TECHNICAL FIELD

[0001] This relates generally to generators of electricity, and more specifically to generators for recovering energy from a train wheel.

BACKGROUND

[0002] Trains are provided with lights at the front and end of the train to provide visibility to the train occupants, as well as to other vehicles that may cross paths with the train in order to avoid collisions. However, lights are not provided along the sides of trains, such that their visibility is limited, which may make it difficult for to pedestrians and vehicles to see the trains at night. Problems with the wheel bearings or brakes of the train can be detected by temperature sensors placed on the wheels of the train. However, providing electrical power to the exterior of trains, especially the wheels, is made challenging by the layout of the train and the configuration of the wheels.

SUMMARY

[0003] According to an aspect, there is provided a generator for use with a train wheel, the generator comprising a housing having a mounting surface for fixedly mounting the housing to a train wheel, a stator fixedly attached to the housing, a rotor rotatably mounted to the stator, the rotor having an axis of rotation, and a counterweight attached to the rotor, the counterweight having a centre of gravity at a point offset from the axis of rotation of the rotor, the weight of the counterweight acting to maintain the rotor in a stationary position as the stator rotates with the housing, wherein the movement of the stator relative to the rotor generates electrical energy through the stator, and at least one of a light and a bearing monitoring system being electrically connected to the stator and powered by the electrical energy.

[0004] According to another aspect, the stator may comprise an armature and the rotor may comprise a permanent magnet, the rotation of the armature relative to the permanent magnet generating the electrical energy.

[0005] According to another aspect, the generator may further comprise an electricity storage device electrically connected to the stator and supplied by the electrical energy.

[0006] According to another aspect, both of the light and the bearing monitoring system may be electrically connected to the stator and powered by the electrical energy.

[0007] According to another aspect, the bearing monitoring system may comprise a temperature sensor.

[0008] According to another aspect, the generator may further comprise a notification indicator connected to the temperature sensor.

[0009] In other aspects, the features described above may be combined together in any reasonable combination as will be recognized by those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:

FIG. 1 is a perspective view of a train wheel having an electrical generator attached.

FIG. 2 is a cross-sectional view in isolation of the electrical generator shown in FIG. 1.

FIG. 3 is a front elevation view in section in isolation of the electrical generator shown in FIG. 1.

FIG. 4 is a perspective view in isolation of the mounting side of the electrical generator shown in FIG. 1.

FIG. 5 is a perspective view in isolation of the generator side of the electrical generator shown in FIG. 1.

FIG. 6 is a flow diagram of an application of the electrical generator. DETAILED DESCRIPTION

[0011] A generator generally identified by reference numeral 10, will now be described with reference to FIG. 1 through 5. [0012] Referring to FIG. 1, generator 10 for use with train wheel 12 has a housing 14 with a mounting surface 16 for fixedly mounting housing 14 to train wheel 12. Referring to FIG. 4 and 5, the depicted example shows a suitably type of mounting, where mounting surface 16 is a flange that extends outward from housing 14 with holes that allow the flange to be pin connected to train wheel 12, as shown in FIG. 1. Other types of mountings may also be used.

[0013] Referring to FIG. 2, a stator 18 is provided within housing 14 that is fixedly attached to housing 14. A rotor 20 is rotatably mounted to stator 18 and has an axis of rotation 22. A counterweight 24 is attached to rotor 20, counterweight 24 having a centre of gravity 40 (shown in FIG. 3) at a point offset from axis of rotation 22 of rotor 20. The weight of counterweight 24, due to gravity, acts on counterweight 24 to maintain rotor 20 in a stationary position as stator 18 rotates with housing 14. The shape of counterweight 24 may be selected to offset the centre of gravity 40 from rotor 20 as far as possible in order to provide more resistance against the movement of rotor 20. It will be understood that the terms "stator" and "rotor" generally refer to a stationary element and a rotating element. However, this designation will depend on the frame of reference. In the depicted embodiment, rotor 20 is held stationary by counterweight 24, while stator rotates with train wheel 12.

[0014] The movement of stator 18 relative to rotor 20 generates electrical energy that can be electrically transmitted to power connected devices. In one embodiment, rotor 20 may be provided as a permanent magnet that rotates relative to stator 18, which may, for example, have an armature 19 such as a wire coil that rotates with stator 18. Rotor 20 may be designed to be outside of stator 18 as shown, or within stator 18. As rotor 20 is held stationary by counterweight 24, the rotation of the armature 19 relative to the permanent magnet generates electrical energy in armature 19. It will be understood that the potential difference may also be generated by the rotation of a first electrical connection 26 connected to stator 18 and a second electrical connection 28 connected to rotor 20. In this example the movement of stator 18 relative to rotor 20 generates a potential difference between first and second electrical connections 26 and 28. The electrical energy generated by the movement of stator 18 relative to rotor 20 can be used to do power lights 30, a bearing monitoring system 32, charge an electrical storage device 34, or any combination of these functions. Electrical storage device 34 may be used in combination with the other features to allow the various components continue operating even after the train has stopped. In the depicted embodiment, bearing monitoring system 32 is a temperature sensor that is connected to lights 30, which are also used as a notification indicator to warn against bearing failure. The notification indicator 30 may take various forms, and may be visual, auditory, or may have a wireless transmission function to communicate temperature warnings to remote devices. For example, a processor may be used that causes lights 30 to display a different colour, or a particular partem if an alarm condition is detected. In another example, there may be a wireless transmission function such as a Bluetooth™ connection or a short range radio frequency module. Bearing monitoring system 32 may be provided in order to provide a warning if the temperature of the wheel hub exceeds a predefined temperature, which may indicate a problem with a wheel bearing or brake. As shown, both light 30 and bearing monitoring system 32 are electrically connected to stator 20 and powered by the electrical energy generated by the device rotation. An electricity storage device 34 may also be supplied by the electrical energy.

[0015] In one example, referring to FIG. 6, generator 10 may be used to provide self- generated power a Railway Collision Avoidance System (RCAS) connected to the bearing cover bolts of a train car wheel. In this case a microcontroller 42 is provided that is powered by generator 10 and electricity storage device 34. Generator 10 may provide electricity through an AC/DC converter 44 and a regulator 46. Warning indicator lights 30 may be provided along the train cars to provide a visual warning system to other vehicles for collision avoidance. The microcontroller controls a predefined oscillation of the warning indicator lights 30 as well as monitoring the wheel bearing house temperature as measured by temperature sensor 32. Lights 30 may be high intensity LED lights. A clock 48 may also be provided to control the oscillation frequency of the lights 30 and the sampling interval of temperature sensor 32. The microcontroller may control a microcontroller brown out voltage and have brown out detector 50, and may further be programmed to use a low power sleep mode and watchdog timers to conserve electrical storage. The microcontroller may also use either an analogue to digital converter or a serial interface temperature monitor.

[0016] In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the elements is present, unless the context clearly requires that there be one and only one of the elements.

[0017] The scope of the following claims should not be limited by the preferred embodiments set forth in the examples above and in the drawings, but should be given the broadest interpretation consistent with the description as a whole.