Refrigerant compressor

Abstract

To operate a 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 port connected to a suction side of the reciprocating compressor, a pressure port connected to a pressure side of the reciprocating compressor, wherein at least one cylinder of the reciprocating compressor is provided in the compressor housing section, which has a piston movable in a cylinder bore formed in the compressor housing section and a valve plate closing the cylinder bore as well as a cylinder head overlapping the valve plate and forming part of the compressor housing section, in the most energy-efficient way possible, it is proposed that a mechanical power control unit be provided with which the suction side and the pressure side can be connected to each other for power reduction.and that a check valve is provided in the area of ​​the cylinder head, which allows a refrigerant flow exiting the cylinder head on the pressure side and blocks a refrigerant flow in the opposite direction.

Description

[0001] The invention relates to a refrigerant compressor, comprising a reciprocating piston 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 piston compressor, a suction connection connected to a suction side of the reciprocating piston compressor, a pressure connection connected to a pressure side of the reciprocating piston compressor, wherein at least one cylinder of the reciprocating piston compressor is provided in the compressor housing section, which cylinder has a piston movable in a cylinder bore formed in the compressor housing section and a valve plate closing the cylinder bore, as well as a cylinder head which overlaps the valve plate and forms part of the compressor housing section.

[0002] Such refrigerant compressors are known from the state of the art.

[0003] The problem with these refrigerant compressors is to operate them as energy-efficiently as possible while keeping their design as simple as possible.

[0004] This object is achieved according to the invention in a refrigerant compressor of the type described at the outset in that a mechanical power control unit is provided with which the suction side and the pressure side can be connected to one another in order to reduce power, and in that a check valve is provided in the region of the cylinder head which is held thereon and which allows a refrigerant flow emerging from the cylinder head and blocks a refrigerant flow opposite to this refrigerant flow.

[0005] Such an externally controlled power control unit provides the possibility of controlling the compressor 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 cost-effective and efficient, and in particular, it opens up the possibility of reducing the mechanical loads on the reciprocating compressor.

[0006] In particular, it is provided that the mechanical power control unit connects the outlet-side refrigerant path on the pressure side with the inlet-side refrigerant path on the suction side in order to reduce the power in at least one cylinder.

[0007] This makes it possible to operate at least one cylinder in such a way that it does not contribute to the compressor output.

[0008] This solution has the advantage that the mechanical load on the components of the reciprocating compressor is low when a power reduction occurs, since the refrigerant flows back from the pressure side to the suction side at a pressure level that is close to the inlet side and no large pressure fluctuations or even pressure peaks and temperature peaks occur in the reciprocating compressor, which in particular also reduce the efficiency when the power is reduced.

[0009] The advantage of this solution is also that the check valve in the area of ​​the cylinder head makes it possible to ensure that a pressure drop at the pressure connection can be avoided without complex design measures, in particular changes to the compressor housing section.

[0010] It is particularly advantageous if the check valve is arranged downstream of the outlet chamber and prevents refrigerant present downstream of the check valve from flowing back into the outlet chamber, thus limiting the volume relevant for the function of the mechanical power control unit to the volume of the outlet chamber.

[0011] For the spatial arrangement of the check valve, it is particularly advantageous if it is arranged at a distance from the valve plate on the cylinder head.

[0012] It is particularly advantageous if the check valve is arranged in an area of ​​the cylinder head facing away from the valve plate, since in this case it is possible to arrange the holder for the check valve in such a way that the check valve can be easily installed.

[0013] Preferably, the check valve is arranged in the region of a transition from the outlet chamber to an outlet-side refrigerant path, wherein in this solution the outlet-side refrigerant path can either lead directly away from the cylinder head or can still run partially within the cylinder head.

[0014] Furthermore, it is advantageously provided that the check valve is arranged and fixed in a receptacle provided on the cylinder head.

[0015] The provision of such a mount, in particular, allows for the simple installation of such a check valve. The mount can be mounted as a separate part on or in the cylinder head.

[0016] Another advantageous solution is that the mount is molded onto the cylinder head.

[0017] Furthermore, it is preferably provided that the check valve is arranged in a tightly sealed manner with the receptacle.

[0018] With regard to the design of the check valve itself, no further details have been given in connection with the previous explanation of the solution according to the invention.

[0019] For example, it would theoretically be conceivable to design the check valve as a valve tongue, similar to the inlet and outlet valves.

[0020] A further advantageous solution provides that the check valve has a valve body with at least one passage opening arranged therein and that the passage opening can be closed by a valve lamella that is movable relative to the valve body.

[0021] Because the check valve in this case has a valve body that carries the passage opening, it can be easily mounted as a whole in the holder.

[0022] Furthermore, it is preferably provided that the valve lamella is spring-loaded in the direction of a flow blocking position adjacent to a sealing surface of the valve body.

[0023] In particular, the valve lamella is acted upon by a separate spring element, so that the valve lamella itself does not have to provide the spring effect.

[0024] Furthermore, in order to achieve a permanently reliable function of the valve lamella, it is advantageous if the valve lamella is guided so that it can move relative to the valve body.

[0025] In order to achieve the largest possible opening cross-section in a flow release position, it is preferably provided that the valve lamella as a whole is at a distance from the valve body in the flow release position, so that the valve lamella as a whole travels the same path during the transition from the flow blocking position to the flow release position and can thus also provide the largest possible opening cross-section in the flow release position.

[0026] Furthermore, it is advantageously provided that the check valve has a catcher body for the valve lamella, which positions it in its flow release position, so that the position of the valve lamella in the flow release position can also be precisely specified.

[0027] Preferably, the catcher body is also designed in such a way that the spring element acting on the valve lamella is supported on it.

[0028] No further details have been provided so far regarding the further design of the check valve body.

[0029] An advantageous solution provides that the valve body is designed as an annular body, which thereby has an advantageous outer contour for the tight mounting of the same in the receptacle.

[0030] The ring body itself could be screwed into the holder.

[0031] However, it is also conceivable that the ring body is inserted into the holder with a fit and is fixed in the holder by separate fixing elements, for example one or more retaining rings.

[0032] When the valve body is designed as an annular body, it is further advantageously provided that the valve body has at least one passage opening arranged in an annular region around a central axis.

[0033] It is preferably provided that the valve body has a plurality of passage openings arranged around the central axis in the annular region.

[0034] In adaptation to the valve body designed as an annular body, the valve blade could be designed as a disc which can close at least one passage opening.

[0035] It is particularly advantageous if the valve blade is designed as an annular body in order to provide the largest possible flow cross-section in the flow release position due to a possible flow through the opening within the annular body.

[0036] In particular, it is provided that the valve blade is designed as an annular body which is arranged in the flow release position in such a way that refrigerant flows both over a radially outer outer edge of the annular body and over a radially inner inner edge of the annular body and thus the most favorable flow conditions are created in the flow release position.

[0037] With regard to the arrangement of the mechanical power control unit, no further details have been given in connection with the previous explanation of the solutions according to the invention.

[0038] Thus, an advantageous solution provides that the mechanical power control unit is arranged on the at least one cylinder head, which has the advantage that the mechanical power control unit can interact in a simple manner with at least one of the cylinders.

[0039] It is particularly advantageous if the mechanical power control unit is at least partially integrated into at least one cylinder head.

[0040] 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 for power reduction connects an outlet chamber in the cylinder head with an inlet chamber in the cylinder head by means of a controllable connecting channel.

[0041] This enables direct interaction of the power control unit with the at least one cylinder assigned to the cylinder head, so that a compact design of the refrigerant compressor can be realized with a power control unit installed in this way.

[0042] 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.

[0043] In particular, it is provided that an 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 is also directly adjacent to the valve plate and the outlet opening, in particular with the outlet valve.

[0044] Furthermore, it is preferably provided that an inlet chamber in the cylinder head is arranged directly 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.

[0045] There are many different possibilities as to how the mechanical power control unit opens or closes the connecting channel between the outlet chamber and the inlet chamber.

[0046] For example, it would be conceivable to use a conventional slide valve construction.

[0047] A particularly advantageous solution provides that the mechanical power control unit has a closing piston for closing the connecting channel.

[0048] Such a closure piston makes it possible to open or close the connecting channel, particularly with the shortest possible reaction time.

[0049] For reliable sealing, the closure piston is preferably sealed with a piston ring and guided in a guide bore, particularly in the cylinder head.

[0050] In particular, it is provided that the closure piston for closing the connecting channel can be placed on a sealing seat which extends around the connecting channel, so that when the closure piston is placed on the sealing seat the connecting channel is interrupted, while when the closure piston is lifted off the compression seat the connecting channel is opened again.

[0051] In order to achieve a permanently 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.

[0052] The seal seat can be arranged in a variety of ways.

[0053] A particularly advantageous and compact solution provides that the sealing seat is arranged in a wall section of the cylinder head that separates the inlet chamber from the outlet chamber.

[0054] The sealing seat can either be formed as part of the wall section or the sealing seat is formed by a component inserted into the wall section of the cylinder head.

[0055] 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 inlet opening for the inlet chamber opposite the valve plate.

[0056] Furthermore, it is preferably also provided that the sealing seat simultaneously represents an opening for the outlet chamber, so that a direct transition from the outlet chamber to the inlet chamber is realized through the sealing seat.

[0057] For a spatially compact arrangement, it has proven particularly advantageous if the sealing seat is arranged on a side of the inlet chamber opposite the valve plate.

[0058] A rapid 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 one quarter to one half of an average diameter of the connecting channel.

[0059] With regard to the assignment of the mechanical power control unit to individual cylinders, no further details were given in connection with the previous explanation of the individual embodiments.

[0060] One solution provides that the mechanical power control unit is assigned to a cylinder and that, if there are several cylinders, several mechanical power control units are provided, although it is not necessarily necessary to assign a mechanical power control unit to each cylinder.

[0061] A favorable solution provides for a cylinder head to have an inlet chamber and an outlet chamber for a cylinder bank comprising at least two cylinders.

[0062] In this case, several cylinders are combined to form a cylinder bank.

[0063] Advantageously, such a solution provides that the respective mechanical power control unit is assigned to a cylinder bank, in particular with at least two cylinders.

[0064] In a refrigerant compressor with several cylinder banks, for example N cylinder banks, it is preferably provided that at least N-1 cylinder banks are assigned a mechanical power control unit.

[0065] However, in order to be able to optimally reduce the power of the refrigerant compressor, it is preferably provided that each cylinder bank is assigned a mechanical power control unit.

[0066] With regard to the operation of the locking piston, no further details were given in connection with the previous explanation of the individual embodiments.

[0067] An advantageous solution provides that the closure piston is acted upon by a compression spring in the direction of its position cooperating 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 operating.

[0068] Furthermore, it is preferably provided that the closure piston is actuated by a pressure chamber which, depending on the external control of the power control unit, can be acted upon either by suction pressure or by high pressure, wherein when the pressure chamber is acted upon by suction pressure, the closure piston moves into its open position and when the pressure chamber is acted upon by high pressure, the closure piston is acted upon in the direction of its closed position in addition to the effect of the compression spring.

[0069] In particular, a volume of the pressure chamber is so small that, in the open position of the closure piston, it is less than one third, preferably less than one quarter, even better less than one fifth, more advantageously less than one sixth, particularly advantageously less than one seventh, and even more advantageously less than one eighth of the maximum volume of the pressure chamber in the closed position of the closure piston.

[0070] This dimensioning of the pressure chamber allows for quick switching between the closed and open positions, since the pressure only needs to be changed in a small volume between suction pressure and high pressure.

[0071] For the respective application of high pressure or suction pressure to the pressure chamber, a control unit is preferably provided which is included in the power control unit and with which the pressurization of the closure piston can be controlled.

[0072] 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 rate.

[0073] The power control is particularly connected to a higher-level system control and receives information from the system control about the required compressor output.

[0074] According to this information about the required compressor capacity, the capacity control then controls the at least one or more capacity control units in such a way that the refrigerant compressor delivers the required compressor capacity, but does not deliver an unnecessarily high compressor capacity.

[0075] For this purpose, the refrigerant compressor is designed in such a way that its maximum compressor delivery capacity is sufficient for the maximum compressor delivery capacity required by the system control system, and lower compressor delivery capacities are achieved by reducing the capacity by means of at least one capacity control unit.

[0076] With regard to the operating conditions of the reciprocating compressor, no further details were given in connection with the solution according to the invention.

[0077] In principle, the reciprocating compressor according to the invention can operate with all refrigerants commonly used for semi-hermetic refrigerant compressors.

[0078] 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.

[0079] Furthermore, the solution according to the invention is also particularly advantageous with regard to the mechanical load on the reciprocating piston compressor when the reciprocating piston compressor operates at a high pressure in the range of 40 bar to 160 bar.

[0080] In particular, the refrigerant compressor according to the invention can be used particularly advantageously if the reciprocating piston compressor operates with carbon dioxide as refrigerant and is designed in particular for operation with carbon dioxide as refrigerant.

[0081] Alternatively or additionally, the object mentioned at the outset is achieved according to the invention in a semi-hermetic refrigerant compressor of the type described at the outset 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 squirrel cage for starting the electric motor in asynchronous operation are arranged.

[0082] The advantage of the solution according to the invention is that such an electric motor for driving a semi-hermetic refrigerant compressor has higher energy efficiency, particularly at full load and also at partial load. Furthermore, the advantage of such an electric motor is that, thanks to synchronous operation, the displacement remains constant even in the high-load range.

[0083] In principle, the electric motor can be cooled in a variety of ways.

[0084] An advantageous solution provides for the suction-side refrigerant path to pass through the motor housing to cool the electric motor.

[0085] The object mentioned at the outset is further achieved by a cylinder head for a refrigerant compressor, in particular a reciprocating piston compressor, for mounting on a valve plate which closes off at least one cylinder bore and overlaps said bore with an open side, so that said cylinder head delimits an inlet chamber arranged between the valve plate and the cylinder head and an outlet chamber, characterized in that a mechanical power control unit is provided, with which an inlet chamber and an outlet chamber can be connected to one another in order to reduce power, and in that a check valve is provided in the region of the cylinder head and is held thereon, which check valve allows a refrigerant flow emerging from the cylinder head and blocks a refrigerant flow opposite to this refrigerant flow emerging.

[0086] Further designs of the cylinder head result from the features described above in connection with the refrigerant compressor.

[0087] The above description of solutions according to the invention thus includes in particular the various combinations of features defined by the following numbered embodiments: 1. Refrigerant compressor, comprising a reciprocating piston compressor (12) and an electric motor (14), an overall housing (10) which has a motor housing section (24) for the electric motor (14) and a compressor housing section (22) for the reciprocating piston compressor (12), a suction connection (272) connected to a suction side of the reciprocating piston compressor (12) and a pressure connection (216, 260', 260", 260"') connected to a pressure side of the reciprocating piston compressor (12), wherein at least one cylinder (82, 84) of the reciprocating piston compressor (12) is provided in the compressor housing section (22), which cylinder has a piston (66, 68) movable in a cylinder bore (72, 74) formed in the compressor housing section (22) and a valve plate (88) closing the cylinder bore (72, 74) and a valve plate (88) and forming part of the compressor housing section (22), wherein a mechanical power control unit (142) is provided,with which the suction side and the pressure side can be connected to one another to reduce power, wherein in the region of the cylinder head (92) a check valve (220) is provided which is held thereon, which allows a refrigerant flow exiting the cylinder head (92) on the pressure side and blocks a refrigerant flow opposite to this exiting refrigerant flow. 2. Refrigerant compressor according to embodiment 1, wherein the check valve (220) is arranged downstream of the outlet chamber (96) and prevents a backflow of refrigerant following the check valve (220) on the pressure side into the outlet chamber (96). 3. Refrigerant compressor according to embodiment 1 or 2, wherein the check valve (220) is arranged at a distance from the valve plate (88) on the cylinder head (92). 4. Refrigerant compressor according to one of the preceding embodiments,wherein the check valve (220) is arranged in a region of the cylinder head (92) facing away from the valve plate (88). 5. Refrigerant compressor according to one of the preceding embodiments, wherein the check valve (220) is arranged in the region of a transition from the outlet chamber (96) into an outlet-side refrigerant path (210). 6. Refrigerant compressor according to one of the preceding embodiments, wherein the check valve (220) is arranged and fixed in a receptacle (258) arranged on the cylinder head (92). 7. Refrigerant compressor according to one of the preceding embodiments, wherein the receptacle (258) is integrally formed on the cylinder head (92). 8. Refrigerant compressor according to one of the preceding embodiments, wherein the check valve (220) is arranged in a tightly sealed manner with the receptacle (258). 9. Refrigerant compressor according to one of the preceding embodiments,wherein the check valve (220) has a valve body (222) with at least one passage opening (226) arranged therein, and wherein the passage opening (226) can be closed by a valve blade (234) that is movable relative to the valve body (222). 10. Refrigerant compressor according to embodiment 9, wherein the valve blade (234) is spring-loaded in the direction of a flow-blocking position in which the valve blade (234) bears against a sealing surface (232) of the valve body (222). 11. Refrigerant compressor according to embodiment 9 or 10, wherein the valve blade (234) is guided so as to be movable relative to the valve body (222). 12. Refrigerant compressor according to embodiment 11, wherein the valve blade (234) is spaced apart from the valve body (222) as a whole in a flow-release position. 13. Refrigerant compressor according to one of embodiments 9 to 12, wherein the check valve (220) has a catcher body (242) for the valve blade (234),which positions them in their flow-release position. 14. Refrigerant compressor according to one of embodiments 9 to 13, wherein the valve body (222) is designed as an annular body. 15. Refrigerant compressor according to embodiment 14, wherein the valve body (222) has at least one passage opening (226) arranged in an annular region around a central axis (224). 16. Refrigerant compressor according to embodiment 15, wherein the valve blade (234) is designed as an annular body. 17. Refrigerant compressor according to embodiment 16, wherein the valve blade (234) in its flow-release position is surrounded by refrigerant flowing through the passage openings (226) both in the region of its inner edge (252) and in the region of its outer edge (254). 18. Refrigerant compressor according to one of the preceding embodiments, wherein the mechanical power control unit (142) is arranged on the at least one cylinder head (92). 19. Refrigerant compressor according to embodiment 18,wherein the mechanical power control unit (142) is at least partially integrated into the at least one cylinder head (92). 20. Refrigerant compressor according to one of the preceding embodiments, wherein 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 controllable connecting channel (144) for power reduction. 21. Refrigerant compressor according to embodiment 20, wherein the connecting channel (144) is arranged integrated into the cylinder head (92). 22. Refrigerant compressor according to one of the preceding embodiments, wherein an outlet chamber (96) in the cylinder head (92) is arranged directly adjacent to at least one outlet opening (112, 114, 116, 118) for the respective cylinder (82, 84) in the valve plate (88). 23. Refrigerant compressor according to one of the preceding embodiments,wherein an inlet chamber (94) is arranged in the cylinder head directly adjacent to an inlet opening (102, 104, 106, 108) for the respective cylinder (82, 84) of the valve plate (88). 24. Refrigerant compressor according to one of the preceding embodiments, wherein the mechanical power control unit (142) has a closing piston (152) for closing the connecting channel (144). 25. Refrigerant compressor according to embodiment 24, wherein the closing piston (152) for closing the connecting channel (144) can be placed onto a sealing seat (148) which extends surrounding the connecting channel (144). 26. Refrigerant compressor according to embodiment 24 or 25, wherein a sealing region (154) of the closure piston (152) is made of a metal having a lower hardness than a metal from which the sealing seat (148) is made, or vice versa. 27. Refrigerant compressor according to embodiment 25 or 26,wherein 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). 28. Refrigerant compressor according to one of embodiments 25 to 27, wherein the sealing seat (148) is arranged in a wall section (124) running above the valve plate (88) and above the inlet chamber (94). 29. Refrigerant compressor according to one of embodiments 25 to 28, wherein the sealing seat (148) is arranged on a side of the inlet chamber (94) opposite the valve plate (88). 30. Refrigerant compressor according to one of embodiments 25 to 29, wherein, starting from the sealing seat (148), a stroke of the closure piston (152) is in the range of one quarter to one half of an average diameter of the connecting channel (144). 31. Refrigerant compressor according to one of the preceding embodiments,wherein 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). 32. Refrigerant compressor according to one of the preceding embodiments, wherein the respective mechanical power control unit (142) is assigned to a cylinder bank (86). 33. Refrigerant compressor according to one of the preceding embodiments, wherein, in the case of N cylinder banks (86) of the refrigerant compressor, a mechanical power control unit (142) is assigned to at least N-1 cylinder banks (86). 34. Refrigerant compressor according to one of embodiments 31 to 33, wherein each cylinder bank (86) is assigned a mechanical power control unit (142). 35. Refrigerant compressor according to one of embodiments 24 to 34,wherein the closure piston (152) is biased by a compression spring (166) toward its position cooperating with the sealing seat (148). 36. Refrigerant compressor according to one of embodiments 24 to 35, wherein the closure piston (152) is actuated by a pressure chamber (162) which, depending on the external control of the power control unit (142), can be actuated either by suction pressure or by high pressure. 37. Refrigerant compressor according to embodiment 36, wherein the pressure chamber (162) in the open position of the closure piston (152) has a volume that is less than one-third, preferably less than one-quarter, of the maximum volume of the pressure chamber (162) in the closed position. 38. Refrigerant compressor according to one of the preceding embodiments, wherein a control unit (182) encompassed by the power control unit (142) is provided,with which the pressurization of the closure piston (152) can be controlled. 39. Refrigerant compressor according to one of the preceding embodiments, wherein a power control (138) is provided which controls the at least one mechanical power control unit (142) according to a required compressor delivery rate. 40. Cylinder head (92) for a refrigerant compressor, in particular a reciprocating piston compressor, for mounting on a valve plate (88) which closes off at least one cylinder bore (72, 74) and overlaps said bore with an open side (93), so that said valve plate delimits an inlet chamber (94) arranged between the valve plate (88) and the cylinder head (92) and an outlet chamber (96), wherein a mechanical power control unit (142) is provided, with which an inlet chamber (94) and an outlet chamber (96) can be connected to one another for power reduction.and that in the region of the cylinder head (92), a check valve (220) is provided which is held thereon, which allows a refrigerant flow escaping from the cylinder head (92) and blocks a refrigerant flow opposite to this escaping refrigerant flow. 41. Cylinder head according to embodiment 40, wherein the check valve (220) is arranged downstream of the outlet chamber (96) and prevents a backflow of refrigerant present downstream of the check valve (220) into the outlet chamber (96). 42. Cylinder head according to embodiment 40 or 41, wherein the check valve (220) is arranged at a distance from the open side (93) on the cylinder head (92). 43. Cylinder head according to one of the embodiments 40 to 42, wherein the check valve (220) is arranged on a region of the cylinder head (92) facing away from the open side (93). 44. Cylinder head according to one of the embodiments 40 to 43,wherein the check valve (220) is arranged in the region of a transition from the outlet chamber (96) into an outlet-side refrigerant path (210). 45. Cylinder head according to one of embodiments 40 to 44, wherein the check valve (220) is arranged and fixed in a receptacle (258) arranged on the cylinder head (92). 46. Cylinder head according to one of embodiments 40 to 45, wherein the receptacle (258) is integrally formed on the cylinder head (92). 47. Cylinder head according to one of embodiments 40 to 46, wherein the check valve (220) is arranged in a tightly sealed manner with the receptacle (258). 48. Cylinder head according to one of embodiments 40 to 47, wherein the check valve (220) has a valve body (222) with at least one passage opening (226) arranged therein, and wherein the passage opening (226) can be closed by a valve blade (234) movable relative to the valve body (222). 49. Cylinder head according to embodiment 48,wherein the valve plate (234) is spring-loaded in the direction of a flow-blocking position in which the valve plate (234) bears against a sealing surface (232) of the valve body (222). 50. Cylinder head according to embodiment 48 or 49, wherein the valve plate (234) is guided so as to be movable relative to the valve body (222). 51. Cylinder head according to embodiment 50, wherein the valve plate (234) is spaced apart from the valve body (222) as a whole in a flow-release position. 52. Cylinder head according to one of embodiments 48 to 51, wherein the check valve (220) has a catcher body (242) for the valve plate (234), which positions it in its flow-release position. 53. Cylinder head according to one of embodiments 48 to 52, wherein the valve body (222) is designed as an annular body. 54. Cylinder head according to embodiment 53,wherein the valve body (222) has at least one passage opening (226) arranged in an annular region around a central axis (224). 55. Cylinder head according to embodiment 54, wherein the valve plate (234) is designed as an annular body. 56. Cylinder head according to embodiment 55, wherein the valve plate (234), in its flow-release position, is surrounded by refrigerant flowing through the passage openings (226) both in the region of its inner edge (252) and in the region of its outer edge (254). 57. Cylinder head according to one of embodiments 40 to 56, wherein the mechanical power control unit (142) is arranged on the cylinder head (92), in particular wherein the mechanical power control unit (142) is at least partially integrated into the at least one cylinder head (92). 58. Cylinder head according to one of embodiments 40 to 57,wherein the mechanical power control unit (142) connects the outlet chamber (96) in the cylinder head (92) to the inlet chamber (94) in the cylinder head (92) by means of a controllable connecting channel (144) for power reduction, in particular that the connecting channel (144) is arranged integrated into the cylinder head (92). 59. Cylinder head according to one of the embodiments 40 to 58, characterized in that the mechanical power control unit (142) has a closure piston (152) for closing the connecting channel (144), in particular that the closure piston (152) for closing the connecting channel (144) can be placed on a sealing seat (148) which extends enclosing the connecting channel (144), in particular that a sealing region (154) of the closure piston (152) is made of a metal which has a lower hardness than a metal from which the sealing seat (148) is made or vice versa, in particular,that 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), in particular that the sealing seat (148) is arranged in a wall section (124) running above the valve plate (88) and above the inlet chamber (94), in particular that the sealing seat (148) is arranged on a side of the inlet chamber (94) opposite the valve plate (88). 60. Cylinder head according to one of embodiments 40 to 59, wherein a control unit (182) is provided which is comprised by the power control unit (142) and with which the pressurization of the closure piston (152) can be controlled. 61. Cylinder head according to one of embodiments 40 to 60, wherein a power control (138) is provided which controls the at least one mechanical power control unit (142) in accordance with a required compressor delivery rate.

[0088] Further features and advantages of the invention are the subject of the following description and the drawings of some embodiments. The drawing shows:

[0089] Fig. 1 is a side view of an embodiment of a refrigerant compressor according to the invention; Fig. 2 is a plan 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 embodiment of the refrigerant compressor according to the invention; Fig. 4 a half-offset section along line 4-4 in Fig. 2 ; Fig. 5a longitudinal section along line 5-5 in Fig. 2 through the refrigerant compressor according to the invention; Fig. 6 a section along line 6-6 in Fig. 7 ; Fig. 7 a section through a first embodiment of a cylinder head according to the invention along line 7-7 in Fig. 6 ; Fig. 8 an enlarged view of a check valve according to the invention in the closed position; Fig. 9 a view similar Fig. 8 of the check valve according to the invention in the open position; Fig. 10 a representation similar Fig. 7 a second embodiment of a cylinder head according to the invention; Fig. 11 a representation similar Fig. 7 a third embodiment of a cylinder head according to the invention and Fig. 12 a representation similar Fig. 7 a fourth embodiment of a cylinder head according to the invention.

[0090] An embodiment of a refrigerant compressor according to the invention, shown in Fig. 1 bis 5 , comprises an overall housing 10 in which a reciprocating piston compressor 12, in particular a compressor with pistons movable with a shaft axis, and an electric motor 14 are arranged.

[0091] Preferably, the overall housing 10 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.

[0092] The overall housing 10 is preferably formed by a one-piece housing body 26 which extends in a direction parallel to a central axis 28 which will be explained in more detail below and is closed at the end by a bearing cover 32 on the side of the compressor housing section 22 and is closed at the end by an end cover 34 in the region of the motor section 24.

[0093] 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, wherein the second shaft bearing 46 is held on a central wall 48 formed in the housing body 26, which delimits a drive chamber 52 lying between the bearing cover 32 and the central wall 48, through which the compressor shaft 42 extends and in which eccentrics 54 and 56 of the compressor shaft 42 are arranged, wherein on each of the eccentrics 54 and 56 a connecting rod 62 1 and 62 2 each with a connecting rod arm, or two connecting rods 64 1 and 64 2 each with a connecting rod arm, are arranged, wherein the connecting rod arms of the connecting rods 62 1 and 64 1 drive the pistons 66 1 and 68 1 and the connecting rod arms of the connecting rods 62 2 and 64 2 drive the pistons 66 2 and 68 2.

[0094] The pistons 66 and 68, which are driven and movable radially to the compressor shaft 42 in particular in the case of the compressor, are guided in cylinder bores 72 and 74 which are formed by cylinder housings 76, 78 which are molded into the compressor housing section 22, in particular molded in one piece.

[0095] Each cylinder housing 76, 78 with the cylinder bore 72, 74 and the piston 66, 68 guided in this bore forms a cylinder 82, 84.

[0096] The two first cylinders 82 1 and 84 1 formed in the compressor housing section 22 form a first cylinder bank 86 1 , while the two cylinders 82 2 and 84 2 formed in the compressor housing section 22 form a second cylinder bank 86 2 .

[0097] 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 rests tightly on the respective cylinder housings 76 1 and 78 1 or 76 2 and 78 2 by means of a seal 89 and thus delimits compression chambers enclosed by the respective valve plate 88 1 or 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 .

[0098] The valve plates 88 1 and 88 2 are in turn covered by cylinder heads 92 1 and 92 2 respectively, wherein the cylinder heads 92 1 and 92 2 respectively face the valve plates 88 1 and 88 2 with their open sides 93 1 , 93 2 , with these sitting tightly on the valve plates 88 1 , 88 2 .

[0099] In each of the cylinder heads 92 1 and 92 2, as shown in the Fig. 6 and 7 shown, an inlet chamber 94 encompassed by a suction side of the reciprocating compressor 12 and an outlet chamber 96 encompassed by a pressure side of the reciprocating compressor 12 are arranged, which are assigned to the two cylinders 82 and 84 of the respective cylinder bank 86.

[0100] In particular, the inlet chamber 94 is located above inlet openings 102 and 104 of the cylinder 82 arranged in the respective valve plate 88 and inlet openings 106 and 108 of the cylinder 84 of the respective cylinder bank 86, for example the cylinder bank 86 2, and is directly adjacent to the valve plate 88.

[0101] Furthermore, the outlet chamber 96 is located above outlet openings 112 and 114 of the cylinder 82 arranged in the respective valve plate 88, as well as outlet openings 116 and 118 of the cylinder 84, which are provided with outlet valves 113, 115, 117, 119 sitting on the valve plate 88, and in particular directly adjoins the valve plate 88.

[0102] As in Fig. 6 and 7 As shown, each cylinder head 92 comprises an outer body 122, which is supported on the respective valve plate 88 via a sealing layer 123 and engages over it 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 and connected to it, wherein the outer body 122 and the separating body 124 rise from the respective valve plate 88 and extend over the inlet chamber 94 and the outlet chamber 96 and overlap them.

[0103] Thus, the outlet chamber 96 is located in the region of the valve plate 88 laterally next to the inlet chamber 94 and extends between the outer body 122 and the separating body 124, at least in part, also over the inlet chamber 94.

[0104] To control the power, i.e. to control the compressor delivery capacity, of the refrigerant compressor, each cylinder head 92 can be 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 can be closed or opened, wherein the respective cylinders 82, 84 assigned to the cylinder head 92, when the connecting channel 144 is closed ( Fig. 7 ) compress refrigerant at full power and compress no refrigerant when the connecting channel 144 is open, since the refrigerant flows back through the connecting channel 144 from the outlet chamber 96 into the inlet chamber 94.

[0105] The connecting channel 144 runs with a section 144a through an insert part 146 inserted into the separating body 124, which insert part forms a sealing seat 148 facing the outlet chamber 96 and which adjoins a part of the outlet chamber 96 surrounding the sealing seat 148 and adjoining it.

[0106] Furthermore, the sealing seat 148 faces a closure piston 152, which can be placed onto the sealing seat 148, for example with a metallically formed sealing region 154, in order to tightly close the connecting channel 144, and which can be lifted away from the sealing seat 148 to such an extent that the sealing region 154 is spaced from the sealing seat 148 and thus refrigerant can flow through the section 144b from the outlet chamber 96 and the section 144a into the inlet chamber 94.

[0107] Preferably, the closure piston 152 is guided coaxially to the insert part 146 with the sealing 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 integrally formed on the outer body 122.

[0108] Preferably, the closure piston 152 itself or at least the sealing region 154 is made of a metal, for example a non-ferrous metal, which has a lower hardness than the metal of the sealing seat 148, which is made of steel, in particular hardened steel, for example.

[0109] In order to enable a rapid movement of the closure piston 152, in particular a stroke of the closure piston 152 lies between a closure position ( Fig. 7 ) and one in Fig. 7 open position indicated by dashed lines in the range between a quarter and a half of the average diameter of the connecting channel 144.

[0110] 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 on a side opposite the closure piston 152 by a closing body 164.

[0111] The volume of the pressure chamber 162 is in particular so small that in the open position of the closure piston it is less than one third, preferably less than one quarter, even better less than one fifth, advantageously less than one sixth and even more advantageously less than one eighth of the maximum volume of the pressure chamber 162 in the closed position of the closure piston 152.

[0112] Furthermore, a compression spring 166 is arranged in the pressure chamber 162, which on the one hand is supported on the closing body 164 and on the other hand acts on the closing piston 152 in the direction of its closing position resting on the sealing seat 148.

[0113] Depending on the pressure applied to the pressure chamber 162, the closure piston 152 is in its Fig. 7 open position shown in dashed lines or in its Fig. 7 shown locking position movable.

[0114] 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 an orifice opening 157 which is arranged radially outside the sealing region 154 on a side facing the sealing seat 148, but because it lies radially outside the sealing element 154, in the closed position of the closure piston 152, allows the entry of refrigerant which is under pressure in the outlet chamber 96 and flows around the sealing seat and supplies this in a throttled manner to the pressure chamber 162.

[0115] In addition, a relief channel 176 leads into the pressure chamber 162, for example through the closing body 164, which can be connected by a solenoid valve designated as a whole by 182 to a pressure relief channel 184 which is connected to the inlet chamber 94.

[0116] For example, the solenoid valve 182 is designed to have a valve body 186 with which the connection between the pressure relief channel 184 and the relief channel 176 can be interrupted or established.

[0117] 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.

[0118] 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, in addition, high pressure flows through the throttle channel 172 into the pressure chamber 162, so that high pressure builds up in the pressure chamber 162, which, in addition to the effect of the compression spring 166, presses the closure piston 152 with the sealing element 154 onto the sealing seat 148.

[0119] In particular, the closure piston 152 is designed in such a way that it extends radially beyond the sealing seat 148, so that even when the closure piston 152 is in the closed position, the piston surface located radially outside the sealing seat 148 and subjected to high pressure causes the closure piston 152 to move against the force of the compression spring 166 into the open position, shown in dashed lines in Fig. 7 , is moved, provided that the valve body 186 of the solenoid valve 182 establishes the connection between the relief channel 176 and the pressure relief channel 184, which leads to a suction pressure being established in the pressure chamber 162.

[0120] The supply of refrigerant under suction pressure takes place via a supply channel 202 ( Fig. 5 ), which leads to an inlet opening 204 leading to the valve plate 88 ( Fig. 7 ), through which refrigerant under suction pressure flows to a passage opening 206 in the valve plate 88 and passes through this into the inlet chamber 94.

[0121] In addition, as in Fig. 7 shown, an outlet channel 210 formed in the cylinder head 92 and encompassed by the pressure side of the reciprocating compressor 12 from 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 a pressure connection 216.

[0122] At the transition from the outlet chamber 96 to the outlet channel 210, a check valve designated as a whole by 220 is provided, which, as in Fig. 8 and 9 shown enlarged, has a valve body 222 which is designed, for example, as an annular body and has, in an annular region around a central axis 224, successively arranged passage openings 226 which pass through the valve body 222 starting from an inflow side 228 to an outflow side 232.

[0123] A valve blade 234, which is also designed as an annular body, is provided to be movable relative to the valve body 222 and which can be placed tightly against the downstream side 232 of the valve body 222 to close the passage openings 226 and can be moved away from the downstream side 232 as a whole and positioned at a distance from the downstream side 232 to open the passage openings 226.

[0124] This position of the valve lamella 234 blocking the flow 226 through the check valve 220 from the downstream side 232 in the direction of the upstream side 228 is effected by a spring element 236, which is also designed as an annular body and which is supported on the one hand on a side of the valve lamella 234 opposite the downstream side 232 and on the other hand is supported on a catcher body 242 of the check valve 220, which is held at a distance from the downstream side 232, for example on a central region 244 of the valve body 222 lying between the passage openings 226 and the central axis 224, wherein the central region 244 extends around the central axis 224 and within the passage openings 226.

[0125] Preferably, a retaining pin 246 is anchored in the central region 244, which pin passes through central openings of both the valve blade 234 and the spring element 236 and extends to the catcher body 242 and is firmly connected thereto, so that the retaining pin 246 fixes the catcher body 242 in the direction of the central axis 224 so as to be non-displaceable relative to the valve body 222 against movements in the direction of the central axis 224.

[0126] In the Fig. 9 In the maximum open position shown, the valve blade 234, which has been moved as a whole away from the downstream side 232, allows flow through each of the respective passage openings 226 from the upstream side 228 in the direction of the downstream side 232, wherein the flow then exits from the respective passage opening 226 on the downstream side 232 and flows radially outwards and radially inwards in the direction of the holding pin 246 with respect to the central axis 224, in order to flow past both an inner edge 252 and an outer edge 254 of the valve blade 234 as well as an outer side of the spring element 236 and the catcher body 242 and through openings 248 arranged around the holding pin 246 in the catcher body 242.

[0127] Preferably, the valve body 222 is designed as an annular body, i.e. rotationally symmetrical to the central axis 224, and has a circular cylindrical outer surface 255, with which it is inserted into a receptacle 258, formed at the transition from the outlet chamber 96 into the outlet channel 210, and is fixed, for example, on the one hand by an arranged collar 256 and on the other hand by a retaining ring 257, and thereby tightly seals with the receptacle 258.

[0128] Alternatively, the outer surface 255 may be provided with a thread and screwed into a thread of the receptacle 258.

[0129] If a lower pressure than high pressure is present in the outlet chamber 96, for example in the event of a pressure drop caused by the power control 138 by means of the power control unit 142, the valve blade 234 closes the passage openings 226 due to the action of the spring element 236, so that the pressure in the outlet channel 210 is maintained, and a pressure equalization between the outlet chamber 96 and the inlet chamber 94 due to the action of the mechanical power control unit 142 does not affect the pressure in the outlet channel 210.

[0130] By arranging the check valve 220 in the respective cylinder head 92, it is thus possible to easily convert a conventional, for example non-power-controlled compressor into a power-controllable cylinder head 92 by replacing the cylinder head 92 with the power control unit 142 and the check valve 220, without requiring changes in the design of the respective valve plate 88 and the respective cylinder bank 86.

[0131] In a second embodiment of a refrigerant compressor according to the invention with a second embodiment of a cylinder head 92' according to the invention, those elements which are identical to those of the first embodiment are provided with the same reference numerals, so that reference can be made in full to the explanations relating to the first embodiment.

[0132] In contrast to the first embodiment, the outlet channel 210' in the cylinder head 92' is designed such that it leads directly to a pressure connection 260' provided on the cylinder head 92', which, for example, is led from a side opposite the valve plate 88 to the outer body 122 and is directly connected thereto, so that the outlet channel 210' merges directly into a pressure line of the pressure connection 260'.

[0133] In this case, the receptacle 258' for the valve body 222 is provided in the cylinder head 92' in a receptacle body 262 projecting into the outlet chamber 96 from a side opposite the valve plate 88, wherein the receptacle body 262 is preferably also formed integrally with the outer body 122 of the cylinder head 92'.

[0134] In a third embodiment of a refrigerant compressor according to the invention with a third embodiment of a cylinder head 92", shown in Fig. 11 , the check valve 220 is arranged such that the valve body 222 sits in a receptacle 258" which is formed directly in an outer wall of the outer body 122 of the cylinder head 92", so that no additional measures are required to accommodate the check valve 220 in the cylinder head 92", but only a passage is provided in the outer wall of the outer body 122, which forms the receptacle 258" for the valve body 222, wherein, for example, the valve body 222 is screwed with an external thread into an internal thread of the receptacle 258".

[0135] In this case, the pressure connection 260" can be easily mounted on the outer body 122 so that the refrigerant passing through the check valve 220 can enter directly into the pressure line of the pressure connection 260".

[0136] Furthermore, in the third embodiment, those elements which are identical to the preceding embodiments are provided with the same reference numerals, so that with regard to the description thereof, reference can be made in full to the statements relating to the preceding embodiments.

[0137] In a fourth embodiment of a refrigerant compressor according to the invention with a fourth embodiment of a cylinder head 92‴, those elements which are identical to those of the preceding embodiments are provided with the same reference numerals, so that with regard to the description thereof, reference can be made in full to the statements relating to the preceding embodiments.

[0138] In contrast to the preceding embodiments, in the fourth embodiment, a passage 264 is provided in the outer body 122 of the cylinder head 92‴, from which passage refrigerant can enter directly into a pressure connection 260‴, wherein the check valve 220 is inserted into a receptacle 258‴ ​​arranged on the inlet side of the pressure connection 260‴, so that the pressure connection 260‴ itself forms the receptacle 258‴ ​​for the valve body 222.

[0139] For example, the pressure connection 260‴ can be part of a shut-off valve 266 mounted on the cylinder head 92‴.

[0140] Thus, in the fourth embodiment of the refrigerant compressor according to the invention, the check valve 220 is not accommodated in the cylinder head 92‴, but is held indirectly on the cylinder head 92‴ via the high-pressure connection 260.

[0141] The embodiments of the refrigerant compressors according to the invention are designed, for example, as semi-hermetic compressors, so that refrigerant under suction pressure is supplied to a motor compartment 274 by means of an inlet connection element 272 arranged on the end cover 34 and flows through the electric motor 14 in the direction of the center wall 48 and passes from the motor compartment 274 into the supply channel 202, so that the supplied suction-side refrigerant cools the electric motor 14 in the motor compartment 274.

[0142] The electric motor 14 in turn comprises a stator 282 with a stator winding 284, which is fixedly held in the motor housing section 24.

[0143] The stator 282 further comprises a rotor 286, which comprises, for example, permanent magnets and can be operated as a synchronous motor and additionally a squirrel cage so that it can start as an asynchronous motor.

Claims

1. Refrigerant compressor, comprising a reciprocating piston compressor (12) and an electric motor (14), an overall housing (10) which has a motor housing section (24) for the electric motor (14) and a compressor housing section (22) for the reciprocating piston compressor (12), a suction connection (272) connected to a suction side of the reciprocating piston compressor (12) and a pressure connection (216, 260', 260", 260"') connected to a pressure side of the reciprocating piston compressor (12), wherein at least one cylinder (82, 84) of the reciprocating piston compressor (12) is provided in the compressor housing section (22), which cylinder has a piston (66, 68) movable in a cylinder bore (72, 74) formed in the compressor housing section (22) and a valve plate (88) closing the cylinder bore (72, 74) and a valve plate (88) and forming part of the compressor housing section (22), characterized in thata mechanical power control unit (142) is provided, with which the suction side and the pressure side can be connected to one another in order to reduce the power, and that in the region of the cylinder head (92) a check valve (220) is provided which is held thereon and which allows a refrigerant flow emerging from the cylinder head (92) and blocks a refrigerant flow opposite to this refrigerant flow.

2. Refrigerant compressor according to claim 1, characterized in that the check valve (220) is arranged following the outlet chamber (96) and prevents a backflow of refrigerant present following the check valve (220) into the outlet chamber (96).

3. Refrigerant compressor according to claim 1 or 2, characterized in that the check valve (220) is arranged at a distance from the valve plate (88) on the cylinder head (92).

4. Refrigerant compressor according to one of the preceding claims, characterized in thatthe check valve (220) is arranged on a region of the cylinder head (92) facing away from the valve plate (88) 5. Refrigerant compressor according to one of the preceding claims, characterized in that the check valve (220) is arranged in the region of a transition from the outlet chamber (96) into an outlet-side refrigerant path (210).

6. Refrigerant compressor according to one of the preceding claims, characterized in that the check valve (220) is arranged and fixed in a receptacle (258) arranged on the cylinder head (92).

7. Refrigerant compressor according to one of the preceding claims, characterized in that the holder (258) is formed onto the cylinder head (92).

8. Refrigerant compressor according to one of the preceding claims, characterized in that the check valve (220) is arranged in a tightly sealed manner with the receptacle (258).

9. Refrigerant compressor according to one of the preceding claims, characterized in thatthe check valve (220) has a valve body (222) with at least one passage opening (226) arranged therein, and in that the passage opening (226) can be closed by a valve blade (234) that is movable relative to the valve body (222), in particular in that the valve blade (234) is spring-loaded in the direction of a flow-blocking position in which the valve blade (234) rests against a sealing surface (232) of the valve body (222), and / or in particular in that the valve blade (234) is guided so as to be movable relative to the valve body (222), and / or in particular in that the valve blade (234) is spaced apart from the valve body (222) as a whole in a flow-release position, and / or in particular in that the check valve (220) has a catcher body (242) for the valve blade (234), which positions it in its flow-release position and / or that in particular the valve body (222) is designed as an annular body,in particular that the valve body (222) has at least one passage opening (226) arranged in an annular region around a central axis (224), in particular that the valve lamella (234) is designed as an annular body, in particular that the valve lamella (234) in its flow-release position is surrounded by refrigerant flowing through the passage openings (226) both in the region of its inner edge (252) and in the region of its outer edge (254).

10. Refrigerant compressor according to one of the preceding claims, characterized in that the mechanical power control unit (142) is arranged on the at least one cylinder head (92), in particular that the mechanical power control unit (142) is at least partially integrated into the at least one cylinder head (92).

11. Refrigerant compressor according to one of the preceding claims, characterized in thatthe 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 controllable connecting channel (144) for power reduction, in particular that the connecting channel (144) is arranged integrated into the cylinder head (92).

12. Refrigerant compressor according to one of the preceding claims, characterized in that an outlet chamber (96) in the cylinder head (92) is arranged immediately adjacent to at least one outlet opening (112, 114, 116, 118) for the respective cylinder (82, 84) in the valve plate (88).

13. Refrigerant compressor according to one of the preceding claims, characterized in that an 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).

14. Refrigerant compressor according to one of the preceding claims, characterized in thatthe mechanical power control unit (142) has a closure piston (152) for closing the connecting channel (144), in particular that the closure piston (152) for closing the connecting channel (144) can be placed on a sealing seat (148) which extends enclosing the connecting channel (144), in particular that a sealing region (154) of the closure piston (152) is made of a metal which has a lower hardness than a metal from which the sealing seat (148) is made or vice versa, in particular that 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), in particular that the sealing seat (148) is arranged in a wall section (124) running above the valve plate (88) and above the inlet chamber (94), in particular,that the sealing seat (148) is arranged on a side of the inlet chamber (94) opposite the valve plate (88).

15. 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).

16. 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).

17. Refrigerant compressor according to one of the preceding claims, characterized in that in the case of N cylinder banks (86) of the refrigerant compressor, a mechanical power control unit (142) is assigned to at least N-1 cylinder banks (86).

18. Refrigerant compressor according to one of claims 15 to 17, characterized in that each cylinder bank (86) is assigned a mechanical power control unit (142).

19. Refrigerant compressor according to one of claims 14 to 18, characterized in that the closure piston (152) is urged by a compression spring (166) in the direction of its position cooperating with the sealing seat (148).

20. Refrigerant compressor according to one of claims 14 to 19, characterized in that the closure piston (152) can be actuated by a pressure chamber (162) which can be actuated either by suction pressure or by high pressure depending on the external control of the power control unit (142).

21. Refrigerant compressor according to one of the preceding claims, characterized in that a control unit (182) is provided which is comprised by the power control unit (142) and with which the pressurization of the closure piston (152) can be controlled.

22. Refrigerant compressor according to one of the preceding claims, characterized in thata power control (138) is provided which controls the at least one mechanical power control unit (142) in accordance with a required compressor delivery rate.

23. Cylinder head (92) for a refrigerant compressor, in particular a reciprocating piston compressor, for mounting on a valve plate (88) closing at least one cylinder bore (72, 74) and overlapping said bore with an open side (93), so that said valve plate delimits an inlet chamber (94) and an outlet chamber (96) arranged between the valve plate (88) and the cylinder head (92), characterized in thata mechanical power control unit (142) is provided, with which an inlet chamber (94) and an outlet chamber (96) can be connected to one another for power reduction, and in that in the region of the cylinder head (92) a check valve (220) is provided which is held thereon and which allows a refrigerant flow emerging from the cylinder head (92) and blocks a refrigerant flow opposite to this refrigerant flow emerging.

24. Cylinder head according to claim 23, characterized in that the check valve (220) is arranged at a distance from the open side (93) on the cylinder head (92).

25. Cylinder head according to one of claims 23 or 24, characterized in that the check valve (220) is arranged on a region of the cylinder head (92) facing away from the open side (93) 26. Cylinder head according to one of claims 23 to 25, characterized in thatthis is designed according to one or more of the features of the cylinder head mentioned in connection with the refrigerant compressor according to the preceding claims 2 and / or 5 to 16 and / or 19 to 22.

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