DE102016011507A1 - Screw compressor system for a commercial vehicle - Google Patents

Abstract

The present invention relates to a screw compressor system (100) for a commercial vehicle with at least one screw compressor (10), at least one screw compressor drive and at least one control and / or regulating unit (110), wherein the control and / or regulating unit (110) with the screw compressor drive is in communication, wherein the control and / or regulating unit (110) is such and configured to monitor the operation of the screw compressor (10), the ratio of service life and on time of the screw compressor drive and this ratio controls on a predetermined range and / or adjusts.

Description

The present invention relates to a screw compressor system for a commercial vehicle with at least one screw compressor with at least one control and / or regulating unit for drive control and / or regulation of the screw compressor.

Screw compressors for commercial vehicles are already known from the prior art. Such screw compressors are used to provide the necessary compressed air for, for example, the braking system of the commercial vehicle.

In this context, in particular oil-filled compressors, especially screw compressors are known in which the task is to regulate the oil temperature. This is usually done by having an external oil cooler connected to the oil-filled compressor and the oil circuit via a thermostatic valve. The oil cooler is a heat exchanger which has two separate circuits, wherein the first circuit for the hot liquid, so the compressor oil is provided and the second for the cooling liquid. As a coolant, for example, air, water mixtures can be used with an antifreeze or other oil.

This oil cooler must then be connected to the compressor oil circuit via pipes or hoses and the oil circuit must be secured against leakage.

This external volume must also be filled with oil, so that the total amount of oil is increased. This increases the system inertia. In addition, the oil cooler must be mechanically housed and secured, either by surrounding brackets or by a separate bracket, which requires additional means of improvement, but also space.

From the US 4,780,061 already a screw compressor with integrated oil cooling is known.

Furthermore, the DE 37 17 493 A1 an arranged in a compact housing screw compressor system having an oil cooler on the electric motor of the screw compressor.

A generic screw compressor is for example already out of the DE 10 2004 060 417 B4 known.

It is the object of the present invention to develop a screw compressor system of the type mentioned in an advantageous manner, in particular to the effect that the drive control and / or regulation of the screw compressor can be simplified and configured reliably.

This object is achieved by a screw compressor with the features of claim 1. Thereafter, it is provided that a screw compressor for a commercial vehicle with at least one screw compressor, at least one screw compressor drive and at least one control and / or control unit is provided, the control and or control unit is in communication with the screw compressor drive, wherein the control and / or regulating unit is designed and configured so that it monitors the ratio of service life and on time of the screw compressor drive during operation of the screw compressor and controls this ratio to a predetermined range and / or adjusts.

The invention is based on the basic idea that the temperature of the screw compressor is also significantly determined by the ratio of service life and switch-on time. Depending on the design of the screw compressor, it is sufficient to be able to guide the screw compressor in a very narrow operating temperature range by controlling the ratio of service life and switch-on time to a predetermined range. The intermeshing screws and the guided through the screw compressor oil and the compressed air lead to heat generation, so that by appropriate selection of the ratio of service life and on time of the screw compressor drive at the same time the heat of the screw compressor controlled and / or adjusted, d. H. can be adjusted.

For example, it may be provided that the control and / or regulating unit is part of the screw compressor system so either the screw compressor or the screw compressor drive. As a result, a compact structure is formed and it is not necessary to have access to external components.

In principle, however, it is also conceivable that the control and / or regulating unit is part of an air treatment system of the commercial vehicle. Here is already a corresponding control available, which can be easily shared.

It is also conceivable that the control and / or regulating unit is part of an engine or vehicle control of the commercial vehicle. Also Here it would be possible to access an already existing component of the commercial vehicle.

In principle, however, it is also conceivable that the control and / or regulating unit is designed as a separate control and / or regulating unit. This allows for example a simple installation and also a simple exchange or simple upgrades.

Furthermore, it can be provided that the range is selected such that there is a ratio of service life to switch-on time, in which the switch-on time is approximately 20 to 50%, in particular> 30%. This ratio of service life to switch-on time with a switch-on time of between approx. 20 and 40%, in particular> 30%, has proved to be relatively favorable in order to be able to keep the operating temperature substantially constant. In addition, there is the advantage that by ensuring a ratio of service life to switch-on time with a switch-on time of> 30%, the operating temperature remains high enough to reliably avoid moisture or condensation inside the screw compressor.

In addition, it can be provided that the control and / or regulating unit is designed and configured such that it influences the rotational speed of the screw compressor drive in such a way that the ratio of service life and switch-on time of the screw compressor drive is kept within the predetermined range. Essentially, it is assumed here that over the entire running time of the screw compressor a certain amount of compressed air is to be provided and that influenced by the definition or limitation or increase the speed of the screw compressor drive over the entire run time with constant compressed air production and the ratio of service life and on time of the screw compressor drive and so that it can be kept within the given range.

In particular, it may be provided that the control and / or regulating unit is designed and configured such that it always keeps the rotational speed of the screw compressor drive above a minimum rotational speed. This ability to keep the speed above a minimum speed, based on the idea that from a certain minimum speed only a limitation of the power loss occurs and the screw compressor drive requires less energy to produce a certain amount of compressed air. In other words, this can improve the overall efficiency of the screw compressor. For example, it is known that below minimum speeds of about 1,500 to 2,500 revolutions per minute, the power loss can increase sharply, so that falling below these minimum speeds should be avoided if possible.

Further details and advantages of the invention will now be explained in more detail with reference to an embodiment shown in the drawings.

Show it:

1 a schematic sectional view through a screw compressor according to the invention; and

2 a schematic drawing of the Schraubenkompressorsytem according to the present invention.

1 shows a schematic sectional view of a screw compressor 10 in the sense of an embodiment of the present invention.

The screw compressor 10 has a mounting flange 12 for mechanical fastening of the screw compressor 10 on an electric motor not shown here in detail.

Shown, however, is the input shaft 14 , about which the torque from the electric motor on one of the two screws 16 and 18 namely the screw 16 is transmitted.

The screw 18 combs with the screw 16 and is driven by these.

The screw compressor 10 has a housing 20 in which the essential components of the screw compressor 10 are housed.

The housing 20 is with oil 22 filled.

Air inlet side is on the housing 20 of the screw compressor 10 an inlet nozzle 24 intended. The inlet nozzle 24 is designed such that an air filter on it 26 is arranged. There is also a radial air inlet 24 an air intake 28 intended.

In the area between inlet nozzle 24 and the place where the inlet nozzle 24 on the housing 20 attaches, is a spring-loaded valve core 30 provided, designed here as an axial seal.

This valve insert 30 serves as a check valve.

Downstream of the valve core 30 is an air supply duct 32 provided the air the two screws 16 . 18 supplies.

On the output side of the two screws 16 . 18 is an air outlet pipe 34 with a riser 36 intended.

In the area of the end of the riser 36 is a temperature sensor 38 provided, by means of which the oil temperature can be monitored.

Further provided in the air outlet area a holder 40 for an air deoiling element 42 ,

The holder 40 for the air de-oiling element has in the mounted state in the area facing the ground (as well as in 1 shown) the Luftentölelement 42 on.

Next is provided inside the Luftentölelement 42 a corresponding filter screen or known filter and Ölabscheidevorrichtungen 44 , which are not specified in detail.

In the central upper area, relative to the assembled and ready for operation state (ie as in 1 shown), the holder for the Luftentölelement 40 an air outlet opening 46 on that to a check valve 48 and a minimum pressure valve 50 to lead. The check valve 48 and the minimum pressure valve 50 may also be formed in a common, combined valve.

Following the check valve 48 is the air outlet 51 intended.

The air outlet 51 is usually associated with known compressed air consumers.

In the air de-oiling element 42 located and separated oil 22 back in the case 20 due, is a riser 52 provided, the output of the holder 40 for the air deoiling element 42 when crossing into the housing 20 a filter and check valve 54 having.

Downstream of the filter and check valve 54 is a nozzle in a housing bore 56 intended. The oil return line 58 leads back approximately in the middle area of the screw 16 or the screw 18 to this oil again 22 supply.

In the assembled state located bottom portion of the housing 20 is an oil drain plug 59 intended. About the oil drain plug 59 a corresponding oil drain opening can be opened, over which the oil 22 can be drained.

In the lower part of the case 20 is also the approach 60 present, at which the oil filter 62 is attached. Via an oil filter inlet channel 64 in the case 20 is arranged, the oil becomes 22 first to a thermostatic valve 66 directed.

Instead of the thermostatic valve 66 a control and / or regulating device may be provided, by means of which the oil temperature of the housing 20 located oil 22 can be monitored and set to a setpoint.

Downstream of the thermostatic valve 66 is then the oil inlet of the oil filter 62 , which has a central return line 68 the oil 22 back to the screw again 18 or to the screw 16 , but also to the oil-lubricated bearing 70 the wave 14 leads. In the area of the warehouse 70 is also a nozzle 72 provided in the housing 20 in connection with the return line 68 is provided.

The cooler 74 is at the beginning 60 connected, as below in the 2 to 4 is explained in more detail.

In the upper part of the case 20 (based on the assembled state) is a safety valve 76 , over which too much pressure in the housing 20 can be reduced.

In front of the minimum pressure valve 50 there is a bypass line 78 leading to a relief valve 80 leads. About this relief valve 80 this by means of a connection to the air supply 32 Air can be controlled in the area of the air intake 28 to be led back. In this area, a vent valve not shown in detail and also a nozzle (diameter reduction of the feeding line) may be provided.

In addition, it can be approximately at the height of the pipe 34 in the outer wall of the housing 20 an oil level sensor 82 be provided. This oil level sensor 82 For example, it can be an optical sensor and can be designed and set up in such a way that it can be detected on the basis of the sensor signal whether the oil level in operation above the oil level sensor 82 or whether the oil level sensor 82 is free and thus the oil level has fallen accordingly.

In connection with this monitoring, an alarm unit can also be provided which outputs or forwards an appropriate error message or warning message to the user of the system.

The function of in 1 shown screw compressor 10 is as follows:
Air gets over the air intake 28 fed and passes through the check valve 30 to the screw 16 . 18 where the air is compressed. The compressed air-oil mixture, with a factor between 5 to 16 times compression after the screws 16 and 18 through the outlet pipe 34 over the riser 36 ascends, is directly on the temperature sensor 38 blown.

The air, which still partially carries oil particles, is then on the holder 40 in the air deoiling element 42 guided and reaches, if the corresponding minimum pressure is reached, in the air outlet pipe 51 ,

That in the case 20 located oil 22 is over the oil filter 62 and optionally via the heat exchanger 74 maintained at operating temperature.

If no cooling is necessary, the heat exchanger 74 not used and is not switched on.

The corresponding connection is made via the thermostatic valve 68 , After purification in the oil filter 64 is over the line 68 Oil of the screw 18 or the screw 16 but also the camp 72 fed. The screw 16 or the screw 18 is via the return line 52 . 58 with oil 22 supplied, here is the purification of the oil 22 in the air deoiling element 42 ,

About the electric motor, not shown in detail, the torque on the shaft 14 on the screw 16 transmits, in turn, with the wave 18 combs, the screws are 16 and 18 of the screw compressor 10 driven.

About the relief valve not shown in detail 80 will ensure that in the area of the supply line 32 not the high pressure, in the operating state, for example, on the output side of the screws 16 . 18 prevails, can be locked, but that especially when starting the compressor in the supply line 32 always a low inlet pressure, in particular atmospheric pressure exists. Otherwise, with a start-up of the compressor, a very high pressure would initially be present on the output side of the screws 16 and 18 arise, which would overload the drive motor.

2 shows a schematic representation of an inventive screw compressor system 100 with the in 1 shown screw compressor 10 and a control unit 110 ,

The control and regulation unit 110 is here as part of the screw compressor system 100 educated.

In principle, however, it can be provided that the control and regulation unit 110 Part of an air handling system of the commercial vehicle, part of an engine or vehicle control of the commercial vehicle or as a separate control unit 110 is trained.

The control and regulation unit 110 is here designed and configured to operate in the screw compressor 10 the ratio of service life and switch-on time of the screw compressor drive to drive the screws 16 and 18 monitors and regulates this ratio to a predetermined range or regulates.

In this case, this range is selected such that there is a ratio of service life to switch-on time, in which the switch-on time is> 30%. In particular, an area is selected here that is between 30 to 50% on-time, so that the service life is between 50 to 70% and the switch-on time is about 30 to 50%.

With a switch-on time of approx. 30%, the service life is approx. 70%.

In order to be able to keep the ratio of service life to switch-on time also constant, the control unit is 110 further arranged and configured so that it affects the speed of the screw compressor drive with.

It is ensured that by reducing or increasing the speed of the screw compressor drive over the entire operating time, the desired amount of compressed air through the screw compressor 10 is provided, but the ratio of service life and turn-on is maintained.

In order to work economically and energy-efficiently, it will continue to do so through the control and regulation unit 110 the speed is always kept above a minimum speed.

This is based on the realization that below the minimum speed the specific energy consumption of the screw compressor drive (ie eg the amount of energy needed to compress one cubic meter (m ³ ) of air) increases very much. In other words, it is thus avoided that excessive power loss or excessive losses occur.

By keeping constant the ratio of service life to switch-on time is thus achieved overall that over the entire operating life of the screw compressor 10 can be kept relatively constant at an operating temperature.

Keeping the compressor at operating temperature throughout its life safely prevents it from entering the housing 20 of the screw compressor 10 condensation can occur.

Due to the constant operating temperature and holding the screw compressor 10 at operating temperature, a condensation in the housing 20 safely avoided.

LIST OF REFERENCE NUMBERS

10

screw compressor

12

mounting flange

14

input shaft

16

screw

18

screw

20

casing

22

oil

24

inlet port

26

air filter

28

air intake

30

valve core

32

air supply duct

34

air discharge

36

riser

38

temperature sensor

40

Holder for an air de-oiling element

42

exhaust filter

44

Filter screen or known filter or Ölabscheidevorrichtungen

46

Air outlet opening

48

check valve

50

Minimum pressure valve

51

air outlet

52

riser

54

Filter and check valve

56

jet

58

Oil return line

59

Oil drain plug

60

approach

60a

outer ring

60b

inner ring

62

oil filter

64

Oil filter inlet duct

66

thermostatic valve

68

Return line

70

camp

72

jet

76

safety valve

78

bypass line

80

relief valve

82

Oil Level Sensor

100

Screw compressor system

110

Control and regulation unit

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 4780061 [0006]
• DE 3717493 A1 [0007]
• DE 102004060417 B4 [0008]

Claims (8)

Screw compressor system ( 100 ) for a commercial vehicle with at least one screw compressor ( 10 ), at least one screw compressor drive and at least one control and / or regulating unit ( 110 ), the control and / or regulating unit ( 110 ) is in communication with the screw compressor drive, the control and / or regulating unit ( 110 ) is configured and configured in such a way that during operation of the screw compressor ( 10 ) monitors the ratio of service life and on-time of the screw compressor drive and controls this ratio to a predetermined range and / or regulates. Screw compressor system ( 100 ) according to claim 1, characterized in that the control and / or regulating unit ( 110 ) Part of the screw compressor system ( 10 ). Screw compressor system ( 100 ) according to claim 1, characterized in that the control and / or regulating unit ( 110 ) Is part of an air treatment system of the commercial vehicle. Screw compressor system ( 100 ) according to claim 1, characterized in that the control and / or regulating unit ( 110 ) Is part of an engine or vehicle control of the commercial vehicle. Screw compressor system ( 100 ) according to claim 1, characterized in that the control and / or regulating unit ( 110 ) as a separate control and / or regulation unit ( 110 ). Screw compressor system ( 100 ) according to one of the preceding claims, characterized in that the range is selected such that there is a ratio of service life to switch-on time, in which the switch-on time is approximately 20-40%, in particular greater than 30%. Screw compressor system ( 100 ) according to one of the preceding claims, characterized in that the control and / or regulating unit ( 110 ) is configured and configured to influence the rotational speed of the screw compressor drive such that the ratio of service life and on-time of the screw compressor drive is maintained within the predetermined range. Screw compressor system ( 100 ) according to claim 7, characterized in that the control and / or regulating unit ( 110 ) is configured and configured so that it keeps the speed of the screw compressor drive always above a minimum speed.

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