SEAL ARRANGEMENT FOR A SWITCHABLE VANE CELL PUMP OF CARTRIDGE DESIGN

Abstract

A seal arrangement for a vane cell pump of cartridge design which is configured such that it can be switched into multiple flows is described. The seal arrangement comprises a first seal which is arranged so as to run around the circumference of a side plate of the vane cell pump, and a second seal which is arranged so as to run around a shaft leadthrough which is provided in the side plate. The seal arrangement is distinguished by a third seal which, apart from at least one first fluid connection, shuts off at least a second fluid connection with respect to the at least one first fluid connection within a region which is configured between the first seal and the second seal.

Claims

1. A seal arrangement for a vane cell pump of cartridge design which is configured such that it can be switched into multiple flows, comprising: a first seal arranged so as to run around the circumference of a side plate of the vane cell pump; a second seal arranged so as to run around a shaft leadthrough provided in the side plate; and a third seal which, apart from at least one first fluid connection, shuts off at least a second fluid connection with respect to the at least one first fluid connection within a region which is located between the first seal and the second seal.

2. The seal arrangement according to claim 1, wherein the first seal is a radial seal.

3. The seal arrangement according to claim 1, wherein the first seal is an O-ring.

4. The seal arrangement according to claim 1, wherein the second seal is an axial seal.

5. The seal arrangement according to claim 4, wherein the second seal is a shaped seal.

6. The seal arrangement according to claim 1, wherein the third seal is an axial seal.

7. The seal arrangement according to claim 6, wherein the third seal is a shaped seal.

8. The seal arrangement according to claim 1, wherein the third seal has a first part which shuts off at least one second fluid connection with respect to at least a first fluid connection, and a second part which seals at least one second fluid connection with respect to the shaft leadthrough.

9. The seal arrangement according to claim 8, wherein the third seal and the second seal are formed by a common seal element or included by a common seal element, or forming a common seal element.

10. The seal arrangement according to claim 1, wherein a spring element is arranged, or an installation space for a spring element is kept clear, in the region which is located between the first seal and the second seal.

Description

DRAWINGS

[0021] The invention will be described in greater detail using exemplary embodiments which are shown in the drawing. The proportions of the individual elements with respect to one another in the figures do not always correspond to the real proportions, since some shapes are simplified and other shapes are shown on an enlarged scale in comparison with other elements for improved illustration. Identical reference numerals are used for identical or identically acting elements of the invention. Furthermore, for the sake of clarity, only reference numerals are shown in the individual figures which are required for the description of the respective figure. The embodiments which are shown represent merely examples as to how the invention can be configured, and do not represent a conclusive restriction. In the drawing, in a diagrammatic illustration:

[0022] FIG. 1 shows a first exemplary embodiment of a seal arrangement according to the prior art for a vane cell pump of cartridge design with switchable flows at the same pressure level, in a plan view of its side plate which has the outlets of the flows;

[0023] FIG. 2 shows a second embodiment of a seal arrangement according to the prior art for a vane cell pump of stand-alone design with switchable flows at different pressure levels, in a plan view of its end side which has the outlets of the flows; and

[0024] FIG. 3 shows a seal arrangement for a vane cell pump with switchable flows at different pressure levels, in a plan view of its side plate which has the outlets of the flows, and which is constructed in accordance with the teachings of the present invention.

DETAILED DESCRIPTION

[0025] One or more example embodiments of a sealing arrangement for a pump are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0026] A seal arrangement 10 (shown in full or in parts in FIG. 3) of a vane cell pump 20 of cartridge design is configured such that it can be switched into multiple flows, for example, in a manner which is dependent on temperature, comprises: a first seal 11 arranged so as to run around the circumference of a side plate 21, preferably the pressure plate of the vane cell pump 20; a second seal 12 arranged so as to run around a shaft leadthrough 22 provided in the same side plate 21 of the vane cell pump 20 for a drive shaft which can be connected or is connected to a rotor of the vane cell pump 20; and a third seal 14 which, apart from at least one first or remaining fluid connection 23 which forms an outlet of a first or remaining flow of the vane cell pump 20, shuts off at least a second fluid connection 24 which forms an outlet of at least one second flow of the vane cell pump 20 and is provided in or on the side plate 21 of the vane cell pump 20, with respect to the at least one first or remaining fluid connection 23 within a region 13 which is configured between the first seal 11 and the second seal 12.

[0027] The region 13 which is at the same primary pressure p.sub.1 as that flow of the vane cell pump 20 and which opens by way of the at least one first or remaining fluid connection 23 is sealed with respect to an ambient pressure p.sub.0 which prevails in a surrounding area by means of the first seal 11 of the seal arrangement 10.

[0028] The region 13 which is at the same primary pressure p.sub.1 as that flow of the vane cell pump 20 and which opens by way of the at least one first or remaining fluid connection 23 is sealed with respect to the shaft leadthrough 22 and the ambient pressure p.sub.0 which likewise prevails there by means of the second seal 12 of the seal arrangement 10.

[0029] The third seal 14 seals at least one second fluid connection 24, into which a second or further flow of the vane cell pump 20 opens, which second or further flow delivers at a secondary pressure p.sub.2, preferably not directly with respect to the ambient pressure p.sub.0, but rather shuts it off with respect to the region 13 which is at the primary pressure p.sub.1.

[0030] The first seal 11 is preferably a radial seal or comprises a seal of this type. The first seal 11 is with preference an O-ring or it comprises a seal of this type. The second seal 12 is preferably an axial seal or comprises a seal of this type. The second seal 12 is, for example, a shaped seal or it comprises a seal of this type. The third seal 14 is preferably an axial seal or it comprises a seal of this type. The third seal 14 is, for example, a shaped seal or it comprises a seal of this type. The third seal 14 particularly preferably has a (for example) first part 141 which shuts off at least one second or further fluid connection 24 with respect to at least one first or remaining fluid connection 23.

[0031] In the seal arrangement 10 which is shown in FIG. 3, the at least one first or remaining fluid connection 23 opens into the region 13, with respect to which the (for example) first part 141 of the third seal 14 shuts off the second or further fluid connection 24.

[0032] Moreover, the third seal 14 can have a further (for example) second part 142 which seals at least one second or further fluid connection 24 with respect to the shaft leadthrough 22 and the ambient pressure p.sub.0 which prevails there.

[0033] In the seal arrangement 10 which is shown in FIG. 3, the third seal 14 adjoins the second seal 12 directly. It is conceivable here that a part of the second seal 12 which adjoins the third seal 14 belongs to the third seal 14 and forms the addressed further part 142. In this case, in an embodiment of the seal arrangement 10 according to FIG. 3, the second seal 12 would not lead completely around the shaft leadthrough 22, but rather only around part of the shaft leadthrough 22. The remaining part of the circumference of the shaft leadthrough 22 which is not assumed by the second seal 12 would be assumed by the further (for example) second part 142 of the third seal 14.

[0034] One advantageous embodiment of the seal arrangement 10 provides that the third seal 14 and the second seal 12 are formed by a common seal element or are included by a common seal element, or form or comprise a common seal element.

[0035] It can be seen that the invention can be realized by way of a vane cell pump 20 of cartridge design which is equipped with a corresponding seal arrangement 10.

[0036] A captive securing mechanism or arrangement can be provided in order that the side plate 21, which preferably forms the pressure plate, cannot be detached from the pump during mounting and handling. A captive securing mechanism or arrangement for that side plate 21 of the vane cell pump 20 which is provided with the seal arrangement 10 can be realized by way of a circlip on a drive shaft which is guided through the shaft leadthrough 22 and can be connected or is connected to a rotor of the vane cell pump 20, for example by way of a securing element which is arranged on the drive shaft in the form of a securing ring which is also called a groove ring and is better known under the designation Seeger ring. The side plate 21 is preferably the pressure plate of the vane cell pump 20.

[0037] The second seal 12 can be guided around a projection 25 which is provided on the side plate 21 and fixes, for example clamps, the second seal in a frictionally locking and/or positively locking manner around the whole shaft leadthrough 22.

[0038] A spring element 26 can be arranged or an installation space for a spring element 26 can be kept clear in the region 13 which is configured between the first seal 11 and the second seal 12 and is at the primary pressure p.sub.1 which is different from the delivery pressure of the second flow which corresponds to the secondary pressure p.sub.2, which spring element 26 prestresses the side plate 21 axially against a contour ring of the vane cell pump 20 of cartridge design.

[0039] A spring element 26 of this type can be provided to exert a sufficiently great axial force in the closing direction on the side plate 21, for over-compression of the vane cell pump 20.

[0040] A first fluid connection 23 (also called a primary outlet) of a first flow of the vane cell pump 20 and a second fluid connection 24 (also called a secondary outlet) of a second flow of the vane cell pump 20 are preferably provided in the side plate 21. Both the first fluid connection 23 and the second fluid connection 24 open within the first seal 11 which surrounds the outer circumference of the side plate 21 and outside the second seal 12 which surrounds the shaft leadthrough 22 in the side plate 21.

[0041] In order for it to be possible to not only switch the two flows of the vane cell pump 20 of cartridge design separately, but rather also for it to be possible to operate them at a different pressure level, the second fluid connection 24, into which the second flow of the vane cell pump 20 opens, is separated by way of the third seal 14 from the region 13 which is at primary pressure p.sub.1 and comprises the first fluid connection 23, into which the first flow of the vane cell pump 20 opens. As a result, the two flows can be operated at different pressure levels. Moreover, the first fluid connection 23 and the second fluid connection 24 provide axial outlets which are advantageous for the cartridge design for the two flows at a different pressure level in the pressure plate region.

[0042] The three pressure levels ambient pressure p.sub.0, primary pressure p.sub.1 of the first flow, secondary pressure p.sub.2 of the second flow are separated from one another by the seal arrangement 10 by way of its first seal 11, second seal 12 and third seal 14.

[0043] It is important to highlight that the seal arrangement must not be detached from the pump during mounting and handling. Accordingly, an abovementioned captive securing mechanism or arrangement can be provided for the side plate 21 which is configured, for example, as a pressure plate, by way of which captive securing means not only the side plate 21, but rather also the first seal which is configured, for example, as a radial seal, for example as an O-ring, and is preferably arranged on the circumference of the side plate 21, for example in a circumferential groove which is provided on a circumferential face, are secured.

[0044] For example, a common seal element which forms or comprises the second seal 12 and the third seal 14 can be fixed for securing against loss in a positively locking manner on a projection 25 which is provided on the side plate 21 and surrounds the shaft leadthrough 22. The said projection 25 can have, for example, a circumferential undercut, the shape of which replicates the seal element and thus engages into it. As an alternative or in addition, a corresponding projection, optionally likewise with a (for example) circumferential undercut, can be configured so as to run around the second fluid connection 24. In the case where corresponding projections 25 are configured both around the shaft leadthrough 2 and around the second fluid connection, a common seal element can additionally be clamped between the two projections in the region of the part 142. Fluid connections of the corresponding side which form the oil passages can be situated at any desired position. The installation space is unchanged with respect to the prior art.

[0045] It can be seen that the invention can be realized by way of a seal of three pressure levels by means of O-ring radially and axial seal in combination with a captive securing means of the seal arrangement 10 and the side plate 21 which is configured, for example, as a pressure plate, for example by means of a circlip, and the use of a suitable spring element 26 for the axial prestress of the vane cell pump 20.

[0046] The first flow is separated radially from the ambient pressure p.sub.0 by means of the first seal 11 which is configured, for example, as a radial seal, preferably as an O-ring.

[0047] The first flow is preferably separated from the second flow by way of an axial seal, with preference in the form of a common seal element which forms or comprises the second seal 12 and the third seal 14.

[0048] Here, the axial seal is divided into two segments. A first segment which forms the third seal 14 comprises the second fluid connection 24 (also called a secondary passage) of the second flow through the side plate 21 which is configured, for example, as a pressure plate. If the secondary pressure is lowered and in the process the area within that region of the second flow connection 24 which is enclosed by the third seal 14 is kept as small as possible, this aids the over-compression of the vane cell pump 20. Furthermore, in the case of a secondary area which is as small as possible, the primary area which corresponds to the region 13 is as great as possible. This means that the installation space which is available for a spring element 26 in the region 13 likewise becomes as great as possible. One possible embodiment of the spring element 26 is, for example, an open corrugated spring.

[0049] A captive securing mechanism or arrangement which is optionally provided for the side plate 21 (which is configured, for example, as a pressure plate) can be realized by means of a passage of a shaft, preferably a drive shaft of the rotor of the vane cell pump 20 through the side plate 21, and a securing ring which interacts with the shaft. Here, ambient pressure p.sub.0 prevails in the region of the shaft passage 22. The ambient pressure p.sub.0 has to be separated from the primary pressure p.sub.1 and from the secondary pressure p.sub.2.

[0050] A second segment of the axial seal which forms the second seal 12 assumes this task. Clamping of the seal, optionally with an undercut, in the centre of the side plate 21 which is configured, for example, as a pressure plate is possible as a result of the round shape of the second seal segment. The captive securing action of the seal arrangement 10 is ensured as a result. If required, the axial seal can be supplemented by a supporting element.

[0051] Advantages in comparison with the prior art are an optimum utilization of the small amount of installation space which is available for the cartridge design, a simple captive securing means of the pressure plate or side plate 21 and the seal arrangement 10, and a satisfactory over-compression of the vane cell pump 20 in the switched state which represents the critical case.

[0052] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.