pump having two suction sections and two discharge sections, the number of suction sections and the number of transition sections are reduced by one, so that the suction sections SS1 and the discharge sections DS1 and DS2 are used. It can be lengthened.

Therefore, for example, by lengthening the suction section SS1, the hydraulic oil can be sufficiently sucked into the pump chamber 6, and as a result, the pump efficiency can be improved. Further, by lengthening the discharge sections DS1 and DS2, the pressure of the hydraulic oil discharged from the pump chamber 6 can be stabilized.

According to the above embodiment, the following effects are obtained.

In the vane pump 100 according to the above embodiment, three ports, a suction port (suction recess 33, a suction notch 41), a first discharge port 31 and a second discharge port 32, are formed along the rotation direction of the rotor 2. They are arranged in this order. That is, the hydraulic oil sucked in by one suction port is first discharged through the first discharge port 31 and then discharged through the second discharge port 32. By making one suction port for the two discharge ports 31 and 32 in this way, the suction period for sucking the hydraulic oil becomes longer, so that the hydraulic oil can be sufficiently sucked and the operation is performed. Since the period from the suction of the oil to the discharge is long, it is possible to discharge the sufficiently boosted hydraulic oil through the discharge ports 31 and 32. As described above, in the vane pump 100 according to the above embodiment, insufficient suction of hydraulic oil and insufficient step-up are eliminated, and as a result, fluctuations in the discharge pressure of the vane pump 100 can be suppressed.

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

The vane pump 100 includes a rotor 2 that is rotationally driven, a plurality of vanes 3 that are slidably inserted into a plurality of slits 2a formed radially in the rotor 2, and a tip portion 3a of the vane 3 as the rotor 2 rotates. Guides the pump chamber 6 defined between the cam ring 4 having the inner peripheral cam surface 4a in sliding contact with the cam ring 4, the adjacent vanes 3, the rotor 2, and the cam ring 4, and the hydraulic oil sucked into the pump chamber 6. It is provided with a suction port (suction recess 33, suction notch 41), a first discharge port 31 and a second discharge port 32 for guiding hydraulic oil discharged from the pump chamber 6, and the suction ports 33, 41, and the first. The 1 discharge port 31 and the 2nd discharge port 32 are arranged in this order along the rotation direction of the rotor 2.

In this configuration, the three ports of the suction ports 33 and 41, the first discharge port 31 and the second discharge port 32 are arranged in this order along the rotation direction of the rotor 2. That is, the hydraulic oil sucked in by one suction port 33, 41 is first discharged through the first discharge port 31, and then discharged through the second discharge port 32. By making the suction ports 33 and 41 one for the two discharge ports 31 and 32 in this way, the suction period for sucking the hydraulic oil becomes longer, so that the hydraulic oil can be sufficiently sucked. Further, since the period from the suction of the hydraulic oil to the discharge is long, it is possible to discharge the sufficiently boosted hydraulic oil through the discharge ports 31 and 32. As described above, in the vane pump 100 having the above configuration, insufficient suction of hydraulic oil and insufficient boosting are eliminated, and as a result, fluctuations in the discharge pressure of the vane pump 100 can be suppressed.

Further, in this configuration, the hydraulic oil is discharged from the two discharge ports of the first discharge port 31 and the second discharge port 32. Therefore, it is possible to supply two stable pressures with little fluctuation to a fluid pressure device that requires hydraulic oils of different pressures.

Further, the volume of the pump chamber 6 expands with the rotation of the rotor 2 in the suction section SS1 in which the suction ports 33 and 41 and the pump chamber 6 communicate with each other, and the first discharge port 31 and the pump chamber 6 following the suction section SS1 are expanded. Rotates the rotor 2 in the second discharge section DS2 in which the second discharge port 32 following the first discharge section DS1 and the pump chamber 6 communicate with each other. As a result, it further shrinks and expands again in the suction section SS1 following the second discharge section DS.

In this configuration, the hydraulic oil sucked in one suction section SS1 is first discharged in the first discharge section DS1 and then discharged in the second discharge section DS2. In this way, by making the suction section SS1 one for the two discharge sections DS1 and DS2, the suction period for sucking the hydraulic oil becomes longer, so that the hydraulic oil can be sufficiently sucked, and the hydraulic oil can be sufficiently sucked. Since the period from the suction of the hydraulic oil to the discharge is long, it is possible to discharge the sufficiently boosted hydraulic oil in each discharge section DS1 and DS2. As described above, in the vane pump 100 having the above configuration, insufficient suction of hydraulic oil and insufficient boosting are eliminated, and as a result, fluctuations in the discharge pressure of the vane pump 100 can be suppressed.

Further, a first transition section TS1 in which the pump chamber 6 is closed is provided between the suction section SS1 and the first discharge section DS1, and a pump chamber is provided between the first discharge section DS1 and the second discharge section DS2. A second transition section TS2 in which 6 is closed is provided, and the volume change rate of the pump chamber 6 in the second transition section TS2 is smaller than the volume change rate of the pump chamber 6 in the first transition section TS1.

In this configuration, the volume change rate of the pump chamber 6 in the second transition section TS2 is set to be smaller than the volume change rate of the pump chamber 6 in the first transition section TS1. By reducing the volume change rate of the pump chamber 6 in the second transition section TS2 in this way, it is possible to suppress fluctuations in the pressure in the pump chamber 6 moving in the second transition section TS2, especially the occurrence of surge pressure. At the same time, the pressure of the hydraulic oil discharged in the subsequent second discharge section DS2 can be stabilized. As a result, it is possible to supply hydraulic oil with a stable pressure with small pressure fluctuation to the fluid pressure device.

Further, the vane pump 100 further includes a back pressure chamber 5 partitioned by a base end portion 3b of the vane 3 in the slit 2a, and is a back pressure chamber 5 on the first discharge section DS1 side of the back pressure chamber 5 in the suction section SS1. The hydraulic oil discharged through the first discharge port 31 is guided to the pressure chamber 5, and the back pressure chamber 5 on the second discharge section DS2 side of the back pressure chamber 5 in the suction section SS1 has a second. The hydraulic oil discharged through the discharge port 32 is guided.

In this configuration, the hydraulic oil discharged through the first discharge port 31 is guided to the back pressure chamber 5 on the first discharge section DS1 side of the back pressure chamber 5 in the suction section SS1 and is inside the suction section SS1. The hydraulic oil discharged through the second discharge port 32 is guided to the back pressure chamber 5 on the second discharge section DS2 side of the back pressure chamber 5 in the above. Therefore, when the pressure of the hydraulic oil discharged through the first discharge port 31 becomes low, the back pressure chamber 5 on the first discharge section DS1 side of the back pressure chamber 5 in the suction section SS1. Since the pressure is also low, the force with which the vane 3 is pressed against the inner peripheral cam surface 4a of the cam ring 4 by the pressure of the back pressure chamber 5 is reduced. As a result, the frictional force generated between the vane 3 and the inner peripheral cam surface 4a is reduced, and as a result, the torque for driving the vane pump 100 can be reduced.

Further, the vane pump 100 has a first notch 31a extending in a direction opposite to the rotation direction of the rotor 2 from the opening edge portion of the first discharge port 31, and a rotation direction of the rotor 2 from the opening edge portion of the second discharge port 32. Further comprises a second notch 32a extending in the opposite direction, the first length L1 which is the circumferential length of the first notch 31a is the second length which is the circumferential length of the second notch 32a. It is longer than L2.

In this configuration, the first length L1 which is the length of the first notch 31a in the circumferential direction is set longer than the second length L2 which is the length of the second notch 32a in the circumferential direction. In this way, by lengthening the first notch 31a, the pressure of the pump chamber 6 reaches the pressure of the pump chamber 6 in the first transition section TS1 where the pressure of the pump chamber 6 becomes relatively unstable, and the pump chamber 6 reaches the first discharge section DS1. It is possible to stabilize before, and as a result, the pressure of the hydraulic oil discharged through the first discharge port 31 can be stabilized.

Further, in this configuration, by shortening the length of the second notch 32a provided in the second transition section TS2 where the pressure of the pump chamber 6 is relatively stable, the pump chamber is transmitted from the second discharge port 32 through the second notch 32a. It is possible to suppress the inflow of hydraulic oil into 6 and prevent the pressure of the second discharge port 32 from dropping, and as a result, stabilize the pressure of the hydraulic oil discharged through the second discharge port 32. Can be done.

Further, the vane pump 100 has a first notch 31a extending in a direction opposite to the rotation direction of the rotor 2 from the opening edge portion of the first discharge port 31, and a rotation direction of the rotor 2 from the opening edge portion of the second discharge port 32. Further comprises a second notch 32a extending in the opposite direction, and the cross-sectional area S1 of the first notch 31a at a position separated by a predetermined distance L0 in the circumferential direction from the opening edge of the first discharge port 31 is a second. It is larger than the cross-sectional area S2 of the second notch 32a at a position separated by a predetermined distance L0 in the circumferential direction from the opening edge of the discharge port 32.

In this configuration, the cross-sectional area S1 of the first notch 31a at a position separated by a predetermined distance L0 in the circumferential direction from the opening edge portion of the first discharge port 31 is predetermined in the circumferential direction from the opening edge portion of the second discharge port 32. It is set to be larger than the cross-sectional area S2 of the second notch 32a at a position separated by the distance L0. In this way, by increasing the cross-sectional area S1 of the first notch 31a, the pressure of the pump chamber 6 is discharged by the pump chamber 6 in the first transition section TS1 in which the pressure of the pump chamber 6 becomes relatively unstable. It becomes possible to stabilize before reaching the section DS1, and as a result, the pressure of the hydraulic oil discharged through the first discharge port 31 can be stabilized.

Further, in this configuration, by reducing the cross-sectional area S2 of the second notch 32a provided in the second transition section TS2 where the pressure of the pump chamber 6 is relatively stable, the pump is pumped from the second discharge port 32 through the second notch 32a. It is possible to suppress the inflow of hydraulic oil into the chamber 6 and prevent the pressure of the second discharge port 32 from dropping, and as a result, stabilize the pressure of the hydraulic oil discharged through the second discharge port 32. be able to.

Further, the pressure of the hydraulic oil discharged through the second discharge port 32 is higher than the pressure of the hydraulic oil discharged through the first discharge port 31.

In this configuration, the pressure of the hydraulic oil discharged through the second discharge port 32 is higher than the pressure of the hydraulic oil discharged through the first discharge port 31. In this way, even if there is only one suction port 33, 41, a relatively low pressure hydraulic oil is supplied from the first discharge port 31, and a relatively high pressure hydraulic oil is supplied from the second discharge port 32. , It is possible to supply two stable pressures with little fluctuation to fluid pressure equipment that requires hydraulic fluid of different pressures.

Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiments. do not have.

For example, the vane pump 100 is not limited to a pump having a constant discharge capacity (pump push-out volume), and may be a variable capacity type pump in which the discharge capacity can be changed by displacing the cam ring.

100 ... vane pump, 1 ... drive shaft, 2 ... rotor, 2a ... slit, 3 ... vane, 3a ... tip, 3b ... base end, 4 ... Cam ring, 4a ... Inner circumference cam surface, 5 ... Back pressure chamber, 6 ... Pump chamber, 10 ... Pump body, 14 ... First high pressure chamber, 15 ... Second high pressure chamber , 20 ... Pump cover, 21 ... Suction pressure chamber, 30 ... Body side side plate, 31 ... First discharge port, 31a ... First notch, 32 ... Second discharge port , 32a ... 2nd notch, 33 ... suction recess (suction port), 40 ... cover side side plate, 41 ... suction notch (suction port), SS1 ... suction section, DS1 ... 1st discharge section, DS2 ... 2nd discharge section, TS1 ... 1st transition section, TS2 ... 2nd transition section, TS3 ... 3rd transition section

Claims (7)

It ’s a vane pump.
Rotationally driven rotor and
A plurality of vanes slidably inserted into a plurality of slits formed radially in the rotor, and a plurality of vanes.
A cam ring having an inner cam surface with which the tip of the vane is in sliding contact with the rotation of the rotor.
A pump chamber defined between the adjacent vanes, the rotor, and the cam ring.
A suction port that guides the working fluid sucked into the pump chamber,
A first discharge port and a second discharge port for guiding the working fluid discharged from the pump chamber are provided.
The suction port, the first discharge port, and the second discharge port are arranged in this order along the rotation direction of the rotor .
The length of the suction section in which the suction port and the pump chamber communicate is the length of the first discharge section in which the first discharge port and the pump chamber communicate with each other, and the second discharge port and the pump chamber communicate with each other. A vane pump characterized in that it is set to a length equal to or greater than the length of the second discharge section . The volume of the pump chamber expands with the rotation of the rotor in the suction section where the suction port and the pump chamber communicate with each other, and the first discharge port following the suction section and the pump chamber communicate with each other. In the first discharge section, the volume is reduced with the rotation of the rotor, and further with the rotation of the rotor in the second discharge section in which the second discharge port following the first discharge section and the pump chamber communicate with each other. The vane pump according to claim 1, wherein the vane pump is reduced in size and expanded again in the suction section following the second discharge section. A first transition section in which the pump chamber is closed is provided between the suction section and the first discharge section.
A second transition section in which the pump chamber is closed is provided between the first discharge section and the second discharge section.
The vane pump according to claim 2, wherein the volume change rate of the pump chamber in the second transition section is smaller than the volume change rate of the pump chamber in the first transition section. Further comprising a back pressure chamber partitioned by the proximal end of the vane in the slit.
Of the back pressure chambers in the suction section, the working fluid discharged through the first discharge port is guided to the back pressure chamber on the first discharge section side.
2. The vane pump according to 3. A first notch extending from the opening edge of the first discharge port in a direction opposite to the rotation direction of the rotor,
Further, a second notch extending from the opening edge of the second discharge port in a direction opposite to the rotation direction of the rotor is provided.
The vane pump according to any one of claims 1 to 4, wherein the length of the first notch in the circumferential direction is longer than the length of the second notch in the circumferential direction. A first notch extending from the opening edge of the first discharge port in a direction opposite to the rotation direction of the rotor,
Further, a second notch extending from the opening edge of the second discharge port in a direction opposite to the rotation direction of the rotor is provided.
The cross-sectional area of the first notch at a position separated by a predetermined distance in the circumferential direction from the opening edge of the first discharge port is a position separated by the predetermined distance in the circumferential direction from the opening edge of the second discharge port. The vane pump according to any one of claims 1 to 4, wherein the vane pump is larger than the cross-sectional area of the second notch in the above. The vane pump according to any one of claims 1 to 6, wherein the pressure of the working fluid discharged through the second discharge port is higher than the pressure of the working fluid discharged through the first discharge port. ..

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