SCREW COMPRESSOR HAVING ROTORS MOUNTED ON ONE SIDE

Abstract

The invention relates to a screw compressor for compressing a medium, having a drive unit (01) which has a drive (06, 07), and having a compressor unit (03) which has two mutually engaging rotors (21, 22) with screw profiles, which are complementary to one another, and a compressor housing (19) having an inlet (24) and an outlet (23). The rotors (21, 22) are coupled to the drive unit via a shaft (10, 14) in each case. The shafts (10, 14) are only mounted on the drive side of the rotors (21, 22). The rotors (21, 22) are mounted only on one side relative to their axial direction and are not mounted on their side which faces axially away from the drive (06, 07).

The invention furthermore relates to a screw compressor arrangement with screw compressors which are fluidically connected in series.

Claims

1. A screw compressor for compressing a medium, having a drive unit (01) which has a drive (06, 07), and having a compressor unit (03) which has two mutually engaging rotors (21, 22) with screw profiles, which are complementary to one another, and a compressor housing (19) having an inlet (24) and an outlet (23), wherein the rotors (21, 22) are coupled to the drive unit via a shaft (10, 14) in each case, and wherein the shafts are rotatably mounted, characterised in that the shafts (10, 14) are mounted only on the drive side of the rotors (21, 22), wherein the rotors (21, 22) are mounted only on one side relative to their axial direction and are not mounted on their side which faces axially away from the drive (06, 07).

2. The screw compressor according to claim 1, characterised in that the screw profiles are configured to convey the medium to be compressed from that side of the rotors which faces the drive in the direction towards the side facing away from the drive when the rotors (21, 22) are rotated.

3. The screw compressor according to claim 2, characterised in that the pressure side of the compressor housing (19) is situated on that side of the rotors which faces away from the drive, and has the outlet (23).

4. The screw compressor according to any one of claims 1 to 3, characterised in that each of the shafts (10, 14) is mounted in the drive unit (01) in at least two axially spaced-apart bearings.

5. The screw compressor according to any one of claims 1 to 4, characterised in that the shafts (10, 14) are mounted in spindle bearings.

6. The screw compressor according to any one of claims 1 to 5, characterised in that the drive unit (01) and the compressor unit (03) each have channels which carry cooling agent.

7. The screw compressor according to any one of claims 1 to 6, characterised in that the drive unit (01) has a bearing unit (02) which is situated between the drive and the compressor unit (03), wherein the shafts (10, 14) run through the bearing unit (02) and bearings (11, 12; 15, 14) positioned there and extend into the compressor unit (03).

8. The screw compressor according to any one of claims 1 to 7, characterised in that the ends of the shafts (10, 14) extending out of the drive unit (01) are fixed in coaxially running bores of the rotors (21, 22) in a rotationally secure manner.

9. The screw compressor according to any one of claims 1 to 8, characterised in that the length:diameter ratio of the rotors (21, 22) is in the range from 0.2 to 1.2.

10. The screw compressor arrangement with screw compressors which, in technical flow terms, are connected in series, wherein a first screw compressor functions as a low-pressure stage and is coupled by its pressure side to the suction side of a second screw compressor, which functions as a high-pressure stage, characterised in that the first and the second screw compressors are each constructed in accordance with any one of claims 1 to 9.

Description

[0019] Further advantages, details and developments of the invention emerge from the following description of a preferred embodiment of a screw compressor with reference to the drawings. In the drawings:

[0020] FIG. 1 shows a perspective overall view of a screw compressor according to the invention;

[0021] FIG. 2 shows a cross-sectional view of the screw compressor according to FIG. 1.

[0022] FIG. 1 shows an embodiment, by way of example, of a screw compressor according to the invention in a simplified perspective view from the outside, while the details in FIG. 2 are depicted in a cross-sectional view.

[0023] The screw compressor has a drive unit 01, a bearing unit 02 functionally linked to this, and a compressor unit 03. The bearing unit 02 is situated, when viewed in the axial direction, between the drive unit 01 and the compressor unit 03. These cited units are preferably constructed modularly so that they can be put together in a way which is adapted to the relevant application. In particular, however, the drive unit 01 and the bearing unit 02 may also be configured as a structural unit.

[0024] The drive unit 01 has a drive housing 05, in which an electrical direct drive with an internally situated drive rotor 06 and an externally situated drive stator 07 are arranged. Furthermore, an external drive cooling jacket 08 is provided with cooling channels through which a cooling agent flows. The drive rotor 06 is connected to a first shaft 10 in order to cause the shaft 10 to rotate. The first shaft 10 is mounted in a first bearing, for example a spindle bearing 11, which is situated axially proximate to the drive rotor 06, and in a second bearing, for example a spindle bearing 12, which is situated in the bearing unit 02.

[0025] The drive unit 01 furthermore comprises a second shaft 14 which runs axially parallel to the first shaft 10 and is mounted in a third bearing, for example a spindle bearing 15, in the drive unit 01 and in a fourth bearing, for example a spindle bearing 16, situated in the bearing unit 02. Furthermore, the drive unit 01, preferably in the region of the bearing unit 02, has two gearwheels 17 which are attached to the first and second shafts respectively and serve to synchronously drive the second shaft. The two shafts 10, 14 can preferably be made of tempered steel. The shafts are guided into the compressor unit 03 through seals 18.

[0026] The compressor unit 03 has a compressor housing 19 with a preferably easy-to-open housing lid 20 on the axial end face facing away from the bearing unit 02. Inside the compressor housing 19, there are situated a main rotor 21 and a subsidiary rotor 22 which are positioned axially parallel to one another and bear mutually complementary, mutually engaging screw profiles. The rotors remain easily accessible for maintenance purposes, via the housing lid which is intended to be opened. The two rotors 21, 22 can, for example, consist of ceramic material, carbon or steel and do not have to be manufactured out of the same material as the shafts 10, 14, which expands the areas of application of the screw compressor.

[0027] The first shaft 10 engages by its free end in a coaxial bore of the main rotor 21, while the second shaft 14 engages by its free end in a coaxial bore of the subsidiary rotor 22. The shafts 10, 14 thus drive the rotors 21, 22. The rotors 21, 22 are not mounted on the side of the rotors 21, 22 facing the housing lid 20. Between the end faces of the rotors 21, 22 and the inside of the housing lid 20, a pressure chamber in which the rotors 21, 22 convey the medium when they are rotated is formed. The housing lid 20 has an outlet 23 at which the medium is discharged. Furthermore, at the compressor housing 19, there is provided an inlet 24 via which the medium is sucked in. Through the dimensioning of the outlet 23, it is possible to set the pressure to be achieved on the pressure side of the screw compressor. If the screw compressor is to be adapted to a changed application, for example, the housing lid can be exchanged, with a changed outlet being provided in order to adapt the outlet pressure provided by the screw compressor.

[0028] Finally, the compressor unit 03 has a compressor cooling jacket 25 which in turn comprises cooling channels in which the cooling agent flows. Preferably, cooling channels 26 which carry cooling agent and which are preferred components of the compressor cooling jacket 25 also continue in the housing lid 20. In this manner, the pressure chamber, which is formed on the pressure side of the rotors, can be cooled efficiently.

REFERENCE NUMBERS

[0029] 01—drive unit

[0030] 02—bearing unit

[0031] 03—compressor unit

[0032] 04—

[0033] 05—drive housing

[0034] 06—drive rotor

[0035] 07—drive stator

[0036] 08—drive cooling jacket

[0037] 09—

[0038] 10—first shaft

[0039] 11—first spindle bearing

[0040] 12—second spindle bearing

[0041] 13 —

[0042] 14—second shaft

[0043] 15—third spindle bearing

[0044] 16—fourth spindle bearing

[0045] 17—gearwheels

[0046] 18—seals

[0047] 19—compressor housing

[0048] 20—housing cover

[0049] 21—main rotor

[0050] 22—subsidiary rotor

[0051] 23—outlet

[0052] 24—inlet

[0053] 25—compressor cooling jacket

[0054] 26—cooling channels