US20160257321A1

US20160257321A1 - Decoupled pinion gear detection

Info

Publication number: US20160257321A1
Application number: US14/637,508
Authority: US
Inventors: Isaac Suwa Traylor; Gregory Raymond Kupiec; Dennis John Melas
Original assignee: Electro Motive Diesel Inc
Current assignee: Progress Rail Locomotive Inc
Priority date: 2015-03-04
Filing date: 2015-03-04
Publication date: 2016-09-08

Abstract

A railway machine comprising a first electrical traction motor, a first wheel assembly, a first gear assembly and a controller module is disclosed. The first gear assembly may include a first pinion gear rotatably engaged with a drive shaft of the first electrical traction motor. The first gear assembly may further include a first driven gear that may be rotatably engaged with the first pinion gear and also operatively coupled to the first wheel assembly. The controller module may observe a plurality of railway machine operating conditions, execute program instructions while the railway machine is being operated and may determine whether the first pinion gear is decoupled from the drive shaft of the first electrical traction motor.

Description

TECHNICAL FIELD

This disclosure generally relates to electrically powered railway propulsion assemblies and, more specifically, relates to systems and methods to detect decoupled pinion gears of electrically powered railway propulsion assemblies.

BACKGROUND

Generally speaking, an electrically powered railway propulsion assembly includes an electrical fraction motor, a wheel assembly and a gear assembly. The gear assembly further includes a pinion gear and a driven gear. The pinion gear is rotatably coupled with a drive shaft of the traction motor, while the driven gear is rotatably engaged with the pinion gear. Further, the driven gear is operatively coupled to the wheel assembly. As electrical energy is passed to the electrical traction motor, the traction motor drive shaft rotates, thereby converting the electrical energy to mechanical energy. This mechanical energy is then passed to the wheel assembly via the gear assembly, thereby rotating the wheel assembly and thus propelling a railway machine to which the electrically powered railway propulsion assembly is joined.
Maintaining proper coupling between the pinion gear and the electrical traction motor drive shaft is important to the operation of electrically powered railway propulsion assemblies. If the coupling between these two pieces is less than optimal, or non-existent, the electrically powered railway propulsion assembly may fail to propel the railway machine to which the propulsion assembly is joined. Accordingly, it is advantageous for railway machine owners, operators and maintenance personnel to know when the pinion gear is decoupled from the drive shaft of the traction motor.
One attempt to monitor an electrically powered propulsion assembly of a machine is disclosed in U.S. Pat. No. 8,886,378 (the '378 patent). The '378 patent is directed to a system and methods for monitoring whether the drive train of a material handling machine, such as, a sit-down counterbalanced forklift, a stand-up counterbalanced forklift, a stand-up narrow-aisle reach forklift and the like, is properly working. The '378 patent does so by providing the drive train with a device that monitors gear box speed in addition to a tool that measures the flow of electric charge to a motor. This information is then sent to a system that determines whether the linkages in the drive train are properly connected.
While arguably effective for its specific purpose, the '378 patent is related to material handling machines, namely forklifts, and in no way to railway machines. Moreover, the electrical propulsion assemblies of railway machines are subjected to substantially greater torques than a material handling machine. For example, the weight of the electrically powered propulsion assembly of a railway machine alone meets the total weight of a forklift in many instances. Adding in the weight of the remaining railway machine and the cargo that it hauls, the torque on the electrically powered propulsion assembly of a railway machine is orders of magnitude greater than the torque experienced by a forklift. Accordingly, the system to monitor the drive train of a forklift would not withstand the environment to which electrically powered railway propulsion assemblies are exposed.
The present disclosure is directed to overcoming one or more problems set forth above and/or other problems associated with the prior art.

SUMMARY

In accordance with one embodiment of the present disclosure, a railway machine comprising a first electrical traction motor, a first wheel assembly, a first gear assembly and a controller module is disclosed. The first gear assembly may include a first pinion gear rotatably coupled with a drive shaft of the first electrical traction motor. The first gear assembly may further include a first driven gear that may be rotatably engaged with the first pinion gear and also operatively coupled to the first wheel assembly. The controller module may observe a plurality of railway machine operating conditions, execute program instructions while the railway machine is being operated and may determine whether the first pinion gear is decoupled from the drive shaft of the first electrical traction motor.
In accordance with another embodiment of the present disclosure, a method to identify a decoupled pinion gear of an electrically powered railway propulsion assembly is disclosed. In a first step, a first rotational value of a first pinion gear of a first electrical traction motor may be detected. Next, a first electrical load of the first electrical traction motor may be detected. Then, the first rotational value may be sent to a controller module that observes a plurality of electrically powered railway propulsion assembly operating parameters, that executes program instructions while the electrical railway propulsion system is being operated and that determines whether the first pinion gear is decoupled from the drive shaft of the first electrical traction motor. Next, the first electrical load may be sent to the controller module. Finally, a determination may be made whether the first pinion gear is decoupled from the first electrical traction motor.
In accordance with another embodiment of the present disclosure, a method of notifying a railway machine operator that a pinion gear of a railway machine's electrically powered railway propulsion assembly is decoupled from a traction motor of the electrically powered railway propulsion assembly is disclosed. In a first step, a first rotational value of a first pinion of a first electrical traction motor of the electrically powered propulsion assembly may be detected. Next, a first electrical load of the first electrical traction motor of the electrical railway propulsion system may be detected. Then, the first rotational value may be sent to a controller module that observers a plurality of electrically powered railway propulsion assembly operating parameters, that executes program instructions while the electrical railway propulsion system is begin operated and that determines whether the first pinion gear is decoupled from the drive shaft of the first electrical traction motor. Next, the first electrical load may be sent to the controller module. In a next step, a determination may be made whether the first pinion gear is decoupled from the first electrical traction motor. Finally, a signal may be sent to an alarm system for indicating that the first pinion gear is decoupled from the first electrical traction motor, if the if the controller module determines that first pinion gear is decoupled from the first electrical traction motor.
These and other aspects and features of the present disclosure will be more readily understood when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION

FIG. 1 is a side, plan view of a railway machine constructed in accordance with the present disclosure.

FIG. 2 is a fragmentary, partially exploded, perspective view of an electrically powered railway propulsion assembly for use with the railway machine of FIG. 1.

FIG. 3 is a partially cut-away, perspective view of an electrically powered railway propulsion assembly for use with the railway machine of FIG. 1.

FIG. 4 is a schematic of a power system for use with the railway machine of FIG. 1 including rotational sensors and current sensors to detect decoupled pinion gears of electrically powered railway propulsion assemblies and used in conjunction with the electrically powered railway propulsion assembly of FIGS. 2 and 3.

FIG. 5 is a schematic of a monitoring system for use with the railway machine of FIG. 1 for detecting decoupled pinion gears of electrically powered railway propulsion assemblies and used in conjunction with the electrically powered railway propulsion assembly of FIGS. 2 and 3.

FIG. 6 is a flowchart depicting an exemplary method of identifying a decoupled pinion gear of an electrically powered railway propulsion assembly of a railway machine.

FIG. 7 is a flowchart depicting an exemplary method of notifying a railway machine operator that a pinion gear of a railway machine's electrically powered propulsion assembly is decoupled from the traction motor of the electrically powered railway propulsion assembly.

DETAILED DESCRIPTION OF THE DISCLOSURE

Referring now to the drawings, and with specific reference to FIG. 1, a railway machine is shown and generally referred to be reference numeral 10. While the railway machine 10 is generally depicted as a locomotive, it is to be understood that this is only exemplary, as the teaching of the present disclosure can be employed elsewhere as well. The railway machine 10 disclosed herein generally incorporates an operator section 12, a power section 14 and an ancillary equipment section 16. The power section 14 may include an engine, such as a diesel engine, mechanically coupled to an electrical power generating device. While not meant to be limiting, the electrical power generating device may be a direct current (i.e., “DC”) generator or and alternating current (i.e., “AC”) alternator. Alternatively, such railway machine 10 may not contain a power section, rather obtaining electrical energy from an electrical power source that is external to the railway machine 10. For example, the railway machine 10 may be electrically powered by an overhead line or a third-rail that is located next to or near a railway track.
The railway machine 10 may further include one or more trucks (a.k.a., “bogie”) 18 positioned below the operator section 12, power section 14 and ancillary equipment section 16 of the machine 10. The one or more trucks 18 may carry the weight of operator section 12, power section 14 and ancillary equipment section 16 of the railway machine 10. Further, and now while additionally referring to FIGS. 2 and 3, the one or more trucks 18 may further include an electrically powered railway propulsion assembly 20 that converts the electrical energy of the power section 14 to mechanical energy, thereby propelling the railway machine 10.
Now turning specifically to FIGS. 2 and 3, the electrically powered railway propulsion assembly 20 generally includes an electrical traction motor 22, a wheel assembly 24 and a gear assembly. The gear assembly 26 may include a pinion gear 28 and a driven gear 30. The pinion gear may be rotatably coupled to a drive shaft 32 of the electrical traction motor 22, while the drive gear 30 is rotatably engaged with the pinion gear 28, and further is operatively coupled to the wheel assembly 24. As electrical energy is passed from the electrical power generating device to the electrical traction motor 22, the traction motor drive shaft 32 rotates, thereby converting the electrical energy to mechanical energy. This mechanical energy is then passed to the wheel assembly 24 via the gear assembly, thereby rotating the wheel assembly 24 and thus propelling a railway machine 10 to which the electrically powered railway propulsion assembly 20 is joined.
Maintaining proper coupling between the pinion gear 28 and the electrical traction motor drive shaft 32 is important to the operation of electrically powered railway propulsion assemblies 20. If the coupling between these two pieces is less than optimal, or non-existent, the electrically powered railway propulsion assembly 20 may fail to propel the railway machine 10 to which the propulsion assembly is joined. Accordingly, it is advantageous for railway machine 10 owners, operators and maintenance personnel to know when the pinion gear 28 is decoupled from the drive shaft 32 of the electrical traction motor 22.
Referring now to FIGS. 4 and 5, a system that may monitor the decoupling of a pinion gear 28 from the drive shaft 32 of the electrical traction motor 22 of a railway machine 10 is generally referred to by reference numeral 34. This monitoring system 34 may include one or more rotational sensors 36 that are operatively associated the electrical traction motors 22. The rotational sensors 36 may monitor the rotational speed of the pinion gear 28 of the electrical traction motor 22 with which it is operatively associated. The system 34 may further include one or more current sensors 38 operatively associated with the one or more electrical traction motors 22. The current sensors 38 may measure an electrical load on the traction motor 22 to which each current sensor 38 is operatively associated.
Turning specifically now to FIG. 5, the rotational sensors 36 and current sensors 38 may be in electrical communication with a controller module 40. The controller module 40 may observe a plurality of the railway machine's 10 operating parameters, such as, for example, the signals from the rotational sensors 36 and the current sensors 38. Further, such controller module 40 may comprise a microprocessor having non-transitory computer readable storage medium having computer-executable program instructions thereon. Such controller module 40 therefore may execute program instructions while the railway machine is being operated. Furthermore, such controller module 40 may determine when a pinion gear 28 is decoupled from drive shaft 32 of the electrical traction motor 22 by comparing the signals it receives from a rotational sensor 36 and comparing it to the signal it receives from a current sensor 38.
For example, the controller module 40 may determine that a pinion gear 28 is decoupled from the drive shaft 32 of its respective traction motor 22 if the rotational value detected by the rotational sensor 36 is greater than zero, while the electrical load on the traction motor 22 measured by the current sensor 38 is negligible. Alternatively, the controller module 40 may determine that a pinion gear 28 is decoupled the drive shaft 32 of its respective traction motor 22 if the rotational value detected by the rotational sensor 36 is greater than zero, while the electrical load on the traction motor 22 measured by the current sensor 38 is negligible, and further if the rotational value detected by a second rotational sensor 36 operatively associated with a second electrical traction motor 22 is greater than zero, and electrical load associated with the second fraction motor 22 measured by a second current sensor 38 is also greater than zero.
The controller module 40 may be in electrical communication with an alarm system 42. This alarm system may be located in the operator station 12 of the railway machine 10. In the event the controller module 40 detects that a pinion gear 28 is decoupled from the drive shaft 32 of its respective traction motor 22, the controller module 40 may send a signal to the alarm system 42 to indicate that such an event has occurred.
Referring now to FIG. 6, steps of a method to identify a decoupled pinion gear 28 of an electrically powered railway propulsion 20 assembly is illustrated. At a step 44, a first rotational value of a first pinion gear 28 of a first electrical traction 22 motor may be detected. Then, at a step 46, the first electrical load of the first electrical traction motor 22 may be detected. Next, at a step 48, the first rotational value may be sent to a controller module 40 that observes a plurality of electrically powered railway propulsion assembly operating parameters, executes program instructions while the electrically powered railway propulsion assembly 20 is being operated, and that determines whether the first pinion gear is decoupled from the drive shaft of the first electrical fraction motor. In addition, at a step 50, the first electrical load may be sent to the controller module 40. Finally, at a step 52, the controller module may determine whether the first pinion gear 28 is decoupled from the first electrical traction motor 22.
A pinion gear of 28 may be decoupled from the first traction motor 22 if the first rotational value is greater than zero and the first electrical load is negligible. Additionally, the method may further include, detecting a second rotational value of a second pinion gear 28 of a second electrical traction motor 22, detecting a second electrical load of the second electrical traction motor 22, sending the second rotational value to the controller module 40 and sending the second electrical load to the controller module 40. In this alternative, a pinion gear 28 of a first traction motor 22 if the first rotational value is greater than zero, the first electrical load is negligible, the second rotational value is greater than zero and the second rotational value is greater than zero.
Turning now to FIG. 7, steps of a method of notifying a railway machine operator that a pinion gear 28 of a railway machine's electrically powered propulsion assembly 20 is decoupled from the traction motor 22 of the electrically powered railway propulsion assembly 20 are depicted. At a step, 54, a first rotational value of a first pinion gear 28 of a first electrical traction motor 22 of the electrically powered railway propulsion assembly 20 may be detected. At a step, 56, a first electrical load of the first electrical traction motor 22 of the electrically powered railway propulsion assembly 20 may be detected. Then, at a step 58, the first rotational value may be sent to a controller module 40 that observes a plurality of railway machine operating parameters, executes program instructions while the railway machine 10 is being operated, and that determines whether the first pinion gear 28 is decoupled from the drive shaft 32 of the first electrical traction motor 22. Next, at a step, 60, the first electrical load may be sent to the controller module 40. Then, at a step 62, the controller module 40 may determine whether the first pinion gear 28 is decoupled from the first electrical traction motor 22. If the controller module 40 determines that the first pinion gear 28 is decoupled from the first traction motor 22, then the controller module 40 may send a signal to the alarm system 42 indicating that such event has occurred.
A pinion gear of 28 may be decoupled from the first traction motor 22 if the first rotational value is greater than zero and the first electrical load is negligible. Additionally, the method may further include, detecting a second rotational value of a second pinion gear 28 of a second electrical traction motor 22, detecting a second electrical load of the second electrical traction motor 22, sending the second rotational value to the controller module 40 and sending the second electrical load to the controller module 40. In this alternative, a pinion gear 28 of a first traction motor 22 if the first rotational value is greater than zero, the first electrical load is negligible, the second rotational value is greater than zero and the second rotational value is greater than zero. Furthermore, the alarm system 42 for indicating that the first pinion gear is decoupled from the first electrical traction motor may be located in the operator section 12.

INDUSTRIAL APPLICABILITY

In operation, a system for detecting whether a pinion gear is decoupled from an electrically powered traction motor can find use in many industrial applications, such as in the electrically powered propulsion assemblies. More specifically, the system for detecting whether a pinion gear is decoupled from an electrically powered traction motor finds use in the electrically powered propulsion assemblies of railway machines, such as, locomotives.
Generally, an electrically powered railway propulsion assembly includes an electrical traction motor, a wheel assembly and a gear assembly. The gear assembly further includes a pinion gear and a driven gear. The pinion gear is rotatably coupled with a drive shaft of the traction motor, while the driven gear is rotatably engaged with the pinion gear. Further, the driven gear is operatively coupled to the wheel assembly. As electrical energy is passed to the electrical traction motor, the traction motor drive shaft rotates, thereby converting the electrical energy to mechanical energy. This mechanical energy is then passed to the wheel assembly via the gear assembly, thereby rotating the wheel assembly and thus propelling a railway machine to which the electrically powered railway propulsion assembly is joined.
During use, it is important to maintain proper coupling between the pinion gear and the drive shaft to which the pinion gear is associated. If the coupling between these two pieces is ineffective, or completely lacking, then the railway machine to which electrically powered railway propulsion assembly is attached may need to lessen its speed to operate safely, or may need to cease operation all together. Accordingly, it is beneficial for railway machine owners, operators and maintenance personnel to know if such decoupling events occur.
To keep such persons informed of the state of an electrical railway propulsion assembly, the current application discloses systems and methods to this end. Such a system may include a rotational sensor and a current sensor operatively associated with each electrical traction motor. These sensors may be in electrical communication with a controller module that observes a plurality of railway operating machine parameters. This controller module may determine whether a pinion gear decoupling event has occurred by comparing the signals sent from the rotational sensor and current sensor operatively associated with each motor, and in other instances may further compare the signals from a first motor to a second motor. In the instance a decoupling event occurs, the controller module may send a signal to an alarm system located in the operator section of the railway machine. It additionally may send a signal to such railway machine's owners and maintenance personnel.
The above description is meant to be representative only, and thus modifications may be made to the embodiments described herein without departing from the scope of the disclosure. Thus, these modifications fall within the scope of present disclosure and are intended to fall within the appended claims.

Claims

What is claimed is:

1. A railway machine, comprising:

a first electrical traction motor;

a first wheel assembly;

a first gear assembly, the first gear assembly including a first pinion gear and a first driven gear, the first pinion gear rotatably coupled with a drive shaft of the first electrical traction motor, the first driven gear rotatably engaged with the first pinion gear and operatively coupled to the first wheel assembly; and

a controller module that observes a plurality of railway machine operating parameters, executes program instructions while the railway machine is being operated and that determines whether the first pinion gear is decoupled from the drive shaft of the first electrical traction motor.

2. The railway machine according to claim 1, further including a first rotational sensor for monitoring the rotational speed of the first pinion gear, the first rotational sensor operatively associated with the first pinion gear, and a first current sensor for monitoring the electrical load on the first electrical fraction motor, the first current sensor operatively associated with the first electrical fraction motor.

3. The railway machine according to claim 2, wherein determining whether the first pinion gear is decoupled from the from the drive shaft of the first electrical traction motor includes determining whether the rotational value detected by the first rotational sensor is greater than zero and the electrical load on the first electrical traction motor is negligible.

4. The railway machine according to claim 3, further including an alarm system for indicating if the first pinion gear is decoupled from the drive shaft of the first electrical traction motor, and wherein the controller module sends a signal to the alarm system to indicate that the first pinion gear is decoupled from the drive shaft of the first electrical traction motor, if the rotational value detected by the first rotational sensor is greater than zero and the electrical load on the first electrical fraction motor is negligible.

5. The railway machine according to claim 2, further including a second electrical traction motor, a second wheel assembly, a second gear assembly including a second pinion gear rotatably engaged with a drive shaft of the second electrical traction motor and a second driven gear rotatably engaged with the second pinion gear and operatively coupled to the second wheel assembly, a second rotational sensor operatively associated with the second pinion gear, and a second current sensor for monitoring the electrical load of the second electrical traction motor operatively associated with the second electrical traction motor.

6. The railway machine according to claim 4, wherein determining whether the first pinion gear is decoupled from the from the drive shaft of the first electrical traction motor includes determining whether the rotational value detected by the first rotational sensor is greater than zero and the electrical load on the first electrical traction motor is negligible, determining whether the rotational value detected by the second rotational senor is greater than zero and the electrical load on the second electrical traction motor is greater than zero.

7. The railway machine according to claim 6, further including an alarm system for indicating if the first pinion gear is decoupled from the drive shaft of the first electrical traction motor, and wherein the controller module sends a signal to the alarm system to indicate that the first pinion gear is decoupled from the drive shaft of the first electrical traction motor, if the rotational value detected by the first rotational sensor is greater than zero and the electrical load on the first electrical fraction motor is negligible, and if the rotational value detected by the second rotational sensor is greater than zero and the electrical load on the second electrical traction motor is greater than zero.

8. A method to identify a decoupled pinion gear of an electrically powered railway propulsion assembly, comprising:

detecting a first rotational value of a first pinion gear of a first electrical traction motor;

detecting a first electrical load of the first electrical traction motor;

sending the first rotational value to a controller module that observes a plurality of electrically powered railway propulsion assembly operating parameters, executes program instructions while the electrically powered railway propulsion assembly is being operated, and that determines whether the first pinion gear is decoupled from the drive shaft of the first electrical fraction motor;

sending the first electrical load to the controller module; and

determining whether the first pinion gear is decoupled from the first electrical traction motor.

9. The method of identifying a decoupled pinion gear of an electrically powered railway propulsion assembly according to claim 8, wherein determining whether the first pinion gear is decoupled from the first electrical traction motor is in fact true, is if the first rotational value is greater than zero and the first electrical load is negligible.

10. The method of identifying a decoupled pinion gear of an electrically powered railway propulsion assembly according to claim 9, wherein the first rotational value is detected by a first rotational sensor operatively associated with the first pinion gear and the first electrical load is detected by a first current sensor operatively associated with the first electrical traction motor.

11. The method of identifying a decoupled pinion gear of an electrically powered railway propulsion assembly according to claim 8, further including detecting a second rotational value of a second pinion gear of a second electrical traction motor, detecting a second electrical load of the second electrical traction motor, sending the second rotational value to the controller module and sending the second electrical load to the controller module.

12. The method of identifying a decoupled pinion gear of an electrically powered railway propulsion assembly according to claim 11, wherein determining whether the first pinion gear is decoupled from the first electrical traction motor is in fact true, is if the first rotational value is greater than zero, the first electrical load is negligible, the second rotational value is greater than zero and the second rotational value is greater than zero.

13. The method of identifying a decoupled pinion gear of an electrically powered railway propulsion assembly according to claim 12, wherein the first rotational value is detected by a first rotational sensor operatively associated with the first pinion gear, the first electrical load is detected by a first current sensor operatively associated with the first electrical traction motor, the second rotational value is detected by a second rotational sensor operatively associated with the second pinion gear and the second electrical load is detected by a second current sensor operatively associated with the second electrical traction motor.

14. A method of notifying a railway machine operator that a pinion gear of a railway machine's electrically powered railway propulsion assembly is decoupled from a traction motor of the electrically powered railway propulsion assembly, comprising:

detecting a first rotational value of a first pinion gear of a first electrical traction motor of the electrically powered railway propulsion assembly;

detecting a first electrical load of the first electrical traction motor of the electrically powered railway propulsion assembly;

sending the first rotational value to a controller module that observes a plurality of railway machine operating parameters, executes program instructions while the railway machine is being operated, and that determines whether the first pinion gear is decoupled from the drive shaft of the first electrical traction motor;

sending the first electrical load to the controller module;

determining whether the first pinion gear is decoupled from the first electrical traction motor; and

sending a signal to an alarm system for indicating that the first pinion gear is decoupled from the first electrical fraction motor if the controller module determines that first pinion gear is decoupled from the first electrical traction motor.

15. The method of notifying a railway machine operator that a pinion gear of the railway machine's electrically powered railway propulsion assembly is decoupled from a traction motor of the electrically powered railway propulsion assembly according to claim 14, wherein determining whether the first pinion gear is decoupled from the first electrical traction motor is in fact true, is if the first rotational value is greater than zero and the first electrical load is negligible.

16. The method of notifying a railway machine operator that a pinion gear of the railway machine's electrically powered railway propulsion assembly is decoupled from a traction motor of the electrically powered railway propulsion assembly according to claim 15, wherein the first rotational value is detected by a first rotational sensor operatively associated with the first pinion gear and the first electrical load is detected by a first current sensor operatively associated with the first electrical traction motor.

17. The method of notifying a railway machine operator that a pinion gear of the railway machine's electrically powered railway propulsion assembly is decoupled from a traction motor of the electrically powered railway propulsion assembly according to claim 14, further including detecting a second rotational value of a second pinion gear of a second electrical traction motor in electrical communication with the electrical power source, detecting a second electrical load of the second electrical traction motor in electrical communication with the electrical power source, sending the second rotational value to the controller module and sending the second electrical load to the controller module.

18. The method of notifying a railway machine operator that a pinion gear of the railway machine's electrically powered railway propulsion assembly is decoupled from a traction motor of the electrically powered railway propulsion assembly according to claim 17, wherein determining whether the first pinion gear is decoupled from the first electrical traction motor is in fact true, is if the first rotational value is greater than zero, the first electrical load is negligible, the second rotational value is greater than zero and the second rotational value is greater than zero.

19. The method of notifying a railway machine operator that a pinion gear of the railway machine's electrically powered railway propulsion assembly is decoupled from a traction motor of the electrically powered railway propulsion assembly according to claim 18, wherein the first rotational value is detected by a first rotational sensor operatively associated with the first pinion gear, the first electrical load is detected by a first current sensor operatively associated with the first electrical traction motor, the second rotational value is detected by a second rotational sensor operatively associated with second pinion gear and the second electrical load is detected by a second current sensor operatively associated with the second electrical fraction motor.

20. The method of notifying a railway machine operator that a pinion gear of the railway machine's electrically powered railway propulsion assembly is decoupled from a traction motor of the electrically powered railway propulsion assembly according to claim 14, further including locating the alarm system for indicating that the first pinion gear is decoupled from the first electrical traction motor at the operator section.