Balancing mechanism for scroll compressor

Abstract

A balancing mechanism for a positive displacement machine, in particular a scroll compressor, according to the spiral principle, wherein the balancing mechanism has a drive shaft (10), a first balancing element (20) and a second balancing element (30), wherein: the first balancing element (20) has a cylindrical hub section (21) and a first force transmission section (22), and is rotatably in contact with the drive shaft (10) via a first rotating shaft (11), and the second balancing element (30) is rotatably in contact with the drive shaft (10) via a second rotating shaft (12), and wherein the central axis (S) of the drive shaft (10) and the central axis (C) of the cylindrical hub section (21) are arranged on a first reference line (CS), and wherein the center of gravity J of the first balancing element (20) and the center of gravity K of the second balancing element (30) are arranged on a side of the first reference line (CS) different from the central axis (P) of the first rotating shaft (11).

Description

[0001] The invention relates to a positive displacement machine according to the spiral principle (Spiralprinzip). In particular, to a balancing mechanism for a scroll compressor and a positive displacement machine according to the spiral principle having such a balancing mechanism.

[0002] Scroll compressors are known from the prior art, which compress a fluid by guiding the fluid between two mutually nested positive displacement spiral elements and compressing the fluid therein. A scroll compressor has a fixed positive displacement spiral element and a movable, in particular orbiting positive displacement spiral element (orbitierend ), wherein compression chambers are formed between the spiral element walls, the volume of which changes due to the movement of the movable positive displacement spiral element. The fluid guided therein is compressed by this volume change.

[0003] In order to obtain a good compression function, it is important that the spiral element walls of the fixed positive displacement spiral element and the movable positive displacement spiral element, which delimit the compression chambers, abut each other well in a sealed manner. However, such sealing causes difficulties in practice. On the one hand, manufacturing tolerances may lead to unsealing. On the other hand or additionally, attention must be paid to the gas forces exerted on the two positive displacement spiral elements joined to each other by the compressed fluid. The gas forces may push the spiral element walls of the two positive displacement spiral elements joined to each other apart, so that the compression chambers are no longer sufficiently sealed. Thereby, gas may escape from the compression chambers, thereby reducing the gas forces and subsequently causing the spiral element walls to abut each other again. This interaction may lead to the generation of undesired noise, in particular vibrations, which as a whole interfere with the operation and efficiency of the scroll compressor.

[0004] The movable positive displacement spiral element is usually driven by a drive shaft, wherein the movable positive displacement spiral element is eccentrically mounted on the drive shaft. Therefore, the rotation of the drive shaft is converted into an orbiting movement of the movable positive displacement spiral element. For this purpose, a rotating shaft is provided on the drive shaft, which is arranged eccentrically with respect to the central axis of the drive shaft. The movable positive displacement spiral element is mounted on this rotating shaft.

[0005] To reduce vibrations arising from gas forces and manufacturing tolerances and to improve the sealing between the walls of the spiral elements, US4,824,346 A proposes a balancing mechanism. The known balancing mechanism includes a balancing mass that is eccentrically arranged on the rotational axis of a movable positive-displacement spiral element and can swing about this rotational axis. Due to the swinging movement automatically adjusted based on the centrifugal force, the gas forces and manufacturing tolerances are balanced, thereby improving the sealing of the compression chamber between the two positive-displacement spiral elements and thus increasing the efficiency of the scroll compressor. However, the disadvantage of this known solution is the relatively high balancing mass, which on the one hand requires a large amount of installation space in the scroll compressor and on the other hand can cause imbalance, which may lead to high noise generation due to the vibrations occurring especially in scroll compressors operating at different rotational speeds.

[0006] DE 10 2019 108 079 A1 counteracts these disadvantages by arranging a swinging balancing element such that the center of gravity of the balancing element is arranged on the same side of the common central plane of the drive shaft and the movable positive-displacement spiral element as the central axis of the rotational axis of the movable positive-displacement spiral element. In this way, additional torques are generated on the balancing element during operation, which cause the balancing of the manufacturing tolerances and gas forces. Therefore, the balancing mass of the balancing element can be reduced, thereby reducing the requirements for installation space and the occurrence of vibrations at different rotational speeds of the scroll compressor. However, it has been shown that this also has limitations, especially with regard to the minimum balancing mass still required to maintain the good effect of the balancing mechanism. Especially in scroll compressors operating in a wide rotational speed range, significant vibrations still occur.

[0007] Based on the above prior art, the object of the present invention is to provide a balancing mechanism for a positive-displacement machine according to the spiral principle, in particular a scroll compressor, which is conducive to further improving the efficiency of the positive-displacement machine according to the spiral principle and further reducing the occurrence of vibrations. In addition, the object of the present invention is also to provide a positive-displacement machine according to the spiral principle, in particular a scroll compressor, having such a balancing mechanism.

[0008] According to the present invention, this object is achieved in terms of the balancing mechanism by the following:

[0009] A balancing mechanism for a positive-displacement machine according to the spiral principle, the positive-displacement machine being in particular a scroll compressor, wherein the balancing mechanism has a drive shaft, a first balancing element and a second balancing element, wherein:

[0010] The first balancing element has a cylindrical hub section and a first force transmission section, and is rotatably in contact with the drive shaft via a first rotational axis; and

[0011] The second balancing element is rotatably in contact with the drive shaft via a second rotation axis.

[0012] And wherein the central axis S of the drive shaft and the central axis C of the cylindrical hub section are arranged on a first reference line CS, and wherein the center of gravity J of the first balancing element and the center of gravity K of the second balancing element are arranged on a side of the first reference line CS that is different from the central axis P of the first rotation axis.

[0013] Accordingly, the present invention is specifically based on the idea of providing a balancing mechanism for a positive-displacement machine, in particular a scroll compressor, according to the spiral principle, wherein the balancing mechanism has a drive shaft, a first balancing element, and a second balancing element. The first balancing element has a cylindrical hub section and a first force-transmitting section, and is rotatably in contact with the drive shaft via a first rotation axis. The second balancing element is rotatably in contact with the drive shaft via a second rotation axis. The central axis S of the drive shaft and the central axis C of the cylindrical hub section are arranged on a first reference line CS. The center of gravity J of the first balancing element and the center of gravity K of the second balancing element are arranged on a side of the first reference line CS that is different from the central axis P of the first rotation axis.

[0014] Preferably, the first rotation axis and the second rotation axis are each arranged eccentrically or centrifugally with respect to the central axis S of the drive shaft. The balancing elements can each be in direct or indirect contact with or connected to the drive shaft via their associated rotation axes. Thus, the rotation axes can each form a connecting link that establishes a connection between the respective balancing element and the drive shaft. However, an indirect connection via the rotation axes is not excluded, i.e., other components are involved in the connection or are arranged between the respective balancing element and the drive shaft.

[0015] Regarding the first balancing element, it is preferred that the hub section of the first balancing element is in contact with or connected to the drive shaft via the first rotation axis.

[0016] Accordingly, the present invention uses a second balancing element that can also swing during the operation of a positive-displacement machine according to the spiral principle. In this way, additional torques are generated that achieve an additional balance of the gas forces and manufacturing tolerances. Thus, by a corresponding design of the balancing mass and the position of the corresponding center of gravity, the balance of the gas forces and manufacturing tolerances can be adjusted more precisely. As a result, the balancing mechanism according to the present invention improves the smooth operation of a positive-displacement machine according to the spiral principle, especially even when the positive-displacement machine operates with a high speed difference. This increases the efficiency of the positive-displacement machine because the sealing between the positive-displacement spiral elements of the positive-displacement machine and thus the sealing of the compression chamber are ensured over a wide speed range.

[0017] The drive shaft can have a first axis of rotation at an end face, on which a first balancing element is mounted, the first balancing element having a cylindrical hub section and a first force transmission section. The drive shaft can also have a second axis of rotation, on which a second balancing element is mounted.

[0018] In a preferred embodiment of the invention, the hub section of the first balancing element has an eccentrically arranged mating hole, into which the first axis of rotation engages. In addition, the second balancing element can have a mating hole, into which the second axis of rotation engages. Preferably, there is a certain clearance between the mating hole and the first axis of rotation and / or between the mating hole and the second axis of rotation, such that the hub section can swing about the first axis of rotation, and the second balancing element can swing about the second axis of rotation. Thus, the connection between the first axis of rotation and the mating hole and the connection between the second axis of rotation and the mating hole are respectively form-locking (formschlüssig), but not force-locking (kraftschlüssig). Thus, a rotary sliding bearing is substantially formed between the mating hole and the first axis of rotation and between the mating hole and the second axis of rotation.

[0019] Alternatively, it can be provided that the first axis of rotation is firmly connected to the first balancing element, and the second axis of rotation is firmly connected to the second balancing element. In particular, the axes of rotation can be integrally formed with the associated balancing elements respectively. Thus, the balancing elements can each have pin extensions forming their respective axes of rotation. Preferably, the first axis of rotation, which can be arranged on the first balancing element, is eccentrically arranged relative to the hub section or the central axis of the hub section and is firmly connected to the hub section or integrally formed with the hub section. To allow rotational or pivoting movement of the balancing element, it is preferably provided that the drive shaft has corresponding blind holes, into which the axes of rotation engage. Thus, a first blind hole can be provided, into which the first axis of rotation engages. The second blind hole can accommodate the second axis of rotation. Preferably, the axes of rotation are rotatably mounted in the associated blind holes respectively. In this regard, a rotary sliding bearing is preferably present between the respective axis of rotation and the modified blind hole.

[0020] Overall, the first balancing element can be rotatably connected to the drive shaft via the first axis of rotation, wherein the first axis of rotation is rotationally fixed (drehfest) to the balancing element and rotatably connected to the drive shaft, or vice versa, rotationally fixed to the drive shaft and rotatably connected to the balancing element. The corresponding applies to the second balancing element, such that the second balancing element can be rotatably connected to the drive shaft via the second axis of rotation, wherein the second axis of rotation is rotationally fixed to the balancing element and rotatably connected to the drive shaft, or vice versa, rotationally fixed to the drive shaft and rotatably connected to the balancing element.

[0021] In terms of the compact structural form of the balancing mechanism, preferably, a second balancing element is arranged between the first balancing element and the drive shaft bearing on the scroll side. Here, in the longitudinal direction of the drive shaft, the respective sections of the first balancing element and the second balancing element can overlap, so that the structural dimensions or the structural height of the balancing mechanism are further reduced.

[0022] Preferably, the first balancing element and / or the second balancing element are each configured as one-piece or integral.

[0023] The first balancing element has a first force transmission section. It can also be provided that the second balancing element has a counterweight section and a second force transmission section, wherein the counterweight section and the second force transmission section are arranged on the same side of a second reference line PQ connecting the central axis P of the first rotating shaft and the central axis Q of the second rotating shaft.

[0024] In a preferred variant of the present invention, the second force transmission section of the second balancing element is in force-transmitting contact with the first force transmission section of the first balancing element. Thus, the deflection of the first balancing element caused by the centrifugal force is well transmitted to the second balancing element. This coupling of the balancing elements ensures a particularly smooth operation of the positive displacement machine.

[0025] The drive shaft can also have a spacer element that extends around the first rotating shaft and has a height that is greater than the thickness of the second balancing element in the engagement hole area. In this way, it is ensured that the first balancing element and the second balancing element are at different heights and cannot block each other.

[0026] To limit the swinging movement of the second balancing element, the first balancing element has a tab that rises towards the drive shaft, and this tab forms a stop for the counterweight section of the second balancing element.

[0027] A collateral aspect of the present invention relates to a positive displacement machine according to the spiral principle, in particular a scroll compressor, having the balancing mechanism described previously. Thereby, the object of the present invention in terms of positive displacement machines is achieved.

[0028] In the positive displacement machine according to the present invention, in a preferred variant, it is provided that the hub section has a rolling bearing that is connected to a movable, in particular orbiting, positive displacement spiral element during operation, wherein the movable positive displacement spiral element engages into a stationary positive displacement spiral element.

[0029] The present invention will be explained in more detail below with reference to schematic diagrams based on embodiments. In the drawings:

[0030] Figure 1Shows a longitudinal section of the balancing mechanism according to the present invention in the installed state within a positive displacement machine according to the spiral principle;

[0031] Figure 2 Shows according to Figure 1 A perspective top view of the balancing mechanism in the installed state;

[0032] Figure 3 Shows according to Figure 1 A perspective side view of the balancing mechanism, in which the rolling bearings of the movable positive displacement spiral of the positive displacement machine are additionally shown;

[0033] Figure 4 Shows according to Figure 1 A detailed perspective view of the balancing mechanism, in which the first balancing element is hidden to improve the display of the second balancing element;

[0034] Figure 5 Shows according to Figure 1 A perspective view of the balancing mechanism with two balancing elements;

[0035] Figure 6 Shows according to Figure 5 A side view of the balancing mechanism; and

[0036] Figure 7 Shows according to Figure 1 A geometric illustration of the positions of the central axes and centers of gravity of the different components of the balancing mechanism, in which the forces occurring are also shown.

[0037] In Figure 1 A cross-section of the balancing mechanism according to an embodiment of the present invention is shown. The balancing mechanism includes a drive shaft 10, which is mounted in a partition wall 42 of the compressor housing via a drive shaft bearing 34 on the scroll side. In addition, the drive shaft 10 is also mounted at the other end in a housing-side bearing, which is not shown for the sake of clarity in Figure 1 The partition wall 42 is generally fixedly arranged in the outer housing of a positive displacement machine (preferably a positive displacement machine according to the spiral principle, in particular a scroll compressor). The partition wall 42 separates the compression region within the positive displacement machine from the drive region. Most of the drive shaft 10 is arranged in the drive region, and the drive shaft 10 is mechanically driven or particularly preferably electrically driven, in particular by an electric motor. The electric motor is preferably also arranged in the drive region.

[0038] In the drive region, the drive shaft 10 also has two balance weights 14, 15. Here, the first balance weight 14 is arranged at the end of the drive shaft 10 facing away from the sealing region and is firmly connected to the drive shaft 10. The second balance weight 15 is arranged on the side of the drive shaft 10 facing the compression region, in particular in the immediate vicinity of the partition wall 42. The second balance weight 15 is also firmly connected to the drive shaft 10. Thus, the balance weights 14, 15 rotate with the drive shaft 10 during operation, thereby compensating for the imbalance.

[0039] The drive shaft bearing 34 is held in the partition wall 42. In particular, the drive shaft bearing 34 can be press-fitted (pressverbinden) to the partition wall 42, and the partition wall 42 has a corresponding recess for this purpose. In addition, the drive shaft 10 can be pressed into the drive shaft bearing 34. Preferably, the drive shaft bearing 34 is configured as a ball bearing.

[0040] At the end of the drive shaft 10 facing the compression region, two blind holes 16, 17 are provided. The first blind hole 16 houses the first rotating shaft 11. The second blind hole 17 houses the second rotating shaft 12. The first blind hole 16 preferably has a larger cross-sectional diameter than the second blind hole 17. The rotating shafts 11, 12 are respectively pressed into the corresponding blind holes 16, 17. Thus, there is a force-determined, rotationally fixed connection between the respective rotating shafts 11, 12 and the associated blind holes 16, 17.

[0041] In Figure 1 it can also be clearly seen that the blind holes 16, 17 or the rotating shafts 11, 12 are arranged eccentrically with respect to the central axis of the drive shaft 10. Thus, the rotating shafts 11, 12 are not coaxially aligned with the drive shaft 10, but are substantially offset eccentrically with respect to the central axis of the drive shaft 10.

[0042] The drive shaft 10 also has an extension forming a spacer element 13 in the region of the first rotating shaft 11. The spacer element 13 is integrally formed with the drive shaft 10. In particular, the spacer element 13 can be configured as an annular protrusion. The blind hole 16 extends through the spacer element 13, which preferably has a constant inner cross-sectional diameter over the entire length of the blind hole 16.

[0043] The second rotating shaft 12 protrudes beyond the longitudinal end of the drive shaft 10. However, the section of the second rotating shaft 12 protruding beyond the second blind hole 17 has a height which is preferably less than the height of the spacer element 13. The two rotating shafts 11, 12 respectively house balance elements 20, 30, which will be described in more detail below.

[0044] The first balancing element 20 is arranged on the first rotating shaft 11. The first balancing element 20 is pivotally mounted on the first rotating shaft 11. Specifically, the first balancing element 20 has a hub section 21 that is substantially cylindrical in shape. The hub section 21 includes a mating hole 23 into which the first rotating shaft 11 engages. There is a clearance between the first rotating shaft 11 and the mating hole 23 such that the hub section 21 or the first balancing element 20 can generally rotate or pivot about the first rotating shaft 11. In this regard, a sliding bearing substantially exists between the mating hole 23 and the first rotating shaft 11.

[0045] The hub section 21 extends into the rolling bearing 41. The hub section 21 is preferably press-fitted to the rolling bearing 41. The rolling bearing 41 is arranged in the rolling bearing seat of the movable positive displacement spiral member 40. Preferably, the rolling bearing 41 is formed by a ball bearing. The rolling bearing 41 is preferably press-fitted to the movable positive displacement spiral member 40.

[0046] In Figure 1 only the movable positive displacement spiral member 40 is partially shown. In any case, it can be seen that the movable positive displacement spiral member 40 has a spiral wall 44, but the spiral wall 44 is only sketched out in Figure 1 here. Generally, the height of the spiral wall 44 is greater than the height schematically shown here. The spiral wall 44 engages into the corresponding spiral wall of a relatively arranged fixed (especially position-fixed) positive displacement spiral member, which is not shown in Figure 1 either for the sake of clarity.

[0047] The movable positive displacement spiral member 40 is guided by a guide pin 43 that is firmly connected to the housing of the compressor. The guide pin engages into a corresponding guide chamber 45 of the movable positive displacement spiral member 40 and prevents the movable positive displacement spiral member 40 from rotating. More precisely, the movable positive displacement spiral member 40 should oscillate, that is, follow a predetermined, oscillatory movement path.

[0048] Figure 2 A top view of the balancing mechanism is shown. Figure 2The viewing direction basically extends from the compression chamber of the compressor towards the drive chamber of the compressor. In particular, the partition wall 42 into which the drive shaft bearing 34 is pressed can be seen. In the partition wall 42, balance elements 20, 30 are arranged in the space above the drive shaft bearing 34. The first balance element 20 has a hub section 21 in which a mating hole 23 is formed. It can be seen that the mating hole 23 is eccentrically aligned in the hub section 21. Therefore, the central axis of the first rotating shaft 11 does not extend aligned with the central axis of the cylindrical hub section 21, but has a distance from the central axis of the hub section 21. Preferably, the hub section 21 has a height corresponding to the height of the section where the first rotating shaft 11 protrudes beyond the first blind hole 16.

[0049] The first balance element 20 further includes a first force transmission section 22 which is integrally connected to the hub section 21. The first force transmission section 22 has a first recess 22a. The first recess 22a is configured to be substantially triangular, especially right-angled triangular. In this regard, the first recess 22a forms a region where the wall thickness of the first force transmission section 22 is reduced, which is used to reduce the weight of the first force transmission section 22. The first force transmission section 22 generally has an L shape and extends from the hub section 21 in the form of a radially outwardly projecting arm. The first balance element 20 is generally configured as a one-piece.

[0050] The second force transmission section 32 abuts against the first force transmission section 22 in a touching manner in the circumferential direction. The second force transmission section 32 is part of the second balance element 30. In addition, the second balance element 30 includes a counterweight section 31 which is arranged to be spaced apart from the second force transmission section 32 in the circumferential direction of the drive shaft bearing 34. Therefore, relative to the second rotating shaft 12, the counterweight section 31 and the second force transmission section 32 are arranged to form an obtuse angle with each other. The second balance element 30 is also generally configured as a one-piece.

[0051] In Figure 2 it can also be seen that the second balance element 30 is arranged between the drive shaft bearing 34 and the first balance element 20 in the longitudinal axial direction of the drive shaft 10. However, at least in the force transmission sections 22, 32, there is an overlap in the longitudinal axial direction of the drive shaft 10 such that the force transmission sections 22, 32 of the two balance elements 20, 30 can abut against each other. Here, the force transmission sections 22, 32 abut against each other in the circumferential direction or the rotational direction of the drive shaft 10. In the longitudinal axial direction of the drive shaft 10, there is preferably no contact between the balance elements 20, 30. More precisely, the balance elements 20, 30 should be able to swing independently of each other around their respective rotating shafts 11, 12.

[0052] In Figure 2It can also be seen that the counterweight section 31 of the second balancing element 30 substantially forms a thickened portion, which also slightly overlaps with the first balancing element 20 in the longitudinal axial direction. This enables the installation of the second balancing element 20 to save space, and the mass required for compensating the imbalance can be placed in the counterweight section 31 simultaneously.

[0053] The connecting arm to the second force transmission section 32 includes a second recess 32a, and the second recess 32a also forms a region where the wall thickness of the second balancing element 30 is reduced. In this way, materials are saved in the region of the second force transmission section 32 and thus mass is saved, which provides an improvement for the operation of the balancing mechanism.

[0054] Figure 3 A perspective side view of the balancing mechanism is shown again. In particular, the design of the balance weights 14, 15 and their position and alignment on the drive shaft 10 can be clearly seen. The balancing elements 20, 30 are located at the longitudinal ends of the drive shaft 10. The rolling bearings 41 are also shown, and the rolling bearings 41 are connected to the longitudinal ends of the drive shaft 10 after the balancing elements 20, 30.

[0055] Specifically according to Figure 4 it can be clearly seen the design and position of the second balancing element 30. The second balancing element 30 has a mating hole 33, and the mating hole 33 is preferably configured as a through opening. The mating hole 33 houses the second rotating shaft 12. Preferably, there is a gap between the mating hole 33 and the second rotating shaft 12, so that a sliding bearing connection substantially exists between the second rotating shaft 12 and the mating hole 33. In this way, the second balancing element 30 can swing around the second rotating shaft 12.

[0056] In the region of the counterweight section 31, a third recess 31a can also be seen. The third recess 31a reduces the material of the counterweight section 31 in some areas, thereby obtaining an improved mass distribution in the counterweight section 31. This mass distribution has proven to be particularly advantageous for reducing vibrations in the scroll compressor. In Figure 4 It can also be seen that the spacer element 13 has a height that is greater than the thickness of the second balancing element 30 in the region of the extension of the drive shaft 10. This ensures that the first balancing element 20 located on the first rotating shaft 11 and abutting against the spacer element 13 maintains a certain distance from the second balancing element 30 in the longitudinal axial direction of the drive shaft 10.

[0057] In Figure 5 and Figure 6It can also be seen that the first balancing element 20 has a tab 24 which extends towards the drive shaft 10 in the longitudinal axial direction of the drive shaft 10. The tab 24 is arranged on the outer side surface of the first balancing element 20 and extends substantially such a distance that it extends around the hub section 21 to the first force transmission section 22. The tab 24 forms a stop 25 in the region opposite to the first force transmission section 22. The stop 25 overlaps with the counterweight section 31 of the second balancing element 30 in the longitudinal axial direction of the drive shaft 10, so that the counterweight section 31 can be stopped on the stop 25. Therefore, the relative vibration between the first balancing element 20 and the second balancing element 30 is restricted. Substantially, the second balancing element 30 can only swing within a range relative to the first balancing element 20, and this range is restricted by the stop 25 on the one hand and by the first force transmission section 22 on the other hand.

[0058] For the particularly advantageous smooth operation of the invention of a positive displacement machine (in particular a scroll compressor), the positions of the central axes and the centers of gravity of the different components of the balancing mechanism are very important. Such a special arrangement of the central axis or the axis of rotation and the center of gravity will be elaborated in detail below based on the Figure 7 geometric illustration.

[0059] In Figure 7 the cross-sections of the drive shaft 10, the first rotating shaft 11, the second rotating shaft 12 and the hub section 21 are represented by circles. The other two circles represent the respective masses of the force transmission sections 22, 32.

[0060] The drive shaft 10 has a central axis S. The hub section 21 has a central axis C. In Figure 7 it can be seen that the central axis C of the hub section 21 is arranged eccentrically with respect to the central axis S of the drive shaft 10. The line connecting the central axes C, S of the drive shaft 10 and the hub section 21 is called the first reference line CS.

[0061] The first rotating shaft 11 has a central axis P. The second rotating shaft 12 has a central axis Q. The second reference line PQ extends through the central axes P, Q of the rotating shafts 11, 12.

[0062] The first balancing element 20 has a center of gravity J shown in Figure 7 . It can also be seen that the centrifugal force F acting on the center of gravity J CJ .

[0063] The second balancing element 30 has a center of gravity K, and the center of gravity K and the centrifugal force F acting on it CK together in Figure 7As shown. When observing the first reference line CS, it can be seen that the central axis P of the first rotating shaft 11 is arranged on one side of the first reference line CS, while the center of gravity J, K of the balancing elements 20, 30 are arranged on the other side of the first reference line CS. Therefore, this arrangement is significantly different from the prior art according to DE 10 2019108 079A1, in which the center of gravity of the balancing element and its rotational central axis are arranged on the same side of the first reference line. That is, in the prior art, the central axis P and the center of gravity J are on the same side of the first reference line CS.

[0064] Referring to the second reference line PQ connecting the central axes of the rotating shafts 11, 12, it can be seen that the center of gravity K of the second balancing element 30 is arranged on one side of the second reference line PQ, while the center of gravity J of the first balancing element 20 is arranged on the other side of the second reference line PQ. However, with respect to the second reference line PQ, the central axis of the hub section 21 of the first balancing element 20 and the center of gravity K of the second balancing element 30 are arranged on the same side. In contrast, the central axis S of the drive shaft 10 and the center of gravity J of the first balancing element 20 are arranged on the same side of the second reference line PQ.

[0065] In other words, the central axis of the hub section 21 of the first balancing element 20 and the central axis of the drive shaft 10 are on different sides of the second reference line PQ. Similarly, the centers of gravity J, K of the balancing elements 20, 30 are on different sides of the second reference line PQ. The central axis S of the drive shaft 10 and the center of gravity J of the first balancing element 20 are on one side of the second reference line PQ, while the central axis C of the hub section 21 and the center of gravity K of the second balancing element 30 are arranged on the other side of the second reference line PQ.

[0066] It can also be seen in Figure 7 that the distance from the center of gravity K of the second balancing element 30 to the second reference line PQ is significantly greater than the distance from the center of gravity J of the first balancing element 20 to the second reference line PQ. The same applies to the reference to the first reference line CS. The distance from the center of gravity K of the second balancing element 30 to the first reference line CS is greater than the distance from the center of gravity J of the first balancing element 20 to the first reference line CS. This is preferably achieved by arranging the counterweight section 31 and the force transmission section 32 of the second balancing element 30 on the same side of the second reference line PQ. Preferably, the counterweight section 31 and the second force transmission section 32 of the second balancing element 30 are aligned and arranged such that they are completely arranged on one side of the second reference line PQ.

[0067] To illustrate the mechanical interaction between the balancing elements 20, 30, the force F Figure 7 is also shown in N and the force F NGenerated by the contact of the force transmission sections 22, 32. Therefore, during the operation of the balancing mechanism, the first force transmission section 22 transmits a force to the second force transmission section 32, and the second force transmission section 32 generates a corresponding reaction force. Preferably, the force transmission sections 22, 32 are configured such that the force and the reaction force are balanced with each other.

[0068] List of reference signs

[0069] 10 Drive shaft

[0070] 11 First rotating shaft

[0071] 12 Second rotating shaft

[0072] 13 Spacer element

[0073] 14 First balance weight

[0074] 15 Second balance weight

[0075] 16 First blind hole

[0076] 17 Second blind hole

[0077] 20 First balance element

[0078] 21 Hub section

[0079] 22 First force transmission section

[0080] 22a First recess

[0081] 23 mating hole

[0082] 24 Tab

[0083] 25 Stop

[0084] 30 Second balance element

[0085] 31 Counterweight section

[0086] 31a Third recess

[0087] 32 Second force transmission section

[0088] 32a Second recess

[0089] 33 Engagement hole

[0090] 34 Drive shaft bearing

[0091] 40 Movable positive displacement helix

[0092] 41 Rolling bearing

[0093] 42 Partition wall

[0094] 43 Guide pin

[0095] 44 Spiral part wall

[0096] 45 Guide chamber.

Claims

1. A balancing mechanism for a positive displacement machine according to the spiral principle, wherein, The balancing mechanism has a drive shaft (10), a first balancing element (20) and a second balancing element (30), wherein: The first balancing element (20) has a cylindrical hub section (21) and a first force transmission section (22), and is rotatably in contact with the drive shaft (10) via a first rotating shaft (11). The hub section (21) has a mating hole (23) arranged eccentrically, and the first rotating shaft (11) engages into the mating hole; and The second balancing element (30) is rotatably in contact with the drive shaft (10) via a second rotating shaft (12), and the second balancing element (30) has a second force transmission section (32), wherein the first force transmission section (22) and the second force transmission section (32) are in contact with each other in the circumferential direction of the drive shaft (10), and wherein the central axis S of the drive shaft (10) and the central axis C of the cylindrical hub section (21) are arranged on a first reference line CS, and wherein the center of gravity J of the first balancing element (20) and the center of gravity K of the second balancing element (30) are arranged on a side of the first reference line CS different from the central axis P of the first rotating shaft (11).

2. The balance mechanism according to claim 1, characterized in that The positive displacement machine is a scroll compressor.

3. The balance mechanism according to claim 1, characterized in that, The second balancing element (30) has a mating hole (33), and the second rotating shaft (12) engages into the mating hole.

4. The balance mechanism according to claim 2, characterized in that, The second balancing element (30) has a mating hole (33), and the second rotating shaft (12) engages into the mating hole.

5. The balance mechanism according to any one of claims 1-4, characterized in that, The first rotating shaft (11) is fixedly and eccentrically connected to the hub section (21), and is rotatably mounted in a first blind hole (16) of the drive shaft (10).

6. The balance mechanism according to claim 5, characterized in that, The first rotating shaft (11) is integrally and eccentrically connected to the hub section (21).

7. The balance mechanism according to any one of claims 1-4 and 6, characterized in that The second rotating shaft (12) is fixedly connected to the second balancing element (30), and is rotatably mounted in a second blind hole (17) of the drive shaft (10).

8. The balance mechanism according to claim 7, characterized in that The second rotating shaft (12) is integrally connected to the second balancing element (30).

9. The balance mechanism according to any one of claims 1-4, 6 and 8, characterized in that, The second balancing element (30) is arranged between the first balancing element (20) and a drive shaft bearing (34).

10. The balance mechanism according to any one of claims 1-4, 6 and 8, characterized in that, The second balancing element (30) further has a counterweight section (31), and the counterweight section and the second force transmission section are arranged on the same side of a second reference line PQ connecting the central axis P of the first rotating shaft (11) and the central axis Q of the second rotating shaft (12).

11. The balance mechanism according to claim 10, characterized in that, The second force transmission section (32) of the second balancing element (30) is in force-transmitting contact with the first force transmission section (22) of the first balancing element (20).

12. The balance mechanism according to any one of claims 1-4, 6, 8 and 11, characterized in that, The first balancing element (20) and the second balancing element (30) are each configured as a one-piece.

13. The balance mechanism according to any one of claims 1-4, 6, 8, and 11, characterized in that, The first balancing element (20) and the second balancing element (30) are each configured as an integral body.

14. The balance mechanism according to any one of claims 3-4, characterized in that, The drive shaft (10) has a spacer element (13) which extends around the first axis of rotation (11) and has a height which is greater than the thickness of the second balancing element (30) in the region of the engagement bore (33).

15. The balance mechanism according to claim 10, wherein The first balancing element (20) has a tab (24) which rises towards the drive shaft (10), and the tab forms a stop (25) for a counterweight section (31) of the second balancing element (30).

16. The balance mechanism according to claim 12, characterized in that, The first balancing element (20) has a tab (24) which rises towards the drive shaft (10), and the tab forms a stop (25) for a counterweight section (31) of the second balancing element (30).

17. The balance mechanism according to claim 13, characterized in that The first balancing element (20) has a tab (24) which rises towards the drive shaft (10), and the tab forms a stop (25) for a counterweight section (31) of the second balancing element (30).

18. The balance mechanism according to claim 14, wherein The first balancing element (20) has a tab (24) which rises towards the drive shaft (10), and the tab forms a stop (25) for a counterweight section (31) of the second balancing element (30).

19. A positive-displacement machine according to the screw principle, having a balancing mechanism according to any one of claims 1 - 18.

20. The positive displacement machine according to claim 19, wherein, The positive-displacement machine is a scroll compressor.

21. The positive displacement machine according to claim 19 or 20, characterized in that, The hub section (21) carries a rolling bearing (41) which is connected to a movable positive-displacement spiral member (40), wherein the movable positive-displacement spiral member (40) engages into a stationary positive-displacement spiral member.

22. The positive displacement machine according to claim 21, wherein, The movable positive-displacement spiral member (40) is orbiting during operation.

Images