EP4276311A2 - Semi-hermetic refrigerant compressor - Google Patents

Abstract

Around a semi-hermetic refrigerant compressor, comprising a reciprocating compressor and an electric motor, an overall housing which has a motor housing section for the electric motor and a compressor housing section for the reciprocating compressor, a suction-side refrigerant path leading from a suction connection on the overall housing to an inlet chamber of the reciprocating compressor and one from an outlet chamber of the reciprocating compressor In order to improve the pressure-side refrigerant path leading to a pressure connection on the overall housing in such a way that it works more efficiently, it is proposed that the electric motor is designed as a synchronous motor, in the rotor of which permanent magnets for the synchronous operation of the electric motor and a short-circuit cage for starting the electric motor in asynchronous operation are arranged.

Description

The invention relates to a semi-hermetic refrigerant compressor, comprising a reciprocating compressor and an electric motor, an overall housing which has a motor housing section for the electric motor and a compressor housing section for the reciprocating compressor, a suction-side refrigerant path leading from a suction connection on the overall housing to an inlet chamber of the reciprocating compressor, and one from an outlet chamber of the reciprocating compressor to a pressure connection on the entire housing leading to the pressure-side refrigerant path, wherein in the compressor housing section at least one cylinder of the reciprocating compressor is provided, which has a piston movable in a cylinder bore formed in the compressor housing section, a valve plate closing the cylinder bore and a valve plate which overlaps the valve plate and forms part of the compressor housing section Has cylinder head.

Such semi-hermetic refrigerant compressors are known from the prior art.

A semi-hermetic refrigerant compressor has the overall housing as an outer housing, with the electric motor in particular being arranged in a refrigerant atmosphere. A semi-hermetic refrigerant compressor is not provided with an outer encapsulation that completely encloses the reciprocating piston compressor and the electric motor, but that at least one compressor housing forming the cylinder housing itself represents the outer housing.

The problem with these is how to operate them more energy-efficiently.

This object is achieved according to the invention in a semi-hermetic refrigerant compressor in that the refrigerant compressor is provided with an externally controllable or controlled mechanical power control unit.

Such an externally controlled power control unit creates the possibility of controlling the compressor delivery capacity of the semi-hermetic refrigerant compressor by means of the mechanical power control unit without a frequency converter for the electric motor, which is inexpensive and efficient, and in addition, in particular, it opens up the possibility of reducing the mechanical loads on the reciprocating compressor .

In particular, it is provided that the mechanical power control unit connects the outlet-side refrigerant path with the inlet-side refrigerant path for power reduction in at least one cylinder.

This creates the possibility of operating the at least one cylinder in such a way that it does not contribute to the compressor delivery capacity.

This solution has the advantage that the mechanical load on the components of the reciprocating compressor is low when there is a reduction in performance, since the refrigerant flows back from the outlet side to the inlet side at a pressure level that is close to the inlet side and there are no large pressure fluctuations or even Pressure peaks and temperature peaks occur in the reciprocating compressor, which in particular also reduce the efficiency when power is reduced.

With regard to the arrangement of the mechanical power control unit, a wide variety of possible solutions are conceivable.

An advantageous solution provides for the mechanical power control unit to be arranged on the cylinder head, which has the advantage that the mechanical power control unit can easily interact with at least one of the cylinders.

It is particularly favorable if the mechanical power control unit is at least partially integrated into the at least one cylinder head.

In order to be able to interact as optimally as possible with at least one cylinder, it is preferably provided that the mechanical power control unit connects an outlet chamber in the cylinder head to an inlet chamber in the cylinder head by means of a connecting channel to reduce power.

This makes it possible for the power control unit to interact directly with the at least one cylinder assigned to the cylinder head, so that a compact design of the refrigerant compressor can be achieved with a power control unit installed in this way.

It is particularly expedient if the connecting channel is arranged integrated into the cylinder head, so that the space required for the interaction of the power control unit with the inlet chamber and the outlet chamber can also be optimized.

In particular, it is provided that the outlet chamber in the cylinder head is arranged directly adjacent to at least one outlet opening for the respective cylinder in the valve plate and thus in particular the outlet chamber also directly adjoins the valve plate and the outlet opening, in particular with the exhaust valve.

Furthermore, it is preferably provided that the inlet chamber in the cylinder head is arranged immediately adjacent to an inlet opening for the respective cylinder in the valve plate, so that the inlet chamber also directly adjoins the valve plate and the inlet opening.

A wide variety of possibilities are conceivable with regard to the way in which the mechanical power control unit opens or closes the connecting channel between the outlet chamber and the inlet chamber.

For example, it would be conceivable to use conventional slider designs.

A particularly advantageous solution provides that the mechanical power control unit has a closure piston for closing the connecting channel.

Such a closure piston creates the possibility of opening or closing the connecting channel, in particular with the shortest possible reaction time.

For reliable sealing, the closure piston is preferably sealed with a piston ring in a guide bore, in particular in the cylinder head.

In particular, it is provided that the closing piston can be placed on a sealing seat for closing the connecting channel, which extends enclosing the connecting channel, so that when the closing piston is placed on the sealing seat, the connecting channel is interrupted, while when the closing piston is lifted off the compression seat, the connecting channel is opened again .

In order to permanently achieve reliable closure, it is preferably provided that a sealing area of the closure piston that can be placed on the sealing seat is made of a metal that has a lower hardness than a metal from which the sealing seat is made, or vice versa.

The sealing seat can be arranged in a variety of ways.

A particularly advantageous and compact solution provides that the seal seat is arranged in a wall section of the cylinder head that separates the inlet chamber from the outlet chamber.

The sealing seat can either be designed as part of the wall section or the sealing seat is formed by a component inserted into the wall section of the cylinder head.

Preferably, the sealing seat is arranged in such a way that it is arranged in a wall section running above the valve plate and above the inlet chamber and thus in particular the sealing seat simultaneously represents an opening for the inlet chamber opposite the valve plate.

Furthermore, it is preferably also provided that the sealing seat simultaneously represents a mouth opening for the outlet chamber, so that a direct transition from the outlet chamber into the inlet chamber is realized through the sealing seat.

For a spatially compact arrangement, it has proven to be particularly advantageous if the seal seat is arranged on a side of the inlet chamber opposite the valve plate.

A quick change of the closure piston between the closed position and the open position is preferably possible if, starting from the sealing seat, the stroke of the closure piston is in the range of a quarter to half of the average diameter of the connecting channel.

With regard to the assignment of the mechanical power control unit to individual cylinders, no further information was provided in connection with the previous explanation of the individual embodiments.

One solution provides that the mechanical power control unit is assigned to a cylinder and that, if necessary, several mechanical power control units are provided for several cylinders, whereby a mechanical power control unit does not necessarily have to be assigned to each cylinder.

A favorable solution provides that a cylinder head has an inlet chamber and an outlet chamber for a cylinder bank comprising at least two cylinders.

In this case, several cylinders are combined to form a cylinder bank.

Advantageously, in such a solution it is provided that the respective mechanical power control unit is assigned to a bank of cylinders, in particular with at least two cylinders.

In the case of a refrigerant compressor with several cylinder banks, for example N cylinder banks, it is preferably provided that a mechanical power control unit is assigned to at least N-1 cylinder banks.

However, in order to be able to optimally reduce the performance of the refrigerant compressor, it is preferably provided that a mechanical performance control unit is assigned to each cylinder bank.

In order to avoid a backflow of high-pressure refrigerant and thus a pressure drop at the outlet connection element when power is reduced, a check valve is provided in the compressor housing section following the refrigerant paths that can be influenced by the mechanical power control unit.

Furthermore, it is preferably provided that the check valve has an outlet opening provided in the valve plate and a valve element that interacts with the valve plate, so that the valve plate can also be used to arrange and form the check valve.

In particular, it is provided that the valve element is held on the valve plate, so that the valve plate is used not only to form the inlet and outlet valves, but also to hold the valve element of the check valve.

With regard to the actuation of the closure piston, no further information was provided in connection with the previous explanation of the individual exemplary embodiments.

An advantageous solution provides that the closure piston is acted upon by a compression spring in the direction of its position interacting with the sealing seat, so that the compression spring ensures that the closure piston closes the connecting channel due to the effect of the compression spring, for example when the refrigerant compressor is not working .

Furthermore, it is preferably provided that the closure piston can be actuated by a pressure chamber, which can be acted upon either by suction pressure or by high pressure, depending on the external control of the power control unit, with the closure piston moving into its open position when the pressure chamber is acted upon by suction pressure and when the pressure chamber is acted upon The locking piston is acted upon by high pressure in the direction of its closed position in addition to the action of the compression spring.

A volume of the pressure chamber is in particular so small that in the open position of the closure piston it is smaller than a third, preferably smaller than a quarter, even better smaller than a fifth, more advantageously smaller than a Sixth and particularly advantageously smaller than a seventh and even more advantageously smaller than an eighth of the maximum volume of the pressure chamber in the closed position of the closure piston.

This dimensioning of the pressure chamber allows it to be changed quickly between the closed position and the open position, since the pressure only has to be changed in a small volume between suction pressure and high pressure.

To apply high pressure or suction pressure to the pressure chamber, a control unit is preferably provided, which is included in the power control unit and can be used to control the pressurization of the closure piston.

To carry out the power control of the refrigerant compressor, a power control is preferably provided, which controls the at least one power control unit in accordance with a required compressor delivery capacity.

The performance control is in particular connected to a higher-level system control and receives information from the system control about the required compressor delivery capacity.

According to this information about the required compressor delivery rate, the power control then controls the at least one or more power control units so that the refrigerant compressor provides the required compressor delivery rate, but does not provide an unnecessarily high compressor delivery rate.

For this purpose, the refrigerant compressor is designed so that its maximum compressor delivery rate is sufficient for the maximum compressor delivery rate required by the system control, and lower compressor delivery rates are achieved by reducing power using the at least one performance control unit.

In addition, a start-up control unit is preferably provided for the refrigerant compressor, in particular the refrigerant compressor is provided with a start-up control unit which controls a start-up of the electric motor, which in the solution according to the invention starts as an asynchronous motor until it has reached the synchronous speed, and then as a synchronous motor continues.

The start-up control unit can control the operation of the refrigerant compressor in different ways in order to start the electric motor in a suitable manner.

In particular, the starting control unit works in such a way that it operates the electric motor for starting with a winding connection that reduces the starting current.

This could be achieved, for example, by switching from a star connection during startup to a delta connection after startup.

An advantageous solution provides that the start-up control unit first energizes a first partial winding and then a second partial winding in a stator of the electric motor to start the electric motor.

Starting the electric motor with a first partial winding has the advantage that it makes it possible to reduce the starting current and thus, for example, avoid a heavy load on the electrical supply network due to an excessively high starting current.

Alternatively or additionally, the start-up control unit is designed such that it controls the power control when the electric motor starts up in such a way that the reciprocating compressor only works with a reduced compressor delivery capacity when the electric motor starts up.

It is particularly favorable for starting the electric motor if the start-up control controls the power control in such a way that the reciprocating compressor works with the smallest possible compressor delivery capacity when the electric motor starts up.

The smallest possible compressor delivery rate can be a compressor delivery rate at which one or more cylinders are still working.

A particularly favorable embodiment provides that the power of the reciprocating compressor can be controlled in such a way that, at the lowest possible compressor delivery rate, none of the cylinders compresses any more refrigerant, so that the torque required to start the reciprocating compressor is minimal.

In addition, an advantageous solution provides that the start-up control controls the power control in such a way that after synchronous operation of the electric motor has been achieved, the compressor delivery capacity is increased gradually, for example by switching on another cylinder or a further bank of cylinders or, if necessary, successively switching on additional cylinders or more Cylinder banks.

With regard to the operating states of the reciprocating compressor, no further information was provided in connection with the solution according to the invention.

In principle, the reciprocating piston compressor according to the invention can work with all refrigerants common for semi-hermetic refrigerant compressors.

However, the solution according to the invention creates particular advantages for the operation of the reciprocating compressor, in particular for the damage-free operation of the reciprocating compressor when the reciprocating compressor operates with a suction pressure in the range of 10 bar to 50 bar.

Furthermore, the solution according to the invention is also particularly advantageous with regard to the mechanical load on the reciprocating compressor when the reciprocating compressor operates at a high pressure in the range of 40 bar to 160 bar.

In particular, the refrigerant compressor according to the invention can be used particularly advantageously if the reciprocating piston compressor works with carbon dioxide as the refrigerant and is designed in particular for operation with carbon dioxide as the refrigerant.

Alternatively or additionally, the task mentioned above is achieved according to the invention in a semi-hermetic refrigerant compressor of the type described above in that the electric motor is designed as a synchronous motor, in the rotor of which permanent magnets for the synchronous operation of the electric motor and a short-circuit cage for starting the electric motor in asynchronous operation are arranged.

The advantage of the solution according to the invention can be seen in the fact that such an electric motor for driving a semi-hermetic refrigerant compressor has a higher energy efficiency, especially at full load and also at partial load. Furthermore, the advantage of such an electric motor is that the delivery volume is constant even in the high-load range due to the synchronous operation.

No further information has yet been provided regarding the design of the permanent magnets.

An advantageous solution provides that the permanent magnets extend parallel to a rotor axis of the rotor.

Furthermore, it is preferably provided that the permanent magnets are designed as plate bodies, the flat sides of which extend in a longitudinal direction and a transverse direction running transversely to the longitudinal direction.

The permanent magnets are expediently arranged in the rotor in such a way that their longitudinal direction extends parallel to the rotor axis.

Furthermore, the permanent magnets are preferably arranged in the rotor in such a way that their transverse directions extend along outer edges of a geometric polygon that is symmetrical to the rotor axis.

No further information has yet been provided regarding the magnetization of the permanent magnets.

An advantageous solution provides that the permanent magnets designed as plate bodies have a different magnetic polarity on their opposing flat sides, one of which faces the rotor axis and the other faces away from the rotor axis, so that flat magnetic poles are easily formed in the rotor are available for synchronous operation of the electric motor.

In principle, the electric motor can be cooled in a variety of ways.

An advantageous solution provides that the suction-side refrigerant path passes through the motor housing to cool the electric motor.

1. 1. Halbhermetischer Kältemittelverdichter, umfassend einen Hubkolbenverdichter (12) und einen Elektromotor (14), ein Gesamtgehäuse (10), welches einen Motorgehäuseabschnitt (24) für den Elektromotor und einen Verdichtergehäuseabschnitt (22) für den Hubkolbenverdichter (12) aufweist, einen von einem Sauganschluss (232) am Gesamtgehäuse (10) zu einer Einlasskammer (94) des Hubkolbenverdichters (12) führenden saugseitigen Kältemittelpfad und einen von einer Auslasskammer (96) des Hubkolbenverdichters (12) zu einem Druckanschluss (216) am Gesamtgehäuse (10) führenden druckseitigen Kältemittelpfad, wobei in dem Verdichtergehäuseabschnitt (22) mindestens ein Zylinder (82, 84) des Hubkolbenverdichters (12) vorgesehen ist, der einen in einer im Verdichtergehäuseabschnitt (22) ausgebildeten Zylinderbohrung (72, 74) bewegbaren Kolben (66, 68), eine die Zylinderbohrung (72, 74) abschließende Ventilplatte (88) und einen die Ventilplatte (88) übergreifenden und einen Teil des Verdichtergehäuseabschnitts (22) bildenden Zylinderkopf (92) aufweist, dadurch gekennzeichnet, dass der Elektromotor (14) als Synchronmotor ausgebildet ist, in dessen Rotor (272) Permanentmagnete (292) für den Synchronbetrieb des Elektromotors (14) und ein Kurzschlusskäfig (276) für das Anlaufen des Elektromotors (14) im Asynchronbetrieb angeordnet sind.
2. 2. Kältemittelverdichter nach Ausführungsform 1, dadurch gekennzeichnet, dass die Permanentmagnete (292) sich parallel zu einer Rotorachse (282) des Rotors (272) erstrecken.
3. 3. Kältemittelverdichter nach Ausführungsform 2, dadurch gekennzeichnet, dass die Permanentmagnete (292) als Plattenkörper ausgebildet sind, deren Flachseiten (294) sich in einer Längsrichtung (296) und einer quer zur Längsrichtung verlaufenden Querrichtung (298) erstrecken.
4. 4. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass die Permanentmagnete (292) sich jeweils mit ihrer Längsrichtung (296) parallel zur Rotorachse (282) erstrecken.
5. 5. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass die Permanentmagnete (292) sich mit ihren Querrichtungen (298) längs Außenkanten eines zur Rotorachse (282) symmetrischen geometrischen Vielecks erstrecken.
6. 6. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass die als Plattenkörper ausgebildeten Permanentmagnete (292) auf ihren einander gegenüberliegenden Flachseiten (294), von denen die eine der Rotorachse (282) zugewandt und die andere der Rotorachse (282) abgewandt ist, eine unterschiedliche magnetische Polarität (N, S) aufweisen.
7. 7. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass der saugseitige Kältemittelpfad das Motorgehäuse (24) zur Kühlung des Elektromotors (14) durchsetzt.
8. 8. Kältemittelverdichter nach dem Oberbegriff der Ausführungsform 1 oder nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass der Kältemittelverdichter mit einer extern gesteuerten mechanischen Leistungssteuereinheit (142) versehen ist.
9. 9. Kältemittelverdichter nach dem Oberbegriff der Ausführungsform 1 oder nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass die mechanische Leistungssteuereinheit (142) zur Leistungsreduktion bei mindestens einem Zylinder (82, 84) den auslassseitigen Kältemittelpfad mit dem einlassseitigen Kältemittelpfad verbindet.
10. 10. Kältemittelverdichter nach Ausführungsform 8 oder 9, dadurch gekennzeichnet, dass die mechanische Leistungssteuereinheit (142) an dem mindestens einen Zylinderkopf (92) angeordnet ist.
11. 11. Kältemittelverdichter nach Ausführungsform 10, dadurch gekennzeichnet, dass die mechanische Leistungssteuereinheit (142) zumindest teilweise in den mindestens einen Zylinderkopf (92) integriert ist.
12. 12. Kältemittelverdichter nach einer der Ausführungsformen 8 bis 11, dadurch gekennzeichnet, dass die mechanische Leistungssteuereinheit (142) zur Leistungsreduktion eine Auslasskammer (96) im Zylinderkopf (92) mit einer Einlasskammer (94) im Zylinderkopf (92) mittels eines Verbindungskanals (144) verbindet.
13. 13. Kältemittelverdichter nach Ausführungsform 12, dadurch gekennzeichnet, dass der Verbindungskanal (144) in den Zylinderkopf (92) integriert angeordnet ist.
14. 14. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass die Auslasskammer (96) im Zylinderkopf (92) unmittelbar angrenzend an mindestens eine Auslassöffnung (112, 114, 116, 118) für den jeweiligen Zylinder (82, 84) in der Ventilplatte (88) angeordnet ist.
15. 15. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass die Einlasskammer (94) im Zylinderkopf unmittelbar angrenzend an eine Einlassöffnung (102, 104, 106, 108) für den jeweiligen Zylinder (82, 84) der Ventilplatte (88) angeordnet ist.
16. 16. Kältemittelverdichter nach einer der Ausführungsformen 8 bis 15, dadurch gekennzeichnet, dass die mechanische Leistungssteuereinheit (142) zum Verschließen des Verbindungskanals (144) einen Verschlusskolben (152) aufweist.
17. 17. Kältemittelverdichter nach Ausführungsform 16, dadurch gekennzeichnet, dass der Verschlusskolben (152) zum Verschließen des Verbindungskanals (144) auf einen Dichtungssitz (148) aufsetzbar ist, der den Verbindungskanal (144) umschließend verläuft.
18. 18. Kältemittelverdichter nach Ausführungsform 16 oder 17, dadurch gekennzeichnet, dass ein Dichtungsbereich (154) des Verschlusskolbens (152) aus einem Metall hergestellt ist, das eine geringere Härte aufweist als ein Metall, aus dem der Dichtungssitz (148) hergestellt ist.
19. 19. Kältemittelverdichter nach Ausführungsform 17 oder 18, dadurch gekennzeichnet, dass der Dichtungssitz (148) in einem Wandabschnitt (124) des Zylinderkopfes (92) angeordnet ist, der die Einlasskammer (94) von der Auslasskammer (96) trennt.
20. 20. Kältemittelverdichter nach einer der Ausführungsformen 17 bis 19, dadurch gekennzeichnet, dass der Dichtungssitz (148) in einen über der Ventilplatte (88) und über der Einlasskammer (94) verlaufenden Wandabschnitt (124) angeordnet ist.
21. 21. Kältemittelverdichter nach einer der Ausführungsformen 17 bis 20, dadurch gekennzeichnet, dass der Dichtungssitz (148) auf einer der Ventilplatte (88) gegenüberliegenden Seite der Einlasskammer (94) angeordnet ist.
22. 22. Kältemittelverdichter nach einer der Ausführungsformen 17 bis 21, dadurch gekennzeichnet, dass ausgehend von dem Dichtungssitz (148) ein Hub des Verschlusskolbens (152) im Bereich von einem Viertel bis zu der Hälfte eines mittleren Durchmessers des Verbindungskanals (144) liegt.
23. 23. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass ein Zylinderkopf (92) eine Einlasskammer (94) und eine Auslasskammer (96) für eine mindestens zwei Zylinder (82, 84) umfassende Zylinderbank (86) aufweist.
24. 24. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass die jeweilige mechanische Leistungssteuereinheit (142) einer Zylinderbank (86) zugeordnet ist.
25. 25. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass bei N Zylinderbänken (86) des Kältemittelverdichters mindestens N-1 Zylinderbänken (86) eine mechanische Leistungssteuereinheit (142) zugeordnet ist.
26. 26. Kältemittelverdichter nach einer der Ausführungsformen 23 bis 25, dadurch gekennzeichnet, dass jeder Zylinderbank (86) eine mechanische Leistungssteuereinheit (142) zugeordnet ist.
27. 27. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass in dem Verdichtergehäuseabschnitt (22) im Anschluss an die durch die mechanische Leistungssteuereinheit (142) beeinflussbaren Kältemittelpfade ein Rückschlagventil (222) vorgesehen ist.
28. 28. Kältemittelverdichter nach Ausführungsform 27, dadurch gekennzeichnet, dass das Rückschlagventil (222) eine in der Ventilplatte (88) vorgesehene Auslassöffnung (212) und ein mit der Ventilplatte (88) zusammenwirkendes Ventilelement (224) aufweist.
29. 29. Kältemittelverdichter nach Ausführungsform 28, dadurch gekennzeichnet, dass das Ventilelement (224) an der Ventilplatte (88) gehalten ist.
30. 30. Kältemittelverdichter nach einer der Ausführungsformen 16 bis 29, dadurch gekennzeichnet, dass der Verschlusskolben (152) in Richtung seiner mit dem Dichtungssitz (148) zusammenwirkenden Stellung durch eine Druckfeder (166) beaufschlagt ist.
31. 31. Kältemittelverdichter nach einer der Ausführungsformen 16 bis 30, dadurch gekennzeichnet, dass der Verschlusskolben (152) durch eine Druckkammer (162) betätigbar ist, die je nach externer Ansteuerung der Leistungssteuereinheit (142) entweder durch Saugdruck oder durch Hochdruck beaufschlagbar ist.
32. 32. Kältemittelverdichter nach Ausführungsform 31, dadurch gekennzeichnet, dass die Druckkammer (162) in der Offenstellung des Verschlusskolbens (152) ein Volumen aufweist, das kleiner ist als ein Drittel, besser kleiner als ein Viertel des maximalen Volumens der Druckkammer (162) in der Verschlussstellung.
33. 33. Kältemittelverdichter nach einer der Ausführungsformen 8 bis 32, dadurch gekennzeichnet, dass eine von der Leistungssteuereinheit (142) umfasste Ansteuereinheit (182) vorgesehen ist, mit welcher die Druckbeaufschlagung des Verschlusskolbens (152) steuerbar ist.
34. 34. Kältemittelverdichter nach einer der Ausführungsformen 8 bis 33, dadurch gekennzeichnet, dass eine Leistungssteuerung (138) vorgesehen ist, welche die mindestens eine mechanische Leistungssteuereinheit (142) entsprechend einer geforderten Verdichter-Förderleistung ansteuert.
35. 35. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass eine Anlaufsteuereinheit (312) vorgesehen ist, welche einen Anlauf des Elektromotors (14) steuert.
36. 36. Kältemittelverdichter nach Ausführungsform 35, dadurch gekennzeichnet, dass die Anlaufsteuereinheit (312) den Elektromotor (14) zum Anlaufen mit einer anlaufstromreduzierenden Wicklungsverschaltung betreibt.
37. 37. Kältemittelverdichter nach Ausführungsform 35 oder 36, dadurch gekennzeichnet, dass die Anlaufsteuereinheit (312) zum Anlaufen des Elektromotors (14) zunächst eine erste Teilwicklung (256) und nachfolgend eine zweite Teilwicklung (258) in einem Stator (252) des Elektromotors (14) bestromt.
38. 38. Kältemittelverdichter nach einer der Ausführungsformen 35 bis 37, dadurch gekennzeichnet, dass die Anlaufsteuereinheit (312) die Leistungssteuerung (138) beim Anlaufen des Elektromotors (14) so ansteuert, dass der Hubkolbenverdichter (12) beim Anlaufen des Elektromotors (14) nur mit reduzierter Verdichter-Förderleistung arbeitet.
39. 39. Kältemittelverdichter nach Ausführungsform 38, dadurch gekennzeichnet, dass die Anlaufsteuereinheit (312) die Leistungssteuerung (138) derart ansteuert, dass der Hubkolbenverdichter (12) beim Anlaufen des Elektromotors (14) mit der kleinstmöglichen Verdichter-Förderleistung arbeitet.
40. 40. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass der Hubkolbenverdichter (12) mit einem Saugdruck im Bereich von 10 bar bis 50 bar arbeitet.
41. 41. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass der Hubkolbenverdichter (12) mit einem Hochdruck im Bereich von 40 bar bis 160 bar arbeitet.
42. 42. Kältemittelverdichter nach einer der voranstehenden Ausführungsformen, dadurch gekennzeichnet, dass der Hubkolbenverdichter (12) mit Kohlendioxid als Kältemittel arbeitet und insbesondere für den Betrieb mit Kohlendioxid als Kältemittel ausgelegt ist.

The above description of solutions according to the invention therefore includes in particular the various combinations of features defined by the following numbered embodiments:

1. 1. Semi-hermetic refrigerant compressor, comprising a reciprocating compressor (12) and an electric motor (14), an overall housing (10), which has a motor housing section (24) for the electric motor and a compressor housing section (22) for the reciprocating compressor (12), one of one Suction connection (232) on the overall housing (10) to an inlet chamber (94) of the reciprocating compressor (12) leading to a suction-side refrigerant path and a pressure-side refrigerant path leading from an outlet chamber (96) of the reciprocating compressor (12) to a pressure connection (216) on the overall housing (10). , wherein at least one cylinder (82, 84) of the reciprocating piston compressor (12) is provided in the compressor housing section (22), which has a piston (66, 68) movable in a cylinder bore (72, 74) formed in the compressor housing section (22), a Cylinder bore (72, 74) closing valve plate (88) and a cylinder head (92) which overlaps the valve plate (88) and forms part of the compressor housing section (22), characterized in that the electric motor (14) is designed as a synchronous motor, in which Rotor (272), permanent magnets (292) for the synchronous operation of the electric motor (14) and a squirrel cage (276) for starting the electric motor (14) in asynchronous operation are arranged.
2. 2. Refrigerant compressor according to embodiment 1, characterized in that the permanent magnets (292) extend parallel to a rotor axis (282) of the rotor (272).
3. 3. Refrigerant compressor according to embodiment 2, characterized in that the permanent magnets (292) are designed as plate bodies, the flat sides (294) of which extend in a longitudinal direction (296) and a transverse direction (298) running transversely to the longitudinal direction.
4. 4. Refrigerant compressor according to one of the preceding embodiments, characterized in that the permanent magnets (292) each extend with their longitudinal direction (296) parallel to the rotor axis (282).
5. 5. Refrigerant compressor according to one of the preceding embodiments, characterized in that the permanent magnets (292) extend with their transverse directions (298) along outer edges of a geometric polygon symmetrical to the rotor axis (282).
6. 6. Refrigerant compressor according to one of the preceding embodiments, characterized in that the permanent magnets (292) designed as plate bodies are on their opposite flat sides (294), one of which faces the rotor axis (282) and the other faces away from the rotor axis (282). , have a different magnetic polarity (N, S).
7. 7. Refrigerant compressor according to one of the preceding embodiments, characterized in that the suction-side refrigerant path passes through the motor housing (24) for cooling the electric motor (14).
8. 8. Refrigerant compressor according to the preamble of embodiment 1 or according to one of the preceding embodiments, characterized in that the refrigerant compressor is provided with an externally controlled mechanical power control unit (142).
9. 9. Refrigerant compressor according to the preamble of embodiment 1 or according to one of the preceding embodiments, characterized in that the mechanical power control unit (142) connects the outlet-side refrigerant path to the inlet-side refrigerant path to reduce the power of at least one cylinder (82, 84).
10. 10. Refrigerant compressor according to embodiment 8 or 9, characterized in that the mechanical power control unit (142) is arranged on the at least one cylinder head (92).
11. 11. Refrigerant compressor according to embodiment 10, characterized in that the mechanical power control unit (142) is at least partially integrated into the at least one cylinder head (92).
12. 12. Refrigerant compressor according to one of embodiments 8 to 11, characterized in that the mechanical power control unit (142) for power reduction has an outlet chamber (96) in the cylinder head (92) with an inlet chamber (94) in the cylinder head (92) by means of a connecting channel (144). connects.
13. 13. Refrigerant compressor according to embodiment 12, characterized in that the connecting channel (144) is arranged integrated into the cylinder head (92).
14. 14. Refrigerant compressor according to one of the preceding embodiments, characterized in that the outlet chamber (96) in the cylinder head (92) is immediately adjacent to at least one outlet opening (112, 114, 116, 118) for the respective cylinder (82, 84) in the valve plate (88) is arranged.
15. 15. Refrigerant compressor according to one of the preceding embodiments, characterized in that the inlet chamber (94) in the cylinder head is arranged immediately adjacent to an inlet opening (102, 104, 106, 108) for the respective cylinder (82, 84) of the valve plate (88). .
16. 16. Refrigerant compressor according to one of embodiments 8 to 15, characterized in that the mechanical power control unit (142) has a closure piston (152) for closing the connecting channel (144).
17. 17. Refrigerant compressor according to embodiment 16, characterized in that the closure piston (152) for closing the connecting channel (144) can be placed on a sealing seat (148) which runs enclosing the connecting channel (144).
18. 18. Refrigerant compressor according to embodiment 16 or 17, characterized in that a sealing region (154) of the closure piston (152) is made of a metal that has a lower hardness than a metal from which the sealing seat (148) is made.
19. 19. Refrigerant compressor according to embodiment 17 or 18, characterized in that the seal seat (148) is arranged in a wall section (124) of the cylinder head (92) which separates the inlet chamber (94) from the outlet chamber (96).
20. 20. Refrigerant compressor according to one of embodiments 17 to 19, characterized in that the sealing seat (148) is arranged in a wall section (124) running above the valve plate (88) and above the inlet chamber (94).
21. 21. Refrigerant compressor according to one of embodiments 17 to 20, characterized in that the sealing seat (148) is arranged on a side of the inlet chamber (94) opposite the valve plate (88).
22. 22. Refrigerant compressor according to one of embodiments 17 to 21, characterized in that, starting from the sealing seat (148), a stroke of the closure piston (152) is in the range from a quarter to half of an average diameter of the connecting channel (144).
23. 23. Refrigerant compressor according to one of the preceding embodiments, characterized in that a cylinder head (92) has an inlet chamber (94) and an outlet chamber (96) for a cylinder bank (86) comprising at least two cylinders (82, 84).
24. 24. Refrigerant compressor according to one of the preceding embodiments, characterized in that the respective mechanical power control unit (142) is assigned to a cylinder bank (86).
25. 25. Refrigerant compressor according to one of the preceding embodiments, characterized in that for N cylinder banks (86) of the refrigerant compressor, a mechanical power control unit (142) is assigned to at least N-1 cylinder banks (86).
26. 26. Refrigerant compressor according to one of embodiments 23 to 25, characterized in that each cylinder bank (86) is assigned a mechanical power control unit (142).
27. 27. Refrigerant compressor according to one of the preceding embodiments, characterized in that a check valve (222) is provided in the compressor housing section (22) following the refrigerant paths that can be influenced by the mechanical power control unit (142).
28. 28. Refrigerant compressor according to embodiment 27, characterized in that the check valve (222) has an outlet opening (212) provided in the valve plate (88) and a valve element (224) which interacts with the valve plate (88).
29. 29. Refrigerant compressor according to embodiment 28, characterized in that the valve element (224) is held on the valve plate (88).
30. 30. Refrigerant compressor according to one of embodiments 16 to 29, characterized in that the closure piston (152) is acted upon by a compression spring (166) in the direction of its position cooperating with the seal seat (148).
31. 31. Refrigerant compressor according to one of embodiments 16 to 30, characterized in that the closure piston (152) can be actuated by a pressure chamber (162), which can be acted upon either by suction pressure or by high pressure, depending on the external control of the power control unit (142).
32. 32. Refrigerant compressor according to embodiment 31, characterized in that the pressure chamber (162) in the open position of the closure piston (152) has a volume that is smaller than a third, preferably smaller than a quarter, of the maximum volume of the pressure chamber (162) in the Locking position.
33. 33. Refrigerant compressor according to one of embodiments 8 to 32, characterized in that a control unit (182) included in the power control unit (142) is provided, with which the pressurization of the closure piston (152) can be controlled.
34. 34. Refrigerant compressor according to one of embodiments 8 to 33, characterized in that a power control (138) is provided, which controls the at least one mechanical power control unit (142) in accordance with a required compressor delivery capacity.
35. 35. Refrigerant compressor according to one of the preceding embodiments, characterized in that a start-up control unit (312) is provided, which controls a start-up of the electric motor (14).
36. 36. Refrigerant compressor according to embodiment 35, characterized in that the start-up control unit (312) operates the electric motor (14) for starting with a starting current-reducing winding connection.
37. 37. Refrigerant compressor according to embodiment 35 or 36, characterized in that the start-up control unit (312) for starting the electric motor (14) first has a first partial winding (256) and subsequently a second partial winding (258) in a stator (252) of the electric motor (14 ) energized.
38. 38. Refrigerant compressor according to one of embodiments 35 to 37, characterized in that the start-up control unit (312) controls the power control (138) when the electric motor (14) starts up in such a way that the reciprocating piston compressor (12) only starts when the electric motor (14) starts up reduced compressor delivery capacity works.
39. 39. Refrigerant compressor according to embodiment 38, characterized in that the start-up control unit (312) controls the power control (138) in such a way that the reciprocating compressor (12) works with the smallest possible compressor delivery capacity when the electric motor (14) starts up.
40. 40. Refrigerant compressor according to one of the preceding embodiments, characterized in that the reciprocating piston compressor (12) operates with a suction pressure in the range of 10 bar to 50 bar.
41. 41. Refrigerant compressor according to one of the preceding embodiments, characterized in that the reciprocating piston compressor (12) operates at a high pressure in the range of 40 bar to 160 bar.
42. 42. Refrigerant compressor according to one of the preceding embodiments, characterized in that the reciprocating piston compressor (12) works with carbon dioxide as a refrigerant and is in particular designed for operation with carbon dioxide as a refrigerant.

Further features and advantages of the invention are the subject of the following description and the graphic representation of some exemplary embodiments.

Fig. 1

eine Seitenansicht eines Ausführungsbeispiels eines erfindungsgemäßen Kältemittelverdichters;

Fig. 2

eine Draufsicht in Richtung des Pfeils A in Fig. 1 auf den erfindungsgemäßen Kältemittelverdichter;

Fig. 3

eine Frontansicht des Ausführungsbeispiels des erfindungsgemäßen Kältem ittelverdichters;

Fig. 4

einen halbseitig versetzten Schnitt längs Linie 4-4 in Fig. 2;

Fig. 5

einen Längsschnitt durch den erfindungsgemäßen Kältemittelverdichter;

Fig. 6

einen Schnitt längs Linie 6-6 in Fig. 7;

Fig. 7

einen Schnitt längs Linie 7-7 in Fig. 6 bei einem geschlossenen Verbindungskanal zwischen Einlasskammer und Auslasskammer;

Fig. 8

einen Schnitt ähnlich Fig. 7 bei geöffnetem Verbindungskanal zwischen der Auslasskammer und der Einlasskammer;

Fig. 9

einen Schnitt längs Linie 9-9 in Fig. 5 durch einen Rotor des Elektromotors;

Fig. 10

eine schematische Darstellung eines Anlaufens des Elektromotors, und

Fig. 11

einen Schnitt ähnlich Fig. 7 durch ein zweites Ausführungsbeispiel.

Show in the drawing:

Fig. 1

a side view of an embodiment of a refrigerant compressor according to the invention;

Fig. 2

a top view in the direction of arrow A in Fig. 1 on the refrigerant compressor according to the invention;

Fig. 3

a front view of the exemplary embodiment of the refrigerant compressor according to the invention;

Fig. 4

a half-sided offset cut along the line 4-4 in Fig. 2 ;

Fig. 5

a longitudinal section through the refrigerant compressor according to the invention;

Fig. 6

a cut along line 6-6 in Fig. 7 ;

Fig. 7

a cut along line 7-7 in Fig. 6 with a closed connecting channel between the inlet chamber and outlet chamber;

Fig. 8

a cut similar Fig. 7 with the connecting channel between the outlet chamber and the inlet chamber open;

Fig. 9

a cut along line 9-9 in Fig. 5 by a rotor of the electric motor;

Fig. 10

a schematic representation of a start-up of the electric motor, and

Fig. 11

a cut similar Fig. 7 by a second embodiment.

An embodiment of a semi-hermetic refrigerant compressor according to the invention, shown in Fig. 1 to 5 , comprises an overall housing 10, in which a reciprocating compressor 12 and an electric motor 14 are arranged.

The overall housing 10 preferably comprises a compressor housing section 22, which represents an outer housing of the reciprocating compressor 12, and a motor housing section 24, which represents an outer housing of the electric motor 14.

The overall housing 10 is preferably formed by a one-piece housing body 26, which extends in the direction parallel to a central axis 28 explained in detail below and is closed at the end on the side of the compressor housing section 22 by means of a bearing cover 32 and in the area of the motor section 24 at the end with an end cover 34 is closed.

In the compressor housing section 22, a compressor shaft designated as a whole by 42 extends coaxially to the central axis 28 between a first shaft bearing 44 arranged on the bearing cover 32 to a second shaft bearing 46 arranged between the reciprocating compressor 12 and the electric motor 14, the second shaft bearing 46 being on an in The middle wall 48 is held in the housing body 26, which has a between the bearing cover 32 and the middle wall 48 drive space 52, through which the compressor shaft 42 extends and in which eccentrics 54 and 56 of the compressor shaft 42 are arranged, with two connecting rods 62 ₁ and 62 ₂ on each of the eccentrics 54 and 56, or 64 ₁ and 64 ₂ , are arranged, with the connecting rods 62 ₁ and 64 ₁ driving the pistons 66 ₁ and 68 ₁ and the connecting rods 62 ₂ and 64 ₂ driving the pistons 66 ₂ and 68 ₂ .

The pistons 66 and 68 are guided in cylinder bores 72 and 74, which are formed by cylinder housings 76, 78 which are formed into the compressor housing section 22, in particular in one piece.

Each cylinder housing 76, 78 with the cylinder bore 72, 74 and the piston 66, 68 guided therein each forms a cylinder 82, 84.

The two first cylinders 82 ₁ and 84 ₁ molded into the compressor housing section 22 form a first cylinder bank 86 ₁ , while the two cylinders 82 ₂ and 84 ₂ molded into the compressor housing section 22 form a second cylinder bank 86 ₂ .

In each of the cylinder banks 86 ₁ and 86 ₂ , the respective cylinder bores 72 ₁ and 74 ₁ or 72 ₂ and 74 ₂ are closed by a common valve plate 88 ₁ or 88 ₂ , which seals tightly on the respective cylinder housings 76 ₁ and 78 ₁ , or 76 ₂ and 78 ₂ , and thus limit the compression space enclosed by the respective valve plate 88 ₁ and 88 ₂ and the respective pistons 66 ₁ and 68 ₁ or 66 ₂ and 68 ₂ as well as the cylinder bores 72 ₁ and 74 ₁ or 72 ₂ and 74 ₂ .

The valve plates 88 ₁ and 88 ₂ are in turn covered by cylinder heads 92 ₁ and 92 ₂ , respectively.

In each of the cylinder heads 92 ₁ and 92 ₂ is as in the Fig. 6 to 8 shown, an inlet chamber 94 and an outlet chamber 96 are arranged, which are assigned to the two cylinders 82 and 84 of the respective cylinder bank 86.

In particular, the inlet chamber 94 lies over inlet openings 102 and 104 of the cylinder 82 and inlet openings 106 and 108 of the cylinder 84.

Furthermore, the outlet chamber 96 lies above outlet openings 112 and 114 of the cylinder 82 arranged in the valve plate 88 and outlet openings 116 and 118 of the cylinder 84, which are provided with outlet valves 113, 115, 117, 119 seated on the valve plate 88, and in particular is directly adjacent these on.

As in Fig. 6 to 8 shown, each cylinder head 92 comprises an outer body 122, which engages over the respective valve plate 88 and encloses the inlet chamber 94 and the outlet chamber 96, which in turn are separated from one another by a separating body 124 running within the outer body 122, the separating body 124 extending from the respective valve plate 88 rises and extends over and across the inlet chamber 94.

Thus, the outlet chamber 96 lies laterally next to the inlet chamber 94 in the area of the valve plate 88 and, however, extends between the outer body 122 and the separating body 124 at least in some areas above the inlet chamber 94.

To control the power, that is to say to control the compressor delivery capacity, of the refrigerant compressor, each cylinder head 92 is assigned a mechanical power control unit 142, which is actively controlled by a power control 138 and with which a connecting channel 144 between the outlet chamber 96 and the inlet chamber 94 is closed or opened can be, with the cylinders 82, 84 assigned to the cylinder head 92 with the connecting channel 144 ( Fig. 7 ) compress refrigerant at full power and do not compress refrigerant when the connecting channel 144 is open, since the refrigerant flows back from the outlet chamber 96 into the inlet chamber 94.

The connecting channel 144 runs through an insert part 146 inserted into the separating body 124, which forms a sealing seat 148 which faces the outlet chamber 96 and which adjoins a part of the outlet chamber 96 surrounding the sealing seat 148 and adjoining it.

Furthermore, the sealing seat 148 faces a closure piston 152, which can be placed on the sealing seat 148, for example with a metallic sealing area 154, in order to seal the connecting channel 144 tightly and which can be lifted off so far from the sealing seat 148 that the sealing area 154 is at a distance from the seal seat 148 and thus refrigerant can flow from the outlet chamber 96 into the inlet chamber 94.

Preferably, the closure piston 152 is guided coaxially to the insert part 146 with the seal seat 148 and sealed by means of a piston ring 153 in a guide bore 156, which is formed by a guide sleeve body 158 of the cylinder head 92 which is molded onto the outer body 122.

Preferably, the closure piston 152 itself or at least the sealing area 154 is made of a metal, for example a non-ferrous metal, which has a lower hardness than the metal of the seal seat 148, which is made for example of steel, in particular hardened steel.

In order to enable rapid movement of the closure piston 152, in particular a stroke of the closure piston 152 between a closed position and an open position is in the range between a quarter and half of an average diameter of the connecting channel 144.

The closure piston 152 delimits a pressure chamber 162, which is arranged on a side of the closure piston 152 facing away from the sealing area 154 and is closed by a closing body 164 on a side opposite the closure piston 152.

The volume of the pressure chamber 162 is in particular so small that in the open position of the closure piston it is smaller than a third, better smaller than a quarter, even better smaller than a fifth, advantageously smaller than a sixth and even more advantageously smaller than an eighth of the maximum Volume of the pressure chamber 162 in the closed position of the closure piston 152.

Furthermore, a compression spring 166 is arranged in the pressure chamber 162, which is supported on the end body 164 on the one hand and, on the other hand, acts on the closing piston 152 in the direction of its closed position resting on the sealing seat 148.

Depending on the pressurization of the pressure chamber 162, the closing piston 152 is in its in Fig. 8 shown open position or in its in Fig. 7 shown locking position movable.

For this purpose, the closure piston 152 is penetrated by a throttle channel 172, which extends from the pressure chamber 162 through the closure piston 152 to a mouth opening which is arranged radially outside of the sealing area 154 on a side facing the sealing seat 148, but in that this is radially outside the sealing element 154 lies, in the closed position of the closure piston 152 an entry of refrigerant under pressure in the outlet chamber 96 and flowing around the seal seat is permitted and this is throttled to the pressure chamber 162.

In addition, a relief channel 176 leads into the pressure chamber 162, for example through the closure body 164, which can be connected to a pressure relief channel 184, which is connected to the inlet chamber 94, through a solenoid valve designated as a whole by 182.

For example, the solenoid valve 182 is designed such that it has a valve body 186 with which the connection between the pressure relief channel 184 and the relief channel 176 can be interrupted or established.

If the connection between the relief channel 176 and the pressure relief channel 184 is established, the suction pressure predominates in the pressure chamber 162, while the closure piston 152 is acted upon by the pressure in the outlet chamber 96 on its side facing the outlet chamber 96 and is thus moved into its open position.

However, if the connection between the pressure relief channel 184 and the relief channel 176 is interrupted by the valve body 186, the compression spring 166 presses the closure piston 152 onto the sealing seat 148 and additionally high pressure flows through the throttle channel 172 into the pressure chamber 162, so that in the pressure chamber 162 High pressure builds up, which, in addition to the effect of the compression spring 166, presses the closure piston 152 with the sealing element 154 onto the seal seat 148.

In particular, the closing piston 152 is designed such that it extends radially beyond the sealing seat 148, so that even when the closing piston 152 is in the closed position, the piston surface lying radially outside the sealing seat 148 and subjected to high pressure This causes the closing piston 152 to move into the open position against the force of the compression spring 166, shown in Fig. 5 is moved if the valve body 186 of the solenoid valve 182 establishes the connection between the relief channel 176 and the pressure relief channel 184, which results in a suction pressure being established in the pressure chamber 162.

The supply of refrigerant under suction pressure takes place via a supply channel 202 formed in the compressor housing section 22, which leads to an inlet opening 204 leading to the valve plate 88, through which refrigerant under suction pressure flows to a passage opening 206 in the valve plate 88 and through this into the inlet chamber 94 passes.

Furthermore, as in Fig. 7 and 8th shown the outlet chamber 96 to an outlet opening 212 arranged in the valve plate 88 through which the refrigerant under pressure in the outlet chamber 96 passes into an outlet channel 214 provided in the compressor housing section 22 and can flow to an outlet connection element 216.

In particular, the outlet opening 212 of the valve plate 88 is assigned a check valve 222, which is held on the valve plate 88 and a valve element 224 is arranged on a side of the valve plate 88 facing the outlet channel 214 and ensures that in the case of the open position of the closing piston 152 and thus In the event of the refrigerant overflowing from the outlet chamber 96 into the inlet chamber 94, the pressure in the outlet channel 214 does not drop, but is maintained by the closing check valve 222.

Preferably, the check valve 222, together with a catch element 226 assigned to it, is held on the valve plate 88 by means of a holding element 228 and seals against the valve plate 88.

The refrigerant compressor according to the invention is designed as a semi-hermetic compressor, so that refrigerant under suction pressure is supplied to an engine compartment 234 by means of an inlet connection element 232 arranged on the end cover 34 and flows through the electric motor 14 in the direction of the middle wall 48 and passes from the engine compartment 234 into the supply channel 202, so that the supplied suction-side refrigerant cools the electric motor 14 in the engine compartment 234.

The electric motor 14 in turn comprises a stator 252 which is held firmly in the motor housing section 24 and has a stator winding 254, which has, for example, two partial windings 256 and 258 which are used to magnetize a stator laminated core 262.

The stator 252 encloses a rotor designated as a whole 272, in the rotor laminated core 274, as in Fig. 9 shown, on the one hand a short-circuit cage 276 is arranged, which comprises short-circuit bars 278 which run parallel to a rotor axis 282 and which are electrically conductively connected to one another at the ends in the circumferential direction.

Furthermore, plate-shaped permanent magnets 292 are inserted into the laminated core 274, the flat sides 294 of which extend on the one hand with a longitudinal direction 296 parallel to the rotor axis 282 and with a transverse direction 298 extend transversely to the rotor axis 282 in such a way that the transverse directions 298 extend around the rotor axis 282 as an axis of symmetry form a geometric polygon running around it.

The permanent magnets 292 are further designed such that in a direction of rotation 302 around the rotor axis 282, successive permanent magnets 292 each have an alternating polarity on their sides facing the rotor axis 282, so that overall the rotor 272 has alternating magnetic poles in the direction of rotation by means of the permanent magnets 292 .

An electric motor 14 provided with such a rotor 272 works as a synchronous motor in normal operation due to the permanent magnets 292 provided in the rotor 272, with such a synchronous motor having advantageous energy efficiency and higher refrigerant delivery capacity due to the permanent magnets 292.

The rotating field generated by the stator 252 rotates at a defined frequency due to a supply to the stator winding 254, which is caused, for example, by the fact that the stator winding 254 is fed by an AC network.

In order to enable starting with a rotating field of the stator 252 rotating at a constant frequency, the rotor 272 is provided with the short-circuit cage 276, which creates the possibility that the electric motor 14 initially starts as an asynchronous motor until it reaches the speed corresponding to the rotating field of the stator winding has reached and then rotates as a synchronous motor due to the magnetic poles caused by the permanent magnets 292.

A refrigerant compressor with such an electric motor can therefore be operated powered by a standard AC network, since it starts like an asynchronous motor.

However, it is also possible to operate such a refrigerant compressor with a frequency converter.

To make it easier to start the electric motor 14, there is also the possibility of using a start-up control 312 assigned to the refrigerant compressor - as in Fig. 10 shown - first to energize only one of the partial windings 256 or 258 in order to reduce the starting current and then, after a short starting phase of the electric motor 14 as an asynchronous motor, to switch the other of the partial windings 258, 256 to it.

If the refrigerant compressor according to the invention is used for large pressure differences, for example as a compressor for CO ₂ , the start-up control 312 intervenes in the intended power control 138 for the active control of the power control units 142 and causes at least one cylinder bank 86, preferably both cylinder banks 86 ₁ and 86 ₂ , can be deactivated, so that when at least one cylinder bank 86 is deactivated, the torque that the reciprocating compressor 12 requires is reduced, and when both cylinder banks 86 ₁ and 86 ₂ are deactivated, the torque that the reciprocating compressor 12 requires is low, since none Compression of refrigerant takes place so that, on the one hand, the starting current of the electric motor 14 is kept low and, on the other hand, it then changes very quickly from its operation as an asynchronous motor to operation as a synchronous motor in which the full torque is available, so that the cylinder banks either simultaneously or successively 86 ₁ and 86 ₂ can be activated ( Fig. 10 ).

In a second embodiment, shown in Fig. 11 Those parts that are identical to those of the first exemplary embodiment are provided with the same reference numerals, so that reference can be made in full to the statements on the first exemplary embodiment.

In contrast to the first exemplary embodiment, the catching element 226 'of the check valve 222' is formed in the compressor housing section 22, for example by a recess on the side of the outlet channel 214, which limits the possible path of the valve element 224' between its closed position resting on the valve plate 88 and the maximum open position Position limited.

Such a catching element 226 'can generally be provided in all compressor housing sections 22 of all refrigerant compressors of the same assembly, regardless of whether they are provided with a check valve 222' or not, so that the refrigerant compressor can be easily retrofitted with a check valve 222' and in particular also with at least a mechanical power control unit 142 according to the invention together with such a check valve 222 'is possible.

Claims (17)

Semi-hermetic refrigerant compressor, comprising a reciprocating compressor (12) and an electric motor (14), an overall housing (10), which has a motor housing section (24) for the electric motor and a compressor housing section (22) for the reciprocating compressor (12), one of a suction connection ( 232) on the overall housing (10) to an inlet chamber (94) of the reciprocating compressor (12) leading to a suction-side refrigerant path and a pressure-side refrigerant path leading from an outlet chamber (96) of the reciprocating compressor (12) to a pressure connection (216) on the overall housing (10), whereby at least one cylinder (82, 84) of the reciprocating piston compressor (12) is provided in the compressor housing section (22), which has a piston (66, 68) movable in a cylinder bore (72, 74) formed in the compressor housing section (22), a cylinder bore ( 72, 74) has a final valve plate (88) and a cylinder head (92) which extends over the valve plate (88) and forms part of the compressor housing section (22),
characterized in that the refrigerant compressor is provided with an externally controlled mechanical power control unit (142). Semi-hermetic refrigerant compressor, comprising a reciprocating compressor (12) and an electric motor (14), an overall housing (10), which has a motor housing section (24) for the electric motor and a compressor housing section (22) for the reciprocating compressor (12), one of a suction connection ( 232) on the overall housing (10) to an inlet chamber (94) of the reciprocating compressor (12) leading to the suction-side refrigerant path and a pressure-side path leading from an outlet chamber (96) of the reciprocating compressor (12) to a pressure connection (216) on the overall housing (10). Refrigerant path, wherein at least one cylinder (82, 84) of the reciprocating piston compressor (12) is provided in the compressor housing section (22), which has a piston (66, 68) movable in a cylinder bore (72, 74) formed in the compressor housing section (22). the cylinder bore (72, 74) has a valve plate (88) and a cylinder head (92) which overlaps the valve plate (88) and forms part of the compressor housing section (22), characterized in that the mechanical power control unit (142) for reducing power in at least one Cylinder (82, 84) connects the outlet-side refrigerant path with the inlet-side refrigerant path. Refrigerant compressor according to claim 1 or 2, characterized in that the mechanical power control unit (142) is arranged on the at least one cylinder head (92). Refrigerant compressor according to claim 3, characterized in that the mechanical power control unit (142) is at least partially integrated into the at least one cylinder head (92). Refrigerant compressor according to one of claims 1 to 4, characterized in that the mechanical power control unit (142) connects an outlet chamber (96) in the cylinder head (92) to an inlet chamber (94) in the cylinder head (92) by means of a connecting channel (144) to reduce power, in particular that the connecting channel (144) is arranged integrated into the cylinder head (92), in particular that the outlet chamber (96) in the cylinder head (92) is directly adjacent to at least one outlet opening (112, 114, 116, 118) for the respective cylinder (82 , 84) is arranged in the valve plate (88), in particular that the inlet chamber (94) in the cylinder head is arranged immediately adjacent to an inlet opening (102, 104, 106, 108) for the respective cylinder (82, 84) of the valve plate (88). is. Refrigerant compressor according to one of claims 1 to 5, characterized in that the mechanical power control unit (142) has a closing piston (152) for closing the connecting channel (144), in particular that the closing piston (152) for closing the connecting channel (144) has a sealing seat (148) can be placed, which runs enclosing the connecting channel (144), in particular that a sealing area (154) of the closure piston (152) is made of a metal that has a lower hardness than a metal from which the sealing seat (148) is made is, and/or that in particular the sealing seat (148) is arranged in a wall section (124) of the cylinder head (92) which separates the inlet chamber (94) from the outlet chamber (96) and/or that in particular the sealing seat (148) is in a wall section (124) running above the valve plate (88) and above the inlet chamber (94) is arranged and/or in particular the sealing seat (148) is arranged on a side of the inlet chamber (94) opposite the valve plate (88) and/or that, in particular, starting from the sealing seat (148), a stroke of the closure piston (152) is in the range of a quarter to half of an average diameter of the connecting channel (144). Refrigerant compressor according to one of the preceding claims,
characterized in that a cylinder head (92) has an inlet chamber (94) and an outlet chamber (96) for a cylinder bank (86) comprising at least two cylinders (82, 84). Refrigerant compressor according to one of the preceding claims, characterized in that the respective mechanical power control unit (142) is assigned to a cylinder bank (86), in particular in the case of N cylinder banks (86) of the refrigerant compressor, at least N-1 cylinder banks (86) have a mechanical power control unit (142) is assigned and / or that in particular each cylinder bank (86) is assigned a mechanical power control unit (142). Refrigerant compressor according to one of the preceding claims,
characterized in that a check valve (222) is provided in the compressor housing section (22) following the refrigerant paths that can be influenced by the mechanical power control unit (142), in particular that the check valve (222) has an outlet opening (212) provided in the valve plate (88). and has a valve element (224) which cooperates with the valve plate (88), in particular that the valve element (224) is held on the valve plate (88). Refrigerant compressor according to one of claims 6 to 9, characterized in that the closure piston (152) is acted upon by a compression spring (166) in the direction of its position cooperating with the seal seat (148). Refrigerant compressor according to one of claims 6 to 10, characterized in that the closure piston (152) can be actuated by a pressure chamber (162), which can be acted upon either by suction pressure or by high pressure, depending on the external control of the power control unit (142), in particular that the pressure chamber (162) in the open position of the closure piston (152) has a volume that is smaller than a third, preferably smaller than a quarter, of the maximum volume of the pressure chamber (162) in the closed position. Refrigerant compressor according to one of claims 1 to 11, characterized in that a control unit (182) included in the power control unit (142) is provided, with which the pressurization of the closure piston (152) can be controlled, in particular that a power control (138) is provided, which controls the at least one mechanical power control unit (142) in accordance with a required compressor delivery capacity. Refrigerant compressor according to one of the preceding claims,
characterized in that a start-up control unit (312) is provided, which controls a start-up of the electric motor (14), in particular that the start-up control unit (312) operates the electric motor (14) for starting with a starting current-reducing winding connection and/or in particular that the start-up control unit (312 ) to start the electric motor (14), first a first partial winding (256) and then a second partial winding (258) in a stator (252) of the electric motor (14) are energized. Refrigerant compressor according to claim 13, characterized in that the start-up control unit (312) controls the power control (138) when the electric motor (14) starts up in such a way that the reciprocating piston compressor (12) only works with a reduced compressor delivery capacity when the electric motor (14) starts up, that in particular the start-up control unit (312) controls the power control (138) in such a way that the reciprocating piston compressor (12) works with the smallest possible compressor delivery capacity when the electric motor (14) starts up. Refrigerant compressor according to one of the preceding claims,
characterized in that the reciprocating compressor (12) works with a suction pressure in the range of 10 bar to 50 bar and/or that in particular the reciprocating compressor (12) works with a high pressure in the range of 40 bar to 160 bar and/or that in particular the reciprocating compressor (12) works with carbon dioxide as a refrigerant and is designed in particular for operation with carbon dioxide as a refrigerant. Refrigerant compressor according to one of the preceding claims,
characterized in that the electric motor (14) is designed as a synchronous motor, in the rotor (272) of which permanent magnets (292) for the synchronous operation of the electric motor (14) and a short-circuit cage (276) for starting the electric motor (14) in asynchronous operation are arranged , in particular that the permanent magnets (292) extend parallel to a rotor axis (282) of the rotor (272), and/or that in particular the permanent magnets (292) are designed as plate bodies, the flat sides (294) of which extend in a longitudinal direction (296). and a transverse direction (298) extending transversely to the longitudinal direction, in particular that the permanent magnets (292) each extend with their longitudinal direction (296) parallel to the rotor axis (282), in particular that the permanent magnets (292) extend longitudinally with their transverse directions (298). Outer edges of a geometric polygon symmetrical to the rotor axis (282) extend, in particular that the permanent magnets (292) designed as plate bodies extend on their opposite flat sides (294), one of which faces the rotor axis (282) and the other faces away from the rotor axis (282). is, have a different magnetic polarity (N, S). Refrigerant compressor according to one of the preceding claims,
characterized in that the suction-side refrigerant path passes through the motor housing (24) to cool the electric motor (14).

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