GUIDE DEVICE, COOLANT DUCT AND DIFFUSION VACUUM PUMP

Abstract

A guide device for a diffusion vacuum pump having a plurality of annular guide plates. The guide plates being arranged radially, wherein at least one guide plate has a first section starting from a connection point and a second section starting from the connection point. Therein, the first section extends axially in a first direction, the second section extending axially in the opposite second direction. Therein the first section is designed to taper radially and/or the second section is designed to taper radially.

Claims

1. A guide device for a diffusion vacuum pump having a plurality of annular guide plates, the guide plates being arranged radially, wherein at least one guide plate has a first section starting from a connection point and a second section starting from the connection point, wherein the first section extends axially in a first direction, the second section extending axially in the opposite second direction, wherein the first section is designed to taper radially and/or wherein the second section is designed to taper radially.

2. The guide device according to claim 1, characterized in that all guide plates are designed in the same way.

3. The guide device according to claim 1, characterized in that an axial end point of one of the guide plates is located radially above or further inside the connection point of the directly adjacent guide plate.

4. The guide device according to claim 1, characterized in that 3 to 5 guide plates are provided.

5. The guide device according to claim 1, characterized in that at least one guide plate is connected to a cooling element for cooling the guide plate.

6. The guide device according to claim 5, characterized in that the first section and the second section of the at least one cooled guide plate are each formed by a first guide plate element and second guide plate element, wherein the first guide plate element and the second guide plate element are connected to one another by means of the cooling element.

7. The guide device according to claim 6, characterized in that the first guide plate element and/or the second guide plate element of the at least one cooled guide plate have a substantially radially extending section for connection to the cooling element.

8. The guide device according to claim 1, characterized in that the axial length of the second section decreases from an outer guide plate to an inner guide plate.

9. The guide device according to claim 1, characterized in that the guide plates are connected to a flange by means of, in particular, radially extending webs.

10. The guide device according to claim 9, characterized by a coolant duct for supplying the cooling element with a coolant wherein the coolant duct comprises a flange, the flange having a recess with a first diameter, wherein a coolant line is arranged in the recess, the coolant line having a second diameter, the second diameter being smaller than the first diameter so that the coolant line is guided in the recess without contact.

11. A coolant duct for a vacuum pump, in particular a diffusion pump, with a flange, the flange having a recess with a first diameter, wherein a coolant line is arranged in the recess, the coolant line having a second diameter, the second diameter being smaller than the first diameter so that the coolant line is guided in the recess without contact.

12. The coolant duct according to claim 11, characterized in that the coolant line is connected to the flange on the outside of the flange.

13. A diffusion pump having at least one nozzle, wherein a guide device according to claim 1 is arranged directly above the inlet-side nozzle.

14. The diffusion pump according to claim 13, characterized by a coolant duct wherein the coolant duct comprises a flange, the flange having a recess with a first diameter, wherein a coolant line is arranged in the recess, the coolant line having a second diameter, the second diameter being smaller than the first diameter so that the coolant line is guided in the recess without contact.

15. The diffusion vacuum pump according to claim 13, characterized in that there is no contact between the nozzle on the inlet side and the guide device.

16. The diffusion pump according to claim 13, characterized by a connection flange, wherein the flange of the guide device is connected to the connection flange.

Description

BRIEF DESCRIPTION OF TE DRAWINGS

[0032] In the drawings:

[0033] FIG. 1 is a perspective view of the guide device according to the present invention,

[0034] FIG. 2 is a sectional view of the guide device according to FIG. 1,

[0035] FIG. 3 is a view from above of the guide device according to FIG. 1,

[0036] FIG. 4 shows a diffusion vacuum pump according to the present invention and

[0037] FIG. 5 shows a coolant duct according to the present invention.

DETAILED DESCRIPTION

[0038] The guide device 10 according to the invention according to FIG. 1 has a flange 12 by means of which the guide device 10 can be connected to a diffusion vacuum pump 40. In this case, no components protrude beyond the upper side 14 of the flange 12. The components of the guide device 10 are thus arranged below the upper side 14 of the flange 12 and thus protrude into the housing 42 in the diffusion vacuum pump 40. In particular, the guide device 10 does not have its own housing. A particularly compact design is achieved in this way. And the diffusion vacuum pump 40 can thus be connected to a receptacle or a vacuum device by means of the flange 12 of the guide device.

[0039] In the example shown in the figures, the guide device 10 has four guide plates 16 which are arranged radially to one another. The guide plates 16 are connected to the flange 12 of the guide device 10 by means of radial webs 18. The radial webs 18 are only indirectly connected to the flange 12 via thermal insulation elements 20 for thermal separation between the flange 12 and the guide plates 16. A transfer of the cold energy from the guide plates 16 to the flange 12 is thus prevented.

[0040] It can be seen in FIG. 3 that the guide plates 16 have a first section 22 which extends from a common connection point 24 in a first direction 23 or in the direction of the inlet 26 of the guide device. The radius of the first section 22 is reduced starting from the common connection point 24, so that the first section 22 has a smaller radius at its axial end 28 than at the common connection point 24. Likewise, a second section 30 extends in the direction or second direction 31 opposite to the axial direction of extension of the first section 22 or first direction 23. The radius of the second section 30 also decreases starting from the common connection point 24, so that the second section 30 has a smaller radius at the axial end 32 than at the common connection point 24. The first section 22 and the second section 30 are only connected to one another at the common connection point 24. The first section 22 extends in the radial direction so that it lies above the common connection point 34 of the immediately adjacent guide plate 16. The second section 30 also extends so that the axial end 32 of the second section 30 lies radially below the common connection point 34 of the immediately adjacent guide plate 16. This creates an impermeable configuration of the guide device 10, so that oil molecules cannot pass directly through the guide device 10, but always strike a condensation surface and thus cannot enter the receptacle.

[0041] As can be seen on FIG. 3, at the axial end 28, 32 of the first section 22 and/or the second section 30 the guide plates 16 comprise an axially extending section 33. By the axially extending section 33 mechanical stability of the individual guide plates is enhanced. Thus, damage of the guide plates 16 during assembly and disassembly is avoided.

[0042] As can be seen in FIG. 3, the guide plates 16 located further inside have a smaller axial extent of the second section. This ensures that propellant vapor exiting through the nozzle 60 does not collide with the guide plates 16, but can instead be guided unhindered in the conveying direction.

[0043] Furthermore, the first section 22 is indirectly connected to the second section 30 via a cooling element 36, wherein the cooling element 36 is in particular a coolant line. Cooling energy is transferred to the guide plates 16 by means of the cooling element 36 in order to achieve effective condensation of the oil molecules on the condensation surfaces of the guide plates 16. The cooling element 36 is connected to a coolant duct 50. Here, the flange 12 has a recess or depression 52 which is open to the inside. The recess 52 has a first diameter D1. Furthermore, the coolant line 36 has a second diameter D2, wherein the second diameter D2 is smaller than the first diameter D1, so that the coolant line 36 is at least partially guided within the flange 12 without contact. Furthermore, the coolant line 36 is connected to the outside of the flange 12, so that a vacuum-tight connection is created between the coolant line 36 and the flange 12. For example, the coolant line 36 can be connected to the outside of the flange 12 by welding. In this case, the coolant line is guided over the greater part within the recess 52 of the flange 12 without contact and a cold bridge is created only in the area of the weld seam 54. However, this cold bridge has a small cross section, so that a transfer of the cold energy from the coolant line 36 to the flange 12 is reduced. As an alternative or in addition to this, a sealing element (not shown) can be provided at least partially, which is arranged between the flange 12 and the coolant line 36, in particular within the depression or recess 52 of the flange 12. The sealing element consists in particular of plastics material and thus has a lower thermal conductivity than stainless steel or another metal from which the flange 12 is made. The cold energy which is transmitted from the coolant line 36 to the flange 12 is thus reduced. This is because there is a vacuum in the region of the recess 52 and therefore heat transfer does not take place, or only takes place to a small extent, in this region. Of course, the guide device 10 has more than one coolant duct. For example, according to FIG. 2, an inlet 60 and a return 62 for the coolant can be provided, wherein both the inlet 60 and the return 62 are formed as described above and shown in FIG. 5.

[0044] FIG. 4 shows a diffusion vacuum pump according to the present invention. This has a housing 42 and an outlet 41. Furthermore, an inlet 43 of the diffusion vacuum pump 40 is provided and is formed by a flange 44. The flange 12 of the guide device 10 is connected to the flange 44 of the diffusion vacuum pump 40, so that the guide device is arranged completely within the housing 42 of the diffusion vacuum pump 40. Furthermore, the inlet 26 of the guide device 10 forms the inlet of the diffusion vacuum pump 40.

[0045] The diffusion vacuum pump 40 has a storage space 45 for storing a propellant. A heating element is provided in the storage space 45, by means of which the propellant is vaporized and exits again through the nozzles 46. In the process, gas molecules are carried away from the vacuum and conveyed in the direction of the outlet 41. The propellant condenses on the inner walls 47 of the housing 42 and thus returns to the storage space 45.

[0046] The guide device 10 is arranged above the inlet-side nozzle 46, i.e. from the inlet-side nozzle 46 in the direction of the receptacle. There is no contact between the inlet-side nozzle 46 and the guide device 10, so that the cold energy is not transferred from the guide device to the nozzle.

[0047] Thus, a guide device or vapor barrier is created that is integrated into the housing of the diffusion vacuum pump, is nevertheless easy to install and remove again and is completely impermeable. Furthermore, due to the coolant duct according to the invention, it is possible to cool the guide device, even at very low temperatures of down to −196° C., without this having a negative effect on the functionality of the diffusion pump.

[0048] Although elements have been shown or described as separate embodiments above, portions of each embodiment may be combined with all or part of other embodiments described above.

[0049] Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are described as example forms of implementing the claims.