MULTISTAGE COMPRESSOR

Abstract

A multistage compressor may have at least one high-pressure stage and at least one low-pressure stage. The compressor may also include at least two pistons, which are driven via a common crankshaft supported in a crankcase, and which may be guided in associated cylinders, and which may form the at least one high-pressure stage and the at least one low-pressure stage. The compressor may further include a line arrangement which may communicate with the each of the cylinders for supplying and discharging air to and from the cylinders. There may be arranged in the line arrangement a switchable valve, which may be constructed in such a manner that the at least one high-pressure stage depending on a switching position of the valve may be associated with a different one of the cylinders.

Claims

1. A multistage condenser, comprising: at least one high-pressure stage and at least one low-pressure stage; at least two pistons which are driven via a common crankshaft supported in a crankcase, and which are guided in associated cylinders, and which form the at least one high-pressure stage and the at least one low-pressure stage; a line arrangement which communicates with the each of the cylinders for supplying and discharging air to and from the cylinders; wherein there is arranged in the line arrangement a switchable valve, which is constructed in such a manner that the at least one high-pressure stage depending on a switching position of the valve device is associated with a different one of the cylinders.

2. The condenser as claimed in claim 1, wherein the at least one high-pressure stage for each cylinder operating cycle or each switching position moves one cylinder further.

3. The condenser as claimed in claim 1, wherein, during a time range, each of the pistons and associated cylinders being constructed for a same number of cylinder operating cycles as a high-pressure stage or as a low-pressure stage.

4. The condenser as claimed in claim 1, further comprising a pre-compression cooler arranged downstream of the at least one low-pressure stage and upstream of the at least one high-pressure stage.

5. The condenser as claimed in claim 1, wherein the valve has a rotatable cylindrical valve body.

6. The condenser as claimed in claim 1, wherein the valve device is one of pneumatically, electrically or hydraulically switchable.

7. The condenser as claimed in claim 1, wherein: the at least one high-pressure stage includes one high-pressure stage and the at least one low-pressure stage includes three low-pressure stages; and the at least two pistons include four pistons to form the one high-pressure stage and the three low-pressure stages.

8. A compressor comprising a multistage condenser having: at least one high-pressure stage and at least one low-pressure stage; at least two pistons, which are driven via a common crankshaft supported in a crankcase, and which are guided in associated cylinders, and which form the at least one high-pressure stage and the at least one low-pressure stage; a line arrangement which communicates with the each of the cylinders for supplying and discharging air to and from the cylinders; wherein there is arranged in the line arrangement a switchable valve, which is constructed in such a manner that the at least one high-pressure stage depending on a switching position of the valve is associated with a different one of the cylinders.

9. An operating method of a multistage condenser having at least one high-pressure stage and at least one low-pressure stage, at least two pistons driven by a common crankshaft supported in a crankcase and guided in associated cylinders to form the at least one high-pressure stage and the at least one low-pressure stage, and a line arrangement communicating with each of the cylinders for supplying and discharging air to and from the cylinders, the method comprising: switching a valve of the multistage condenser into a position in which at least one high-pressure stage of the multistage condenser is associated with one of at least two cylinders such that the at least one high-pressure stage moves the one of at least two cylinders further for each cylinder operating cycle.

10. The condenser as claimed in claim 2, wherein, during a time range, each of the pistons and associated cylinders being constructed for a same number of cylinder operating cycles as a high-pressure stage or as a low-pressure stage.

11. The condenser as claimed in claim 2, further comprising a pre-compression cooler arranged downstream of the at least one low-pressure stage and upstream of the at least one high-pressure stage.

12. The condenser as claimed in claim 2, wherein the valve has a rotatable cylindrical valve body.

13. The condenser as claimed in claim 2, wherein the valve device is one of pneumatically, electrically or hydraulically switchable.

14. The condenser as claimed in claim 2, wherein: the at least one high-pressure stage includes one high-pressure stage and the at least one low-pressure stage includes three low-pressure stages; and the at least two pistons include four pistons to form the one high-pressure stage and the three low-pressure stages.

15. The compressor as claimed in claim 8, wherein the at least one high-pressure stage for each cylinder operating cycle or each switching position moves one cylinder further.

16. The compressor as claimed in claim 8, wherein, during a time range, each of the pistons and associated cylinders being constructed for a same number of cylinder operating cycles as a high-pressure stage or as a low-pressure stage.

17. The compressor as claimed in claim 8, further comprising a pre-compression cooler arranged downstream of the at least one low-pressure stage and upstream of the at least one high-pressure stage.

18. The compressor as claimed in claim 8, wherein the valve has a rotatable cylindrical valve body.

19. The compressor as claimed in claim 8, wherein the valve device is one of pneumatically, electrically or hydraulically switchable.

20. The compressor as claimed in claim 8, wherein: the at least one high-pressure stage includes one high-pressure stage and the at least one low-pressure stage includes three low-pressure stages; and the at least two pistons include four pistons to form the one high-pressure stage and the three low-pressure stages.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the schematic drawings:

[0018] FIG. 1 is a sectioned illustration through a multistage condenser according to the invention without a more detailed illustration of an associated valve device according to the invention,

[0019] FIG. 2 shows an associated valve device in a first switching position,

[0020] FIG. 3 is an illustration as in FIG. 2, with a valve device in a second switching position,

[0021] FIG. 4 shows a possible embodiment of a valve member of the valve device,

[0022] FIG. 5 shows an upper portion of the valve member in the intake cycle,

[0023] FIG. 6 shows a lower portion of the valve member in the exhaust cycle.

DETAILED DESCRIPTION

[0024] According to FIGS. 1 to 3, a multistage condenser 1 according to the invention has at least one high-pressure stage 2 and at least one low-pressure stage 3. According to FIG. 2, the multistage condenser 1 has a total of four pressure stages, of which one is constructed as a high-pressure stage 2 and three are constructed as low-pressure stages 3. Each pressure stage 2, 3 has in this instance an individual piston/cylinder unit 4 having a cylinder 5 and a piston 6 which is supported therein so as to be able to be adjusted in a translational manner, wherein the pistons 6 are driven by means of a common crankshaft 8 which is supported in a crankcase 7 (cf. FIG. 1). There is also provided a line arrangement 9 which communicates with the individual cylinders 5 for supplying and discharging air to and from the cylinders 5. In the line arrangement 9 (cf. in particular FIGS. 2 and 3) there is arranged according to the invention a switchable valve device 10 which is constructed in such a manner that the high-pressure stage 2 depending on the switching position of a valve member 11 of the valve device 10 is or becomes associated with different cylinders 5, in particular in such a manner that the at least one high-pressure stage 2 during each operating cycle of a piston 6 moves one cylinder 5 further. Alternatively, it is also conceivable to change the high-pressure stage 2 not for each operating cycle, but instead, for example, only for each tenth operating cycle. That is to say, over a time range t, all the piston/cylinder units 4 would still be loaded and therefore also worn in the same manner.

[0025] According to FIG. 2, in this instance, the valve device 10 is shown in an intake position in which the low-pressure stages 3 draw air from the crankcase 7 via the valve body 11 of the valve device 10. The intake can selectively also be carried out directly from the ambient air or an intermediate filter. In the same manner, air which has already been pre-compressed in a previous operating cycle and which is cooled via the pre-compressor cooler 12 is drawn and supplied via the valve body 11 of the valve device 10 of the high-pressure stage 2, that is to say, therefore, supplied to the piston/cylinder unit 4 which is depicted at the top left. In a next operating cycle, in the event of a consequently subsequent rotation of the valve body 11 of the valve device 10 in a clockwise direction, the high-pressure stage 2 would move from the top left to the top right and in the same manner the low-pressure stages 3 would be rotated about a piston/cylinder unit 4 in each case in a clockwise or counter-clockwise direction. Of course, other movements of the valve body 11 are also conceivable, for example, translational ones.

[0026] If FIG. 3 is viewed, it is possible to see an exhaust cycle, in which the pre-compressed air from the three low-pressure stages 3 is directed via the valve body 11 of the valve device 10 to the first pre-compression cooler 12. In the same manner, in the high-pressure stage 2 highly compressed charging air is supplied via the valve body 11 of the valve device 10, for example, to a second high-compression cooler 13 and/or finally to a pressure store 14. By rotating the valve body 11 in the clockwise direction or in the opposite direction, using the valve device 10 according to the invention and the associated line arrangement 9, a movement of the respective high-pressure stage 2 via the individual piston/cylinder units 4 is achieved, whereby the occurrences of wear which increasingly appear in the high-pressure stage 2 can be distributed in a uniform manner over all the piston/cylinder units 4 and whereby the service life of the multistage condenser 1 according to the invention is significantly increased.

[0027] According to FIG. 2, in this instance, for reasons of clarity, only the inlet lines of the line arrangement 9 in the respective piston/cylinder units 4 are illustrated, whilst, according to FIG. 3, only the outlet lines are illustrated. Of course, however, the line arrangement 9 still has an inlet and outlet line to and from the respective piston/cylinder unit 4.

[0028] In the condenser 1 illustrated in FIGS. 2 and 3, on the whole in each case three low-pressure stages 3 and in each case only a single high-pressure stage 2 are provided, wherein of course other low-pressure stages 3 or high-pressure stages 2 may also further be provided.

[0029] The multistage condenser 1 according to the invention is operated by the switchable valve device 10 being switched in such a manner that the high-pressure stage 2 depending on the switching position is associated with different cylinders 5, that is to say, different piston/cylinder units 4, so that the at least one high-pressure stage 2 for each operating cycle of the piston 6 or for each switching cycle of the valve device 10 moves one cylinder 5 or one piston/cylinder unit 4 further. Alternatively, it is also conceivable to change the high-pressure stage 2 not for every operating cycle but instead, for example, only for every tenth operating cycle. That is to say, over a time range t, all the piston/cylinder units 4 would still be loaded in the same manner and the increased occurrences of wear brought about by the high-pressure stage 2 can be transferred uniformly to all the piston/cylinder units 4. The multistage condenser 1 according to the invention further has the significant advantage that, for example, as a result of the failure of a single low-pressure stage 3, they can be switched off by identification, for example, by means of a corresponding control device so that the multistage condenser 1 according to the invention continues to operate even in the event of a failure of a single or a plurality of low-pressure stages 3 or high-pressure stages 2 since the high-pressure stage 2 is connected not only to a single but instead at least to fixed piston/cylinder units 4.

[0030] The valve device 10 has according to FIG. 4 a rotatable cylindrical valve body 11 having an upper portion 17 and a lower portion 18 and may be able to be switched pneumatically, electrically or hydraulically. In this instance, there are arranged in the valve body 11, on the covering face thereof, different inlets 15 or outlets 16 which depending on the switching position can also change their inlet function or outlet function. Of course, the inlets 15 and outlets 16 may also be arranged in a transposed manner.

[0031] According to FIG. 5, in this instance an upper portion 17 of the valve body 11 is shown in an intake position in which the low-pressure stages 3 draw air from the crankcase 7 or from the environment, in particular via a filter device. In this instance, an intake of air is carried out via three inputs 15a. The drawn air is in this instance supplied via the outputs 16a which are associated with the inputs 15a to the piston/cylinder units 4 which are constructed as low-pressure stages 3 and after the compression cycle is supplied to the pre-compression cooler 12. The term pre-compression cooler 12 in this instance refers to the cooling after the low-pressure compression and before the high-pressure compression. In the same manner, air which has already been pre-compressed in a previous operating cycle and cooled via the pre-compression cooler 12 is drawn via the inlet 15b and supplied via the valve body 11 of the valve device 10 and the outlet 16b associated with the inlet 15b to the high-pressure stage 2, that is to say, therefore, the piston/cylinder unit 4 which is depicted at the top left.

[0032] If FIG. 6 is viewed, it is possible to see at that location a lower portion 18 of the valve body 11 during an exhaust cycle which is carried out at the same time as the intake cycle of the upper portion 17 and in which the now pre-compressed air from the three low-pressure stages 3 is directed via the inlets 15a and the associated outlets 16a of the valve body 11 of the valve device 10 to the first pre-compression cooler 12. In the same manner, charge air which has been highly compressed in the high-pressure stage 2 is supplied via the inlet 15b of the valve body 11 of the valve device 10 and the associated outlet 16b, for example, to a second high-compression cooler 13 and/or finally to a pressure store 14. By rotating the valve body 11 in a clockwise direction or in the opposite direction, using the valve device 10 according to the invention and the associated line arrangement 9, a movement of the respective high-pressure stage 2 via the individual piston/cylinder units 4 is achieved, whereby the occurrences of wear which increasingly appear in the high-pressure stage 2 can be distributed in a uniform manner over all the piston/cylinder units 4 and whereby the service life of the multistage condenser 1 according to the invention significantly increases.

[0033] The two portions 17, 18 can be rotated relative to each other or together. The intake cycle is controlled via the lower portion 17. The exhaust cycle is controlled via the upper portion 18 or vice versa. Both portions 17, 18 move simultaneously in a clockwise or anti-clockwise direction in order to enable precise timing with at the same time a robust construction. However, there is no connection of the channels or millings between the upper portion 17 and the lower portion 18.

[0034] The crankshaft 8 and consequently the multistage condenser 1 can be driven, for example, by means of an electric motor which is not shown.