Pump stand for vacuum pump

Abstract

To prevent vibrations originating from a vacuum pump, particularly a spare vacuum pump, from being transmitted to a pump stand in a vacuum pump stand, and similarly to prevent external impact from being transmitted to the vacuum pump, particularly the spare vacuum pump, of the pump stand.SOLUTION: A pump stand 10 has a base element 22. The base element 22 is provided with a bearing unit for vibrationally separating a vacuum pump 14 from the pump stand. The bearing unit has a carrier element 16 for at least indirectly supporting the vacuum pump, at least one spring element 20, a mounting element 24 having a shaft part 26, and a spacer sleeve 32.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pump stand for a vacuum pump, in particular for a diaphragm vacuum pump. [Background technology]

[0002] A vacuum pump stand is used to accommodate several vacuum pumps. These vacuum pumps are connected to one another in terms of flow, particularly in series, so that the pressure stages that can be achieved are complementary. For example, a vacuum pump stand may have a diaphragm vacuum pump as an auxiliary vacuum pump and a turbomolecular pump as a high vacuum pump. In this case, if the diaphragm vacuum pump is rigidly attached to the pump stand or the base element of the pump stand for accommodating the diaphragm vacuum pump, vibrations emanating from the diaphragm vacuum pump may be transmitted to the turbomolecular vacuum pump in an undesirable manner during operation of the diaphragm vacuum pump, which may cause malfunctions of the turbomolecular pump.

[0003] Furthermore, during transport of the pump stand, shocks caused by the transport can be transmitted to the pre-vacuum pump, for example configured as a diaphragm vacuum pump or a rotary vane pump, if the pre-vacuum pump is rigidly attached to the pump stand, which can result in damage to the pre-vacuum pump. Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is therefore to ensure that vibrations originating from a vacuum pump, in particular a pre-vacuum pump, in a vacuum pump stand are not transmitted to the pump stand, and that external shocks are not transmitted to the vacuum pump, in particular a pre-vacuum pump, of the pump stand. Furthermore, an additional transport lock for the vacuum pump should not be necessary, which would otherwise have to be released explicitly when the pump stand is started up. [Means for solving the problem]

[0005] This problem is solved by a pump stand having the features of claim 1, in particular in that the pump stand has at least one bearing unit, via which vibration-technical isolation of the vacuum pump from the pump stand can be achieved.

[0006] The bearing unit in this case has a carrier element for supporting the vacuum pump, where the carrier element may for example be a flat plate or one or more support plates for supporting the vacuum pump. Deflection The bearing unit may be a beam. Furthermore, the bearing unit has at least one spring element, for example in the form of a compression coil spring, via which the carrier element is resiliently supported on the base element of the pump stand, so that the spring element extends between the opposing sides of the carrier element and the base element. If the carrier element is, for example, a rectangular carrier plate, the carrier plate may be resiliently supported at its four corners on the base element of the pump stand via the spring elements present therein.

[0007] In order to hold the carrier element on the base element so that it does not get lost and to secure it against lifting forces during transportation of the pump stand, the support unit may further have at least one mounting element, for example in the form of a screw with an axial portion, which extends through the spring element and by means of which the carrier element is fastened to the base element, in particular in which case it may be envisaged that the carrier element is fastened to the base element by means of the mounting element against the preload of the spring element.

[0008] Since at least one spring element should not exert a preload or force on the carrier element in the unloaded state of the support unit, thereby allowing all mounting elements (via which the carrier elements are supported on the base element of the pump stand) to be tightened with the same strength, the support unit further has a spacer sleeve, which is surrounded by the spring element and which itself surrounds the shaft of the mounting element over its extended length, which extends as a result of tightening between the base element and the carrier element.

[0009] The shank of the mounting element, the spacer sleeve, and the spring element are therefore arranged essentially concentrically with one another, with the spacer sleeve having an extension length corresponding to the clamping length of the mounting element, and thus the length of the shank, that extends as a result of the clamping of the carrier element and the base element. In other words, the length of the spacer sleeve corresponds to the portion of the shank that extends as a result of the clamping of the carrier element and the base element. For this purpose, the axial length of the spacer sleeve must be selected so that the shank of the mounting element is already clamped in the unloaded state of the bearing unit. Similarly, the axial length of the spacer sleeve should be adjusted to the axial extension length of the spring element so that the spring element does not exert a force or preload in the unloaded state of the bearing unit, i.e., when there is no vacuum pump on the carrier element.

[0010] The spacer sleeve thus sets the mutual distance between the carrier element and the base element in the unloaded state of the bearing unit, which likewise ensures that the spring element does not exert a preload on the unloaded state of the bearing unit, i.e., the mounting element can be tightened until a predetermined distance between the carrier element and the base element is achieved.

[0011] Preferred embodiments of the invention are described below, further embodiments may be apparent from the dependent claims, the description of the drawings and the drawings themselves.

[0012] Thus, according to one embodiment, at least one guide for the spring element is formed on the carrier element and / or the base element, which ensures that the spring element is compressed purely axially during pump operation. The guide thus prevents any possible lateral displacement of the spring element. Likewise, such a guide serves as a positioning fixture for the spring element, ensuring that the spring element maintains its concentric position relative to the mounting element and the spacer sleeve surrounding the shank of the mounting element. This prevents the spring element from coming into contact with the spacer sleeve, which could otherwise result in undesirable rattle noise during vacuum pump operation.

[0013] According to one embodiment, the guide referred to here may be, for example, a dome formed on the base element and / or carrier element, which is surrounded by the spring element and against which the respective ends of the spacer sleeves rest, in which case it may be envisaged in particular that the end of the shank of the mounting element is threaded into the dome, so that a hollow space with a corresponding internal thread is formed in the dome.

[0014] Since the spring elements surround the dome, fixing the radial positioning of the spring elements relative to the spacer sleeves that rest on the domes, the spring elements desirably do not contact the spacer sleeves, which could otherwise cause undesirable rattle noises.

[0015] Additionally or alternatively to the above-described embodiments, the guides may be recesses in the form of blind holes formed in the base element and / or carrier element, which recesses receive respective ends of the spring elements, again preventing misalignment of the spring elements with respect to the spacer sleeve and thereby preventing undesirable rattle noises that might otherwise occur when the spring elements abut against the spacer sleeve.

[0016] According to yet another embodiment, a dome is formed on the base element for guiding the spacer sleeve, the dome being surrounded by the spring element and on which one end of the spacer sleeve stands, while a corresponding recess is formed in the carrier element, which recess receives the other end of the spring element. However, alternatively, the dome can be formed in the carrier element and the recess in the base element.

[0017] According to yet another embodiment, it may be envisaged that the spacer sleeve is manufactured from a plastic material, since this ensures that even if contact occurs between the spring element and the spacer element when the vibrations are not strictly axial, this will not cause undesirable rattle noises. Similarly, the spacer sleeve being made from a plastic material prevents undesirable rattle noises due to contact between the spacer sleeve and the shank of the mounting element and the carrier element. Constructing the spacer sleeve from a plastic material may prove advantageous when no guide for the spring element is provided, since in this case undesirable rattle noises will be prevented even if the spring element and the spacer sleeve come into contact.

[0018] As already briefly mentioned above, the carrier element can be, for example, a carrier plate on which a vacuum pump can be mounted. Alternatively, according to another embodiment, the carrier element can comprise at least one Deflectionhaving a beam, Deflection The beams are supported at one end by the base element via spring elements, and the shafts of the spring elements, which extend through the spacer sleeves, are fastened to the base element by the mounting elements. Deflection The beam is supported at both ends by the bearing units as described above. Deflection The beam forms a simple beam in the static sense. Preferably, the carrier element comprises two such beams extending substantially parallel to each other. Deflection In this case, two beams Deflection A vacuum pump may be mounted on the beam, and the vacuum pump may comprise two Deflection It bridges the gap between the beams. Deflection The beams are vibrationally separated from each other, so that Deflection The deflection of the beam Deflection It has no effect on the deflection of the beam and vice versa.

[0019] For example, in order to prevent even very large displacements of the spring elements from being transmitted to the pump stand, according to a preferred embodiment it can be envisaged that each spring element of each support unit has a spring constant selected to a value such that the spring elements do not come into contact with each other during operation of the vacuum pump.

[0020] In order to provide vibration-technical isolation between the vacuum pump and the pump stand in both the vertical and horizontal directions, according to another embodiment, it can further be envisaged that the pump stand has at least two support units, the spring elements, spacer sleeves and mounting elements of the support units being oriented perpendicular to each other.

[0021] The invention will now be described, by way of example only, with reference to the drawings in which: [Brief explanation of the drawings]

[0022] [Figure 1] 1 shows a portion of a pump stand according to the present invention from one viewing direction. [Figure 2]1 shows a first embodiment of a bearing unit according to the invention; [Figure 3] 2 shows a second embodiment of a bearing unit according to the invention; [Figure 4] 3 shows a third embodiment of a bearing unit according to the invention. [Figure 5] 4 shows a fourth embodiment of a bearing unit according to the invention. [Figure 6] 1 shows an embodiment with two bearing units oriented perpendicular to each other. DETAILED DESCRIPTION OF THE INVENTION

[0023] Figure 1 shows part of a pump stand 10 according to the invention from one viewing angle. In particular, Figure 1 shows part of the housing 12 of the pump stand 10. A pre-vacuum pump 14 in the form of a diaphragm vacuum pump is accommodated in the housing 12. A high vacuum pump, for example in the form of a turbomolecular pump, supported by the pump stand 10, in particular by the housing 12 of the pump stand 10, is not shown. The high vacuum pump is connected upstream of the pre-vacuum pump 14 in the flow direction.

[0024] As can be seen from Figure 1, the auxiliary vacuum pump 14 is located on a carrier element 16, which may be a carrier plate on which the auxiliary vacuum pump 14 stands. Alternatively, the carrier element 16 may be two parallel plates extending parallel to each other and spaced apart perpendicular to the plane of the drawing. Deflection beam 18; Deflection On the beam 18, a pre-vacuum pump 14 is installed. Deflection It is mounted to bridge the gap between the beams 18.

[0025] As can be seen from Figure 1, each DeflectionThe beam 18 is elastically supported at both ends by spring elements 20 on a base element 22 of the housing 12, thereby preventing vibrations caused by the operation of the pre-vacuum pump 14 from being transmitted to the housing 12 and from there to a turbomolecular vacuum pump (not shown) supported in the housing 12.

[0026] As can be seen from the enlarged view of FIG. Deflection The beam 18 is supported on the base element 22 via a spring element 20 in the form of a compression coil spring 20, so that the spring element 20 extends between two facing faces of the carrier element 16 and the base element 22. DeflectionTo be able to secure the beam 18, the carrier element 16 is fastened to the base element 22 by means of a fastening element 24 in the form of a bolt 24, the shank 26 of which extends through the compression spring 20. To fasten the carrier element 16 to the base element 22, the free end of the shank 26 of the bolt 24 can be threaded into an internal thread formed in the base element 22 or into a nut located below and against the base element 22. In the illustrated embodiment, the screw head 28, on the other hand, abuts against the upper surface of the carrier element 16 via a washer 30, so that the carrier element 16 is secured to the base element 22 against lifting forces. However, the washer 30 is not necessarily required if the hole 34 in the carrier element 16 is too small for the screw head 28 to pass through or if flange-head screws are used. The mounting element 24 therefore provides a transport lock that prevents the carrier element 16 from bouncing off the spring element 20 during transport of the pump stand 10. A separate transport lock is therefore not required, with which the carrier element 16 can be fastened to the base element 22 for transport until the spring element 20 is tightly attached. In the case of such a separate transport lock, it may happen that the transport lock is forgotten to be released after transport, which could lead to undesirable vibration transmission to the high-vacuum pump during operation. The mounting element 24 of the bearing unit according to the invention therefore does not need to be removed after transport of the pump stand 10, thereby providing a transport lock that is less prone to misuse.

[0027] Since the preload starting from the spring element 20 becomes large enough that the carrier element 16 is tightened to the base element 22 by the mounting element 24, the shank 26 of the mounting element 24 is surrounded by a spacer sleeve 32. The spacer sleeve 32 may preferably be made of a plastic material. In this case, the spacer sleeve 32 specifically extends between the underside of the washer 30 and the side of the base element 22 facing the carrier element 16. In particular, the spacer sleeve 32 extends through an opening 34 formed in the carrier element 16, through which the shank 26 of the mounting element 24 also extends. The axial extension of the spacer sleeve 32 therefore sets the maximum distance between the carrier element 16 and the base element 22. This ensures that the mounting element 24 can be tightened precisely until the spring element 20 exerts a predetermined amount of preload force.

[0028] The axial extension of the spacer sleeve 32 therefore sets the length of the threaded shank 26 that will stretch under stress, since the spacer sleeve 32 extends between the underside of the washer 30 and the side of the base element 22 facing the carrier element 16. The length of the threaded shank that will stretch under stress is usually called the clamping length, which in technical mechanics means the thickness of the parts to be joined, including any washers that may be present.

[0029] In this case, the axial length of the spacer sleeve 32 should be selected so that, in the unloaded state of the bearing unit, when the pump is not yet placed on the carrier element 16, the spring element 20 exerts no preload and therefore the shank 26 of the mounting element 24 is clamped exclusively by the clamping moment of the mounting element 24. In contrast, the spring constant of the spring element 20 should be selected so that the spring element 20 does not stick even during operation of the auxiliary vacuum pump mounted on the carrier element 16.

[0030] As mentioned above, it is recommended that the spacer sleeve 32 be made from a plastic material, as this ensures that no undesirable rattle noises occur when the spring element 20 and the spacer sleeve 32 come into contact.

[0031] However, in order to preclude such contact between the spring element 20 and the spacer sleeve 32 from the outset, the embodiment shown in Figure 3 envisages that the carrier element 16 is formed with a hollow cylindrical recess 36 on its side facing the base element 22, which recess 36 receives the corresponding end of the spring element 20 and is coaxially aligned with the opening 34 in the carrier element 16. The spring element 20 is thus held radially in the recess 36, which ensures that the coaxial arrangement of the spring element 20, the spacer sleeve 32 and the mounting element 24 is permanently maintained.

[0032] As an alternative to the embodiment shown in Fig. 3, the embodiment shown in Fig. 4 provides for a dome 38 in the form of a hollow cylindrical protuberance formed on the side of the base element 22 facing the carrier element 16, the compression spring 20 then surrounding the dome 38 and thus radially holding it in place. Furthermore, in the embodiment shown in Fig. 4, the lower end of the spacer sleeve 32, again made of plastic material, stands on the dome 38. This means that the length of the stem 26 of the mounting element 24 that expands as a result of tightening the carrier element 20 with the base element 22 and the axial extension height of the dome 38 are smaller than in the embodiment of Fig. 2.

[0033] In the embodiment of Figure 4, the dome 38 is provided with an internal thread (not shown) into which the free end of the shank 26 is threaded, whereas alternatively the dome 38 may only define a through opening through which the shank 26 extends, in which case a nut may be provided below the base element 22 or above the carrier element 16 that abuts against the base element 22 or carrier element 16, and into which the free end of the shank 26 is threaded.

[0034] The embodiment of Figure 5 is in some sense a combination of the embodiment of Figure 3 and the embodiment of Figure 4, since according to the embodiment of Figure 5 the base element 22 is formed with a dome 38 and the carrier element 16 is formed with a recess 36 for securing the respective spring end.

[0035] Thus, the aforementioned bearing unit can provide a vibration-technical decoupling between the vacuum pump 14 and the pump stand 10 in the vertical direction. In order to also be able to suppress or at least damp horizontal pump vibrations, the carrier element 16 according to the embodiment shown in FIG. 6 has an angled cross section. Deflection A beam 18 in which vertical angle legs 40 are secured to a vertical base element portion 22' in a manner corresponding to the horizontal angle legs for a support unit consisting of a spring element 20, a spacer sleeve 32 and a mounting element 24. The present application relates to the invention described in the claims, but also includes the following as other aspects. 1. A pump stand (10) for a vacuum pump (14), in particular an auxiliary vacuum pump, comprising: the pump stand (10) has a base element (22) on which a bearing unit is provided for vibrationally isolating the vacuum pump (14), in particular the auxiliary vacuum pump, from the pump stand (10), The support unit comprises: a carrier element (16) for at least indirectly supporting the vacuum pump (14); at least one spring element (20) via which the carrier element (16) is supported on the base element (22), so that the spring element (20) extends between the opposing sides of the carrier element (16) and the base element (22); a mounting element (24), in particular in the form of a screw, having a shank (26), by means of which the carrier element (16) is fastened to the base element (22); a spacer sleeve (32) that is surrounded by the spring element (20) and that itself surrounds the shank (26) of the mounting element (24) over an extended length that extends as a result of the clamping of the base element (22) and the carrier element (16); A pump stand (10). 2. The pump stand (10) of claim 1, wherein the axial length of the spacer sleeve (32) is selected to be such that, when the support unit is in an unloaded state, the shaft portion (26) of the mounting element (24) is tightened solely based on the tightening moment of the mounting element (24). 3. 3. The pump stand (10) of claim 1 or 2, wherein the spring element (20) receives only the load of the carrier element (16) when the support unit is in an unloaded state. 4. 4. The pump stand (10) according to any one of 1 to 3 above, wherein the spring element (20) is a compression coil spring (20). 5. 5. The pump stand (10) according to any one of 1 to 4 above, wherein the carrier element (16) and / or the base element (22) are formed with at least one guide for the spring element (20). 6. the guide is a dome (38) formed on the base element (22) and / or the carrier element (16), the spring element (20) surrounds the dome (38) and the end of the spacer sleeve (32) stands on the dome (38); In particular, the pump stand (10) of claim 5, wherein the stem (26) of the mounting element (24) is threaded into the dome (38). 7. The pump stand (10) of claim 5, wherein the guide is a recess (36) formed in the base element (22) and / or the carrier element (16), and the recess (36) accommodates each end of the spring element (20). 8. 8. The pump stand (10) according to any one of 1 to 7 above, wherein the spacer sleeve (32) is made of a plastic material. 9. The carrier element (16) comprises at least one Deflection A beam (18) is provided. Deflection 9. A pump stand (10) according to any one of 1 to 8 above, wherein the beam (18) is supported at multiple ends on the base element (22) via one of the spring elements (20) each, and is fastened to the base element (22) by an attachment element (24), the shaft portion (26) of the attachment element (24) extending through the spacer sleeve (32). 10. The carrier element (16) is made up of two parallel-extending Deflection The pump stand (10) of claim 9, having a beam (18). 11. The two aforementioned Deflection On the beam (18), the two Deflection The pump stand (10) as described above, on which a vacuum pump (14), in particular a diaphragm vacuum pump (14) or a rotary vane pump, is mounted, bridging the gap between the beams (18). 12. 12. The pump stand (10) of any one of 1 to 11 above, wherein the spring element (20) has a spring constant selected so that the spring element (20) does not seal during operation of the vacuum pump (14). 13. The pump stand (10) of any one of 1 to 12 above, wherein the pump stand (10) has at least two support units, the spring elements, spacer sleeves (32) and mounting elements (24) of which are oriented perpendicular to each other. [Explanation of symbols]

[0036] 10 Pump Stand 12 Housing 14 Auxiliary vacuum pump 16 Career Elements 18 Deflection beam 20 Spring Elements 22 Base Elements 22' base element part 24 Mounting elements / threaded bolts 26 Shaft 28 screw head 30 washer 32 Spacer sleeve 34 Aperture 36 Recess 38 Dome 40 Vertical angle leg piece 42 Horizontal angle leg piece

Claims

1. A pump stand (10) for a vacuum pump (14), comprising: the pump stand (10) has a base element (22) on which a bearing unit is provided for vibrationally isolating the vacuum pump (14) from the pump stand (10), The support unit comprises: a carrier element (16) for at least indirectly supporting the vacuum pump (14); at least one spring element (20) via which the carrier element (16) is supported on the base element (22), so that the spring element (20) extends between the opposing sides of the carrier element (16) and the base element (22); a mounting element (24) having a stem (26), by means of which the carrier element (16) is fastened to the base element (22); a spacer sleeve (32) that is surrounded by the spring element (20) and that itself surrounds the stem (26) of the mounting element (24) over an extension length that extends as a result of the clamping of the base element (22) and the carrier element (16); and The carrier element (16) has at least one flexible beam (18), the flexible beam (18) being supported at a plurality of ends on the base element (22) via one of the spring elements (20) each, and fastened to the base element (22) by mounting elements (24), the shank (26) of the mounting element (24) extending through the spacer sleeve (32). Pump stand (10).

2. 2. A pump stand (10) as described in claim 1, wherein the axial length of the spacer sleeve (32) is selected to be such that, in the unloaded state of the bearing unit, the shaft portion (26) of the mounting element (24) is tightened solely based on the tightening moment of the mounting element (24).

3. 3. A pump stand (10) according to claim 1 or 2, wherein the spring element (20) is only subjected to the load of the carrier element (16) in the unloaded state of the bearing unit.

4. 3. The pump stand (10) according to claim 1 or 2, wherein the spring element (20) is a compression coil spring (20).

5. 3. Pump stand (10) according to claim 1 or 2, wherein the carrier element (16) and / or the base element (22) are formed with at least one guide for the spring element (20).

6. the guide is a dome (38) formed on the base element (22) and / or the carrier element (16), the dome (38) is surrounded by the spring element (20) and an end of the spacer sleeve (32) stands on the dome (38), 6. The pump stand (10) of claim 5, wherein the stem (26) of the mounting element (24) is intended to be threaded into the dome (38).

7. 6. A pump stand (10) as described in claim 5, wherein the guide is a recess (36) formed in the base element (22) and / or the carrier element (16), the recess (36) accommodating one end of the spring element (20).

8. 3. The pump stand (10) according to claim 1 or 2, wherein the spacer sleeve (32) is made from a plastic material.

9. 2. The pump stand (10) of claim 1, wherein the carrier element (16) has two flexible beams (18) extending parallel to each other.

10. 10. A pump stand (10) according to claim 9, wherein a vacuum pump (14) is mounted on the two flexible beams (18) and bridges the gap between the two flexible beams (18).

11. 3. The pump stand (10) of claim 1 or 2, wherein the spring element (20) has a spring constant selected so that the spring element (20) does not seal during operation of the vacuum pump (14).

12. The pump stand (10) according to claim 1 or 2, wherein the pump stand (10) has at least two bearing units, the spring elements, spacer sleeves (32) and mounting elements (24) of which are oriented perpendicular to each other.

13. A pump stand (10) as described in claim 1, wherein the vacuum pump (14) is an auxiliary vacuum pump.

14. A pump stand (10) as described in claim 1, wherein the mounting element (24) is a screw.

15. A pump stand (10) as described in claim 10, wherein the vacuum pump (14) is a diaphragm vacuum pump or a rotary vane pump.

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