Patent Application
20250052455
The present disclosure relates to the subject matter disclosed in German application number 10 2023 121 141.2 of 8 Aug. 2023 and German application number 10 2023 122 080.2 of 17 Aug. 2023, which are incorporated herein by reference in their entirety and for all purposes.
The invention relates to a refrigerant compressor unit comprising a housing with a housing sleeve closed at the end, the housing sleeve comprising a compressor housing portion in which at least two cylinders, each with a piston arranged therein, and a drive chamber with drive units arranged therein and driven by a drive shaft are arranged, the housing sleeve comprising a motor compartment with an electric motor arranged therein and driving the drive shaft, a valve plate covering the cylinders being arranged on the housing sleeve and carrying a cylinder head on its side opposite the cylinders, in which cylinder head at least one inlet chamber and at least one outlet chamber are arranged.
Such refrigerant compressor units are known from the prior art.
The problem encountered with these, however, is to make them as light and compact as possible, but in such a way that they can be used as transcritical CO2 compressors in particular.
In a refrigerant compressor unit of the type described at the outset, provision is made in accordance with an embodiment of the invention that the cylinder head is manufactured from a cast material comprising iron, and that the housing sleeve, together with the compressor housing portion and a cylinder housing block, which accommodates the cylinders, and the motor housing portion form a single-piece part, in particular made of lightweight material.
The advantage according to an embodiment of the invention is that it makes it possible, on the one hand, to provide the cylinder head with the necessary stability, particularly when used as a transcritical CO2 compressor, and, on the other hand, to manufacture the other components of the refrigerant compressor unit from material with the lowest possible specific weight, particularly lightweight material.
In particular, such compressors can be used advantageously in refrigeration systems for any type of transportation application, for example vehicles for road and/or rail and/or aviation.
A wide variety of solutions are conceivable here with regard to the form of the cylinder head.
One solution is for the cylinder head to be manufactured from a cast material comprising an iron-carbon alloy.
Another option is for the cylinder head to be manufactured from cast steel.
Another alternative option is for the cylinder head to be manufactured from cast iron.
In the case of the manufacture of the cylinder head from cast iron, there are also further modifications.
One solution is for the cylinder head to be manufactured from cast iron with graphite.
In this case, the graphite could be present in the form of lamellar graphite.
For the stability of the cylinder head under high loads, however, it has proven to be particularly advantageous if the cylinder head is manufactured from cast iron with spheroidal graphite or vermicular graphite.
Furthermore, the lightweight material used for the housing sleeve has not been specified in greater detail.
An advantageous solution is that the housing sleeve with the compressor housing portion, the cylinder housing block and the motor housing portion is manufactured from light metal, in particular aluminum.
It is particularly advantageous if the housing sleeve with the compressor housing portion, the cylinder housing block and the motor housing portion is manufactured from an aluminum alloy with silicon, as this provides good stability despite its low specific weight.
In order to be able to advantageously mold the cylinders in the cylinder housing block into the housing sleeve in particular, it has proven to be expedient if the housing sleeve with the compressor housing portion, the cylinder housing block and the motor housing portion is manufactured as a cast part, in particular from cast light metal.
A particularly advantageous arrangement with regard to the possibility of providing an installation position with cylinders oriented transversely to the vertical direction is that the cylinders are arranged in succession in a row direction, with the row direction running in particular parallel to the drive shaft.
To save weight and in particular to improve the thermal expansion behavior, it has proven to be advantageous if, in addition to the cylinders, separate recesses are provided in the cylinder housing block.
No further details have been provided regarding the form of the housing sleeve.
An advantageous solution is for the housing sleeve to have mounting openings at the ends, which are closed by housing covers.
The mounting openings at the end therefore allow easy access for installing the drive units with the drive shaft in the drive chamber on the one hand and easy access for installing the electric motor in the motor compartment on the other.
No further details have been provided with regard to the housing covers either.
One advantageous solution is that the housing covers are also manufactured from light metal, in particular aluminum.
In order to make the housing as compact and space-saving as possible and thus also weight-saving, an advantageous solution is that the housing covers are curved in order to give them sufficient stability with the lowest possible weight.
In particular, it is provided that one of the housing covers has a concave curvature extending into the housing sleeve.
Furthermore, it is advantageously provided that one of the housing covers has a convex curvature curving away from the housing sleeve.
In this case, the convex curvature can be used to increase the space in the housing sleeve, in particular the motor compartment, required for the installation of components such as the electric motor.
In this case, for example, in particular one of the housing covers is provided with at least one contact insert for passing through electrical connections, so that the space required for this contact insert and the electrical connections can also be formed by the curvature of the housing cover itself.
In addition, it is expediently provided that one of the housing covers is provided with a refrigerant connection in order to easily supply refrigerant to the housing.
In particular, the connections in the housing covers make it possible not to arrange them in the housing sleeve and thus not to impair the structure of the housing sleeve and consequently also its stability through the connections.
With regard to the further form of the housing sleeve, it is advantageous if the housing sleeve is provided with an intermediate wall integrally molded thereon in one piece and separating the drive chamber from the motor compartment.
On the one hand, such an intermediate wall integrally formed in one piece on the housing sleeve stabilizes the housing sleeve in a simple manner and creates the possibility of stabilizing the housing sleeve additionally in a weight-saving manner by means of the shape of this intermediate wall, for example by means of struts extending away from it.
In this case, in particular, a bearing portion is provided in the intermediate wall for the drive shaft passing through it.
No further details have yet been provided regarding the form of the cylinder head.
One advantageous solution is for the cylinder head to have a high-pressure connection for refrigerant so that the cylinder head can be connected directly to the high-pressure line. This prevents the heat-sensitive lightweight material of the housing from coming into contact with the hot, high-pressure compressed refrigerant.
In an advantageous embodiment, it is further provided that the cylinder head has a connection for refrigerant at low pressure.
In order to be able to optimally cool the motor compartment, it is preferable that sucked-in refrigerant flows through the motor compartment, and in particular the electric motor, so that sufficient cooling of the electric motor can be easily realized.
Furthermore, the refrigerant flowing through the motor compartment is preferably fed through a channel to a passage opening in the valve plate to allow it to enter the inlet chamber in the cylinder head.
In particular, it is provided that the refrigerant enters an inlet chamber of the cylinder head after cooling the electric motor.
Preferably, the channel supplying the refrigerant to the valve plate is molded into the intermediate wall of the housing sleeve.
In order to additionally create the possibility of maintaining the drive chamber at the pressure of the refrigerant flowing through the motor compartment, it is preferable for the channel to be connected to a channel leading to the drive chamber.
In particular, in the case of a two-stage refrigerant compressor unit, it is provided that the cylinder housing block has at least one cylinder for compressing refrigerant from low pressure to medium pressure and at least one cylinder for compressing refrigerant from medium pressure to high pressure.
In the simplest case, the cylinder head can be formed in such a way that the cylinder head has an inlet chamber for refrigerant at low pressure, an outlet chamber for refrigerant at medium pressure, an inlet chamber for refrigerant at medium pressure and an outlet chamber for refrigerant at high pressure.
In this embodiment also in particular, the cylinders are arranged in succession in a row direction in order to be able to orient the cylinders also transversely to a vertical direction.
For safe operation of the refrigerant compressor unit in a refrigerant circuit, the cylinder head is provided with a pressure relief valve connected to the outlet chamber for refrigerant compressed to high pressure.
In order to avoid conditions with overpressure of the supplied refrigerant on the low-pressure side as well, for example during stoppage phases, it is expedient that the cylinder head is provided with a pressure relief valve connected to the inlet chamber.
To reduce the installation height of the refrigerant compressor unit according to the invention, it is expedient that the cylinder housing block is arranged in an operating position or installation position on the housing sleeve in such a way that the cylinders extend transversely to a vertical direction.
In particular, it is provided here that the pistons move in the cylinders in a direction of movement that is transverse to the vertical direction, in particular at an angle of between 70° and 110° to the vertical direction.
In order to further optimize the installation situation, it is provided that the housing is arranged in an operating position or installation position such that the cylinder housing block, the valve plate and the cylinder head are arranged relative to the housing sleeve in a direction transverse to a vertical direction on one side of the housing sleeve.
In order to obtain favorable lubrication in the drive chamber of the compressor housing portion, it is provided that a lubricant bath forming in this is arranged in the vertical direction below the cylinders and at a spacing therefrom, so that the pistons also move above the lubricant bath.
In order to achieve a sufficiently good distribution of the lubricant, a lubricant feed unit is provided in the compressor housing portion and receives lubricant from the motor compartment and feeds it to the lubricant bath in the compressor housing portion.
Furthermore, it is preferably provided that the housing is provided with at least two mounting lugs which permit mounting of the housing in such a way that the cylinder housing block, the valve plate and the cylinder head are arranged relative to the housing sleeve in the direction transverse to a vertical direction on one side of the housing sleeve.
In principle, the mounting lugs can be arranged on the housing covers.
However, it is advantageous if the mounting lugs are arranged on the housing sleeve.
Furthermore, it is preferable that mounting rails are arranged on the mounting lugs to allow mounting on a mounting surface.
The mounting surface can, for example, be an approximately horizontal mounting surface or also an approximately vertical mounting surface.
Alternatively or additionally, in a refrigerant compressor unit of the type described above, it is provided that the stator is mounted in the motor housing portion by means of support elements which are installed into the motor housing portion and which, on the one hand, bear against a stator receiving surface of the motor housing portion and, on the other hand, surround the stator installed into the support elements on its outer side, in particular over at least three quarters of a circumference thereof, and support it resiliently relative to the stator receiving surface.
The advantage of this solution is that the resilient support of the stator relative to the stator receiving surface makes it possible to compensate for variations in the diameter of the stator receiving surface of the motor housing portion manufactured from lightweight material and at the same time ensures that the stator is always centered in the motor housing portion, since the support elements surrounding the stator and resiliently supporting it relative to the stator receiving surface are each effective on opposite sides of the stator between the latter and the motor housing portion and thus keep the stator centered relative to the motor housing portion both in the event of thermally induced and pressure-induced diameter variations.
The advantage of this is that the gap between the stator and the rotor can be kept as small as possible, thus enabling the electric motor to achieve a high level of efficiency.
The resiliently effective support elements can be formed in a wide variety of ways. For example, the support elements can be thick elastic bands.
A particularly advantageous solution is for the support elements to have resilient bodies which are dimensioned such that they are in an elastically deformed state in all operating states of the motor housing portion occurring during operation of the refrigerant compressor, i.e., in no operating state do the resilient bodies enter the range of plastic deformation, which would result in the elastic properties of the resilient bodies changing.
In particular, it is advantageous for the support elements to be arranged running around the stator and to each support the stator on opposite sides of the rotor axis several times relative to the stator receiving surface of the motor housing portion in order to achieve a uniform resilient positioning of the stator acting on it from all sides.
Furthermore, it is preferable that the support elements have resilient bodies arranged at defined angular intervals about the rotor axis.
For example, this solution also enables the electric motor to be cooled by allowing refrigerant to flow between the stator receiving surface and the outer side of the stator and through the support elements parallel to the rotor axis.
In particular, the resilient bodies are positioned relative to each other on the stator receiving surface by a band material positioning them relative to each other and running around the stator.
A particularly simple realization of the resilient bodies is that they are molded into the band material.
A particularly favorable solution is that the band material is formed as a ring-like clasp with open ends, so that it can be easily deformed for mounting in the motor housing portion and thus inserted without producing shavings, in particular in a motor housing portion manufactured from light metal.
A particularly simple realization of the resilient bodies is that they have flank regions running at an acute angle to the outer side of the stator and/or to the stator receiving surface between foot regions and support regions, some of which bear against the outer side of the stator and the others against the stator receiving surface.
Such flank regions running at an angle to the outer side of the stator and/or to the stator receiving surface enable resilient movement of the support regions relative to the foot regions without the foot regions or support regions moving in a direction of rotation around the stator, as the resilient movement takes place primarily in the flank regions.
A particularly advantageous solution provides for the resilient bodies to be successively molded into a resilient band material, so that successive support regions bear against an outer side of the stator or against the stator mounting surface and successive foot regions bear against the stator receiving surface or the outer side of the stator, in other words, the support regions and the foot regions are arranged in succession in a direction of rotation around the stator and thus the resilient support of the stator relative to the stator receiving surface takes place substantially around the entire stator.
It has also proved advantageous if the resilient bodies are located between edge regions arranged circumferentially around the stator and the support regions are connected to the edge regions by means of flank regions running at an acute angle to the outer side of the stator and/or to the stator mounting surface.
This solution has an advantageous elastic support of the support regions relative to the edge regions by means of these flank regions, in particular in addition to the flank regions connecting the support regions to the foot regions, and in addition, such flank regions allow the stator to be pushed into the support elements already resting on the stator receiving surface due to their effect a lead-in chamfer, wherein the stator is pushed in parallel to the rotor axis of the electric motor.
In this solution, the support regions are preferably located on the outer side of the stator or the stator receiving surface on the one hand and the edge regions on the stator receiving surface or the outer side of the stator on the other hand.
In particular, the support elements formed in accordance with one or more of the features described above enable the stator and housing sleeve to be decoupled, wherein on the one hand the support elements can be mounted in the housing sleeve without producing shavings and then on the other hand the stator can be mounted without producing shavings, in particular by means of the flank regions formed as lead-in chamfers, by pushing it in and removed by pulling it out, wherein the stator deforms the resilient elements when it is pushed in.
In particular, if the support elements described above are not annularly closed elements, but surround the stator, although they have ends that can be positioned at a spacing from each other circumferentially, the support elements can be inserted easily and without damaging the housing sleeve by means of corresponding elastic deformation to reduce the outer contour.
This is particularly advantageous if the housing sleeve is formed from light metal, preferably aluminum, or cast aluminum.
With regard to the form of the support elements themselves, no further details have been provided in conjunction with the previous explanation of the solution according to the invention.
One advantageous solution is that the support elements are formed from a resilient material, in particular spring steel.
The stator can be pushed into or pulled out of the support elements without producing shavings, especially if the support elements are formed from resilient material.
Furthermore, no information has yet been provided on how the support elements are positioned in the motor housing portion.
An advantageous solution for achieving a defined relative position of the support elements is that support elements arranged in succession in the direction of the rotor axis are positioned at a distance from one another in the motor housing portion by means of a spacer element.
Preferably, the spacer element bears against the stator receiving surface of the motor housing portion in the same way as the support elements and holds the support elements at the distance specified by the length of the spacer element in the direction of the rotor axis.
In particular, the spacer element also bears against the stator receiving surface, surrounding the stator.
In order to be able to orient at least one of the support elements with respect to its position in the motor housing portion in a defined manner relative to the stator receiving surface, it is preferably provided that at least one of the support elements is positioned with respect to its position in the motor housing portion by a step adjoining the stator receiving surface, specifically in that the support element is positioned with at least one side in contact with the step.
In addition, it is expedient that the refrigerant compressor is configured for CO2 as refrigerant and thus a high pressure to be generated is above 80 bar and a medium pressure to be generated is above 40 bar, depending on the embodiment.
The above description of solutions according to the invention thus comprises in particular the various combinations of features defined by the following consecutively numbered embodiments:
1. A refrigerant compressor unit (10), comprising a housing (12) with a housing sleeve (16) closed at the end, the housing sleeve (16) comprising a compressor housing portion (26) in which there are arranged at least two cylinders (42, 44, 46), each with a piston (62, 64, 66) arranged therein, and a drive chamber (38) with drive units (92, 94, 96) arranged therein and driven by a drive shaft (70), wherein the housing sleeve (16) comprises a motor compartment (158) with an electric motor (170) arranged therein and driving the drive shaft (70), a valve plate (120) covering the cylinders (42, 44, 46) being arranged on the housing sleeve (16) and carrying a cylinder head (140) on its side opposite the cylinders (42, 44, 46), in which cylinder head at least one inlet chamber (142) and at least one outlet chamber (144) are arranged, wherein the cylinder head (140) is manufactured from a cast material comprising iron, and in that the housing sleeve (16), together with the compressor housing portion (26) and a cylinder housing block (40), which accommodates the cylinders (42, 44, 46), and the motor housing portion (28) form a single-piece part, in particular made of lightweight material.
2. A refrigerant compressor unit in accordance with embodiment 1, wherein the cylinder head (140) is manufactured from a cast material comprising an iron-carbon alloy.
3. A refrigerant compressor unit in accordance with embodiment 1 or 2, wherein the cylinder head (140) is manufactured from cast steel.
4. A refrigerant compressor unit in accordance with embodiment 1 or 2, wherein the cylinder head (140) is manufactured from cast iron.
5. A refrigerant compressor unit in accordance with embodiment 4, wherein the cylinder head (140) is manufactured from cast iron with graphite.
6. A refrigerant compressor unit in accordance with embodiment 5, wherein the cylinder head (140) is manufactured from cast iron with spheroidal graphite or vermicular graphite.
7. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the housing sleeve (16) with the compressor housing portion (26), the cylinder housing block (40) and the motor housing portion (28) is manufactured from light metal, in particular aluminum.
8. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the housing sleeve (16) with the compressor housing portion (26), the cylinder housing block (40) and the motor housing portion (28) is manufactured from a cast aluminum alloy with silicon.
9. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the housing sleeve (16) with the compressor housing portion (26), the cylinder housing block (40) and the motor housing portion (28) is manufactured as a cast part, in particular from cast light metal.
10. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the cylinders (42, 44, 45) are arranged in succession in the cylinder housing block (40) in a row direction (48), which in particular runs parallel to the drive shaft (70).
11. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the cylinder housing block (40) in addition to the cylinders (42, 44, 45) also has recesses (312, 314, 316, 318, 322) separate from the cylinders.
12. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the housing sleeve (16) has mounting openings (21, 23) at the ends, which are closed by housing covers (22, 24).
13. A refrigerant compressor unit in accordance with embodiment 12, wherein the housing covers (22, 24) are manufactured from light metal, in particular aluminum.
14. A refrigerant compressor unit in accordance with embodiment 12 or 13, wherein the housing covers (22, 24) are curved.
15. A refrigerant compressor unit in accordance with embodiments 12 to 14, wherein one of the housing covers (22) has a concave curvature (36) extending into the housing sleeve (16).
16. A refrigerant compressor unit in accordance with embodiments 12 to 15, wherein one of the housing covers (24) has a convex curvature (286) curving away from the housing sleeve (16).
17. A refrigerant compressor unit in accordance with embodiments 12 to 16, wherein one of the housing covers (24) is provided with at least one contact insert (252) for passing through electrical connections (264).
18. A refrigerant compressor unit in accordance with the preceding embodiments, wherein one of the housing covers (24) is provided with a refrigerant connection (278).
19. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the housing sleeve (16) is provided with an intermediate wall (156) integrally molded thereon in one piece and separating the drive chamber (38) from the motor compartment (158).
20. A refrigerant compressor unit in accordance with embodiment 19, wherein a bearing portion (164) is provided in the intermediate wall (156) for the drive shaft (17) passing through it.
21. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the cylinder head (140) has a high-pressure connection (304, 304′) for refrigerant.
22. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the cylinder head (140) has a connection (306′) for refrigerant at low pressure.
23. A refrigerant compressor unit in accordance with the preceding embodiments, wherein sucked-in refrigerant flows through the motor compartment (158).
24. A refrigerant compressor unit in accordance with embodiment 23, wherein the refrigerant flowing through the motor compartment (158) is fed through a channel (292) to a passage opening (294) in the valve plate (120).
25. A refrigerant compressor unit in accordance with embodiment 23 or 24, wherein the refrigerant enters an inlet chamber (142) of the cylinder head (140) after cooling the electric motor (170).
26. A refrigerant compressor unit in accordance with embodiment 24 or 25, wherein the channel (292) is molded into the intermediate wall (156).
27. A refrigerant compressor unit in accordance with embodiments 24 to 26, wherein the channel (292) is connected to a channel (296) leading to the drive chamber (28).
28. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the cylinder housing block (40) has at least one cylinder (42′, 44′) for compressing refrigerant starting from low pressure to medium pressure and at least one cylinder (46′) for compressing refrigerant from medium pressure to high pressure.
29. A refrigerant compressor unit in accordance with embodiment 28, wherein the cylinder head (140) has an inlet chamber (142′a) for refrigerant at low pressure, an outlet chamber (144′a) for refrigerant at medium pressure, an inlet chamber (142′b) for refrigerant at medium pressure and an outlet chamber (144′b) for refrigerant at high pressure.
30. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the cylinder head (140) is provided with a pressure relief valve (302) connected to the outlet chamber (144) for refrigerant compressed to high pressure.
31. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the cylinder head (140) is provided with a pressure relief valve (300) connected to the inlet chamber (142).
32. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the cylinder housing block (40, 40′) is arranged on the housing sleeve (16) in such a way that the cylinders (42, 44, 46, 42′, 44′, 46′) extend transversely to a vertical direction (348).
33. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the housing (12) is arranged in an operating position such that the cylinder housing block (40, 40′), the valve plate (120) and the cylinder head (140) are arranged relative to the housing sleeve (16) in a direction transverse to a vertical direction (348) on one side of the housing sleeve (16).
34. A refrigerant compressor unit in accordance with the preceding embodiments, wherein a lubricant bath (352) forming in the drive chamber (38) of the compressor housing portion (26) is arranged in the vertical direction (348) below the cylinders (42, 44, 46) and at a spacing therefrom.
35. A refrigerant compressor unit in accordance with the preceding embodiments, wherein a lubricant feed unit (354) is provided in the compressor housing portion (26) and receives lubricant from the motor compartment (158) and feeds it to the lubricant bath (352) in the compressor housing portion (26).
36. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the housing (12) is provided with at least two mounting lugs (332, 334, 336) which permit mounting of the housing (12) in such a way that the cylinder housing block (40), the valve plate (120) and the cylinder head (140) are arranged relative to the housing sleeve (16) in the direction transverse to a vertical direction (348) on one side on the housing sleeve.
37. A refrigerant compressor unit in accordance with embodiment 35, wherein the mounting lugs (332, 334, 336) are arranged on the housing sleeve (16).
38. A refrigerant compressor unit (10) in accordance with the preceding embodiments, wherein the stator (172) is mounted in the motor housing portion (28) by means of support elements (192, 194) which are installed into the motor compartment (158) and which, on the one hand, bear against a stator receiving surface (184) of the motor housing portion (28) and, on the other hand, surround the stator (172) installed into the support elements (192, 194) on its outer side (182) and support it resiliently relative to the stator receiving surface (184).
39. A refrigerant compressor unit in accordance with embodiment 38, wherein the support elements (192, 194) have resilient bodies (202) which are dimensioned such that they are in an elastically deformed state in all operating states of the motor housing portion (28) occurring during operation of the refrigerant compressor (10).
40. A refrigerant compressor unit in accordance with embodiment 38 or 39, wherein the support elements (192, 194) are arranged running around the stator (172) and each support the stator (172) on opposite sides of the rotor axis (178) several times relative to the stator receiving surface (184) of the motor housing portion (28).
41. A refrigerant compressor unit in accordance with embodiment 39 or 40, wherein the support elements (192, 194) have resilient bodies (202) arranged at defined angular intervals about the rotor axis (178).
42. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the resilient bodies (202) are positioned relative to each other by a band material (208) positioning them relative to each other and running around the stator (172).
43. A refrigerant compressor unit in accordance with embodiment 42, wherein the resilient bodies (202) are molded into the band material (208).
44. A refrigerant compressor unit in accordance with embodiment 42 or 43, wherein the band material (208) is formed as a ring-like clasp with open ends (210).
45. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the resilient bodies (202) have flank regions (224, 226, 234, 236) running at an acute angle to the outer side (182) of the stator (172) and/or to the stator receiving surface (184) between foot regions (228) and support regions (222), of which the one bears against the outer side (182) of the stator (172) and the other bears against the stator receiving surface (184).
46. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the resilient bodies (202) are successively molded into a resilient band material (208), so that successive support regions (222) bear against an outer side (182) of the stator (172) or against the stator receiving surface (184) and successive foot regions (228) bear against the stator receiving surface (184) or the outer side (182) of the stator (172).
47. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the resilient bodies (202) are located between edge regions (212, 214) arranged circumferentially around the stator (172) and the support regions (222) are connected to the edge regions (212, 214) by means of flank regions (234, 236) running at an acute angle to the outer side (182) of the stator (172) and/or to the stator mounting surface (184).
48. A refrigerant compressor unit in accordance with embodiment 47, wherein, on the one hand, the support regions (222) bear against the outer side (182) of the stator (172) or the stator receiving surface (184) and, on the other hand, the edge regions (212, 214) bear against the stator receiving surface (184) or the outer side (182) of the stator (172).
49. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the support elements (192, 194) are formed from a resilient material, in particular spring steel.
50. A refrigerant compressor unit in accordance with the preceding embodiments, wherein support elements (192, 194) arranged in succession in the direction of the rotor axis (178) are positioned at a spacing from one another in the motor housing portion (28) by means of a spacer element (244).
51. A refrigerant compressor unit in accordance with the preceding embodiments, wherein one of the support elements (192) is positioned with respect to its position in the motor housing portion (28) by a step (146) adjoining the stator receiving surface (184).
52. A refrigerant compressor unit in accordance with the preceding embodiments, wherein the refrigerant compressor unit is configured for CO2 as refrigerant.
Further features and advantages of the invention are the subject of the following description and the drawings of some exemplary embodiments.
An exemplary embodiment of a refrigerant compressor unit 10 according to the invention shown in
A compressor housing portion 26 adjoins the front-side cover 22, followed by a motor housing portion 28, which extends to the rear-side cover 24.
The front-side cover 22 preferably bears on one side against an end face 32 of the housing sleeve 16 and on the other side engages behind a front-side cylindrical surface 34 of the housing sleeve 16 which adjoins the end face 32 and extends coaxially to the center axis 14.
Furthermore, the front-side cover 22 forms a concave curvature 36 located within the cylinder surface 34 which encroaches into a working chamber arranged in the compressor housing portion 26, so that an appreciable region of the concave curvature 36 encroaches into the drive chamber 38 starting from the end face 32 and extends partially offset relative to the end face 32 in the direction of the drive chamber 38.
Furthermore, a cylinder housing block 40 is arranged in the compressor housing portion 26, which is arranged for example on one side of the center axis 14 and is integrally molded in one piece on the housing sleeve 16, and forms for example at least two, preferably three cylinders 42, 44, 46, which are arranged in succession in the cylinder housing block 40 in a row direction 48 parallel to the center axis 14.
Preferably, the cylinder housing block 40 is formed from the same material as the entire housing sleeve 16 and is integrally molded on or formed in the housing sleeve 16 in one piece, wherein the cylinder housing block 40 extends in a radial direction with respect to the housing sleeve 16 from an outer surface 52 in the direction of the central axis 14 to an inner surface 54 over at least one guide length of the cylinders 42, 44, 46.
The cylinder housing block 40 delimits the drive chamber 38 provided in the compressor housing portion 26 with its inner side 54.
Pistons 62, 64, 66 are movably guided in each of the cylinders 42, 44, 46, each of which has eccentrics 72, 74, 76 seated only on a common drive shaft 70, which in each case drives connecting rods 82, 84, 86 with the eccentrics 72, 74, 76, so that the eccentrics 72, 74, 76 and the connecting rods 82, 84, 86 form drive units 92, 94, 96 for the respective pistons 62, 64, 66 in order to move these in the cylinders 42, 44, 46 (
The pistons 62, 64, 66 could be guided in the respective cylinders 42, 44, 46 directly by means of guide surfaces 102, 104 and 106, formed by the cylinder housing block 40 itself.
In this case, however, a coating of the guide surfaces 102, 104, 106 is advantageous and reduces wear of the material of the cylinder block 40.
Preferably, however, cylinder liners 112, 114, 116 are inserted into the cylinder housing block and are manufactured from a more wear-resistant material than the material of the cylinder housing block 40 and each have a collar 113, 115, 117, each of which is seated in one of receptacles 107, 109, 111 of the cylinder block 40 adjoining the outer surface 52 of the cylinder block 40.
Preferably, however, the cylinder housing block 40 is manufactured from the same material as the housing sleeve 16 and, in particular, is also integrally molded in one piece on the housing sleeve 16, the housing sleeve 16 being manufactured from aluminum, preferably a cast aluminum alloy with silicon, for example AlSi9MgKT6, in order to save weight.
This means that no consideration needs to be given to the material of the housing sleeve 16 and the cylinder housing block 40 integrally molded on it with regard to wear resistance in the region of the cylinders 42, 44, 46, since the wear resistance for guiding the pistons 62, 64, 66 can be ensured by the cylinder liners 112, 114, 116 inserted into the cylinder housing block 40.
The individual cylinders 42, 44, 46 are closed off by a valve plate 120 bearing in a sealed manner on the outer side 52 of the cylinder housing block 14, which valve plate also fixes the cylinder liners 112, 114, 116 in the receptacles 107, 109, 111 by pressing on their collars 113, 115, 117 and, in particular, bears sealingly on the respective collars 113, 115, 117.
As shown in
The valve plate 120 is covered on a side facing away from the cylinders 42, 44, 46 by a cylinder head 140, which is seated in a sealed manner on the valve plate 120 and has an inlet chamber 142 opposite the inlet valves 122, 124, 126 and an outlet chamber 144 accommodating the outlet valves 132, 134, 136, the volume of the outlet chamber 144 preferably being larger than that of the inlet chamber in order to obtain a larger damping volume for pulsations in the region of the emerging refrigerant.
Preferably, the valve plate 120 is manufactured from steel.
Since the cylinder head 140 is exposed to high pressures and pressure pulsations and temperatures, particularly when using CO2 as a refrigerant, and thus an intermediate wall 146 between the inlet chamber 142 and the outlet chamber 144 as well as outer walls 148 thereof are exposed to high mechanical and thermal loads and in particular must ensure a tight seal with the valve plate 140, the cylinder head is preferably manufactured from a cast material comprising an iron-carbon alloy.
For example, the cast material can be cast steel.
However, it is preferable if the cast material of the cylinder head 140 is formed from cast iron.
A cast iron with graphite, in particular a cast iron with spheroidal graphite or vermicular graphite, is preferred.
The drive shaft 70 carrying the eccentrics 72, 74, 76 is mounted on the one hand in the front-side cover 22, in particular in a bearing receptacle 152, which is arranged on a side of the concave curvature 36 facing the drive chamber 38 and accommodates an end portion of the drive shaft 70 engaging in the bearing receptacle 152.
Furthermore, the drive shaft extends through the drive chamber 38 to an intermediate wall 156 of the housing sleeve 16, which is arranged between the drive chamber 38 and a motor compartment 158 formed in the housing sleeve 16.
In the region of the intermediate wall 156, the drive shaft 70 is also mounted in a bearing portion 162 of the drive shaft 70 which passes through the intermediate wall 156, wherein the intermediate wall 156 forms a bearing bush 164 for mounting the bearing portion 162.
The drive chamber 38 is thus delimited in the direction of the center axis 14 of the housing sleeve 16 on the one hand by the front-side cover 22 and on the other hand by the intermediate wall 156, so that a drive portion 166 of the drive shaft 70 carrying the eccentrics 72, 74, 76 extends between these in the drive chamber 38.
An electric motor, designated as a whole by 170, is arranged in the motor housing portion 28 of the housing sleeve 16 and has a stator 172, which is arranged non-rotatably in the motor compartment 158, and has a rotor 174, which is arranged non-rotatably on a rotor support portion 176 extending in the motor compartment 158 following the bearing portion 162.
As shown in
A gap 173 is formed here between the rotor 174 and the stator 172.
The stator 172 is preferably mounted in the motor housing portion 28, as shown in
Preferably, each of the support elements 192, 194, as shown for example in
However, it is also possible that the retaining elements 204 and 206 are supported on the outer surface 182 of the stator 172 and the elastically deformable bodies 202 are supported on the stator receiving surface 184 of the motor housing portion 28.
As shown by way of example in
By forming the support elements 192, 194 from a band material 208 with spaced-apart ends 210, these can be inserted into the stator receiving surface 184 without producing shavings.
In particular, the flank regions 234 and 236 form lead-free chamfers which enable assembly or disassembly of the stator 172 without producing shavings.
Preferably, the support elements 192, 194 allow the “hard” stator 172 to be mounted in the “soft” motor housing portion 28 if the latter is manufactured from light metal, in particular aluminum, without causing damage to the motor housing portion 28. The same applies when replacing the electric motor 102.
Moreover, the form of the housing sleeve 16 with a cross-sectional shape that is as circular-cylindrical as possible is also advantageous in this case, since in this case too the forces required to accommodate the electric motor 170 and the compressive forces in the motor housing portion 28 can be optimally taken up, in particular without significant radial expansion of the motor housing portion 28, so that exact mounting of the electric motor 102 by the support elements 192 and 194 is again possible.
Due to the flank regions 224 and 226 as well as 234 and 236 running with a slight gradient to the surface supporting them, in
Preferably, the resilient bodies 202 are formed such that they follow all variations of the radial spacing RA (
This makes it possible to keep the stator 172 coaxial to the rotor axis 178 at all times, regardless of the thermal and/or pressure-induced radial expansion of the motor housing portion 28 and the thermally induced radial expansion of the stator 172.
Such pressure-induced radial expansions of the motor housing portion 22 occur in particular due to the fact that the motor compartment 158 is pressurized and the housing sleeve 16 of the overall housing 12 is manufactured from light metal.
In addition to the pressure load on the motor housing portion 28, there is also a thermal expansion depending on the operating state of the stator 172 and the motor housing portion 28.
Since all such deformations, which result in a change in the radial spacing RA, are taken up by the resilient bodies 202 in the form of purely elastic deformations, an optimally small gap 173 between the rotor 174 and the stator 172 can be maintained regardless of the operating state of the refrigerant compressor.
Due to the fact that all elastic elements 202 are arranged, for example, in a band material 208 and are held in their positions relative to one another by the retaining elements 204 and 206, the retaining elements 204 and 206 can be located around the stator 172 in a virtually closed circumferential manner in planes extending perpendicularly to the rotor axis 178 and thereby hold the elastic elements 202 in defined positions relative to the outer side 182 of the stator 172 and to the stator receiving surface 184.
For exact positioning of the support elements 192 and 194 in the motor housing portion 28, a step 242 is preferably provided adjacent to the rotor mounting surface 184, namely on a side facing the drive chamber 22, which step 242 runs around the rotor axis 178 and serves to position one of the support elements 192 facing the drive chamber 38.
In order to be able to position the second support element 194 exactly relative to the first support element 192, it would in principle be conceivable to also provide a step in the motor housing portion 28, but this would mean a further weakening of a wall thickness of the motor housing portion 22.
For this reason, a spacer element 244 is provided between the support elements 192 and 194 as shown in
For example, the spacer element 244 is configured to bear against the stator receiving surface 184 of the motor housing portion 22 and to run partially or completely around the rotor axis 178 to maintain the support elements 192 and 194 in a relatively exact position over their entire path around the rotor axis 178.
For example, the support elements 192, 194 and/or the spacer element 244 are formed by annular sheet metal elements, in particular of band material 208, with spaced-apart ends 210, which have a tendency to expand in the radial direction, so that these sheet metal elements are automatically applied to the stator receiving surface 184 and are fixed by frictional engagement.
This allows the support elements 192, 194 and, if necessary, the spacer element 244 to be inserted into the stator receiving surface 184 without producing shavings.
For the electrical supply of the electric motor 170, a contact insert 252 is preferably provided in the rear-side cover 24, which accommodates electrical contact elements 254 that are passed through the rear-side cover 24 (
On a side facing away from the motor compartment 158, a contact plug 256 can be plugged onto the contact insert 252 and contact is thus made with all the contact elements 254 accommodated in the contact insert 252 for connecting the electric motor 170 to a power source or a converter 268.
Furthermore, a second contact insert 262 is provided in the rear-side cover 24 (
However, it is also possible to provide all electrical contact elements 254 and 264 in a correspondingly complex contact insert and a correspondingly formed contact plug.
In addition, the refrigerant connection 278 is also provided in the rear-side cover 24 (
The rear-side cover 24 also bears against an end face 282 formed by the housing sleeve 16 and encroaches into a cylindrical inner surface 284 of the housing sleeve 16.
For optimum space utilization, the rear-side cover 24 is provided with a convex curvature 286 extending outwards away from the end face 282 and is thus able to accommodate parts of winding heads 288 of the stator 172 and thus enable a compact form of the housing 12.
The routing of the refrigerant in the exemplary embodiment of the refrigerant compressor according to the invention described above can be described particularly advantageously with reference to the schematized representations of the refrigerant compressor according to
As shown in
In addition, the refrigerant flows from the channel 292 by means of a channel 296 into the drive chamber 38 to keep it at low pressure.
This inlet chamber of the cylinder head 140 is associated with a pressure relief valve 300 provided on the cylinder head 140 and capable of relieving any excess pressure occurring in the inlet chamber 142.
The refrigerant is then sucked up from the inlet chamber 142 by the refrigerant pistons 62, 64, 66 moving in the cylinders 42, 44, 46 and compressed so that the refrigerant then enters the outlet chamber 144 through the outlet valves 132, 134 and 136.
A pressure relief valve 302 is also associated with the outlet chamber 144 in order to relieve any excess pressure that may occur in the outlet chamber 144.
The refrigerant which then collects in the outlet chamber 144 and is compressed to high pressure then exits the cylinder head 140 by means of a high-pressure connection 304 and is discharged from this.
In a variant of the first exemplary embodiment shown in
In addition, a recess 322 extending transversely to the row direction 48 is arranged in particular on a side facing the motor housing portion 28.
Preferably, all recesses 312, 314, 316 and 318 extend from the outer surface 52 into the cylinder housing block 40V and extend without touching the cylinders 42, 44, 46 up to a base terminating the recesses 312, 314, 316, 318, 322 in the region near the inner side 54 of the cylinder housing block 40V.
The recesses 312, 314, 316, 318, 322 allow a reduction in weight on the one hand and also improve the behavior during thermal expansion in particular.
The recesses 312, 314, 316, 318 and 322 are covered by the valve plate and, with the exception of recess 312, are closed by it.
The recess 312 is arranged such that the channel 292 opens out into it and the channel 296 extends from it into the working chamber 38, while the valve plate 120 has the access opening 294, so that the refrigerant flows through the recess 312 at low pressure.
Furthermore, the respective collars 113, 115, 117 of the cylinder liners 112, 114 and 116 are preferably formed such that their regions extending transversely to the row direction 48 have a greater extent than their regions running parallel to the row direction 48.
With regard to the further features of the variant of the first exemplary embodiment, reference is made in full to the above description of the first exemplary embodiment.
As shown in
Thus, the mounting units 332 and 334 allow the fixing of retaining rails 342 and 344 for mounting on a substantially horizontal mounting surface 346, wherein a substantially horizontal course is to be understood as a course of the mounting surface 346 of plus/minus 20° relative to the horizontal.
Preferably, the compressor unit according to the invention is installed in such an installation position that the cylinder head 140 together with the cylinder housing block 40 extends in relation to a vertical direction 348, starting from the housing sleeve 16 and running transversely thereto, preferably approximately parallel to the mounting surface 346, so that an advantageous installation position of the refrigerant compressor unit 10 is thereby achieved, in which the maximum height of the refrigerant compressor unit 10 above the mounting surface 346 is defined by the maximum height of the housing sleeve 16 above the mounting surface 346.
Preferably, in this installation position, the cylinders 42, 44, 46 run transversely to the vertical direction 348 and the pistons 62, 64, 66 also move transversely to the vertical direction 348, for example in a direction of movement which forms an angle of between 70° and 110° with the vertical direction 348.
However, as an alternative to using the mounting lugs 332 and 334, it is also possible to use the mounting lugs 334 and 336 for mounting on a mounting surface running approximately parallel to the vertical direction, in which case the overall height of the refrigerant compressor unit in the vertical direction 348 is also defined by the maximum diameter of the housing sleeve 16.
When installed in this installation position, the lubricant bath 352 lies in the drive chamber 38 in such a way that it lies in the vertical direction 348 below the pistons 62, 64, 66, in the case shown the piston 66, and also lies below the position of the cylinders 42, 44, 46, so that the lubricant bath 352 does not impair compressor operation (
This is made possible in particular by the fact that all cylinders 42, 44, 46 are arranged in succession in the row direction 48.
Furthermore, a lubricant feed unit 354 is arranged such that a lubricant removal element 356, for example also comprising a non-return valve, opens out into the motor compartment 158, for example in the vertical direction 348 at a lowest point on the base side, in order to receive lubricant from the motor compartment 158 at this point and to supply it to an ejector 358, arranged in the drive chamber 38 and fed by lubricant from the region of the bearing bush 164 for the drive shaft 70, which ejector feeds the lubricant into an outlet line 358 in the motor compartment 38, the outlet 362 of which is preferably located in the vertical direction 348 above the lubricant bath 352.
Such a lubricant feed unit is described, for example, in DE 22 50 947 A, to which reference is made with regard to further details.
In a second exemplary embodiment, shown in
From this inlet chamber 142′b, the refrigerant is sucked in by the piston 66′ in the cylinder 46′, which sucks in the refrigerant supplied at medium pressure from the medium-pressure inlet chamber 142′b, compresses it to high pressure and feeds it to the outlet chamber 144′b, from which it then exits by means of the high-pressure connection 304′.
Preferably, however, the channel 292 is also open through the channel 298 in the direction of the drive chamber 38, so that the drive chamber 38 can advantageously be kept at medium pressure and thus the pressure differences acting on the pistons 62′ and 64′ and 66′ can be kept lower.
In a variant of the second exemplary embodiment, the cylinder housing block 40′ is also provided with the recesses 312, 314, 316, 318, 322, so that reference is made in this respect to the description of the variant of the first exemplary embodiment with
Furthermore, in particular in the second exemplary embodiment, mounting lugs corresponding to the mounting lugs 332, 334, 336 are also provided, in the same way as shown in
Such a mounting can be realized due to the cylinders 42′, 44′, 46′ arranged in succession in the row direction 48′, wherein the lubricant bath 352, as shown in
In addition—as in the first exemplary embodiment—a lubricant feed unit 354 is also provided, with reference also being made to the explanations for the first exemplary embodiment in conjunction with
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2023 121 141.2 | Aug 2023 | DE | national |
| 10 2023 122 080.2 | Aug 2023 | DE | national |
