The subject matter herein relates to rail vehicles, and, more particularly, to a kit for reconfiguring a locomotive from a first tractive effort configuration to a second tractive effort configuration.
A diesel-electric locomotive typically includes a diesel internal combustion engine coupled to drive a rotor of at least one traction alternator to produce alternating current (AC) electrical power. The traction alternator may be electrically coupled to power one or more electric traction motors mechanically coupled to apply torque to one or more axles of the locomotive. The traction motors may include AC motors operable with AC power, or direct current motors operable with direct current (DC) power. For DC motor operation, a rectifier may be provided to convert the AC power produced by the traction alternator to DC power for powering the DC motors.
AC-motor-equipped locomotives typically exhibit better performance and have higher reliability and lower maintenance than DC motor equipped locomotives. In addition, more responsive individual motor control may be provided in AC-motor-equipped locomotives, for example, via use of inverter-based motor control. However, DC-motor-equipped locomotives are relatively less expensive than comparable AC-motor-equipped locomotives. Thus, for certain hauling applications, such as when hauling relatively light freight and/or relatively short trains, it may be more cost efficient to use a DC-motor-equipped locomotive instead of an AC-motor-equipped locomotive.
For relatively heavy hauling applications, diesel-electric locomotives are typically configured to have two trucks including three axles per truck, where the three axles include one or more powered axles and one or more nonpowered axles. Each powered axle of the truck is typically coupled, via a gear set, to a respective motor mounted in the truck near the axle. Each axle is mounted to the truck via a suspension assembly that typically includes one or more springs for transferring a respective portion of a locomotive weight (including a locomotive body weight and a locomotive truck weight) to the axle while allowing some degree of movement of the axle relative to the truck.
A locomotive body weight is typically configured to be about equally distributed between the two trucks. The locomotive weight is usually further configured to be symmetrically distributed among the axles of the trucks. For example, a conventional locomotive weighing 420,000 pounds is typically configured to equally distribute weight to the six axles of the locomotive, so that each axle supports a force of 420,000/6 pounds per axle, or 70,000 pounds per axle.
Locomotives are typically manufactured to distribute weight symmetrically to the trucks and then to the axles of the trucks so that relatively equal portions of the weight of the locomotive are distributed to the axles. Typically, the weight of the locomotive and the adhesion capability of the locomotive determine a tractive effort capability rating of the locomotive. Accordingly, the weight applied to each of the powered axles multiply by the amount of friction or adhesion that can be developed to the powered axle determines a tractive effort capability of the corresponding powered axle. Consequently, the heavier a locomotive, the more tractive effort that it can generate. Additional weight, or ballast, may be added to a locomotive to bring it up to a desired overall weight for achieving a desired tractive effort capability. For example, due to manufacturing tolerances that may result in varying overall weights among locomotives built to a same specification, locomotives are commonly configured to be slightly lighter than required to meet a desired tractive effort capability, and then ballast is added to reach a desired overall weight capable of meeting the desired tractive effort rating. In conventional locomotive systems, the weight distribution among the powered axles and nonpowered axles is statically adjusted prior to shipment, and is not capable of being dynamically adjusted once the locomotive trip has begun.
Accordingly, a kit is needed that may be used to reconfigure a locomotive from a first tractive effort configuration to a second tractive effort configuration to dynamically affect a force applied through a locomotive powered axle or a locomotive nonpowered axle of a locomotive truck, so to dynamically adjust a weight distribution among the powered axle(s) and nonpowered axle(s).
One embodiment of the present invention provides a kit for reconfiguring a rail vehicle from a first tractive effort configuration to a second tractive effort configuration. The rail vehicle travels along a rail track, and includes a plurality of axles with a plurality of wheels in contact with the rail track. The first tractive effort configuration of the rail vehicle includes a fixed respective weight of the plurality of axles on the rail track prior to the rail vehicle traveling along the rail track. The kit includes a device to be respectively coupled to at least one axle in the second tractive effort configuration. Upon operatively coupling the device to the respective axle, the device selectively imparts a force through the at least one axle to dynamically vary the respective weight of the at least one axle on the rail track to affect a traction performance of the rail vehicle in the second tractive effort configuration traveling along the rail track.
Another embodiment of the present invention provides a method for reconfiguring a rail vehicle from a first tractive effort configuration to a second tractive effort configuration. The rail vehicle travels along a rail track, and includes a plurality of axles with a plurality of wheels in contact with the rail track. The first tractive effort configuration of the rail vehicle includes a fixed respective weight of the plurality of axles on the rail track prior to the rail vehicle traveling along the rail track. The method includes respectively coupling a device to at least one of the plurality of axles in the second tractive effort configuration. Upon operatively coupling the device to the respective axle, the device selectively imparts a force through the at least one axle to dynamically vary the respective weight of the at least one axle on the rail track to affect a traction performance of the rail vehicle in the second tractive effort configuration traveling along the rail track.
A more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. These drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope.
Reference will now be made in detail to the embodiments consistent with the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals are used throughout the drawings and refer to the same or like parts.
As illustrated in the exemplary embodiment of
Upon rotating the trucks 26,28 to the common alignment 42, the weight imparted by the powered axles (30,34) (36,40) on the rail track increases, while the weight imparted by the nonpowered axles (32) (38) on the rail track decreases, as compared to the respective values in the opposite alignment 43 arrangement. Although
Although the system 10 increases the traction performance of the locomotive 18 by rotating the trucks 26,28 to a common alignment 42, the system 10 may further include an optional device 27,29 (
As illustrated in the exemplary embodiment of
In an exemplary embodiment of the system 10, the respective device 27,29 is configured to increase the aggregate adhesion between the plurality of locomotive wheels 20 and the rail track, by selecting a characteristic of the normal force and dynamically affecting that characteristic. For example, a first axle 30 of the axles (30,32,34) (36,38,40) is coupled to a respective pair of wheels 20 in a slipping condition on the rail track. Additionally, a second axle 34 is coupled to a respective pair of wheels 20 in a non-slipping condition on the rail track. The respective device 27 is configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through the first axle 30 to control a creep condition of the respective pair of wheels 20, and reduce the slipping condition of the pair of wheels 20, for example. Additionally, the respective device 27 is configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through the second axle 32 to control a creep condition of the respective pair of wheels 20 and maintain the non-slipping condition of the pair of wheels 20, for example.
In a further exemplary embodiment, the plurality of axles (30,32,34) (36,38,40) may include a performance limited axle, and the respective device 27 may be configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through the performance limited axle to reduce a level of tractive effort passed through the performance limited axle. Examples of such a performance limited axle include: an axle having incurred a limitation in tractive effort attributed to a failure of a mechanical and/or electrical component of the locomotive 18, a thermally affected axle based on a temperature of the traction motor, a mechanical drive train and electric drive of the thermally affected axle exceeding a predetermined threshold, and a reduced capability axle providing limited traction effort efficiency.
In an additional exemplary embodiment of the system 10, the plurality of axles (30,32,34) (36,38,40) include a friction brake axle, where during the application of a locomotive brake such as an emergency air brake, an independent brake or a train brake, the respective device 27,29 is configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through the friction brake axle. The dynamic affect of the normal force 12 is based on an open loop or closed loop format, where the closed loop format involves a sensor coupled to the device 27,29 to detect a creep factor of the friction brake axle. The device 27,29 is configured to dynamically affect the normal force 12 based upon the creep factor received from the sensor. However, the open loop format involves the respective device 27,29 dynamically affecting the magnitude and/or direction of the normal force 12, until a particular parameter is achieved, such as a minimum increase in the tractive performance of the locomotive, for example.
In an additional exemplary embodiment of the system 10, the plurality of wheels 20 may include a flatspot wheel with a flat spot along a circumference of the wheel 20. The respective device 27,29 is configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through an axle 30 which has received the flatspot wheel 20 to impart an upward lift force on the flatspot wheel 20 to limit damage to the flatspot wheel, the rail track, and/or the locomotive 18. If the respective device 27,29 does not dynamically affect the magnitude and/or direction of the normal force 12 through the axle 30 and impart the upward lift force on the flatspot wheel 20, the flat spot along the flatspot wheel 20 would increase, and possibly lead to damage of the locomotive 18. In an additional exemplary embodiment of the system 10, the plurality of wheels 20 may include a locked wheel 20, received by a respective locked axle 30. In the exemplary embodiment, the respective device 27,29 is configured to dynamically affect the magnitude and/or direction of the normal force 12 applied through the respective locked axle 30 to impart an upward lift force on the locked wheel 20 to reduce a likelihood of locomotive derailment.
As discussed above, the system 10 is provided to affect a traction performance characteristic of the locomotive 18, and such traction performance characteristics may be based upon an operating characteristic of the locomotive 18. For example, the dynamic affect of the normal force 12 applied through the plurality of axles (30,32,34) (36,38,40) is configured to affect the traction performance of the locomotive 18 when the locomotive 18 is traveling over the rail track at a low speed lower than a speed threshold. Additionally, the traction performance affected by the system 10 may include a creep factor of the plurality of wheels 20 and a tractive effort of the plurality of wheels 20, for example. In another example, the dynamic affect of the normal force 12 applied the plurality of axles (30,32,34) (36,38,40) is configured to affect a wheel wear of the plurality of wheels 20, a ride quality of the locomotive 18, or a creep factor of the plurality of wheels 20 when the locomotive 18 is traveling over the rail track at a high speed greater than a speed threshold. The speed threshold may be any arbitrary speed, such as 12 miles per hour, for example. In yet another example, the dynamic affect of the normal force 12 applied through the plurality of axles (30,32,34) (36,38,40) is configured to dynamically control a respective weight of a pair of wheels 20 across an axle 30 which receives the pair of wheels 20, and/or to dynamically control a respective weight distribution between two axles 30,32, to affect a curve performance characteristic of the locomotive 18 when the locomotive 18 travels over a curve in the rail track. Although the exemplary embodiment refers to dynamically controlling the weight of the pair of wheels 20 across the axle 30, the system may dynamically control the weight of a pair of wheels across multiple axles. Additionally, although the exemplary embodiment refers to dynamically controlling a weight distribution between two axles 30,32, the system may be employed to dynamically control weight distribution between more than two axles.
In an additional exemplary embodiment of the system 10, the respective device 27,29 may dynamically affect a lateral force perpendicular to the normal force 12, where the lateral force is applied through a locomotive axle 30 in the locomotive 18 to enhance a curve performance characteristic of the locomotive 18 when the locomotive travels along a curve in the rail track.
In an additional exemplary embodiment of the system 10, upon a weight of the locomotive 18 having decreased by a weight of consumed locomotive fuel, the respective device 27,29 is configured to dynamically affect the respective normal force 12 passing through the powered axle 30 and the nonpowered axle 32 to increase a weight of the powered axle 30 to the weight of the powered axle 30 prior to the consumption of the locomotive fuel, and further to decrease a weight of the nonpowered axle 32 to a weight lower than a weight of the nonpowered axle 32 prior to the consumption of the locomotive fuel. In one exemplary embodiment, the weight of consumed locomotive fuel is determined by an algorithm performed by a locomotive controller, or a direct fuel level measurement within the fuel tank. When dynamically affecting the normal force 12 to increase the weight of the powered axle 30, the increase in the weight of the powered axle 30 is configured not to exceed a respective weight threshold for the powered axle 30.
In an additional exemplary embodiment of the system 10, the device 27,29 is configured to dynamically affect the force 12 applied through the plurality of axles (30,32,34) (36,38,40) to reduce an amount of ballast on the locomotive 18. The dynamic affect of the normal force 12 through the plurality of axles (30,32,34) (36,38,40) is utilized to provide a weight balance of the locomotive 18 across opposing ends, where the weight balance is configured to reduce a need to provide ballast on the locomotive.
In an additional exemplary embodiment of the system 10, the plurality of axles (30,32,34) (36,38,40) include powered axles (30,34) (36,40) and a nonpowered axle (32) (38), and the dynamic affect of the normal force 12 through the axles (30,32,34) (36,38,40) involves a weight shift to the powered axles (30,34) (36,40) for a limited time period to achieve one or more traction performance requirements of the locomotive 18. A maximum weight shift to the powered axles (30,34) (36,40) from the nonpowered axle (32,38) is performed within a minimum time period to minimize a structural impact on a locomotive 18 and rail track infrastructure. In an exemplary embodiment, such a maximum weight shift is 20,000 lbs, for example. In an additional exemplary embodiment, the plurality of wheels 20 have a respective plurality of diameters, where the respective device 27,29 is configured to dynamically affect the normal force 12 passed through the axles (30,32,34) (36,38,40) to normalize a wheel wear characteristic of the plurality of wheels 20 attributed to a disparity in the respective plurality of diameters.
The system 110 includes a coupling device 124, which is configured to couple the powered axles 112,115 to the nonpowered axle 114 to dynamically affect forces 128,129 applied through one of the powered axles 112,115 and nonpowered axle 114. One or more characteristics of the forces 128,129 applied through the powered axles 112,115 and nonpowered axle 114 are selected to affect the traction performance of the locomotive 116 as the locomotive travels along the rail track. In an exemplary embodiment, the one or more characteristics of the forces 128,129 are selected to optimize the traction performance of the locomotive 116 as the locomotive travels along the rail track.
In the exemplary embodiment of the system 110 illustrated in
As illustrated in the exemplary embodiment of
In the illustrated exemplary embodiment of
As discussed above and as illustrated in the exemplary embodiment of
As further illustrated in the exemplary embodiment of
As discussed in further detail in the embodiments below, instead of a rigid member, the coupling device 124 may take the form of a plurality of hydraulic actuators respectively coupled to the plurality of axles 112,114,115, where a compressed fluid within a first hydraulic actuator coupled to a first axle 112 is selectively supplied to a second hydraulic actuator coupled to a second axle 114 of the plurality of axles. In the exemplary embodiment, the compressed fluid within the second hydraulic actuator is configured to impart the secondary force 128 on the second axle 114. One of more characteristics of the secondary force 128 may be affected, including the magnitude and/or direction of the force 128, to increase a level of tractive effort passed through the second axle 114.
In the illustrated exemplary embodiment of
The hydraulic actuator 326′″ is configured to selectively impart the force through the respective locomotive axle 314′″ based upon the pressurized hydraulic fluid delivered from the pump 322′″ to the hydraulic actuator 326′″. The system 310′″ further includes a pair of displacement limits (not shown) coupled to the hydraulic actuator 326′″ to limit the force selectively imparted on the respective locomotive axle 314′″. A compliant member 340′″, such as a spring, for example, is disposed between the hydraulic actuator 326′″ and the respective locomotive axle 314′″ such that the hydraulic actuator 326′″ is coupled to the respective locomotive axle 314′″ in a compliant manner. Once the hydraulic actuator 326′″ selectively imparts the force through the respective locomotive axle 314′″, the compliant member 340′″ is configured to exert a reactive force on the respective locomotive axle 314′″. Although
In the exemplary embodiment illustrated in
Although
In addition to the embodiments discussed above, the device configured to selectively impart a force through a locomotive axle to control a respective weight of the locomotive axle on the rail track may be a mechanical actuator, an electro-mechanical actuator, a motor driven actuator, a manual driven actuator and a mechanical linkage actuator, coupled to a respective locomotive axle.
As discussed in the previous embodiments, a device may be coupled to a respective locomotive axle and the controller to selectively impart a force through the respective axle, to affect a tractive characteristic of the locomotive. The device may be any one of a hydraulic actuator, a pneumatic actuator, an electro magnetic actuator, a mechanical actuator, a motor driven actuator and a manually operated actuator, for example. In an exemplary embodiment of the system 500, the sensor 506 may be respectively coupled to the respective locomotive axle, to measure the force imparted by the device through the respective axle, and communicate the measured force to the controller 502. As further discussed in the previous embodiments of the present invention, such devices are configured to selectively impart a force through the respective axle in a direction away from the rail or toward the rail. The force may be based upon one or more dynamic characteristics of the hydraulic actuator or the pneumatic actuator, for example. In an exemplary embodiment of the system 500, the sensor 506 is coupled to the hydraulic actuator or the pneumatic actuator to measure the one or more dynamic characteristics of the hydraulic actuator or pneumatic actuator, where the dynamic characteristic may be the position or an applied pressure of the hydraulic actuator or the pneumatic actuator, for example.
Additionally, in the exemplary embodiment of
As further illustrated in the exemplary embodiment of
In addition to determining the static weight 503 of the plurality of wheels on the rail track, the controller 502 is configured to determine a respective target weight 522 of the plurality of wheels on the rail. As illustrated in the exemplary embodiment of
Upon determining the respective commands 524, the controller 502 is configured to communicate the respective commands 524 to the respective hydraulic actuator or pneumatic actuator respectively coupled to the plurality of axles and configured to impart a force through the respective axle in a direction either away from the rail or toward the rail, in response to the respective commands 524. Once the hydraulic actuator or pneumatic actuator impart the force through the respective locomotive axle, the dynamic weight of the plurality of wheels on the rail is modified to the respective target weight of the plurality of wheels on the rail, and one or more tractive characteristics of the locomotive is enhanced.
In an additional exemplary embodiment of the system 500, a controller 502 is configured to determine a respective dynamic weight command 524 of the plurality of axles on the rail track to dynamically shift a respective weight of the plurality of axles on the rail track based upon a rail track condition, a locomotive operating condition, an operator input, and/or a geographical input of a location along the rail track. In an exemplary embodiment of the system 500, the locomotive operating condition may be a locomotive speed traveling along the rail track, and such a locomotive speed below a speed threshold may prompt the dynamic weight command 524 of the plurality of axles on the rail tracks to shift a respective weight among the plurality of axles. In an additional exemplary embodiment, a notch level of a throttle may be the locomotive operating condition, and upon a locomotive operator increasing the notch level above a notch threshold (eg. 8), this may prompt the dynamic weight command 524 of the plurality of axles on the rail tracks to shift a respective weight among the plurality of axles. In an additional exemplary embodiment, a level of tractive effort may be utilized as the locomotive operating condition and may prompt the dynamic weight command 524 of the plurality of axles, for example. In an additional exemplary embodiment, a creep factor of the plurality of wheels, such as a slipping wheel condition or a non-slipping wheel condition, for example, may be utilized to prompt the dynamic weight command 524 of the plurality of axles, for example. In an additional exemplary embodiment, a level of fuel within a fuel tank of the locomotive may be utilized as the locomotive operating condition to prompt the dynamic weight command 524 of the plurality of axles, for example.
Based on the foregoing specification, the above-discussed embodiments of the invention may be implemented using computer programming or engineering techniques including computer software, firmware, hardware or any combination or subset thereof, wherein the technical effect is to dynamically determine a force applied through a plurality of locomotive axles in a locomotive configured to travel along a rail track in a travel direction. Any such resulting program, having computer-readable code means, may be embodied or provided within one or more computer-readable media, thereby making a computer program product, i.e., an article of manufacture, according to the discussed embodiments of the invention. The computer readable media may be, for instance, a fixed (hard) drive, diskette, optical disk, magnetic tape, semiconductor memory such as read-only memory (ROM), etc., or any transmitting/receiving medium such as the Internet or other communication network or link. The article of manufacture containing the computer code may be made and/or used by executing the code directly from one medium, by copying the code from one medium to another medium, or by transmitting the code over a network.
One skilled in the art of computer science will easily be able to combine the software created as described with appropriate general purpose or special purpose computer hardware, such as a microprocessor, to create a computer system or computer sub-system of the method embodiment of the invention. An apparatus for making, using or selling embodiments of the invention may be one or more processing systems including, but not limited to, a central processing unit (CPU), memory, storage devices, communication links and devices, servers, I/O devices, or any sub-components of one or more processing systems, including software, firmware, hardware or any combination or subset thereof, which embody those discussed embodiments the invention.
Another embodiment of the present invention provides a kit for reconfiguring a rail vehicle, such as a locomotive 18, for example, from a first tractive effort configuration to a second tractive effort configuration. As previously illustrated in
Additionally, the kit may include a mechanism configured to decouple an axle 32,38 of a respective truck 26,28 from the traction system of the locomotive 18. Such a mechanism may include any common tools appreciated by one of skill in the art which are utilized to remove one or more cables in the process of decoupling an axle 32,38 from a traction system of the locomotive 18, for example.
In an exemplary embodiment, the locomotive 18 in the first tractive effort configuration is an AC-powered locomotive with each axle (30,32,34) (36,38,40) of the pair of trucks 26,38 being coupled to a traction system of the AC-powered locomotive. In the exemplary embodiment, the locomotive 18 in the second tractive effort configuration exhibits a variable traction performance based on the mechanism having decoupled at least one (32) (38) nonpowered axle of the pair of trucks 26,28 from the traction system of the locomotive 18. Additionally, the variable traction performance is based on the dynamic variation of the respective weight of the powered axles (30,34) (36,4) of the pair of trucks 26,38 being coupled to the traction system.
The variable traction performance of the locomotive 18 in the second tractive effort configuration may be variably adjusted to an equivalent traction performance of a DC-powered locomotive with each axle of the pair of trucks being coupled to a traction system of the DC-powered locomotive. The pair of trucks 26,28 of the locomotive 18 in the second tractive effort configuration include at least one (30,34) (36,40) powered axles coupled to the traction system and at least one nonpowered axle (32) (38) decoupled from the traction system. The pair of trucks of the DC-powered locomotive include all axles being coupled to a traction system of the DC-powered locomotive. In the exemplary embodiment, the pair of trucks 26,28 of the locomotive 18 in the second tractive effort configuration respectively includes two powered axles (30,34) (36,40) and one non-powered axle (32) (38). The pair of trucks of the DC-powered locomotive respectively include three powered axles. In the exemplary embodiment, the variable traction performance of the four powered axles (30,34) (36,40) of the locomotive 18 in the second tractive effort configuration is variably adjusted to exhibit an equivalent traction performance of the six powered axles of the DC-powered locomotive based upon dynamic variation of the respective weight of the four powered axles (30,34) (36,40). In the specific exemplary embodiment discussed above, the respective weight of each powered axle (30,34) (36,40) of the locomotive 18 in the second tractive effort configuration is dynamically varied to produce one and a half times the tractive effort of each powered axle of the DC-powered locomotive, for example.
The kit for reconfiguring the rail vehicle may provide various advantages upon installation, such as enhancing a traction performance of the locomotive in a second tractive effort configuration traveling along the rail track.
While exemplary embodiments of the invention have been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes, omissions and/or additions may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.