Compressor for Producing Compressed Air, Compressed Air Supply System, Pneumatic System and Method for Operating a Compressor

• US 20150345490A1
• Filed: 10/31/2013
• Published: 12/03/2015
• Est. Priority Date: 12/13/2012
• Status: Active Grant

• Current Assignee: ZF CV Systems Europe BV (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: Wabco GmbH (Wabco Holdings Incorporated)
• Inventors: Meier, Jorg, Sohn, Robert, Stabenow, Uwe, Bremeier, Ralf, Koumenda, Pierre Celestin
• Granted Patent: US 11,156,220 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F04B 49/06 Control using electricity regulating by means of floats actuating electric switches F04B49/04
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04D 27/00 Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
• CPC Class Codes: H02P 1/24 for starting an individual ac commutator motor starting of ac/dc commutator motors H02P1/18

Abstract

A compressor for producing compressed air, in particular for a compressed air supply system of a vehicle, includes an electric motor in the form of a brushed direct current electric motor. The compressor has at least one first and one second compressor step, which can be driven by the electric motor. The motor can be controlled by means of an electronic control module of a control device by limiting an operational flow of the motor.

Claims

1. A compressor for a compressed air supply installation of a vehicle, the compressor comprising:

a brushed DC electric motor; and

a compressor unit driveable by the motor, wherein the motor is controllable by an electronic control module of a control device with limitation of an operating current of the motor, and wherein the electronic control module has a control assembly and an executable program module, and is configured to predefine in chronologically variable manner a threshold current that limits the operating current.

2. The compressor as claimed in claim 1, wherein the compressor unit is a two-stage compressor unit having at least a first and a second compressor stage.

3. The compressor as claimed in claim 1, wherein the program module is configured to predefine at least one threshold current-limiting function of the threshold current as a function of time to limit the operating current, and the control assembly is configured to interrupt operating energy or another operating parameter of the motor.

4. The compressor as claimed in claim 3, wherein at least one of an analysis unit and an actuator system of the control device is configured to test whether the operating current reaches the threshold current of the at least one threshold current-limiting function and to interrupt operating energy after at least one of a predetermined interruption frequency and when the operating current reaches the threshold current.

5. The compressor as claimed in claim 1, wherein the control device includes at least one of (i) a sampling unit configured to signal an actual operating current of the electric motor with a predefinable sampling rate, and (ii) a comparison unit configured to compare the signaled actual operating current with the threshold current as a function of time.

6. The compressor as claimed in claim 1, wherein at least one of (i) a first time phase of a start phase after a starting request of the compressor unit is free of direct limitation of amplitude of the operating current and (ii) a second time phase of the start phase after the first time phase predefines in chronologically variable manner the threshold current that limits the operating current.

7. The compressor as claimed in claim 6, wherein the first time phase has a starting period that is predefinable in one of a variably fixed manner and as a function of a measured operating voltage, and has a duration less than a dwell time in a start section of the second time phase.

8. The compressor as claimed in claim 3, wherein at least one of (i) at least one maximum value and (ii) at least one gradient of at least one of the threshold current and the operating current is predefinable by the threshold current-limiting function.

9. The compressor as claimed in claim 6, wherein the threshold current-limiting function is predefined in the second time phase as a linear function of time.

10. The compressor as claimed in claim 1, wherein the electronic control module is configured to control a soft start, to permit an unlimited start operating current in a chronologically limited first time phase and to predefine the start operating current, which is limited in a chronologically variable manner, in a chronologically limited second time phase.

11. The compressor as claimed in claim 1, wherein the program module is configured to predefine a number of first start threshold current-limiting functions for a number of first start time periods in a start phase for a start operating current, and to predefine a number of second start threshold current-limiting functions for a number of second start time periods.

12. The compressor as claimed in claim 1, wherein the compressor unit is configured such that a changeover from a start phase having a soft start to a load phase having load-unlimited running is effected independently of an operating current of the compressor unit.

13. The compressor as claimed in claim 1, wherein the electronic control module is configured to control a soft shutdown to predefine a chronologically limited time phase of a shutdown operating current that is limited in a chronologically variable manner.

14. The compressor as claimed in claim 13, wherein the program module is configured to predefine, for the shutdown operating current, at least one number of first shutdown threshold current-limiting functions for a number of first shutdown time periods, and a number of second shutdown threshold current-limiting functions for a number of second shutdown time periods.

15. The compressor as claimed in claim 1, wherein the electronic control device includes a first regulating unit configured to regulate the operating current of the electric motor while predefining the threshold current as a setpoint current.

16. The compressor as claimed in claim 15, wherein the electronic control device includes a regulating module having a second regulating unit configured to regulate a rotational speed of the electric motor while predefining a rotational speed upper limit that is constant in at least one area as a function of one of the operating current and a variable derived from the operating current.

17. The compressor as claimed in claim 15, wherein the first regulating unit is configured to limit a rotational speed variability of the electric motor as a function of one of the operating current and a variable derived from the operating current over a PWM characteristic curve, in the form of an effective voltage ramp, stored in the program module, as a function of the operating current.

18. The compressor as claimed in claim 17, wherein the PWM characteristic curve defines a lower effective voltage corresponding to a low PWM value when a low current is present, and an upper effective voltage corresponding to a high PWM value when a high current is present, wherein the lower effective voltage is below the upper effective voltage, and the rotational speed variability of the electric motor has an upper rotational speed value when a low current is present and a lower rotational speed value when a high current is present, and wherein the upper rotational speed value is above the lower rotational speed value.

19. The compressor as claimed in claim 1, further comprising an analysis unit configured to (i) determine an actual rotational speed of the compressor unit from a chronological profile of the operating current, (ii) determine a frequency from a plurality of periodic peaks of a current ripple, and (iii) assign the frequency to an actual rotational speed of the compressor unit, the actual rotational speed being an input value for a first regulating unit of a regulating module of the electronic control device and to regulate a rotational speed of the electric motor.

24. The compressor as claimed in claim 3, wherein the another operating parameter of the motor is an operating voltage.

25. The compressor as claimed in claim 5, wherein the predefinable sampling rate is in a range of about 1 Hz to 10 000 Hz.

20. A compressed air supply system for operating a pneumatic system of a vehicle, the compressed air supply system comprising:

a compressed air feed having a compressor for producing compressed air, a brushed DC electric motor and a compressor unit;

a compressed air port to the pneumatic system;

a venting port to the surroundings;

a first pneumatic connection between the compressed air feed and the compressed air port, the pneumatic connection having an air dryer and an isolating valve; and

a second pneumatic connection between the compressed air port and the venting port.

21. A vehicle air spring system, comprising the compressed air supply system as claimed in claim 20, a gallery, at least one branch line connected pneumatically to the gallery, at least one of a bellows and an accumulator, and a directional control valve upstream of the at least one of a bellows and accumulator.

22. A method for operating a brushed DC electric motor in a compressor for producing compressed air for a compressed air supply system of a vehicle, the motor being (i) configured to drive a compressor unit, and (ii) controllable by an electronic control module having a control assembly and an executable program module, the method comprising predefining by the control module a threshold current that limits an operating current of the motor in a chronologically variable manner.

23. The method as claimed in claim 22, further comprising predefining at least one threshold current-limiting function of the threshold current as a function of time, and interrupting operation of the motor by the control module by interrupting an operating voltage of the motor when the operating current reaches the threshold current of the at least one threshold current-limiting function.