The present invention relates to a refrigerant compressor comprising a hermetically sealed housing and a drive unit disposed in the interior of the housing, having a piston/cylinder unit for cyclical compression of a refrigerant, and an electric motor for drive of the piston/cylinder unit, wherein a damping apparatus for damping and limiting a deflection of the drive unit is provided in the interior of the housing, the damping apparatus comprising an inner element, which is connected with the drive unit, and an outer element, which surrounds the inner element, wherein a movement volume that is limited, at least in certain sections, by means of at least one wall element, is provided in the housing, in which movement volume the inner element and the outer element are disposed, wherein in a first state of the drive unit, at least the inner element can be moved in the movement volume, and wherein in a second, deflected state of the drive unit, the inner element is pressed against the at least one wall element, with interposition and elastic deformation of the outer element.
In the case of refrigerant compressors that comprise a hermetically sealed housing and a drive unit disposed in the interior of the housing, having a piston/cylinder unit for cyclical compression of a refrigerant, and an electric motor for drive of the piston/cylinder unit, relatively great forces occur, particularly during start and stop procedures, which forces lead to correspondingly relatively great deflections of the drive unit in the housing. In this regard, the drive unit is connected with the housing for vibration damping, usually by way of spring elements, which permit deflection of the drive unit. Particularly in the case of refrigerant compressors having a variable speed of rotation, the spring elements must be designed in relatively soft manner because of the low speeds of rotation that occur during operation, and this in turn results in greater deflections of the drive unit. A damping apparatus is provided in order to prevent contact of the drive unit with the housing in this connection.
This damping apparatus, according to the state of the art, has a cap that is disposed in the housing interior and rigidly connected with the housing—typically welded to the housing—which cap defines a movement volume. A spiral-shaped metal spring is attached in the cap. A metal bolt is disposed in a clear cross-section of the metal spring, which bolt is rigidly connected with the drive unit. The metal bolt can move within a certain range within the clear cross-section, without touching the metal spring. In normal operation, this allows a certain deflection of the drive unit. At very great deflections, as they particularly occur during start and stop procedures, the bolt touches the spring, causing it to be elastically deformed and pressed against the cap. This damps and limits the deflection of the drive unit.
A disadvantage in this regard is the relatively great noise development. The contact of metal on metal due to contacting of the spring by the bolt contributes to this. Furthermore, the sound is transferred very well to the cap, and from the cap to the housing. The noise generated in this way is subjectively perceived by the user as bothersome.
It is therefore the task of the invention to provide a refrigerant compressor that avoids the disadvantages mentioned above. In particular, the refrigerant compressor according to the invention is supposed to prevent or at least minimize disruptive noise development, as it preferentially occurs in start and stop procedures of refrigerant compressors having a variable speed of rotation.
It is the core of the invention to further improve the damping properties and, in this regard, to particularly prevent metallic noises, in that a damping element composed of a polymer material or of vulcanized rubber is provided. In this regard, a polymer material is understood to mean a material or plastic in accordance with DIN 7724, which comprises duroplastics, elastomers, thermoplastics and thermoplastic elastomers. From what has been said, it is evident that rubber, which can be produced both from a natural material and from a synthetic material, is a possible material for the damping element. The damping element, as an outer element, surrounds an inner element, which in turn is connected with the drive unit. The inner element can—but does not have to—be significantly more rigid than the outer element. Accordingly, it is provided, according to the invention, in the case of a refrigerant compressor comprising a hermetically sealed housing and a drive unit disposed in the interior of the housing, having a piston/cylinder unit for cyclical compression of a refrigerant, and an electric motor for drive of the piston/cylinder unit, wherein a damping apparatus for damping and limiting a deflection of the drive unit is provided in the interior of the housing, the damping apparatus comprising an inner element, which is connected with the drive unit, and an outer element, which surrounds the inner element, wherein a movement volume that is limited, at least in certain sections, by means of at least one wall element is provided in the housing, in which movement volume the inner element and the outer element are disposed, wherein in a first state of the drive unit, at least the inner element can be moved in the movement volume, and wherein in a second, deflected state of the drive unit, the inner element is pressed against the at least one wall element, with interposition and elastic deformation of the outer element, that the outer element is produced from a polymer material or vulcanized rubber. In this regard, it does not play any role whether the outer element is fixed in place on the at least one wall element or not.
Furthermore, the formation of the at least one wall element can also take place in the most varied manner. One possibility consists in using caps, something that can be particularly advantageous in terms of production technology and thereby with regard to costs. Therefore it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the at least one wall element is part of a cap disposed in the housing and rigidly connected with the latter. The use of caps is also advantageous in that this allows more flexible shaping of the housing, as long as it is ensured that at least one cap or multiple caps can be disposed in the housing and connected with it in essentially rigid manner. Preferably, the at least one cap is welded to the housing.
In order to make possible an embodiment variant that can be implemented in particularly simple manner, it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the outer element is fixed in place on the at least one wall element. In particular, the outer element can be fixed in place on the cap, in this connection. In this case, the inner element, in normal operation, can freely move in a region that is surrounded by the outer element, in accordance with the deflections of the drive unit. Only in the case of very great deflections does the inner element touch the outer element and deform it by pressing it against the wall element, particularly against the cap.
In order to achieve progressive damping, it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the outer element has an inner side that faces the inner element, which side delimits a clear cross-section of the outer element, and that the clear cross-section narrows, at least in certain sections, viewed parallel to a longitudinal axis of the outer element. The narrowing brings about the result that the inner element at first contacts only part of the outer element in the event of very great deflections of the drive unit, namely the part that has the smallest clear cross-section. Accordingly, only this part of the outer element is elastically deformed by the inner element at first. If this is not sufficient to limit the deflection of the drive unit, then in the event of increased deflection, contacting, by the inner element, of further parts of the outer element that delimit the clear cross-section comes about. The more parts are contacted, the greater the force required for further deformation of the outer element by the inner element, bringing about progressive damping. If no deflection of the drive unit is present, then the longitudinal axis of the outer element preferably lies parallel to a longitudinal axis of the inner element.
In order to allow particularly uniform and soft response of the progressive damping, it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the clear cross-section narrows, viewed parallel to the longitudinal axis and in the direction of a center of the outer element that lies on the longitudinal axis, and increases in size in the opposite direction. Preferably, the center of the outer element coincides with the center of the movement volume, so that the clear cross-section having the smallest size is disposed in the center of the movement volume. Furthermore, by means of the said shaping of the clear cross-section, particularly uniform damping behavior can be guaranteed, even if the longitudinal axis of the inner element does not run parallel to the longitudinal axis of the outer element. The latter can occur, for example, if rotation of the drive unit, preferably slight rotation, comes about during the course of its deflection.
In order to make particularly simple production of the outer element having the narrowing clear cross-section possible, it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the clear cross-section narrows in steps.
In order to make a stable intermediate position of the outer element between the inner element and the at least one wall element possible, and, at the same time, in order to be able to guarantee simple and stable fixation of the outer element on the at least one wall element, it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the outer element has an outer side that surrounds the inner element, in certain sections, and faces away from the inner element, which side is fixed in place, at least in certain sections, on the at least one wall element.
In a preferred embodiment of the refrigerant compressor according to the invention, it is provided that the outer element has an outer side that surrounds the inner element, in certain sections, and faces away from the inner element, which outer side contacts the at least one wall element in certain sections, in the first state of the drive unit, and is spaced apart from the at least one wall element, in certain sections. In that the outer side does not lie completely against the at least one wall element, damping in a starting phase can be configured to be relatively soft. This is because the spacing offers room for the outer element to be able to deform without contacting the at least one wall element in the case of a certain size of the deflections of the drive unit, at first, and this brings about relatively slight damping at first. Only in the case of greater deflections is the outer element pressed against the at least one wall element, and this brings about stronger damping.
In a preferred embodiment of the refrigerant compressor according to the invention, it is provided that the outer element has an outer side that surrounds the inner element in certain sections, and faces away from the inner element, which outer side overlaps with the at least one wall element, viewed parallel to the longitudinal axis, only in certain sections. In this way, particularly soft response behavior of the damping can be implemented in specific situations, if the inner element at first contacts only that part of the outer element that does not overlap with the at least one wall element, viewed parallel to the longitudinal axis, because this part of the outer element cannot be pressed against the wall. Of course, elastic deformation of this part of the outer element can come about nevertheless, bringing about slight damping of the corresponding deflection of the drive unit. Subsequently, in the case of even greater deflections, it can come about that then, also those parts of the outer element that overlap with the at least one wall element, viewed parallel to the longitudinal axis, are contacted by the inner element and elastically deformed by this element, leading to stronger damping and stronger limitation of the deflection of the drive unit. In total, once again a progressive damping characteristic can therefore be achieved.
In a preferred embodiment of the refrigerant compressor according to the invention, it is provided that the at least one wall element is part of a housing wall of the housing. In this case, no additional components, particularly no caps for forming the at least one wall element are necessary. Aside from the fundamental elegance of this solution, in this case the housing can also be kept particularly compact, since no additional caps have to be accommodated, something that would be advantageous for applications with constricted space conditions. It only needs to be ensured that the housing wall is suitably shaped in certain sections, in order to delimit the movement volume, at least in certain sections. Furthermore, this solution, of course, also offers a cost saving potential that cannot be underestimated, because of the reduced number of parts.
In a preferred embodiment of the refrigerant compressor according to the invention, it is provided that the outer element is fixed in place on the inner element. In this regard, the at least one wall element can be formed by the cap. Preferably, the at least one wall element is formed by the housing wall. Accordingly, an advantage of fixation of the outer element on the inner element lies in that this can be used universally in the most varied embodiment variants of the at least one wall element. Furthermore, that surface of the outer element that experiences elastic deformation for damping of the deflection of the drive unit and/or with which the outer element contacts the at least one wall element for damping of the deflection of the drive unit, can be configured to be particularly large, and this allows very strong and effective damping of the deflection of the drive unit.
Furthermore, a maximal contact surface between the two elements can always be guaranteed by means of attachment of the outer element on the inner element, and this also contributes to very strong and effective damping of the deflection of the drive unit. Accordingly, it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the outer element has an inner side that faces the inner element, which side is completely contacted by the inner element.
In order to improve the elastic behavior of the outer element in the sense of a more precise or softer response of the damping, it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the outer element has lamellae that contact the at least one wall element in the second state of the drive unit. In other words, at first elastic deformation of individual lamellae takes place at sufficiently great deflections of the drive unit, thereby making a soft response of the damping possible. Only at even greater deflections can elastic deformation of the remaining parts of the outer element, which do not have any lamellae, particularly of a basic body of the outer element, come about, and this brings about stronger damping. In total, once again, a progressive damping characteristic can be achieved. In this regard, it is preferably provided, for reinforcement of the progressive damping characteristic, that an envelope of the outer element is curved, at least in certain sections, so as to face away from the at least one wall element.
In order to make particularly simple production of the lamellae possible, it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the lamellae project from a basic body of the outer element in a normal line relative to the longitudinal axis.
In particular, embodiment variants are also possible, in which the inner element and the outer element are produced in one piece and thereby from the same material. Then, of course, the outer element and the inner element fundamentally demonstrate the same rigidity. Accordingly, it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the outer element and the inner element are structured in one piece.
In order to make particularly simple assembly of the refrigerant compressor, particularly of the damping apparatus, possible, and furthermore to ensure a long useful lifetime, particularly of the outer element, it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the outer element is structured in one piece.
In order to be able to transfer and damp the deflection of the drive unit particularly directly, it is provided, in a preferred embodiment of the refrigerant compressor according to the invention, that the inner element is produced from metal. At the same time, great stability and a long useful lifetime of the inner element is guaranteed in this way. Preferably, the inner element is structured as a bolt in this connection. Particularly preferably, the inner element is fixed in place in a block of the drive unit, which block functions as an additional mass of the drive unit, in order to lower the frequency of inherent oscillations of the drive unit.
The invention will now be explained in greater detail using exemplary embodiments. The drawings are meant as examples and are supposed to present the idea of the invention, but by no means to restrict it or to reproduce it in final manner.
In this regard, the figures show:
A refrigerant compressor 1 according to the state of the art is shown in the sectional view of
According to the state of the art, each damping apparatus 4 comprises a cap 9, which is rigidly connected with, preferably welded to, the housing 2 or a housing wall 8. A spiral-shaped metal spring 19 is attached in each cap 9. A bolt 29, preferably composed of metal and connected with the drive unit 3 in essentially rigid manner, is disposed in a clear cross-section of the respective metal spring 19.
Every movement or deflection of the drive unit 3 therefore brings about a corresponding deflection of the bolt 29. Preferably, the bolt 29 is fixed in place in a block 21 of the drive'unit 3, which block functions as an additional mass of the drive unit 3, in order to lower the frequency of natural oscillations of the drive unit 3.
The bolt 29 can move in a certain region within the clear cross-section without touching the metal spring 19. In normal operation, this makes a certain deflection of the drive unit 3 possible. At very great deflections, such as they occur, in particular, during start and stop procedures, the bolt 29 touches the metal spring 19, thereby causing the spring to be elastically deformed and pressed against the cap 9. This damps and limits the deflection of the drive unit 3, but at the same time results in undesirable noise development, with bothersome metallic noises.
For reduction of the noise development, a refrigerant compressor 1 according to the invention has damping apparatuses 4, which each comprise an outer element 6 composed of a polymer material or vulcanized natural rubber, particularly composed of rubber. The damping apparatus 4 of the refrigerant compressor 1 according to the invention furthermore has an inner element 5, which is connected with the drive apparatus 3 and surrounded by the damping element 6. The inner element 5 can have a greater rigidity than the damping element 6 and can be structured as a bolt or pin, for example, particularly composed of metal. Preferably, the inner element 5 is fixed in place in the block 21 of the drive unit 3.
The outer element 6 and the inner element 5 are disposed in a movement volume 7, which is delimited, at least in certain sections, by means of at least one wall element. In a first state of the drive unit 3, which corresponds to the normal operating state, at least the inner element 5 can be moved in the movement volume 7. In a second, deflected state of the drive unit 3, which corresponds to a relatively great deflection of the drive unit 3, the inner element 5 is also deflected to a correspondingly great extent, and presses against the at least one wall element, with interposition and elastic deformation of the outer element 6.
Independent of the material selection of the inner element 5, as well as of the at least one wall element, contact of metal on metal is prevented in the second state, in any case, by means of the material of the outer element 6. Furthermore, excellent damping of the deflection of the drive unit 3 is achieved by means of the elastically deforming material of the outer element 6. In total, contact of the drive unit 3 with the housing 2 can thereby be prevented, and bothersome noise development, particularly during start and stop procedures, can be drastically reduced.
A damping apparatus 4 of an embodiment of the refrigerant compressor 1 according to the invention is shown in the schematic sectional view of
The outer element 6 has an inner side 12 that faces the inner element 5 and delimits a clear cross-section 13 of the outer element 6. As can be seen in
For simple production, the narrowing of the clear cross-section 13 is carried out in steps. The smallest size of the clear cross-section 13 is disposed in a center 15 of the outer element 6 in the embodiment of
The embodiment of
The embodiments shown in
In the embodiments of
In the embodiment of
The outer element 6 has the clear cross-section 13 both in the region 25 and in the region 27. In this way, in certain situations, particularly if the longitudinal axis 28 of the inner element 5, as shown in
It should be noted that variants are also possible, in which the inner element 5 and the outer element 6 are produced in one piece and therefore from the same material (not shown). Of course, the outer element 6 and the inner element 5 then have fundamentally the same rigidity.
In the embodiment of
In the exemplary embodiment of
In the exemplary embodiment of
In the second state, progressive damping behavior can be achieved by means of the recesses 33 if at first, as shown in
1 refrigerant compressor
2 housing
3 drive unit
4 damping apparatus
5 inner element
6 outer element
7 movement volume
8 housing wall
9 cap
10 side wall of the cap
11 head wall of the cap
12 inner side of the outer element
13 clear cross-section of the outer element
14 longitudinal axis of the outer element
15 center of the outer element
16 outer side of the outer element
17 lamella
18 basic body of the outer element
19 metal spring
20 spring element
21 block of the drive unit
22 first end of the outer element
23 second end of the outer element
24 bent end region of the side wall
25 region of the outer element that overlaps the side wall
26 projection of the region of the outer element that overlaps the side wall
27 region of the outer element that does not overlap the side wall
28 longitudinal axis of the inner element
29 bolt
30 envelope of the outer element
31 outer wall of the outer element
32 inner wall of the outer element
33 recess of the outer element
34 deflection direction
35
a,
35
b section of the outer element
Number | Date | Country | Kind |
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GM50062/2015 | Apr 2015 | AT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2016/058397 | 4/15/2016 | WO | 00 |