JPH1054375A - Shut-off vane pump - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a shut-off vane type pump having a simple configuration and restricting a transfer amount. A suction section (44) is provided with a throttle section (61), and a pressurized discharge section (42) is provided with a check valve (52).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a casing for accommodating a rotating body, at least one groove for accommodating a blocking blade is formed in a wall of the casing, and the blocking blade is separated from each other by a separating portion. A plurality of spaces having variable volumes are pressed against each other by an elastic element against a peripheral surface of a rotating body having a control surface, and a plurality of spaces having variable volumes are separated from each other by a rotating motion of the rotating body. The present invention relates to a shutoff vane type pump which communicates with a pressure discharge section, and a space behind the shutoff vane in a rotational direction communicates with a suction section.

[0002]

2. Description of the Related Art A shut-off vane type pump of this type is known. The shutoff vane type pump has a casing in which a rotating body is rotated. The peripheral surface of the rotating body has at least one control surface, and the control surface is partitioned on both sides of the separating portion when viewed in the circumferential direction. The control surface and the separating part cooperate with at least one blocking vane. The blocking blade is housed in a groove formed in the wall of the stationary casing and pressed against the control surface. The plurality of variable-volume spaces defined by the blocking blades are separated from each other by the rotational movement of the rotating body. Fluid is sucked in due to the periodic change in the volume of the space, and released again due to overpressure.

[0003] This type of shut-off vane pump can be used, for example, as a steering assist pump for a motor vehicle. The shut-off vane pump is driven via the drive of the motor vehicle, the transport of the shut-off vane pump being dependent on the speed. A disadvantage in this case is that the rotating body of the shut-off vane type pump is non-rotatably connected to the drive shaft of the drive device, so that when the running speed changes, the transport amount differs. For example, if you are driving on a highway at high speed,
Although there is no need for steering assistance when traveling straight ahead, a large amount of fuel is supplied which is unnecessary at this time.

[0004] When using a radial piston pump, an axial piston pump and a vane cell pump, it is known to incorporate a throttle in the suction area which limits the maximum transport of the pump to effect the suction throttle. However, since the displacement space is displaced, the suction stop cannot be realized unless a stop device having a very complicated structure is used. That is, a plurality of valve devices having a relatively large cross sectional area must be provided in each pressurizing chamber.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a shut-off vane pump of this kind which is simple in construction and limits the amount of transport.

[0006]

In order to solve the above-mentioned problem, the present invention is characterized in that a suction portion is provided with a throttle portion, and a pressure-dependent discharge device is provided with a pressure-dependent opening / closing device. Things.

[0007] According to the present invention, since the throttle portion is provided at the suction portion and the pressure-dependent opening / closing device is provided at the pressurizing / discharging portion, it is possible to easily limit the transport amount. A pressure-dependent switching device (advantageously formed as a check valve) controls the fluid / bubble mixture generated in the throttle and opens the communication to the pressurized side of the shut-off vane pump. Compress the gas component of the fluid-foam mixture. The compression of the gas component causes a re-dissolution of this gas component in the fluid, so that the pressure-dependent switchgear only opens when the fluid is not confining the gas, and thus activates the shut-off vane pump. Open the path to the pressure discharge section. In particular, in the shut-off vane type pump according to the present invention, one suction chamber and one pressurizing chamber can be uniquely associated with each other. Only the reaction of the compression process can be prevented.

Since only one opening / closing device is provided, the structure for the suction throttle is simplified. For example, the structure is remarkably compared with a vane cell pump provided with a plurality of switching devices for each pressurizing chamber. Be concise. In the case of the shut-off vane type pump, the suction chamber and the pressurizing chamber are uniquely related, that is, the suction chamber and the pressurizing chamber have a fixed angular position, and there is no displacement space for displacement. Thus, the suction throttle already known from the vane cell pump can be very easily diverted to a shut-off vane pump.

In the present invention, it does not matter how many shut-off vanes the pump has and therefore how many suction or pressurizing chambers. When a plurality of blocking blades are provided, one pressure-dependent opening / closing device can be attached to each of the pressurizing chambers. The superposition of the individual volume flows of the respective pressure chambers results in a volume flow with little pulsation.

In an advantageous embodiment of the invention, the opening pressure of the switchgear can be adjusted. This makes it possible to set the opening pressure so as to match the operating state of the shut-off vane type pump. In particular, the process of re-dissolving the gas components in the transported fluid can be optimized, so that the opening and closing device opens only at the compression stage in which the gas components of the fluid / bubble mixture are completely re-dissolved. The opening pressure of the switchgear can easily be adapted to the various fluids to be conveyed (eg oil) and / or the various conditions of use of the shut-off vane pump as required.

In an advantageous embodiment of the invention, the shape of the contour of the control surface is selected in such a way that the re-dissolution of the fluid / foam mixture before the pressure-dependent switching device is favorable. Advantageously, this profile is such that the remelting takes place gently, i.e., the compression of the gaseous component of the fluid-foam mixture in front of the pressure-dependent switchgear does not occur rapidly, but rather the rotation of the rotating body. , So that rapid volume changes due to gas concentration and redissolution are avoided.
This reduces the possibility that the pressure impulse accompanying this process will adversely affect the mechanical strength of the shut-off vane pump and its transport characteristic curve.

In still another configuration of the present invention, the back surface of the blocking blade is urged by the pressure in the pressurizing chamber. As a result, the pressing force of the blade against the contour of the rotating body can be adapted to the dynamic process in the pressurizing chamber, which is very advantageous. Therefore, the pressure peak caused by the re-dissolution of the gas component simultaneously acts on the back surface of the blocking blade, so that the pressure peak does not separate the blocking blade from the contour of the rotating body against the elastic force of the elastic element. . Therefore, the occurrence of a short circuit between the pressurizing chamber and the suction chamber is prevented.

[0013] Many advantageous configurations of the invention are evident from the other configurations described in the dependent claims.

[0014]

Next, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a partial view of a shut-off vane type pump 10. The shut-off vane type pump 10 includes a casing 12.
have. The casing 12 has a circular pump chamber 14. A rotating body 16 is supported inside the pump chamber 14, and the rotating body 16 can be driven by a drive shaft 18. The drive shaft 18 can be driven via a power machine (not shown), for example, an automobile drive machine, so that the rotating body 16 can rotate inside the pump chamber 14. In the illustrated embodiment, the rotating body 16 can be driven in a counterclockwise direction.

The rotating body 16 is formed in a disk shape, and is separated from a plurality of (six in the illustrated embodiment) control surfaces 22 on the peripheral surface 20 shifted from the circular contour. Part 24. The control surfaces 22 and the separation portions 24 are always provided alternately when viewed in the circumferential direction, so that each control surface 22 is partitioned by two separation portions 24. The maximum diameter of the rotating body 16 is such that the outer diameter of the rotating body in the region of the separation part 24 is substantially equal to the peripheral wall 26 of the pump chamber 14.
Is selected to correspond to the inner diameter of The diameter given to the rotating body 16 in the area of the separating part 24 is larger than the diameter of the rotating body in the area of the control surface 22 formed by the so-called radially extending area.

In the illustrated embodiment, the drive shaft 1 is provided on the peripheral wall 26.
A groove 28 is formed radially with respect to the groove 8. The blocking blade 30 is inserted into the groove 28. The width of the blocking blade 30 measured perpendicular to the plane of FIG. 1 substantially corresponds to the thickness of the rotating body 16. The length of the blocking blade 30 measured in the radial direction is shallower than the depth of the groove 28. The thickness of the blocking blade 30 is somewhat smaller than the width of the groove 28, so that the blocking blade 30 is supported and guided in a radially movable manner against the elastic force of the elastic element (for example, the compression spring 32). .
In FIG. 1, the compression spring 32 is shown only in the groove on the left side of the figure for the sake of simplicity, but each of the blocking blades 30
Is urged by the elastic force in the radial direction via the compression spring 32. The blocking blade 30 is a compression spring 32
As a result, the rotating body 16 is pressed against the peripheral surface 20 of the rotating body 16. The abutment surface of the blocking vane 30 on the rotating body 16 is inclined in the illustrated embodiment, so that a substantially linear contact with the peripheral surface 20 of the rotating body 16 is obtained. The strength of the pressing force of the compression spring 32 is selected such that the blocking blade 30 is pressed against the peripheral surface 20 of the rotating body 16 at all driving speeds. In the case of the embodiment shown in FIG. 1, a total of four grooves 28 for movably supporting the blocking blade 30 are provided therein, and these grooves 18 are 90 ° apart from each other.
Are arranged on the peripheral wall 26 of the casing 12 at an angular interval of.

The six separating sections 24 are arranged at an angle of 60 ° in the circumferential direction of the rotating body 16 so that the separating sections 24
The control surfaces 22 between them are likewise arranged offset from each other by an angle of 60 °. The control surfaces 22 of the separating section 24 all extend with exactly the same curve, ie have the same contour. The control surface 22 includes a first contour portion 34 and a second
Contour portion 36. Both contour parts 34 and 36
Are connected to each other via a portion 38 that is curved in an arc shape. As viewed in the direction of rotation 40 of the rotating body 16, the first contour portion 34 precedes the second contour portion 36. The contour portions 34 and 36 each transition into a curved portion 38 from or toward the separating portion 24. The contour portions 34 and 36 may, according to a variant embodiment not shown, extend mirror-symmetrically with respect to the curved portion 38 or have different extensions according to the functional aspects described below.

Each of the blocking blades 30 is provided with a pressure discharge section 42 and a suction section 44. In the illustrated embodiment, the pressure discharge section 42 is disposed before the blocking blade 30 in the rotation direction of the rotating body 16 indicated by the arrow 40, and the suction sections 44 are respectively disposed behind the blocking blade 30. The pressure discharge section 42 is provided in the casing 1
It is formed by a hole 46 that intersects the second peripheral wall 26. Hole 4
6 communicates with a communication duct 48 shown in a simplified manner.
The communication duct 48 communicates with the pressure connection of the shut-off vane type pump 10. The communication ducts 48 of all the pressure discharge sections 42 join the pressure connection section of the shut-off vane pump. Duct 50 communicating with pressure discharge section 42
Open in the groove 28 on the back side of the blocking blade 30. In the figure, the duct 50 is shown only for one blocking blade 30, but it is clear that all the blocking blades 30 are provided with this duct.

A check valve 52 is disposed inside the communication duct 48. The valve element 54 of the check valve 42 includes an elastic element 56
Seat 5 sealing the communication duct 48 by the elastic force of
8 has been pressed. According to an embodiment not shown, the elastic force of the elastic element 56 is adjustable, and thus the opening pressure of the check valve is variable.

The suction part 44 is formed by a communication duct 60 guided to penetrate the casing 12. The communication duct 60 is open to a suction connection portion of the shutoff vane type pump 10. The communication ducts 60 respectively attached to the shut-off vanes 30 join the common suction connection of the shut-off vane type pump 10. At the common suction connection of the shut-off vane pump 10, a throttle 61, shown schematically in the drawing, is attached. The restrictor 61 restricts the flow rate of the transported fluid sucked into the shut-off blade type pump 10. The construction and operation of such a diaphragm is well known and will not be described in detail herein. The suction of the shut-off blade type pump 10 is restricted by the restriction 61,
As a result, the shut-off vane pump 10 sucks in a substantially constant volume flow of the fluid to be conveyed regardless of the rotation speed of the rotating body 16. In this case, the suction restriction is performed irrespective of the number of the blocking blades 10 and the selection of the contour of the control surface 22.

The shut-off vane type pump 10 shown in FIG. 1 operates as follows. The casing 1 shown in FIG.
A part of 2 is arranged so that there is no pressure leak in the whole casing. For this reason, pressure plates may be provided on both sides of the rotating body 16. The pressure plate seals the pump chamber 14 against pressure leakage and has suitable passages for the pressure or suction connection.

The rotating body 16 is rotated via a drive shaft 18. The blocking blade 30 is pressed against the peripheral surface 20 of the rotating body 16 by the compression spring 30. Since the separating portion 24 and the control surface 22 are formed, the blocking blade 30 undergoes a radial movement during the rotation of the rotating body 16. In the region of the separating portion 24 (the outer periphery of which substantially corresponds to the inner periphery of the peripheral wall 26), the blocking blade 30 is located at its outermost position in the radial direction. When one control surface 22 passes, the blocking blade 30
Is pressed inward in the radial direction corresponding to the contour of the control surface 22 by the spring force of the compression spring 32. Each control surface 22
In the region (2), a constant volume chamber 62 is generated due to the contour of the control surface 22. All chambers 62 have the same volume. All chambers 62, ie six chambers in the illustrated embodiment, have the same volume.

When one control surface 22 is in the area of one blocking blade 30, the chamber 62 is divided into two regions 64 and 66 by the blocking blade 30 which is in close contact with the peripheral surface 20. The volume of the regions 64 and 66 depends on the rotation direction 40 of the rotating body 16.
Changes in response to The volume of the region 64 in front of the blocking vane 30 in the direction of rotation changes from a maximum value corresponding to the total volume of the chamber 62 to a minimum value ideally corresponding to zero. In this case, the time-dependent phenomenon of the volume is determined by the manner in which the contour portions 34, 36, 38 of the control surface 22 extend. The volume of the region 66 after the blocking vane 30 in the direction of rotation changes ideally from a minimum corresponding to zero to a maximum corresponding to the volume of the chamber 62. Since the volume of the region 66 is variable in this manner, the fluid to be conveyed is sucked from the suction portion 44 by expanding the region 66 to a volume corresponding to the entire volume of the chamber 62 inside the region 66. Inside the chamber 62, the fluid moves in the direction of the next pressurized discharge section 42, where it is pressurized and discharged. This pressurized discharge occurs due to the reduced volume in region 64, and the fluid is forced out of the pressure connection in the direction of arrow 68 under pressure.

The arrangement of the throttle 61 at the suction connection of the shut-off vane type pump 10 and the arrangement of the check valve 52 in the communication duct 48 provide the following features.

Since the throttle portion 61 forms a narrow portion with respect to the fluid (for example, oil) to be sucked, the oil is accelerated in the narrow portion, and at the same time, the pressure decreases. This causes the pressure to drop below the oil vapor pressure. Vapor bubbles are formed and an oil-bubble mixture is generated. This oil / bubble mixture is sucked by the area 66 whose volume is expanding, and is conveyed to the next pressurized discharge section 42. Since the volume of the region 64 is decreasing in the pressurizing and discharging unit 42, pressure is generated. Since the check valve 52 is closed, that is, the valve body 5
4 is seated on the valve seat 58 by the force of the spring 56 and the stuck operating pressure.
Is closed, the pressure rises without pressure equalization via the communication duct 48 being performed. As the check valve 52 closes, the oil-foam mixture being conveyed is compressed, resulting in an increase in pressure. This causes the vapor bubbles to redissolve in the oil. When the pressure further increases, the check valve 52 opens, that is, the valve element 54 separates from the valve seat 58 against the elastic force of the elastic element 56 due to the pressure of the transport oil. As a result, the communication with the pressure connection portion of the shutoff vane type pump 10 through the communication duct 48 is released.

As the oil-foam mixture is compressed in zone 64, a pressure peak occurs. This pressure peak also acts on the blocking vane 30. The pressure peak also occurs on the back surface of the blocking blade 30 in the groove 28, and as a result, the pressing force of the blocking blade 30 against the rotating body 16 increases. This allows
Due to the pressure increase in the region 64, the blocking vane 30 is pushed radially outward against the elastic force of the elastic element 32, and the blocking vane 30 is prevented from separating from the peripheral surface 20 of the rotating body 16. . When the blocking blade 30 is separated from the peripheral surface 20 in this manner, the regions 64 and 66 are short-circuited, and the blocking blade pump 1
This is undesirable because it hinders the transport characteristics of the zero. The duct 50 allows the shut-off vane 30 to be adapted to the kinetic process which takes place in the region 64, i.e. to the compression and the pressure development associated with the compression, followed by the pressure reduction by opening the check valve 52. be able to.

The dynamic process that takes place in the region 64 can be controlled by the shape of the contour of the control surface 22. In particular, by selecting the manner in which the contour portions 34 and 36 extend, it is possible to control the excluded volume per unit time, that is, to control the excluded volume when the volume of the chamber 62 is reduced from the maximum value to the minimum value. Can be. By appropriately controlling this rejection function, the compression of the oil-foam mixture before the check valve 52 opens can be adjusted with a characteristic curve that is as gentle as possible. Accordingly, since the gas component is not re-dissolved in a shock, the pressure peak in the region 64 due to the re-dissolution can be minimized. Therefore, the mechanical load on the shut-off vane pump 10 can be minimized as a whole.

As is apparent from the above description, it is possible to realize the shut-off vane type pump 10 which performs a throttle action at the time of suction by simple means. Since the pressurizing chamber (area 64) and the suction chamber (area 66) have a fixed attachment relationship, in order to limit the transport amount, a check valve with a simple structure is attached to each of the pressurizing chambers. Is enough. By optimizing the extension of the contour of the control surface 22, it is possible to advantageously control the kinetic process inside the fluid to be transported due to re-dissolution to be minimized. Furthermore, since the pressing force of the blocking blade 30 is adapted via the duct 50 to the dynamic characteristics in the pressurizing chamber, the functional stability of the blocking blade pump 10 is achieved. The shut-off vane type pump 10 according to the present invention is characterized in that its configuration is simple and robust.
By providing a plurality of blocking vanes 30 and cooperating with the six control surfaces 22, the volume flow pulsation is very low since the total volume flow is formed by overlapping partial volume flows.

[Brief description of the drawings]

FIG. 1 is a plan view showing an open state of a shut-off vane type pump according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Shut-off vane type pump 16 Rotating body 22 Control surface 28 Groove 30
Blocking blades 34, 36, 38 Contour part 42 Pressurized discharge part 44 Suction part 48 Communication duct
52 Check valve 61 Throttle section

Claims (9)

[Claims] A rotating body having a casing for accommodating a rotating body, wherein at least one groove for accommodating a blocking blade is formed in a wall of the casing, and the blocking blade has a control surface separated from each other by a separating portion. A plurality of spaces with variable volumes are pressed against each other by the elastic element against the peripheral surface of the body and are rotated by the rotating body, so that a space in front of the blocking blade in the rotating direction communicates with the pressurized discharge section. In the shut-off vane type pump in which the space behind the shut-off blade in the rotation direction communicates with the suction portion, a throttle portion (61) is attached to the suction portion (44), and the pressurized discharge portion (42) is provided. A shut-off vane type pump provided with a pressure-dependent switching device. 2. The shut-off vane type pump according to claim 1, wherein the pressure-dependent switching device is a check valve (52). 3. The check valve (52) includes a shut-off vane type pump (1).
3. The shut-off vane type pump according to claim 1, wherein the pump is disposed in a communication duct (48) communicating with the pressurized discharge section of (0). 4. The shut-off vane type pump according to claim 1, wherein the valve opening pressure of the check valve (52) is adjustable. 5. A check valve (52) is provided for each of a plurality of shut-off blades (30), and for each of a pressurized discharge section (42) provided for one of the shut-off blades (30). The shut-off vane type pump according to any one of claims 1 to 4, wherein: 6. A pressure chamber (6) having a pressure discharge section (42).
A pressure communication part (50) is provided between 4) and the groove (28) accommodating the blocking vane (30), and through this pressure communication part (50), the pressure communication part (50) is formed. 6. The blocking blade type according to claim 1, wherein the pressing force of the blocking blade (30) can be adapted to the pressure state in the pressurizing chamber (64). pump. 7. A method for controlling the time course of pressure generation in a pressure chamber (64) communicating with a pressure discharge section (42) while depressurizing the pressure chamber (64). Add contour to control surface (2
The shut-off vane type pump according to any one of claims 1 to 6, wherein 2) has. 8. The gentle compression of the gaseous component of the conveyed fluid / foam mixture before the pressure-dependent switching device is adjustable via the contour of the control surface (22). The shut-off vane type pump according to claim 7. 9. Over the course of time that the pressure chamber (64) communicating with the pressure discharge section (42) shrinks during its depressurization, the displacement volume is reduced by the contour (34) of the control surface (22). , 3
6, 38).
A shut-off vane type pump according to any one of claims 1 to 8.