SCROLL COMPRESSOR

Description

[0001] The invention relates to a scroll compressor according to the preamble of claim 1. The invention further relates to a vehicle air conditioning system and a motor vehicle with such a scroll compressor.

[0002] A scroll compressor of the type mentioned above is known, for example, from DE 10 2019 108 417 A1. This patent describes a scroll compressor that is particularly suitable for use in electric vehicles. In electric vehicles, the problem is that the absence of an internal combustion engine, which is used in conventional vehicles, makes noise from auxiliary components more prominent. This noise is mostly caused by structure-borne sound transmission from the auxiliary components. This is especially true for compressors of vehicle air conditioning systems, which, in conventional designs, are audible in electric vehicles and also perceptible due to their vibrations. Therefore, there is a need to reduce the vibrations and structure-borne sound transmission generated by the auxiliary components, especially scroll compressors.The aforementioned DE 10 2019 108 417 A1 provides a solution in which the rings of a so-called pin-ring system, which guides the orbiting displacement spiral, are dampened by a lubricant. Although the dampening already leads to a significant reduction in vibrations and noise emissions, further improvements are needed.

[0003] Document US 5,575,635 discloses a spiral compressor in which the base plate of the moving spiral is guided by four pins penetrating the base plate in an axial direction, thereby spanning a square.

[0004] In the well-known pin-ring system, the pins engaging with the rings are arranged to form a regular polygon. The polygon has interior angles that are identical and can be calculated using the following formula: a = n − 2 ⋅ 180 0 n

[0005] Against this background, the object of the present invention is to provide a scroll compressor that offers further improvements with regard to low vibration and quiet operation. Furthermore, the object of the invention is to provide a vehicle air conditioning system and a motor vehicle with such a scroll compressor.

[0006] According to the invention, this problem is solved with regard to the scroll compressor by the subject matter of claim 1, with regard to the vehicle air conditioning system by the subject matter of claim 7 and with regard to the motor vehicle by the subject matter of claim 8.

[0007] The invention is based on the concept of a scroll compressor comprising a housing with a housing cover and a housing partition, an electric drive unit connected to an eccentric bearing via a drive shaft with an axle, a movable displacement spiral rotatably connected to the eccentric bearing about an eccentric axis, and a stationary counter-spiral engaged with the displacement spiral. In the scroll compressor, the housing partition and the displacement spiral are arranged on a suction side, and the housing cover and the counter-spiral are arranged on a high-pressure side. Several cylindrical recesses are formed on the side of the displacement spiral facing the suction side.On the side of the housing partition facing the high-pressure side, pins are arranged such that they project into the cylindrical recesses and interact with them, thus forming a guide for the movable displacer spiral. Preferably, a ring element surrounding the pin is arranged in each cylindrical recess.

[0008] According to the invention, the pins span an imaginary polygon, wherein at least one interior angle of the polygon differs from any other interior angle and, optionally, from 120°. In particular, in the embodiment of the invention in which one interior angle differs from at least one other interior angle, equation 1 given above is not valid.

[0009] Essentially, in the invention, the pins are asymmetrically distributed. It has been shown that such an asymmetrical distribution of the pins leads to lower resonances and vibration amplifications. This significantly reduces the noise emissions of a scroll compressor. The scroll compressor is therefore particularly suitable as a quiet-running component in the air conditioning system of electric vehicles.

[0010] The transformation from combustion engines to electric drives in today's vehicles also leads to a saving of installation space. Electric motors simply require less space than combustion engines, allowing auxiliary components to be made larger. The newly available space also permits the use of larger scroll compressors, enabling an increase in the number of pins and associated ring elements. In particular, it's not just a matter of three, four, or five pins. Rather, it's conceivable that seven, eight, nine, or more pins could be used. Increasing the number of pins directly results in smoother operation, which further reduces noise emissions.

[0011] In a preferred embodiment of the invention, the recesses and / or the pins, in particular the ring elements, are provided with and / or contact a non-metallic material, preferably plastic. This further reduces vibrations, especially if the non-metallic material has damping properties. Suitable plastics can effectively provide such damping.

[0012] In the scroll compressor according to the invention, a pair of adjacent pins spans a pin pair angle around the axis of the drive shaft, wherein the pin pair angle of one pair differs from the pin pair angle of at least one other pair. In particular, the pin pair angle of one pair can be larger or smaller than the pin pair angle of at least one other pair by at least 1%, in particular by at least 2%, in particular by at least 5%, in particular by at least 10%, in particular by at least 20%, in particular by at least 40%, in particular by at least 50%.

[0013] Furthermore, the pins can be arranged on at least two pitch circles of different diameters around the axis of the drive shaft. In particular, a second pitch circle can be at least 1%, at least 2%, at least 5%, at least 10%, at least 20%, at least 40%, or at least 50% larger or smaller than a first pitch circle. The different pin pair angles and / or the different pitch circles result in an asymmetrical arrangement of the pins, which has proven to be particularly effective at reducing vibrations in practice. This specific arrangement of pins and associated recesses contributes significantly to the reduction of noise emissions.

[0014] In another preferred embodiment, the scroll compressor comprises a stator surrounding the drive shaft, in particular having twelve stator slots, a rotor with, in particular, ten rotor pole pairs, and preferably seven pins. Such a configuration has proven to be particularly effective in reducing vibrations and noise emissions.

[0015] In this context, it is particularly advantageous if the number of stator slots or rotor pole pairs is divisible by the number of pins with only a remainder.

[0016] Alternatively, it can be provided that the stator has 12 stator slots and the rotor has eight rotor pole pairs.

[0017] A secondary aspect of the invention relates to a vehicle air conditioning system with a scroll compressor as described above. A further secondary aspect relates to a motor vehicle with such a vehicle air conditioning system. The motor vehicle may preferably have at least a partially electric drive system.

[0018] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying schematic drawings. These show Fig. 1 a longitudinal sectional view through a scroll compressor according to a preferred embodiment according to the invention; Fig. 2 a cross-sectional view through a movable displacement spiral of a scroll compressor according to the invention. Fig. 1 , wherein the pins are arranged on pitch circles with different diameters; Fig. 3 a cross-sectional view through a displacement spiral of a scroll compressor according to a further embodiment, wherein the pins span a polygon having different interior angles; Fig. 4 a cross-sectional view through a displacement spiral of a scroll compressor according to the invention with four pins spanning a polygon with different interior angles; Fig. 5 a cross-sectional view through a displacement spiral of a scroll compressor according to a further preferred embodiment, wherein four pins are provided, one of which is arranged on a different pitch circle diameter; and Fig.6. A cross-sectional view of an example of a displacement spiral of a scroll compressor which is not part of the claimed invention, wherein four pins are provided which span a polygon with interior angles that are each different from 120°.

[0019] Fig. 1 Figure 10 shows a scroll compressor comprising a housing 11 with a housing cover 12 and a housing partition 13. The housing partition 13 extends over the inner diameter of the housing 10.

[0020] An electric drive unit 21 is arranged within the housing 10, comprising an electric motor with a stator 32 and a rotor 33. The rotor 33 is non-rotatably connected to a drive shaft 22. The drive shaft 22 extends through the housing partition 13 and has an axis A. The drive shaft 22 is further connected to an eccentric bearing 23 via an eccentric bolt 24. The eccentric bearing 23 comprises an axis EA, which is arranged eccentrically to the axis A of the drive shaft 22 and is therefore referred to as the eccentric axis EA.

[0021] The eccentric bearing 23 is mounted in a displacement spiral 14, so that the eccentric bearing 23 supports the displacement spiral 14. The displacement spiral 14 is movable and engages with a stationary counter-spiral 15.

[0022] The scroll compressor 10 generally comprises a high-pressure side HD and a suction side SA. The displacement spiral 14 separates the suction side SA, in which the drive unit 21 is also located, from the high-pressure side HD, which essentially comprises the counter spiral 15.

[0023] On the side of the displacement spiral 14 facing the suction side SA, several cylindrical recesses 16 are formed. As shown in Fig. 1 As can be clearly seen, a ring element 18 is embedded in each of the recesses 16. The ring element 18 essentially forms a cylindrical sliding surface for a pin 17 that engages in the recess 16. Several pins 17 are provided in total, which are rotationally fixed to the housing partition 13 and engage in the recesses 16 such that they are guided along the inner surfaces of the rings 18. This combination of pins 17 and ring elements 18 forms a guide for the displacement spiral 14, ensuring that the displacement spiral 14 performs an orbiting motion due to its eccentric excitation via the eccentric bearing 23.

[0024] Fig. 2 Figure 1 shows a cross-sectional view of the arrangement of the pins 17 within the recesses 16 in the displacer spiral 14. Specifically, a cross-sectional view through the displacer spiral 14 is shown. A dotted line also indicates the housing partition 13 located behind the displacer spiral 14 in the view. It can be seen that the displacer spiral 14 slides eccentrically on the housing partition 13.

[0025] In all embodiments, the pins 17 span a virtual polygon P, which is represented symbolically in the respective drawings. The polygon P comprises interior angles W1, W2, W3, W4, W5, and W6. Each pair of adjacent pins 17 forms a pair 26 to 31, with each pair spanning a pin-pair angle S1 to S6 around the axis A of the drive shaft 22. The vertices of the polygon P each lie on a central axis MS of the pin 17.

[0026] Similarly, in all embodiments, the pin 17 is arranged off-center in the respective recess 16. In particular, the pin 17 slides along an inner wall of a ring element 18, which is arranged within the recess 16. The recess 16 thus has a central axis MA, which is preferably arranged parallel to, but not coincident with, the central axis of the pin 17 in every state of the scroll compressor.

[0027] The examples of implementation according to Fig. 2 bis 6 differ in the specific number and arrangement of the pins 17.

[0028] Thus, in the embodiment according to Fig. 2 It is provided that five of the six pins 17 are arranged on a first pitch circle T1 with a first diameter, and the sixth pin 17 is arranged on a second pitch circle T2 with a second diameter. The second diameter is larger than the first diameter. This arrangement results in the polygon P, here a hexagon, no longer being regular, but having different interior angles W1 to W6. In particular, the interior angles W1, W2, and W6 are larger than the interior angles W3, W4, and W5.

[0029] The pin pair angles S1 to S6, however, can be equal. Essentially, it can be provided that the pin 17 located on the pitch circle T2 forms a line of symmetry with an opposing pin 17 on the pitch circle T1 for the remaining four pins 17. Overall, however, there is an asymmetry insofar as the pins 17 are not all arranged on the same pitch circle T1, T2. This type of asymmetry provides the advantage according to the invention, namely that vibrations and structure-borne noise transmission are reduced during the operation of the scroll compressor.

[0030] In the embodiment according to Fig. 3 Six pins 17 are also provided. The pins 17 are also arranged on the same pitch circle T. However, they form an irregular polygon P because the pin pair angles S1-S6 differ. Thus, two pins 17 form a pin pair 26, which forms a first pin pair angle S1 around the axis A of the drive shaft 22. The first pin pair angle S1 is larger than, for example, the pin pair angle S4, which is formed by the opposite pin pair 29 around the axis A of the drive shaft 22. Such an asymmetrical arrangement of pins 17 has also demonstrated a significant reduction in vibrations and noise emissions in scroll compressors.

[0031] In the embodiment according to Fig. 4 Four pins 17 are provided, which are guided in corresponding four recesses 16. The pins 17, with their central axes MS, define a polygon P, which is irregular. In particular, the polygon P forms an irregular quadrilateral. It can be seen that all pins 17 in the embodiment according to Fig. 4 are arranged on the same pitch circle T. However, the respective pin pairs 26 to 29 exhibit partially different pin pair angles S1 to S4. In particular, the first pin pair 26 spans a first pin pair angle S1 with the axis A of the drive shaft 22, which is larger than the other pin pair angles S2 to S4.

[0032] An alternative positioning of pins 17 is shown in the embodiment according to Fig. 5 shown. Here too, four pins 17 are provided, each guided in a recess 16. The pins 17, with their central axes MS, form an irregular quadrilateral, the irregularity of which in the embodiment shown is Fig. 5 This results in one pin 17 being arranged on a different pitch circle T2 than the other pins 17. Specifically, three of the pins 17 are arranged on a first pitch circle T1, the first pitch circle T1 extending concentrically around the axis A of the drive shaft 22 and having a first pitch circle diameter. The second pitch circle T2 has a second pitch circle diameter that is larger than the first pitch circle diameter. One of the four pins 17 is arranged on the second pitch circle T2.

[0033] Fig. 6Figure 1 shows an additional embodiment of a scroll compressor 10, not covered by the claims, wherein the scroll compressor 10 also has four pins 17 whose central axes MS define a polygon P. However, the polygon P is designed as a regular polygon. Specifically, the polygon P is a square. Crucially, for noise minimization and vibration reduction, the interior angle of the polygon P deviates from 120°. It has been shown that even such a deviation leads to smoother operation of the scroll compressor. Reference symbol list

[0034] 10 Scroll compressor 11 Housing 12 Housing cover 13 Housing partition 14 Displacement spiral 15 Counter spiral 16 Recess 17 Pin 18 Ring element 21 Drive unit 22 Drive shaft 23 Eccentric bearing 24 Eccentric bolt 26 - 31 Pin pair 32 Stator 33 Rotor HD High-pressure side SA Suction side A Axis EA Eccentric axis MA Center axis of recess 16 MS Center axis of pin 17 P Polygon spanned by pins 17 S1 - S6 Pin pair angle T, T1, T2 Pitch circle around axis A W1 - W6 Interior angle of polygon

Claims

1. A scroll compressor (10) comprising a housing (11) with a housing cover (12) and an intermediate housing wall (13), an electric drive unit (21), which is connected with an eccentric bearing (23) by a drive shaft (22) having an axis (A), a movable displacement coil (14) connected with the eccentric bearing (23) so that it can rotate around an eccentric axis (EA), and an immovable counter-coil (15) that engages with the displacement coil (14); wherein - the intermediate housing wall (13) and the displacement coil (14) are arranged on a suction side (SA) and the housing cover (12) and the counter-coil (15) are arranged on a high-pressure side (HD), - several cylindrical recesses (16) are formed on the side of the displacement coil (14) facing the suction side (SA), and - pins (17) are arranged on the side of the intermediate housing wall (13) facing the high pressure side (HD), such that they extend into the cylindrical recesses (16) and interact with them, thereby forming a guide for the movable displacement coil (14), and preferably - a respective ring element (18) that envelops the pin (17) is arranged in the cylindrical recesses (16), characterized in that the pins (17) form an imaginary polygon (P), wherein at least one interior angle (W1, W2, W3, W4, W5, W6) of the polygon (P) differs from another interior angle (W1, W2, W3, W4, W5, W6), wherein a pair (26-31) of neighboring pins (17) forms a pin pair angle (S1-S6) around the axis (A) of the drive shaft (22), wherein the pin pair angle (S1-S6) of one pair (26-31) differs from the pin pair angle (S1-S6) of at least one other pair (26-31), in particular is at least 1%, 2%, 5%, 10%, 20%, 40% or 50% larger or smaller.

2. The scroll compressor (10) according to claim 1, characterized in that three, four, five, seven, eight, nine or more pins (17) are provided.

3. The scroll compressor (10) according to claim 1 or 2, characterized in that the recesses (16) and / or the pins (17), in particular the ring elements (18), are provided with or contact a nonmetallic material, preferably plastic.

4. The scroll compressor (10) according to one of the preceding claims, characterized in that the pins (17) are arranged around the axis (A) of the drive shaft (22) on at least two pitch circles (T1, T2) of varying diameters, wherein in particular the second circular segment (T2) is at least 1%, 2%, 5%, 10%, 20%, 40% or 50% larger or smaller than the first circular segment (T1).

5. The scroll compressor (10) according to one of the preceding claims, characterized by a stator (32) that envelops the drive shaft (22) and in particular has twelve stator grooves, a rotor (33) with in particular ten rotor pole pairs, and preferably seven pins (17).

6. The scroll compressor (10) according to claim 5, characterized in that the number of stator grooves or rotor pole pairs can only be divided by the number of pins (17) with a remainder.

7. A motor vehicle air conditioning system, characterized by a scroll compressor (10) according to one of claims 1 to 6.

8. A motor vehicle, characterized by a motor vehicle air conditioning system according to claim 7.

9. The motor vehicle according to claim 8, which has an at least partially electric vehicle drive.