EP3516225A1

EP3516225A1 - Screw compressor system for a utility vehicle

Info

Publication number: EP3516225A1
Application number: EP17777198.7A
Authority: EP
Inventors: Gilles Hebrard; Jean-Baptiste Marescot; Jörg MELLAR; Thomas Weinhold
Original assignee: Knorr Bremse Systeme fuer Nutzfahrzeuge GmbH
Current assignee: Knorr Bremse Systeme fuer Nutzfahrzeuge GmbH
Priority date: 2016-09-21
Filing date: 2017-09-19
Publication date: 2019-07-31
Also published as: CN109964037A; DE102016011508A1; US20190376517A1; CN109964037B; WO2018054879A1; BR112019005118A2; JP6896083B2; KR20190047725A; JP2019536943A

Abstract

The invention relates to a screw compressor system (100) for a utility vehicle, comprising at least one screw compressor (10), at least one screw compressor drive, at least one temperature probe (38) and at least one control and regulation unit (110). Said control and/or regulation unit (110) is connected to the screw compressor drive and to the temperature probe (38) and is designed and configured such that it controls, in accordance with a temperature threshold signal obtained from the temperature probe (38), the screw compressor drive with respect to a rotational speed.

Description

DESCRIPTION

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

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 poses the task, the

To regulate oil temperature. This is usually accomplished by having an external oil cooler, the compressor filled with the oil and the

Oil circuit is connected via a thermostatic valve. The oil cooler is here

Heat exchanger having 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 with the compressor oil circuit through pipes or

Hoses are connected and the oil circuit must be secured against leaks.

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

Holder, which requires additional means of improvement, but also space. From US 4,780,061 a screw compressor with an integrated oil cooling is already known. Furthermore, the DE 37 17493 A1 discloses a 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 already known, for example, from DE 10 2004 060417 [34.

It is the object of the present invention to further develop a screw compressor system of the type mentioned in an advantageous manner, in particular

in that the drive control and / or regulation of the

Screw compressor simplified and can be configured reliably.

This object is achieved by a screw compressor for a commercial vehicle with the features of claim 1. Thereafter, it is provided that a screw compressor for a commercial vehicle at least one

Screw compressor, at least one screw compressor drive, at least one temperature sensor and at least one control and / or regulating unit, wherein the control and / or regulating unit with the

Screw compressor drive and the temperature sensor is in communication, wherein the control and / or regulating unit is arranged and configured such that in response to a Temperaturschwellwertsignal received from the temperature sensor drives the screw compressor drive in terms of its speed.

The invention is based on the idea that a temperature management of the screw compressor system can be achieved in that the screw compressor drive is dependent on the temperature in the screw compressor

is controlled accordingly. The speed of the screw compressor drive also significantly affects the temperature of the screw compressor. If you reach a certain temperature, so by adjusting the speed of the Screw compressor drive the temperature increased or decreased accordingly. In particular, it can be provided that the

Screw compressor system is comparatively large, so that due to the amount of oil present in the screw compressor, there is a certain inertia that it comes to temperature changes. It is also conceivable that it is a screw compressor system, which is usually designed for a part-load operation or a low-load operation and which does not have to run constantly in full load operation. For example, it can be provided that the control and / or regulating unit is part of the screw compressor system. 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. Again, 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.

In addition, it can be provided that the control and / or

Control unit is designed and configured such that it upon receipt of a temperature threshold signal that exceeds a certain

Temperature threshold in the screw compressor signals the

Screw compressor drive shuts off. As a result, a temperature reduction in the screw compressor can be achieved easily and effectively in a very short time. Without operation of the screw compressor, which by switching off the

Screw compressor drive is achieved, there is no further

Heat development more in the screw compressor, so that it can cool down. Furthermore, it is conceivable that the control and regulating unit is designed and configured such that it switches on the

Screw compressor drive only allows when they enter

Temperaturschwellwertsignal receives, which signals a falling below a predetermined temperature threshold in the screw compressor. In principle, the temperature threshold signal, which falls below a predetermined

Temperature threshold signaled in the screw compressor, differ from a temperature threshold signal, which receives the control and / or regulating unit, with which a shutdown of the screw compressor drive is triggered. These temperature threshold signals can also be identical. By preventing a start-up or restart of the screw compressor at too high a temperature is also simple but reliable control of the temperature in the rob or compressor system in the

Screw compressor allows. It may be provided that the screw compressor system no

Thermostatic valve has. Basically, it is conceivable that due to the design of the control and / or regulating unit, the temperature management of the

Screw compressor can be operated so effectively that no heat-dependent connection of an oil cooling circuit is required, which usually has a thermostatic valve. This component of the screw compressor system can thus be omitted.

In principle, it can also be provided that the

Screw compressor system has no heat exchanger for oil cooling. By omission of this comparatively expensive component, the overall structure of the

Screw compressor system can be simplified. 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:

Fig. 1 is a schematic sectional view through an inventive

Screw compressor; and

Fig. 2 is a schematic drawing of the screw compressor system according to the present invention.

Fig. 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 attachment of the screw compressor 10 to an electric motor not shown here.

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

The screw 18 meshes with the screw 16 and is driven by this.

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

The housing 20 is filled with oil 22.

Air inlet side is on the housing 20 of the screw compressor 10 a

Inlet port 24 is provided. The inlet nozzle 24 is designed such that an air filter 26 is arranged on it. In addition, an air inlet 28 is provided radially on the air inlet pipe 24. In the area between inlet port 24 and the Steep, where the inlet port 24 attaches to the housing 20, a spring-loaded valve core 30 is provided, designed here as an axial seal. This valve insert 30 serves as a check valve.

Downstream of the valve core 30, an air supply channel 32 is provided, which supplies the air to the two screws 16, 18. On the output side of the two screws 16, 18, an air outlet pipe 34 is provided with a riser 36.

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

Furthermore, a holder 40 for an air de-oiling element 42 is provided in the air outlet area.

The holder 40 for the air de-oiling element has in the assembled state in the area facing the bottom (as shown in Fig. 1), the air de-oiling element 42.

Further provided in the interior of the air de-oiling element 42 is a corresponding filter screen or known filter and oil-separating devices 44, which are not specified in detail. In the central upper area, relative to the assembled and ready-to-use state (ie as shown in FIG. 1), the holder for the air de-oiling element 40 has a

Air outlet opening 46, leading to a check valve 48 and a

Minimum pressure valve 50 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, the air outlet 51 is provided. The air outlet 51 is connected to correspondingly known compressed air consumers in the rule.

In order to return the oil 22 located and separated in the air de-oiling element 42 back into the housing 20, a riser 52 is provided, the outlet of the holder 40 for the Luftentölelement 42 when passing into the housing 20 has a filter and check valve 54.

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

In the assembled state located in the bottom portion of the housing 20 is a

Oil drain plug 59 is provided. About the oil drain plug 59, a

corresponding oil drain opening are opened, via which the oil 22 can be drained.

In the lower region of the housing 20 and the projection 60 is present, to which the oil filter 62 is attached. Via an oil filter inlet channel 64, which is arranged in the housing 20, the oil 22 is first passed to a thermostatic valve 66.

Instead of the thermostatic valve 66, a control and / or

Regulation means may be provided by means of which the Öitemperatur located in the housing 20 oil 22 can be monitored and adjusted to a desired value.

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

The cooler 74 is connected to the projection 60, as will be explained in more detail below in FIGS. 2 to 4. In the upper region of the housing 20 (relative to the mounted state) there is a safety valve 76, via which an excessive pressure in the housing 20 can be reduced.

Before the minimum pressure valve 50 is a bypass line 78, which leads to a relief valve 80. About this relief valve 80 by means of a

Connection with the air supply 32 is controlled, air can be returned to the region of the air inlet 28. 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, approximately at the level of the conduit 34 in the outer wall of the housing 20, an oil level sensor 82 may be provided. This oil level sensor 82 may be, for example, an optical sensor and arranged and set up so that it can be detected by the sensor signal, whether the oil level is above the oil level sensor 82 in operation or if the oil level sensor 82 is exposed and thereby 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 the screw compressor 10 shown in FIG. 1 is as follows:

Air is supplied via the air inlet 28 and passes through the check valve 30 to the screws 16, 18, where the air is compressed. The compressed air-oil mixture, which rises by a factor of between 5 and 16 times compression after the screws 16 and 18 through the outlet conduit 34 via the riser 36, is blown directly onto the temperature sensor 38. The air, which still partially carries oil particles, is then passed over the holder 40 in the Luftentölelement 42 and, provided the corresponding minimum pressure is reached, in the Luftauslassleitung 51. The oil 22 located in the housing 20 is above the oil filter 62 and possibly. kept at operating temperature via the heat exchanger 74.

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

The corresponding connection takes place via the thermostatic valve 68. After the purification in the oil filter 64, oil is supplied via the line 68 to the screw 18 or the screw 16, but also to the bearing 72. The screw 16 or the screw 18 is fed via the return line 52, 58 Oil 22 supplied, here is the purification of the oil 22 in the air de-oiling 42nd

About the electric motor not shown in detail, which transmits its torque via the shaft 14 to the screw 16, which in turn meshes with the shaft 18, the screws 16 and 18 of the screw compressor 10 are driven.

About the relief valve 80 is not shown in detail ensures that in the supply line 32 is not the high pressure prevailing in the operating state, for example, the output side of the screws 16, 18, can be locked, but that in particular at the start of 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 arise on the output side of the screws 16 and 18, which would overload the drive motor.

Fig. 2 shows a schematic representation of an inventive

Screw compressor system 100 with the screw compressor 10 shown in FIG. The screw compressor system 100 further includes a control and / or regulating unit 110 which is connected to the temperature sensor 38 and the drive of the screws 16 and 18 of the screw compressor 10 (the electric motor, not shown, which transmits its torque to the input shaft 14) Connection stands.

The control and regulation unit 110 is here as part of the

Screw compressor 10 is formed.

In principle, however, it can be provided that the control and regulation unit 1 0 part of an air treatment system of the not shown

Commercial vehicle, part of an engine or vehicle control of the commercial vehicle or as a separate control and regulation unit 110 is formed.

The control unit 110 is arranged and configured to receive, in response to a temperature threshold signal

Temperature sensor 38 controls the screw compressor drive in terms of its speed.

It is provided in particular that the control and regulation unit 110 upon receipt of a temperature threshold signal that exceeds the

predetermined temperature threshold signal in the screw compressor 10, the screw compressor drive shuts off.

A startup of the screw compressor is only possible again when a temperature threshold signal is transmitted from the temperature sensor 38 to the control and regulation unit 110, which signals a falling below a predetermined temperature threshold in the screw compressor 10.

The temperature threshold for turning the power on and off

Screw compressor 10 is preferably chosen to be identical in order to allow a simple implementation. In principle, however, it can also be provided that different threshold values are provided for this purpose.

The temperature threshold may be selected, for example, at about 10 to 30% above the normal operating temperature.

Due to the embodiment shown in Fig. 2, it is possible that the

Screw compressor system 100 and the screw compressor 10 no thermostatic valve 66 and no heat exchanger 74 must have more.

LIST OF REFERENCE NUMBERS

10 screw compressor

12 mounting flange

14 input shaft

16 screws

18 screws

20 housing

22 oil

24 inlet ports

26 air filters

28 air intake

30 valve insert

32 air supply duct

34 air outlet pipe

36 riser

38 temperature sensor

40 holder for an air de-oiling element

42 air deoiling element

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 nozzle

58 Oil return line

59 Oil drain plug

60 approach

60a outer ring

60b inner ring

62 oil filter 64 oil filter inlet channel

66 thermostatic valve

68 return line

70 bearings

72 nozzle

74 coolers, heat exchangers

76 safety valve

78 Bypass loading

80 relief valve

82 oil level sensor

100 screw compressor system

110 control and / or regulating unit

Claims

A screw compressor system (100) for a utility vehicle having at least one screw compressor (10), at least one screw compressor drive, at least one temperature sensor (38) and at least one control and / or regulating unit (110), wherein the control and / or regulating unit (110 ) is in communication with the screw compressor drive and the temperature sensor (38), wherein the control and / or regulating unit (110) is adapted and configured to drive the screw compressor drive in response to a temperature threshold signal received from the temperature sensor (38) ,

2. Screw compressor system (100) according to claim 1,

characterized in that

the control and / or regulating unit (110) is part of the

Screw compressor (10) is

3. screw compressor system (100) according to claim 1,

characterized in that

the control and / or regulating unit (110) is part of a

Air treatment system of the commercial vehicle is.

4. screw compressor system (100) according to claim 1,

characterized in that

the control and / or regulating unit (110) part of an engine or

Vehicle control of the commercial vehicle is.

5. screw compressor system (100) according to claim 1,

characterized in that

the control and / or regulating unit (110) is a separate control and / or regulating unit (110).

6. Screw compressor system (100) according to one of the preceding claims, characterized in that

the control unit (110) is arranged and configured to shade the screw compressor drive upon receipt of a temperature threshold signal indicative of exceeding a predetermined temperature threshold in the screw compressor (10).

7. screw compressor system (100) according to one of the preceding claims, characterized in that

the control and / or regulating unit (110) is designed and configured such that it only enables the screw compressor drive to be switched on if it receives a temperature threshold signal which signals that the temperature threshold in the screw compressor (10) has fallen below a predetermined temperature threshold.

8. screw compressor system (100) according to one of the preceding claims, characterized in that

the screw compressor system (100) has no thermostatic valve (66).

9. screw compressor system (100) according to one of the preceding claims, characterized in that

the screw compressor system (100) does not have a heat exchanger (74) for oil cooling.