Volumetric machines based on the spiral principle

Abstract

A positive displacement machine based on the spiral principle, specifically a scroll compressor, with a housing (100) including a compressor housing (20) and a drive housing (10), in which an orbital displacement spiral (21) and an opposing spiral (25) are arranged, and a variable compression chamber (23) is formed between the orbital displacement spiral (21) and the opposing spiral (25) for receiving and compressing the working medium flowing through the working medium circuit. A positive displacement machine based on the spiral principle, in particular a scroll compressor, in which the drive shaft (12) is arranged in the drive housing (10), the drive shaft is drivingly connected to the displacement spiral (21), a bearing plate (30) is arranged between the drive housing (10) and the compressor housing (20), the bearing plate carries bearings (32) for the drive shaft (12), and an anti-rotation mechanism is provided between the bearing plate (30) and the orbital displacement spiral (21). The bearing plate (30) is completely arranged inside the housing (100), and the bearing plate (30) and the bearing (32) are made of materials having thermal expansion coefficients that differ from each other by at most 20%, in particular at most 10%, in particular at most 5%.

Description

[Technical field]

[0001] The invention relates to a positive displacement machine based on the spiral 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. [Background technology]

[0002] DE 10 2016 118 525 B4, mentioned at the outset, describes a positive displacement machine based on the spiral principle, with a housing made of aluminum for corrosion protection reasons. The housing forms a wall, which separates the drive space of the scroll compressor from the compression space. The wall carries a drive bearing, which supports a drive shaft. The drive shaft is eccentrically engaged into an orbital displacement spiral. The orbital displacement spiral is in spiral engagement with a counter spiral. The orbital movement of the displacement spiral, which is introduced by the eccentric coupling with the drive shaft, results in a variable compression chamber between the displacement spiral and the counter spiral. The working medium can be compressed via this compression chamber.

[0003] Known spiral compressors further include an anti-rotation mechanism, which includes a pin that engages in an opening at the bottom of the displacement spiral and thus prevents the displacement spiral from rotating, forcing the displacement spiral into a desired orbital motion.

[0004] In DE 10 2016 118 525 B4 it has proven advantageous if the pin of the anti-rotation mechanism is not inserted directly into the aluminum wall, but rather a slide plate made of steel is formed between the aluminum wall and the displacement spiral. The pin of the anti-rotation mechanism is inserted into this slide plate and engages in an opening in the displacement spiral. For reasons of a long service life, the pin is also made of steel. Summary of the Invention [Problem to be solved by the invention]

[0005] The wall carrying the slide plate is at the same time a bearing plate, which carries the bearing for the drive shaft. To ensure good durability, the drive shaft bearing is usually made of steel.

[0006] The different materials of the bearing plate and the bearings result in different thermal expansions during operation of the displacement machine, which must be taken into account when pressing the bearings into the bearing plate, and the bearing play can become too small during partial load operation of the displacement machine or the bearings can become preloaded during operation, both of which have a negative effect on the service life of the bearings.

[0007] The object of the present invention is to provide a positive displacement machine based on the spiral principle which has an improved service life, in particular the bearings of the drive shaft which are provided with an increased service life according to the present invention. [Means for solving the problem]

[0008] This problem is solved according to the invention by the subject matter of claim 1.

[0009] In particular, the invention is based on the idea of ​​providing a positive displacement machine based on the spiral principle, in particular a scroll compressor, with a housing including a compressor housing and a drive housing. In the compressor housing, a displacer spiral and a counter spiral are arranged, which engage with each other in and outwardly such that a variable compression chamber is formed between the displacer spiral and the counter spiral for receiving and compressing the working medium flowing through the working medium circuit. In the drive housing, a drive shaft is arranged, which is drivingly connected with the displacer spiral, and between the drive housing and the compressor housing, a bearing plate is arranged, which bears a bearing for the drive shaft. Between the bearing plate and the displacer spiral, an anti-rotation mechanism is provided. According to the invention, the bearing plate is arranged completely inside the housing, and the bearing plate and the bearing are made of materials having thermal expansion coefficients that differ from each other by at most 20%, in particular by at most 10%, in particular by at most 5%.

[0010] The invention essentially utilizes two advantages. On the one hand, the material selection for the bearing plate and the bearing means that the bearing is not tensioned by the bearing plate during operation, which increases the service life of the bearing. On the other hand, the bearing plate is completely arranged inside the housing. This leads to the selection of a different material for the bearing plate than for the housing; the housing is made of aluminum, for example, and provides corresponding corrosion protection. The bearing plate, on the other hand, is made of steel, which is strong enough to hold the bearing. In this respect, the invention is also based on the idea of ​​a functional separation of the housing and the bearing plate. Whereas in the prior art the housing and the bearing plate are often made in one piece, the invention utilizes a two-part construction, so that each part can be made optimally for the function assigned to it.

[0011] That is, the bearing plate and the bearing are made of materials having similar coefficients of thermal expansion, so that the press fit between the bearing plate and the bearing can be well dimensioned, which has a favorable effect on the service life of the bearing.

[0012] The bearing plate may be frictionally connected to the housing, in particular by press fitting, screwing or by riveting or pinning.

[0013] In one embodiment, the bearing plate is fixed in a housing ring, which is arranged between the drive housing and the compressor housing. In this variant, good maintenance is possible. The housing itself comprises a drive housing, a housing ring and a compressor housing. The housing ring is preferably frictionally connected to the bearing plate. The material of the housing ring preferably corresponds to the material of the drive housing and the compressor housing. The bearing plate is preferably made of another material, in particular steel.

[0014] In particular, in the case of a preferred embodiment, the housing ring has a different material than the bearing plate and / or the compressor housing, the material of the housing ring being preferably corrosion-resistant, in particular aluminum.

[0015] Alternatively, the bearing plate can be fixed in the drive housing. In the case of such a variant, a separate housing ring is not required. Various components are reduced, which has a favorable effect on the manufacturing costs.

[0016] In a further advantageous embodiment, the bearing plate is fixed in the compressor housing.

[0017] In yet another variant of the invention, the bearing plate is rigidly connected to the counter spiral, in particular frictionally connected, the aforementioned frictional connection being usable for all variants.

[0018] In a further advantageous embodiment of the invention, the orbital displacement spiral has a displacement spiral bottom, in which a sealing element is fixed, which provides a sealing effect of the orbital displacement spiral against the bearing plate and thus against the drive housing, which increases the efficiency of the positive displacement machine.

[0019] A sliding plate may further be arranged between the bearing plate and the orbital displacement spiral, in particular the bottom of the displacement spiral. Advantageously, the sliding plate is arranged completely inside the housing. It is particularly advantageous if the sealing element is sealed against the sliding plate.

[0020] The slide plate is advantageously made of a material with good sliding and sealing properties, which reduces friction inside the displacement machine and increases its efficiency, while at the same time reducing vibrations and noise emissions, which is important for use in the field of electric mobility.

[0021] The invention will now be described in more detail by way of an embodiment with reference to the accompanying drawings, in which: FIG. [Brief description of the drawings]

[0022] [Figure 1] The only figure shows a partial cross-sectional view of a positive displacement machine according to the present invention in accordance with an advantageous embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] 1 shows in particular a section of a positive displacement machine, in particular a scroll compressor, with 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 fixedly connected to the drive housing 10 and to the compressor housing 20. Advantageously, the drive housing 10, the compressor housing 20 and the housing ring 31 are made of an aluminum alloy.

[0024] A drive shaft 12 is further arranged in the drive housing 10. The drive housing 10 can further comprise an electric motor, not shown here, which drives the drive shaft 12 directly.

[0025] The drive shaft 12 passes through the bearing plate 30 and is supported within the bearing plate 30 on a bearing 32. The bearing 32 is fixed in the bearing plate 30, preferably by a press fit. The bearing 32 is preceded by a shaft seal 11. The shaft seal surrounds the drive shaft 12 and thus closes the drive housing 10 tightly against the bearing plate 30.

[0026] The drive shaft 12 is engaged in an eccentric bearing 14 via a compensation mechanism 13. The eccentric bearing 14 is engaged with a track displacement spiral 21, so that the drive energy can be transmitted to the track displacement spiral 21 via the drive shaft 12 and the eccentric bearing 14.

[0027] In the case of the illustrated positive displacement machine, an anti-rotation mechanism 40 is further provided. The anti-rotation mechanism 40 comprises a pin 41, which is immovably fixed in the bearing plate 30. The pin 41 engages with play in a ring 42, which is arranged in the opening of the displacement spiral 21. Through the play between the ring 42 and the pin 41, the displacement spiral 21 is forced into an orbital movement by the eccentricity of the drive shaft 12. Simple rotation of the displacement spiral is thus prevented.

[0028] To ensure a good seal between the orbit-displacement spiral 21 and the bearing plate 30, the bearing plate 30 further carries a slide plate 33. The orbit-displacement spiral 21 further comprises a sealing element 24. The sealing element is pressed against the slide plate 33 and thus provides a good seal. The sealing element 24 may be an annular O-ring.

[0029] As can be clearly seen, the bearing plate 30 is completely arranged inside the housing. The bearing plate 30 is fixedly connected to the counter spiral 25. The connection can in particular be effected by a forced fit. For example, a fastening pin inserted by press fitting can hold the bearing plate 30 on the counter spiral 25. Alternatively, a screw fastening, a riveting or a tolerance ring arrangement are also possible.

[0030] The bearing plate 30 may be made of steel or cast material. Advantageously, the material is used which is also used for the manufacture of the bearing 32. In any case, the bearing plate 30 and the bearing 32 should be made of materials having the same or at least similar coefficients of thermal expansion. During operation of the displacement machine, the bearing 32 and the bearing plate 30 expand uniformly. The press fit between the bearing 32 and the bearing plate 30 can thus be well and accurately dimensioned. This has a favorable effect on the service life of the bearing 32. [Explanation of symbols]

[0031] 10 Drive unit housing 11 Shaft seal 12 Drive shaft 13 Compensation mechanism 14 Eccentric bearing 20 Compressor housing 21 Track Displacement Spiral 22 Displacement spiral bottom 23 Compression chamber 24 Sealing element 25 Opposing Spiral 30 Bearing plate 31 Housing Ring 32 Bearings 33 Slide plate 40 Anti-rotation mechanism 41 pin 42 Ring 100 Housing

Claims

1. A positive displacement machine based on the spiral principle, in particular a scroll compressor, with a housing (100) including a compressor housing (20) and a drive housing (10), in which an orbital displacement spiral (21) and an opposing spiral (25) are arranged, the orbital displacement spiral (21) and the opposing spiral (25) being provided with a variable compression chamber (23) between the displacement spiral (21) and the opposing spiral (25) for receiving and compressing the working medium flowing in the working medium circuit. a drive shaft (12) is arranged in the drive housing (10) and is drivingly connected to the displacement spiral (21); a bearing plate (30) is arranged between the drive housing (10) and the compressor housing (20), the bearing plate (30) carrying a bearing (32) for the drive shaft (12), and an anti-rotation mechanism (40) is provided between the bearing plate (30) and the orbital displacement spiral (21), The bearing plate (30) is completely arranged inside the housing (100), and the bearing plate (30) and the bearing (31) are made of materials having thermal expansion coefficients that differ from each other by up to 20%, particularly up to 10%, particularly up to 5%.

2. 2. A displacement machine according to claim 1, characterized in that the bearing plate (30) is frictionally connected to the housing (100).

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

4. 4. The positive displacement machine according to claim 3, characterized in that the housing ring (31) has 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. 3. A displacement machine according to claim 1 or 2, characterized in that the bearing plate (30) is fixed in the drive housing (10).

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

7. 7. A displacement machine according to claim 1, wherein the bearing plate (30) is fixedly connected, in particular frictionally connected, to the counter spiral (25).

8. 8. The displacement machine according to claim 1, wherein the orbital displacement spiral (21) has a displacement spiral bottom (22) and a sealing element (24) is fixed in the displacement spiral bottom.

9. 9. The displacement machine according to claim 1, characterized in that a slide plate (33) is arranged between the bearing plate (30) and the track displacement spiral (21), in particular the displacement spiral bottom (22).

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

11. 11. A positive displacement machine according to claim 9 or 10, characterized in that the sealing element (24) is sealed against the slide plate (40).

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