JP6480841B2 - Vane pump - Google Patents

Description

  The present invention relates to a vane pump.

  Patent Document 1 discloses a rotor housed in a housing and driven to rotate, a vane that slides in a slit of the rotor, a cam ring that is outside the vane and forms a pump chamber with the rotor, the vane, and the like. , A vane pump is disclosed.

Japanese Patent Laid-Open No. 11-230057

  Since the hydraulic oil under a low temperature condition has a high viscosity and a large viscosity resistance, in the vane pump under a low temperature condition, the sliding of the vane is hindered by the viscous resistance of the hydraulic oil. For this reason, at the time of starting the vane pump under a low temperature condition, the pump chamber is not easily divided by the vane. Thus, the startability of the vane pump is reduced under low temperature conditions.

  The present invention has been made in view of the above problems, and an object thereof is to improve the startability of the vane pump.

  1st invention is a vane pump, Comprising: The rotor connected with the drive shaft, The some slit formed in the outer periphery of a rotor radially, and it is slidably inserted in each of a some slit A plurality of vanes, a cam ring having an inner peripheral surface on which a tip of the vane slides as the rotor rotates, and a pump chamber defined by the rotor, the cam ring, and a pair of adjacent vanes. Has a plurality of first vanes formed by subjecting the base material to DLC coating and a second vane formed by exposing the base material, and at least two adjacent slits among the plurality of slits Each is characterized in that a first vane is inserted.

  In the first invention, since the sliding resistance of the first vane to which the DLC coating is applied is small, the first vane easily protrudes from the slit due to the centrifugal force accompanying the rotation of the rotor even under a low temperature condition. For this reason, when starting the vane pump, the pump chamber is easily formed by the adjacent first vanes.

  The second aspect of the present invention further includes a back pressure chamber that is partitioned in the slit by the base end portion of the vane and into which the working fluid discharged from the pump chamber is guided.

  In the second aspect of the invention, the pump chamber is defined by two adjacent first vanes, whereby the working fluid is guided to the back pressure chamber, and the second vane also protrudes from the slit by the pressure of the working fluid in the back pressure chamber. To separate the pump chamber. As described above, the pump chamber 6a is partitioned by the two first vanes, so that the second vane can be projected from the slit.

  The third invention is characterized in that the plurality of vanes have two first vanes.

  In the third invention, since there are only two first vanes adjacent to each other, an increase in the manufacturing cost of the vane pump 100 can be suppressed while the pump chamber is partitioned by the first vane at the time of starting.

  According to a fourth aspect of the invention, the plurality of vanes have three first vanes, and the three first vanes are arranged side by side in succession.

  According to the fourth invention, since the two pump chambers are partitioned by the first vane at the time of starting, the flow rate of the working fluid discharged from the pump chamber at the time of starting can be increased.

  In the fifth invention, the plurality of vanes have four first vanes, and the four first vanes are arranged such that a pair of adjacent first vanes face each other across the center of the rotor. It is characterized by.

  In the fifth aspect of the invention, the pair of adjacent first vanes are arranged opposite to each other across the center of the rotor, so that even when the vane pump is stopped, the first vane is positioned below the rotor in the vertical direction and the pump chamber is It becomes easy to partition.

  According to the present invention, the startability of the vane pump is improved.

It is a front view of the vane pump concerning a 1st embodiment of the present invention. It is sectional drawing of the vane pump which concerns on 1st Embodiment of this invention. It is a front view of the vane pump which concerns on 2nd Embodiment of this invention. It is a front view of the vane pump which concerns on 3rd Embodiment of this invention.

(First embodiment)
First, with reference to FIG.1 and FIG.2, the whole structure of the vane pump 100 which concerns on 1st Embodiment of this invention is demonstrated.

  The vane pump 100 is used as a fluid pressure supply source for a fluid pressure device mounted on a vehicle, for example, a power steering device or a continuously variable transmission. In the present embodiment, a fixed displacement vane pump 100 using hydraulic oil as a working fluid will be described. The vane pump 100 may be a variable displacement vane pump.

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

  As shown in FIG. 1 and FIG. 2, the vane pump 100 includes a plurality of vanes 3 provided so as to be capable of reciprocating in the radial direction with respect to the rotor 2, and the rotor 2 accommodates the rotor 2 and rotates the rotor 2. A cam ring 4 having a cam surface 4a which is an inner peripheral surface on which the tip slides, a pump body 10 having an accommodating recess 10a for accommodating the cam ring 4, and a pump cover 11 fastened to the pump body 10 and sealing the accommodating recess 10a. And comprising. As shown in FIG. 2, the drive shaft is rotatably supported by the pump body 10.

  As shown in FIG. 1, the rotor 2 is formed with slits 7 opening in the outer peripheral surface in a radial pattern at predetermined intervals. The vane 3 is inserted into the slit 7 so as to be able to reciprocate. In the slit 7, a back pressure chamber 8 into which discharge pressure is guided is defined by the base end portion of the vane 3. Adjacent back pressure chambers 8 communicate with each other by a back pressure groove 8 a (see FIG. 2) formed in the pump cover 11.

  In the vane pump 100, twelve vanes 3 are provided. The vane 3 is pressed in the direction of coming out of the slit 7 by the pressure of the hydraulic oil guided to the back pressure chamber 8, and the tip portion comes into contact with the cam surface 4 a of the cam ring 4. As a result, a plurality of pump chambers 6 are defined within the cam ring 4 by the outer peripheral surface of the rotor 2, the cam surface 4 a of the cam ring, and the adjacent vanes 3. The configuration of the vane 3 will be described in detail later.

  The cam ring 4 is an annular member in which the inner peripheral cam surface 4a has a substantially oval shape. The cam ring 4 includes a suction region 4 b that expands the volume of the pump chamber 6 defined by the vanes 3 that slide on the cam surface 4 a as the rotor 2 rotates, and a discharge region 4 c that contracts the volume of the pump chamber 6. And having. Thus, each pump chamber 6 expands and contracts as the rotor 2 rotates. In the present embodiment, the cam ring 4 has two suction areas 4b and two discharge areas 4c.

  As shown in FIG. 2, the pump cover 11 is disposed in contact with one side of the rotor 2 and the cam ring 4 (upper side in FIG. 2), and the side plate 5 is in contact with the other side (lower side in FIG. 2). Arranged in contact. The pump cover 11 and the side plate 5 are disposed with both side surfaces of the rotor 2 and the cam ring 4 sandwiched therebetween, and seal the pump chamber 6.

  Two end ports 11a of the pump cover 11 on which the rotor 2 slides open corresponding to the two suction regions 4b (see FIG. 1) of the cam ring 4, and have two arc-shaped suction ports that guide the hydraulic oil to the pump chamber 6. (Not shown) is formed. Further, the pump cover 11 is formed with a suction passage (not shown) that communicates a tank (not shown) with a suction port and guides the hydraulic fluid of the tank to the pump chamber 6 through the suction port.

  The side plate 5 is formed with two arc-shaped discharge ports 20 that open corresponding to the discharge region 4 c of the cam ring 4.

  The pump body 10 is formed with a high pressure chamber 21 into which hydraulic fluid discharged from the pump chamber 6 in the discharge region 4c is guided. The hydraulic oil discharged from the pump chamber 6 is guided to the high pressure chamber 21 through the discharge port 20 of the side plate 5. The hydraulic oil guided to the high pressure chamber 21 is supplied to an external hydraulic device through a discharge passage (not shown) formed in the pump body 10 and communicating with the high pressure chamber 21.

  Further, two arc-shaped back pressure ports 22 communicating with the high pressure chamber 21 are formed in the side plate 5. Each back pressure port 22 communicates with the back pressure chamber 8. As a result, the hydraulic oil in the high pressure chamber 21 is guided to the back pressure chamber 8 through the back pressure port 22.

  As the rotor 2 rotates, the vane pump 100 sucks hydraulic oil from the tank through the suction port and the suction passage into each pump chamber 6 in the suction region 4b of the cam ring 4 and from each pump chamber 6 in the discharge region 4c of the cam ring 4. The hydraulic oil is discharged to the outside through the discharge port 20 and the discharge passage. In this way, the vane pump 100 supplies and discharges hydraulic oil by the expansion and contraction of each pump chamber 6 accompanying the rotation of the rotor 2.

  Next, the configuration of the vane 3 will be specifically described.

  As shown in FIG. 1, the plurality of vanes 3 includes a first vane 3a formed by applying a DLC (Diamond Like Carbon) coating to a base material, and a second vane 3b formed by exposing the base material. Have. The exposure of the base material means that the DLC coating is not applied over the entire vane 3 and the surface of the vane 3 remains the surface of the base material.

  The plurality of vanes 3 includes two first vanes 3 a that are inserted into the slits 7 adjacent to each other. Since the 1st vane 3a to which DLC coating was given is excellent in slidability, it is hard to receive to the influence of the viscous resistance of hydraulic fluid. For this reason, the first vane 3a easily protrudes from the slit 7 by the rotation of the rotor 2 even under a low temperature condition where the viscosity of the hydraulic oil is large and the viscosity resistance is large. Thereby, one pump chamber (hereinafter referred to as “initial pump chamber 6a”) is partitioned by the adjacent first vanes 3a, and the startability of the vane pump 100 under a low temperature condition is improved.

  Further, since the initial pump chamber 6 a is partitioned by the two adjacent first vanes 3 a, a part of the hydraulic oil discharged from the initial pump chamber 6 a is passed through the high pressure chamber 21 and the back pressure port 22 to the back pressure chamber. 8 leads. As a result, the second vane 3 b not subjected to DLC coating is also pressed in the direction of exiting from the slit 7 by the pressure of the back pressure chamber 8 and protrudes from the slit 7 to partition the pump chamber 6. Thus, by dividing the initial pump chamber 6a by the two first vanes 3a, it is possible to prompt the other vanes 3 to protrude from the slits 7 and to further improve the startability under low temperature conditions. be able to.

  Here, since the first vane 3a is excellent in slidability, the DLC coating is applied to the base material. For this reason, if all of the plurality of vanes 3 are formed as the first vane 3a in order to improve the startability of the vane pump 100, the manufacturing cost of the vane pump 100 increases.

  On the other hand, in the vane pump 100, the other ten vanes 3 excluding the two first vanes 3a are all formed as the second vane 3b. Even when there are only two adjacent first vanes 3a, the initial pump chamber 6a is partitioned by the first vane 3a at the time of starting, and the hydraulic oil discharged from the initial pump chamber 6a is guided to each back pressure chamber 8. Protrusion of the second vane 3b from the slit 7 is urged. Thereby, the startability of the vane pump 100 is sufficiently improved. Therefore, by forming only two adjacent ones of the 12 vanes 3 as the first vanes 3a, the startability of the vane pump 100 under a low temperature condition is improved and an increase in the manufacturing cost of the vane pump 100 is suppressed. be able to.

  In addition, the first vane 3a is also DLC-coated, thereby improving the wear resistance. Therefore, durability of the vane pump 100 is also improved.

  Next, a modification of the first embodiment will be described.

  In the first embodiment, the vane pump 100 has two suction areas 4b and two discharge areas 4c. Instead of this, the vane pump 100 may have one or three or more suction regions 4b and one or three or more discharge regions 4c.

  According to the above 1st Embodiment, there exists an effect shown below.

  In the vane pump 100, since the sliding resistance of the first vane 3a to which the DLC coating is applied is small, the first vane 3a easily protrudes from the slit due to the centrifugal force accompanying the rotation of the rotor 2 even under a low temperature condition. For this reason, when the vane pump 100 is started, the pump chamber 6a is easily formed by the adjacent first vanes 3a. Therefore, the startability of the vane pump 100 can be improved.

  In the vane pump 100, the initial pump chamber 6a is partitioned by the two adjacent first vanes 3a, so that the hydraulic oil is guided to the back pressure chamber 8 through the high pressure chamber 21 and the back pressure port 22, and the second vane. 3 b also protrudes from the slit 7 to define the pump chamber 6. Thus, by dividing the initial pump chamber 6a by the two first vanes 3a, it is possible to promote the protrusion of the second vane 3b from the slit 7, and further improve the startability under a low temperature condition. be able to.

  Further, in the vane pump 100, even when there are only two adjacent first vanes 3a, the initial pump chamber 6a is partitioned by the first vane 3a at the time of start-up, and the hydraulic oil is guided to each back pressure chamber 8, and the slit 7 Protrusion of the second vane 3b from is promoted. Therefore, by forming only two adjacent ones of the 12 vanes 3 as the first vanes 3a, the startability of the vane pump 100 under a low temperature condition is improved and an increase in the manufacturing cost of the vane pump 100 is suppressed. be able to.

(Second Embodiment)
Next, a vane pump 200 according to a second embodiment of the present invention will be described with reference to FIG. Below, it demonstrates centering on a different point from the said 1st Embodiment, the same code | symbol is attached | subjected to the structure same as the vane pump 100 of the said 1st Embodiment, and description is abbreviate | omitted.

  In the first embodiment, two adjacent first vanes 3a are provided, and all the vanes 3 except the first vanes 3a are formed as second vanes 3b. Instead of this, the vane pump 200 is different from the first embodiment in that three first vanes 3a are provided.

  As illustrated in FIG. 3, the vane pump 200 includes three first vanes 3 a and nine second vanes 3 b.

  The three first vanes 3a are arranged side by side and define two initial pump chambers 6a between each of them.

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

  In the vane pump 200, like the vane pump 100, since the sliding resistance of the first vane 3a to which the DLC coating is applied is small, the first vane 3a is caused by the centrifugal force accompanying the rotation of the rotor 2 even under a low temperature condition. It tends to protrude from the slit 7. For this reason, when the vane pump 200 is started, the initial pump chamber 6a is easily formed by the three consecutive first vanes 3a. Therefore, the startability of the vane pump 200 can be improved.

  Further, in the vane pump 200, like the vane pump 100, the initial pump chamber 6 a is partitioned by two adjacent first vanes 3 a, so that hydraulic oil is supplied to the back pressure chamber 8 through the high pressure chamber 21 and the back pressure port 22. As a result, the second vane 3b also protrudes from the slit 7 to partition the pump chamber. Thus, by dividing the two initial pump chambers 6a by the three first vanes 3a, it is possible to promote the protrusion of the second vane 3b from the slit 7, thereby further improving the startability under a low temperature condition. Can be improved.

  Further, in the vane pump 200, the first vane 3a easily protrudes from the slit 7 even at the time of starting, and the protruding first vane 3a is pushed into the slit 7 when entering the discharge region 4c. By the first vane 3a pushed into the slit 7, the hydraulic oil in the back pressure chamber 8 defined by the first vane 3a is guided to the back pressure chamber 8 in the adjacent suction region 4b through the back pressure groove 8a. Thereby, the protrusion of the vane 3 in the suction area 4b can be further promoted.

  Further, in the vane pump 200, since the two initial pump chambers 6a are partitioned, the flow rate of the hydraulic oil guided to the back pressure chamber 8 at the time of starting can be increased. Therefore, the 2nd vane 3b can be more reliably protruded from the slit 7, and the startability of the vane pump 200 can be improved more.

(Third embodiment)
Next, a vane pump 300 according to a third embodiment of the present invention will be described with reference to FIG. Below, it demonstrates centering on a different point from the said 2nd Embodiment, the same code | symbol is attached | subjected to the structure same as the vane pump 200 of the said 2nd Embodiment, and description is abbreviate | omitted.

  In the second embodiment, the two initial pump chambers 6a are partitioned by the three first vanes 3a arranged in succession. Instead, the vane pump 300 is different from the second embodiment in that the two initial pump chambers 6a are partitioned by the four first vanes 3a.

  As shown in FIG. 4, in the vane pump 300, the vane 3 includes four first vanes 3a and eight second vanes 3b.

  In the vane pump 300, the four first vanes 3 a are arranged such that a pair of adjacent first vanes 3 a face each other with the center of the rotor 2 interposed therebetween. That is, one initial pump chamber 6a is defined by two adjacent first vanes 3a, and two initial pump chambers 6a facing each other across the center of the rotor 2 are defined by four first vanes 3a. .

  According to the said 3rd Embodiment, in addition to the effect similar to the said 2nd Embodiment, there exists an effect shown below.

  In the vane pump 300, particularly when the central axis of the rotor 2 is provided so as to be inclined from the vertical direction, a part of the vanes 3 is moved downward in the vertical direction due to the influence of gravity and is in contact with the cam surface 4a. (The state in which the vane 3 protrudes from the slit 7) may be maintained even when the operation is stopped. In the vane pump 300, two initial pump chambers 6a facing each other across the center of the rotor 2 are partitioned, so that the vane pump 300 protrudes from the slit 7 when stopped compared to the vane pumps 100 and 200 according to the first and second embodiments. The first vane 3a is likely to be arranged at a position (particularly in the vertical direction below) that results in the above state. Therefore, in the vane pump 300, the initial pump chamber 6a is easily partitioned from the stop time, and the startability can be further improved.

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

  The vane pumps 100, 200, and 300 are slidably inserted into the rotor 2 connected to the drive shaft 1, the plurality of slits 7 that are radially formed in the outer periphery of the rotor 2, and the plurality of slits 7. Pumps defined by a plurality of vanes 3, a cam ring 4 having a cam surface 4 a on which a tip of the vane 3 slides as the rotor 2 rotates, and a pair of adjacent vanes 3. And a plurality of vanes 3 having a plurality of first vanes 3a formed by applying a DLC coating to the base material, and second vanes 3b formed by exposing the base material. The first vane 3 a is inserted into at least two adjacent slits 7 among the plurality of slits 7.

  In this configuration, since the sliding resistance of the first vane 3a to which the DLC coating is applied is small, the first vane 3a easily protrudes from the slit 7 due to the centrifugal force accompanying the rotation of the rotor 2 even under a low temperature condition. For this reason, when the vane pumps 100, 200, and 300 are started, the initial pump chamber 6a is easily formed by the adjacent first vanes 3a. Therefore, the startability of the vane pumps 100, 200, 300 is improved.

  The vane pumps 100, 200, and 300 further include a back pressure chamber 8 that is partitioned in the slit 7 by the base end portion of the vane 3 and into which hydraulic oil discharged from the pump chamber 6 is guided.

  In this configuration, when the initial pump chamber 6a is partitioned by the two adjacent first vanes 3a, the working oil is guided to the back pressure chamber 8, and the pressure of the working oil in the back pressure chamber 8 causes the second vane 3b. Projecting from the slit 7 to define the pump chamber 6. Thus, by dividing the initial pump chamber 6a by the two first vanes 3a, it is possible to promote the protrusion of the second vane 3b from the slit 7, and further improve the startability under a low temperature condition. be able to.

  In the vane pump 100, the plurality of vanes 3 includes two first vanes 3a.

  In this configuration, even if there are only two adjacent first vanes 3a, the initial pump chamber 6a is partitioned by the first vane 3a at the time of start-up, and the hydraulic oil is guided to each back pressure chamber 8, and from the slit 7 Protrusion of the second vane 3b is prompted. Accordingly, by forming only two adjacent ones of the plurality of vanes 3 as the first vanes 3a, the startability of the vane pump 100 under a low temperature condition is improved, and an increase in the manufacturing cost of the vane pump 100 is suppressed. Can do.

  The vane pump 200 includes three first vanes 3a, and the three first vanes 3a are arranged side by side.

  In this configuration, since the two initial pump chambers 6a are partitioned, the flow rate of the hydraulic oil guided to the back pressure chamber 8 at the time of starting can be increased. Therefore, the 2nd vane 3b can be more reliably protruded from the slit 7, and the startability of the vane pumps 200 and 300 can be improved more.

  The vane pump 300 includes four first vanes 3 a, and the four first vanes 3 a are arranged such that a pair of adjacent first vanes 3 a are opposed to each other with the center of the rotor 2 interposed therebetween.

  In this configuration, since the pair of adjacent first vanes 3a are arranged to face each other across the center of the rotor 2, the first vane 3a is located below the rotor 2 in the vertical direction even when the vane pump 300 is stopped. It becomes easy to partition the initial pump chamber 6a. Therefore, the startability of the vane pump 300 can be further improved.

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

  100, 200, 300 ... vane pump, 1 ... drive shaft, 2 ... rotor, 3 ... vane, 3a ... first vane, 3b ... second vane, 4 ... cam ring, 4a ... cam surface, 6 ... pump chamber, 7 ... slit , 8 ... Back pressure chamber

Claims (5)

A rotor coupled to the drive shaft;
A plurality of slits formed radially in the outer periphery of the rotor;
A plurality of vanes slidably inserted into each of the plurality of slits;
A cam ring having an inner peripheral surface on which the tip of the vane slides as the rotor rotates;
A pump chamber defined by the rotor, the cam ring, and a pair of adjacent vanes;
The plurality of vanes is
A plurality of first vanes formed by applying a DLC coating to the base material;
A second vane formed by exposing the base material,
The vane pump, wherein the first vane is inserted into at least two adjacent slits of the plurality of slits.   2. The vane pump according to claim 1, further comprising a back pressure chamber which is partitioned in the slit by a base end portion of the vane and into which a working fluid discharged from the pump chamber is guided.   3. The vane pump according to claim 1, wherein the plurality of vanes includes two first vanes. The plurality of vanes have three first vanes,
The vane pump according to claim 1 or 2, wherein the three first vanes are arranged side by side. The plurality of vanes have four first vanes,
3. The vane pump according to claim 1, wherein the four first vanes are arranged such that a pair of adjacent first vanes face each other across the center of the rotor. 4.

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