Refrigerant Compressor Unit

Abstract

In order to make a refrigerant compressor unit as light and compact as possible so that it can be used as a transcritical CO2 compressor, it is proposed that the cylinder head is manufactured from a cast material comprising iron and that the housing sleeve, the compressor housing portion and a cylinder housing block, which accommodates the cylinders, as well as the motor housing portion form a single-piece part, in particular made of lightweight material.

Claims

1. 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 there are arranged 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, wherein the housing sleeve comprises a motor compartment with an electric motor arranged therein and driving the drive shaft, wherein a valve plate covering the cylinders is arranged on the housing sleeve and carries 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, wherein the cylinder head is manufactured from a cast material comprising iron, and wherein 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.

2. The refrigerant compressor unit in accordance with claim 1, wherein the cylinder head is manufactured from a cast material comprising an iron-carbon alloy.

3. The refrigerant compressor unit in accordance with claim 1, wherein the cylinder head is manufactured from cast steel.

4. The refrigerant compressor unit in accordance with claim 1, wherein the cylinder head is manufactured from cast iron.

5. The refrigerant compressor unit in accordance with claim 4, wherein the cylinder head is manufactured from cast iron with graphite.

6. The refrigerant compressor unit in accordance with claim 5, wherein the cylinder head is manufactured from cast iron with spheroidal graphite or vermicular graphite.

7. The refrigerant compressor unit in accordance with claim 1, wherein 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.

8. The refrigerant compressor unit in accordance with claim 1, wherein the housing sleeve with the compressor housing portion, the cylinder housing block and the motor housing portion is manufactured from a cast aluminum alloy with silicon.

9. The refrigerant compressor unit in accordance with claim 1, wherein 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.

10. The refrigerant compressor unit in accordance with claim 1, wherein the cylinders are arranged in succession in the cylinder housing block in a row direction, which in particular runs parallel to the drive shaft.

11. The refrigerant compressor unit in accordance with claim 1, wherein the cylinder housing block in addition to the cylinders also has recesses separate from the cylinders.

12. The refrigerant compressor unit in accordance with claim 1, wherein the housing sleeve has mounting openings at the ends, which are closed by housing covers.

13. The refrigerant compressor unit in accordance with claim 12, wherein the housing covers are manufactured from light metal, in particular aluminum.

14. The refrigerant compressor unit in accordance with claim 12, wherein the housing covers are curved.

15. The refrigerant compressor unit in accordance with claim 12, wherein one of the housing covers has a concave curvature extending into the housing sleeve.

16. The refrigerant compressor unit in accordance with claim 12, wherein one of the housing covers has a convex curvature curving away from the housing sleeve.

17. The refrigerant compressor unit in accordance with claim 12, wherein one of the housing covers is provided with at least one contact insert for passing through electrical connections.

18. The refrigerant compressor unit in accordance with claim 1, wherein one of the housing covers is provided with a refrigerant connection.

19. The refrigerant compressor unit in accordance with claim 1, wherein the housing sleeve is provided with an intermediate wall integrally molded thereon in one piece and separating the drive chamber from the motor compartment.

20. The refrigerant compressor unit in accordance with claim 19, wherein a bearing portion is provided in the intermediate wall for the drive shaft passing through it.

21. The refrigerant compressor unit in accordance with claim 1, wherein the cylinder head has a high-pressure connection for refrigerant.

22. The refrigerant compressor unit in accordance with claim 1, wherein the cylinder head has a connection for refrigerant at low pressure.

23. The refrigerant compressor unit in accordance with claim 1, wherein the sucked-in refrigerant flows through the motor compartment.

24. The refrigerant compressor unit in accordance with claim 23, wherein the refrigerant flowing through the motor compartment is fed through a channel to a passage opening in the valve plate.

25. The refrigerant compressor unit in accordance with claim 23, wherein the refrigerant enters an inlet chamber of the cylinder head after cooling the electric motor.

26. The refrigerant compressor unit in accordance with claim 24, wherein the channel is molded into the intermediate wall.

27. The refrigerant compressor unit in accordance with claim 24, wherein the channel is connected to a channel leading to the drive chamber.

28. The refrigerant compressor unit in accordance with claim 1, wherein the cylinder housing block has at least one cylinder for compressing refrigerant starting from low pressure to medium pressure and at least one cylinder for compressing refrigerant from medium pressure to high pressure.

29. The refrigerant compressor unit in accordance with claim 28, wherein 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.

30. The refrigerant compressor unit in accordance with claim 1, wherein the cylinder head is provided with a pressure relief valve connected to the outlet chamber for refrigerant compressed to high pressure.

31. The refrigerant compressor unit in accordance with claim 1, wherein the cylinder head is provided with a pressure relief valve connected to the inlet chamber.

32. The refrigerant compressor unit in accordance with claim 1, wherein the cylinder housing block is arranged on the housing sleeve in such a way that the cylinders extend transversely to a vertical direction.

33. The refrigerant compressor unit in accordance with claim 1, wherein the housing is arranged in an operating 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.

34. The refrigerant compressor unit in accordance with claim 1, wherein a lubricant bath forming in the drive chamber of the compressor housing portion is arranged in the vertical direction below the cylinders and at a spacing therefrom.

35. The refrigerant compressor unit in accordance with claim 1, wherein 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.

36. The refrigerant compressor unit in accordance with claim 1, wherein 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 on the housing sleeve.

37. The refrigerant compressor unit in accordance with claim 35, wherein the mounting lugs are arranged on the housing sleeve.

38. The refrigerant compressor unit in accordance with claim 1, wherein the stator is mounted in the motor housing portion by way of support elements which are installed into the motor compartment 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 and support it resiliently relative to the stator receiving surface.

39. The refrigerant compressor unit in accordance with claim 38, wherein the support elements 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.

40. The refrigerant compressor unit in accordance with claim 38, wherein the support elements are arranged running around the stator and each support the stator on opposite sides of the rotor axis several times relative to the stator receiving surface of the motor housing portion.

41. The refrigerant compressor unit in accordance with claim 39, wherein the support elements have resilient bodies arranged at defined angular intervals about the rotor axis.

42. The refrigerant compressor unit in accordance with claim 1, wherein the resilient bodies are positioned relative to each other by a band material positioning them relative to each other and running around the stator.

43. The refrigerant compressor unit in accordance with claim 42, wherein the resilient bodies are molded into the band material.

44. The refrigerant compressor unit in accordance with claim 42, wherein the band material is formed as a ring-like clasp with open ends.

45. The refrigerant compressor unit in accordance with claim 1, wherein the resilient bodies have flank regions running at an acute angle to at least one of i) the outer side of the stator and ii) the stator receiving surface between foot regions and support regions, of which the one bears against the outer side of the stator and the other bears against the stator receiving surface.

46. The refrigerant compressor unit in accordance with claim 1, wherein the resilient bodies are successively molded into a resilient band material, so that successive support regions bear against an outer side of the stator or against the stator receiving surface and successive foot regions bear against the stator receiving surface or the outer side of the stator.

47. The refrigerant compressor unit in accordance with claim 1, wherein the resilient bodies are located between edge regions arranged circumferentially around the stator and the support regions are connected to the edge regions by way of flank regions running at an acute angle to at least one of i) the outer side of the stator and ii) the stator receiving surface.

48. The refrigerant compressor unit in accordance with claim 47, wherein, on the one hand, the support regions bear against the outer side of the stator or the stator receiving surface and, on the other hand, the edge regions bear against the stator receiving surface or the outer side of the stator.

49. The refrigerant compressor unit in accordance with claim 1, wherein the support elements are formed from a resilient material, in particular spring steel.

50. The refrigerant compressor unit in accordance with claim 1, wherein support elements arranged in succession in the direction of the rotor axis are positioned at a spacing from one another in the motor housing portion by a spacer element.

51. The refrigerant compressor unit in accordance with claim 1, wherein 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.

52. The refrigerant compressor unit in accordance with claim 1, wherein the refrigerant compressor unit is configured for CO.sub.2 as refrigerant.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0143] FIG. 1 shows a section along line 1-1 in FIG. 2 through a first exemplary embodiment of a refrigerant compressor unit according to the invention;

[0144] FIG. 2 shows an enlarged view of the section according to FIG. 1 in the region of the cylinder housing block 40;

[0145] FIG. 3 shows a sectional view along line 3-3 in FIG. 1 through the first exemplary embodiment of the refrigerant compressor unit according to the invention, looking in the direction of arrow A;

[0146] FIG. 4 shows a schematic view of a detail of a stator bearing in a motor housing portion;

[0147] FIG. 5 shows a perspective view of one of the support elements of the stator bearing;

[0148] FIG. 6 shows a section along line 6-6 in FIG. 4;

[0149] FIG. 7 shows a schematic longitudinal section along line 7-7 in FIG. 8 through the first exemplary embodiment of the refrigerant compressor unit and an inlet chamber to explain the refrigerant routing in the first exemplary embodiment of the refrigerant compressor unit according to the invention;

[0150] FIG. 8 shows a sectional view along line 8-8 through the cylinder head in FIG. 7 looking in the direction of arrow B;

[0151] FIG. 9 shows a schematic longitudinal section along line 9-9 in FIG. 8 through the first exemplary embodiment of the refrigerant compressor unit according to the invention in the region of the outlet chamber;

[0152] FIG. 10 shows a top view of the housing sleeve in the direction of arrow C in FIG. 11;

[0153] FIG. 11 shows a longitudinal section along line 11-11 in FIG. 10 through the housing sleeve of a variant of the first exemplary embodiment;

[0154] FIG. 12 shows a perspective overall view of the first exemplary embodiment of the refrigerant compressor unit according to the invention in an installation position;

[0155] FIG. 13 shows a perspective overall view according to FIG. 12 of the first exemplary embodiment of the refrigerant compressor unit according to the invention in the installation position with the associated mounting elements;

[0156] FIG. 14 shows a section along line 14-14 in FIG. 12;

[0157] FIG. 15 shows a schematic longitudinal section along line 15-15 in FIG. 16 and similarly FIG. 7 through a second exemplary embodiment of the refrigerant compressor unit according to the invention, embodied as a two-stage compressor;

[0158] FIG. 16 shows a schematic representation similar to FIG. 8 through the second exemplary embodiment of the refrigerant compressor unit according to the invention, and

[0159] FIG. 17 shows a schematic longitudinal section along line 17-17 in FIG. 16 similar to FIG. 9 through the second exemplary embodiment of the refrigerant compressor unit according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0160] An exemplary embodiment of a refrigerant compressor unit 10 according to the invention shown in FIG. 1 comprises an overall housing 12, which has a housing sleeve 16 extending in the direction of a central axis 14, which extends from a front-side cover 22 closing a front-side mounting opening to a rear-side cover 24 closing a rear-side mounting opening.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] The cylinder housing block 40 delimits the drive chamber 38 provided in the compressor housing portion 26 with its inner side 54.

[0167] 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 (FIG. 1 and FIG. 2).

[0168] 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.

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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.

[0173] 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.

[0174] As shown in FIGS. 2 and 3, inlet valves 122, 124, 126 are arranged on the valve plate on the side where the cylinders 42, 44, 46 are arranged and outlet valves 132, 134, 136 for the respective cylinders 42, 44, 46 are arranged on a side facing away from the cylinders 42, 44, 46.

[0175] 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.

[0176] Preferably, the valve plate 120 is manufactured from steel.

[0177] 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.

[0178] For example, the cast material can be cast steel.

[0179] However, it is preferable if the cast material of the cylinder head 140 is formed from cast iron.

[0180] A cast iron with graphite, in particular a cast iron with spheroidal graphite or vermicular graphite, is preferred.

[0181] 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.

[0182] 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.

[0183] 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.

[0184] 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.

[0185] 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.

[0186] As shown in FIG. 1, an electric motor 170 is arranged in the motor compartment 158 of the overall housing 12, said motor compartment being located on a side of the intermediate wall 156 opposite the drive chamber 38, and has a stator 172, which is mounted non-rotatably in the motor housing portion 28, and a rotor 174, which is enclosed by the stator 172 and is seated on a rotor support portion 176 of the drive shaft 70, which is rotatable about a rotor axis 178, so that the rotor 174 is able to drive the drive shaft 70 by means of the rotor support portion 176 and thus also the pistons 62, 64, 66 by means of the drive units 92, 94, 96.

[0187] A gap 173 is formed here between the rotor 174 and the stator 172.

[0188] The stator 172 is preferably mounted in the motor housing portion 28, as shown in FIGS. 4, 5 and 6, by means of support elements 192 and 194 which act between an outer side 182 of the stator 172 and a stator receiving surface 184 of the motor housing portion 28 and which are resiliently deformable in the radial direction relative to the rotor axis 178 and support the stator 172 relative to the stator receiving surface 184.

[0189] Preferably, each of the support elements 192, 194, as shown for example in FIGS. 5 and 6, comprises resiliently deformable bodies 202 in the radial direction to the rotor axis 178, which for example support the stator 172 on the outer side 182, and retaining elements 204 and 206, which are arranged on both sides of the resiliently deformable bodies 202 as seen in the direction of the rotor axis 178, connect the resilient bodies 202 to one another and are supported on the stator receiving surface 184 of the motor housing portion 28.

[0190] 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.

[0191] As shown by way of example in FIGS. 5 and 6 in conjunction with the support element 192, these support elements 192, 194 can be realized by a band material 208 in the form of a ring-like clasp with spaced-apart ends 210, the edge regions 212 and 214 of which form the retaining elements 204 and 206 and in the central region 216 of which the elastically deformable bodies 202 are formed by structures embossed in the band material 208, which rise between the edge regions 212 and 214 and form support regions 222, which bear against the outer side 182 of the stator 172 and are connected in the circumferential direction about the rotor axis 178 to foot regions 228 by means of ascending flank regions 224 and 226 running at an acute angle to the surface supporting the outer side of the stator, in FIG. 5 to the stator receiving surface 184, which foot regions bear against the stator receiving surface 184, and, in the direction parallel to the rotor axis 178, are also connected to the edge regions 212 and 214, which also bear against the stator receiving surface 184, by means of flank regions 234 and 236 running at an acute angle to the supporting stator receiving surface 184.

[0192] 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.

[0193] In particular, the flank regions 234 and 236 form lead-free chamfers which enable assembly or disassembly of the stator 172 without producing shavings.

[0194] 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.

[0195] 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.

[0196] 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 FIG. 6 to the stator receiving surface 184, the resilient deformation of the deformable bodies 202 takes place primarily in the flank regions 224, 226 and 234 and 236, as shown in a dashed manner in FIG. 5 for the flank regions 224 and 226.

[0197] Preferably, the resilient bodies 202 are formed such that they follow all variations of the radial spacing RA (FIG. 6) between the outer side 182 of the stator 172 and the stator receiving surface 184 by elastic deformation, without plastic deformations occurring in the region of the resilient bodies 202, in particular the flank regions 224, 226 as well as 234 and 236.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] 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.

[0202] 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.

[0203] 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.

[0204] 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.

[0205] For this reason, a spacer element 244 is provided between the support elements 192 and 194 as shown in FIG. 4, which spacer element, for example, bears against the retaining elements 206 and 204 of the support element 194 or 192 and thus specifies the exact position of the second support element 194 relative to the first support element 192.

[0206] 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.

[0207] 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.

[0208] 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.

[0209] 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 (FIG. 1).

[0210] 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.

[0211] Furthermore, a second contact insert 262 is provided in the rear-side cover 24 (FIG. 1) and has additional electrical contact elements 264. Preferably, these additional contact elements 264 serve to establish electrical connections with sensors arranged in the overall housing 12, for example pressure sensors 272, and/or temperature sensors 274 and/or speed sensors 276, which serve to monitor the compressor function and the motor function, so that preferably an electrical supply line to all the sensors serving for the compressor function and/or the motor function and arranged in the overall housing 12 is provided by means of the contact insert 262 and a contact plug 266.

[0212] 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.

[0213] In addition, the refrigerant connection 278 is also provided in the rear-side cover 24 (FIG. 1) and can be used to supply refrigerant under low pressure directly to the motor compartment 158, specifically on a side opposite the drive chamber 38, said refrigerant flowing through the electric motor 170, cooling the electric motor and then entering the inlet chamber 142.

[0214] 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.

[0215] 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.

[0216] 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 FIG. 1 in FIGS. 7 to 9.

[0217] As shown in FIG. 7, the refrigerant to be compressed enters the motor compartment 158 through the refrigerant connection 278 and flows on the one hand through the gap 173 between the stator 172 and the rotor 174 and on the other hand along the outer side 182 of the stator 172 and the stator receiving surface 184 of the motor housing portion 28 on the outside of the stator 172 in the direction of the intermediate wall 156 between the drive chamber 38 and the motor compartment 158 and then by means of a channel 292 provided in the intermediate wall 156 in the direction of the valve plate, passes through an access opening 294 in the valve plate 120 and then enters the inlet chamber 142 of the cylinder head 140.

[0218] 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.

[0219] 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.

[0220] 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.

[0221] 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.

[0222] 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.

[0223] In a variant of the first exemplary embodiment shown in FIGS. 10 and 11, recesses 312, 314, 316 and 318 are arranged in the cylinder housing block 40V on opposite sides of the cylinders 42, 44, 46 arranged in succession in the row direction 48.

[0224] 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.

[0225] 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.

[0226] 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.

[0227] 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.

[0228] 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.

[0229] 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.

[0230] 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.

[0231] As shown in FIGS. 12 to 14, which show the first exemplary embodiment of the refrigerant compressor unit 10 according to the invention, in particular according to the variant thereof, the housing sleeve 16 in the vicinity of each of the front-side cover 22 and the rear-side cover 24 is provided with mounting lugs 332, 334, 336, which allow the refrigerant compressor unit 10 to be mounted on a wide variety of mounting surfaces.

[0232] 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.

[0233] 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.

[0234] 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.

[0235] 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.

[0236] 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 (FIG. 14).

[0237] This is made possible in particular by the fact that all cylinders 42, 44, 46 are arranged in succession in the row direction 48.

[0238] 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.

[0239] 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.

[0240] In a second exemplary embodiment, shown in FIGS. 15 to 17, the refrigerant compressor unit is constructed in principle identically to the first exemplary embodiment, but the cylinders 42 and 44 serve only to compress refrigerant at low pressure by means of a low-pressure connection 306 provided in the cylinder head 140, so that the refrigerant then entering the inlet chamber 142a is compressed by the pistons 62 and 64 in the cylinders 42, 44 to a medium pressure, with which the refrigerant then enters the outlet chamber 144a, leaves the outlet chamber 144a by means of a medium-pressure connection 308 and, if necessary after cooling, is supplied to the motor compartment 158 by means of the refrigerant connection 278, flows around the electric motor 170 on the one hand between rotor 174 and stator 172 and on the other hand on the outside of the stator 172 and enters a channel 292 in the intermediate wall 156, which leads on the one hand to the valve plate 20 and the passage 294 in the valve plate 20 and thus into an inlet chamber 142b for medium pressure.

[0241] From this inlet chamber 142b, 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 142b, compresses it to high pressure and feeds it to the outlet chamber 144b, from which it then exits by means of the high-pressure connection 304.

[0242] 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.

[0243] 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 FIGS. 10 and 11.

[0244] 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 FIGS. 12 to 14, so that retaining rails 342 and 344 can also be used for mounting on a substantially horizontal mounting surface 346 as in the first exemplary embodiment.

[0245] 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 FIG. 14, is then also located in the vertical direction 348 below the directions of movement of the pistons 62, 64 and 66 and the cylinders 42, 44 and 46 and a surface 353 of the lubricant bath 352 is arranged at a spacing from these, as shown in FIG. 14 in conjunction with the first exemplary embodiment.

[0246] In additionas in the first exemplary embodimenta lubricant feed unit 354 is also provided, with reference also being made to the explanations for the first exemplary embodiment in conjunction with FIG. 14.