Method and system for generating compressed air for at least one vehicle, in particular for at least one rail vehicle

Abstract

A method and system for generating compressed air for at least one vehicle, in particular at least one rail vehicle, is disclosed. The method includes the step a) of selectively connecting a first compressor (303), or a second compressor (307), or simultaneously the first compressor (303) and the second compressor (307), to an electric motor (301) configured to generate a drive torque. Also disclosed is a system for generating compressed air for at least one vehicle.

Description

[Technical field]

[0001] The present invention relates generally to the field of braking systems, particularly railway braking systems. In particular, the present invention relates to a method for generating compressed air for at least one vehicle or a convoy of vehicles and to a system for generating compressed air for at least one vehicle or a convoy of vehicles. [Background technology]

[0002] The prior art is described below with particular reference to the field of rail vehicles, nevertheless what is described below may also be applied, where possible, to other fields of vehicles.

[0003] Braking and suspension systems for rail vehicles for passenger transport are powered by compressed air.

[0004] A prior art system for generating compressed air is shown in FIG.

[0005] Such a system for generating compressed air 100 comprises a motor 101 , the motor shaft 102 of which provides a driving torque to a motor shaft 103 of a compressor 104 via an elastic coupling 105 .

[0006] Via an inlet 106, the compressor 104 draws in air at atmospheric pressure, compresses it and supplies it via a pneumatic connection 107 and a check valve 108 to a dryer unit 109. The dryer unit 109 has the purpose of removing the liquid components and water vapor resulting from the compression of the moist air and of supplying the dry air to a main reservoir 110 via a second duct 111 and a second check valve 112.

[0007] The control unit 113 receives power 115 and measures the pressure in the main reservoir 110 via a pressure transducer 114 .

[0008] When the pressure in the main reservoir 110 is equal to or lower than the minimum value Pmin, the control unit 113 supplies power to the electric motor 101 .

[0009] The control unit 113 cuts off the power supply to the electric motor 101 when the pressure in the main reservoir 110 reaches or exceeds a maximum value Pmax.

[0010] In the railway sector, the minimum value Pmin typically ranges from 6 bar to 7 bar, and the maximum value Pmax typically ranges from 9 bar to 10 bar.

[0011] It is prior art that a system 100 for generating compressed air is integrated inside an acoustically isolated metal structure with a damping connection to the rail vehicle in order to reduce the noise and vibrations transmitted respectively to the body of the rail vehicle.

[0012] Through a distribution duct 116, the compressed air stored in the main reservoir 110 is supplied to at least one user system 117, 118, such as, for example, a braking system, a suspension system, a toilet, a pantograph, a door, etc.

[0013] FIG. 2 illustrates a typical rail car platoon 200 for transporting passengers.

[0014] Two compressed air generating systems 201 and 202 , which correspond to the compressed air generating system 100 of FIG. 1, supply compressed air to a main duct 203 which in turn supplies compressed air via a check valve 215 to a main reservoir 204 .

[0015] From the main reservoir 204, various systems 205, 206, 207, such as, for example, the braking system, the suspension, the toilet, etc., draw compressed air for their operation.

[0016] The two compressed air generating systems 201, 202 are considered necessary for redundancy reasons, i.e. to ensure a permanent supply of compressed air even in case one of the two compressed air generating systems 201, 202 fails during daily operating service.

[0017] The control system 208 alternatively enables two compressed air generating systems 201, 202 by means of supply signals 209, 210. This means, although it is inconvenient, that on average one of the two compressed air generating systems 201, 202 is unused during operational service.

[0018] The weight of each compressed air generating system 201, 202 often exceeds 500 kg, requiring the expenditure of unnecessary energy to accelerate its mass, which is then ultimately lost during braking due to insufficient efficiency of the regenerative braking system or due to mechanical friction braking which is essentially dissipative.

[0019] Generally, a single compressed air generating system can provide the full capacity of compressed air for the combined cost of two systems. Summary of the Invention [Problem to be solved by the invention]

[0020] The object of the present invention is to provide a method and a system for generating compressed air for at least one vehicle, in particular at least one railway vehicle, which reduces weight and costs compared to prior art compressed air generation systems while respecting redundancy requirements. [Means for solving the problem]

[0021] These and other objects and advantages are achieved according to aspects of the present invention by a method for generating compressed air for at least one vehicle having the features defined in claim 1 and by a system for generating compressed air for at least one vehicle having the features defined in claim 6. Preferred embodiments of the invention are defined in the dependent claims, the content of which is to be understood as an integral part of this description. [Brief description of the drawings]

[0022] The functional and structural features of some preferred embodiments of the system for generating compressed air for at least one vehicle according to the invention will now be described with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 shows an exemplary system for generating compressed air for at least one vehicle, in particular at least one rail vehicle, according to the prior art. [Diagram 2] FIG. 2 illustrates an exemplary rail vehicle platoon for transporting passengers. [Diagram 3] FIG. 3 shows a first embodiment of a compressed air generating system for at least one vehicle. [Figure 4] FIG. 4 shows a further embodiment of the compressed air generating system for at least one vehicle. [Diagram 5] FIG. 5 illustrates yet another embodiment of a compressed air generating system for at least one vehicle. [Figure 6] FIG. 6 illustrates a graph of an exemplary operating cycle of a compressed air generating system of at least one vehicle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Before describing the embodiments of the present invention in detail, it should be made clear that the present invention is not limited in its application to the design details and configuration of components set forth in the following description or illustrated in the drawings. The present invention can envision other embodiments and can actually be implemented or constructed in different ways. It is also to be understood that the phraseology and terminology are for descriptive purposes and should not be construed as limiting. The use of "include" and "comprise" and variations thereof should be understood to encompass the elements described below and their equivalents, as well as additional elements and their equivalents.

[0024] In a first embodiment, a method for generating compressed air for at least one vehicle, in particular a rail vehicle, comprises the following step a): a) Selectively connecting or disconnecting the first compressor 303, or the second compressor 307, or simultaneously the first compressor 303 and the second compressor 307, to an electric motor 301 configured to generate a driving torque.

[0025] Preferably, the method further comprises a step of measuring a pressure value indicative of the internal pressure of a main reservoir 311 arranged to accumulate the compressed air generated by the first compressor 303 and the second compressor 307.

[0026] The pressure value in the main reservoir 311 can over time fall within a range of pressures, including a null value, a first predefined pressure value Pmin (greater than the null value), and a second predefined pressure value Pmax greater than the first predefined pressure value Pmin.

[0027] Preferably, when the pressure value in the main reservoir 311 is lower than a first predetermined pressure value Pmin, step a) comprises the following steps (1)-(3): (1) connecting the first compressor 303 to the electric motor 301; (2) connecting the second compressor 307 to the electric motor 301; (3) maintaining the first compressor (303) and the second compressor (307) connected to the electric motor (301) until the pressure value in the main reservoir (311) reaches or exceeds the first predetermined pressure value (Pmin) (i.e., until the pressure value in the main reservoir 311 is equal to or higher than the first predetermined pressure value Pmin).

[0028] Preferably, in addition to or instead of the condition mentioned above where the pressure value is lower than a first predetermined pressure value Pmin, if the pressure value in the main reservoir 311 is equal to or higher than a second predetermined pressure value Pmax, step a) comprises the following steps (1)-(3): (1) decoupling or maintaining the first compressor 303 decoupled from the electric motor 301; (2) decoupling or maintaining the second compressor 307 decoupled from the electric motor 301; (3) A step of maintaining a state in which the first compressor 303 and the second compressor 307 are separated from the electric motor 301 until the pressure value in the main reservoir 311 becomes equal to or lower than the first predetermined pressure value Pmin.

[0029] Preferably, in addition to or instead of the mentioned condition of said pressure value being lower than a first predefined pressure value Pmin and the condition of said pressure value being equal to or greater than a second predefined pressure value Pmax, when the pressure value in said main reservoir 311 is equal to the first predefined pressure value Pmin or is comprised between the first predefined pressure value Pmin and the second predefined pressure value Pmax, step a) may selectively carry out the following steps (1)-(3) or (1′)-(3′): (1) connecting or keeping the second compressor (307) connected to the electric motor (301); (2) decoupling or keeping the first compressor (303) decoupled from the electric motor (301); (3) keeping the second compressor (307) connected to the electric motor (301) and keeping the first compressor (303) disconnected from the electric motor (301) until a pressure value in the main reservoir (311) becomes equal to or greater than a second predetermined pressure value (Pmax); or (1') decoupling or keeping the second compressor (307) decoupled from the electric motor (301); (2') connecting or keeping the first compressor (303) connected to the electric motor (301); (3') keeping the second compressor (307) disconnected from the electric motor (301) and keeping the first compressor (303) connected to the electric motor (301) until the pressure value in the main reservoir (311) becomes equal to or greater than a second predetermined pressure value (Pmax).

[0030] In another aspect of the invention, with reference to FIG. 3, a first embodiment of a system for generating compressed air for at least one vehicle, in particular at least one rail vehicle, is shown.

[0031] Such a system for generating compressed air for at least one vehicle comprises an electric motor 301 configured to generate a drive torque.

[0032] The system for generating compressed air for at least one vehicle further comprises a first coupling means 304 arranged to selectively assume a first state connecting the electric motor 301 to the first compressor 303 or a second state disconnecting the electric motor 301 from the first compressor 303, and a second coupling means 308 arranged to selectively assume a first state connecting the electric motor 301 to the second compressor 307 or a second state disconnecting the electric motor 301 from the second compressor 307.

[0033] The at least one vehicle compressed air generating system further comprises a control means 320 configured to control the transition of the first coupling means 304 between the first state and the second state (and vice versa), which also controls the transition of the second coupling means 308 between the first state and the second state (and vice versa), such that a driving torque generated by the electric motor 301 is selectively provided to the first compressor 303 or the second compressor 307, or to the first compressor 303 and the second compressor 307 simultaneously.

[0034] The control means may include, for example, at least one of a control unit, a processor, a microprocessor, a controller, a microcontroller, an FPGA, a PLC, and the like.

[0035] Preferably, the compressed air generating system of at least one vehicle may comprise a main reservoir 311 configured to store the compressed air generated by the first compressor 303 and the second compressor 307, and a pressure sensor means configured to measure the pressure in the main reservoir 311.

[0036] The pressure value in the main reservoir 311 can be within a range of pressures, including a null value, a first predefined pressure value Pmin (greater than said null value), and a second predefined pressure value Pmax greater than said first predefined pressure value Pmin.

[0037] The pressure sensor means may for example be or comprise a pressure sensor or a pressure measuring device.

[0038] Preferably, when the pressure value measured by the pressure sensor means is lower than a first predetermined pressure value Pmin, the control means 320 performs the following control. - controlling the first coupling means 304 to be in a first state connecting the electric motor 301 to the first compressor 303; - controlling the second coupling means 308 to be in a first state connecting the electric motor 301 to the second compressor 307; - maintaining the first coupling means 304 in the first state and maintaining the second coupling means 308 in the first state until the pressure value measured by the pressure sensor means reaches or exceeds the first predetermined pressure value Pmin (i.e. until the pressure value in the main reservoir 311 is equal to or higher than the first predetermined pressure value Pmin).

[0039] By higher than the first predetermined pressure value Pmin, one can understand, for example, a value equal to a second predetermined pressure value Pmax higher than the first predetermined pressure value Pmin, or a value between the first predetermined pressure value Pmin and the second predetermined pressure value Pmax.

[0040] For example, the control means 320: - causing the first coupling means 304 to assume a first state in which the electric motor 301 is connected to the first compressor 303, and transmitting a driving torque generated by the electric motor 301 to the first compressor 303; The second coupling means 308 is caused to assume a first state in which the electric motor 301 is connected to the second compressor 307, and the driving torque generated by the electric motor 301 is transmitted to the second compressor 307.

[0041] Preferably, if the pressure value measured by the pressure sensor means is lower than a first predetermined pressure value Pmin, the control means 320: The electric motor 301 is driven to generate a driving torque having a first torque value.

[0042] In other words, referring to the exemplary operating cycle of FIG. 6, at a moment T0 of ignition of a vehicle or platoon, such as a rail car or rail car platoon, the control means 320 (e.g., control unit) may control the first coupling means 304 (e.g., first electromechanical clutch) and the second coupling means 308 (e.g., second electromechanical clutch 308) in a first state in which they transmit the driving torque of the electric motor 301 to the first compressor 303 and the second compressor 307, and may control the electric motor 301 to rotate at a first speed V1 to generate a driving torque having a first torque value and to bring the pressure in the main reservoir 311 to a first predetermined pressure value Pmin as quickly as possible.

[0043] In addition to or instead of what has been mentioned for the condition where the pressure value is lower than the first predefined pressure value Pmin, preferably, when the pressure value measured by the pressure sensor means is equal to the first predefined pressure value Pmin or is included between the first predefined pressure value Pmin and a second predefined pressure value Pmax, the control means 320 may perform the following control as (1)-(2) or (1')-(2'): (1) controlling the second coupling means 308 to be in a first state to connect the electric motor 301 to the second compressor 307, and controlling the first coupling means 304 to be in a second state to disconnect the electric motor 301 from the first compressor 303; (2) controlling the second coupling means 308 to be maintained in its first state and the first coupling means 304 to be maintained in its second state until the pressure value measured by the pressure sensor means becomes equal to or greater than a second predetermined pressure value Pmax, which is greater than the first predetermined pressure value Pmin; or (1') controlling the first coupling means 304 to be in a first state to connect the electric motor 301 to the first compressor 303, and controlling the second coupling means 308 to be in a second state to disconnect the electric motor 301 from the second compressor 307; (2') The first coupling means 304 is maintained in its first state, and the second coupling means 308 is controlled to be maintained in its second state, until the pressure value measured by the pressure sensor means becomes equal to or greater than a second predetermined pressure value Pmax that is greater than the first predetermined pressure value Pmin.

[0044] For example, the control means 320 may selectively perform the following controls (1)-(2) or (1′)-(2′): (1) if the second coupling means 308 is already in its first state, maintain the second coupling means 308 in its first state, and cause the first coupling means 304 to assume or maintain a second state in which the electric motor 301 is decoupled from the first compressor 303, so that the driving torque generated by the electric motor 301 is not transmitted to the first compressor 303; (2) if the second coupling means 308 is not yet in its first state, control the second coupling means 308 to assume a first state in which the electric motor 301 is connected to the second compressor 307 so that the driving torque generated by the electric motor 301 is transmitted to the second compressor 307, and control the first coupling means 304 to assume or maintain a second state in which the electric motor 301 is disconnected from the first compressor 303 so that the driving torque generated by the electric motor 301 is not transmitted to the first compressor 303; or (1') if the first coupling means 304 is already in its first state, maintain the first coupling means 304 in its first state, and cause the second coupling means 308 to assume or maintain a second state in which the electric motor 301 is decoupled from the second compressor 307, so that the driving torque generated by the electric motor 301 is not transmitted to the second compressor 307; (2') If the first connecting means 304 is not yet in its first state, control the first connecting means 304 to assume a first state in which the electric motor 301 is connected to the first compressor 303 so that the driving torque generated by the electric motor 301 is transmitted to the first compressor 303, and control the second connecting means 308 to assume or maintain a second state in which the electric motor 301 is disconnected from the second compressor 307 so that the driving torque generated by the electric motor 301 is not transmitted to the second compressor 303.

[0045] For example, referring to the exemplary operating cycle of FIG. 6, following the moment T2 when the second predetermined pressure value Pmax is reached, the pressure in the main reservoir 311 begins to decrease towards the first predetermined pressure value Pmin due to a demand for compressed air by one or more users 205, 206, 207. At a moment T3, when the pressure in the main reservoir 311 reaches a first predetermined pressure value Pmin (i.e., when the pressure in the main reservoir needs to be changed from the first predetermined pressure value Pmin to a second predetermined pressure value Pmax), the control unit 320 can select which of the first compressor 303 and the second compressor 307 should be coupled to the electric motor 301, and can connect the selected compressor to the electric motor 301 by controlling a coupling means (e.g., an electromechanical clutch) associated with the selected compressor, and can control the electric motor 301 to transmit a driving torque from the electric motor 301 to the selected compressor in a first state, for example, to rotate at a second speed V2 less than or equal to the first speed V1, i.e., V2≦V1. The other non-selected compressor is not connected to the electric motor 301 in a second state in which no driving torque is transmitted from the electric motor 301 to the non-selected compressor, by controlling a coupling means (e.g., an electromechanical clutch) associated with the non-selected compressor. In the above-described embodiment, the preselected compressor may be any one of the compressors between the first compressor 303 and the second compressor 307 .

[0046] Preferably, according to a first criterion, the control means 320 may be configured to measure a first total operating time of the first compressor 303 and to measure a second total operating time of the second compressor 307.

[0047] When the pressure value measured by the pressure sensor means is equal to a first predetermined pressure value Pmin or is comprised between a first predetermined pressure value Pmin and a second predetermined pressure value Pmax, and the first total activation time of the first compressor 303 is greater (longer) than the second total activation time of the second compressor 307, the control means 20: - controlling the second coupling means 308 to be in a first state connecting the electric motor 301 to the second compressor 307 and controlling the first coupling means 304 to be in a second state disconnecting the electric motor 301 from the first compressor 303; maintaining said second coupling means 308 in its first state and maintaining said first coupling means 304 in its second state until the pressure value measured by said pressure sensor means is greater than or equal to said second predetermined pressure value Pmax, which is greater than said first predetermined pressure value Pmin.

[0048] For example, the control means 320 may: - if the second coupling means 308 is already in its first state, maintaining the second coupling means 308 in its first state and causing the first coupling means 304 to assume or maintain a second state decoupling the electric motor 301 from the first compressor 303, such that the drive torque generated by the electric motor 301 is not transmitted to the first compressor 303; - if the second coupling means 308 is not already in its first state, causing the second coupling means 308 to assume a first state in which it couples the electric motor 301 to the second compressor 307, such that the driving torque generated by the electric motor 301 is transmitted to the second compressor 307, and causing the first coupling means 304 to assume or maintain a second state in which it decouples the electric motor 301 from the first compressor 303, such that the driving torque generated by the electric motor 301 is not transmitted to the first compressor 303.

[0049] Alternatively, if the pressure value measured by the pressure sensor means is equal to a first predetermined pressure value Pmin or is comprised between a first predetermined pressure value Pmin and a second predetermined pressure value Pmax, and the first total activation time of the first compressor 303 is shorter than the second total activation time of the second compressor 307, the control means 320: - controlling the first coupling means 304 to be in a first state connecting the electric motor 301 to the first compressor 303 and controlling the second coupling means 308 to be in a second state disconnecting the electric motor 301 from the second compressor 307; maintaining said first coupling means 304 in its first state and said second coupling means 308 in its second state until the pressure value measured by said pressure sensor means is greater than or equal to a second predetermined pressure value Pmax, which is greater than said first predetermined pressure value Pmin.

[0050] For example, the control means 320 may: - if said first coupling means 304 is already in its first state, maintaining said first coupling means 304 in its first state and causing said second coupling means 308 to assume or maintain a second state which decouples said electric motor 301 from said second compressor 307, such that the driving torque generated by said electric motor 301 is not transmitted to said second compressor 307; - if the first connecting means 304 is not yet in a first state, cause the first connecting means 304 to assume a first state in which the electric motor 301 is connected to the first compressor 303, so that the driving torque generated by the electric motor 301 is transmitted to the first compressor 303, and cause the second connecting means 308 to assume or maintain a second state in which the electric motor 301 is disconnected from the second compressor 307, so that the driving torque generated by the electric motor 301 is not transmitted to the second compressor 307.

[0051] In other words, in the first criterion described above, when the pressure in the main reservoir needs to be increased from the first predetermined pressure value Pmin to the second predetermined pressure value Pmax, the control means 320 (e.g., the control unit) may count the cumulative usage time of the first compressor and the second compressor, and select the compressor with the shortest usage time to connect to the electric motor, so that the consumption of the components of the first compressor and the second compressor is more even and the maintenance interval deadlines are reached at the same time.

[0052] Preferably, according to a second criterion, the control means 320 may be arranged to measure a first total operating time of said first compressor 303 and to measure a second total operating time of said second compressor 307. In that case, said control means 320 may: - preventing operation of the first compressor 303 during a first inhibition period if the first total operating time of the first compressor 303 is longer than the second total operating time of the second compressor 307; - if the first total operating time of the first compressor 303 is shorter than the second total operating time of the second compressor 307, preventing operation of the second compressor 307 during a second inhibition period.

[0053] In this case, if, during the first suppression period, the pressure value measured by the pressure sensor means is equal to the first predetermined pressure value Pmin or is between the first predetermined pressure value Pmin and a second predetermined pressure value Pmax, the control means 320: - controlling the second coupling means 308 to be in a first state connecting the electric motor 301 to the second compressor 307 and controlling the first coupling means 304 to be in a second state disconnecting the electric motor 301 from the first compressor 303; maintaining said second coupling means 308 in its first state and said first coupling means 304 in its second state until the pressure value measured by said pressure sensor means is greater than or equal to said second predetermined pressure value Pmax, which is greater than said first predetermined pressure value Pmin.

[0054] For example, the control means 320: - if said second coupling means 308 is already in its first state, maintaining said second coupling means 308 in its first state and causing said first coupling means 304 to assume or maintain a second state decoupling said electric motor 301 from said first compressor 303, such that the drive torque generated by said electric motor 301 is not transmitted to said first compressor 303; - if the second coupling means 308 is not yet in its first state, causing the second coupling means 308 to assume a first state in which it couples the electric motor 301 to the second compressor 307, so that the driving torque generated by the electric motor 301 is transmitted to the second compressor 307, and causing the first coupling means 304 to assume or maintain a second state in which it disconnects the electric motor 301 from the first compressor 303, so that the driving torque generated by the electric motor 301 is not transmitted to the first compressor 303.

[0055] If, during the second inhibition period, the pressure value measured by the pressure sensor means is equal to the first predetermined pressure value Pmin or is comprised between the first predetermined pressure value Pmin and the second predetermined pressure value Pmax, the control means 320: - controlling the first coupling means 304 to be in a first state connecting the electric motor 301 to the first compressor 303 and controlling the second coupling means 308 to be in a second state disconnecting the electric motor 301 from the second compressor 307; maintaining said first coupling means 304 in its first state and said second coupling means 308 in its second state until the pressure value measured by said pressure sensor means is greater than or equal to said second predetermined pressure value Pmax, which is greater than said first predetermined pressure value Pmin.

[0056] For example, the control means 320 may: - if the first coupling means 304 is already in its first state, maintaining the first coupling means 304 in its first state and causing the second coupling means 308 to assume or maintain a second state that decouples the electric motor 301 from the second compressor 307 so that the driving torque generated by the electric motor 301 is not transmitted to the second compressor 307; - if the first connecting means 304 is not yet in a first state, cause the first connecting means 304 to assume a first state in which the electric motor 301 is connected to the first compressor 303, so that the driving torque generated by the electric motor 301 is transmitted to the first compressor 303, and cause the second connecting means 308 to assume or maintain a second state in which the electric motor 301 is disconnected from the second compressor 307, so that the driving torque generated by the electric motor 301 is not transmitted to the second compressor 307.

[0057] In other words, in the second criterion described above, the control unit 320 may recount the accumulated usage time of the first compressor and the second compressor, and for example, at the start of an operating day, the control unit 320 may select the compressor with the shortest accumulated usage time, and when it is necessary to bring the pressure in the main reservoir from the first predetermined pressure value Pmin to the second predetermined pressure value Pmax, the control unit 320 may use the selected compressor for only a predetermined period of time and prohibit use of other compressors during such predetermined period (e.g., all day).

[0058] Preferably, according to a third criterion, the control unit may be configured to define a first time interval during which operation of the first compressor 303 is prevented and a second time interval during which operation of the second compressor 307 is prevented. The first time interval and the second time interval may alternate with each other over time. If, in one of the first time intervals, the pressure value measured by the pressure sensor means is equal to the first predefined pressure value Pmin or is comprised between the first predefined pressure value Pmin and the second predefined pressure value Pmax, the control means 320: - controlling the second coupling means 308 to be in a first state connecting the electric motor 301 to the second compressor 307 and controlling the first coupling means 304 to be in a second state disconnecting the electric motor 301 from the first compressor 303; maintaining said second coupling means 308 in its first state and said first coupling means 304 in its second state until the pressure value measured by said pressure sensor means is greater than or equal to said second predetermined pressure value Pmax, which is greater than said first predetermined pressure value Pmin.

[0059] For example, the control means 320 may: - if the second coupling means 308 is already in its first state, maintaining the second coupling means 308 in its first state and causing the first coupling means 304 to assume or maintain a second state decoupling the electric motor 301 from the first compressor 303, such that the drive torque generated by the electric motor 301 is not transmitted to the first compressor 303; - if the second connecting means 308 is not yet in a first state, cause the second connecting means 308 to assume a first state in which the electric motor 301 is connected to the second compressor 307, so that the driving torque generated by the electric motor 301 is transmitted to the second compressor 307, and cause the first connecting means 304 to assume a second state in which the electric motor 301 is disconnected from the first compressor 303, so that the driving torque generated by the electric motor 301 is not transmitted to the first compressor 303.

[0060] Furthermore, if, during one of said second time intervals, the pressure value measured by said pressure sensor means is equal to said first predetermined pressure value Pmin or is comprised between said first predetermined pressure value Pmin and said second predetermined pressure value Pmax, said control means 320: - controlling the first coupling means 304 to be in a first state connecting the electric motor 301 to the first compressor 303 and controlling the second coupling means 308 to be in a second state disconnecting the electric motor 301 from the second compressor 307; maintaining said first coupling means 304 in its first state and said second coupling means 308 in its second state until the pressure value measured by said pressure sensor means is greater than or equal to said second predetermined pressure value Pmax, which is greater than said first predetermined pressure value Pmin.

[0061] For example, the control means 320 may: - if the first coupling means 304 is already in its first state, maintaining the first coupling means 304 in its first state and causing the second coupling means 308 to assume or maintain a second state that decouples the electric motor 301 from the second compressor 307, such that the driving torque generated by the electric motor 301 is not transmitted to the second compressor 307; - if the first connecting means 304 is not yet in a first state, cause the first connecting means 304 to assume a first state in which the electric motor 301 is connected to the first compressor 303, so that the driving torque generated by the electric motor 301 is transmitted to the first compressor 303, and cause the second connecting means 308 to assume or maintain a second state in which the electric motor 301 is disconnected from the second compressor 307, so that the driving torque generated by the electric motor 301 is not transmitted to the second compressor 307.

[0062] In other words, if the third criterion described above requires the pressure in the main reservoir to be increased from the first predetermined pressure value Pmin to the second predetermined pressure value Pmax, the control unit 320 may alternatively use the two compressors alternately at regular intervals, for example, every other day. In this way, the selected compressor is maintained at room temperature for a period of time to limit the formation of condensation inside the compressor due to excessive cooling, and the wear of the first and second compressors is balanced.

[0063] Preferably, and applicable to all the above-mentioned embodiments, when the pressure value measured by the pressure sensor means is between the first predetermined pressure value Pmin and the second predetermined pressure value Pmax which is greater than the first predetermined pressure value Pmin, the control means 320: driving said electric motor 301 to generate a driving torque having a second torque value which is smaller than the first torque value;

[0064] Preferably, in addition or alternatively to what has been described above for the condition where the pressure value is lower than the first predetermined pressure value Pmin and for the condition where the pressure value is equal to the first predetermined pressure value Pmin or is comprised between the first predetermined pressure value Pmin and a second predetermined pressure value Pmax, if the pressure value measured by the pressure sensor means is equal to or greater than the second predetermined pressure value Pmax which is greater than the first predetermined pressure value Pmin, the control means 320: - controlling the first coupling means 304 to be in a second state decoupling the electric motor 301 from the first compressor 303; - controlling the second coupling means 308 to be in a second state decoupling the electric motor 301 from the second compressor 307; maintaining said first coupling means 304 in its second state and maintaining said second coupling means 308 in its second state until the pressure value measured by said pressure sensor means is less than or equal to said first predetermined pressure value Pmin.

[0065] For example, the control means 320 may: - if the first coupling means 304 is not already in its second state, causing the first coupling means 304 to assume a second state that decouples the electric motor 301 from the first compressor 303 so that the driving torque generated by the electric motor 301 is not transmitted to the first compressor 303; - if the second coupling means 308 is not already in the second state, causing the second coupling means 308 to assume a second state that disconnects the electric motor 301 from the second compressor 307, so that the driving torque generated by the electric motor 301 is not transmitted to the second compressor 307.

[0066] In other words, with respect to the exemplary operating cycle of FIG. 6 , at the instant T2, when the pressure value Pmax is reached, the control means 320 can stop the electric motor 301 and control the first coupling means 304 (e.g., the first electromechanical clutch) and the second coupling means 308 (e.g., the second electromechanical clutch 308) in a second state in which no driving torque is transmitted from the electric motor 301 to the first compressor 303 and the second compressor 307, respectively.

[0067] Preferably, if the pressure value measured by said pressure sensor means is greater than or equal to a second predetermined pressure value Pmax, said control means 320: The electric motor 301 may be driven to generate a driving torque of zero value.

[0068] Preferably, the at least one vehicle compressed air generating system may comprise a first air dryer means 310 and a second air dryer means 313. The first air dryer means 310 may be configured to receive compressed air generated by the first compressor 303 and generate a first dry compressed air that is supplied to the main reservoir 311. The second air dryer means 313 may be configured to receive compressed air generated by the second compressor 307 and generate a second dry compressed air that is supplied to the main reservoir 311.

[0069] For example, the first compressor 303 may feed a first dryer 310, which may feed a main reservoir 311 via a check valve 312. The second compressor 307 may feed a second dryer 313, which feeds the main reservoir 311 via a check valve 314.

[0070] Alternatively, at least one vehicle's compressed air generating system may comprise only one air dryer means, which may be configured to receive compressed air generated by the first compressor 303 and compressed air generated by the second compressor 307 and generate dried compressed air which is supplied to said main reservoir 311.

[0071] For example, with reference to FIG. 4, a first compressor 303 and a second compressor 307 may supply compressed air to a single dryer 310, for example, via two check valves 312, 314, respectively.

[0072] Preferably, the electric motor 301 may comprise a first drive shaft 302 arranged to transmit a driving torque to a first compressor 303 via a first connecting means 304 and a first mechanical connecting part 305, and a second drive shaft 306 integrated with the first drive shaft 302 and arranged to transmit a driving torque to a second compressor 307 via a second connecting means 308 and a second mechanical connecting part 309.

[0073] Preferably, in a further embodiment, the electric motor 301 may comprise a drive shaft 501 to which the first coupling means 304 and the second coupling means 308 are arranged to be coupled. In this case, the compressed air generating system of the at least one vehicle may comprise a first pulley 505 and a second pulley 507. The first pulley 505 is arranged to be mechanically coupled to the shaft 504 of the first compressor 303, and the second pulley 507 is arranged to be mechanically coupled to the shaft 506 of the second compressor 307. The first coupling means 502, 304 may be configured to transmit a drive torque to the first pulley 505 by at least one drive belt 508, and the second coupling means 503, 308 may be configured to transmit a drive torque to the second pulley 507 by at least one drive belt 509.

[0074] Preferably, the first coupling means 304 may be an electromechanical clutch.

[0075] Preferably, the second coupling means 308 may be an electromechanical clutch.

[0076] For example, the first predetermined pressure value Pmin may typically take a value between 6 bar and 7 bar, and the second predetermined pressure value Pmax may typically take a value between 9 bar and 10 bar.

[0077] In a first embodiment, the compressed air generating system 300 may comprise an electric motor 301 having a first drive shaft 302 for transmitting a driving torque to a first compressor 303 via a first coupling means 304, such as a first electromechanical clutch, and a first mechanical coupling 305.

[0078] Furthermore, the electric motor 301 may comprise a second drive shaft 306 integral with the first drive shaft 302 for transmitting a drive torque to the second compressor 307 via a second coupling means 308, such as a second electromechanical clutch, and a second mechanical coupling 309.

[0079] The first compressor 303 may feed a first dryer means 310 , for example a first dryer, which may feed a main reservoir 311 through a check valve 312 .

[0080] The second compressor 307 may feed a second dryer means 313 , for example a second dryer, which may feed the main reservoir 311 through a check valve 314 .

[0081] The control means 320, e.g. a control unit, comprises: - receive power supply 321; The first coupling means 304 is controlled via a power signal 323 between a first state in which the first coupling means 304 transmits a drive torque from the electric motor 301 to the first compressor 303 and a second state in which the first coupling means 304 does not transmit a torque from the electric motor 301 to the first compressor 303. - the second coupling means 308 is actuated via the power signal 324 in a first state in which the second coupling means 308 transmits a driving torque from the electric motor 301 to the second compressor 307 and in a second state in which the second coupling means 308 does not transmit a driving torque from the electric motor 301 to the second compressor 307; - The electric motor 301 is driven at variable speed by means of a group of power signals 325.

[0082] A pressure sensor means 321 , for example a pressure transducer 321 , is capable of measuring the pressure in the main reservoir 311 and transmitting said value 322 to the control unit 320 .

[0083] In a second embodiment, with reference to Fig. 5, the electric motor 301 may have a drive shaft 501 to which a first coupling means 502, e.g. a first electromechanical clutch, and a second coupling means 503, e.g. a second electromechanical clutch, are mechanically coupled. Both coupling means 502, 503 may have the periphery of a pulley for driving at least one drive belt. The first pulley 505 is mechanically coupled to a shaft 504 of the first compressor 303 and the second pulley 507 is mechanically coupled to a shaft 506 of the second compressor 307.

[0084] The first coupling means 502 is capable of transmitting a drive force to a first pulley 505 by means of at least one drive belt 508. The second coupling means 503 is capable of transmitting a drive force to a second pulley 507 by means of at least one drive belt 509.

[0085] The control means 320, for example the control unit 320, is configured to: - receive power supply 321; - controlling the first coupling means 503 through the power signal 323 between a first state in which the first coupling means 503 transmits a driving torque from the electric motor 301 to the first compressor 303 and a second state in which the first coupling means 503 does not transmit a torque from the electric motor 301 to the first compressor 303; The second coupling means 503 is driven via the power signal 324 in a first state in which the second coupling means 503 transmits a driving torque from the electric motor 301 to the second compressor 307, and in a second state in which the second coupling means 308 does not transmit a driving torque from the electric motor 301 to the second compressor 307. - The electric motor 301 is driven at variable speed by means of a group of power signals 325.

[0086] What has been described above with respect to at least one vehicle, e.g., a rail car, may be equally applied to a plurality of rail cars connected together, e.g., to form a rail car platoon.

[0087] As can be seen, the present invention is particularly applicable in the field of rail vehicles / platoons traveling on rail tracks. For example, the vehicles referred to herein may be locomotives or freight cars, and the route / section may include rails with locomotive roll wheels thereon. The embodiments described herein are not limited to vehicles on tracks. For example, the vehicles may be automobiles, trucks (e.g., highway semi-trailer trucks, mining trucks, trucks for hauling timber, etc.), and the route may be a road or a track. For example, a platoon may comprise multiple such vehicles connected or associated with each other.

[0088] Various aspects and embodiments of the method for generating compressed air for at least one rail vehicle and the system for generating compressed air for at least one rail vehicle according to the invention have been described. It is to be understood that each embodiment can be combined with any other embodiment. Furthermore, the invention is not limited to the described embodiments but may be modified within the scope defined by the appended claims.

Claims

1. A method for generating compressed air for at least one vehicle, comprising: a) selectively connecting a first compressor (303) or a second compressor (307), or simultaneously the first compressor (303) and the second compressor (307), to an electric motor (301) configured to generate a driving torque; The method according to claim 1, further comprising:

2. A process of measuring a pressure value indicative of an internal pressure of a main reservoir (311) configured to store compressed air generated by the first compressor (303) and the second compressor (307); Including, The pressure value in the main reservoir (311) is A null value, a first predetermined pressure value (Pmin); a second predetermined pressure value (Pmax) greater than the first predetermined pressure value (Pmin); over time, taking values ​​in a pressure range including The method of claim 1 , wherein the method is configured to:

3. When the pressure value in the main reservoir (311) is less than the first predetermined pressure value (Pmin), the step a) connecting the first compressor (303) to the electric motor (301); connecting the second compressor (307) to the electric motor (301); maintaining the first compressor (303) and the second compressor (307) connected to the electric motor (301) until the pressure value in the main reservoir (311) reaches or exceeds the first predetermined pressure value (Pmin); The method of claim 2 , comprising:

4. When the pressure value in the main reservoir (311) is equal to or greater than the second predetermined pressure value (Pmax), the step a) decoupling or maintaining the first compressor (303) decoupled from the electric motor (301); decoupling or maintaining the second compressor (307) decoupled from the electric motor (301); maintaining the first compressor (303) and the second compressor (307) in a state in which they are disconnected from the electric motor (301) until the pressure value in the main reservoir (311) becomes equal to or lower than the first predetermined pressure value (Pmin); The method of claim 2 or claim 3, comprising:

5. When the pressure value in the main reservoir (311) is equal to the first predetermined pressure value (Pmin) or is between the first predetermined pressure value (Pmin) and the second predetermined pressure value (Pmax), The step a) connecting or maintaining the second compressor (307) connected to the electric motor (301); decoupling or maintaining the first compressor (303) decoupled from the electric motor (301); maintaining the second compressor (307) connected to the electric motor (301) and maintaining the first compressor (303) disconnected from the electric motor (301) until the pressure value in the main reservoir (311) becomes equal to or greater than the second predetermined pressure value (Pmax); Contains or Or, decoupling or maintaining the second compressor (307) decoupled from the electric motor (301); connecting or maintaining the first compressor (303) connected to the electric motor (301); maintaining the second compressor (307) in a state where it is disconnected from the electric motor (301) and maintaining the first compressor (303) in a state where it is connected to the electric motor (301) until the pressure value in the main reservoir (311) becomes equal to or greater than a second predetermined pressure value (Pmax); The method of claim 2 or claim 3, comprising:

6. A system for generating compressed air for at least one vehicle, comprising: an electric motor (301) arranged to generate a drive torque; a first coupling means (304) arranged to selectively assume a first state in which the electric motor (301) is connected to a first compressor (303) or a second state in which the electric motor (301) is disconnected from the first compressor (303); second coupling means (308) arranged to selectively assume a first state in which the electric motor (301) is connected to a second compressor (307) or a second state in which the electric motor (301) is disconnected from the second compressor (307); control means (320) configured to control transitions of the first coupling means (304) between the first state and the second state and between the second state and the first state, and transitions of the second coupling means (308) between the first state and the second state and between the second state and the first state, so that the driving torque generated by the electric motor (301) is selectively provided to the first compressor (303) or the second compressor (307), or is simultaneously provided to the first compressor (303) and the second compressor (307); A system comprising:

7. A main reservoir (311) arranged to store compressed air generated by the first compressor (303) and the second compressor (307); and a pressure sensor means arranged to measure a pressure value inside the main reservoir (311), 7. The system of claim 6, wherein the pressure value in the main reservoir (311) is configured to take on pressure values ​​over time within a range of pressures including a null value, a first predetermined pressure value (Pmin) greater than the null value, and a second predetermined pressure value (Pmax) greater than the first predetermined pressure value (Pmin).

8. When the pressure value measured by the pressure sensor means is less than the first predetermined pressure value (Pmin), the control means (320) controlling the first coupling means (304) so ​​that the first coupling means (304) is in a first state connecting the electric motor (301) to the first compressor (303); controlling the second coupling means (308) so that the second coupling means (308) is in a first state connecting the electric motor (301) to the second compressor (307); maintaining the first coupling means (304) in its first state and maintaining the second coupling means (308) in its first state until the pressure value measured by the pressure sensor means reaches the first predetermined pressure value (Pmin); The system of claim 7 configured to:

9. When the pressure value measured by the pressure sensor means is equal to the first predetermined pressure value (Pmin) or is between the first predetermined pressure value (Pmin) and the second predetermined pressure value (Pmax), The control means (320) controlling the second coupling means (308) to be in a first state in which the second coupling means (308) connects the electric motor (301) to the second compressor (307) and controlling the first coupling means (304) to be in a second state in which the first coupling means (304) disconnects the electric motor (301) from the first compressor (303); maintaining the second coupling means (308) in its first state and the first coupling means (304) in its second state until the pressure value measured by the pressure sensor means is equal to or greater than the second predetermined pressure value (Pmax), the second predetermined pressure value (Pmin) being greater than the first predetermined pressure value (Pmin); Or, controlling the first coupling means (304) to be in a first state in which the first coupling means (304) connects the electric motor (301) to the first compressor (303) and controlling the second coupling means (308) to be in a second state in which the second coupling means (308) disconnects the electric motor (301) from the second compressor (307); maintaining the first coupling means (304) in its first state and the second coupling means (308) in its second state until the pressure value measured by the pressure sensor means is equal to or greater than the second predetermined pressure value (Pmax), the second predetermined pressure value (Pmin) being greater than the first predetermined pressure value (Pmin); 9. The system of claim 7 or claim 8, configured to selectively perform:

10. The method according to claim 1, wherein the control means (320) is configured to measure a first total operating time of the first compressor (303) and to measure a second total operating time of the second compressor (307); when the pressure value measured by the pressure sensor means is equal to the first predetermined pressure value (Pmin) or is included between the first predetermined pressure value (Pmin) and the second predetermined pressure value (Pmax) and the first total operating time of the first compressor (303) is longer than the second total operating time of the second compressor (307), The control means (320) controlling the second coupling means (308) to be in a first state of the second coupling means (308) connecting the electric motor (301) to the second compressor (307) and controlling the first coupling means (304) to be in a second state of the first coupling means (304) disconnecting the electric motor (301) from the first compressor (303); maintaining the second coupling means (308) in its first state and maintaining the first coupling means (304) in its second state until the pressure value measured by the pressure sensor means is equal to or greater than the second predetermined pressure value (Pmax), the second predetermined pressure value (Pmin) being greater than the first predetermined pressure value (Pmin); It is configured as follows: when the pressure value measured by the pressure sensor means is equal to the first predetermined pressure value (Pmin) or is included between the first predetermined pressure value (Pmin) and the second predetermined pressure value (Pmax) and the first total operating time of the first compressor (303) is shorter than the second total operating time of the second compressor (307), The control means (320) controlling the first coupling means (304) to be in a first state in which the first coupling means (304) connects the electric motor (301) to the first compressor (303) and controlling the second coupling means (308) to be in a second state in which the second coupling means (308) disconnects the electric motor (301) from the second compressor (307); maintaining the first coupling means (304) in its first state and the second coupling means (308) in its second state until the pressure value measured by the pressure sensor means is equal to or greater than a second predetermined pressure value (Pmax) that is greater than the first predetermined pressure value (Pmin); The system according to claim 7 or claim 8, configured to:

11. The method according to claim 1, wherein the control means (320) is configured to measure a first total operating time of the first compressor (303) and to measure a second total operating time of the second compressor (307); The control means (320) preventing operation of the first compressor (303) for a first inhibit time period when the first total operating time of the first compressor (303) is greater than the second total operating time of the second compressor (307); preventing operation of the second compressor (307) for a second inhibit time period when the first total operating time of the first compressor (303) is less than the second total operating time of the second compressor (307); The system according to claim 7 or claim 8, configured to:

12. When, during the first suppression time period, the pressure value measured by the pressure sensor means is equal to the first predetermined pressure value (Pmin) or is between the first predetermined pressure value (Pmin) and the second predetermined pressure value (Pmax), The control means (320) controlling the second coupling means (308) to be in a first state in which the second coupling means (308) connects the electric motor (301) to the second compressor (307), and controlling the first coupling means (304) to be in a second state in which the first coupling means (304) disconnects the electric motor (301) from the first compressor (303); maintaining the second coupling means (308) in its first state and maintaining the first coupling means (304) in its second state until the pressure value measured by the pressure sensor means is equal to or greater than the second predetermined pressure value (Pmax), the second predetermined pressure value (Pmin) being greater than the first predetermined pressure value (Pmin); It is configured as follows: during the second suppression time period, when the pressure value measured by the pressure sensor means is equal to the first predetermined pressure value (Pmin) or is between the first predetermined pressure value (Pmin) and the second predetermined pressure value (Pmax), The control means (320) controlling the first coupling means (304) to be in a first state in which the first coupling means (304) connects the electric motor (301) to the first compressor (303) and controlling the second coupling means (308) to be in a second state in which the second coupling means (308) disconnects the electric motor (301) from the second compressor (307); maintaining the first coupling means (304) in its first state and the second coupling means (308) in its second state until the pressure value measured by the pressure sensor means is equal to or greater than a second predetermined pressure value (Pmax) that is greater than the first predetermined pressure value (Pmin); The system of claim 11 configured to:

13. The control means (320) is configured to define a first time interval during which operation of the first compressor (303) is prevented and a second time interval during which operation of the second compressor (307) is prevented, the first time intervals and the second time intervals being arranged alternately in time with each other, when, during one of the first time intervals, the pressure value measured by the pressure sensor means is equal to the first predetermined pressure value (Pmin) or is between the first predetermined pressure value (Pmin) and the second predetermined pressure value (Pmax), The control means (320) controlling the second coupling means (308) to be in a first state in which the second coupling means (308) connects the electric motor (301) to the second compressor (307), and controlling the first coupling means (304) to be in a second state in which the first coupling means (304) disconnects the electric motor (301) from the first compressor (303); maintaining the second coupling means (308) in its first state and maintaining the first coupling means (304) in its second state until the pressure value measured by the pressure sensor means is equal to or greater than the second predetermined pressure value (Pmax), the second predetermined pressure value (Pmin) being greater than the first predetermined pressure value (Pmin); It is configured as follows: when, during one of the second time intervals, the pressure value measured by the pressure sensor means is equal to the first predetermined pressure value (Pmin) or is between the first predetermined pressure value (Pmin) and the second predetermined pressure value (Pmax), The control means (320) controlling the first coupling means (304) to be in a first state in which the first coupling means (304) connects the electric motor (301) to the first compressor (303) and controlling the second coupling means (308) to be in a second state in which the second coupling means (308) disconnects the electric motor (301) from the second compressor (307); maintaining the first coupling means (304) in its first state and the second coupling means (308) in its second state until the pressure value measured by the pressure sensor means is equal to or greater than the second predetermined pressure value (Pmax), the second predetermined pressure value (Pmin) being greater than the first predetermined pressure value (Pmin); The system according to claim 7 or claim 8, configured to:

14. When the pressure value measured by the pressure sensor means is equal to or greater than the second predetermined pressure value (Pmax) which is greater than the first predetermined pressure value (Pmin), The control means (320) controlling the first coupling means (304) to be in a second state of the first coupling means (304) that decouples the electric motor (301) from the first compressor (303); controlling the second coupling means (308) to be in a second state of the second coupling means (308) that decouples the electric motor (301) from the second compressor (307); maintaining the first coupling means (304) in its second state and maintaining the second coupling means (308) in its second state until the pressure value measured by the pressure sensor means is equal to or less than the first predetermined pressure value (Pmin); The system according to claim 7 or claim 8, configured to:

15. When the pressure value measured by the pressure sensor means is equal to or greater than the second predetermined pressure value (Pmax), The control means (320) Driving the electric motor (301) to generate a null value driving torque; The system of claim 14 configured to:

16. When the pressure value measured by the pressure sensor means is less than the first predetermined pressure value (Pmin), The control means (320) Driving the electric motor (301) to generate a driving torque having a first torque value; The system according to claim 7 or claim 8, configured to:

17. When the pressure value measured by the pressure sensor means is between the first predetermined pressure value (Pmin) and the second predetermined pressure value (Pmax) which is greater than the first predetermined pressure value (Pmin), The control means (320) Driving the electric motor (301) to generate a driving torque having a second torque value less than or equal to the first torque value. The system of claim 16 configured to:

18. Equipped with air drying means, The air drying means comprises: receiving compressed air generated by the first compressor (303), receiving compressed air generated by the second compressor (307), and generating dry compressed air that is supplied to the main reservoir (311); The system according to any one of claims 6 to 8, configured to:

19. The electric motor (301), a first drive shaft (302) arranged to transmit a drive torque to the first compressor (303) via the first coupling means (304) and a first mechanical coupling (305); a second drive shaft (306) integral with the first drive shaft (302) and configured to transmit a drive torque to the second compressor (307) via the second coupling means (308) and a second mechanical coupling (309); The system according to any one of claims 6 to 8, comprising:

20. The electric motor (301) comprises a drive shaft (501) arranged to couple the first coupling means (304) and the second coupling means (308), The system further comprises a first pulley (505) and a second pulley (507); the first pulley (505) is arranged to be mechanically coupled to a shaft (504) of the first compressor (303), and the second pulley (507) is arranged to be mechanically coupled to a shaft (506) of the second compressor (307); 9. The system according to claim 6, wherein the first coupling means (502, 304) is configured to transmit a driving torque to the first pulley (505) by means of at least one drive belt (508) and the second coupling means (503, 308) is configured to transmit a driving torque to the second pulley (507) by means of at least one drive belt (509).

21. A system as described in any of claims 6 to 8, wherein the first coupling means (304) is an electromechanical clutch and / or the second coupling means (308) is an electromechanical clutch.

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