JPH0442547Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to vane pumps, and in particular, to improvements in wear between the vanes and the pump chamber. related to things. [Prior Art] As a vane pump used for a pump that feeds fluid, vanes consisting of rollers are fitted into a plurality of grooves formed in a rotor so as to be able to move forward and backward, and the vanes receive pressure when the rotor rotates. By protruding from the groove and pressing against the inner circumferential surface of the pump casing due to centrifugal force, the vane maintains airtightness between adjacent pressure chambers, and the pressure chamber changes from the compression stroke to the suction stroke. Some are configured to go through a sealing process when transferring. [Problem to be solved by the invention] In such vane pumps, the wear that most affects the performance of the pump is the wear of the vanes and the pump chamber wall (inner circumferential surface of the cam ring). There is a problem that the amount of wear increases under conditions of low discharge pressure and low lubrication. One of the causes of this wear is the contact force that acts between the vanes and the wall surface of the pump chamber. This contact force is generated not only by the centrifugal force of the rotor but also by a differential pressure across the vane, such as a difference between the suction pressure and discharge pressure of the pump, and causes the vane to be pressed against the wall surface of the pump chamber. These contact forces change depending on the positions of the suction port and the discharge port, and then the pump chamber wall surface and the vane in the range where the contact force acts increases. That is, in the conventional vane pump, as shown in FIG. 6, the interval between the suction port 50 and the discharge port 51 is one pitch or less between the vanes 52, so that the vane 52 is separated from the suction port 50. While moving toward the discharge port 51 side, a contact force is generated due to the pressure difference between the discharge pressure and the suction pressure, and the vane 52 is pressed against the wall surface of the pump chamber 54 of the cam ring 53 by this contact force. This state continues until the next vane 52 passes through the suction port 50, and the wall surface of the pump chamber 54 and the vane wear out. Further, as shown in FIG. 7, strong contact force also acts near the top clearance 55.
This is because, while high pressure is generated from the discharge port 51 side, negative pressure is generated due to volume expansion after the vane 52 passes through the top clearance 55. This state continues until the previous vane 52 reaches the suction port 50, and wear areas 56 and 57 are formed on the wall surface of the pump chamber 54. Further, as shown in FIG. 8, the discharge port 5
1 is wider than the radius of the vane 52, when the vane 52 rotates as the rotor 58 rotates, one end of the vane 52 falls into the discharge port 51, and the vane 52 rotates while being inclined. , the edge of the discharge port 51 is worn out, and the vane 52
It also wears out, leading to a decrease in pump performance. An object of the present invention is to provide a vane pump that can suppress wear caused by rotation of the rotor. [Means for solving the problem] The vane pump according to the present invention has a pump chamber 15.
, a rotor 16 eccentrically disposed in the pump chamber 15 so as to be freely rotatable, a plurality of vane grooves 17 provided on the outer periphery of the rotor 16, and a plurality of vane grooves 17 that are fitted into these vane grooves 17 so as to be freely retractable. The roller vane 18 and the adjacent roller vane 18,1
8, the pump chamber 15 and the rotor 16 communicate with a pressure chamber 19 whose volume increases or decreases as the rotor 16 rotates, and a pressure chamber 19 whose volume gradually increases during the suction stroke. Suction port 24
and a discharge port communicating with the pressure chamber 19 in the compression stroke whose volume decreases, and the pitch between each roller vane 18 is an angle of (360/n) degrees, where the number of roller vanes 18 is n. In the set vane pump, the discharge port includes a first discharge port 21 located on the front side in the rotational direction of the rotor 16, and a second discharge port 22 located on the rear side in the same direction. The outlet 21 is communicated with the bottom of the vane groove 17 in the compression stroke so as to apply back pressure to the roller vane 18, and the starting end 21a of the first outlet 21 in the rotational direction is connected to the bottom of the vane groove 17 in the compression stroke. The starting end 24a of the rotor 16 in the rotational direction of the suction port 24 is located at a position angularly away from the top clearance 31 of the pump chamber 15 by (180+180/n) degrees. The rotation angle of the rotor 16 from the position of the top clearance 31 is (360/n) degrees or less, and is arranged at a position that is at least (360/n) degrees from the starting end 21a of the first discharge port 21, and The same terminal end 24b of the suction port 24
However, from the position of top clearance 31, rotor 1
The vanes are arranged at positions separated by (180-180/n) degrees at a rotation angle of 6, and furthermore, the interval between the terminal end 24b of the suction port 24 and the starting end 21a of the first discharge port 21 is one pitch of the vane. It is characterized by having the above settings. [Operation] According to the above-described means, when the rotor is rotated, the vanes are subjected to centrifugal force and revolve while moving back and forth with respect to the vane groove while maintaining pressure against the inner wall surface of the pump chamber. become. As the vanes revolve, the volume of each pressure chamber defined by adjacent vanes expands and contracts, and fuel is sucked in from the suction port and discharged from the discharge port. At this time, the vanes press against the wall surface of the pump chamber, but since the interval between the suction port and the discharge port is set to one vane pitch or more, the contact force due to the differential pressure between the discharge port and the suction pressure can be suppressed to a small level. I can do it. [Example] Fig. 1 is a schematic diagram showing a vane pump which is an embodiment of the present invention, Fig. 2 is an exploded perspective view of the vane pump, Fig. 3 is a distribution diagram showing the pressure distribution state of the vane pump, and Fig. 4 is a diagram showing a vane pump. FIG. 5 is a schematic diagram showing a vane pump which is another embodiment of the present invention. FIG. 5 is a schematic diagram showing a vane pump which is still another embodiment of the present invention. In this embodiment, the vane pump comprises a pump plate 12, a pump ring 13 and a pump head 14, which in turn are fixedly installed inside a casing (not shown).
The pump ring 13 has a large circular pump chamber 15, and the pump ring 13 is arranged so that the pump chamber 15 is eccentric with respect to the spindle of a motor (not shown). In the pump chamber 15, a rotor 16 formed in a substantially disk shape is disposed concentrically with the spindle and is housed in a rotatable manner with respect to the spindle and the pump ring 13. It is configured to be rotationally driven by being connected to the rotating shaft of the rotary shaft via a coupling ring. A plurality of vane grooves 17 are arranged on the outer periphery of the rotor 16 at approximately equal intervals in the circumferential direction.
The grooves 17 are cut radially, and a roller 18 serving as a vane is fitted into each groove 17 so as to be movable forward and backward in the radial direction. Then, the adjacent rollers 18 and 18 cooperate with the pump casing 11 to form a pressure chamber 19, and by changing the volume as the rotor 16 rotates, the pressure chamber 19 passes through the suction stroke, compression stroke, and sealing stroke. It's becoming like that. The pump head 14 is formed in a substantially disk shape, and in the center of the head 14 are a first discharge port 21 and a second discharge port 22 each having a substantially eyebrow shape, and a pressure chamber 19 formed by adjacent rollers 18, 18. The pressure chamber 1 is placed at a position where the volume of the pressure chamber 1 decreases.
It has been established so that it connects to 9. Also, the first
On the other hand, the discharge port 21 is formed to communicate with the vane groove 17 located in the compression stroke, and
This portion substantially constitutes the high pressure introduction section 26 on the compression stroke side. The pump plate 12 is formed into a substantially octagonal flat plate shape, and an arc-shaped suction port 24 is opened in this plate 12 so as to communicate with the pressure chamber 19 located in the suction stroke. This suction port 24 is configured to communicate with an inlet pipe (not shown) formed in the casing.
The inlet pipe is connected to a supply tank or the like. The suction port 24 has one end (starting end) 24a in the pump rotation direction at an angle (360/n) degrees from the position of the top clearance 31 of the pump chamber 15 in the pump rotation direction, where n is the number of rollers 18 serving as vanes. From the end of the discharge port (360/n)
The other end (terminus) 24b of the suction port 24 is set at an angle of approximately (180-180/n) degrees from the top clearance position. Also, one end (starting end) 21a of the first discharge port 21
is similarly set at a position approximately at an angle of (180+180/n) degrees from the position of the top clearance 31.
Furthermore, the starting end 24a of the suction port 24 and the second discharge port 2
The angle with the terminal end 22b of 2 is set to (360/n+θ) degrees. That is, the distance between the suction port 24 and both discharge ports 21 and 22 is set to be one pitch or more of each vane. The terminal end 24b of the suction port 24 is set to coincide with the position where the theoretical stroke volume is maximum, the first discharge port 21 is at an angle of (180+180/n) degrees or more, and the second discharge port 22 is set to coincide with the position where the theoretical stroke volume is the maximum. 18 is set at an arbitrary angle that does not cause binding. A recessed portion 26 is formed in the pump head 14 in a shape that is smaller and substantially similar to the first discharge port 21 as a high pressure introduction portion on the compression stroke side, and is recessed so as to communicate with the vane groove 17 located in the compression stroke. In other words, the recess 26 is connected to the first discharge port 21.
The vane groove 17 communicates with the vane groove 17. Next, the action will be explained. When the rotor 16 of the vane pump is rotated by the rotating shaft of the motor in the direction shown by the solid arrow A in FIG. Since the rotor 16 and the rotor 16 are eccentric,
The pump chamber 15 moves forward and backward with respect to the vane groove 17.
It revolves while maintaining pressure against the inner circumferential surface of. As the roller 18 revolves, each pressure chamber 19 defined by the adjacent rollers 18, 18
Since the volume of the liquid is expanded and contracted, the liquid to be pumped is sucked in from the suction port 24, discharged from the discharge ports 21 and 22, and sent out from the delivery port 9 to a desired point of demand. On the other hand, a portion of the high-pressure liquid discharged from the discharge ports 21 and 22 is introduced into the bottom of the vane groove 17. That is, the vane groove 17 located in the compression stroke
Since the roller 18 is in communication with the bottom of the pump chamber 15, the roller 18 in this stroke is strongly pressed against the inner circumferential surface of the pump chamber 15 due to back pressure. Therefore, adjacent pressure chambers 1 delimited by rollers 18
9 and 19, the mutual sealing performance is maintained well. Further, a part of the high-pressure liquid introduced from the first discharge port 21 to the bottom of the vane groove 17 located in the compression stroke enters the recess 26 of the pump head 14 that communicates with the bottom of the vane groove 17 on the opposite side. Flow into. Furthermore, this liquid is introduced into the bottom of the vane groove 17 on the suction stroke side via the recess 26.
That is, since this recess 26 is in communication with the bottom of the vane groove 17 located in the suction stroke, the roller 18 in this stroke receives back pressure and moves into the pump chamber 15.
It will be strongly pressed against the inner circumferential surface of the Therefore, the mutual sealability between the adjacent pressure chambers 19, 19 defined by the roller 18 is maintained well. By the way, as shown in FIG. 1, as the rotor 16 rotates, the roller 18 moves into the pump chamber 1.
It moves while pressing against the wall surface of 5, but the suction port 24
Since the and discharge port 21 are separated by one or more vane pitches, the differential pressure acting on the roller 18 between the suction port 24 and the discharge port 21 is suppressed, and the contact force can be reduced. Thereby, wear on the wall surface of the pump chamber 15 and the outer peripheral surface of the roller 18 can be reduced. However, if the distance between the suction port 24 and the discharge port 21 is too large, the compression ratio will increase, the pump internal pressure will be higher than the discharge pressure, and the pump chamber 15 will increase.
This results in increased wear on the walls and rollers 18. Furthermore, in this embodiment, even in the vicinity of the top clearance 31, the top clearance 3
Since the distance from the position 1 to the starting end 24a of the suction port 24 is one pitch of the vane, negative pressure due to volume expansion does not occur as in the conventional case, and the contact force can be reduced. The area of action can also be shortened. That is, the third
As shown in the figure, in this example,
The area on which the contact force of the discharge ports 21 and 22 acts can be made narrower than in the conventional case. Note that if the distance between the top clearance 31 and the starting end 24a of the suction port 24 is small, the sealing performance at the top clearance 31 will be reduced, and the efficiency of the pump will be reduced. Furthermore, the terminal end 24b of the suction port 24 is set at a position where the theoretical stroke volume is maximum, and
Since the distance to the first discharge port 21 is one vane pitch or more, it is possible to suppress the occurrence of backflow of fuel, and it is possible to suppress a decrease in pump efficiency. Here, the vane hump according to the present example and the conventional vane hump were tested under the test conditions of methanol as the test liquid, a discharge pressure of 40 kg/cm ² , and a time of 4 hours and 55 minutes. The test results as published were obtained. From Table 1, it is possible to reduce the wear of the roller 18 and the wall surface of the pump chamber 15, and also to contribute to improving the durability of the pump. Furthermore, it becomes possible to cope with conditions of high discharge pressure and low lubrication. As shown in FIG. 4, both discharge ports 21,
22, the first discharge port 21 in a portion corresponding to the inclined area of the roller 18 is connected to a plurality of discharge ports 21A, 21.
By dividing the roller 18 into the first discharge ports 21 and tilting, it was possible to reduce the wear of the first discharge ports 21A, 21B and the rollers. Furthermore, as shown in FIG. Since it is prevented from falling inward and tilting, it is possible to suppress the first discharge port 21C and the edges of the roller from being worn out. [Effects of the invention] As explained above, according to the invention, since the interval between the suction port and the discharge port is set to one vane pitch or more, the contact force due to the differential pressure between the discharge pressure and the suction pressure is reduced. It is possible to suppress wear of the pump chamber wall surface and vanes due to rotation of the rotor. Furthermore, by dividing the discharge port in the area corresponding to the slope area of each vane into multiple parts, or by setting the radial width of the discharge port to 1/2 or less of the diameter of the vane, the vane can be Since it is possible to prevent the discharge port from falling, wear of the discharge port and the vane can be further reduced. 【table】

Claims (1)

[Claims for Utility Model Registration] 1. A pump chamber 15, a rotor 16 that is eccentrically disposed in the pump chamber 15 and rotatable, a plurality of vane grooves 17 provided on the outer periphery of the rotor 16, and The roller vanes 18 are fitted into the vane grooves 17 so as to be freely retractable, and the pump chamber 15 is located between the adjacent roller vanes 18 and 18.
and rotor 16, rotor 1
6, a suction port 24 communicating with the pressure chamber 19 in the suction stroke whose volume gradually increases, and a pressure chamber in the compression stroke whose volume decreases. 19, and a discharge port communicating with the roller vane 1.
In a vane pump in which the pitch between each roller vane 18 is set to an angle of (360/n) degrees, where the number of 8 is n, the discharge port is a first discharge port 21 located on the front side in the rotational direction of the rotor 16. , and a second discharge port 22 located on the rear side in the same direction.
Vane groove 17 in which the discharge port 21 is in the compression stroke
is connected to the bottom of the roller vane 18 so as to apply back pressure to the roller vane 18, and the starting end 21a of the first discharge port 21 in the rotation direction is at the rotation angle of the rotor 16.
It is arranged at a position separated from the top clearance 31 of the pump chamber 15 by (180+180/n) degrees, and on the other hand, the starting end 24a of the suction port 24 in the rotational direction of the rotor 16 is located at a position apart from the top clearance 31 of the pump chamber 15. The rotation angle of the rotor 16 from the position 31 is (360/n) degrees or less, and is arranged at a position at least (360/n) degrees from the starting end 21a of the first discharge port 21, and the suction port The same terminal end 24b of 24 has a rotation angle of (180-180/) of the rotor 16 from the top clearance 31 position.
n) degree, and further, the interval between the terminal end 24b of the suction port 24 and the starting end 21a of the first discharge port 21 is set to be one pitch or more of the vane. vane pump. 2. The first discharge port 21 is divided into a plurality of parts in the rotation direction of the rotor 16, and the divided discharge ports 21A and 21B are arranged spaced apart from each other in the rotation direction of the rotor 16. A vane pump according to claim 1 of the patented utility model characterized by: 3. The vane pump according to claim 1, wherein the width of the first discharge port 21C in the radial direction is set to be less than half the diameter of the roller vane 18.