AC drive industrial switching locomotive

• US 6,267,062 B1
• Filed: 03/30/1999
• Issued: 07/31/2001
• Est. Priority Date: 03/30/1998
• Status: Expired due to Term

• Current Assignee: Hugh B. Hamilton Jr
• Original Assignee: Hugh B. Hamilton Jr
• Inventors: Hamilton, Hugh B. Jr.
• Primary Examiner(s): Morano, S. Joseph
• Assistant Examiner(s): Jules, Frantz F.
• Application Number:
  US09/281,035
• Time in Patent Office: 854 Days
• Field of Search: 105/26.05, 105/34.1, 105/35, 105/49, 105/26.1, 105/48, 105/61, 105/62.1, 105/67, 105/73, 105/76, 105/77, 105/78
• US Class Current: 105/26.05
• CPC Class Codes: B61C 7/04 Locomotives or motor railcars with two or more different kinds or types of engines, e.g. steam and IC engines
• CPC Class Codes: Y02T 30/00 Transportation of goods or passengers via railways, e.g. energy recovery or reducing air resistance

Abstract

The two axle locomotive of this invention includes a diesel engine directly coupled to a generator for generating power to a single electrical traction motor. Preferably, the drive motor is an AC traction motor which drives both axles of the locomotive using a single drive shaft assembly with a drive shaft affixed to an armature of the AC traction motor. Power to the AC traction motor is controlled by using a variable frequency alternating current control system. Auxiliary equipment power is also provided by the AC generator. In addition, by reversing the current in the AC traction motor the motor becomes an AC braking motor. Changes in the traction ability of each axle resulting from weight transfer between the two axles is automatically compensated for by the single drive shaft assembly. The suspension system includes a locomotive frame supported by the pair of axles using elastomeric springs, which also provides dynamic damping to limit the motion of the locomotive. The locomotive frame has a horizontal platform having two portions which allow the locomotive to be disassembled, shipped and reassembled at a remote location for its intended use.

Claims

1. A low-speed, high-traction industrial switching locomotive which automatically compensates for wheel slippage, weight transfer, and wheel diameter and track variations comprising:

a locomotive frame;

a first wheel axle mounted to said locomotive frame in a generally fixed directional relationship;

a second wheel axle mounted to said locomotive frame in a generally fixed directional relationship;

said first and second wheel axles being longitudinally spaced along a length of said locomotive frame to define a frame wheel base between the center lines of said first and second wheel axles and drive wheels carried by opposing ends of said first and second wheel axles for driving the locomotive on a rail;

an electrical drive motor having a motor mounted drive shaft affixed to said frame between said first and second axles having a rotor;

an electric power supply for supplying electrical power to said electrical drive motor and an electrical control for controlling the supply of electrical power to said electrical drive motor;

a first gear box connecting a first end of said rotor drive shaft to said first axle;

a second gear box connecting a second end of said rotor drive shaft to said second axle;

a first and second torque arm directly connected with said first and second gear boxes and said locomotive frame for stabilizing said gear boxes;

said wheel axles being interlocked through said drive shaft of said electrical drive motor and said respective first and second gear boxes to automatically proportion torque between said drive motor and axles depending on the relative traction between the axle wheels and said rail so that wheel slippage, weight transfer, and wheel diameter and track variations are automatically compensated for.

2. The locomotive of claim 1 wherein said electronic drive motor comprises an AC electrical motor, and said control includes an AC motor controller for supplying variable frequency electrical power to said AC drive motor.

3. The locomotive of claim 1 including a pair of opposing elastomeric springs connecting said wheel axles to said locomotive frame;

and

said pair of springs including a first spring connected between said axle and locomotive frame on one side of said axle, and a second spring connected between an opposing side of said axle and said frame and so that each said wheel axle is independently and softly sprung to said locomotive frame for increased traction.

4. The locomotive of claim 1 wherein said first torque arm is connected between said first gear box and said locomotive frame on a motor side of said first wheel axle, and said second torque arm is connected between said second gear box and said locomotive frame on a motor side of said second wheel axle so that said torque arms effectively resist pitch motions about said wheel axles to effectively eliminate unintentional uncoupling of said locomotive from a coupled railroad car.

5. The locomotive of claim 4 wherein said first and second torque arms are mounted offset in opposing directions with respect to a longitudinal center line of said locomotive to resist roll forces imparted to said gear boxes.

6. The locomotive of claim 5 wherein said first and second gear boxes include a gear reduction which reduces the speed of said locomotive to less than about 10 mph with high traction so that a smaller engine may be utilized.

7. The locomotive of claim 6 wherein said electronic drive motor comprises an AC electrical drive motor, and said control comprises a variable frequency AC drive which acts as a generator for supplying braking power to locomotive.

8. The locomotive of claim 1 wherein said power supply comprises an internal combustion engine, and an electrical generator driven by said engine.

9. The locomotive of claim 1 including a traction control for sensing the traction at said wheels of said wheel axles and adjusting the power supply to said electrical drive motor accordingly.

10. The locomotive of claim 1 wherein said first and second torque arms are mounted off-set from a longitudinal axis of said locomotive to resist roll motions.

11. The locomotive of claim 1 including resilient spring mounts mounting said first and second wheel axles to said locomotive frame when each said spring mount comprises:

a mounting block having an inboard and outboard side carried by each end of each of said first and second wheel axles;

a first resilient spring having a first end mounted to each said inboard side of said mounting blocks and on an in board side of said wheel axle, and a second end attached to said locomotive frame;

a second resilient spring having a first end attached to each said inboard side of said mounting blocks and on an out board side of said wheel axle and a second end attached to said locomotive frame;

said each of first and second springs being mounted between said mounting block and locomotive frame at an incline to resist pitch forces.

12. A low-speed, high-traction industrial switching locomotive which automatically compensates for wheel slippage, weight transfer, and track variations comprising:

a locomotive frame having an upper frame section and a lower frame section carried below said upper section;

an interface which allows mating said upper and said lower frame sections together forming said locomotive frame integral and separation of said upper and lower frame sections as separated independent units;

said upper and lower frame sections being of substantially equal weight and of a weight to allow said upper and lower sections when separated to be transported by truck on a highway and to be united at point of use as a locomotive;

said upper frame section having mounted thereon a diesel engine driving an AC generator which delivers AC current to an AC drive cabinet;

said lower frame section carrying an AC drive motor driving a pair of spaced gear boxes driving a pair of spaced wheel axles; and

,

a power connector for connecting and disconnecting the output of said controller with said motor.

13. A locomotive of claim 12 wherein said power connector comprises a power transfer cable.

14. The locomotive of claim 12 including resilient spring mounts mounting said wheel axles to said lower frame wherein each said spring mount comprises:

a mounting block carried by opposing ends of each of said first and second wheel axles;

a first resilient spring having a first end mounted to said mounting block on an in board side of said wheel axle, and a second end attached to said locomotive frame;

a second resilient spring having a first end attached to said mounting block on an out board side of said wheel axle and a second end attached to said locomotive frame;

said first and second springs being mounted between said mounting block and locomotive frame at an incline to resist pitch forces.

15. A low-speed, high-traction industrial switching locomotive comprising:

a locomotive frame comprising an upper frame and a lower frame section of substantially equal length;

a first wheel axle carried by said lower frame section;

a second wheel axle carried by said lower frame section;

said first and second wheel axles being longitudinally spaced along a length of and connected with said lower frame section to define a frame wheel base between the center lines of said first and second fixed wheel axles and drive wheels carried by opposing ends of said first and second wheel axles for driving the locomotive on a rail;

a drive motor connected with said lower frame section and a gear box carried by said wheel axles being connected by a single drive shaft for driving said wheel axles;

an interface frame mating said upper frame and said lower frame together; and

frame attachments for removably attaching said upper and lower frames together for use as a switching locomotive and allowing separation thereof for road transport.

16. The apparatus of claim 15 wherein said drive shaft has opposing ends extending from said drive motor in opposing directions along a longitudinal axis of said locomotive generally perpendicular to said wheel axles;

a power supply for supplying power to said drive motor and a drive control for controlling the supply of power to said drive motor;

a first gear box connecting a first end of said drive shaft to said first axle;

a second gear box connecting a second end of said drive shaft to said second axle;

at least one stabilizer element connected between each of said first and second gear boxes and said lower frame to resist pitch and roll forces on said gear boxes; and

said wheel axles being mechanically interlocked through said drive shaft and said respective first and second gear boxes to automatically shift torque from the drive motor to the axles depending on traction available between the axle wheels on the rails so that wheel slippage, weight transfer, and and track variations are automatically compensated for.

17. The apparatus of claim 15 wherein said drive motor comprises an electrical drive motor.

18. The locomotive of claim 15 including an electrical power transfer cable connectable across said interface frame between said upper and lower frame sections for delivering power to said electrical motor.

19. A low-speed, high-traction industrial switching locomotive comprising:

a locomotive frame;

a first wheel axle carried said locomotive frame;

a second wheel axle carried by said locomotive frame;

said first and second wheel axles being longitudinally spaced along a length of said locomotive frame to define a frame wheel base between the center lines of said first and second fixed wheel axles and drive wheels carried by opposing ends of said first and second wheel axles for driving the locomotive on a rail;

a drive motor carried by said frame between said first and second axles having a drive shaft for driving said wheel axles;

a first gear box carried by said first wheel axle connecting a first end of said motor drive shaft to said first axle;

a second gear box carried by said second wheel axle connecting a second end of said motor drive shaft to said second axle;

first and second torque arms directly connected to said first and second gear boxes and said locomotive frame for stabilizing said gear boxes;

a pair of opposing elastomeric springs connecting said wheel axles to said locomotive frame; and

said pair of springs including a first spring connected between said axle and locomotive frame on one side of said axle, and a second spring connected between an opposing side of said axle and said frame and so that each said wheel axle is independently and softly sprung to said locomotive frame for increased traction.

20. The locomotive of claim 19 wherein said first torque arm is connected between said first gear box and said locomotive frame on a motor side of said first wheel axle, and said second torque arm is connected between said second gear box and said locomotive frame on a motor side of said second wheel axle so that said torque arms effectively resist pitch motions about said wheel axles to effectively eliminate unintentional uncoupling of said locomotive from a coupled railroad car.

21. The locomotive of claim 20 wherein said first and second torque arms are mounted in opposing offset positions with respect to a longitudinal center line of said locomotive to resist roll forces imparted to said gear boxes.

22. The locomotive of claim 19 including resilient spring mounts mounting said first and second wheel axles to said locomotive frame wherein each said spring mount comprises:

a mounting block carried by opposing ends of each of said first and second wheel axles;

a first resilient spring having a first end mounted to said mounting block on an in board side of said wheel axle, and a second end attached to said locomotive frame;

a second resilient spring having a first end attached to said mounting block on an out board side of said wheel axle and a second end attached to said locomotive frame;

said first and second springs being mounted between said mounting block and locomotive frame at an incline do resist pitch forces.