EP3601797A1

EP3601797A1 - Piston compressor with enlarged regulating region

Info

Publication number: EP3601797A1
Application number: EP17712994.7A
Authority: EP
Inventors: Thomas Kipp; Fedor Assonov; Michael Winkler
Original assignee: Knorr Bremse Systeme fuer Schienenfahrzeuge GmbH
Current assignee: Knorr Bremse Systeme fuer Schienenfahrzeuge GmbH
Priority date: 2016-03-21
Filing date: 2017-03-23
Publication date: 2020-02-05
Anticipated expiration: 2037-03-23
Also published as: JP2019510919A; CN109072897A; JP6771579B2; US20190048865A1; US11041490B2; EP3601797B1; KR20210107704A; RU2703046C1; WO2017186415A8; CN109072897B; DE102016105145A1; KR102275455B1; KR102353258B1; WO2017186415A1; KR20190123665A

Abstract

The invention relates to a piston compressor comprising at least one cylinder for compressing air with a piston arranged such that it can move therein in a compression chamber arranged above the piston in the cylinder. The compression chamber is connected to an inlet arrangement for air to be compressed and to an outlet arrangement for compressed air, the piston compressor being drivable by a first drive device. The inlet arrangement comprises a pre-compression device that can be driven by a second drive device with variable power and is used to increase the suction pressure at the air inlet.

Description

DESCRIPTION

The invention relates to a piston compressor with at least one cylinder for compressing air with a piston arranged therein movable in a above the piston in the cylinder compression space arranged with a

Inlet assembly for air to be compressed and connected to a compressed air outlet arrangement.

Piston compressors such as in particular oil-free piston compressors for

Rail vehicles are used for filling compressed air tanks, which compressed air is removed in particular at irregular intervals. The reciprocating compressors are usually sized for the replenishment, in which a

Pressure vessel is to be filled quickly, which is why a maximum flow is provided. For normal operation, in which, under certain circumstances, the compressor is operated rather briefly after longer exposure times and only for topping up removed compressed air, operation at maximum means

Volume flow a rather unfavorable operating condition, which could be avoided in a demand-based control of the delivery of such reciprocating compressors.

The controllability of known reciprocating compressors is limited by design-related maximum and minimum speeds. Thus, the upper speed limit of particular oil-free, dry-running piston compressors by the maximum

Limited relative speed of dry sliding couples. At low speeds, however, vibrations caused by free mass forces in

Piston compressor, which also reduces the lower speed when operating a

Piston compressor is limited. This results in only a small amount

Speed variability of reciprocating compressors, which in most applications requires compressed air delivery in intermittent operation.

In known reciprocating compressors Aussetzregelung the compressed air delivery is realized by the fact that the compressor is switched to a standstill, as soon as the System pressure reaches the switch-off pressure. If the system pressure then drops to the switch-on pressure, in particular by removing compressed air, the piston compressor is switched to the load run, in which it supplies a maximum volume flow at rated speed. Unless the compressed air tank or the compressed air system at the same time larger amounts of compressed air are removed, fills the

Compressed air tank relatively quickly, so that the piston compressor is switched off after a short turn-on again for a long time. The control spectrum of this known solution is thus limited to standstill and load and due to the associated respective cold start and higher wear and longer life of the reciprocating compressor unfavorable and even unsuitable for certain conditions of use.

In an alternative embodiment of a reciprocating compressor intermittent operation is realized with different predefined speeds, for example via a

Switching the motor between four and six poles or via an inverter, which can be switched between 50 Hz and 60 Hz. However, only a relatively limited control range can be realized by the specified engine speeds at the respective compressor. High engine speeds also cause a strong thermal load in particular of oil-free bearings, whereby the life of a reciprocating compressor significantly decreases. Although the solution is a simple approach to controlling the flow rate, the control spectrum is limited by the fixed engine speeds and under certain conditions of use can not be generated by the switching sufficient volume flow. German patent applications DE 10 2013 1 13 555 and DE 10 2013 1 13 556 each disclose a compressor system and a method for operating the compressor system as a function of the operating state of a

Rail vehicle or depending on the current situation of a

Rail vehicle known in which an actuator for continuous

Influencing the speed of the electric drive device of

Piston compressor is arranged, wherein the actuation of the actuator takes place via a control device. The actuator allows the operation of the

Drive device and thus the reciprocating compressor by different Speeds to the current operating state or to the current situation of the

Rail vehicle adapt.

The invention is therefore based on the object to provide an improved piston compressor with a larger control range of delivery performance with improvement of energy efficiency and power density available.

To solve this problem, a reciprocating compressor according to claim 1 and a method for controlling such a reciprocating compressor according to claim 6 is proposed. Further developments of the proposed solutions are the subject of the respective dependent claims.

To achieve the object, a piston compressor is proposed with at least one cylinder for compressing air with a piston arranged therein movable in a compression space arranged above the piston in the cylinder. The compression chamber has an air inlet and an air outlet and is on

Air inlet connected to an inlet assembly for compressed air and is connected at the air outlet with a compressed air outlet arrangement. Of the

Piston compressor can be driven by a first drive device. The

Inlet assembly has a pre-compression device drivable by a second variable-power drive device for increasing the intake pressure and a cooling device for cooling the air to be compressed.

The proposed solution makes it possible, by the increased intake pressure and the reduced intake temperature of the intake air, the flow of a

Increase piston compressor, whereby its delivery performance increases.

The reciprocating compressor is a reciprocating compressor of a known type having a cylinder in which a piston arranged therein is axially movable and sucks air to be compressed in a reciprocating motion, in particular via an inlet valve arranged at the air inlet from an inlet arrangement, and in particular via an air outlet disposed exhaust valve against a pressure in an exhaust assembly ejects. The piston compressor is of a first Drive device drivable. Depending on the operational situation of the

Piston compressor is the first drive means an internal combustion engine, an electric drive device or other suitable drive means. A piston compressor according to the invention may be both a dry-running, that is to say oil-free piston compressor and a piston compressor which is not oil-free. Although in the invention advantages or embodiments are described which are not applicable to other than dry running reciprocating compressors, so again other advantages and embodiments are also applicable for reciprocating compressors, which are not running dry running.

In the proposed reciprocating compressor, the inlet arrangement has a variable power driven by a second drive means

Pre-compression device on. With this pre-compression device, the

Inlet pressure can be increased in particular at the air inlet by the variable power variably from an output pressure p ₀ up to a maximum pressure p _max . Due to the higher intake pressure of the first cylinder in multi-stage

Piston compressors or the single cylinder in single-stage reciprocating compressors, an increase in the volume flow is achieved by AV, since the compression chamber of the cylinder is filled with a higher pressure to be compressed air.

Also, the second drive means, which for driving the

Pre-compression device is used may be an electric drive device or other suitable drive device depending on the application situation. Likewise, the drive power of the second drive device can also be transmitted to it by the first drive device or another available drive device, for example by means of a variable-speed transmission

Translation. In particular, power transmitted by the second drive device can be variably adjusted.

In the proposed solution, the inlet arrangement comprises a cooling device, which through the air to be compressed, which flows through the inlet assembly through appropriate measures cools. In this case, the cooling device is arranged in particular in the flow direction of the intake air after the pre-compression device, since the air is heated by the pre-compression. But it is also possible, one

To arrange cooling device upstream of the pre-compression device in the flow direction, especially if this is advantageous due to structural conditions. In this arrangement, a larger lowering of the temperature is required because the

Air temperature increased again by the pre-compression. In one embodiment of the reciprocating compressor can also be provided to cool the intake air before and after the pre-compression.

In particular, the inlet arrangement also has at least one conduit device which directs the intake air to the at least one cooling device and to the at least one compression device and to connect these with one another and / or with the

Connect the air inlet of the compression chamber. In particular, a cooling device can also be arranged on the outside of a conduit device. As appropriate

Cooling means of the inlet arrangement can, for example

Coolant heat exchangers or means for enlarging the outer surface of the inlet assembly or a conduit means such as loops or cooling fins, which are used for example in conjunction with blowers, or any other suitable type of means by which the suction air flowing in the inlet assembly heat energy can be withdrawn.

The proposed solution makes it possible to increase the volume flow of a reciprocating compressor by the factor of Vorverdichtungseinrichtung.

po

Due to the increased intake pressure and the reduced intake temperature of the intake air, the delivery performance of the piston compressor increases. The variable power of the precompression device, in conjunction with the increase in power of the reciprocating compressor, allows for a wider control spectrum of the reciprocating compressor. Thus, the use of reciprocating compressors with a smaller overall size is possible, since higher volume flows are realized by the increased intake pressure. The proposed solution allows a regulated compressor operation with briefly very high performance during refilling operation (large volume flow of the reciprocating compressor) and a constant operation with low power (lower volume flow of the reciprocating compressor) in normal operation. Thus, there is no risk of vibration by free mass forces at low speeds and the maximum relative speeds of particular oil-free bearings can be maintained. In addition, by the proposed solution, the overall temperature level of a reciprocating compressor can be lowered.

The proposed solution thus increases the control range of the volume flow and thus the delivery performance of a compressor, leading to the reduction of relevant

Temperature levels and at the same time increases the energy efficiency and power density of the reciprocating compressor.

The reciprocating compressor is driven by a crankshaft, which in one

Crankcase is rotatably mounted. One or more connecting rods each connected to a piston are rotatably mounted on an eccentric position of the crankshaft such that its rotational movement is transmitted as a lifting movement to the piston which moves axially in a cylinder. The reciprocating compressor has at least one cylinder for compressing air, but may also have two or more cylinders arranged in succession or in parallel, which are provided for compressing air by means of a respective piston arranged movably therein, so that the reciprocating compressor is designed in one or more stages can.

In one embodiment of the reciprocating compressor, the latter has a crankcase, in which a crankshaft is arranged, on which at least one connecting rod connected to a piston is rotatably mounted, wherein the intake air of the at least one cylinder is guided through the crankcase.

In this embodiment, the intake air of the at least one cylinder is guided through the crankcase, wherein it over the elements of the crank mechanism, in

Essentially the crankshaft, the connecting rods, the underside of the piston or pistons and the interposed bearing elements flows and cools them. In the

Intake air is essentially the air that is later sucked into the at least one cylinder of the reciprocating compressor and compressed there. In one embodiment of the reciprocating compressor, the inlet arrangement has an air discharge device. This embodiment makes it possible to guide a larger volume flow through the crankcase than is later taken up as intake air in the at least one cylinder of the reciprocating compressor and compressed there. Thus, the cooling air volume flow in the crankcase can be increased and at the same time the heating of the intake air when flowing through the crankcase can be reduced.

The Luftableiteinrichtung may be formed, for example in the form of a check valve or pressure relief valve, which opens from a predetermined pressure of the intake air. However, the Luftableiteinrichtung can also be designed so that it can be opened and closed depending on predetermined parameter values, in particular by a control device. In one embodiment of a

Luftableiteinrichtung is in particular excess intake air from the

Intake arrangement discharged into the environment, in another embodiment of a Luftableiteinrichtung, for example, a predetermined proportion of the cooled volume flow of the intake air can be returned to the crankcase.

In a further embodiment of the reciprocating compressor is a

Aftercooling arranged for cooling the compressed air after passing through the at least one cylinder of the reciprocating compressor. In particular, the outlet arrangement has a post-cooling device for cooling the compressed air. By compressing the air in the cylinder heats up, so that through the

Air outlet from the compression space ejected compressed air has an elevated temperature. Cooling of the compressed air after passing through the at least one cylinder by means of at least one Nachkühlseinrichtung of

For example, outlet arrangement simplifies subsequent storage of the air or further processing such. B. a dehumidification of the air. At a

Embodiment of the reciprocating compressor is the Nachkühleinrichtung the

Outlet assembly formed by a partition of the cooling device for cooling the intake air of the inlet assembly. In a further embodiment, the reciprocating compressor has a

Control device, with which the power of the pre-compression device and thus the suction pressure at the air inlet is in particular continuously adjustable. The

Control device is operatively connected to the second drive means which drives the pre-compression device with variable power. The

Control device receives signals and / or measured values, which are in particular associated with the required delivery of the reciprocating compressor and by means of which the control device, the power of the second

Drive device and thus the pre-compression adjusts. In this way, the degree of precompression of the air flowing through the inlet arrangement into the cylinder is regulated by means of the precompression device.

To achieve the object, a method for controlling a

Piston compressor proposed above, the

Regulation means the performance of the pre-compression between a maximum value corresponding to a maximum suction pressure (p _ma x) at the air inlet and a minimum value which corresponds to the suction pressure generated by the piston stroke movement in the cylinder (p ₀ ) at the air inlet controls. This is the

Delivery performance of the reciprocating compressor by the inventive method in an extended control range between a maximum intake pressure and a minimum intake pressure at the air inlet in particular continuously adjustable. In this way, the control range of the compressor volumetric flow increases, increasing energy efficiency and power density. In one embodiment of the method for controlling the reciprocating compressor, the regulating device is signal-connected to at least one signal generator and / or at least one sensor, wherein the regulating device controls the power of the

Pre-compression device in response to at least one value and / or signal from this at least one signal generator and / or sensor controls. Of the

Control device are transmitted for each of the currently required delivery performance of the reciprocating compressor of at least one sensor and / or at least one signal generator relevant values or signals, from which the control device determines the currently required volume flow and the power of Pre-compression device governs according to this need. In this way, by means of the control device, the volume flow of the reciprocating compressor

For example, depending on a current requirement, the operating state or the current situation of the compressor having system, such as a rail vehicle, adapted.

In a further embodiment of the method, the control device receives values from at least one sensor. For this purpose, the at least one sensor is selected from a group which, in particular, pressure sensors,

Temperature sensors, flow sensors, speed sensors or other suitable sensors. These sensors detect relevant parameter values, in particular for the regulation of the pre-compression device. For example, a suitable pressure sensor senses the pressure in the pressure system supplied by the piston compressor. This can, for example, at the outlet before or after a

optionally arranged there after-cooling device or be positioned in the compressed air tank. Depending on the pressure value recorded in the compressed air system, rapid filling may be required, with a high delivery rate of the

Piston compressor is required, or replenishment of smaller amounts of extracted compressed air, which can be done more economically with a lower delivery performance.

By means of a volumetric flow sensor, the volumetric flow taken from the compressed air system can be detected directly. This value also influences, for example, the required amount of compressed air during refilling operation of the reciprocating compressor. By means of a speed sensor, the speed of the crankshaft to the

Control device transmitted, can in the process of controlling the

Reciprocating a value for the volume flow, which flows through the intake assembly. With a temperature sensor, for example, the air temperature in the crankcase, in the inlet assembly, in the outlet arrangement or in the compressed air system can be detected, from which also different requirements for the delivery of the reciprocating compressor can be derived, with the aid of

Control device can be adjusted. In one embodiment of the method for controlling a reciprocating compressor, the regulating device is signal-connected to at least one signal generator, which is selected from the group consisting of operating management systems,

Control means such as a controller of the first drive means or other suitable means which process information relevant to the control of the delivery performance of the reciprocating compressor. From a vehicle management system receives a control device for a

Piston compressor, for example, values relating to the current operating state of a vehicle, such as the driving speed, braking operation or track operation and the like, from which the current compressed air consumption and the currently required level of the compressed air system can be derived. Also due to signals from the controller of the first drive means, the

Control device to derive information regarding the current operating situation and the operating state of the system in which the piston compressor is currently used and from this can determine and apply control values for the required volume flow of the reciprocating compressor.

In one embodiment of the method for controlling a reciprocating compressor, the regulating device regulates the power of the cooling device independently of the power of the precompression device. The setpoints for the performance of the

Cooling device can be transferred directly to the control device. Likewise, the control device can determine the setpoint to be adjusted in particular depending on sensor or signal transmitter values, which, for example, the temperature of the environment, in the crankcase or in the

Compressed air tank included. In this case, a greater or lesser cooling capacity of the cooling device can be independent of the power of the pre-compression device

be required to cause, for example, a greater or lesser compression of the air in the reciprocating compressor, or to indirectly influence the temperature level of the pressure system by a lower or higher temperature of the intake air of the reciprocating compressor.

Further advantages, features and applications of the present invention will become apparent from the following description taken in conjunction with the figures. Fig. 1 shows a schematic representation of a first embodiment of an exemplary piston compressor according to the invention; Fig. 2 shows a schematic representation of a second embodiment of an exemplary piston compressor according to the invention; and

Fig. 3 shows a diagram in which the volume flow change is represented by the increase of the inlet pressure.

Fig. 1 shows a schematic representation of a first embodiment of an exemplary piston compressor according to the invention 10. The oil-free in the exemplary embodiment, ie dry-running piston compressor 10 has a crankcase 20 and a crankshaft 21 disposed therein, which with a first

Drive device 22 is connected and driven by this. The im

Embodiment single-stage piston compressor 10 has a cylinder 1 1 with a compression chamber 14 for compressing air by means of a cylinder 1 1 arranged in the piston 12, which is driven via an eccentrically rotatably mounted on the crankshaft 21 connecting rod 13.

The cylinder 1 1 has an air inlet 30, which is connected to an inlet arrangement 31, which leads to compressed air to the air inlet 30 of the compression space 14. Furthermore, the cylinder 1 1 an air outlet 33, which with a

Outlet assembly 34 is connected, which compressed air from the

Compression chamber 14 receives. The crankshaft 21 forms, with the connecting rod 13 and the bearings arranged thereon and between these, the crank mechanism 15, which heats up within the crankcase 20 during operation of the piston compressor 10.

The crankcase 20 of the exemplary embodiment is above a

Air supply line 25 is connected to an air filter 26, via which

Sucked in ambient air and is guided via the air supply line 25 into the crankcase 20. At a remote from the connection of the air supply line 25 portion of the crankcase 20, the inlet assembly 31 is arranged so that the from the air supply line 25 into the crankcase 20 guided air after flowing through the crankcase 20 this can leave through the inlet assembly 31 again. The thereby formed air stream flows over in particular the

Elements of the crank mechanism 15 and takes while cooling the

Crankshaft 15 heat energy up.

The inlet arrangement 31 has a pre-compression device 28 in the form of an external high-performance blower, which is driven by a supercharger drive (second drive device) 29. By the effect of

Pre-compression device 28 is ambient air through the air filter 26 in the

Suction crankcase 20, where it flows over the elements of the crank mechanism 15 and thereby removes heat energy. The pre-compression device 28 sucks the heated air after flowing through the crankcase 20 in the

Inlet assembly 31, this compresses and builds depending on the current performance of the supercharger drive 29 at the air inlet 30 in front of the cylinder 1 1 a relative to the ambient pressure increased pressure. This increased pressure at the air inlet 30 allows more air to flow into the compression space 14 during a suction stroke of the piston 12, thereby increasing the delivery performance and efficiency of the reciprocating compressor 10.

In the exemplary embodiment of FIG. 1, the inlet assembly 31 between the pre-compression device 28 and the cylinder 11 has a cooling device 32 which cools the air flowing through the inlet assembly 31. Both when flowing through the crankcase 20 as well as by the pre-compression in the pre-compression device 28, the intake air heats up, resulting in a

Volume enlargement leads, which causes a reduction in the intake chamber during an intake stroke in the compression chamber 14 amount of air. To counteract this effect, the inlet assembly 31 in the flow direction of

Intake air after the pre-compression device 28 on a cooling device 32, which cools the pre-compressed intake air. As a result, a larger amount of air can be absorbed in the compression chamber 14. By this measure, the

Delivery performance and efficiency of the reciprocating compressor 10 further increased. The supercharger drive 29 is connected in the exemplary embodiment of the reciprocating compressor 10 with a control device 40, which regulates the power of the pre-compression device 28 and thus the suction pressure at the air inlet 31. At the inlet assembly 31 and at the outlet assembly 34 of the

Piston compressor 10 are arranged at suitable locations a plurality of pressure sensors 41 a, 41 b, 41 c and a plurality of temperature sensors 42 a, 42 b, 42 c, which are each signal-connected to the control device 40 (not shown). The

Pressure sensors 41 a, 41 b, 41 c and the temperature sensors 42 a, 42 b, 42 c transmit the respectively prevailing air temperature or the pressure at their respective position on the inlet arrangement 31 and on the outlet arrangement 34 to the

Control device 40.

Furthermore, the control device 40 is signal-connected to a device management system 45, which transmits further data relevant to the compressed-air supply of the reciprocating compressor 10 to the control device 40. From the data, which receives the control device 40 in particular from the pressure sensors 41 a, 41 b, 41 c, the temperature sensors 42 a, 42 b, 42 c and the device management system 45, the control device 40 determines the current needs of

Compressed air supply system and thus the required delivery of the

Piston Compressor 10. With the following requirement demand fits the

Control device 40 by a suitable control of the supercharger drive 29, the degree of pre-compression of the intake air at the air inlet 31 by means of

Pre-compression device 28 accordingly. In a further, not shown exemplary embodiment of the

The piston compressor according to the invention 10 is also a power control of the cooling device 32 and the Nachkühleinrichtung 35 connected to the control device 40. In this case, then, the cooling capacity of the two cooling devices 32, 35 by means of the control device 40 to a particular determined in each case

required cooling capacity to be regulated.

FIG. 2 shows a schematic representation of a second embodiment of an exemplary piston compressor 10 according to the invention. The piston compressor 10 from Fig. 2 corresponds largely to the piston compressor 10 shown in FIG. 1 and described for this purpose, so that the same elements of the reciprocating compressors 10 are denoted by the same reference numerals. In the following, only the

Differences between the two piston compressors 10 shown schematically explained.

The piston compressor 10 shown in FIG. 2 has, relative to the piston compressor 10 from FIG. 1, an air discharge device 36 in the form of a pressure relief valve arranged on the inlet arrangement 31. In the embodiment shown, the pressure relief valve of the Luftableiteinrichtung 36 opens as soon as the pressure in the inlet assembly

31 in the flow direction of the intake air to the cooling device 32 a

exceeds predetermined value and guides the excess intake air in the

Inlet assembly 31 to the environment of the reciprocating compressor 10 from. In this way, the volume flow of air for cooling the crankcase 20 may be greater than the delivery capacity of the reciprocating compressor 10, since the excess air after flowing through the crankcase 20 and after the precompression of the inlet assembly 31 can be removed.

In this exemplary embodiment, a largely arbitrarily large

Air flow through the crankcase 20 realized, wherein the cooling device

32 possibly opposite to the reciprocating compressor 10 of Fig. 1 for the

Increased volume flow is designed to be larger. When compared with the

Piston compressor 10 of FIG. 1 same delivery performance also increases the amount of air sucked through the air filter 26.

Fig. 3 shows a diagram showing the change of the piston compressor 10th

promoted volume flow due to a pre-compression and cooling of the intake air as it flows through the inlet assembly 31 illustrates. In the diagram, the pressure of the intake air at the air inlet 30 is higher than that of the piston compressor 10

conveyed volume flow shown.

The funded by a piston compressor 10 according to the prior art

Volume flow 51 is shown by a dashed curve. The one by one piston compressor according to the invention 10 funded flow 52 is illustrated by a continuous curve.

As can be seen from the diagram, increasing the intake pressure p _e o by Ap _e to p _e i through the pre-compression and cooling of the intake air increases the volumetric flow by AV to Vi, since the displacement volume of the compression space V _{0 is} greater Air quantity is filled as in a piston compressor 10 according to the prior art.

The features of the invention disclosed in the foregoing description, in the drawings and in the claims may be essential to the realization of the invention both individually and in any combination.

LIST OF REFERENCE NUMBERS

10 piston compressor

1 1 cylinder

12 pistons

13 connecting rods

14 compression space

15 crank drive

20 crankcase

21 crankshaft

22 first drive device

25 air supply line

26 air filters

28 pre-compression device

29 supercharger drive

30 air intake

31 inlet arrangement

32 cooling device

33 air outlet

34 outlet arrangement

35 post-cooling device

36 air discharge device

40 control device

41 a, b, c pressure sensor

42a, b, c temperature sensor

45 device management system

51 Volume flow of a piston compressor of the prior art

52 flow rate of a piston compressor according to the invention

Claims

1 . Piston compressor having at least one cylinder (1 1) for compressing air with a piston arranged therein (12) in a above the piston (12) in the cylinder (1 1) arranged compression chamber (14), wherein the compression chamber (14) an air inlet (30) and an air outlet (33) and is connected to the air inlet (30) with an inlet assembly (31) for air to be compressed and on

Air outlet (33) is connected to a compressed air outlet arrangement (34), wherein the piston compressor (10) by a first drive means (22) is driven, characterized in that the inlet arrangement (31) by a second drive means (29) with changeable power drivable

Pre-compression device (28) for increasing the suction pressure and a

Cooling device (32) for cooling the air to be compressed.

2. Piston compressor according to claim 1, characterized by a crankcase (22) in which a crankshaft (21) is arranged, on which at least one with a piston (12) connected connecting rod (13) is rotatably mounted, wherein the intake air of the at least one Cylinder (1 1) through the crankcase (20) is guided.

3. Piston compressor according to one of the preceding claims, characterized in that the inlet arrangement (31) has a Luftableiteinrichtung (36).

4. Piston compressor according to one of the preceding claims, characterized by a Nachkühleinrichtung (35) for cooling the compressed air after passing through the at least one cylinder (1 1) of the reciprocating compressor (10).

5. Piston compressor according to one of the preceding claims, characterized by a control device (40), with which the performance of

Pre-compression device (28) and thus the suction pressure at the air inlet (30) is adjustable.

6. A method for controlling a reciprocating compressor according to claim 5, characterized in that the control device (40), the power of

Pre-compression device (28) between a maximum value, the one

maximum intake pressure (p _ma x) at the air inlet (30) and a minimum value which corresponds to the suction pressure (Po) generated by the piston stroke in the cylinder (1 1) at the air inlet (30) controls.

7. A method for controlling a reciprocating compressor according to claim 6, characterized in that the control device (40) with at least one

Signal transmitter (45) and / or at least one sensor (41 a, 41 b, 41 c, 42 a, 42 b, 42 c) is signal-connected, wherein the control device (40), the power of

Pre-compression device (28) in response to at least one value and / or signal from this at least one signal generator (45) and / or sensor (41 a, 41 b, 41 c, 42 a, 42 b, 42 c) controls.

8. A method for controlling a reciprocating compressor according to claim 7, characterized in that the at least one sensor (41 a, 41 b, 41 c, 42 a, 42 b, 42 c) is selected from a group which in particular pressure sensors (41 a, 41 b , 41 c), temperature sensors (42 a, 42 b, 42 c), volumetric flow sensors and speed sensors.

9. A method for controlling a reciprocating compressor according to claim 7 or 8,

characterized in that the at least one signal generator (45) is selected from a group which in particular has operating management systems (45) or control devices.

10. A method for controlling a reciprocating compressor according to one of claims 6 to 9, characterized in that the control device (40) regulates the power of the cooling device (32) independently of the power of the pre-compression device (28).