Volumetric machine according to spiral principle

Abstract

The invention relates to a positive displacement machine, in particular a scroll compressor, according to the spiral principle, comprising a housing (100) comprising a compressor housing (20) and a drive housing (10), in which an orbiting positive displacement spiral (21) and a counter-spiral (25) are arranged in the compressor housing (20), the positive displacement spiral (21) and the counter-spiral (25) being engaged with each other, and the drive housing (10) being arranged in the compressor housing (20), and the positive displacement spiral (21) and the counter-spiral (25) being arranged in the drive housing (10). The positive displacement screw (21) and the counter-screw (25) are arranged in the drive housing (10) such that a variable compression chamber (23) is formed between the positive displacement screw (21) and the counter-screw (25) in order to receive and compress a working medium flowing through the working medium circuit, the drive shaft (12) being arranged in the drive housing (10), the drive shaft (12) being in drive connection with the positive displacement screw (21), and the bearing plate (30) being arranged between the drive housing (10) and the compressor housing (20), the bearing plate (30) carries a bearing (32) of the drive shaft (12), and wherein the anti-rotation mechanism is arranged between the bearing plate (30) and the orbiting positive displacement screw (21). The support plate (30) is arranged entirely within the housing (100), the support plate (30) and the bearing (32) being made of materials having a coefficient of thermal expansion that differs from one another by at most 20%, in particular by at most 10%, in particular by at most 5%.

Description

[0001] The invention relates to a positive displacement machine according to the screw principle having the features of the preamble of claim 1. Such a positive displacement machine is known, for example, from DE 10 2016 118 525 B4.

[0002] The above-mentioned DE 10 2016 118 525 B4 describes a positive displacement machine according to the screw principle, in particular a scroll compressor, which comprises a housing made of aluminum for corrosion protection reasons. The housing forms a wall that separates the drive chamber of the scroll compressor from the compression chamber. The wall carries a drive bearing that supports the drive shaft. The drive shaft is eccentrically engaged in an orbiting positive displacement spiral (orbitierende Verdrängerspirale), which in turn is spirally engaged with a counter-spiral. By the orbiting movement of the positive displacement spiral, which is activated by the eccentric connection to the drive shaft, a variable compression chamber is formed between the positive displacement spiral and the counter-spiral, through which the working medium can be compressed.

[0003] In known scroll compressors, an anti-rotation mechanism is also provided. The anti-rotation mechanism comprises a pin which engages in an opening at the bottom of the positive displacement spiral, thereby preventing the positive displacement spiral from rotating. In this way, the positive displacement spiral is forced into the desired orbital motion.

[0004] DE 10 2016 118 525 B4 has recognized that it is advantageous if the pin of the anti-rotation mechanism is not inserted directly into the aluminum wall, but rather a steel sliding plate is constructed between the aluminum wall and the positive displacement screw. The pin of the anti-rotation mechanism is inserted into this sliding plate and engages in the opening of the positive displacement screw. For reasons of durability, the pin is also made of steel.

[0005] The wall that carries the sliding plate is at the same time the support plate that carries the bearing of the drive shaft.In order to ensure good durability, the drive shaft bearing is usually made of steel.

[0006] Due to the different materials between the bearing plate and the bearing, different thermal expansions occur during operation of the positive displacement machine. This must be taken into account when pressing the bearing into the bearing plate and can result in very small bearing clearances during partial load operation of the positive displacement machine or in pretensioning of the bearing during operation. Both have a negative impact on the service life of the bearing.

[0007] The object of the present invention is to provide a positive displacement machine according to the screw principle which has a longer service life. In particular, the bearings of the drive shaft should have a longer service life due to the present invention.

[0008] According to the invention, this object is achieved by the subject matter of claim 1 .

[0009] Specifically, the present invention is based on the following idea: to provide a volumetric machine according to the screw principle, in particular a scroll compressor, the volumetric machine comprising a housing, the housing comprising a compressor housing and a drive housing. An orbiting volumetric spiral and an anti-spiral are arranged in the compressor housing, the volumetric spiral machine and the anti-spiral are engaged with each other, so that a variable compression chamber is formed between the volumetric spiral and the anti-spiral to accommodate and compress the working medium flowing through the working medium circuit. A drive shaft is arranged in the drive housing, the drive shaft is connected to the volumetric spiral by driving, wherein a support plate of a bearing carrying the drive shaft is arranged between the drive housing and the compressor housing. An anti-rotation mechanism is provided between the support plate and the orbiting volumetric spiral. According to the present invention, the support plate is completely arranged in the housing, wherein the support plate and the bearing are made of materials whose thermal expansion coefficients differ from each other by at most 20%, in particular at most 10%, in particular at most 5%.

[0010] The invention makes use of two main effects. On the one hand, the material selection of the support plate and the bearing ensures that the bearing is not strained against the support plate during operation, thereby extending the service life of the bearing. On the other hand, the support plate is completely arranged in the housing. This results in the possibility of selecting a different material for the support plate than for the housing. For example, the housing can be made of aluminum and provide suitable corrosion protection. The support plate can, on the other hand, be made of steel and have sufficient strength to fix the bearing. In this regard, the invention is also based on the idea of ​​functional separation between the housing and the support plate. While in the prior art the housing and the support plate are usually formed in one piece, the invention uses a two-piece design so that each component can be optimally configured for the function assigned to it.

[0011] By producing the bearing plate and the bearing from materials having similar coefficients of thermal expansion, the press fit between the bearing plate and the bearing can therefore be dimensioned very well, which has a positive effect on the service life of the bearing.

[0012] The support plate can be connected to the housing in a force-fitting manner. In particular, the support plate can be connected to the housing by a press fit, a screw connection, a riveting connection or a pin connection.

[0013] In one embodiment, it is particularly provided that the bearing plate is fastened in a housing ring which is arranged between the drive housing and the compressor housing. This variant emphasizes good maintenance friendliness. The housing itself has a drive housing, a housing ring and a compressor housing. Preferably, the housing ring is connected to the bearing plate in a force-fitting manner. Preferably, the material of the housing ring corresponds to the material of the drive housing and the compressor housing. Preferably, the bearing plate is made of another material, in particular steel.

[0014] In particular, in a preferred embodiment it is provided that the housing ring has a different material than the bearing plate and / or the compressor housing. Preferably, the material of the housing ring is corrosion-resistant, in particular aluminum.

[0015] Alternatively, it can be provided that the support plate is fastened in the drive housing. In this variant, a separate housing ring is omitted. Here, the variety of components is reduced, which has a positive effect on manufacturing costs.

[0016] In a further preferred embodiment it is provided that the support plate is fastened in the compressor housing.

[0017] Another alternative variant of the invention provides that the support plate is firmly connected to the counter-helix element, in particular in a force-fitting manner. The above-mentioned force-fitting connection can be used for all variants.

[0018] In another preferred embodiment of the invention, the orbiting positive displacement screw has a positive displacement screw bottom in which a sealing element is fastened. The sealing element seals the orbiting positive displacement screw from the support plate and thus from the drive housing. This increases the efficiency of the positive displacement machine.

[0019] Furthermore, the sliding plate can be arranged between the support plate and the orbiting positive displacement screw (in particular the positive displacement screw bottom). Preferably, the sliding plate is completely arranged in the housing. Particularly preferably, the sealing element seals the sliding plate.

[0020] Preferably, the sliding plate is made of a material with good sliding and sealing properties. This reduces friction within the volumetric machine and increases the efficiency of the volumetric machine. At the same time, vibration and noise emissions are reduced, which is very important for applications in the field of electric vehicles.

[0021] The following will be described based on the embodiments and with reference to the attached drawings. picture The present invention will be described in more detail. picture A partial cross-sectional view of a volumetric machine according to the invention is shown according to a preferred embodiment picture .

[0022] FIG. 1 specifically shows a part of a positive displacement machine, in particular a scroll compressor, which comprises a housing 100. The housing 100 is divided into a drive housing 10 and a compressor housing 20. In the embodiment shown here, a housing ring 31 is arranged between the drive housing 10 and the compressor housing 20. The housing ring 31 is firmly connected to the drive housing 10 and the compressor housing 20. Preferably, the drive housing 10, the compressor housing 20 and the housing ring 31 are made of an aluminum alloy.

[0023] Furthermore, a drive shaft 12 is arranged in the drive housing 10. The drive housing 10 may also include an electric motor (not shown here) which drives the drive shaft 12 directly.

[0024] The drive shaft 12 penetrates the support plate 30 and is supported in the support plate 30 in a bearing 32. Preferably, the bearing 32 is fixed in the support plate 30 by a press fit. Upstream of the bearing 32 is a shaft seal 11 which surrounds the drive shaft 12, thereby tightly sealing the drive housing 10 relative to the support plate 30.

[0025] The drive shaft 12 engages in an eccentric bearing 14 via a compensation mechanism 13. The eccentric bearing 14 engages with an orbiting positive displacement screw 21, so that drive energy can be transmitted to the orbiting positive displacement screw 21 via the drive shaft 12 and the eccentric bearing 14.

[0026] In accordance with the attached picture In the positive displacement machine of the invention, an anti-rotation mechanism 40 is also provided. The anti-rotation mechanism 40 comprises a pin 41 which is firmly fastened in the support plate 30. The pin 41 engages with clearance in a ring 42 which is arranged in the opening of the positive displacement screw 21. By means of the clearance between the ring 42 and the pin 41, it is achieved that the positive displacement screw 21 is forced to perform an orbital movement by means of the eccentricity on the drive shaft 12. Thus, the positive displacement screw is prevented from simply rotating.

[0027] In order to ensure a good seal between the orbiting volumetric screw 21 and the support plate 30, the support plate 30 also carries a sliding plate 33. The orbiting volumetric screw 21 also includes a sealing element 24, which is pressed against the sliding plate 33 to form a good seal. The sealing element 24 can be a surrounding O-ring.

[0028] From the attached picture It can also be clearly seen that the support plate 30 is completely arranged in the housing. The support plate 30 is firmly connected to the counter-spiral member 25. In particular, the connection can be carried out in a force-fitting manner. For example, the support plate 30 can be fixed to the counter-spiral member 25 by a fastening pin inserted in a press-fitting manner. Alternatively, a screw connection, a riveting or a tolerance ring design can also be adopted.

[0029] The bearing plate 30 can be made of steel or a cast material. Preferably, the material used to manufacture the bearing 32 is used. In any case, the bearing plate 30 and the bearing 32 should be made of materials with the same or at least similar coefficients of thermal expansion. During operation of the volumetric machine, the bearing 32 and the bearing plate 30 expand uniformly. As a result, the press fit between the bearing 32 and the bearing plate 30 can be well and precisely dimensioned, which has a positive effect on the service life of the bearing 32.

[0030] Reference Mark List 10 Drive housing 11 Shaft seal 12 Drive shaft 13 Compensation Agency 14 Eccentric bearing 20 Compressor housing 21 Orbiting positive displacement spiral 22 Volumetric screw bottom 23 Compression chamber 24 Sealing element 25 Anti-Spiral 30 Support plate 31 Shell ring 32 Bearings 33 Sliding Plate 40 Anti-rotation mechanism 41 Pins 42 rings 100 Shell.

Claims

1. A positive displacement machine according to the screw principle, in particular a scroll compressor, comprising a housing (100), the housing (100) comprising a compressor housing (20) and a drive housing (10), wherein: An orbiting positive displacement spiral (21) and an anti-spiral spiral (25) are arranged in the compressor housing (20), the positive displacement spiral (21) and the anti-spiral spiral (25) are engaged with each other, so that a variable compression chamber (23) is formed between the positive displacement spiral (21) and the anti-spiral spiral (25) to accommodate and compress the working medium flowing through the working medium circuit, wherein a drive shaft (12) is arranged in the drive housing (10), the drive shaft (12) is drivingly connected to the positive displacement spiral (21), wherein a support plate (30) is arranged between the drive housing (10) and the compressor housing (20), the support plate (30) carries a bearing (32) of the drive shaft (12), and wherein an anti-rotation mechanism (40) is provided between the support plate (30) and the orbiting positive displacement spiral (21), It is characterized in that The support plate (30) is arranged completely within the housing (100), wherein the support plate (30) and the bearing (31) are made of materials whose coefficients of thermal expansion differ from each other by at most 20%, in particular at most 10%, in particular at most 5%.

2. The volumetric machine according to claim 1, characterized in that The support plate (30) is connected to the housing (100) in a force-fitting manner.

3. A volumetric machine according to claim 1 or 2, characterized in that The bearing plate (30) is fastened in a housing ring (31) which is arranged between the drive housing (10) and the compressor housing (20).

4. The positive displacement machine according to claim 3, characterized in that The housing ring (31) comprises a different material than the bearing plate (30), in particular the same material as the drive housing (10) and / or the compressor housing (20).

5. The volumetric machine according to claim 1 or 2, characterized in that: The support plate (30) is fastened in the drive housing (10).

6. A positive displacement machine according to claim 1 or 2, characterized in that The support plate (30) is fastened in the compressor housing (20).

7. A volumetric machine according to any one of the preceding claims, characterised in that The support plate (30) is firmly connected to the counter-spiral element (25), in particular, firmly connected in a force-fitting manner.

8. A volumetric machine according to any one of the preceding claims, characterised in that The orbiting positive displacement spiral (21) has a positive displacement spiral bottom (22) in which a sealing element (24) is fastened.

9. A volumetric machine according to any one of the preceding claims, characterised in that The sliding plate (33) is arranged between the support plate (30) and the orbiting positive displacement screw (21), in particular, between the support plate (30) and the positive displacement screw bottom (22).

10. The positive displacement machine according to claim 9, characterized in that The sliding plate (33) is completely arranged within the housing (100).

11. A positive displacement machine according to claim 9 or 10, characterised in that The sealing element (24) seals the sliding plate (40).

Images