Easily removable arrangement of an outer part that surrounds an inner part

Abstract

The invention relates to a component assembly (19) that comprises a first part (3) and a second part (6, 13, 14, 15, 16). The second part (6, 13, 14, 15, 16) encompasses the first part (3). The first part (3) and the second part (6, 13, 14, 15, 16) are connected to each other by a friction-type connection. The second part (6, 13, 14, 15, 16) comprises at least one recess (7) neighbouring the contact surface of the first part (3) and the second part (6, 13, 14, 15, 16).

Description

[0001] DESCRIPTION

[0002] TITLE: Easily removable arrangement of an outer part that surrounds an inner part

[0003] The invention relates to a component assembly, the component assembly comprising a first part and a second part, wherein the second part encompasses the first part at least partially, and wherein the first part and the second part are connected to each other by a friction-type connection.

[0004] The invention further relates to an electric motor and / or to a compressor device.

[0005] In essentially all types of technology and designs of machinery, various parts have to be connected to each other. Consequently, a wide variety of possible connection techniques are known in the state of the art. These various connection techniques can be generally classified into three types: form-fit connections, positive substance lock connections and friction-type connections, where combinations of two or even all three basic classes are sometimes employed.

[0006] Generally speaking, the connection technique that is employed depends on the requirements of the respective piece of machinery. For example, the connection strength, the durability of the connection, the environment in which the connection is employed, and also the cost for providing the connection are factors that are relevant for the choice of the connection technique. Only for completeness, it is to be noted that the aforesaid considerations are only some examples out of a wide field of possible considerations. A particular type of such possible considerations is the reversibility of the respective connection. Sometimes the respectively connected parts have to be disconnected from each other, for example for maintenance, for repairing faulty parts during manufacture of the device, for correcting displacement errors during manufacture, or the like.

[0007] Quite often the complexity and the cost associated with two parts that are to be connected to each other is highly different. I.e. one of the parts is quite expensive, while the other one is very cheap, as compared to the first one. Then it can be tolerated to damage or even destroy the cheaper part, while the more expensive part should remain as undamaged as possible during the disassembly process.

[0008] The reversibility of the connection became quite important in recent years, as there is a global trend to increase the reusability and recyclability of parts and materials. From a financial point of view, it is beneficial for the manufacturers to increase the reusability and recyclability of parts and materials, as it directly lowers the cost of manufacturing (e.g. by reusing a part without a need to buy a new one). Consequently, the market price of the product may be lowered and the market share may be increased.

[0009] An example for such a situation exists in the field of spindle devices, like electric motors, electric generators, compressors, or hydraulic motors: the rotor of the respective spindle device usually shows a comparatively large number of attached subassemblies, so that the respective rotor part is quite expensive. Additionally or alternatively, the respective rotor quite often comprises expensive raw materials, like rare earth elements or the like. This rotor is assembled within a bearing of a corresponding housing. To avoid an axial movement of the two parts, usually so-called retainers (essentially some washer type members / collar-like members) are used. Although they inhibit an axial movement, they nevertheless allow a rotational movement of the respective rotor.

[0010] A usual attachment technique for the retainer member on the rotor and / or on the shaft is by means of press-fit or shrink-fit attachment. Here, the retainer is pushed onto the rotor / shaft by applying mechanical forces (axially aligned mechanical forces). In the case of shrink-fit attachment techniques (in an effort to reduce the occurring mechanical forces), the retainer is initially heated before the actual attachment, so that thermal expansion increases the tolerances between the respective parts, thus reducing the attachment forces that are necessary (while typically a certain amount of pushing force in the axial direction is still needed).

[0011] Only for completeness, the afore described situation not only occurs for retainer members, but also for other types of parts like counterweights or the like.

[0012] Now the situation might occur that the attachment process was not sufficiently precise, or that some other type of fault is detected (requiring removal of the retaining member, counterweight or the like). Then, it is necessary to remove the part, preferably while inducing as little damage to the shaft, the rotor and / or other neighbouring parts as possible. This can be performed by pulling off the respective member. However, in particular in the case that a shrink-fit attachment technique has been used (with thermal expansion prior to placing the member on the rotor), a damage of the shaft is quite often unavoidable.

[0013] Therefore, it was already suggested to cut the retainer or counterweight, so that it can be easily removed from the rotor. However, such a cut has to be performed very precisely to not damage the rotor and / or the shaft. This is accordingly time-consuming and expensive and hence accordingly undesirable. It is therefore obvious that there is a desire in the technology to propose an improved component assembly, in which one of the two connected parts of a friction-type connection component assembly can be removed from the other part, without damaging the other part (where it is allowed to destroy the first part).

[0014] It is therefore an object of the present invention to suggest a component assembly, comprising a first part and a second part, wherein the second part encompasses the first part at least partially, and wherein the first part and the second part are connected to each other by a friction-type connection, so that the component assembly is improved over component assemblies of this type that are known in the state of the art.

[0015] It is another object of the invention to suggest an electric motor and / or a compressor device, comprising a component assembly of the afore mentioned type that is improved over electric motors and compressor devices, as they are known in the state of the art.

[0016] A component assembly, an electric motor and / or a compressor device according to the present disclosure solve(s) at least one of these objects.

[0017] It is suggested to design a component assembly that comprises a first part and a second part, wherein the second part encompasses the first part at least partially, and wherein the first part and the second part are connected to each other by a friction type connection in a way that at least one of the first part and the second part comprises at least one recess neighbouring the contact surface of the first part and the second part.

[0018] Usually, the first part and the second part are more or less rotationally symmetric (including an n-count symmetry; although this is not necessarily required; as an example, triangular, rectangular, quadratic, pentagonal, hexagonal, heptagonal, octagonal, etc. shaped designs are possible as well), in particular in the region, in which the respective parts contact each other (which may relate in particular to a radial and / or an axial position; “radial” may be particularly interpreted as the outer surface part of the first part and / or the inner surface part of the second part).

[0019] Typically, the second part shows a - typically significantly - smaller axial extent, as compared to the first part, although this is not necessarily required.

[0020] When talking about a partial encompassing of the first part by the second part, this is usually to be interpreted in a way that a friction-type connection may be effectuated and may be self-supporting (self-holding) itself. As an example, the second part should encompass the first part by at least 190°, 200°, 210°, 220°, 230°, 240°, 250°, 260°, 270°, 280°, 290°, 300°, 310°, 320°, 330°, 340° or 350° up to 200°, 210°, 220°, 230°, 240°, 250°, 260°, 270°, 280°, 290°, 300°, 310°, 320°, 330°, 340°, 350° or 360°. It is to be noted that encompassing does not necessarily mean that a contact between the first part and the second part is actually present over the whole encompassing range. Indeed, this is actually typically not the case. Usually, a (possibly accumulated) non-contacting area of at least 1 °, 2°, 3°, 4°, 5°, 10°, 15°, 20°, 30°, 40°, 50° and up to 5°, 10°, 20°, 30°, 40°, 45°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, 180°, 210°, 240°, 270°, 300°, 330°, 340°, or 350° may be foreseen. It is to be noted that the at least one recess that neighbours the contact surface of the first part and the second part will usually constitute such a non-contacting area (although this is not necessarily the case, in particularly not necessarily the case over the whole axial extent of the contacting region of the first part and the second part. When talking about a friction-type connection, this does not exclude the possibility that additional connection types are employed. In particular, a (partial) positive form locking connection and / or a (partial) positive substance locking connection might be additionally employed. Nevertheless, usually only a friction-type connection is employed, at least for the major part of the contacting area, in particular for at least 70%, 80%, 90% or 95% of the contacting area.

[0021] By providing at least one recess in at least one of the first part and the second part in a region that neighbours the contact surface of said first part and said second part, it is surprisingly simple to disconnect the first part and the second part by cutting or splitting the second part at or in the vicinity of the respective recess (and usually more or less destroying the second part to an extent that it cannot be reused; instead it is to be replaced by a similar or identical second part), without damaging the first part. This is because the recess provides for an adequate tolerance and / or safety zone I volume, in particular a tolerance and / or safety zone, in which a cutting device may be moved without removing material from the first part (and possibly from the second part). It is to be noted that the at least one recess might be provided in the first part, the second part, or in both parts. If a recess is provided in both parts, those recesses may or may not be aligned in a rotational direction.

[0022] The at least one recess that neighbours the contact surface of the first part and the second part is typically arranged and aligned in a way that it has at least an axial component (i.e. the direction of the recess and of the axial direction are not perpendicular to each other). Preferably, the recess encloses an acute angle with the axial direction. As an example, the angle should be smaller than 60°, 50°, 45°, 40°, 30°, 20°, 10°, 5°, 4°, 3°, 2° or 1 °. More preferably, the direction of the recess and the axial direction should be essentially identical.

[0023] It is to be noted that at first hand providing a recess might cause an imbalance in masses, thus creating a disadvantage. However, such an imbalanced mass may be accounted for by appropriately shaping one or both of the two parts, in particular of the part that comprises the recess and / or of the second part. Based on geometrical considerations of the component assembly, typically the first part may be addressed as an inner part, while the second part may be addressed as an outer part (or vice versa).

[0024] Preferably, it is suggested to design and arrange the component assembly in a way that the second part fully encompasses the first part in a circumferential way / direction. This may be realised by a ring-like design of (parts of) the second part / the outer part. This way, usually a particularly strong friction-type connection can be realised. It is to be noted that a full encompassing might be present for the full axial extent of the first part and / or of the second part. However, it might be present for only a part of the axial extent of the first part and / or the second part (for example between 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% up to 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 100%; usually with respect to the part with the smaller axial extent).

[0025] In particular, the component assembly might be designed and arranged in a way that at least one of the first part and the second part (preferably both parts) are designed in an elongated way. Preferably, at least one of the first part and the second part (preferably both) are designed in an axially elongated way. Using such a design I arrangement of the component assembly, the presently disclosed suggestion may show its characteristics and advantages in a particularly profound way. In particular, such an elongated design / axially elongated design is particularly versatile for compressors, hydraulic motors, electric motors, electric generators, general spindle type devices and the like. In particular, the first part / inner part might be a rotor, a shaft or the like, while the second part / outer part might be a holding member, a retainer member, a counterweight, or the like (including a combination of features as well).

[0026] It is further suggested to design and arrange the component assembly in a way that the friction-type connection of the at least two parts acts in the axial direction. Additionally or alternatively, it is suggested to design and arrange the component assembly in a way that in a radial and / or a tangential direction the at least two parts are connected by a positive form lock connection. Those designs and arrangements (possibly separately, but in particular in combination) will typically be realised due to the very geometric setup of the component assembly for various arrangements and / or designs, in particular for (axially) elongated designs and / or for partially and / or fully encompassing designs, in particular for the aforementioned designs.

[0027] Yet further, it is suggested to design and arrange the component assembly in a way that the first part comprises a rod-like section and / or is essentially shaped as a rod. Additionally or alternatively, the component assembly may be designed and arranged in a way that the second part comprises a ring-like section and / or a barrel-like section. In particular, the component assembly might be designed and arranged in a way that the second part is essentially ring-like shaped and / or cylinder barrel-like shaped. Such designs and arrangements are already used for parts of component assemblies / component assemblies as they are known in the state of the art. Therefore, a replacement of already known component assemblies (or parts thereof) by the presently suggested component assembly may be particularly simple, increasing the acceptance of the presently disclosed component assembly. Furthermore, such shapes are typically used for rotating device, like the already mentioned devices (electric motors, electric generators, compressors, spindle devices and the like).

[0028] It is to be noted that the dimension of the contacting surfaces of the components are generally constant along the axial direction. However, a tapering design (in particular a Morse type tapering design) might be present. However, in particular the outer surface of the outer part / the second part might show a varying shape, like a barrel-like shape (convex outer shape), or on the contrary a hyperbolic shape (concave outer shape). An appropriate choice might be made by a person skilled in the art, in particular based on stability considerations.

[0029] Yet further, it is suggested to design and arrange the component assembly in a way that at least one recess is arranged in the second part, wherein preferably the majority, more preferably (essentially) all recesses are arranged in the second part. This way, only the outer part / second part needs to be modified over already present designs. This may facilitate the migration to the presently proposed design. It is to be noted that the second part is usually a cheap part and can easily be dispensed with. Therefore, some present stock may even be discarded or recycled without inducing a major financial loss. Even further, with the presently suggested design, any imbalanced masses (due to the presence of the recesses) can be easily corrected for by an appropriate reshaping of the second part or the like.

[0030] Yet further, it is suggested to design and arrange the component assembly in a way that the at least one recess is arranged on a radially inner surface of the second part.

[0031] Even further, it is suggested to design and arrange the component assembly in a way that at least two recesses, in particular at least two recesses in the second part, are arranged at an angle of at least 90°, 100°, 110°, 120°, 130°, 135°, 140°, 150°, 160°, or 170°. Preferably the angle may be (essentially) 180°. This way, by providing two (or more) cuts at the appropriate positions in the vicinity of the recesses, the second part can be very easily dismounted from the first part. In particular, the second part may even more or less fall apart without necessitating the application of any significant force (in particular in a radial and / or an axial direction). This is of course particularly advantageous. Furthermore, at an angle of essentially 180°, the imbalanced masses that are induced by the recesses sort of self-balance themselves due to their symmetric arrangement. It is to be noted that in case n recesses are used, the respective recesses should be arranged at an angle of 360° / n between two neighbouring recesses.

[0032] Yet further, it is suggested to design and arrange the component assembly in a way that at least one recess has a shape that is taken from the group comprising V-shaped recesses, rectangular recesses, semi-circular recesses and rounded recesses. Such designs have shown to be particularly advantageous in first experiments with prototypes of the component assembly. It is to be noted that in case a plurality of recesses is used, the recesses may show (in part) the same shape and / or (in part) different shapes.

[0033] Even further it is suggested to design and arrange the component assembly in a way that at least one, preferably a plurality, even more preferably (essentially) all recesses extend over essentially the (full) axial extent of the second part. In particular, if at least one recess is provided in the first part, one may provide a “safety margin” in a way that the axial extent of the respective recess is larger than the axial extent of the second part. Using this design, by providing a cutting process, the two parts of the component assembly may be easily dismounted from each other with very small (if any) forces, in particular in the radial and / or axial direction.

[0034] Yet further, it is suggested to design and arrange the component assembly in a way that the first part and the second part of are assembled together via a shrink-fit or a press-fit connection. This way, the presently disclosed component assembly may show its intrinsic characteristics and advantages particularly well. Only as a matter of completeness: shrink-fit connections are usually performed in a way that one (or both) parts are thermally treated so as to shrink / expand them in a way that the tolerance between the two parts increases. Typically, the outer part (second part) will be heated. Additionally or alternatively, the inner part (first part) might be cooled. Further, it is suggested to design and arrange the component assembly in a way that the first part is designed and arranged as a compressor shaft or as an electric motor shaft. Additionally or alternatively, the second part may be designed and arranged as a shaft stopper, as a rotor stopper, as a retaining member and / or as a counterweight.

[0035] This way, again, the presently disclosed component assembly may show its intrinsic features and characteristics and advantages particularly well.

[0036] Even further, it is suggested to design and arrange the component assembly in a way that the second part has a shortened axial extent in the vicinity of at least one recess. Such a design may decrease the cutting requirement, therefore facilitating and / or accelerating a dismounting of the two parts.

[0037] Even further, an electric motor and / or a compressor device is suggested, wherein the respective motor / device comprises at least one component assembly according to any of the preceding claims. This way, the respective electric motor and / or compressor device may show a particularly advantageous design. In particular, it may show the same characteristics and advantages as already described, at least in analogy. Furthermore, the respective electric motor / compressor device may be modified in the sense of the present disclosure, at least in analogy, as well. This will result in appropriate characteristics and advantages.

[0038] Further advantages, features, and objects of the invention will be apparent from the following detailed description of the invention in connection with the associated drawings, wherein the drawings show:

[0039] Fig. 1 : a schematic cross-section through a possible embodiment of a compressor for a refrigerator; Fig. 2: an enlarged schematic cross-section of a section of the compressor according to Fig. 1 , showing a bearing section of the rotor shaft;

[0040] Fig. 3: a possible embodiment of a retaining member that is used in Figs. 1 and 2 in schematic, perspective view;

[0041] Fig. 4: a schematic top view on a variation of a retaining member according to Fig. 3;

[0042] Fig. 5: a further modification of a retaining member according to Figs. 3 and 4 in schematic top view;

[0043] Fig. 6: three possible embodiments of recesses that may be used for a component assembly according to the present disclosure;

[0044] Fig. 7: a possible embodiment of a counterweight according to the present disclosure in a schematic perspective view;

[0045] Fig. 8: a variation of a possible embodiment of a counterweight according to the present disclosure in a schematic perspective view.

[0046] Fig. 1 shows a schematic cross-sectional view through a refrigerant compressor 1 . Such a refrigerant compressor 1 is a possible embodiment of a spindle device, for which a component assembly 19 according to the present disclosure may be advantageously used. The compressor 1 may be used to pump the refrigerant of a refrigerator. However, it is to be noted that various other designs of spindle devices might be employed, like electric motors, electric generators, fluid motors or the like.

[0047] The compressor 1 comprises a housing 2 and a shaft 3 that is rotating relative to the housing 2. As it is known in the prior art as such, various parts are attached to the shaft 3. Briefly speaking, a compression unit 4 is connected to the shaft 3 in a torque-proof way. The compression unit 4 presently comprises a fixed scroll and an orbiting scroll that are designed and arranged in way that they perform an orbiting movement in relation to each other in order to compress a refrigerant. Such a design is, as such, known in the state of the art. The shaft 3 is held by a bearing 5 in a rotatable manner. To hinder an axial movement of the shaft 3 relative to the housing 2, a retainer ring 6 is attached onto the shaft 3. On an opposing side, that shaft 3 is held in a rotatable manner in a pot-shaped retainer 20. The attachment of the retainer ring 6 on the shaft 3 is realised by a shrink-fit attachment technique, resulting in a strong frictiontype connection. The shrink-fit assembly is performed in a way that the retainer ring 6 is brought to an elevated temperature and slid onto the shaft 3 (shaft unheated). After cooling, the retainer ring 6 is fixedly attached to the shaft 3.

[0048] In the presently shown embodiment, the retainer ring 6 is designed and arranged as a simple circular ring. A balancing of mass is presently performed by an appropriate construction of the compressor unit 4.

[0049] Fig. 2 shows this component assembly 19 in an enlarged cross-sectional view.

[0050] During assembly of the retainer ring 6 on the shaft 3, various problems can occur. As an example, the retainer ring 6 might be found to be somewhat displaced (relative to its intended position) after shrinking of the retainer ring 6 (due to thermal cooling) has been completed. In practical cases it has been found to be very complicated or even to be essentially impossible to remove the retainer ring 6 from the shaft 3 without damaging the shaft 3 (and possibly other parts as well). This is due to the very strong frictional force between the two parts 3, 6 after such a shrink-fit assembly.

[0051] Since the retainer ring 6 has an almost insignificant cost relative to the cost of the shaft 3 with its attached parts (in particular the compressor unit 4), it is essential not to damage the shaft 3 (and other parts), while the destruction of the retainer ring 6 may be easily tolerated.

[0052] Hence the proposal is present in the state-of-the-art to simply cut open or split open the retainer ring 6 using an appropriate tool (chisel, saw, milling head or the like). However, this approach is very problematic since the shaft 3 may be easily damaged by the respectively used tool.

[0053] To avoid such a problematic damage of the shaft 3, according to the present disclosure, the formation of at least one groove 7 or recess 7 is suggested. A possible design for such a groove 7 is shown in Fig. 3, where a possible embodiment of the retainer ring 6 (for example to be used in the context of the compressor 1 according to Figs. 1 and 2) is depicted in a schematic perspective view.

[0054] The groove 7 is arranged on the radially inner surface 8 of the retainer ring 6. Therefore, the normally cylindrically shaped inner surface 8 is interrupted by the groove 7.

[0055] In the presently shown embodiment of a retainer ring 6, the groove 7 has an essentially rectangular cross-section when seen in a cross-sectional view, where the cross-sectional plane is normal to the axial direction of the retainer ring 6 (see Fig. 6a). However, it is to be noted that different shapes may be used for the groove 7, like a triangular-shaped groove 9 (see Fig. 6b) or a semi- circular-shaped groove 10 (as it is shown in Fig. 6c).

[0056] Further, in the presently shown embodiment, the axial extent of the retainer ring 6 is shortened in the vicinity of the groove 7, as compared to the remainder of the retainer ring 6. In other words, near the groove 7, an axial notch 11 (axially oriented notch 11 ) is provided in the retainer ring 6. This way, a remaining closing web 12 is formed that shows a smaller dimension with respect to the radial direction, as well as with respect to the axial direction of the retainer ring 6. Nevertheless, the closing web 12 is dimensioned in a way that the retainer ring 6 does not break open unintentionally, at least not under usual circumstances. If the retainer ring 6 has to be removed from the shaft 3 for whatever reason, a milling head or a similar tool can be advanced into the outside of retainer ring 6. This way, the closing web 12 can be easily cut open by material removal techniques. Thanks to the groove 12, there is some safety volume between the inner surface of the closing web 12 and the outer surface of shaft 3, so that a damage of the outside surface of shaft 3 can be easily avoided. As an example, if the groove 7 has a depth of 1 mm, a guiding precision of the cutting tool of 0.5 mm (which is easily achievable) is more than sufficient to avoid an unintended scratching of the outer surface of shaft 3.

[0057] Once the closing web 12 is cut open, the remaining structure of the retainer ring 6 can be bent open and easily pulled off in an axial direction.

[0058] To further facilitate the removal process of retainer ring 6, it is possible to modify the design of the retainer ring 6. Two possible modifications are shown in Figs. 4 and 5, while it is obvious to a person skilled in the art that an essentially indefinite number of modifications can be realised.

[0059] Fig. 4 shows a first modification of the retainer ring 6 according to Fig. 3. Fig. 4 is a schematic top view onto the retainer ring 13. In this modification, the retainer ring 13 has two grooves 7 that are placed essentially opposite to each other, i.e. at an angle of essentially 180°. While it is still possible to cut open only one closing web 12 that is neighbouring one of the grooves 7, is also possible to cut open both closing webs 12. Then, the remaining half shells of the retainer ring 13 may be easily removed from the shaft 3. In effect, those half shells usually fall down on their own under the influence of gravity.

[0060] Fig. 5 shows a second possible modification of a retainer ring 14, again in a schematic top view. Here, the two grooves 7 are arranged at an angle of presently approximately 150°. It is to be noted that even at this angle, the cutting process of both closing webs 12 adjacent to the grooves 7 will result in an easy removability of the two remaining parts of the retainer ring 14.

[0061] Figs. 7 and 8 show that the same basic idea of a recess 7 and an adjacent closing web 12 (where the closing web 12 has a decreased radial extent with respect to the other parts of the ring-like member 18) can be applied to different members as well, namely to counterweight members 15, 16. Figs. 7 and 8 show two possible embodiments of counterweights 15, 16 in schematic perspective views.

[0062] The respective counterweights 15, 16 show a cam 17 with a certain angular range on the outside of the respective ring-like member 18 of the respective counterweight 15, 16.

[0063] As it is well known in the prior art, such counterweight members 15, 16 may be used to compensate for some imbalanced masses of the shaft 3 and the sub-parts that are attached to the shaft 3.

[0064] Particular attention is directed to the presently shown design, where the axial extent of the ring-like member 18 is not shortened in the proximity of the groove 7 relative to the remaining parts of the ring-like member 18. In other words, presently no axial notch 11 is employed.

[0065] However, it is to be noted that even for counterweights 15, 16, an axial notch 11 might be used. Vice versa, it is also possible that a retainer ring 6 (see Figs. 3, 4, 5) does not show an axial notch 11 .

[0066] Counterweight 15 according to Fig. 7 shows a single groove 7. This design is similar to the design of retainer ring 6 of Fig. 3 that also comprises a single groove 7. Counterweight 16 according to Fig. 8, however, shows two grooves 7 that are arranged at an angle of presently approximately 150° relative to each other, similar to the design of the retainer ring 14 according to Fig. 5. Here, the size of the angle of presently 150° is obviously advantageous, since a cam 17 with a circumferential range of 180° is presently used. Nevertheless, the closing webs 12 in the vicinity of the groove 7 are arranged in a thin section of the ringlike member 18 of counterweight 16. Consequently, a cutting operation requires less material to be removed, thus improving the processing speed considerably (possibly reducing the wear of the tools used as well).

[0067] It is noted that identical reference numerals are used throughout the present disclosure for parts that are sufficiently similar in design and / or in function to justify the use of identical reference numerals, although the respective parts may not be identical. This is done for brevity and to improve the understandability of the description.

[0068] It is to be noted that a single one or a plurality of the features of one, several or all of the presently disclosed detailed embodiments may be used in combination with the generic description of the present disclosure.

[0069] Reference list:

[0070] 1. compressor

[0071] 2. housing

[0072] 3. shaft

[0073] 4. compressor unit

[0074] 5. bearing

[0075] 6. retainer ring

[0076] 7. groove (rectangular)

[0077] 8. inner surface

[0078] 9. triangular groove

[0079] 10. semi-circular groove

Claims

CLAIMS1 . Component assembly (19), comprising a first part (3), and a second part (6, 13, 14, 15, 16), wherein the second part (6, 13, 14, 15, 16) encompasses the first part (3) at least partially, wherein the first part (3) and the second part (6, 13, 14, 15, 16) are connected to each other by a friction-type connection, characterised in that at least one of the first part (3) and the second part (6, 13, 14, 15, 16) comprises at least one recess (7) neighbouring the contact surface of the first part (3) and the second part (6, 13, 14, 15, 16).

2. Component assembly (19) according to claim 1 , characterised in that the at least one recess (7) constitutes a non-contacting area between the first part (3) and the second part (6, 13, 14, 15, 16).

3. Component assembly (19) according to claim 1 or 2, characterised in that the second part (6, 13, 14, 15, 16) fully encompasses the first part (3) in a circumferential way.

4. Component assembly (19) according to any of the preceding claims, characterised in that at least one of the first part (3) and the second part (6, 13, 14, 15, 16) are designed in an elongated way, preferably comprising an axially elongated design.

5. Component assembly (19) according to any of the preceding claims, in particular according to claim 3 or 4, characterised in that the frictiontype connection of the at least two parts acts in the axial direction.

6. Component assembly (19) according to any of the preceding claims, in particular according to claim 5, characterised in that the at least two parts are connected by a positive form lock connection in a radial and / or a tangential direction.

7. Component assembly (19) according to any of the preceding claims, in particular according to claim 3, 5 or 6, characterised in that the first part (3) comprises a rod-like section (3) or is essentially shaped as a rod (3) and / or characterised in that the second part (6, 13, 14, 15, 16) comprises a ring-like section (8, 18) and / or a cylinder barrel-like section or is essentially ring-like shaped (8) and / or cylinder barrel-like shaped.

8. Component assembly (19) according to any of the preceding claims, characterised in that at least one recess (7) is arranged in the second part (6, 13, 14, 15, 16), wherein preferably the majority, more preferably all recesses (7) are arranged in the second part (6, 13, 14, 15, 16).

9. Component assembly (19) according to any of the preceding claims, characterised in that the at least one recess (7) is arranged on a radially inner surface (8) of the second part (6, 13, 14, 15, 16).

10. Component assembly (19) according to any of the preceding claims, in particular according to claim 8 or 9, characterised in that at least two recesses (7), in particular at least two recesses (7) in the second part (6, 13, 14, 15, 16), are arranged at an angle of at least 90°, 100°, 110°, 120°, 130°, 135°, 140°, 150°, 160° or 170°, preferably at an angle of essentially 180°.

11. Component assembly (19) according to any of the preceding claims, characterised in that at least one recess (7) has a shape, taken from the group comprising V-shaped recesses, rectangular recesses (7), semi-circular recesses and rounded recesses.

12. Component assembly (19) according to any of the preceding claims, in particular according to any of claims 9 to 11 , characterised in that at least one, preferably a plurality, even more preferably all recesses (7)extend over essentially the axial extent of the second part (6, 13, 14, 15, 16).

13. Component assembly (19) according to any of the preceding claims, characterised in that the first part (3) and the second part (6, 13, 14, 15, 16) are assembled together via a shrink-fit or a press-fit connection.

14. Component assembly (19) according to any of the preceding claims, characterised in that the first part (3) is designed and arranged as a compressor shaft (3) or an electric motor shaft and / or characterised in that the second part (6, 13, 14, 15, 16) is designed and arranged as a retaining member (7), as a shaft stopper, as a rotor stopper and / or as a counterweight (15, 16).

15. Component assembly (19) according to any of the preceding claims, characterised in that the second part (6, 13, 14, 15, 16) has a shortened axial extent in the vicinity of at least one recess (7).

16. Electric motor and / or compressor device (1 ), characterised by at least one component assembly (19) according to any of the preceding claims.

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