EP3821130A2

EP3821130A2 - Scroll compressor

Info

Publication number: EP3821130A2
Application number: EP19742309.8A
Authority: EP
Inventors: Andreas Inhoff; Simon SCHMIDER; Thomas Hartmann; Walter Zipp
Original assignee: Ipetronik GmbH and Co KG
Current assignee: Ipetronik GmbH and Co KG
Priority date: 2018-07-10
Filing date: 2019-07-09
Publication date: 2021-05-19
Also published as: DE102018116630A1; WO2020011769A2; WO2020011769A3

Abstract

The invention relates to a scroll compressor which comprises the following: a compressor unit (20) having a stationary stator spiral element (21) and a rotatable rotor spiral element (22) which is mounted so as to be axially movable relative to the stator spiral element (21), wherein the compressor unit (20) is designed to suction and compress a fluid to be compressed from a suction region (30) and to convey it into a high-pressure region (40); a counter-pressure chamber (10) which is arranged on a side of the rotor spiral element (22) facing away from the stator spiral element (21) and which can be subjected to a counter-pressure in order to exert a pressing force on the rotor spiral element (22) in the axial direction and to press the rotor spiral element (22) against the stator spiral element (21); wherein a fluid connection exists between the counter-pressure chamber (10) and the suction region (30), and wherein a fluid connection exists between the counter-pressure chamber (10) and the high-pressure region (40); a suction pressure channel (103) which is arranged in the fluid connection between the counter-pressure chamber (10) and the suction region (30); a high-pressure channel (104) which is arranged in the fluid connection between the counter-pressure chamber (10) and the high-pressure region (40); wherein at least one actuator element (101, 102, 101a) is arranged in the high-pressure channel (104) and the suction-pressure channel (103), by means of which the cross-section of the high-pressure channel (102) and of the suction pressure channel (103) can be changed.

Description

Scroll compressor

description

The present invention relates to a scroll compressor according to claim 1 and

Claim 8.

In passenger cars (cars), in addition to belt-driven ones

Refrigerant compressors are increasingly using electrically driven refrigerant compressors. The electrically driven refrigerant compressor has become the standard, particularly in hybrid vehicles and purely electrically powered vehicles. By using your own electric motor, it will

Auxiliary unit independent of the speed of the vehicle drive train and thus allows a wide range of control options.

The electrically driven refrigerant compressors that are used in passenger cars are often designed as scroll compressors. On

Scroll compressor has two spiral elements that run into each other

Spiral contours. One of these spiral elements, the stator spiral element, remains stationary while the other spiral element, the

Rotor spiral element, by a rotating electric motor and a special intermediate drive relative to the stator spiral element in an orbiting

Movement. The crescent-shaped volumes enclosed between the spiral contours decrease in size due to the movement sequence towards the center of the compressor ever further. This allows a gaseous refrigerant, which is introduced from the edge between the spiral contours, to be compressed. The refrigerant compressed in this way is then used as a so-called hot gas

Check valve pushed out.

The radial sealing between the spiral contours takes place via liquid oil, which is entrained by the mass flow of the gaseous refrigerant during operation. On the other hand, the axial sealing takes place via sealing elements on the edges of the spiral contour of the rotor spiral element and its axial contact pressure.

The ideal value of the axial contact force depends on the operating range of the

Scroll compressor. If the seal is insufficient, internal leakage can occur, which reduces efficiency and can lead to loss of contact on the axial sealing lines. On the other hand, an unnecessarily high contact pressure leads to increased friction and wear. An uncontrolled change in contact pressure, which leads to a lifting and putting on the rotor spiral element from

Stator spiral element can also lead to the risk of wear and direct damage.

The aim of the invention is therefore to optimize the axial setting

Depending on the pressing force of the rotor spiral element with high flexibility

To enable requirements of the operating state of the scroll compressor. This means that parameters such as operational safety, wear,

Efficiency and noise generation can be improved.

This object is achieved by a scroll compressor according to claim 1 and a scroll compressor according to claim 8.

In particular, the object is achieved by a scroll compressor which has the following: a compressor unit with a fixed stator spiral element and a rotatable rotor spiral element which is mounted so as to be axially movable relative to the stator spiral element, the compressor unit being designed to suck in, compress and compress a fluid to be compressed from a suction area to promote in a high pressure area; a back pressure chamber, which on a side facing away from the stator spiral element

Rotor spiral element is arranged and can be acted upon with a back pressure to apply a pressing force in the axial direction on the rotor spiral element to exert and to press the rotor spiral element against the stator spiral element, wherein there is a fluid connection between the back pressure chamber and the suction area, and wherein there is a fluid connection between the back pressure chamber and the high pressure area; a suction pressure channel arranged in the fluid connection between the back pressure chamber and the suction area; a high pressure channel disposed in the fluid communication between the back pressure chamber and the high pressure area; wherein at least one actuator element in the high pressure channel and the suction pressure channel

is arranged, by means of which the cross section of the high pressure channel and the suction pressure channel can be changed.

An essential point of the invention is that the provision of the actuator elements and the thus variable cross-section of the pressure channels overcome the limitations of fixed cross-sectional relationships or mechanically acting control elements for determining the contact pressure. The back pressure in the back pressure chamber can be controlled reliably, precisely and quickly by providing the actuator elements. This allows the

provided in particular for pressure channels with fixed cross sections

Safety surcharge of the contact pressure can be significantly reduced.

The friction that occurs in the compressor unit between the stator spiral element and the orbiting rotor spiral element can thus be reduced. As a result, the hot gas temperature is reduced. In this way, the cooling capacity and efficiency can be increased, the energy consumption of the scroll compressor reduced and, due to the reduced friction, the service life of the

Compressor unit can be increased. In addition, dynamic

Adjustment of the contact pressure the generation of vibrations of the

Rotor spiral element are suppressed along the axial direction, which would contribute to increased noise in addition to additional wear.

In addition, the back pressure can be quickly and reliably adapted to changing operating conditions of the scroll compressor with the present invention. This makes, for example, an adaptation to different

Refrigerant enables. The actuator elements according to the invention are components which contain electrical signals, for example commands originating from a control computer

implement mechanical movement or other physical quantities.

Actuator elements thus actively intervene in the process of controlling the contact pressure. For this purpose, the actuator elements have, for example, an electrical and / or a mechanical and / or a pneumatic and / or a hydraulic

Interface on. They thus provide the opportunity to change the cross-section of the high-pressure duct and the suction pressure duct quickly and easily.

In a preferred embodiment, the actuator element of the high-pressure duct and / or the actuator element of the suction pressure duct is formed by an actuator element with an orifice geometry, a needle valve, a ball valve, a throttle valve or a shape memory wire.

All of these constructive designs of the actuator elements can be controlled by means of the interfaces described above and represent a reliable possibility of setting the cross section of the high pressure duct and the suction pressure duct.

An actuator element with an aperture geometry is mechanically robust and takes up little installation space in the axial direction. A needle valve has a cylindrical shaft with a tapered tip. In the closed position, this conical tip sinks into a conical bore. The needle tip is axially adjusted, for example, by means of a stepper motor or a current-carrying coil and gives one

circular cross section free, the further the needle tip lifts out of the conical bore.

In the design as a ball valve, the actuator element is designed on the principle of a ball valve. Here a pierced ball is used as a shut-off body, which sits in a congruently shaped cavity in the pipe.

By rotating the pierced ball through 90 ° about an axis perpendicular to the piercing, the ball valve can be transferred from a fully open state to a fully closed state. The rotation can in turn be brought about, for example, by a stepper motor which is coupled to the ball valve directly or via a gear. Furthermore, the change in the channel cross section can be achieved in that the actuator element is designed as a throttle valve. here too, the closure element can be driven by a stepper motor or by means of a current-carrying coil. Other common drive concepts such as gear or worm gear are also an option

To generate movement.

The actuator element can also be formed by a shape memory wire. Here, a metal wire made of a special alloy is provided in the cross section of the pressure channel, the wire changing its shape or its diameter depending on the current intensity when current is applied, in order to change the cross section of the pressure channel.

In a (further) preferred embodiment, the actuator element of the high-pressure channel and the actuator element of the suction pressure channel is a

Mixing valve formed, which is connected to the high pressure channel, the suction pressure channel and the back pressure chamber. The mixing valve has at least two inputs, each of which is connected to the high-pressure duct and the suction pressure duct, and at least one output, which is connected to the

Back pressure chamber is connected. This represents a structurally simple and robust solution for setting the back pressure in the back pressure chamber. To set the back pressure, the mixing valve can be connected to at least one electrical control unit.

It is further preferred that the scroll compressor has a sensor element that is designed to measure a measurement variable from which the contact pressure that can be generated by the counterpressure in the counterpressure chamber can be determined.

With knowledge of the contact pressure, the control of the back pressure can be carried out much more precisely and reliably using the actuator elements.

In a preferred embodiment, the sensor element is a

Pressure sensor is formed, which is designed to measure the back pressure prevailing in the back pressure chamber. This enables a conceptually simple and reliable determination of the contact pressure. Is the effective area of the

Known rotor spiral element, on which the back pressure is present in the back pressure chamber, the pressure force can be easily calculated from the product of the measured pressure and the effective area. Alternatively, the sensor element can be formed by a force sensor, which on a drive shaft connected to the rotor spiral element, the

Rotor spiral element or the stator spiral element is arranged. The force sensor is designed so that it measures a force in the axial direction, so that the contact pressure can be determined directly. Can as a force sensor

force-correlating sensors are used, such as strain gauges or piezoelectric elements. Strain gauges change their resistance when deformed. An electrical voltage occurs in piezoelectric elements when deformed. With both sensor types, electronic detection of a force acting on the rotor spiral element or the stator spiral element is possible.

It is further preferred that the scroll compressor has a control unit that is designed to control the at least one actuator element, such that the one that can be generated by the back pressure in the back pressure chamber

Contact pressure can be controlled, in particular as a function of the contact pressure determined by means of the sensor element. By combining the actuator system provided by the actuator elements and a control circuit with the

Actual contact pressure as a control variable makes it possible to apply an optimal contact pressure in every operating state of the scroll compressor

Adjust the cross-sections of the high-pressure duct and the suction pressure duct.

Within the scope of the invention, a scroll compressor is also specified, which has the following: a compressor unit with a stationary one

Stator spiral element and a rotatable, in relation to the stator spiral element axially movably mounted rotor spiral element, wherein the compressor unit is designed to suck in a fluid to be compressed from a suction area, to compress it and to convey it to a high pressure area; a drive shaft that with the rotor spiral element on a

Stator spiral element facing away is coupled to a

To transmit rotational movement to the rotor spiral element, and which is movably mounted in the axial direction; and an actuator which is designed to exert a pressing force on the drive shaft in the axial direction in order to press the rotor spiral element against the stator spiral element. By integrating an actuator along the axial direction in which the rotor spiral element and the stator spiral element lie opposite one another, it is possible, via the mechanical movement of the actuator, to generate the contact pressure with which the rotor spiral element must be pressed against the stator spiral element. Since the press force can be variably adjusted, the advantages described above also result in this embodiment of the invention. A particular advantage of this variant of the contact pressure generation is that there is no supply of refrigerant that has already been compressed from the high pressure side back into the compression process. This means that there is almost no leakage current at the compressor unit

volumetric efficiency increases. In general, both applications are possible that directly transfer an actuator movement to the shaft, e.g. by means of a stepper motor with tappet arranged on the drive shaft, as well as indirect power transmission by means of levers or a gear.

An actuator is generally to be understood as a drive element which converts electrical signals, for example from control electronics, into mechanical movement.

In a preferred embodiment, the actuator is formed by a piezoelectric element. This enables a particularly precise setting of the

Contact force.

It is further preferred that the scroll compressor has a sensor element that is designed to measure a measurement variable from which the contact pressure that can be generated by the actuator can be determined. This allows more precise control of the contact pressure, with which changes in the operating state of the scroll compressor can be taken into account.

It is further preferred that the sensor element is formed by a force sensor which is attached to the drive shaft, the stator spiral element or the

Rotor spiral element is attached. This enables direct and

reliable determination of the contact pressure. The force-correlating sensors described above can in turn be used as force sensors.

In a (further) preferred embodiment, the scroll compressor has a control unit which is designed to control the actuator in such a way that the Contact force that can be generated by the actuator can be controlled, in particular in

Dependence on the contact pressure determined by means of the sensor element. The provision of an adjustable contact pressure for the rotor spiral element in combination with a control of the contact pressure based on the determined

Contact pressure in turn enables precise adjustment of the contact pressure in every load and operating state of the scroll compressor.

It is further preferred that the scroll compressor has an oil return, which forms a fluid connection between the high pressure area and the suction area, in order to return oil located in the high pressure area to the suction area, wherein an oil return actuator element is arranged in the oil return, by means of which the cross section of the Oil return is changeable. In the scroll compressor, the radial sealing between the orbiting scroll elements takes place by the provision of liquid oil, which is carried away by the suction area into the compressor unit and after

Compression process in the high pressure area from the compressed fluid

is deposited. Analogously to the use of actuator elements for setting the back pressure described in the embodiment according to claim 1, the cross section of the oil return and thus the oil return can also be varied for the oil return by using the oil return actuator element

Control oil return depending on the operating state of the scroll compressor. The types of actuator elements described above can in turn be used for the oil return actuator element. Alternatively, a solenoid valve can be used as the oil return actuator element, which can only assume an open or closed position. The amount of oil returned can then be controlled by controlling a clock frequency with which the solenoid valve is opened and closed.

It is further preferred that the scroll compressor has a fill level sensor which is designed to measure an oil fill level in the high pressure region.

In this way, the oil return can be further optimized.

In a preferred embodiment, the scroll compressor has one

Speed sensor, which is designed to a speed of the

To measure the rotor spiral element. This allows more precise control of the scroll compressor, in particular the contact pressure, since the speed sensor can also be used to detect rotational irregularities in addition to the speed can be caused by the compression process due to the load. By taking this parameter into account when setting the contact pressure, irregular rotary movements can be actively compensated.

It is further preferred that the scroll compressor has a rotary drive control which is designed to rotate the

To control the rotor spiral element as a function of the speed determined by means of the speed sensor. In combination with the speed sensor, for example, the rotational force with which the rotary drive can

Drives the rotor spiral element, be reduced as soon as, for example, compression has taken place in the compressor unit and the torque load on the drive shaft decreases briefly until the next pressure maximum in the compressor unit.

In a further preferred embodiment, the scroll compressor has a high-pressure sensor which is designed to measure a pressure in the

To measure the compressor unit. The high pressure sensor is preferably a

Highly dynamic pressure sensor with low hysteresis, which is designed to measure the maximum pressure of the fluid to be compressed in the high pressure chamber in the direction of flow of the fluid in front of an outlet in the high pressure chamber.

It is further preferred that the rotary drive control is designed to control the control of the rotary drive as a function of the pressure in the compressor unit. This can cause a pressure surge in the

Compressor unit a sudden increase in the speed of the

Rotor spiral element are compensated, which is caused by the fact that the speed increases sharply with a constant torque of the rotary drive in the event of a pressure drop in the compressor unit. This can actively reduce rotary shocks during operation of the scroll compressor.

It is further preferred that the scroll compressor has a temperature sensor which is designed to measure a temperature of the fluid to be compressed in the high pressure region, preferably directly at an outlet of the

To measure the compressor unit. On the one hand, this can be provided as a safety measure to prevent the scroll compressor from exceeding one

Switch off limit temperature. On the other hand, with the help

Corresponding material data that can be stored on a control unit, the State of matter of the fluid to be compressed in the high pressure area can be determined. In this way it can be determined whether liquid refrigerant can be present in the compressor unit. Accordingly, it is then possible that

To control the startup behavior of the scroll compressor in a suitable manner.

It is further preferred that the control unit is designed to:

Contact force depending on the speed and / or the current angle of rotation and / or the pressure in the compressor unit and / or the

Control the temperature of the fluid to be compressed in the high pressure range. Depending on the operating state during a work cycle, this can be done in the course of a

Rotation of the rotor spiral element, the axial force can be controlled. When a prematurely falling high pressure is detected in the compressor unit, for example, the axial force can be directly applied to the changed one

Adjust operating conditions and dynamically while running a

Optimize the rotation of the rotor spiral element.

Thus, the wear of the compressor unit can be reduced and the service life of the compressor unit can be increased, the efficiency of the scroll compressor can be further improved and the excitation of oscillations and vibrations by a periodic axial movement of the rotor spiral element during the

Compression process can be suppressed. Especially when using the

Invention for a scroll compressor for cars can then be dispensed with conventional measures for reducing vibrations such as corresponding mechanical decouplings, bearings, damping elements, the integration of additional masses or the like.

Further advantageous embodiments of the invention result from the

Dependent claims.

In the following, the invention is also described with regard to further features and advantages on the basis of various exemplary embodiments, which are explained in more detail with reference to the figures. Features of the exemplary embodiments can be combined with one another. Show here;

Fig. 1 shows a section of a scroll compressor according to a first

Embodiment of the present invention;

FIG. 2 shows a modification of the scroll compressor according to FIG. 1 with a modified one

Pressure channel management;

3 shows a modification of the scroll compressor according to FIG. 2 with a

modified version of the actuator element;

FIG. 4 shows a modification of the scroll compressor according to FIG. 3 with a

Sensor element;

5 shows a modification of the scroll compressor according to FIG. 1 with a

Sensor element;

6 shows a further modification of the scroll compressor according to FIG. 1 with a further alternative for a sensor element;

FIG. 7 shows a further modification of the scroll compressor according to FIG. 1 with a further alternative for a sensor element;

Fig. 8 shows a section of a scroll compressor according to a second

Embodiment of the present invention;

FIG. 9 shows a modification of the scroll compressor according to FIG. 8;

Fig. 10 shows a section of a scroll compressor according to another

Embodiment of the invention with an alternative actuator;

11 shows a modification of the scroll compressor according to FIG. 8 with a

Sensor element;

FIG. 12 shows a modification of the scroll compressor according to FIG. 11 with a

Oil recirculation actuator element; 13 shows a modification of the scroll compressor according to FIG. 12 with a level sensor;

FIG. 14 shows a modification of the scroll compressor according to FIG. 13 with a

Speed sensor;

15 shows a modification of the scroll compressor according to FIG. 14 with a

High pressure sensor;

16 shows a modification of the scroll compressor according to FIG. 15 with a

Temperature sensor.

1 shows a section of a scroll compressor according to a first

Embodiment of the present invention. The scroll compressor has a housing 50 with a substantially cylindrical shape. The cylinder axis Z of the housing 50 is shown with a dash-dotted line. The direction parallel to the cylinder axis Z of the housing 50 is referred to below as the axial direction.

Near the one axial end, the housing 50 has a fluid inlet 51 on the lateral surface, through which fluid to be compressed can be introduced into the scroll compressor. The fluid is introduced into a suction region 30 via the fluid inlet 51. A compressor unit 20 adjoins the suction area 30 in the axial direction, into which fluid is sucked in from the suction area 30 when the scroll compressor is in operation and compressed there. A high-pressure region 40 connects to the compressor unit 20 in the axial direction, into which the fluid compressed in the compressor unit 20 is conveyed and from which it flows out through a fluid outlet 52 in the housing 50 of the scroll compressor. The functional units of the scroll compressor are described in detail below.

A drive shaft 23 is arranged in the suction area 30 and is rotatably supported by means of two bearings 24a, 24b. The drive shaft 23 is rotatably connected to a rotor 24 of an electric motor, which is surrounded by a stator 25 of the electric motor. The drive shaft 23 can by means of electric motor are driven in rotation. The electronics required for controlling the electric motor are accommodated in an electronics housing 70 which is arranged adjacent to the housing 50 of the scroll compressor.

The suction area 30 is connected via a compressor feed line 27 to the

Compressor unit 20 connected. The compressor unit is essentially formed by two spiral elements, namely a stator spiral element 21 mounted immovably in the housing and a rotor spiral element 22 movably mounted relative to the stator spiral element 21. Both spiral elements have a base plate 21a, 22a, each of which extends perpendicular to the cylinder axis Z of the scroll compressor ,

A spiral wall 21b, 22b extends from the base plates 21a, 22a of the spiral elements in each case parallel to the cylinder axis Z. The spiral elements are arranged in the compressor unit 20 such that the spiral walls 21b, 22b interlock. The spiral walls of each spiral element extend to the bottom plate of the opposite spiral element. At the ends of the spiral walls 21b, 22b, which are in contact with the opposite base plates 22a, 21a, sealing elements are arranged, which are shown in FIG. 1 as black squares. The sealing elements serve to mutually seal the spiral elements in the axial direction.

The rotor spiral element 22 is offset from the stator spiral element 21 perpendicular to the cylinder axis Z. The rotor spiral element 22 is rotatably mounted on the drive shaft 23 by means of a bearing 24c, the rotor spiral element 22 being arranged eccentrically with respect to the drive shaft 23, as shown in FIG. 1.

By the eccentric with respect to the drive shaft 23 and rotatable on the bearing 24c bearing of the rotor spiral element 22, a rotation of the

Drive shaft 23 translated into an orbiting movement of the rotor spiral element 22 with respect to the fixed stator spiral element 21. During this orbiting movement, the spiral wall 22b rolls on the spiral wall 21b.

Sickle-shaped pockets are formed between the spiral walls 21b, 22b, which migrate in the direction of the center of the spirals during the orbiting movement of the rotor spiral element 22, the volume of which decreases. Thereby the fluid introduced into the compressor unit 20 radially from the outside via the compressor feed line 27 is compressed during the orbiting movement of the rotor spiral element 22.

The compressor unit 20 has a hot gas valve 26 on the side facing the high pressure region 40 near the cylinder axis Z, through which compressed fluid flows from the compressor unit 20 into a high pressure chamber 41 in the

High pressure area 40 is pushed out. The hot gas valve 26 is a

Check valve that blocks the flow of compressed fluid from the

Compressor unit 20 in the high pressure chamber 41 allows and a

Backflow of compressed fluid from the high pressure chamber 41 back into the compressor unit 20 is prevented.

The compressed fluid flows out of the high pressure chamber 41 via a

Overflow channel 43 in an oil separation chamber 42. For lubricating the electric motor in the suction area 30 and for radially sealing the

Spiral elements in the compressor unit 20 contain liquid oil in the suction area 30, which is in contact with the components of the electric motor and is entrained during the operation of the scroll compressor via the mass flow of the gaseous fluid in the suction area 30 when sucking into the compressor unit 20. The oil discharged into the high-pressure region 40 is separated in the oil separation chamber 42 in that the overflow channel 43 is formed in such a way that the passing mixture of oil and fluid substantially tangentially enters the oil separation chamber 42, which is cylindrical. The combination of tangential overflow channel 43 and cylindrical oil separation chamber 42 acts as a centrifugal separator.

Due to the tangential inflow into the cylindrical space, a vortex is formed in the area on the wall of the oil separation chamber 42. Under the influence of the centrifugal force, the oil is deposited on the wall, from where it flows to the bottom of the oil separation chamber 42. The fluid first flows around an immersion tube 44, which projects into the oil separation chamber 42 from above to below the height of the overflow channel 43, and rises to the fluid outlet 52 of the housing 50 after the oil has been separated off in the immersion tube 44. The flow of the fluid in the oil separation chamber 42 is indicated by an arrow in FIG. 1. The separated oil can via an oil return 60 at the bottom of the

Oil separation chamber 42 are directed back into the suction area 30.

In order to achieve the sealing required for the compression process in the axial direction, the movably mounted rotor spiral element 22 must be subjected to a pressing force in the axial direction in order to

To press the rotor spiral element 22 against the stator spiral element 21. For this purpose, a counter pressure chamber 10 is arranged on the side of the rotor spiral element 22 facing away from the stator spiral element 21. The

Back pressure chamber 10 is on one side of the bottom plate 22a of the

Rotor spiral element 22 limited. If the back pressure chamber 10 is pressurized, this causes a pressing force on the

Rotor spiral element 22, with which the rotor spiral element 22 against the

Stator spiral element 21 is pressed.

The back pressure chamber 10 is in fluid communication with a mixing chamber 105. The mixing chamber 105 is in fluid communication with the suction area 30 and the high pressure area 40. The fluid connection with the suction area 30 is established through a suction pressure channel 103. The fluid connection to the

High-pressure area 40 is produced by a high-pressure channel 104. The

The suction pressure channel 103 and the high pressure channel 104 are designed as bores in the housing 50.

Fluid flows into the mixing chamber 105 through the suction pressure channel 103 with a suction pressure prevailing in the suction region 30. Compressed fluid flows into the mixing chamber 105 at high pressure level via the high pressure channel 104. A counterpressure thus arises in the mixing chamber 105, which is derived from the proportions of suction and high pressure results. This pressure level also arises in the

Back pressure chamber 10 a.

In order to be able to set the back pressure in the mixing chamber 105, and thus the back pressure in the back pressure chamber 10, the cross sections of the

Suction pressure channel 103 and the high pressure channel 104 variable. This is achieved in that a first actuator element 101 is arranged in the suction pressure channel 103 and a second actuator element 102 is arranged in the high pressure channel 104. Depending on the cross sections of the two pressure channels 103 and 104, which are set by means of the actuator elements 101 and 102, the back pressure in the Back pressure chamber 10, and thus the contact pressure for the rotor spiral element 22 can be adjusted.

The actuator elements 101 and 102 are each shown in FIG. 1 connected to a stepper motor. The stepper motor of the actuator elements 101 and 102 generates a rotary movement which is transmitted to an actuator element which is arranged in the pressure channels and which changes the cross section of the respective pressure channel due to its movement. Specific possible embodiments for actuator elements are, for example, orifices, needle valves, ball valves or throttle valves. Instead of a motor-operated actuator element, other devices can be used that allow a controlled change in cross-section of the pressure channels.

FIG. 2 shows a modification of the scroll compressor according to FIG. 1. In the modified exemplary embodiment shown in FIG. 2, the mixing chamber 105 is omitted. The high-pressure duct 104 and the intake duct 103 are connected directly to the counter-pressure chamber 10 via a bore.

3 shows a further modified exemplary embodiment of the scroll compressor according to FIGS. 1 and 2. The actuator elements 101 and 102 are replaced by an actuator element which is formed by a mixing valve 101a. The two inputs of the mixing valve 101a are each with the high pressure channel 104 and the

Suction pressure channel 103 connected. Depending on the valve position of the

Mixing valve 101a generates a medium pressure from the proportional inflows of suction and high pressure at the valve outlet, which is connected to the back pressure chamber 10. The mixing valve 101a is in turn connected to a motor via which the valve position can be adjusted.

By providing the actuator elements 101 and 102 or 101a, the

Contact force of the rotor spiral element 22 can be varied depending on the fluid used or depending on the current operating state of the scroll compressor. In order to allow a more precise setting of the contact pressure, the scroll compressor shown in FIGS. 1 to 3 can be expanded in such a way that a measuring device for determining the contact pressure is integrated in the scroll compressor. 4 to 7 correspondingly modified exemplary embodiments are shown. FIG. 4 shows an exemplary embodiment of a scroll compressor according to the invention, modified from the exemplary embodiment of FIG. 3, in which a sensor element in the form of a pressure sensor 110 is provided. The

Pressure sensor 110 is arranged in the back pressure chamber 10 and is designed to measure the back pressure prevailing in the back pressure chamber 10. The value of the back pressure determined in this way is multiplied by the size of the area of the base plate 22a of the rotor spiral element 22 which is in direct contact with the back pressure chamber 10, that is to say an effective area of the base plate 22a on which the back pressure determined by the pressure sensor 110 acts to the pressing force that acts on the rotor spiral element 22.

Fig. 5 shows a modification of the embodiment of Fig. 1. Here, the sensor element is formed by a force sensor 111, which on the

Rotor spiral element 22 facing away from the end of the drive shaft 23 is arranged. The force sensor 111 is decoupled from the drive shaft 23 or its rotational movement by an axial sliding bearing 112. Since the force sensor 111 is arranged near the axial end of the housing 50 on which the electronics housing 70 is located, this is necessary for the operation of the force sensor 111

Force sensor electronics purple housed in the electronics housing 70.

The force sensor 111 is arranged to measure a force that is in

is directly related to the contact pressure. The force sensor 111 can be formed by a piezoelectric element, in which one

Force and associated deformation of the piezoelectric

Element leads to the occurrence of an electrical voltage, the amount of which is proportional to the amount of deformation. Using a

Corresponding characteristic curve, which can be determined in advance and can be stored in purple in the force sensor electronics, the force acting on the force sensor 111 can be determined, from which the contact pressure can in turn be inferred with a suitable calibration of the system. This modification can

of course also to the embodiment of FIG. 2 or 3

be applied.

6 and FIG. 7 show further possible designs for a force sensor as a modification of the exemplary embodiment from FIG. 1. These modifications can also be applied to the exemplary embodiments of FIGS. 2 or 3. In these modified embodiments, the force sensor 111 is a strain gauge formed, which is attached to the bottom plate 21a of the stator spiral element 21 on the side facing the rotor spiral element 22, see FIG. 6, or on the bottom plate 21a of the stator spiral element 21 on the

Rotary spiral element 22 side facing away, see Fig. 7. Strain gauges change their resistance when deformed. With appropriate calibration, the contact pressure can be determined directly using this sensor arrangement. In principle, it is also possible to use piezoelectric elements as force sensors at the positions shown in FIGS. 6 and 7.

With the embodiments shown in FIGS. 4 to 7, the

Determine the pressing force with which the rotor spiral element 22 is pressed against the stator spiral element 21. The pressing force determined in real time can now be used as a control variable in a control circuit in order to control the actuator elements in such a way that the pressing force is set to a predetermined value in order to achieve the optimum contact pressure at any operating point or load point of the scroll compressor Adjust actuator elements controllable back pressure. The control circuit required for this is not shown in FIGS. 4 to 7. It can be present in the electronics housing 70 or can be accommodated in a separate control device. Alternatively, the control circuit can also be present in an existing vehicle intelligence, if the

Scroll compressor is used in a car.

Fig. 8 shows a section of a scroll compressor according to a second

Embodiment of the present invention. The exemplary embodiment in FIG. 8 differs from the exemplary embodiments shown in FIGS. 1 to 7 in the constructive solution for generating the contact pressure. Same

Components are identified by the same reference symbols and are not described in more detail below. Instead, the description focuses on the differences from the first embodiment and its

Modifications.

The drive shaft in 23 in Fig. 8 serves as in the previous ones

Embodiments of generating the orbiting movement of the

Rotor spiral element 22. The drive shaft 23 according to the present

Embodiment is mounted in the scroll compressor movable in the axial direction. This can be achieved, for example, in that the bearings 24a, 24b are designed as floating bearings. The compressor feed line 27, the Suction area 30 fluidly connects to the compressor unit 20 is also provided. The suction pressure and high pressure channels, however, are not available. In this exemplary embodiment, the contact pressure is generated in that an actuator 120 is provided which is designed to generate a

To exert pressure force on the drive shaft 23 in the axial direction in order to press the rotor spiral element 22 against the stator spiral element 21.

8, the actuator 120 is arranged on the axial end of the drive shaft 23 facing away from the compressor unit 20. The actuator 120 is of the

Rotational movement of the drive shaft 23 is decoupled by a slide bearing 112 or a comparable measure. Actuator electronics 112a, which is required for actuating the actuator 120, are in the electronics housing 70

arranged.

The integration of the actuator 120 along the axis of rotation of the drive shaft 23 makes it possible to convert a control signal for the actuator 120 into mechanical movement. The movement of the actuator 120 is transmitted to the drive shaft 23. The contact pressure between the rotor spiral element 22 and the stator spiral element 21 can thus be generated via the mechanical movement of the actuator 120.

In general, 120 versions are possible for the actuator that directly

Transfer actuator movement to the drive shaft 23. In this case, the actuator 120 can be formed, for example, by a stepper motor with a plunger.

Alternatively, it is possible to couple the actuator 120 to the drive shaft 23 via a lever or a gear, in particular also with an over or

Reduction.

An advantage of the generation of contact pressure by an actuator 120 acting on the drive shaft 23 is that no return of already compressed fluid from the high pressure region 40 back into the

Compression process takes place. The leakage current of the fluid to be compressed can thus be significantly reduced, which increases the volumetric efficiency of the scroll compressor.

FIG. 9 shows a modification of the scroll compressor according to FIG. 8. Here is an at the axial end of the drive shaft 23 on which the actuator 120 is arranged Stop 113 is provided, which limits the movement of the drive shaft 23 in the axial direction, regardless of a minimal actuator movement. Various actuators do not behave linearly with their actual working area with a minimal degree of control. Because the actuator 120 must first carry out a certain stroke or a certain movement before it touches the drive shaft 23, it comes into its linear effective range, which enables precise and reproducible control. In order to prevent damage to the scroll compressor during this process, the stop 113 is provided for the drive shaft. 9 also illustrates a coupling of the actuator 120 to the drive shaft 23 via a gear 122.

Fig. 10 shows a scroll compressor with an alternative design of the actuator 120. In addition to actuators in the usual sense for the application of the pressing force is also the generation of an axial force on the drive shaft 23 with a

Magnetic field possible. The drive shaft 23 acts as an armature in a coil 130. The electronics of the coil 130 can in turn be accommodated in the electronics housing 70 in this embodiment. The corresponding deflection of the drive shaft 23 can be excited via the energization of the coil 130, which in turn generates the contact pressure between the rotor spiral element 22 and the stator spiral element 21. Spacers 131 can be provided for mounting and for adjusting a distance between the drive shaft 23, which acts as a rotor, and the coil 130.

As in the first exemplary embodiment and its modifications according to FIGS. 1 to 7, it makes sense in the second exemplary embodiment, in which the contact pressure is generated by the actuator 120 acting on the drive shaft 23, to determine the actual value of the current contact pressure. This is illustrated by way of example in FIG. 11, which shows a modification of the scroll compressor according to FIG. 8. A force sensor 121 is between the actuator 120 and the

Drive shaft 23 arranged and measures the force applied to the drive shaft 23 by the actuator 120. Required for the force sensor 121

Force sensor electronics 121a can in turn be arranged in electronics housing 70.

The contact pressure determined by the force sensor 121 can be used in a control circuit analogously to the first exemplary embodiment and its modifications, in order to make the contact pressure dependent on the current one Optimally set operating conditions and conditions of the scroll compressor. The positions and designs of the force sensor shown in FIGS. 6 and 7 can also be used for this purpose.

FIG. 12 shows a modification of the scroll compressor according to FIG. 11. Here, an oil return actuator element 61 is provided in the oil return 60. By using the oil return actuator element 61 in the oil return 60, analogously to the actuator elements in the pressure channels of the first exemplary embodiment, the cross section of the oil return 60 can be varied and the return of the oil can thus be configured actively and independently of a load point.

Basically, the same can be used as the oil return actuator element 61

Actuator elements are used which are also used in actuator elements 101, 102 of the first exemplary embodiment. Alternatively, the use of a solenoid valve is also possible, which is only the open or the

can assume a closed position, but with which the oil quantity can be regulated via the clock frequency of the opening and closing commands.

In order to be able to control the oil return more precisely, can also for the

A corresponding control can be provided in the oil return actuator element 61. For this purpose, the amount of oil in the high-pressure area 40 or a measurement variable proportional to it must be available. 13 shows a corresponding one

Modification of the exemplary embodiment from FIG. 12. To determine the amount of oil in the high-pressure region, a fill level sensor 62 is arranged at the lower end of the oil separation chamber 42, with which the amount of oil in the

Oil separation chamber 42 separated oil can be determined. On the basis of these measured values, the oil return can be regulated by controlling the oil return actuator element 61. This means that an optimal amount of circulating oil can be set, which in turn can contribute to an increase in efficiency.

In principle, an internal fluid leakage flow also occurs via the oil return 60. By closing the oil return 60 by means of the

Oil return actuator element 61 can be avoided. The only requirement is that a sufficient amount of oil returns from the compression circuit via the suction side, so that lubrication and sealing within the compressor unit 20 is ensured. FIG. 14 shows a modification of the scroll compressor according to FIG. 13. In addition to the sensor system described in the previous exemplary embodiments, a speed sensor 123 is provided in this exemplary embodiment, which measures the speed of the drive shaft 23. The speed sensor 123 can be arranged on the axial end of the drive shaft 23, on which the actuator 120 is also located. Alternatively, as shown in FIG. 14, the speed sensor 123 can also be provided on the end of the suction region 30 facing the compressor unit 20. Here, the speed sensor 123 can either on the outer surface of the

Drive shaft 23 may be aligned or alternatively axially on the top surface of the rotor 24. An incremental encoder with optical or magnetic mode of action can be used as the speed sensor 123, for example.

Speed sensor electronics 123a required for the operation of the speed sensor 123 can in turn, as shown in FIG. 14, be accommodated in the electronics housing 70.

With the speed sensor 123, the instantaneous speed of the drive shaft 23, and thus also a rotational nonuniformity of the drive shaft 23, which may arise due to the compression process, can be detected. The

Knowledge of the function with which the rotational nonuniformity

Compression process follows, or when there is a maximum or a minimum of rotational nonuniformity, allows measures to actively influence or compensate for these irregular rotational movements. For this purpose, the determined speed in the control of the contact pressure can be adjusted accordingly

be taken into account. For example, a falling speed can be compensated for by reducing the pressing force and vice versa.

An advantage of controlling the contact pressure taking into account the rotational speed or rotational non-uniformity is that the generation of vibrations in the scroll compressor can be prevented by reducing the rotational non-uniformity. When using the scroll compressor in a car, the entry of vibrations into the vehicle can be reduced or reduced.

In order to optimize the operating state of the scroll compressor even more thoroughly, the speed of the drive shaft 23 can also be varied in that the energization of the motor driving the drive shaft 23, ie the energization of the stator 25 is controlled, in particular as a function of the speed or rotational irregularity determined by the speed sensor 123. Falling speeds can be compensated for by increasing the drive current for the stator 25 and vice versa. The control of the electric motor with the stator 25 can also be done in combination with the control of the pressing force.

FIG. 15 shows a modification of the scroll compressor according to FIG. 14. In addition to the speed sensor 123, a high-pressure sensor 124 is provided, which is designed to measure the pressure prevailing in the compressor unit 20. The high pressure sensor 124 is immediately adjacent to the hot gas valve 26

arranged to the pressure of the maximum compressed fluid in the

Compressor unit 20 to measure.

The combination of the high pressure sensor 124 with the speed sensor 123 and / or the force sensor 121, and the possibility of controlling the

The pressing force and / or the speed of the drive shaft 23 enable a large number of control scenarios with which the operation of the scroll compressor can be optimized with regard to various aspects.

According to the present exemplary embodiment, improved compensation for the rotational irregularity is possible, for example. Will the

Rotational non-uniformity detected by the detection of the speed sensor 123, the phenomenon can be counteracted in such a way that the rotating field, which sets the drive shaft 23 in rotation, is weakened as soon as, for example, the compression has taken place and the torque load on the

Drive shaft 23 decreases briefly until the next pressure maximum. This is accomplished by appropriate control of the drive current for the stator 25.

The high-pressure sensor 124 is arranged in front of the hot gas valve 26 in relation to the direction of flow of the fluid to be compressed and supplies a pressure signal. This pressure signal can be used to counter the sudden increase in the drive shaft speed after opening the hot gas valve 26 due to constant electrical drive power with reduced mechanical resistance in the compressor unit 20. This can actively reduce rotary shocks that occur when the Scroll compressor occur. The control used for this purpose can in particular be designed as a self-learning controller with combined feedback / feed forward control.

The relationship between how the rotating field depends on the

Compression process can also be developed using a

corresponding control circuit, which is controlled in its own

Control unit or can be present in an existing vehicle intelligence.

The speed sensor 123 can also be used for more extensive

Use control processes in the scroll compressor. For example, the energization of the electric motor driving the drive shaft 23 can be interrupted if the rotational speed exceeds a preset limit value. A shutdown of the scroll compressor can also be set if the high-pressure sensor 124 measures a pressure value in the compressor unit 20 that lies above a preset high-pressure limit value. Damage to the scroll compressor can thus be effectively suppressed.

In connection with the foregoing, the

Contact pressure can be controlled depending on the angle of rotation. As

Input variable of the control can also be used the pressure value determined by the high pressure sensor 124 upstream of the hot gas valve 26. Depending on

Pressure curve during a working cycle in the course of one revolution of the

Rotor spiral element 22, the pressing force can be controlled or readjusted. With the help of a prematurely falling high pressure, an internal leak due to insufficient contact pressure can be detected and avoided at the next cycle.

There are also operating conditions in which the scroll compressor is exposed to high unwanted loads. This includes, for example, the scenario that the fluid condenses and collects in the scroll compressor if, for example, the scroll compressor is exposed to a cold ambient temperature. In this case, the scroll compressor is full of liquid fluid. Will the

If the scroll compressor is started under these conditions by energizing the stator 25, it may happen that the scroll compressor cannot displace the liquid fluid and therefore does not start. In this situation, the scroll compressor according to the present

Embodiment by means of the actuator 120, the rotor spiral element 22 can be moved in a targeted manner in the direction of the suction region 30 and thus a desired internal leakage is generated in the compressor unit 20. This enables the scroll compressor to start. As soon as the scroll compressor has started up, the rotor spiral element 22 can be brought into tight axial engagement with the stator spiral element 21 again by means of the actuator 120 and the compression operation can be started again. The application of the contact pressure can be time or pressure controlled.

With the above measures, start of the

Scroll compressor can be ensured even when the fluid is in an unfavorable state of aggregation, the maximum current consumption of the scroll compressor is also reduced, and the load on the materials is reduced and the service life of the scroll compressor is increased.

FIG. 16 shows a modification of the scroll compressor from FIG. 15. In addition, a temperature sensor 125 is provided, which is designed to measure a temperature of the fluid in the high-pressure region. Preferably, the

Temperature sensor 125 in the immediate vicinity of the output of the

Hot gas valve 26 attached.

When using the temperature sensor 125, the aggregate state of the fluid in the high-pressure region 40 can be determined, taking into account corresponding material data that are stored on a control unit. In this way, it can be determined when liquid fluid is present in the compressor unit 20 or the high pressure region 40 adjoining it. Accordingly, the control of that described with reference to FIG. 15 can be performed

Startup behavior of the scroll compressor can be controlled even more reliably.

The temperature sensor 125 can of course also be used as another

Use safety device. If the maximum temperature of the fluid to be compressed, which occurs immediately after the outlet of the compressor unit 20, is known, the scroll compressor can be switched off when a preset maximum temperature is reached. In addition, the possibility of pushing the drive shaft 23 axially in the direction of the electronics housing and thus causing a targeted leakage in the axial direction in the compressor unit 20 can suddenly supply a large amount of cold suction gas to the hot fluid in the compressor unit 20 due to the axial leakage , This can cause damage to the

Complete failure of the scroll compressor can be avoided.

The control measures described above can be combined with one another in a suitable manner in order to optimally adapt the control of the scroll compressor to given conditions. Since the principle of operation of the scroll compressors for applications in the automotive sector and in stationary technology is basically the same, all of the features described here could be used both in a scroll compressor for cars and also applied to stationary technology.

The exemplary embodiments described above can be combined with one another with regard to the features described. In particular, the modifications of the scroll compressor according to the second exemplary embodiment, which are shown in FIGS. 9 to 16, can also be applied to the scroll compressor according to the first

Embodiment can be applied.

LIST OF REFERENCE NUMBERS

10 back pressure chamber

20 compressor unit

21 stator spiral element

22 rotor spiral element

21a, 22a base plate

21b, 22b spiral wall

23 drive shaft

23a-c bearings

24 rotor

25 stator

6 hot gas valve

27 Compressor supply line 0 Intake area 0 High pressure area

1 high pressure chamber

2 oil separation chamber 3 overflow channel

4 immersion tube 0 housing

1 fluid inlet

2 fluid outlet 0 oil return

1 oil return actuator element 2 level sensor 0 electronics housing

101 first actuator element

101a mixing valve

102 second actuator element 103 suction pressure channel

104 high pressure duct

105 mixing chamber

110 pressure sensor

111 force sensor

l i la force sensor electronics

112 plain bearings

113 stop

120 actuator

120a actuator electronics

121 force sensor

121a force sensor electronics

122 gearbox

123 speed sensor

123a speed sensor electronics

124 high pressure sensor

125 temperature sensor

130 spool

Z cylinder axis

Claims

Expectations

1. Scroll compressor, comprising:

- A compressor unit (20) with a fixed

Stator spiral element (21) and a rotatable, relative to

Stator spiral element (21) axially movably mounted

Rotor spiral element (22), wherein the compressor unit (20) is designed to draw in a fluid to be compressed from a suction region (30), to compress it and to convey it to a high pressure region (40);

- A counter pressure chamber (10) which is arranged on a side of the rotor spiral element (22) facing away from the stator spiral element (21) and can be acted upon with a counter pressure in order to exert a pressing force in the axial direction on the rotor spiral element (22) and that

To press the rotor spiral element (22) against the stator spiral element (21); wherein there is a fluid connection between the back pressure chamber (10) and the suction area (30), and wherein there is a fluid connection between the back pressure chamber (10) and the high pressure area (40); - A suction pressure channel (103) which is arranged in the fluid connection between the back pressure chamber (10) and the suction area (30);

- A high pressure channel (104) which is arranged in the fluid connection between the back pressure chamber (10) and the high pressure area (40); wherein in the high pressure channel (104) and the suction pressure channel (103) at least one actuator element (101, 102, 101a) is arranged, by means of which the cross section of the high pressure channel (102) and the

Suction pressure channel (103) is changeable.

2. Scroll compressor according to claim 1, wherein the actuator element (102) of the

High-pressure channel (104) and / or the actuator element (101) of the

Suction pressure channel (103) through an actuator with an orifice geometry, a needle valve, a ball valve, a throttle valve or

Shape memory wire is formed.

3. Scroll compressor according to claim 1, wherein the actuator element of the

High-pressure channel (104) and the actuator element of the suction pressure channel (103) is formed by a mixing valve (101a) which is connected to the high-pressure channel (104), the suction pressure channel (103) and the back pressure chamber (10).

4. Scroll compressor according to one of the preceding claims, comprising a sensor element which is designed to measure a measurement variable from which the contact pressure which can be generated by the counterpressure in the counterpressure chamber (10) can be determined.

5. Scroll compressor according to claim 4, wherein the sensor element is formed by a pressure sensor (110) which is designed to measure the back pressure prevailing in the back pressure chamber (10).

6. Scroll compressor according to claim 4, wherein the sensor element is formed by a force sensor (111) which is attached to a drive shaft (23) connected to the rotor spiral element (22), the rotor spiral element (22) or the stator spiral element (21).

7. Scroll compressor according to one of the preceding claims, in particular according to claim 4 to 6, comprising a control unit, which

is designed to control the at least one actuator element (101, 102, 101a) in such a way that the contact pressure that can be generated by the counter pressure in the counter pressure chamber (10) can be controlled, in particular as a function of the contact force determined by means of the sensor element.

8. Scroll compressor, having;

- A compressor unit (20) with a fixed

Stator spiral element (21) and a rotatable, relative to

Stator spiral element (21) axially movably mounted

- A drive shaft (23) which is coupled to the rotor spiral element (22) on a side facing away from the stator spiral element (21) in order to transmit a rotational movement to the rotor spiral element (22) and which is movably mounted in the axial direction;

- An actuator (120) which is designed to exert a pressing force on the drive shaft (23) in the axial direction in order to

Press the rotor spiral element (22) against the stator spiral element (21).

9. Scroll compressor according to claim 8, wherein the actuator (120) by a

piezoelectric element is formed.

10. Scroll compressor according to claim 8 or 9, comprising a sensor element which is designed to measure a measured variable from which the contact pressure force which can be generated by the actuator can be determined.

11. Scroll compressor according to claim 10, wherein the sensor element is formed by a force sensor (121) on the drive shaft (23)

Stator spiral element (21) or the rotor spiral element (22)

is appropriate.

12. Scroll compressor according to one of claims 8 to 11, in particular according to claim 10 or 11, comprising a control unit which is designed to control the actuator, such that the contact force which can be generated by the actuator can be controlled, in particular as a function of the means contact pressure determined by the sensor element.

13. Scroll compressor according to one of the preceding claims, comprising an oil return (60), which is a fluid connection between the

High-pressure area (40) and the suction area (30) forms in order to return oil located in the high-pressure area (40) to the suction area (30), wherein an oil return actuator element (61) is arranged in the oil return (60), by means of which the cross section the oil return (60) can be changed,

14. Scroll compressor according to claim 13, comprising a fill level sensor (62), which is designed to measure an oil fill level in the high pressure region (40).

15. Scroll compressor according to claim 13 or 14, in particular according to claim 14, comprising an oil return control unit which is designed to control the oil return actuator element (61), in particular as a function of that determined by means of the fill level sensor

Oil level.

16. Scroll compressor according to one of the preceding claims, comprising a speed sensor (123) which is designed to measure a speed of the rotor spiral element (22).

17. Scroll compressor according to claim 16, comprising one

Rotary drive control, which is designed to control a rotary drive of the rotor spiral element (22) as a function of the speed determined by means of the speed sensor.

18. Scroll compressor according to claim 17, comprising a high pressure sensor (124), which is designed to measure a pressure in the compressor unit (20).

19. ScroII compressor according to claim 18, wherein the rotary drive control is designed to control the control of the rotary drive as a function of the pressure in the compressor unit (20).

20. ScroII compressor according to one of the preceding claims, comprising a temperature sensor (125) which is designed to measure a temperature of the fluid to be compressed in the high-pressure region (40), preferably directly at an outlet of the compressor unit (20).

21. ScroIIverdichter according to any one of the preceding claims, wherein the control unit is designed to the contact pressure depending on the speed and / or the instantaneous rotation angle and / or the pressure in the compressor unit (20) and / or the temperature of the

to control compressing fluids in the high pressure region (40).