JP3759658B2 - Vane pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vane pump that supplies oil, and more particularly, to a vane pump that adjusts discharged pressurized oil by a flow control device and then returns the excess oil to the suction side of the vane pump.
[0002]
[Prior art]
Various vane pumps of this type have been proposed in the past, and an example described in Japanese Patent Publication No. Sho 62-2318 is shown in FIG.
A pressing plate 02, a side plate 03, and a cam ring 04 are accommodated in this order in the pump housing 01, and a rotor 05 in which vanes are radially fitted into and out of the cam ring 04 is fitted. Is covered with a lid member 07, and a rotating shaft 08 pivotally supported by the lid member 07 is fitted in the center of the rotor 05.
[0003]
Suction ports 011 and 012 are formed on both sides of the cam ring 04 so as to face each other, and a communication oil passage 013 communicates between the suction ports 011 and 012.
One suction port 011 is formed at two locations on the side plate 03, and a suction oil passage 014 is formed in the pressing plate 02 that branches from and communicates with the two suction ports 011 and 011. The suction port 011 communicates with the central branch portion in the axial direction. A suction oil passage 015 is formed in the pump housing 01, and a replenishment oil passage 016 extending from an oil tank (not shown) communicates with the suction oil passage 015.
[0004]
The pressure chamber 017 on the back side of the pressing plate communicates with a discharge port (not shown), and the pressure oil discharged to the pressure chamber 017 is supplied to a required location via a throttle member (not shown).
A circular hole 018 is formed on the opposite side of the pump chamber of the pump housing 01 to the suction oil passage 015, and a spool valve 019 is slidably fitted into the circular hole 018 closed at both ends.
[0005]
A bypass oil passage 020 extending from the pressure chamber 017 communicates with one end space of the circular hole 018.
The spool valve 019 is biased by a spring 021. When the discharge side hydraulic pressure in the pressure chamber 017 exceeds a predetermined pressure, the spool valve 019 slides against the spring 021 and sucks into the bypass oil passage 020. Communicate with oil passage 015.
[0006]
Therefore, when the pump rotation speed increases, the discharge flow rate increases, and the hydraulic pressure in the pressure chamber 017 exceeds the predetermined pressure, the spool valve 019 is slid to connect the bypass oil passage 020 and the suction oil passage 015 to suck in excess oil. The oil flows back to the oil passages 015 and 014, and operates so as to make the pressure difference before and after the throttle portion of the discharge flow constant.
[0007]
In addition to the above examples, examples described in Japanese Utility Model Publication No. 4-29111 and Japanese Patent Application Laid-Open No. Sho 62-35087 have substantially the same structure, and surplus oil joins the intake oil passage in the same manner as the above example. To do.
[0008]
[Problems to be solved by the invention]
The suction oil passage 014 communicates with one suction port 011 of the suction ports 011 and 012 on both sides of the cam ring 04. First, most of the hydraulic oil is introduced into the suction port 011 and is passed from the suction port 011 to the suction side pump chamber. Inhaled.
A part of the hydraulic oil that bypasses the communication oil path 013 from the suction port 011 side is reduced in flow velocity due to the bypass and reaches a pressure of the other suction port 012 and is sucked into the suction side pump chamber from the suction port 012. The
[0009]
Therefore, the hydraulic pressure of the downstream suction port 012 is lower than the hydraulic pressure of the upstream suction port 011. The oil pressure balance between the suction ports 011 and 012 on both sides of the suction side pump chamber is not obtained, and the suction efficiency is good. Absent.
The surplus oil that recirculates from the discharge side merges with the hydraulic oil in the suction oil passage 015, and therefore does not affect the oil pressure balance between the suction ports 011 and 012.
[0010]
In addition, in the suction oil passage 015 where the surplus oil merges with the hydraulic oil, the flow resistance changes drastically and cavitation and noise may be induced due to pulsation or the like.
The present invention has been made in view of the above points, and the object of the present invention is to obtain an oil pressure balance between the suction ports on both sides of the suction side pump chamber by using the excess oil that is refluxed, and to achieve excellent suction efficiency. The point is to provide a vane pump.
[0011]
[Means for solving the problems and effects]
In order to achieve the above object, according to the present invention, a communication oil passage that goes around the outside of the cam ring communicates between two suction ports formed on both sides of the cam ring of the vane pump, and the suction oil passage is connected to the one suction port. The vane pump was opened and communicated, and a return oil passage for recirculating surplus oil from the flow control device opened and communicated with the other suction port.
[0012]
One of the intake ports is connected to the intake oil passage so that most of the hydraulic oil flows directly into the other intake port, and a part of the hydraulic oil flows into the other intake port through the communication passage, resulting in a low pressure. Since the oil passage opens and the surplus oil is directly introduced, the oil pressure can be increased, the oil pressure balance between the suction ports on both sides of the suction side pump chamber can be obtained, and the suction efficiency is improved. be able to.
[0013]
Further, since the surplus oil merges with part of the hydraulic oil, there is no drastic change in flow resistance, and there is no possibility of inducing cavitation or abnormal noise due to pulsation or the like.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
A front view of the vane pump 1 of the present embodiment is shown in FIG.
In the vane pump 1, a cover 10 covers the front opening of the pump housing 2, and a front view with the cover 10 removed is shown in FIG. 2, a front view of the cover 10 itself is shown in FIG. 3, and a front view of the pump housing 2 itself is shown. Is shown in FIG. 4 and FIG.
[0015]
As shown in FIGS. 4 and 5, the front of the front portion of the pump housing 2 is formed with an opening of a circular hole 3, and the periphery of the circular opening becomes a mating surface 2a with the cover 10, so that there are five mating surfaces 2a. Bolt screw holes 2b are provided at the locations.
The rear portion of the pump housing 2 has a bulging portion 2c bulging to the right in the front view, the rear surface 2d forms a flat surface, and a bolt hole 2e is drilled at a predetermined peripheral edge.
[0016]
Predetermined portions of the inner peripheral surface of the circular hole 3 facing each other are cut out in an arc shape to form the communication oil passages 4, 4, and the back side of each communication oil passage 4, 4 is made a half circumference along the inner peripheral surface The return oil passage 5 communicates, and the return oil passage 5 extends obliquely above the bulging portion 2c from the intermediate portion and opens on the rear surface 2d (see the hatched portion in FIG. 4 and FIG. 11).
A cylindrical portion 7 through which the drive shaft 35 passes is formed at the center of the bottom surface of the circular hole 3, and an annular bottom surface around the cylindrical portion 7 forms a pressure chamber 8, and a bulging portion 2 c from a part of the pressure chamber 8. The discharge oil passage 9 extends to the right side of the opening and opens on the rear surface 2d (see the hatched portion in FIG. 5 and FIG. 12).
[0017]
The cover 10 covering the front opening of the pump housing 2 has a mating surface on the rear surface corresponding to the mating surface 2a of the pump housing 2, and a bolt hole 10b corresponding to the bolt screw hole 2b on the peripheral edge. (See FIG. 3).
A circular hole 11 that pivotally supports the drive shaft 35 is formed in the center of the cover 10, and a circular suction port 12 is formed at the position eccentric to the right of the circular hole 11 so as to open to the front. The suction oil passage 13 extends in a circular arc shape from the bottom of 12 and extends along the back surface. The suction ports 14, 14 are formed at positions corresponding to the pair of communication oil passages 4, 4 of the pump housing 2. And open on the back surface of the cover 10 (see the dotted pattern in FIG. 3).
[0018]
A side plate 20 and a cam ring 40 are sequentially fitted in the circular hole 3 of the pump housing 2, a rotor 30 is disposed in an inner peripheral cam surface 41 of the cam ring 40, and a drive shaft 35 penetrating the cylindrical portion 7 is a rotor. Fits 30 and rotates together.
As shown in FIG. 8, the rotor 30 is formed with a circular hole 31 into which the drive shaft 35 is fitted, and a plurality of vane grooves 32 are formed radially around the rotor 30. A vane back pressure chamber 33 is formed, and a vane 34 is fitted in the vane groove 32 so as to be able to appear and retract.
[0019]
As shown in FIG. 6, the side plate 20 has a disk shape, and a circular hole 21 that fits into the cylindrical portion 7 is formed in the center, and a vane back pressure chamber at the bottom of the vane groove 32 of the rotor 30 is formed around the side plate 20. A through hole 22 for introducing pressure oil and a recess 23 are formed in 33, and suction ports 24, 24 and discharge ports 25, 25 are formed around the through hole 22 and the recess 23 in pairs and facing each other. ing.
The suction ports 24, 24 are concave portions cut out to the outer peripheral surface, and the discharge ports 25, 25 are arc-shaped through holes.
[0020]
On the other hand, in the cam ring 40, as shown in FIG. 7, the rotor 30 is rotatably fitted to a substantially elliptical inner cam surface 41, and the tip of the vane 34 fitted in the vane groove 32 of the rotor 30 is the inner circumference. A pump chamber is formed in contact with the cam surface 41.
A pair of suction recesses 42, 42 are formed symmetrically on the front surface of the cam ring 40, and suction recesses 43, 43 are formed on the rear surface opposite to the suction recesses 42, 42 (see FIG. 10).
Further, a pair of discharge communication oil passages 44 are formed at different angular positions of the cam ring 40.
[0021]
The above members are assembled by first fitting the side plate 20 and the cam ring 40 into the circular hole 3 of the pump housing 2 in a predetermined positional relationship, and the rotor 33 with the drive shaft 35 fitted together with the vane 34 and the cam ring 40. The drive shaft 35 is fitted into the cylindrical portion 7 by being fitted in the inner peripheral cam surface 41.
Then, the cover 10 is put on the front opening of the pump housing 2, the protruding end of the drive shaft 35 is fitted to the circular hole 11, and the bolt 50 is passed through the bolt hole 10b and screwed into the bolt screw hole 2b to be tightened. To do.
[0022]
A drive shaft 35 protruding from the rear surface of the pump housing 2 is driven by a drive source such as an internal combustion engine (not shown), and the rotor 30 is rotated integrally with the drive shaft 35.
Oil from the oil tank is sucked into the suction port 12 of the cover 10, pressure oil is sent from the rear opening of the discharge oil passage 9 of the pump housing 2 to the regulator valve, and the pressure is adjusted from the regulator valve so that the oil is applied to the required location. Supplied.
The discharged oil returns to the return oil passage 5 from the rear opening of the pump housing 2 through a lubrication valve that adjusts the hydraulic pressure so as not to be too high.
[0023]
As shown in FIG. 10, the cover-side suction port 14 and the back-side suction port 24 are positioned so as to correspond to the front and rear suction recesses 42 and 43 of the cam ring 40, and the communication oil passage 4 is connected to both the suction ports 14 and 24. The outside of the cam ring 40 is bypassed and communicated.
The oil passage 5 opens and communicates with the back side of the communication oil passage 4 and the back side suction port 24.
[0024]
Accordingly, the rotor 30 rotates and the working oil sucked directly from the cover side suction port 14 into the suction pump chamber through the suction oil passage 13 and the cover side suction port 14 is divided into the communication oil passage 4 and detoured to the back side. There is working oil sucked into the suction pump chamber from the port 24, and surplus oil is further returned from the return oil passage 5 to the back suction port 24 and sucked into the suction pump chamber.
[0025]
The cover side suction port 14 is high in pressure because the hydraulic oil enters directly from the suction oil passage 13, and the back side suction port 24 is low in pressure because a part of the hydraulic oil enters the communication oil passage 4 and the flow velocity decreases. However, in the vane pump 1, surplus oil flows directly into the back side suction port 24 to increase the hydraulic pressure.
[0026]
Accordingly, the suction efficiency can be improved by balancing the pressures of the suction ports 14 and 24 before and after the suction pump chamber.
Further, since the surplus oil joins part of the hydraulic oil that bypasses the communication oil passage 4, there is no drastic change in flow resistance and there is no possibility of inducing cavitation or abnormal noise due to pulsation or the like.
[0027]
As shown in FIG. 11, pressure oil is discharged from the discharge-side pump chamber to both the front and rear sides, the rear (back side) is directly discharged to the discharge port 25, and the pressure oil discharged to the front is formed on the rear surface of the cover 10. The discharge groove 25 bypasses the discharge communication oil passage 44 of the cam ring 40 and joins the discharge port 25.
Pressure oil is supplied from the discharge port 25 through the pressure chamber 8 and the discharge oil passage 9 (see FIG. 12).
[0028]
A part of the pressure oil discharged into the pressure chamber 8 enters the vane back pressure chamber 33 at the bottom of the vane groove 32 of the rotor 30 through the through hole 22 of the side plate 20 (see FIG. 10). Energizing in the centrifugal direction, the tip of the vane 34 is always in contact with the inner peripheral cam surface 41 of the cam ring 40.
[Brief description of the drawings]
FIG. 1 is a front view of a vane pump according to an embodiment of the present invention.
FIG. 2 is a front view showing a state where a cover of the vane pump is removed.
FIG. 3 is a front view of a cover.
FIG. 4 is a front view showing a return oil passage of the pump housing.
FIG. 5 is a front view showing a discharge oil passage of a pump housing.
FIG. 6 is a front view of a side plate.
FIG. 7 is a front view of the cam ring.
FIG. 8 is a front view of the rotor.
FIG. 9 is a partially omitted front view showing an assembled state of the vane pump.
10 is a cross-sectional view taken along line XX in FIG.
11 is a cross-sectional view taken along line XI-XI in FIG.
12 is a cross-sectional view taken along line XII-XII in FIG.
FIG. 13 is a cross-sectional view of a vane pump shown with a conventional spool valve.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Vane pump, 2 ... Pump housing, 3 ... Circular hole, 4 ... Communication oil path, 5 ... Return oil path, 7 ... Cylindrical part, 8 ... Pressure chamber, 9 ... Discharge oil path,
10 ... cover, 11 ... circular hole, 12 ... suction port, 13 ... suction oil passage, 14 ... suction port,
20 ... side plate, 21 ... circular hole, 22 ... through hole, 23 ... recess, 24 ... suction port, 25 ... discharge port,
30 ... rotor, 31 ... round hole, 32 ... vane groove, 33 ... vane back pressure chamber, 34 ... vane,
40 ... Cam ring, 41 ... Cam surface, 42, 43 ... Suction recess, 44 ... Discharge communication oil passage,
50 ... Bolt.

Claims (1)

A communication oil passage that goes around the outside of the cam ring communicates between two suction ports formed on both side surfaces of the cam ring of the vane pump,
An intake oil passage opens and communicates with the one intake port,
A vane pump characterized in that a return oil passage for returning excess oil from the flow rate control device opens and communicates with the other suction port.

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