Refrigerant compressor

Abstract

Refrigerant compressor with a hermetically sealed housing and a drive unit in the interior of the housing. At least one damping element is in the housing is connected to the drive unit. The damping element has three contact areas separated from each other by an edge, in which in a first deflected state of the drive unit a first contact area contacts a first inner surface area of the housing, wherein in a second deflected state a second contact area contacts a second inner surface area of the housing, but the first contact area does not contact the first inner surface area, wherein in a third deflected state of the drive unit a third contact area contacts a third inner surface area, but the first and second contact areas do not contact the first and second inner surface areas, respectively.

Claims

1. A refrigerant compressor comprising a hermetically sealed housing and a drive unit disposed in the interior of the housing, wherein at least one damping element for damping and limiting a deflection of the drive unit is provided in the interior of the housing, wherein the damping element is connected to the drive unit, wherein the damping element has at least one first a first contact area, a second contact area, and a third contact area, wherein in a basic state of the drive unit the at least one first contact area has a distance to a corresponding inner surface area of the housing, wherein in a first deflected state of the drive unit the first contact area is in contact with a corresponding first inner surface area of the housing, wherein the surface of the first inner surface area is parallel to the outer surface of this first area of the housing, wherein in a second deflected state of the drive unit the second contact area is in contact with a corresponding second inner surface area of the housing, but the first contact area is not in contact with the first inner surface area of the housing, whereas the surface of the second inner surface area is parallel to the outer surface of this second area of the housing, whereas the first direction of movement from the basic state to the first deflected state is perpendicular to the second direction of movement from the basic state to the second deflected state, and in that in a third deflected state of the drive unit the third contact area is in contact with a corresponding third inner surface area of the housing, but the first contact area is not in contact with the first inner surface area and the second contact area is not in contact with the second inner surface area, whereas the surface of the third inner surface area is parallel to the outer surface of this third area of the housing, whereas the third direction of movement from the basic state to the third deflected state is perpendicular to the second direction of movement from the basic state to the second deflected state and to the first direction of movement from the basic state to the first deflected state, and in that first contact area, second contact area and third contact area are separated from each other by at least one edge.

2. The refrigerant compressor according to claim 1, wherein the surface form of the first contact area of the damping element corresponds to the surface form of the first inner surface area of the housing, and/or the surface form of the second contact area of the damping element corresponds to the surface form of the second inner surface area of the housing, and/or the surface form of the third contact area of the damping element corresponds to the surface form of the third inner surface area of the housing.

3. The refrigerant compressor according to claim 1, wherein at least two contact areas of the damping element are planar and oriented perpendicular to each other.

4. The refrigerant compressor according to claim 3, wherein the third contact area of the damping element is planar and oriented perpendicular to the other two contact areas.

5. The refrigerant compressor according to claim 4, wherein the first, second, and third inner surface areas of the housing are planar and oriented perpendicular to each other.

6. The refrigerant compressor according to claim 3, wherein the protruding part of the drive unit has at least two planar surface areas which are covered by the damping element, which are oriented perpendicular to each other and which are oriented parallel to at least two planar contact areas of the damping element.

7. The refrigerant compressor according to claim 1, wherein the damping element is injection molded to a part of the drive unit.

8. The refrigerant compressor according to claim 1, wherein in a fourth deflected state of the drive unit a fourth contact area is in contact with a corresponding fourth inner surface area of the housing, whereas the surface of the fourth inner surface area is parallel to the outer surface of this fourth area of the housing, whereas the fourth direction of movement from the basic state to the fourth deflected state is antiparallel to the direction of movement from the basic state to the second deflected state.

9. The refrigerant compressor according to claim 8, wherein there are two damping elements, and whereas the directions of movement from the basic state to the third deflected state are antiparallel.

10. The refrigerant compressor according to claim 1, wherein there is a first and a second damping element, whereas the first direction of movement from the basic state to the first deflected state and the third direction of movement from the basic state to the third deflected state is the same for both damping elements, and the directions of movement from the basic state to the second deflected state are antiparallel.

11. The refrigerant compressor according to claim 10, wherein there are a third and a fourth damping element, whereas the first direction of movement from the basic state to the first deflected state is the same for all four damping elements, whereas the direction of movement from the basic state to the second deflected state is antiparallel to each other and whereas the direction of movement from the basic state to the third deflected state is antiparallel to the first and second damping element.

12. The refrigerant compressor according to claim 1, wherein in the basic state of the drive unit the first contact area has the first distance to the corresponding first inner surface area of the housing, the second contact area has a second distance to the corresponding second inner surface area of the housing and the third contact area has a third distance to the corresponding third inner surface area of the housing, and in that one of these distances is different from another of these distances.

13. The refrigerant compressor according to claim 1, wherein there is a first thickness of the damping element measured at the first contact area, a second thickness of the damping element measured at the second contact area and a third thickness of the damping element measured at the third contact area, and in that one of these thicknesses is different from another of these thicknesses.

14. The refrigerant compressor according to claim 1, wherein for the at least one damping element the dimensions of the first, second, and third inner surface areas of the housing are dimensioned so that until a certain partly deflected state of the drive unit the drive unit can move without contacting the first, second, and third inner surface areas.

15. The refrigerant compressor according to claim 3, wherein the protruding part of the drive unit has three planar surface areas which are covered by the damping element, which are oriented perpendicular to each other and which are oriented parallel to three planar contact areas of the damping element.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) 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.

(2) In this regard, the figures show:

(3) FIG. 1 a first refrigerant compressor according to the invention, seen from a first direction, with two bracket-formed damping elements,

(4) FIG. 2 the refrigerant compressor of FIG. 1, seen from a second direction,

(5) FIG. 3 the refrigerant compressor of FIG. 1, top part of housing removed, with two bracket-formed damping elements,

(6) FIG. 4 the refrigerant compressor of FIG. 3, seen from the other side,

(7) FIG. 5 a second refrigerant compressor according to the invention, housing removed, with four cap-formed damping elements,

(8) FIG. 6 a view of a longitudinal sectional through the upper portion of the refrigerant compressor of FIG. 5, with housing,

(9) FIG. 7 a view of a lateral section through the upper portion of the refrigerant compressor of FIG. 5, with housing,

(10) FIG. 8 a perspective view of FIG. 7,

(11) FIG. 9 a perspective view of another lateral section through the upper portion of the refrigerant compressor of FIG. 5, the section in front of two cap-formed damping elements,

(12) FIG. 10 a schematic sectional view of one damping element and the surrounding housing,

(13) FIG. 11 four views of a lateral section through the upper portion of the refrigerant compressor of FIG. 5, for different deflected states,

(14) FIG. 12 the view of FIG. 7, whereas an angle between the damping element and the housing is marked,

(15) FIG. 13-17 a view of a longitudinal section through the upper portion of the refrigerant compressor of FIG. 5, for different deflected states.

WAYS FOR IMPLEMENTATION OF THE INVENTION

(16) A first embodiment of a refrigerant compressor according to the invention is shown in FIG. 1-4. The refrigerant compressor has a hermetically sealed housing 5, as well as a drive unit 6 disposed in the interior of the housing 5, having a piston/cylinder unit 9 for cyclical compression of a refrigerant, and an electric motor 10 for drive of the piston/cylinder unit 9. The housing 5, also called shell, basically has two parts: a bottom part 15 which faces downward when the compressor is in use, and a top part 16 which faces upward when the compressor is in use. The top part 16 is a cover which is welded to the bottom part 15. The bottom part 15 mainly encloses the electric motor 10 and acts as an oil sump, the top part mainly encloses the piston-cylinder unit 9.

(17) The drive unit 6 is connected to the bottom part 15 of the housing 5 by means of spring elements, not shown, for vibration damping, so that deflections of the drive unit 6 can come about, particularly during start and stop procedures.

(18) Two bracket-formed damping elements 8a,b are provided on the drive unit 6, namely on the upper side of block 19 which, beside other functions, acts as the cylinder housing. Damping elements 8a,b prevent the drive unit 6 from making contact with the top part 16 of the housing 5. Every movement or deflection of the drive unit 6 brings about a corresponding deflection of the damping elements 8a,b. The damping element 8a,b can move in a certain extent without touching the top part 16 housing 5. In normal operation, this makes a certain deflection of the drive unit 6 possible. At very big deflections, such as they occur, in particular, during start and stop procedures of the compressor, the damping element 8a,b touches the housing 5, thereby causing the damping element 8a,b to be elastically deformed and pressed against the housing 5. This damps and limits the deflection of the drive unit 6, and at the same time does not result in undesirable noise development.

(19) For easier reference the following directions and orthogonal axes are defined: a first direction of movement is along the positive z-axis, the z-axis running vertical in FIG. 1-8, parallel to the crankshaft of the drive unit 6, the positive z-axis pointing to the top, a second direction of movement is along the positive y-axis, the y-axis running horizontal in FIG. 1-8, perpendicular to the cylinder axis, a third direction of movement is along the positive x-axis, the x-axis running horizontal in FIG. 1-8, parallel to the cylinder axis or piston rod 22, the positive x-axis pointing to the left in FIGS. 3 and 4, a fourth direction of movement is along the negative y-axis, a fifth direction of movement is along the negative x-axis, a sixth direction of movement is along the negative z-axis.

(20) Damping element 8a is mounted surrounding partially block 19 at the cylinder housing. So damping element 8a is situated nearer to the side of the compressor where the cylinder cover 21 and/or the valve plate is situated. Damping element 8b is situated nearer to the opposite side of the compressor. Both damping elements 8a,b have the form of a bracket and are symmetric to a plane defined by the cylinder axis or piston axis (=x-axis) and z-axis. Both lateral ends (parallel to the y-axis) of the damping elements 8a,b each form three contact areas 1,2,3 or 1,3,4.

(21) Referring to FIG. 3 and damping element 8a, this damping element 8a features one first contact area 1 on the top which itself features several bumps. This first contact area 1 is intended to limit movement of the drive unit 6 along the positive z-axis by contacting the inside of bulge 18a on its top. Damping element 8a on its near end in FIG. 3 features one second contact area 2, here in the form of an even surface, facing towards the positive y-axis. This second contact area 2 is intended to limit movement of the drive unit 6 along the positive y-axis by contacting the inside of bulge 18a on its respective side wall. Damping element 8a on its near end features one third contact area 3, here in the form of an even surface, facing towards the positive x-axis. This third contact area 3 is intended to limit movement of the drive unit 6 along the positive x-axis by contacting the inside of bulge 18a on its respective side wall.

(22) Damping element 8a on its far end in FIG. 3 features one fourth contact area 4, here in the form of an even surface, facing towards the negative y-axis. This fourth contact area 4 is intended to limit movement of the drive unit 6 along the negative y-axis by contacting the inside of bulge 18a on its respective side wall. This fourth contact area 4 is symmetric to the second contact area 2, with relation to a vertical symmetry plane through the axis of the cylinder. Damping element 8a on its far end features one third contact area 3, here in the form of an even surface, facing towards the positive x-axis. This third contact area 3 is intended to limit movement of the drive unit 6 along the positive x-axis by contacting the inside of bulge 18a on its respective side wall.

(23) So damping element 8a is able to limit movement of the drive unit 6 in the positive z-, y- and x-direction as well as in negative y-direction.

(24) Referring to FIG. 3 and damping element 8b, this damping element 8b features two first contact areas 1 on the top, one on each lateral end of damping element 8b. Each contact area 1 can feature several bumps, like here two bumps. These first contact areas 1 are intended to limit movement of the drive unit 6 along the positive z-axis by contacting the inside of bulge 18b on its top. Damping element 8b on its near end in FIG. 3 features one second contact area 2, here in the form of an even surface, facing towards the positive y-axis. This second contact area 2 is intended to limit movement of the drive unit 6 along the positive y-axis by contacting the inside of bulge 18b on its respective side wall. Damping element 8b on its near end features one third contact area 3, here in the form of an even surface, facing towards the negative x-axis. This third contact area 3 is intended to limit movement of the drive unit 6 along the negative x-axis by contacting the inside of bulge 18b on its respective side wall.

(25) Damping element 8b on its far end in FIG. 3 features one fourth contact area 4, here in the form of an even surface, facing towards the negative y-axis. This fourth contact area 4 is intended to limit movement of the drive unit 6 along the negative y-axis by contacting the inside of bulge 18b on its respective side wall. This fourth contact area 4 is symmetric to the second contact area 2, with relation to a vertical symmetry plane through the axis of the cylinder. Damping element 8b on its far end features one third contact area 3, here in the form of an even surface, facing towards the negative x-axis. This third contact area 3 is intended to limit movement of the drive unit 6 along the negative x-axis by contacting the inside of bulge 18b on its respective side wall.

(26) So damping element 8b is able to limit movement of the drive unit 6 in the positive z- and y-direction as well as in negative x- and y-direction. The third contact areas 3 on the far and near end here form in fact one common plane surface.

(27) Both damping elements 8a,b together limit movement of the drive unit 6 in the positive z-direction, in positive and negative y-direction as well as in in positive and negative x-direction. Damping elements 8a,b are not able to limit movement of the drive unit 6 in negative z-direction.

(28) The top part 16 of a housing 5 generally has a continuous convex form which means that, in any cross section, the curve of the housing wall is continuously differentiable, there is no step or bend. Now the top part 16 according to the invention has one bulge 18a and two bulges 18b. Each bulge 18a,b has three surfaces which are oriented orthogonally to each other. Bulge 18a has two planar surfaces which are orthogonal to the y-axis and one planar surface which is orthogonal to the x-axis. The surface which is orthogonal to the z-axis is slightly curved (smaller than 20°, favourably smaller than 10°) so that in the region where the damping element 8a touches the bulge 18a the surface is almost plane. First contact area 1 of bulge 18a can follow the curved surface form of bulge 18a. All bulges 18b have one planar surface which is orthogonal to the z-axis, one planar surface which is orthogonal to the y-axis and one planar surface which is orthogonal to the x-axis. So bulge 18a covers the whole length of damping element 8a. Damping element 8b is limited by two bulges 18b which are separated from another by another area of top part 16.

(29) A second embodiment of a refrigerant compressor according to the invention is shown in FIG. 5-9. The refrigerant compressor again has a hermetically sealed housing 5, as well as a drive unit 6 disposed in the interior of the housing 5, having a piston/cylinder unit 9 for cyclical compression of a refrigerant, and an electric motor 10 for drive of the piston/cylinder unit 9. From the housing 5 only the top part 16 is shown which faces upward when the compressor is in use. The bottom part 15 which faces downward when the compressor is in use, is not shown. Again, the top part 16 is a cover which is welded to the bottom part 15. The bottom part 15 mainly encloses the electric motor 10, the top part mainly encloses the piston-cylinder unit 9. Again, the drive unit 6 is connected with the bottom part 15 of the housing 5 by means of spring elements, for vibration damping, so that deflections of the drive unit 6 can come about, particularly during start and stop procedures.

(30) Four cap-formed damping elements 7a,b,c,d are provided on the drive unit 6, namely on the upper side of block 19 which, beside other functions, acts as the cylinder housing. Damping elements 7a,b,c,d prevent the drive unit 6 from making contact with the top part 16 of the housing 5. Every movement or deflection of the drive unit 6 brings about a corresponding deflection of the damping elements 7a,b,c,d. The damping element 7a,b,c,d can move in a certain extent without touching the top part 16 of housing 5. In normal operation, this makes a certain deflection of the drive unit 6 possible. At very great deflections, such as they occur, in particular, during start and stop procedures or during transport, e.g. the vehicle containing the compressor is moving, climbing or descending a hill, thus causing an inclination of the compressor, the damping element 7a,b,c,d touches the top part 16 of the housing 5, thereby causing the damping element 7a,b,c,d to be elastically deformed and pressed against the housing 5. This damps and limits the deflection of the drive unit 6, and at the same time does not result in undesirable noise development.

(31) Damping elements 7a,b,c,d basically have the same form whereas damping element 7a is oriented symmetrical to damping element 7b and damping element 7c is oriented symmetrical to damping elements 7d, always with relation to a vertical symmetry plane through the axis of the cylinder and/or to the crankshaft. In this example the cylinder axis plane is not exactly the same as the crankshaft bearing plane, so damping elements 7a,b are symmetric to the cylinder axis plane and damping elements 7c,d are symmetric to the crankshaft bearing plane. In other examples the cylinder axis plane may be the same as the crankshaft bearing plane.

(32) For easier reference the same directions and orthogonal axes as in FIG. 1-4 are used.

(33) Damping elements 7a,b are mounted surrounding a protruding part 20 of block 19 protruding from the cylinder housing. So damping elements 7a,b are situated nearer to the side of the compressor where the cylinder cover 21 and/or the valve plate is situated. Damping elements 7c,d are situated nearer to the opposite side of the compressor. All damping elements 7a,b,c,d form three contact areas 1-3 which are in use. Each contact area 1-3 contains, here is, an even surface and the three surfaces are oriented orthogonally to each other. In fact every damping element 7a,b,c,d forms four contact areas including two third contact areas 3, however, from the two third contact areas acting in direction of the x-axis only one contact area is in use.

(34) Referring to FIG. 5 and damping element 7a, this damping element 8a features one first contact area 1 on the top. This first contact area 1 here has the form of an even surface and is intended to limit movement of the drive unit 6 along the positive z-axis by contacting the inside of top part 16 of the housing 5 on its top. The top part 16 of the bulge 17a for this reason has been made parallel to the axis of the cylinder. Damping element 7a features one second contact area 2, here in the form of an even surface, facing towards the positive y-axis. This second contact area 2 is intended to limit movement of the drive unit 6 along the positive y-axis by contacting the inside of bulge 17a on its respective side wall. Damping element 7a features one third contact area 3, here in the form of an even surface, facing towards the positive x-axis. This third contact area 3 is intended to limit movement of the drive unit 6 along the positive x-axis by contacting the inside of bulge 17a on its respective side wall.

(35) Damping element 7b features one first contact area 1 on the top. This first contact area 1, here in the form of an even surface, is intended to limit movement of the drive unit 6 along the positive z-axis by contacting the inside of top part 16 of the housing 5 on its top. The top part 16 adjacent to the corresponding bulge 17a for this reason has been made parallel to the axis of the cylinder. Damping element 7b features one second contact area 2, here in the form of an even surface, facing towards the negative y-axis. This second contact area 2 is intended to limit movement of the drive unit 6 along the negative y-axis by contacting the inside of corresponding bulge 17a on its respective side wall. Damping element 7b features one third contact area 3, here in the form of an even surface, facing towards the positive x-axis. This third contact area 3 is intended to limit movement of the drive unit 6 along the positive x-axis by contacting the inside of corresponding bulge 17a on its respective side wall.

(36) Damping element 7c features one first contact area 1 on the top. This first contact area 1, here in the form of an even surface, is intended to limit movement of the drive unit 6 along the positive z-axis by contacting the inside of bulge 17b on its top. Damping element 7c features one second contact area 2, here in the form of an even surface, facing towards the positive y-axis. This second contact area 2 is intended to limit movement of the drive unit 6 along the positive y-axis by contacting the inside of corresponding bulge 17b on its respective side wall. Damping element 7c features one third contact area 3, here in the form of an even surface, facing towards the negative x-axis. This third contact area 3 is intended to limit movement of the drive unit 6 along the negative x-axis by contacting the inside of corresponding bulge 17b on its respective side wall.

(37) Damping element 7d features one first contact area 1 on the top. This first contact area 1, here in the form of an even surface, is intended to limit movement of the drive unit 6 along the positive z-axis by contacting the inside of bulge 17b on its top. Damping element 7d features one second contact area 2, here in the form of an even surface, facing towards the negative y-axis. This second contact area 2 is intended to limit movement of the drive unit 6 along the negative y-axis by contacting the inside of corresponding bulge 17b on its respective side wall. Damping element 7d features one third contact area 3, here in the form of an even surface, facing towards the negative x-axis. This third contact area 3 is intended to limit movement of the drive unit 6 along the negative x-axis by contacting the inside of corresponding bulge 17b on its respective side wall.

(38) All four damping elements 7a,b,c,d together limit movement of the drive unit 6 in the positive z-direction, in positive and negative y-direction as well as in in positive and negative x-direction. Damping elements 7a,b,c,d are not able to limit movement of the drive unit 6 in negative z-direction.

(39) The top part 16 according to this second embodiment of the invention has one bulge 17a for damping elements 7a,b and two bulges 17b, one for damping element 7c and one for damping element 7d. Each bulge 17b has three surfaces which are oriented orthogonally to each other. Bulge 17a has two surfaces 12,13 which are oriented orthogonally to each other, the first inner surface area 11 is curved. All bulges 17b have one plane surface which is orthogonal to the z-axis, one plane surface which is orthogonal to the y-axis and one plane surface which is orthogonal to the x-axis. Bulge 17a has one plane surface which is orthogonal to the y-axis and one plane surface which is orthogonal to the x-axis. The surface which is orthogonal to the z-axis is slightly curved (smaller than 20°, favourably smaller than 10°) so that in the limited region where the damping elements 7a,b touch the bulge 17a the surface is almost plane. Accordingly, the first inner surface areas 11 still realize a defined stop for the plane first contact areas 1 of damping elements 7a,b.

(40) The housing 5 has a wall which wall is deformed so that the wall thickness basically stays the same and the deformed inside and outside surface in this area is still basically parallel to each other. Of course, due to the deformation the thickness, especially in areas with a high curvature, may be reduced, but this is still understood as the wall thickness basically staying the same before and after deformation according to the invention.

(41) FIG. 6 shows a view of a longitudinal section through the upper portion of the refrigerant compressor of FIG. 5, this time with top part 16 of the housing 5. The drive unit 6 is in the basic position, the damping elements 7a,c are not deflected. In this sectional view one can see that damping element 7a completely encloses protruding part 20. The same applies for damping element 7b. Damping element 7c completely encloses second protruding part 23 of the drive unit 6. The same applies for damping element 7d. The thickness of the damping element 7a,c under first contact area 1 is bigger than the thickness of the damping element under third contact area 3.

(42) When the thickness of the damping elements 7a-d under first contact area 1 is bigger than for the other contact areas 2,3 this generally can enhance the stiffness of this central part of the damping element and this can help to avoid an unintended slip-off of the damping element from the protruding part 20,23 if the damping element is snap-fit to the protruding part 20,23. Basically, the thickness of the damping elements 7a-d,8a,b can be chosen freely, keeping a minimum amount of material that will avoid cracking or failure of the damping elements 7a-d,8a,b during the life of the compressor.

(43) The surface of the protruding parts 20,23 beneath the first contact area 1 is planar and thus parallel to the first contact area 1. The surface of the protruding parts 20,23 beneath the third contact area 3 is planar and thus parallel to the third contact area 3.

(44) The first inner surface area 11 of the housing 5, which corresponds to the first contact area 1 of the damping element 7a,c, is parallel to the first contact area 1. This is at least true for a first inner surface area 11 corresponding to 30-40% of the first contact area 1 on the right of damping element 7a in FIG. 6, and for a first inner surface area 11 corresponding to 50-60% on the left of damping element 7c in FIG. 6. The third inner surface area 13 of the housing 5, which corresponds to the third contact area 3 of the damping element 7a,c, is planar. This is at least true for a third inner surface area 13 corresponding to 20-30% of the third contact area 3 on the top of damping element 7a in FIG. 6, and for a third contact area 3 corresponding to 20-30% of the third contact area 3 on the top of damping element 7c in FIG. 6.

(45) The block 19 also comprises the crankshaft bearing 24.

(46) FIG. 7 shows a lateral section through the upper portion of the refrigerant compressor of FIG. 5. The drive unit 6 is in the basic position, the damping elements 7a,b are not deflected. In this sectional view one can see that damping element 7a,b each encloses protruding part 20 in an amount of approximately 250°, see dotted lines starting from an axis parallel to the x-axis in the middle of protruding part 20. The protruding part 20 here has a rectangular cross section, a major part of its longer side is—in a mathematical sense—fused with the upper part of the cylindrical cylinder housing. The longer side of protruding part 20 here is longer than the piston bore radius but not longer than the piston bore diameter.

(47) Seen in the positive z-direction, the protruding part 20 should preferably not be higher than the upper side of the block 19 at the cylinder housing, thus not increasing the total height of the compressor. It can be allowed to go slightly above this height if the curvature of the housing 5 allows so.

(48) The surface of the protruding parts 20 beneath the first contact area 1 is planar and thus parallel to the first contact area 1. The surface of the protruding parts 20 beneath the second contact area 2 is planar and thus parallel to the second contact area 2.

(49) The first inner surface area 11 of the housing 5, which corresponds to the first contact area 1 of the damping element 7a,b, is curved in this section. So the surface form of the of the first inner surface area 11 does not correspond to the form of the first contact area 1 of the damping element 7a,b. The second inner surface area 12 of the top part 16 of the housing 5, which corresponds to the second contact area 2 of the damping element 7a,b, is planar. This is at least true for a second inner surface area 12 corresponding to 10-20% of the second contact area 2 on the top of damping element 7a in FIG. 7.

(50) FIG. 8 shows a perspective view of FIG. 7, although the section is in a slightly different place.

(51) FIG. 9 shows a perspective view of another lateral section through the top part 16 of the housing 5 of the refrigerant compressor of FIG. 5. The section cuts the bulge 17b in front of the damping elements 7c,d so these are not cut. One can see their third contact areas 3. Arrows here indicate that the damping element 7c,d can also damp with the edge 14 between first and second contact area. The corresponding edge 25 between first 11 and second inner surface area 12 of the housing 5 has the same surface form as the edge 14 to bring about a good damping effect for a movement in the direction of the edge 14. This principle of similar edge forms can also be used for edges between first and third contact area 1,3 on the one hand and edges between first 11 and third inner surface area 13 of the housing 5 on the other hand; or for edges between second and third contact area 2,3 on the one hand and edges between second 12 and third inner surface area 13 of the housing 5 on the other hand.

(52) The drive unit 6 and its block 19 is in the basic position, the damping elements 7c,d are not deflected. In this view one can see that damping element 7c,d each encloses protruding part 23 in an amount of approximately 250°, as in FIG. 7. The protruding part 23 here has also a rectangular cross section, a major part of its longer side is—in a mathematical sense—fused with the upper part of the block 19. The dimensions of protruding part 23 are the same as of protruding part 20.

(53) In FIGS. 5 to 9 with regard to damping element 7a the first deflected state of the drive unit is reached (by movement in the positive z-direction) when first contact area 1 is in contact with the corresponding first inner surface 11 area of bulge 17a, whereas the second contact area 2 would not be in contact with second inner surface area 12 of bulge 17a and whereas the third contact area 3 would not be in contact with third inner surface area 13 of bulge 17a. The second deflected state is reached (by movement in the positive y-direction) when the second contact area 2 is in contact with second inner surface area 12 of bulge 17a, whereas the first contact area 1 would not be in contact with first inner surface area 11 of bulge 17a and whereas the third contact area 3 would not be in contact with third inner surface area 13 of bulge 17a. The third deflected state is reached (by movement in the positive x-direction) when the third contact area 3 is in contact with third inner surface area 13 of bulge 17a, whereas the first contact area 1 would not be in contact with first inner surface area 11 of bulge 17a and whereas the second contact area 2 would not be in contact with second inner surface area 12 of bulge 17a. First, second and third deflected state of the drive unit each is an extreme state which describes 100% deflection in x-, y- or z-direction. Such extreme state will hardly be reached during normal operation. During normal operation the drive unit will be in a superposition state of deflection with less than 100% deflection in all three directions.

(54) FIG. 10 shows a schematic sectional view of one edge 14 of a damping element 7a-d,8a,b and the surrounding housing 5. This shall illustrate another principle not shown in FIG. 1-9 in that for a certain damping element the dimensions of first, second and third inner surface area 11,12,13 of the housing 5 can be dimensioned so that until a certain partly deflected state of the drive unit 6 the drive unit can move, e.g. rotate along the curved arrows, without contacting first, second and third inner surface area 11,12,13. The edges 26 of the three inner surface areas 11,12,13 of the housing 5 (which inner surface areas basically can be contacted by the contact areas 1,2,3,4 of the damping element 7a-d,8a,b) with the adjacent inner surface of the housing are tangents on the surface of a sphere 27 defining the partly deflected state in which the damping element 7a-d,8a,b does not contact the housing 5. This principle could be applied to compressors with a high amount of displacement during start and stop operation.

(55) The damping elements 7a-d,8a,b are composed of a polymer material or vulcanized natural rubber, particularly composed of rubber. The damping elements 7a-d,8a,b can be injection molded or snapped on to the protruding parts 20, 23 of the drive unit 6.

(56) In FIGS. 6 to 9 the minimal distances between contact area 1-3 and corresponding inner surface area 11-13 of the top part 16 of the housing 5 do not show big differences between the different contact areas 1-3. However, one could make the minimal distance between first contact area 1 and first inner surface area 11 bigger than e.g. the minimal distance between second contact area 2 and second inner surface area 12 to allow for a bigger deflection in positive z-direction than in y-direction.

(57) A typical thickness of a metal sheet for forming top part 16 of the housing 5 is 2 to 4 mm. A typical diameter of the housing 5, measured along x- or y-axis, is 100 to 150 mm, or even more for bigger compressors.

(58) FIG. 11 shows four views of a lateral section through the upper portion of the refrigerant compressor of FIG. 5, for different deflected states. The section is parallel to the xy-plane and cuts the damping element 7c near the first contact area 1. The section shows only one half of the compressor, the other half for damping element 7d is basically symmetric to the depicted half. The block 19 forming the cylinder housing can be seen as well as the crankshaft. In the first picture the damping element 7c is in the basic state, the second and third contact area 2,3 have a defined distance (gap) to the inner surface areas 12,13 of the housing 5. In the second picture the damping element 7c has moved along the negative x-axis (along a fifth direction of movement as defined above under FIG. 1-4) to a deflected state where the third contact area 3 is in contact with the third inner surface area 13, whereas the second contact area 2 has not changed its distance to the inner surface area 12. In the third picture the damping element 7c has moved along the positive y-axis (along a second direction of movement as defined above under FIG. 1-4) to a deflected state where the second contact area 2 is in contact with the second inner surface area 12, whereas the third contact area 3 has not changed its distance to the inner surface area 13. In the fourth picture the damping element 7c has moved in a direction between the positive y-axis and the negative x-axis to a deflected state where the second contact area 2 is in contact with the second inner surface area 12 and the third contact area 3 is in contact with the inner surface area 13. Here the edge between second and third contact area 2,3 is in form-fit contact with the edge between the second and third inner surface area 12,13.

(59) FIG. 12 shows a simplified view of FIG. 7, where the angle between the damping element and the housing has been marked, that is the angle between the first contact area 1 and the first inner surface area 11. Although the first contact area 1 is plane the first inner surface area 11 is curved. The bulge 17a accommodating both damping elements 7a,b is rather wide in y-direction, so if the bulge would be made plane—in the sense that both first contact areas 1 for damping elements 7a,b would be part of one plane area—then the sound emission from this plane portion of metal sheet is higher than for a curved portion of metal sheet and thus could be too high. The angle between the tangent to the first inner surface area 11 and the first contact area 1 can be in the range of 5 to 20°, especially from 10 to 15°. This angle still allows for a determined stop of the damping element 7a,b in the positive z-direction.

(60) FIG. 13-17 each shows a view of a longitudinal section through the upper portion of the refrigerant compressor of FIG. 5, for different deflected states. FIG. 13-17 each shows a simplified view of FIG. 6. In FIG. 13 the drive unit 6 is in the basic state, the first and third contact area 1,3 of damping elements 7a,c have a defined distance (gap) to the inner surface areas 11,13 of the housing 5.

(61) In FIG. 14 the drive unit 6 has moved along the negative x-axis (along a fifth direction of movement as defined above under FIG. 1-4) to a deflected state where the third contact area 3 of damping element 7c is in contact with the third inner surface area 13, whereas the first contact area 1 has not changed its distance to the inner surface area 11.

(62) In FIG. 15 the drive unit 6 has moved along the positive x-axis (along a third direction of movement as defined above under FIG. 1-4) to a deflected state where the third contact area 3 of damping element 7a is in contact with the third inner surface area 13, whereas the first contact area 1 has not changed its distance to the inner surface area 11.

(63) In FIG. 16 the drive unit 6 has moved along the positive z-axis (along a first direction of movement as defined above under FIG. 1-4) to a deflected state where the first contact area 1 of damping element 7a and the first contact area 1 of damping element 7c is in contact with the first inner surface area 11, whereas the third contact area 3 of each damping element 7a,c has not changed its distance to the respective inner surface area 13.

(64) In FIG. 17 the drive unit 6 has moved in a direction between the positive z-axis and the negative x-axis to a deflected state where the first contact area 1 of damping element 7c is in contact with its first inner surface area 11, the first contact area 1 of damping element 7a is in contact with its first inner surface area 11 and the third contact area 3 of damping element 7c is in contact with the inner surface area 13. Here for damping element 7c the edge between first and third contact area 1,3 is in form-fit contact with the edge between the first and third inner surface area 11,13.

(65) In a combination of FIG. 11, last picture, and FIG. 17 the drive unit 6 has moved in a direction between the positive z-axis, the negative x-axis and the positive y-axis to a deflected state where the first contact area 1 of damping element 7c is in contact with its first inner surface area 11, the second contact area 2 of damping element 7a is in contact with its second inner surface area 12 and the third contact area 3 of damping element 7c is in contact with its inner surface area 13. Here for damping element 7c the corner between first, second and third contact area 1,2,3 is in form-fit contact with the corner between the first, second and third inner surface area 11,12,13.

LIST OF REFERENCE SYMBOLS

(66) 1 first contact area 2 second contact area 3 third contact area 4 fourth contact area 5 housing 6 drive unit 7a,b,c,d damping element 8a,b damping element 9 piston/cylinder unit 10 electric motor 11 first inner surface area of the housing 12 second inner surface area of the housing 13 third inner surface area of the housing 14 edge between first and second contact area 15 bottom part of the housing 5 16 top part of the housing 5 17a,b bulge 18a,b bulge 19 block 20 protruding part of the drive unit (of the block 19) 21 cylinder cover 22 piston rod 23 second protruding part of the drive unit (of the block 19) 24 crankshaft bearing 25 edge between first and second inner surface area of the housing 26 edge between inner surface areas 11,12,13 and adjacent inner surface of the housing 5 27 sphere