JP2009052525A - Vane pump - Google Patents

Abstract

An object of the present invention is to provide a vane pump having good suction characteristics even in a large discharge capacity vane pump.
A rotor connected to a drive shaft, a plurality of vanes provided so as to be capable of reciprocating in a radial direction with respect to the rotor, and a rotor that accommodates the rotor 2 and has an inner circumference as the rotor rotates. A cam ring 4 on which the tip of the vane 3 slides on the cam surface 4 a and a pair of sides that define a pump chamber 7 between the rotor 2 and the cam ring 4. The suction ports 8 and 9 that are formed in the part members 5 and 6 and the pair of side members 5 and 6, respectively, lead the working fluid to the pump chamber 7, and bypass the cam ring 4. The communication passage 17 is connected to the cam ring 4, and the suction passage port 20 is formed through the cam ring 4 to guide the working fluid from the communication passage 17 to the pump chamber 7.
[Selection] Figure 1

Description

  The present invention relates to a vane pump used as a hydraulic pressure supply source of a power steering device for a vehicle, for example.

  As a conventional vane pump, in FIG. 22 of Patent Document 1, a suction port is formed on the side surface of the side plate and an inflow defect portion is formed on the side surface of the cam ring, and hydraulic fluid is pumped by the suction port and the inflow defect portion. What flows into the chamber is disclosed.

The vane pump disclosed in Patent Document 1 increases the flow area of the suction port in order to facilitate the inflow of hydraulic oil into the pump chamber.
JP-A-9-88846

  However, even in the case of a vane pump having a large suction port flow area as in Patent Document 1, in the case of a vane pump having a large discharge capacity, the cam ring is thick, so that the hydraulic oil is sufficiently supplied to the center of the pump chamber. There was a problem that it was difficult to get around.

  In particular, as the engine rotates at a higher speed, the time required for the pump chamber to communicate with the suction port is shortened, so that the suction characteristic of the hydraulic oil is degraded.

  If the suction characteristics are deteriorated and the hydraulic oil does not reach the center of the pump chamber sufficiently, there is a risk of equipment damage due to cavitation, seizure due to insufficient lubrication of the sliding portion of the vane, and the like.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a vane pump having good suction characteristics even in a large discharge capacity vane pump.

  The present invention relates to a rotor coupled to a drive shaft, a plurality of vanes provided so as to be capable of reciprocating in the radial direction with respect to the rotor, and a cam on the inner circumference as the rotor is accommodated. A cam ring on which a tip of the vane slides on a surface, a pair of side members disposed between both sides of the rotor and the cam ring, and defining a pump chamber between the rotor and the cam ring; A suction port formed in each of the pair of side members and guiding the working fluid to the pump chamber; a communication passage formed around the cam ring and connecting the suction ports of the pair of side members; and the cam ring And a suction penetrating port that leads the working fluid from the communication passage to the pump chamber.

  According to the present invention, in addition to the suction port formed in each of the pair of side members, the suction through port formed through the cam ring is also provided. However, the hydraulic oil is sufficiently distributed to the center of the pump chamber through the suction through port, and the suction characteristics are improved.

  Embodiments of the present invention will be described below with reference to the drawings.

  Below, the case where the vane pump of this invention is applied to the hydraulic pressure supply source of the power steering apparatus mounted in a vehicle is demonstrated.

  A vane pump 100 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing a cross section parallel to the drive shaft in the vane pump 100.

  In the vane pump 100, the power of an engine (not shown) is transmitted to the drive shaft 1, and the rotor 2 connected to the drive shaft 1 rotates.

  The vane pump 100 accommodates the plurality of vanes 3 provided so as to be capable of reciprocating in the radial direction with respect to the rotor 2 and the tip of the vane 3 on the inner cam surface 4 a as the rotor 2 rotates. And a sliding cam ring 4.

  A pump cover 5 is disposed on one side (left side in FIG. 1) of the rotor 2 and the cam ring 4, and a side plate 6 is disposed on the other side (right side in FIG. 1). Thus, the pump cover 5 and the side plate 6 (a pair of side members) are arranged with the both sides of the rotor 2 and the cam ring 4 sandwiched therebetween. Thereby, a pump chamber 7 partitioned by the vanes 3 is defined between the rotor 2 and the cam ring 4.

  The cam ring 4 is an annular member having an inner circumferential cam surface 4 a having an elliptical shape, and a suction region that extends between the vanes 3 that slide on the cam surface 4 a as the rotor 2 rotates, and between the vanes 3. And a discharge region that contracts. The pump chamber 7 sucks the working oil (working fluid) in the suction area and discharges the working oil in the discharge area. In the present embodiment, the cam ring 4 has two suction areas and two discharge areas.

  The drive shaft 1 is supported by the pump body 10 via a bush 26 that rotatably supports the drive shaft 1. The cam ring 4 and the side plate 6 are accommodated in a pump accommodating recess 10 a formed in the pump body 10.

  The pump cover 5 is fastened to the flange portion 10 b of the pump body 10, and the pump housing recess 10 a of the pump body 10 is sealed by the pump cover 5.

  On the side surface of the pump cover 5 that is in contact with the cam ring 4, two first suction ports 8 that are notched in an arc shape and open toward the suction region of the cam ring 4 and guide the hydraulic oil to the pump chamber 7 are formed. .

  On the side surface of the side plate 6 that is in contact with the cam ring 4, two second suction ports 9 that are cut out in an arc shape and open toward the suction region of the cam ring 4 to guide the hydraulic oil to the pump chamber 7 are formed. . The second suction port 9 is formed so as to open also on the outer peripheral surface of the side plate 6. The side plate 6 is also formed with two discharge ports (not shown) that open toward the discharge region of the cam ring 4 and guide the hydraulic oil discharged from the pump chamber 7.

  An arcuate recess 16 is formed on the inner peripheral surface of the pump housing recess 10 a of the pump body 10. The recess 16 and the outer peripheral surface of the cam ring 4 form a communication path 17 that connects the first suction port 8 and the second suction port 9. Thus, the communication path 17 is formed on the outer peripheral side of the cam ring 4 so as to bypass the cam ring 4.

  In the cam ring 4, two suction through ports 20 having an opening 20 a that opens toward the communication path 17 and an opening 20 b that opens toward the suction region of the cam ring 4 are formed. As described above, the suction through port 20 is formed as a through hole having the opening 20 a and the opening 20 b on each of the outer peripheral surface and the inner peripheral surface of the cam ring 4, and guides the hydraulic oil in the communication passage 17 to the pump chamber 7. .

  The suction through port 20 is a long hole extending along the suction region of the cam ring 4, and the dimension in the longitudinal direction is formed shorter than that of the suction region. In addition, the opening 20 b that opens toward the suction region of the cam ring 4 in the suction through port 20 is formed at a substantially central portion in the thickness direction of the cam ring 4 so that the working oil can sufficiently reach the central portion of the pump chamber 7. Is done.

  In addition, in order to prevent the turbulent flow of the hydraulic fluid flowing through the suction through port 20, it is desirable to provide chamfering at the opening 20 a and the opening 20 b of the suction through port 20.

  The side plate 6 is provided with two positioning pins 14 that are inserted through the cam ring 4 and inserted into the pin holes 5 a of the pump cover 5. The positioning pin 14 restricts the relative rotation of the pump cover 5 and the side plate 6 with respect to the cam ring 4 and prevents the first suction port 8, the second suction port 9, and the discharge port from being displaced relative to the pump chamber 7.

  The pump cover 5 is formed with a suction passage 11 that communicates with the first suction port 8 and guides hydraulic oil to the first suction port 8. Further, the pump body 10 is formed with a high-pressure chamber 12 that communicates with the discharge port and into which hydraulic oil discharged from the discharge port flows.

  Next, the operation of the vane pump 100 will be described.

  When the engine power is transmitted to the drive shaft 1 and the rotor 2 rotates, the pump chamber 7 that expands between the vanes 3 as the rotor 2 rotates is connected to the suction passage 11 through the suction ports 8, 9, and 20. Inhale hydraulic fluid. Moreover, the pump chamber 7 in which the space between the vanes 3 contracts discharges hydraulic oil to the high-pressure chamber 12 through the discharge port. The hydraulic oil in the high pressure chamber 12 is supplied to a fluid pressure actuator (not shown) that applies a steering assist force in the power steering device through a discharge passage (not shown) communicating with the high pressure chamber 12.

  The flow of hydraulic oil sucked into the pump chamber 7 will be described in detail.

  The hydraulic oil in the suction passage 11 is sucked into the pump chamber 7 from the first suction port 8 and is branched to the communication passage 17. The hydraulic oil that has flowed into the communication passage 17 flows into the suction through port 20, and flows into the second suction port 9 by bypassing the cam ring 4 from the outer peripheral side of the cam ring 4 through the communication passage 17. And it is sucked into the pump chamber 7 from the second suction port 9.

  As described above, the hydraulic oil is guided to both sides of the pump chamber 7 through the first suction port 8 and the second suction port 9, and is also guided to the central portion through the suction through port 20. Therefore, the hydraulic oil is sufficiently distributed to the central portion of the pump chamber 7 that is difficult to reach only by the first suction port 8 and the second suction port 9.

  According to the present embodiment described above, the following effects can be obtained.

  Since the vane pump 100 includes a suction cover port 20 formed through the cam ring 4 together with the pump cover 5, the first suction port 8 formed on the side plate 6, and the second suction port 9 as a suction port. Even in the case of the cam ring 4 having a large discharge capacity, the hydraulic oil can be sufficiently distributed to the central portion of the pump chamber 7 through the suction through port 20.

  Therefore, it is possible to prevent damage to the equipment due to the occurrence of cavitation and occurrence of seizure due to insufficient lubrication of the sliding portion of the vane 3.

  Further, generally, the higher the speed of rotation, the shorter the time during which the pump chamber 7 communicates with the suction port, so that the hydraulic oil suction characteristic tends to deteriorate. However, since the vane pump 100 includes the suction through port 20 that guides the hydraulic oil to the central portion of the pump chamber 7, the hydraulic oil can be sufficiently distributed to the central portion of the pump chamber 7 through the suction through port 20 even during high-speed rotation. It is possible to prevent a reduction in hydraulic oil suction characteristics during high-speed rotation.

Other forms of this embodiment are shown below.
(1) As described above, when the suction through port 20 is formed as a long hole, the strength of the cam ring 4 tends to decrease as the longitudinal dimension increases. Therefore, the suction through port 20 may be formed as a plurality of through holes arranged along the suction region of the cam ring 4. In this case, the cross-sectional shape of each through hole may be any shape such as a round shape or a rectangular shape.
(2) Since the volume of the pump chamber 7 partitioned by the vanes 3 is small in the first half of the suction region of the cam ring 4, the suction through port 20 is formed even if the suction through port 20 is formed in the first half of the suction region of the cam ring 4. The flow rate of the hydraulic oil sucked into the pump chamber 7 through is not large. On the other hand, in the latter half of the suction area of the cam ring 4, the volume of the pump chamber 7 partitioned by the vanes 3 is large, and the suction function of the hydraulic oil in the pump chamber 7 is activated in preparation for the discharge process. Yes. Moreover, the strength of the cam ring 4 tends to decrease as the longitudinal dimension of the suction through port 20 increases. Therefore, in consideration of both the strength of the cam ring 4 and the suction characteristics, the suction through port 20 may be formed only in the latter half of the suction region of the cam ring 4 where the hydraulic oil suction function is active. By forming the suction through port 20 only in the second half of the suction region of the cam ring 4 as described above, the suction characteristics of the cam ring 4 are improved and the strength of the cam ring 4 is prevented from being lowered.
(3) In the above description, the communication passage 17 is formed by the recess 16 formed on the inner peripheral surface of the pump body 10 and the outer peripheral surface of the cam ring 4. Instead, the recess 16 is not formed on the inner peripheral surface of the pump body 10, but a groove is formed on the outer peripheral surface of the cam ring 4, and the communication path 17 is formed by the groove and the inner peripheral surface of the pump body 10. May be.
(4) In the above description, the rotor 2 and the cam ring 4 are sandwiched between the pump cover 5 and the side plate 6. Instead of this, the rotor 2 and the cam ring 4 may be sandwiched between the two side plates 6.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  The vane pump according to the present invention can be applied to a hydraulic pressure supply source of a power steering device for a vehicle.

It is sectional drawing which shows a cross section parallel to the drive shaft in the vane pump which concerns on embodiment of this invention.

Explanation of symbols

100 Vane Pump 1 Drive Shaft 2 Rotor 3 Vane 4 Cam Ring 5 Pump Cover 6 Side Plate 7 Pump Chamber 8 First Suction Port 9 Second Suction Port 10 Pump Body 11 Suction Passage 16 Recess 17 Communication Path 20 Suction Through Port

Claims (7)

A rotor coupled to the drive shaft;
A plurality of vanes provided so as to be capable of reciprocating in the radial direction with respect to the rotor;
A cam ring that houses the rotor, and the tip of the vane slides on the cam surface of the inner periphery as the rotor rotates.
A pair of side members disposed between both sides of the rotor and the cam ring, and defining a pump chamber between the rotor and the cam ring;
A suction port that is formed in each of the pair of side members and guides the working fluid to the pump chamber;
A communication path formed around the cam ring and connecting the suction ports of the pair of side members;
A suction through port formed through the cam ring and leading the working fluid from the communication path to the pump chamber;
A vane pump comprising: A pump body that houses the cam ring;
2. The vane pump according to claim 1, wherein the communication path is formed by an arcuate recess formed in an inner peripheral surface of the pump body and an outer peripheral surface of the cam ring. A pump body that houses the cam ring;
2. The vane pump according to claim 1, wherein the communication path is formed by a groove formed on an outer peripheral surface of the cam ring and an inner peripheral surface of the pump body.   The vane pump according to any one of claims 1 to 3, wherein the suction through port is a long hole extending along a suction region of the cam ring.   The vane pump according to any one of claims 1 to 3, wherein the suction through port is a plurality of through holes arranged along a suction region of the cam ring.   The opening part which opens toward the suction area | region of the said cam ring in the said suction penetration port is formed in the center part of the thickness direction of the said cam ring, The Claim 1 characterized by the above-mentioned. Vane pump as described.   The vane pump according to any one of claims 1 to 6, wherein the suction through port is formed in a rear half portion of the suction region of the cam ring.

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