JP3884986B2 - Vane pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vane pump that supports an inner end face of a vane with a vane ring.
[0002]
[Prior art]
As a conventional vane pump, an invention described in Japanese Patent Application Laid-Open No. 2000-97166 is known. The conventional vane pump supports the inner end surface of the vane with the vane ring and positively supports the outer end surface of the vane on the inner periphery of the cam ring so that a sufficient discharge pressure can be obtained at a low rotation even when the vane pump is started. To make contact.
FIG. 12 is a sectional view of a vane pump similar to this conventional example.
[0003]
As shown in the figure, a housing hole 2 is formed in the casing 1, and a cam ring 3 is inserted into the housing hole 2. A substantially elliptic cam ring hole 4 is formed on the inner periphery of the cam ring 3. A rotor 5 is rotatably incorporated in the cam ring hole 4. In the rotor 5, vane grooves 6 are formed radially, and a plurality of vanes 7 which are freely projectable with respect to the vane grooves 6 are incorporated.
Further, a back pressure introduction groove 8 that guides the discharge side high pressure to the rotor 5 is provided at the inner diameter side end of the vane groove 6.
[0004]
A vane ring 9 is provided inside the cam ring 3. The vane ring 9 has an elliptical shape substantially similar to the cam ring hole 4 of the cam ring 3.
The vane ring 9 is provided between a side plate (not shown) and the rotor 5 adjacent to the side plate, and the vane ring 9 is covered by the side plate and the rotor 5. That is, a groove for fitting the vane ring 9 is provided in the side plate, and one surface of the vane ring 9 is fitted. The rotor 5 is also provided with a vane ring groove 5a so that the other surface of the vane ring 9 is fitted.
[0005]
The side plate and the vane ring 9 are fixed without rotating. Therefore, the side plate 9 is provided with an elliptical groove having substantially the same cross section as the vane ring 9, and the vane ring 9 is fitted into this groove.
On the other hand, since the rotor 5 is rotatably provided, it rotates relative to the vane ring 9. In order to make the rotor 5 rotatable in this way, it is necessary to prevent the vane ring groove 5a and the vane ring 9 fitted in the vane ring groove 5a from colliding when the rotor 5 rotates. In order to prevent the vane ring groove 5 a and the vane ring 9 from colliding with each other, the vane ring groove 5 has a circular shape, and the diameter of the circular shape is the major axis of the vane ring 9.
[0006]
The outer periphery of the vane ring 9 is in contact with the inner end surface 7a of the vane 7 and supports the inner end surface 7a of the vane 7.
Further, by making the vane ring 9 substantially similar to the cam ring hole 4, the distance between the vane ring 9 and the cam ring hole 4 in the protruding direction of the vane 7 can be made equal. Specifically, the distance between the vane ring 9 and the cam ring hole 4 is a length obtained by adding a slight dimension to the length of the vane 7 in the protruding direction of the vane 7.
[0007]
As described above, the reason why the distance between the vane ring 9 and the cam ring hole 4 is slightly added to the length of the vane 7 is as follows. That is, in order to slide the vane 7 along the cam ring hole 4 as described below, a gap is required between the vane ring 9 and the cam ring hole 4 and the vane 7. If the distance between the vane ring 9 and the cam ring hole 4 exactly matches the length of the vane 7, the sliding property between the vane 7 and the cam ring hole 4 is deteriorated. Therefore, the distance between the vane ring 9 and the cam ring hole 4 is slightly larger than the length of the vane 7 so as to maintain the clearance.
[0008]
Further, the distance between the vane ring 9 and the cam ring hole 4 does not coincide with each other. This is because, depending on the location, the vane 7 is not supported vertically between the vane ring 9 and the cam ring hole 4, but is supported diagonally. Thus, the distance where the vane 7 is supported diagonally is shorter than the position where the vane 7 is supported vertically. Therefore, the shape of the vane ring 9 is not completely similar to the shape of the cam ring hole 4 but is substantially similar.
[0009]
In the configuration as described above, when the shaft 10 incorporated in the center of the rotor 5 is rotated, the rotor 5 is rotated along with the rotation.
When the rotor 5 rotates, the discharge pressure is guided to the back pressure introduction groove 8 through the vane ring groove 5 a provided in the rotor 5. The outer end surface 7 b of the vane 7 is pressed against the cam ring hole 4 of the cam ring 3 by the discharge pressure guided to the back pressure introduction groove 8 and the centrifugal force. Thus, the volume of the chamber formed between each vane 7 changes sequentially by rotating the rotor 5 in a state where the outer end surface 7b of the vane 7 is pressed against the cam ring hole 4.
[0010]
When the rotor 5 is rotated in the direction of the arrow k, hydraulic oil is sucked in the process in which the volume of the chamber between the vanes 7 increases, that is, in the volume expansion region indicated by the alternate long and short dash line S.
On the other hand, in the process in which the volume of the chamber between the vanes 7 is reduced, that is, in the volume reduction region indicated by the alternate long and short dash line T, the sucked hydraulic oil is discharged.
In the vane pump, the hydraulic oil can be discharged as described above.
[0011]
Further, by providing the vane ring 9, the vane 7 can be surely attached to the cam ring 3 even when the rotational speed of the rotor 5 is low, for example, when the operation of the vane pump is started or when the pressure of the back pressure introduction groove 8 decreases. The cam ring hole 4 can be contacted. Because there is only a slight gap between the outer end surface 7b of the vane 7 and the cam ring hole 4, the outer end surface can be obtained even when the centrifugal force is small or the pressure of the back pressure introduction groove 8 is low. This is because 7b can be reliably pressed against the cam ring hole 4.
[0012]
On the other hand, when the vane ring 9 is not provided, at the start of operation of the vane pump, not only a sufficient centrifugal force cannot be obtained, but also the pressure of the back pressure introduction groove cannot be obtained sufficiently. Therefore, the vane 7 does not contact the cam ring hole 4 firmly, and the chamber between the vanes 7 cannot be formed reliably. And the responsiveness of discharge will worsen.
Therefore, by providing the vane ring 9, the responsiveness at the start of the operation can be favorably maintained.
[0013]
[Problems to be solved by the invention]
In the above conventional example, in the volume reduction region indicated by the alternate long and short dash line T, the pressure is high because the pressure is the discharge pressure. This high pressure acts on the outer end surface 7 b of the vane 7. Thus, when a high pressure acts on the outer end surface 7b of the vane 7, the high pressure tries to push the vane 7 back against the pressure of the back pressure introduction groove 8 acting on the inner peripheral surface 7a. When a force to push back the vane 7 is generated, the pressure in the back pressure introduction groove 8 escapes to the pressure hole 18 side mainly through the vane ring groove 5a that guides the pressure to the back pressure introduction groove 8. . When the pressure in the back pressure introduction groove 8 escapes to the pressure hole 18, the vane 7 is pushed back inward.
[0014]
This is due to the following reason. That is, as described above, the vane ring groove 5a must have a circular shape whose diameter is the major axis of the vane ring 9, and the size of the vane ring groove 5a must be relatively large. When the vane ring groove 5a is made larger in this way, the pressure from the back pressure introduction groove 8 connected thereto is easily returned. Therefore, by providing the vane ring groove 5a, the vane 7 is pushed back inward.
In addition, in the vane pump which is not equipped with the vane ring, since it is not necessary to provide the large vane ring groove 5a, the groove communicating with the back pressure introduction groove 8 can be made very small. When this groove is small, it is possible to prevent the vane 7 from being pushed back by providing a squeezing effect.
[0015]
Another reason why the vane 7 is pushed back inward is due to the shape of the cam ring hole 4. That is, in the volume reduction region, the cam ring hole 4 has a shape in which the diameter decreases in the direction of the rotor 5, contrary to the volume expansion region. The force to push back to the 5 side acts and tries to push the vane 7 back inward.
[0016]
When a force for pushing back the vane 7 is generated due to the above two reasons, the pressure in the back pressure introduction groove 8 mainly leads to the back pressure introduction groove 8. It escapes to the pressure hole 18 side through 5a. In this way, the pressure oil in the back pressure introduction groove 8 moves toward the pressure hole 18, whereby the vane 7 is pushed back inward, and the cam ring hole 4 and the vane outer peripheral surface 7 b are separated from each other. A jumping phenomenon will occur.
[0017]
The amount of the vane 7 that is pushed back inward by the jumping is very small, but there is only a small gap between the vane 7 and the vane ring 9, so even if the vane 7 is pushed back slightly. The inner end surface 7 a of the vane 7 comes into contact with the vane ring 9.
When the inner end surface 7a of the vane 7 comes into contact with the vane ring 9, there is a concern about generation of abnormal noise or a decrease in discharge efficiency due to an increase in sliding resistance. Further, the vane ring 9 in the contacted portion may be worn and the wear powder may be mixed in the oil. And there existed a problem that a malfunction will arise in a pump by this abrasion powder.
[0018]
An object of the present invention is to provide a vane pump that not only prevents the generation of abnormal noise and wear powder by preventing jumping in which the vane is pushed back inward, but also prevents problems caused by a decrease in discharge efficiency. is there.
[0019]
[Means for Solving the Problems]
The first invention includes a casing, a side plate provided in the casing, a cam ring provided adjacent to the side plate, a rotor rotatably incorporated in a cam ring hole on the inner periphery of the cam ring, and a plurality of the rotors provided in the rotor. A vane groove, a vane that is incorporated in the vane groove and is radially projectable with respect to the rotor, a back pressure introduction groove that is provided on the inner end side of the vane groove and applies the back pressure of the rotor to the inner end surface of the vane, and the vane A volume reduction region in which the volume of the chamber formed by the vane, the rotor, and the cam ring is reduced by rotation of the rotor, and a volume expansion region in which the volume of the chamber is increased. In the vane pump that is formed and sucks oil in the volume expansion area and discharges oil in the volume reduction area, the volume reduction area is formed by a vane ring. Characterized in that it closes the back pressure introduction groove.
[0020]
The second invention is characterized in that a rotation prevention mechanism for preventing relative rotation between the side plate and the vane ring is provided.
According to a third aspect of the present invention, the vane ring includes a pedestal portion incorporated into the side plate and a support portion that supports the vane. The outer periphery of the support portion is substantially similar to the cam ring hole, and the pedestal is attached to the side plate. A built-in recess for incorporating the portion is formed.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
1 to 6 show a first embodiment of the present invention. This first embodiment is characterized by a vane ring 11 and a side plate 12 incorporating the vane ring 11. The components other than this feature are almost the same as in the conventional example. Therefore, the same components as in the conventional example will be described using the same reference numerals as in the conventional example. Further, detailed description of the same components as those in the conventional example is omitted.
[0022]
FIG. 1 is an overall cross-sectional view of the vane pump, and FIG. 2 is a cross-sectional view taken along the line II-II in FIG. However, the casing 1 is omitted in FIG.
As shown in FIGS. 1 and 2, a housing hole 2 is formed in the casing 1, and a side plate 12 is housed in the housing hole 2. And the built-in recessed part 13 which incorporates the vane ring 11 in this side plate 12 is formed, and the said vane ring 11 is incorporated in this built-in recessed part 13. As shown in FIG.
Further, a cam ring 3 is inserted into the storage hole 2. A substantially elliptic cam ring hole 4 is formed in the inner periphery of the cam ring 3 as shown in FIG. A rotor 5 is rotatably incorporated in the cam ring hole 4. In the rotor 5, a plurality of vanes 7 that are freely projectable are radially incorporated.
[0023]
A shaft hole 14 is formed in the casing 1, and the shaft 10 is rotatably supported in the shaft hole 14. Further, when the shaft 10 is fixed to the center portion of the rotor 5 and the shaft 10 is rotated, the rotor 5 is rotated.
Further, a cover 15 is fixed to the end surface of the casing 1 to close the housing hole 2 of the casing 1. The tip of the shaft 10 is rotatably supported in a bearing hole 16 formed in the cover 15.
[0024]
Further, as shown in FIG. 1, the casing 1 is formed with a high pressure chamber 17 to guide the hydraulic oil discharged to the high pressure chamber 17 and press the entire side plate 12 against the adjacent rotor 5 side by the pressure action. Yes.
Further, the pressure in the high pressure chamber 17 is guided to the back pressure introduction grooves 8 a and 8 b of the rotor 5 through the pressure hole 18 of the side plate 12 and the circular return groove provided in the rotor 5 adjacent to the pressure hole 18. ing. As shown in FIG. 2, the pressure guided to the back pressure introduction grooves 8a and 8b acts on the inner end surface 7a of the vane 7, and presses the vane 7 outward.
[0025]
The vane ring 11 includes a support portion 19 that supports the inner end surface 7a of the vane 7 and a pedestal portion 20, as shown in FIGS. As shown in FIG. 2, the outer periphery of the support portion 19 is substantially similar to the cam ring hole 4 of the cam ring 3.
As shown in FIG. 4, the pedestal portion 20 of the vane ring 11 is incorporated into the assembling recess 13 of the side plate 12. The assembling recess 13 has a circular shape. The pedestal portion 20 has a circular cutout shape, and the diameters of the built-in recessed portion 13 and the pedestal portion 20 are the same in diameter.
Therefore, when the pedestal portion 20 is incorporated into the incorporating recess 13, the vane ring 11 slides along the inner periphery of the incorporating recess 13.
[0026]
Further, as described above, the pedestal portion 20 has a circular cutout shape, but this is because the pedestal portion 20 does not block the pressure hole 18 as shown in FIG. Therefore, the pedestal portion 20 has a shape in which the circular shape is cut away so as to avoid the pressure hole 18.
[0027]
Further, as shown in FIG. 4, pins 21 and 21 are provided on the bottom surface of the built-in recess 13, and pin holes 22 and 22 corresponding to the pins 21 and 21 are formed in the vane ring 11. The pin 21 and the pin hole 22 form a relative rotation prevention mechanism referred to in the present invention.
When the vane ring 11 is assembled into the assembly recess 13 and the vane ring 11 is appropriately rotated, the pins 21 and 21 of the assembly recess 13 are inserted into the pin holes 22 and 22 of the vane ring 11. By inserting the pin 21 into the pin hole 22 in this way, relative rotation between the vane ring 11 and the built-in recess 13 can be prevented.
[0028]
Further, as shown in FIG. 6, the height of the pedestal portion 20 is made to coincide with the height of the built-in recess 13. Therefore, when the vane ring 11 is incorporated in the side plate 12, the pedestal portion 20 and the side plate 12 are flush with each other. On the other hand, the height of the support portion 19 is set to be higher than the height of the built-in recess 13. Accordingly, the support portion 19 protrudes from the built-in recess 13.
The protruding support portion 19 supports the inner end surface 7a of the vane 7. The support portion 19 protruding in this manner supports the inner end surface 7a of the vane 7 and the pedestal portion 20 and the side plate 12 are flush with each other. Therefore, even if the vane 7 rotates, the vane 7 remains pedestal. The part 20 is not caught.
[0029]
Further, as shown in FIG. 2, the support portion 19 of the vane ring 11 is thickened in the radial direction of the portion corresponding to the volume reduction region indicated by the alternate long and short dash line T. The back pressure introduction groove 8a of the rotor 5 located in this volume reduction region is closed. By closing the back pressure introduction groove 8a in this way, communication with the pressure hole 18 is blocked.
Further, the support portion 19 of the vane ring 11 is thickened as described above in the volume reduction region, but is located in this volume expansion region in the volume expansion region indicated by the alternate long and short dash line S. The thickness in the radial direction is made thin so as not to block the back pressure introduction groove 8b. In this way, in the volume expansion region, the back pressure introduction groove 8b is not blocked, so that the pressure hole 18 and the back pressure introduction groove 8b communicate with each other.
[0030]
In such a first embodiment, when the shaft 10 is rotated, oil is sucked in the volume expansion region and hydraulic oil is discharged in the volume reduction region. At this time, the volume reduction region becomes high pressure, and this high pressure acts on the outer end surface 7b of the vane 7 to push the vane 7 inward. However, the back pressure from the back pressure introduction groove 8 a acts on the inner end surface 7 a of the vane 7, and the back pressure introduction groove 8 a is blocked by one surface 19 a of the support portion 19 of the vane ring 11. . By thus closing the back pressure introduction groove 8a, it is difficult for the pressure in the back pressure introduction groove 8a to escape to the pressure hole 18 side.
[0031]
Therefore, the pressure of the back pressure introduction groove 8a in the volume reduction region can be maintained at a high pressure, and the vane 7 can be prevented from being pushed back inward.
Since the vane 7 can be prevented from being pushed back inward, the so-called jumping phenomenon of the vane 7 in which the inner end surface 7a of the vane 7 contacts the vane ring 11 can be prevented. Therefore, abnormal noise, wear powder, and the like are not generated, and further, problems such as a decrease in discharge efficiency due to an increase in sliding resistance can be prevented.
[0032]
Further, in the volume expansion region, the thickness in the radial direction of the support portion 19 of the vane ring 11 is reduced so as not to block the back pressure introduction groove 8b located in the volume expansion region. 8b and the pressure hole 18 are communicated with each other. Therefore, in this volume expansion region, a high pressure can be positively guided to the back pressure introduction groove 8b through the pressure hole 18.
Moreover, since the pedestal portion 20 of the vane ring 11 is also formed so as not to block the pressure hole 18, a higher pressure can be more easily guided to the back pressure introduction groove 8 b.
[0033]
7 and 8 show a second embodiment of the present invention. In the second embodiment, when the vane ring 23 is mounted as a rotation stop mechanism, the convex portion 24 is formed on the surface adjacent to the side plate 25. A recess 27 corresponding to the protrusion 24 is formed in the embedded recess 26 of the side plate 25. Therefore, the relative rotation between the side plate 25 and the vane ring 23 can be prevented by merely engaging the convex portion 24 of the vane ring 23 and the concave portion 27 of the side plate 25.
[0034]
In the second embodiment, when the pedestal portion 28 of the vane ring 23 is inserted into the built-in recess 26 of the side plate 25, it may be inserted properly without confirming the positional relationship between the protrusion 24 and the recess 27. Then, the convex part 24 and the concave part 27 can be engaged with each other by rotating the vane ring 23. Therefore, when assembling the pedestal portion 28 in the assembling recess 26, no special alignment is required, and assembling workability, that is, assembling efficiency is improved correspondingly.
As described above, in the second embodiment, the convex portion 24 and the concave portion 27 are easily engaged with each other, so that relative rotation between the vane ring 23 and the side plate 25 can be prevented easily and reliably. it can.
[0035]
The second embodiment is the same as the first embodiment except for the vane ring 23 and the side plate 25. Therefore, detailed description of the same components as those in the first embodiment is omitted here.
Further, the back pressure introduction groove 8a located in the volume reduction region is blocked by the one surface 29a of the support portion 29 of the vane ring 23, thereby preventing the vane 7 from being pushed back inward. This is the same as in the first embodiment.
[0036]
In the second embodiment, the convex portion 24 and the concave portion 27 are disposed in the volume reduction region. However, these positions are on the circumference as long as other functions are not hindered. It can be placed anywhere. Furthermore, there can be any number. Moreover, you may arrange | position a recessed part to the vane ring 23 side and a convex part to the side plate 25 side.
[0037]
9 to 11 show a third embodiment of the present invention. As shown in FIG. 9, a built-in recess 32 for incorporating the vane ring 31 is formed in the side plate 30. The built-in recess 32 has a circular cutout shape. That is, the built-in concave portion 32 forms a straight portion 33 obtained by cutting a part of the circumference with a straight line, and similarly forms the straight portion 33 at a line-symmetrical position.
Further, the pedestal portion 34 of the vane ring 31 also forms two straight portions 35 and 35 corresponding to the built-in concave portion 32.
In the third embodiment, the rotation preventing mechanism is formed by the straight portions 33 and 33 of the built-in recess 32 and the straight portions 35 and 35 of the pedestal portion 34.
[0038]
When the vane ring 31 is assembled into the assembling recess 32 of the side plate 30, the straight portions 35 and 35 of the pedestal 34 of the vane ring 31 and the straight portions 33 and 33 of the assembling recess 32 are made to coincide. The vane ring 31 and the side plate 30 do not rotate relative to each other by making the straight portions 33 and 35 coincide with each other.
Moreover, since the pedestal portion 34 can be incorporated into the assembling concave portion 32 so that the straight portions 33 and 35 coincide with each other, the positioning of the pedestal portion 34 and the assembling concave portion 32 can be very easily performed.
[0039]
Moreover, in this 3rd Embodiment, except the said vane ring 31 and the side plate 30, it is the same as that of 1st Embodiment. Therefore, detailed description of the same components as those in the first embodiment is omitted here.
Further, the back pressure introduction groove 8a located in the volume reduction region is closed with one surface of the support portion 36 of the vane ring 31, and thus the effect that the vane 7 can be prevented from being pushed back inward is obtained. This is the same as in the first embodiment.
In the third embodiment, the two straight portions 33 and 35 having the anti-rotation function are provided symmetrically, but either one may be provided. Moreover, the shape may not be a straight line as long as it is meshed in the circumferential direction so as to fulfill the function of preventing rotation.
[0040]
【The invention's effect】
According to the first invention, since the back pressure introduction groove in the volume reduction region is closed by the vane ring, the pressure of the back pressure introduction groove can be maintained at a high pressure, and the vane is prevented from being pushed back inward. The inner end face of the vane does not hit the vane ring. Therefore, it is possible to prevent problems such as a decrease in discharge efficiency due to an increase in sliding resistance without occurrence of abnormal noise or wear powder.
[0041]
According to the second invention, since with a rotation preventing mechanism for preventing relative rotation between the side plates and the vane ring, it can prevent relative rotation between the side plates and the vane ring.
[0042]
According to the third invention, the vane ring has a pedestal portion incorporated in the side plate and a support portion for supporting the vane, and the outer periphery of the support portion is substantially similar to the cam ring hole. Since the incorporation recess for incorporating the pedestal is formed, the vane ring can be easily incorporated into the side plate.
[Brief description of the drawings]
FIG. 1 is an overall sectional view of a first embodiment of the present invention.
FIG. 2 is a view showing a cam ring portion taken along the line II-II in FIG.
FIG. 3 is a front view of the vane ring of the first embodiment.
FIG. 4 is an assembled perspective view of a side plate and a vane ring.
FIG. 5 is a front view of a side plate.
FIG. 6 is a cross-sectional view in which a vane ring is incorporated in the side plate of the first embodiment.
FIG. 7 is a front view of a vane ring according to a second embodiment.
FIG. 8 is a cross-sectional view in which a vane ring is incorporated in a side plate of a second embodiment.
FIG. 9 is a front view of a side plate according to a third embodiment.
FIG. 10 is a front view of a vane ring of a third embodiment.
FIG. 11 is a diagram corresponding to FIG. 2 of the third embodiment.
FIG. 12 is a cross-sectional view of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Casing 3 Cam ring 4 Cam ring hole 5 Rotor 6 Vane groove 7 Vane 8a Back pressure introduction groove 11 Vane ring 12 Side plate 13 Built-in recessed part 19 Support part 20 Base part 21 Pin 22 Pin hole 23 Vane ring 24 Convex part 25 Side plate 26 Built-in Concave part 27 Concave part 28 Pedestal part 29 Support part 30 Side plate 31 Vane ring 32 Built-in concave part 33 Straight line part 34 Pedestal part 35 Straight line part 36 Support part

Claims (3)

A casing, a side plate provided in the casing, a cam ring provided adjacent to the side plate, a rotor rotatably incorporated in a cam ring hole on the inner periphery of the cam ring, a plurality of vane grooves provided in the rotor, and the vane A vane that is incorporated in the groove and can be protruded radially with respect to the rotor, a back pressure introduction groove that is provided on the inner end side of the vane groove and acts on the inner end surface of the vane, and supports the inner end surface of the vane A volume reduction region in which a volume of a chamber formed by the vane, the rotor, and the cam ring is reduced by rotation of the rotor, and a volume expansion region in which the volume of the chamber is enlarged are formed. In the vane pump that sucks oil in the area and discharges oil in the volume reduction area, the back pressure introduction groove in the volume reduction area is formed by the vane ring. Ida vane pump. The vane pump according to claim 1, further comprising an anti-rotation mechanism for preventing relative rotation between the side plate and the vane ring. The vane ring has a pedestal portion to be incorporated into the side plate and a support portion for supporting the vane. The outer periphery of the support portion has a shape substantially similar to the cam ring hole, and an incorporation concave portion to incorporate the pedestal portion into the side plate. The vane pump according to claim 1 or 2 formed.

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