Patent Application
20250198405
The invention relates to a rotary pump for delivering a fluid, the rotary pump comprising a pump housing having a first fluid connection and a second fluid connection, wherein the first fluid connection and the second fluid connection each open into a displacement chamber of the pump housing.
In the prior art, rotary pumps are also referred to as sliding vane rotary pumps or rotary vane pumps and are used for delivering fluids. Such pumps are usually used for delivering low-viscosity fluids. The functional principle is based on the displacement of the fluids. The pump consists of a hollow cylinder (stator) in which a further cylinder (rotor) rotates. The axis of rotation of the rotor is arranged eccentrically with respect to the stator. Two or more, usually radially arranged, guides are incorporated into the rotor. The sliding vanes or displacement elements are seated in these guides. These sliding vanes divide the space between stator and rotor into a plurality of chambers. In order to compensate for the change in distance between rotor and stator during a revolution, the sliding vanes can move radially along the guides.
A disadvantage of rotary pumps is, on the one hand, their comparatively high price with, at the same time, high wear. In addition, such rotary pumps have high leakages, as a result of which they are suitable only for medium pressures of up to 300 bar.
It is an object of the invention to provide an efficient concept of a rotary pump belonging to the technical field mentioned at the outset for delivering a fluid, which at least partially overcomes the disadvantages from the prior art.
The solution to the object is defined by the features of claim 1. According to the invention, the rotary pump for delivering a fluid comprises a pump housing having a first fluid connection and a second fluid connection, wherein the first fluid connection and the second fluid connection each open into a displacement chamber of the pump housing, a displacement rotor arranged in the displacement chamber, which is rotatable about an axis of rotation (D) in a first direction of rotation and a second direction of rotation opposite to the first direction of rotation; a plurality of displacement elements for delivering the fluid, which are distributed over the circumference of the displacement rotor and are radially movable with respect to the axis of rotation (D), wherein displacement elements are designed to deliver the fluid to be delivered from the first fluid connection to the second fluid connection when the displacement rotor is rotated in the first direction of rotation, and to deliver the fluid to be delivered from the second fluid connection to the first fluid connection when the displacement rotor is rotated in the second direction of rotation.
As a result, for example, the technical advantage is achieved that fluid can be delivered both from the first fluid connection through the pump housing to the second fluid connection and from the second fluid connection through the pump housing to the first fluid connection. For this purpose, only a change of the direction of rotation of the displacement rotor from the first direction of rotation to the second direction of rotation is necessary. The displacement elements, which are distributed over the circumference of the displacement rotor and are radially movable with respect to the axis of rotation (D), form fluid displacement chambers with the inner wall of the pump housing, which are designed to deliver the fluid depending on the direction of rotation of the displacement rotor both from the first fluid connection to the second fluid connection and from the second fluid connection to the first fluid connection. Overall, as a result of the change of its direction of rotation, the rotary pump is suitable for performing the task of two simple rotary pumps. The associated increase in efficiency can reduce both the manufacturing costs and the energy costs for operating the rotary pump. The displacement elements can also be referred to as slide elements or sliders.
According to an alternative solution, the object is achieved by a rotary pump for delivering a fluid, wherein the rotary pump comprises a pump housing having a first fluid connection and a second fluid connection. The first fluid connection and the second fluid connection each open into a displacement chamber of the pump housing. A displacement rotor arranged in the displacement chamber is rotatable about an axis of rotation (D) in a first direction of rotation and a second direction of rotation opposite to the first direction of rotation. The displacement rotor comprises a plurality of displacement elements for delivering the fluid, which are distributed over the circumference of the displacement rotor and are tangentially movable with respect to the axis of rotation (D). The displacement elements are designed to deliver the fluid to be delivered from the first fluid connection to the second fluid connection when the displacement rotor is rotated in the first direction of rotation, and to deliver the fluid to be delivered from the second fluid connection to the first fluid connection when the displacement rotor is rotated in the second direction of rotation.
As a result, comparable advantages result, as are achieved in the case of the preceding embodiment. The tangentially movable displacement elements are guided in pressure chambers, which are designed to be angled with respect to a geometrically radial orientation. As a result, the pressure chambers can be designed to be deeper in comparison to a radial orientation, because the axis of rotation (D) does not delimit the depth of the pressure chambers. In other words, the pressure chambers can be oriented past the axis of rotation by the tangential arrangement and can thus be designed to be deeper. This enables larger drive shafts for the displacement rotor and thus the transmission of larger torques. In connection with the displacement elements, this results in an increased delivery capacity.
All the following embodiments can be combined with this solution alternative without restriction.
According to an advantageous embodiment, the first fluid connection opens into a first chamber section of the displacement chamber and the second fluid connection opens into a second chamber section of the displacement chamber. The first chamber section forms a suction zone and the second chamber section forms a pressure zone when the displacement rotor rotates in the first direction of rotation. In addition, the first chamber section forms a pressure zone and the second chamber section forms a suction zone when the displacement rotor rotates in the second direction of rotation.
According to a further advantageous embodiment, two displacement elements, which are arranged adjacent to one another in the circumferential direction of the displacement rotor, together with an outer circumferential surface of the displacement rotor and an inner circumferential surface of the displacement chamber delimit a displacement cell, wherein the volume of the respective displacement cell increases in the suction zone and decreases in the pressure zone when the displacement rotor rotates about the axis of rotation D. As a result, for example, the technical advantage is achieved that the delivery capacity of the rotary pump is additionally increased. As a result of the displacement rotor, which is arranged eccentrically in the pump housing, the radially movable displacement elements are immersed deeper or less deeply into their associated pressure chamber in the displacement rotor depending on the distance between the displacement rotor and the inner circumferential surface of the displacement chamber. The fluid thus remains enclosed within the displacement cells, wherein the volume changes as a result of the eccentricity of the displacement rotor in the pump housing. If the volume within a displacement cell decreases, the pressure increases accordingly. This is the so-called pressure zone. If the volume within a displacement cell increases, the pressure decreases accordingly. This is the so-called suction zone.
According to a further advantageous embodiment, the radial movement of the displacement elements radially inward is delimited by a pressure chamber, wherein a fluid pressure which can be introduced into the pressure chamber presses the displacement elements radially outward. This is hydraulically connected to the pressure side of the pump unit. As a result, for example, the technical advantage is achieved that the displacement elements are at all times displaced out of their radially inwardly arranged pressure chamber. As a result of the fluid pressure which can be introduced into the pressure chamber, it is thus ensured that each displacement element is pressed radially outward from the pressure chamber in the best possible manner in order to form a displacement cell in interaction with the inner circumferential surface of the displacement chamber and thus the stator inner diameter. The radial movement of the displacement elements outward is thus delimited by the inner circumferential surface of the displacement chamber. Overall, the functionality of the rotary pump is additionally improved as a result and leakages at the displacement cell can be reduced.
According to a further advantageous embodiment, the pressure chamber is connected in a fluid-communicating manner either to the first chamber section or to the second chamber section depending on the direction of rotation of the displacement rotor. As a result, for example, the technical advantage is achieved that the pressure chamber is connected to fluid pressure in both directions of rotation. It is thus ensured that the displacement elements are at all times displaced out of the pressure chamber independently of the direction of rotation of the rotary pump. As a result, the functionality of the rotary pump is additionally improved and leakages can be further reduced.
According to an advantageous development of the invention, the pressure chamber is connected in a fluid-communicating manner to the second chamber section when the displacement rotor rotates in the first direction of rotation, and the pressure chamber is connected in a fluid-communicating manner to the first chamber section when the displacement rotor rotates in the second direction of rotation. As a result, for example, the technical advantage is achieved that the pressure chamber is always fluidically connected to a pressure zone. As a result, at all times it is ensured that the displacement elements are pressed outward from the pressure chamber in the radial direction in order to form a displacement cell in interaction with the inner circumferential surface of the displacement chamber. The radial movement of the displacement elements outward is thus improved, as a result of which the functionality of the rotary pump is additionally optimized and leakages are further reduced.
For example, the pressure chamber is connected in a fluid-communicating manner to the first fluid connection when the displacement rotor rotates in the second direction of rotation, and the pressure chamber is connected in a fluid-communicating manner to the second fluid connection when the displacement rotor rotates in the first direction of rotation. The technical advantage resulting therefrom is identical to the abovementioned embodiment according to which the pressure chamber is always connected to fluidic pressure and at all times it is ensured that the displacement elements are pressed outward from the pressure chamber in the radial direction.
According to a further advantageous embodiment, the pressure chamber can be connected in a fluid-communicating manner via a valve to the fluid connections and/or the chamber sections. As a result, for example, the technical advantage is achieved that the valve is connected to both chamber sections. The valve connects the respective chamber section which is under fluid pressure to the pressure chamber arranged radially below the displacement elements independently of the direction of rotation of the rotary pump.
According to a particularly preferred embodiment, the valve is a double-acting check valve. As a result, for example, the technical advantage is achieved that the switching of the valve takes place automatically when the direction of rotation of the rotary pump is reversed. As a result, the suction zone and pressure zone are exchanged, as a result of which the valve body of the double-acting check valve changes the seat such that the respective pressure zone always remains connected to the pressure chambers arranged radially below the displacement elements. Alternatively, the valve is designed as a logic element.
Preferably, the valve is a ball valve. The ball valve is a simple standard component with low wear.
According to a particularly preferred embodiment, the valve connects the pressure chamber in a fluid-communicating manner to the second fluid connection and/or the second chamber section, and fluidically separates the pressure chamber from the first fluid connection and/or from the first chamber section when the displacement rotor rotates in the first direction of rotation.
According to a further particularly preferred embodiment, the valve connects the pressure chamber in a fluid-communicating manner to the first fluid connection and/or the first chamber section, and fluidically separates the pressure chamber from the second fluid connection and/or from the second chamber section when the displacement rotor rotates in the second direction of rotation.
As a result, for example, the technical advantage is achieved that the pressure chamber is always fluidically connected to the pressure zone. At all times it is ensured that the displacement elements are pressed outward from the pressure chamber in the radial direction, as a result of which the functionality of the rotary pump is improved and leakages are reduced.
The valve is always connected to both chamber sections, wherein the respective chamber section which is under fluid pressure is connected to the pressure chamber independently of the direction of rotation of the rotary pump. The switching of the valve takes place automatically when the direction of rotation of the displacement rotor is reversed because the suction zone and pressure zone are exchanged. As a result, the valve body of the double-acting check valve is caused to change seat, as a result of which the fluid connection of the pressure zone to the pressure chamber is restored.
According to a further particular embodiment, the first fluid connection forms a low-pressure inlet and the second fluid connection forms a high-pressure outlet when the displacement rotor rotates in the first direction of rotation. The first fluid connection forms a high-pressure outlet and the second fluid connection forms a low-pressure inlet when the displacement rotor rotates in the second direction of rotation. As a result, the same advantages of the preceding embodiments are achieved. Thus, the pressure chamber is always fluidically connected to the pressure zone. At all times it is ensured that the displacement elements are pressed outward from the pressure chamber in the radial direction, as a result of which the functionality of the rotary pump is improved and leakages are reduced. In addition, the technical advantage results that fluid is sucked into the respective chamber section via the low-pressure inlet. Accordingly, fluid flows out via the high-pressure outlet with increased fluid pressure. This additionally improves the functionality of the rotary pump.
According to a preferred embodiment, the rotary pump is a rotary vane pump for delivering a hydraulic liquid. As a result, for example, the technical advantage can be achieved that an increase in efficiency can also be achieved during the delivery of hydraulic liquid. In particular, both the manufacturing costs and the energy costs for operating the rotary pump can be reduced.
A further variant of the invention relates to a fluid system for the chassis of a vehicle, wherein the fluid system has a rotary pump according to one of the preceding embodiments. As a result, the identical advantages of the preceding embodiments are achieved. In particular, an increase in efficiency is achieved because both the manufacturing costs and the energy costs for operating the rotary pump are reduced. In addition, the technical advantage can be achieved that the use of the rotary pump for raising or lowering a chassis of a vehicle can take place in a particularly simple manner. For example, it is possible to operate a plurality of actuators of a vehicle chassis with only one rotary pump.
A further variant of the invention relates to a fluid system having an actuator, preferably a chassis actuator. The actuator is connected in a fluid-communicating manner to one of the fluid connections such that the actuator can be fluidically pressurized and depressurized by the rotary pump. As a result, the identical advantages of the preceding embodiments are achieved. In particular, an increase in efficiency is achieved because both the manufacturing costs and the energy costs for operating the rotary pump are reduced. In addition, the technical advantage can be achieved that the use of the rotary pump is suitable for actuating one actuator or a plurality of actuators.
Further advantageous embodiments and combinations of features of the invention result from the following detailed description and the totality of the claims.
The drawings used to explain the exemplary embodiment show:
In principle, identical parts are provided with identical reference symbols in the figures.
Displacement elements 7 are arranged around the circumference of the displacement rotor 6. The displacement elements 7 serve to deliver fluid by virtue of the radially movable displacement elements 7 being arranged depending on the distance between the displacement rotor 6 and the inner circumferential surface 11 of the displacement chamber 5 and thus forming displacement cells 12. The fluid thus remains enclosed in the displacement cells 12, wherein the volume changes as a result of the eccentricity of the displacement rotor 6 in the pump housing 2.
When the displacement rotor 6 rotates counterclockwise, the fluid to be delivered is delivered from the first fluid connection 3 to the second fluid connection 4. When the displacement rotor 6 rotates clockwise, the fluid to be delivered is delivered from the second fluid connection 4 to the first fluid connection 3. The fluid can thus be delivered depending on the direction of rotation of the displacement rotor 6 both from the first fluid connection 3 to the second fluid connection 4 and from the second fluid connection 4 to the first fluid connection 3. It is only necessary to change the direction of rotation of the rotary pump 1.
As a result of the displacement rotor 6, which is arranged eccentrically in the pump housing 2, the radially movable displacement elements 7 are immersed into associated pressure chambers 13 in the displacement rotor 6 depending on the distance between the displacement rotor 6 and the inner circumferential surface 11 of the displacement chamber 5.
Two displacement elements 7, which are arranged adjacent to one another in the circumferential direction of the displacement rotor 6, together with the outer circumferential surface 10 of the displacement rotor 6 and an inner circumferential surface 11 of the displacement chamber 5 delimit a displacement cell 12. The volume of the fluid within the formed displacement cells 12 changes depending on the direction of rotation of the displacement rotor 6 in the pump housing 2. If the volume within a displacement cell 12 decreases, the pressure increases accordingly and forms a pressure zone. If the volume within a displacement cell 12 increases, the pressure decreases accordingly and a suction zone is formed.
The first fluid connection 3 opens into a first chamber section 8 of the displacement chamber 5. When the displacement rotor 6 rotates clockwise, the fluid to be delivered is delivered from the second fluid connection 4 to the first fluid connection 3. In the first chamber section 8 of the displacement chamber 5, the volume within the displacement cells 12 decreases, the pressure increases accordingly and forms a pressure zone. In the second chamber section 9 of the displacement chamber 5, the volume within the displacement cells 12 increases, as a result of which the pressure decreases accordingly and forms a suction zone.
By contrast, when the displacement rotor 6 rotates counterclockwise, the fluid to be delivered is delivered from the first fluid connection 3 to the second fluid connection 4. In the first chamber section 8 of the displacement chamber 5, the volume within the displacement cells 12 increases, as a result of which the fluid pressure decreases and forms a suction zone. In the second chamber section 9 of the displacement chamber 5, the volume within the displacement cells 12 decreases, as a result of which the pressure increases accordingly and forms a pressure zone.
The pressure chambers 13 delimit the radial movement of the displacement elements 7 radially inward. In order to press the displacement elements 7 radially outward as continuously as possible, a fluid pressure is introduced into the pressure chambers 13 below the displacement elements 7. The fluid pressure is introduced by the respective pressure zone of the displacement chamber 5 either from the first chamber section 8 or from the second chamber section 9 depending on the direction of rotation of the displacement rotor 6. Thus, there is a fluidic connection between the pressure chamber 13 and the second chamber section 9 when the displacement rotor 6 rotates in the first direction of rotation, i.e. counterclockwise. Accordingly, the pressure chamber 13 is connected in a fluid-communicating manner to the first chamber section 8 when the displacement rotor 6 rotates in the second direction of rotation, i.e. clockwise.
Depending on the direction of rotation of the displacement rotor 6, the valve body 18 is transferred either into the first valve seat 15 or into the second valve seat 16. When the displacement rotor 6 rotates, for example, in the first direction of rotation, i.e. counterclockwise, the fluid pressure in the second chamber section 9 of the displacement chamber 5 increases and a pressure zone is formed. The pressure acts via the second fluid connection 4 on the spherical valve body 18 and transfers it into the second valve seat 16. As a result, the fluid connection is formed from the pressure zone via the pressure chamber port 17 to the pressure chamber 13, as a result of which the displacement elements 7 are pressed radially outward. By contrast, when the displacement rotor 6 rotates in the second direction of rotation, i.e. clockwise, the fluid pressure in the first chamber section 8 of the displacement chamber 5 increases and a pressure zone is formed. The pressure acts via the first fluid connection 3 on the spherical valve body 18 and transfers it to the first valve seat 15. As a result, the fluid connection is again formed from the pressure zone via the pressure chamber port 17 to the pressure chamber 13, as a result of which the displacement elements 7 are pressed radially outward. The displacement elements 7 are thus pressed continuously radially outward independently of the direction of rotation of the displacement rotor 6. As a result, the functionality of the rotary pump is optimized and leakages are further reduced.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2022 107 716.0 | Mar 2022 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2023/055205 | 3/1/2023 | WO |
