Spiral Compressor

Abstract

A helical compressor capable of improving wear characteristics is presented. [Solution] The present invention relates to a helical compressor having a fixed helical element having a fixed helical wall, a rotating helical element disposed on a rotatable plate and coupled with the fixed helical wall so as to form a number of compression chambers, and a guide means for guiding the rotating helical element and at least two guide pins arranged in a fixed manner.

Description

[Technical field]

[0001] The present invention relates to a helical compressor. [Background technology]

[0002] Helical compressors, also known as scroll compressors, are preferably employed as compressors for cold machines and heat pumps, since they can be mass-produced more cheaply than reciprocating compressors and are less noisy during operation. The conveying effect of a helical compressor is essentially based on two interlocking helical walls, one of which is fixed and the other of which moves eccentrically on a circular path. Due to the eccentric movement of the rotating helical element, in which the rotating helical walls are arranged, several compression working chambers are formed between the interlocking helical walls.

[0003] In known helical compressor designs, a recess with a running sleeve inserted therein is formed on the rear surface of the rotating helical element, called the revolution pocket, which is received on a guide pin, also called the revolution pin, arranged in a fixed manner. When the rotating helical element moves, the running sleeve, also called the revolution ring, rotates about the outer circumferential surface of the guide pin so that it can take up the radial forces that arise during the compressor operation due to the eccentric movement of the rotating helical element. In so doing, the running sleeve protects the inner surface of the recess from increased wear.

[0004] The arrangement of a fixedly arranged guide pin and a recess in the rotating helical element into which a running sleeve is inserted that receives the guide pin can be understood as a guide means for radially guiding the rotating helical element.

[0005] Hitherto, running sleeves have been used that have radial and axial clearances in the recesses so that the running sleeve can move radially and axially in the recesses during operation of the compressor. However, it has also been shown that the clearances, especially in the axial direction, have a detrimental effect on the structural elements axially adjacent to the back surface of the rotating helical element. Therefore, in previously known helical compressors, the structural elements adjacent to the back surface of the rotating helical element (disk-shaped sealing elements for sealing the back surface of the rotating helical element against the housing body) are provided with increased material hardness. The increased material hardness of the disk-shaped sealing elements, also called wear plates, allows to reduce the wear of material on the surface of the disk-shaped sealing elements facing the back surface of the rotating helical element, which in turn reduces the risk of early storage damage and / or blockage of the nozzles of the counterpressure system. However, an increase in the required hardness of the material of the disk-shaped sealing element disposed between the rotating helical element and the housing body of the helical compressor results in increased costs because the desired hardness can only be obtained by certain costly materials and / or because an additional manufacturing step is required to harden the material of the disk-shaped sealing element. Summary of the Invention [Problem to be solved by the invention]

[0006] In order to reduce these costs, experiments were carried out with an embodiment of a helical compressor in which the running sleeve's movement clearance, which causes wear of the disk-shaped sealing element, was suppressed by gluing or pressing the running sleeve into a recess. This measure allowed a reduction in material wear due to a reduction in end face friction. However, no improvement in wear characteristics was observed. Fixing the running sleeve in the recess, for example by gluing or pressing, increased the radial wear on the inner surface of the running sleeve, with a corresponding increase in material wear and disadvantage for the entire system connected to it.

[0007] Therefore, there remains a need for a helical compressor that can alleviate known drawbacks. [Means for solving the problem]

[0008] The present invention therefore aims to propose a helical compressor which can be manufactured in an inexpensive manner and which reduces material wear and allows for an extended operating life.

[0009] This object is achieved by a helical compressor having the features of claim 1. Advantageous embodiments or further developments of the helical compressor are set out in the dependent claims.

[0010] The helical compressor according to the invention comprises a fixed helical element with a fixed helical wall and a rotating helical element with a rotating helical wall arranged on a rotatable plate which joins with the fixed helical wall such that a number of compression chambers are formed. The helical compressor according to the invention further comprises guide means provided for guiding the rotating helical element. The guide means consist of at least two guide pins arranged in a fixed manner on the back surface of the rotating helical element and at least two recesses with a running sleeve inserted therein in a radially movable manner. The fixedly arranged guide pins are received in the running sleeve such that the inner surface of the running sleeve rotates around the circumference of the guide pins when the rotating helical element rotates. According to the invention, at least one lock is formed in the recess, which lock prevents the running sleeve from protruding axially from the recess.

[0011] In the sense of the present invention, the directional indication "axially" means a direction longitudinal or longitudinally parallel to the axis of rotation of the rotating helical element.

[0012] The lock formed in the recess advantageously limits the axial movement of the running sleeve so as to prevent end face friction of the running sleeve on a disc-shaped sealing element arranged between the housing body of the helical compressor and the back surface of the rotating helical element.

[0013] The guide pin can be fixedly disposed within the disc-shaped sealing element, in which case the disc-shaped sealing element is fixedly connected to the housing body, or the guide pin can be disposed in the housing body, in which case the guide pin passes through the disc-shaped sealing element and is received by the running sleeve in a recess in the rotating helical element.

[0014] According to the concept of the invention, the running sleeve is arranged in a recess of the rotating helical element so as to be substantially immobile in the axial direction via a lock. The recess and the running sleeve are preferably formed in a circular shape. The fit between the recess and the running sleeve inserted in the recess is formed as a clearance fit with a predetermined clearance, which ensures a radial mobility that allows the running sleeve to rotate about its own axis in the recess.

[0015] In order to axially lock the running sleeve inserted in the recess, a material deformation can be formed in the end region of the recess, which is selectively directed at least against the end face of the running sleeve, the material deformation which forms the lock is preferably formed so that it does not protrude beyond the inner circumference into the running sleeve, this measure being provided in order to avoid contact between the material deformation and a guide pin received in the running sleeve.

[0016] The deformation of the material is preferably formed in the edge region of the recess through deformation of the material of a rotating helical element.

[0017] According to an embodiment of the helical compressor according to the invention, the material deformations project into the respective recesses and thus form a changed shape of the cross section of the recesses. The material deformations can preferably be formed in the end regions of the respective recesses.

[0018] According to a particularly simple embodiment of the helical compressor according to the invention, the deformation of the material can be realized by stem blowing, notch blowing and / or beading or crimping for axial locking of the running sleeve inserted in the recess. For this purpose, corresponding deformation tools and deformation methods can be adopted, in which case the edges of the recess can be completely beaded so that the running sleeve inserted in the recess does not protrude axially out of the recess.

[0019] It has been shown that an adequate axial lock can already be achieved by individual selective material deformation by stem blowing in the edge region of the recess.

[0020] According to a further embodiment of the helical compressor according to the invention, the recess can alternatively or additionally have an undercut on the inner circumferential side, in which an end region of the respective inserted running sleeve is deformed by beading or crimping. The undercut is preferably realised by an annular groove formed on the inner circumferential side of the recess. The material deformation of the running sleeve is then configured so that the running sleeve inserted in the recess can rotate about its axis. As a result, the deformation of the running sleeve takes place in such a way that there is sufficient clearance between the recess and the running sleeve to allow a radial movement and rotation of the running sleeve in the recess.

[0021] The recesses are preferably formed as blind holes. In every recess a running sleeve can be placed.

[0022] According to yet another embodiment of the helical compressor, the locking can be formed by mechanical locking means which are inserted into the recess. For example, the locking can be formed by inserting the respective ring element into the recess. For this purpose, a respective annular groove into which the ring element is inserted can be formed on the inner circumferential lateral surface of the recess. The ring element can then be inserted in a form-fit manner into the annular groove formed on the inner circumferential lateral surface of the recess or by press-fitting into the recess. The annular groove formed on the inner circumferential lateral surface of the recess is arranged in an area above the edge of the recess. The ring element which is pressed into the recess can also be called a press ring. Preferably, such a press ring is formed such that its inner diameter is larger than the inner diameter of the running sleeve, and the press ring prevents an axial projection out of the recess. Preferably, the respective ring element or press ring is inserted into the recess in order to limit the axial movement of the running sleeve inserted into the recess within the meaning of the present invention.

[0023] As an advantageous further development, the recess can have an enlarged cross section in the area with the landing, which serves as a seat for the ring element. The enlarged cross section is formed on the back surface of the rotating helical element in the recess, so that a corresponding ring element forming the lock can be inserted into the recess via the back surface of the rotating helical element. The landings formed as ring element seats, which are respectively formed in the recess in this embodiment, advantageously provide a position of the ring element such that incorrect positioning of the lock can be avoided. Preferably, in this embodiment, a ring element in the form of a press ring is used, which is inserted into the recess with a press fit in order to limit the axial mobility of the running sleeve inserted in the recess, so that the running sleeve does not protrude beyond the surface of the back surface of the rotating helical element.

[0024] According to the invention, the lock of the running sleeve, which is inserted into the recess, is respectively formed in such a way that during operation of the compressor, the end face of the running sleeve does not protrude axially beyond the back face of the rotating helical element. As a result, the axial positioning of the running sleeve is advantageously selected so that the end face of the running sleeve does not come into contact with the surface of the disk-shaped sealing element. The same also applies to the lock formed with the purpose of limiting the axial movement of the running sleeve, which is respectively formed in the recess or inserted into the recess so that it does not protrude axially beyond the back face of the rotating helical element.

[0025] The running sleeve is therefore preferably arranged in the recess so that its end face does not protrude above the plane of the rear surface of the rotating helical element, preferably below said plane.

[0026] The running sleeve and guide pin may be formed from a material having a greater hardness than the material from which the rotating helical element is formed. Preferably, the guide pin and running sleeve are formed from the same material.

[0027] The rotating helical element may advantageously be formed from a cheaper and / or relatively light material, such as aluminum.

[0028] According to an advantageous embodiment of the helical compressor according to the invention, it can be provided that the running sleeve and the guide pin are made of hard metal and that the rotating helical element is made of aluminum. It can further be provided that the rotating helical element is made of cast iron or steel. Effect of the Invention

[0029] According to the invention, there is an advantage that the running sleeve, which is axially locked in the recess formed in the side of the rear wall, does not come into contact with the disk-shaped sealing element, so that wear of the disk-shaped sealing element through the running sleeve is avoided. The material of the disk-shaped sealing element can therefore be formed with or have a lower hardness than the material of the running sleeve. This has a great cost advantage, since the manufacturing step of hardening the disk-shaped sealing element is omitted. Thus, the choice of material for forming the disk-shaped sealing element is broadened. Lighter materials can therefore also be advantageously used. Due to the reduced wear of the material, the helical compressor according to the invention has an increased operating life. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is a schematic exploded view of a helical compressor as known in the art. [Diagram 2] FIG. 2 is a schematic diagram of an exemplary embodiment of a rear view of a rotating helical element of a helical compressor according to the present invention. [Figure 3a] FIG. 2 is a close-up schematic diagram of an exemplary embodiment of a recess in the rear of a rotating helical element of a helical compressor according to the present invention. [Figure 3b] FIG. 2 is a close-up schematic diagram of an exemplary embodiment of a recess in the rear of a rotating helical element of a helical compressor according to the present invention. [Figure 3c] FIG. 2 is a close-up schematic diagram of an exemplary embodiment of a recess in the rear of a rotating helical element of a helical compressor according to the present invention. [Figure 4a] FIG. 2 is an enlarged schematic view of a second embodiment of a recess in the rear surface of a rotating helical element of a helical compressor according to the present invention; [Figure 4b] FIG. 2 is an enlarged schematic view of a second embodiment of a recess in the rear surface of a rotating helical element of a helical compressor according to the present invention; [Figure 5a] 4A and 4B are an enlarged schematic cross-sectional view and a detailed view of a third embodiment of a recess in the rear surface of a rotating helical element of a helical compressor according to the present invention; [Figure 5b]4A and 4B are an enlarged schematic cross-sectional view and a detailed view of a third embodiment of a recess in the rear surface of a rotating helical element of a helical compressor according to the present invention; [Figure 6a] 4A and 4B are an enlarged schematic view and a detailed cross-sectional view of a fourth embodiment of a recess in the rear surface of a rotating helical element of a helical compressor according to the present invention; [Figure 6b] 4A and 4B are an enlarged schematic view and a detailed cross-sectional view of a fourth embodiment of a recess in the rear surface of a rotating helical element of a helical compressor according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Further details, features and advantages of embodiments of the invention emerge from the following description of exemplary embodiments with reference to the attached drawings. FIG. 1 is a schematic exploded view of a helical compressor known in the art. The helical compressor has a fixed helical element 1 with a fixed helical wall formed thereon. In the perspective view of FIG. 1, the fixed helical wall formed on the fixed helical element 1 is covered by the circumference of the fixed helical element 1. A rotating helical element 2 having a rotating helical wall 3 arranged on a rotatable plate is arranged opposite the fixed helical element 1. In the assembled state, the rotating helical wall 3 interlocks with the fixed helical wall of the fixed helical element 1 such that a number of compression working chambers are formed between the interlocking helical walls.

[0032] For guiding the rotating helical element 2, guide means are provided with six fixed guide pins 4 which are received in six recesses 11 formed in the back surface of the rotating helical element 2, which is covered in a perspective view of the rotating helical element 2. The guide pins 4 are fixedly arranged in evenly arranged openings 5 ​​of a disk-shaped sealing element 6. The disk-shaped sealing element 6 is arranged between the housing body 7 and the rotating helical element 2 and has a radial circumferential notch 8 for receiving an O-ring 9 for sealing the disk-shaped sealing element 6 to the housing body 7. Preferably, the disk-shaped sealing element 6 is not hardened and / or is made of the same material as the housing body 7. The housing body 7 and the disk-shaped sealing element 6 have corresponding openings into which pins 10 are inserted for fixedly connecting the disk-shaped sealing element 6 to the housing body 7.

[0033] According to this technique, a respective radially and axially movable running sleeve 12 is inserted into each of the six recesses 11. In the assembled state of the helical compressor, the axial and radial clearances of the running sleeve 12 allow radial and axial movement of the running sleeve 12 inserted in the recesses 11.

[0034] The guide pin 4 is axially arranged opposite the recess 11 such that in the assembled state of the helical compressor the guide pin 4 is received in the running sleeve 12 so that the inner surface of the running sleeve 12 rotates about the circumference of the guide pin 4 when the rotating helical element 2 rotates.

[0035] A ring seal 13 with an O-ring 14 is arranged between the rotating spiral element 2 and the disk-shaped sealing element 6 .

[0036] In contrast to the embodiment of the helical compressor according to the state of the art shown in FIG. 1, the axial mobility of the running sleeve 12 in the helical compressor according to the invention is limited by a respective lock formed in the recess 11 such that it cannot protrude axially out of the recess 11.

[0037] 2 shows a schematic example of an embodiment of the back surface of the rotating helical element of a helical compressor according to the invention. The back surface of the rotating helical element 2 facing the disk-shaped sealing element 6 (not shown) is formed with six circular recesses 11 evenly distributed. A running sleeve 12 is inserted into each recess 11, and the inner diameter of the recess 11 is larger than the outer diameter of the running sleeve 12, so that the running sleeve 12 inserted into the recess 11 has a clearance to move radially. The clearance between the running sleeve 12 and the recess 11 allows the running sleeve 12 to rotate.

[0038] The material of the running sleeve 12 is harder than the material of which the rotating helical element 2 is made. Preferably, the running sleeve 12 and the guide pin 4 are made from steel, particularly preferably from hardened steel.

[0039] In the end region of the recess 11, two material deformations 15 selectively directed against the end face of the running sleeve 12 are formed as locks limiting the axial movement of the running sleeve 12 in the recess 11, so that the running sleeve 12 cannot protrude beyond the back face of the rotating helical element 2 from the recess 11. The material deformations 15 are selectively stemmed, so that the material of the rotating helical element 2, for example aluminum, is deformed from the edge of the recess 11 into the inside of the respective recess 11, so that the axial movement of the running sleeve 12 inserted in the respective recess 11 is limited. The selective material deformations 15 are formed so that they do not protrude beyond the end face of the running sleeve 12 into the running sleeve 12. In the illustrated example, the selective material deformations 15 each protrude 0.25 mm into the recess 11, thus blocking the running sleeve 12 against axial protrusion from the recess 11. The width of the selective deformations 15 is 0.25 mm. The depth of the selective material deformations 15 is 0.2 mm, measured from the upper edge of the recess 11.

[0040] 3a-3c are enlarged schematic views of an exemplary embodiment of a recess 11 in the rear of the rotating helical element 2 of a helical compressor according to the present invention.

[0041] FIG. 3a shows an embodiment in which a running sleeve 12 inserted in a recess 11 is locked against the axial projection with individual material deformations 15 at the edge of the recess 11 selectively formed by the stem stroke.

[0042] Figure 3b is a detailed representation of a further embodiment of the solution according to the invention, in which the axial locking of the running sleeve 12 inserted into the recess 11 of the rotating helix element 2 is formed by three material deformations 15 selectively distributed and uniformly formed around the circumference of the edge of the recess 11.

[0043] Fig. 3c is a further detailed representation of the axial lock formed by a material deformation 15 in the end face region of the recess 11 of the running sleeve 12 inserted in the recess 11. The material deformation 15 is formed in such a way that it is directed against the end face of the running sleeve 12 without clamping the latter. This allows the running sleeve 12 in the recess 11 to rotate about its own axis. The material deformation 15 prevents the running sleeve 12 from protruding axially out of the recess beyond the back face of the rotating spiral element 2.

[0044] 4a and 4b are enlarged schematic views of a second embodiment of a recess 11 at the back of the rotating helical element 2 of a helical compressor according to the invention. In FIG. 4a an embodiment of the recess 11 is shown, in which the axial lock of the running sleeve 12 inserted in the recess 11 is formed by a material deformation 15 at the edge of the recess 11. The material deformation 15 is obtained by beading the material of the rotating helical element 2 at the edge of the recess 11 to the inside in the direction of the end face of the running sleeve 12. The beaded edge of the recess 11 protrudes into the recess 11 and thus reduces the cross section of the recess 11. Due to the reduced cross section, the running sleeve 12 inserted in the recess 11 is axially locked and cannot protrude out of the recess 11 beyond the back of the rotating helical element 2.

[0045] FIG. 4b shows an enlarged cross-sectional view of the recess 11 of FIG. 4a with a bead edge for axially locking the running sleeve 12 inserted in the recess 11. The material deformation 15, i.e. the bead edge, projects inwardly relative to the end face of the running sleeve 12 without axially clamping the latter. The material deformation 15 does not project beyond the end face into the running sleeve 12. The diameter of the recess 11 in the region of the bead edge is smaller than the outer diameter of the running sleeve 12 and larger than the inner diameter of the running sleeve 12.

[0046] 5a and 5b show enlarged schematic cross-sectional views of a third embodiment of a recess 11 in the rear of a rotating helical element 2 of a helical compressor according to the invention, with FIG. 5b showing a detailed view of FIG. 5a.

[0047] FIG. 5a shows a cross section of the recess 11 with the running sleeve 12 inserted therein. In this third embodiment, the recess 11 has an annular groove 16 formed on its inner circumferential side surface, and the running sleeve 12 in the region of the annular groove 16 is deformed in such a way that the material of the running sleeve 12 protrudes into the annular groove 16, whereby the running sleeve 12 is axially locked in the recess 11. The deformation of the material of the running sleeve 12 in the region of the annular groove 16 can be formed by beading or crimping. The annular groove 16 formed on the lower edge of the recess 11 serves as an undercut, through which the deformed end region of the running sleeve 12 protrudes, without radially clamping the running sleeve 12 in the recess 11. The deformation of the edge region of the running sleeve 12 is therefore selected in such a way that radial clearance of the running sleeve 12 in the recess 11 is guaranteed.

[0048] FIG. 5b is an enlarged cross-sectional view of an embodiment of a recess 11 with a ring groove 16 as shown in FIG. 5a, into which a deformed material portion 15 of the running sleeve 12 protrudes to axially lock the running sleeve 12 within the recess 11.

[0049] Figures 6a and 6b show an enlarged schematic view of a fourth embodiment of a recess 11 in the rear of a rotating helical element 2 of a helical compressor according to the invention, and Figure 6b shows a detailed view of Figure 6a.

[0050] 6a shows a recess 11 with a running sleeve 12 inserted therein and axially locked with a press ring 17 inserted in the recess 11. The press ring 17 is press-fitted into the recess 11, thereby preventing the running sleeve 12 from protruding axially out of the recess 11. The inner diameter of the press ring 17 is larger than the inner diameter of the running sleeve 12, such that contact between the inner circumferential surface of the press ring 17 and the outer circumferential surface of the guide pin 4 received in the running sleeve 12 is avoided during operation.

[0051] Figure 6b shows an enlarged cross-sectional view of an embodiment of the recess 11 depicted in figure 6a with a press ring 17 for axially locking the running sleeve 12 inserted in the recess 11. The press ring 17 is inserted in the recess 11 such that it is located slightly below the rear surface of the rotating helix element 2 in order to prevent end face friction with axially adjacent components, in particular with the disk-shaped sealing element 6. The recess 11 has an area of ​​enlarged cross section on the rear surface of the rotating helix element and is provided with a landing 18 which serves as a press ring seat for the inserted press ring 17. [Explanation of symbols]

[0052] 1 fixed helical element 2 Rotating Helix Elements 3 Rotating Spiral Wall 4 Guide pins 5 Opening 6 Disc-shaped sealing element 7 Housing body 8 notches 9 O-ring 10-pin 11 Recess 12 Running Sleeves 13. Sealing 14 O-ring 15 Material transformation material section 16 Annular groove / undercut 17 Press Ring / Ring Element 18 Landing / Press Ring Seal

Claims

1. A fixed helical element (1) having a fixed helical wall; a rotating helical element (2) disposed on a rotatable plate and having a rotating helical wall that couples with the fixed helical wall such that a plurality of compression chambers are formed; Guide means provided for guiding the rotating helical element (2); The guide means comprises at least two guide pins (4) arranged in a fixed manner; At least two recesses (11) formed on the rear surface of the rotating helical element (2) for inserting a radially movable running sleeve (12) therein. the guide pin (4) arranged in a fixed manner is received in the running sleeve (12) in such a way that the inner surface of the running sleeve (12) rotates around the circumference of the guide pin (4) when the rotating helical element (2) rotates, and at least one lock is formed in the recess (11), which prevents the running sleeve (12) from protruding axially out of the recess (11), a material deformation portion (15) protruding radially inwardly toward an end face of the running sleeve (12) is formed in an edge region of the recess (11) for axial locking of the running sleeve (12) inserted into the recess (11), the material deformation portion (15) having a flat surface formed parallel to the end face of the running sleeve (12).

2. A spiral compressor as described in claim 1, characterized in that the material deformation portion (15) in the end region of the recess (11) for axial locking of the running sleeve (12) inserted into the recess (11) is formed by a stem stroke, a notch stroke, and / or beading or crimping.

3. A spiral compressor as described in claim 1, characterized in that the running sleeve (12) is positioned within the recess (11) so that its end face does not protrude above the plane of the back surface of the rotating spiral element (2) and is located below the plane.

4. A spiral compressor as described in claim 1, characterized in that the running sleeve (12) and the guide pin (4) are formed from a material having a greater hardness than the material from which the rotating spiral element (2) is formed.

5. A spiral compressor as described in claim 4, characterized in that the running sleeve (12) and the guide pin (4) are formed from hard metal and the rotating spiral element (2) is formed from aluminum.

6. 5. A helical compressor according to claim 4, characterized in that the material of the disk-shaped sealing element (6) has a lower hardness than the material of the running sleeve (12).

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