AU2009202967B2

AU2009202967B2 - A variable steering railway bogie

Info

Publication number: AU2009202967B2
Application number: AU2009202967A
Authority: AU
Inventors: Scott Simson
Original assignee: Central Queensland University
Current assignee: Central Queensland University
Priority date: 2008-07-25
Filing date: 2009-07-23
Publication date: 2013-07-11
Anticipated expiration: 2029-07-23
Also published as: AU2009202967A1

Abstract

- 16 The present invention is directed to a variable steering railway bogie having a mounted vehicle body and including a frame, a plurality of wheelsets mounted to the frame wherein each of the wheelsets has an axle with two spaced apart wheels, 5 steering linkage means linking the wheelsets so that the wheelsets can cooperate to be in steering alignment, alignment means for positioning the body relative to the frame, variable steering means connecting the steering linkage means and the body, sensor means including sensors for monitoring the yaw angle and yaw velocity; and processor means for processing sensor means input and actuating the variable 10 steering means to control the steering of the wheelsets. 10 28 30 25 13 12 21 24 32 31 27 26

Description

A VARIABLE STEERING RAILWAY BOGIE FIELD OF INVENTION 5 The present invention relates to railways and railway bogies. BACKGROUND OF THE INVENTION A steering railway bogie includes a frame and two or more wheelsets connected to the frame. The frame is connected to a railway vehicle body. Each 10 wheelset comprises two spaced apart wheels operatively linked by an axle with or without independent rotation of the wheels. The wheelsets have freedom of movement to yaw relative to other wheelsets of the bogie so as to give an angle of steering. Each wheel often has a flange for safety but they rarely make contact with the rail. The tread of each wheel is slightly tapered having a non - linear conical 15 profile. The steering bogies minimise creep forces other than traction creep forces at the wheel rail contacts and evenly distributes the lateral curving forces between each wheelset to minimise wheel, rail and track damage. When a steering bogie encounters a bend, the wheelsets displace laterally on the rail so that the outer wheel has a higher contact angle to the rail relative to the 20 inner wheel causing the normal contact force of the wheelset on the rail to have a lateral component to the cross level of the rails. If the wheels of the wheelsets have dependent rotation there will also be longitudinal creepage differences between the wheels due to differences in rolling radius that generate a net yaw moment on the wheelset from creepage forces. Further to this a steering bogie wheelsets will 25 displace relative to each other to produce a steering angle and the bogie frame will displace in yaw rotation compared to the vehicle body to maintain tangential -2 alignment of the bogie to the track. In constant curvature track the steering angles between wheelsets and the yaw rotation angle for the bogie, which produce radial alignment of the wheelsets are a fixed ratio. For transition curve track sections where the curvature of the track changes 5 from tangent track to curved track the steering angle required is dependent on curvature under the bogie whilst the yaw rotation angle for the bogie is dependent on both the curvature under the vehicle and the change in curvature between the vehicle bogies. In this case the steering angle and the yaw rotation angle have a ratio that is different from the fixed ratio required in constant curves. This causes 10 problems in force steered or articulated steered bogies as the wheelsets are misaligned to the curve for curve transitions causing high wheel rail wear rates and high track shifting loads. Current steering bogie designs such as yaw relaxation, self steering, force steering, articulated steering and actuated wheelset yaw, do not control the yaw 15 rotation of the bogie. Current steering bogie designs rely on the wheelset creep forces to correctly yaw the bogie but under traction with low friction to adhesion ratios, the bogies are unable to control the bogie yaw. Passive steering bogies such as yaw relaxation, self steering are fully reliant on creep forces to actuate the steering angle of the bogie wheelsets and under high traction forces revert to.straight 20 alignment. Force steering and articulated steering bogies are partially reliant on creep forces for actuation and suffer partial steering angle lose under high tractions. Both force steering and articulated steering link the yaw angle between vehicle body and the bogie to the steering angle and hence during transition curve negotiation the wheelsets are yawed to the rail.

Actuated wheelset yaw bogie designs require sensor inputs and control which are independent of the wheel rail creep forces in order to control the steering angle of the wheelsets under traction with low friction to adhesion levels, Actuated wheelset yaw bogie designs require the placement of yaw actuators and sensors on 5 the bogie frame or across the bogies primary suspension. These locations are subject to higher impact loads during train operations than is experienced at or above the secondary suspension requiring more robust equipment. OBJECT OF THE INVENTION 10 It is an object of the present invention to provide an alternate bogie having an active bogie yaw control system and a variable active steering angle control of the wheelsets with all control actuators and sensors mounted at or above the secondary suspension. 15 SUMMARY OF THE INVENTION In one aspect the present invention broadly resides in a railway bogie with a mounted vehicle body including a frame; a plurality of wheelsets mounted to the frame, each of the wheelsets has an 20 axle with two spaced apart wheels; steering linkage means linking the wheelsets so that the wheelsets can cooperate to be in steering alignment alignment means for positioning the body relative to the frame; variable steering means connecting the steering linkage means and the body; -4 sensor means including sensors for monitoring the yaw angle and yaw velocity; and processor means for processing sensor means input and actuating the variable steering means to control the steering of the wheelsets. 5 Sensor means inputs preferably include bogie yaw displacement inputs from the alignment means, track transponder and velocity inputs. Preferably the sensor means inputs are processed with GPS input and track database of curvature and change in curvature. The variable steering means preferably includes a ram actuated by the 10 processor means in response to the processed input. The ram is preferably connected to and moves a linkage support that is attached to the steering linkage means. The steering linkage means preferably includes one or more linkage arms associated with each wheelset. The linkage arms are preferably pivotally attached to 15 each other so that the wheelsets can adopt a radial steering alignment when negotiating a curved track. The alignment means preferably includes one or more rams, each of which are attached to the frame and the body. More preferably the alignment means includes two rams attached to opposing longitudinal sides of the frame and body and 20 operatively cooperate to position the body with respect to the frame with actuation from the processor means. More preferably when the bogie travels a bend, the inner ram is shortened while the outer ram is lengthened to align the body with the frame to negotiate the bend with minimal yaw moment. The rams may be hydraulically or pneumatically operated. Actuation of the 25 rams may be by electrical or electromagnetic operation.

-5 The front and rear wheelsets preferably pivot about a vertical axis. More preferably the front and rear wheelsets preferably pivot about a vertical axis via coupled linkage arms so that the orientation of one wheelset is substantially opposite to the orientation of the other wheelset with respect to a longitudinal axis of the frame 5 when the bogie is traveling around a bend. Where there is a third intermediate wheelset, the intermediate wheelset preferably moves transversely with respect to a longitudinal axis of the frame and in line with the longitudinal axis of the wheelset. The intermediate wheelset preferably moves via two linkage arms attached to either side of the wheelset. Each of 10 intermediate wheelset linkage arms are preferably pivotally connected to adjacent linkage arms that are respectively attached to the front and rear wheelsets, The intermediate wheelset preferably moves transversely outwards from the radial centre of the bend that the bogie is traveling around. The processor means includes a processor that processes the input in 15 accordance with programming relevant to the bogie type. The programming can include information about the track, The processor preferably actuates the steering linkage means and the alignment means in a programmed coordinated manner. More preferably the processor either monitors the track position to control the 20 steering based on known track curvature or estimates track curvature from yaw velocities, yaw accelerations and train speed to control the steering.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the present invention can be more readily understood and put into practical effect, reference will now be made to the accompanying drawings wherein: 5 Figure 1 is a diagrammatic view of a two axle bogie of the first preferred embodiment where the bogie is in the straight position and using actuated bogie yaw and variable force steering permitting active control of both the bogie yaw angle and wheelset steering angle; Figure 2 is a diagrammatic view of a two axle bogie of the first preferred 10 embodiment where the bogie is in a transition curve position and using actuation to control bogie yaw position and actuation of the force steering linkage to control the wheelset steering angle; Figure 3 is a diagrammatic view of a two axle bogie of the first preferred embodiment where the bogie is in a constant curve position and using actuation to 15 control bogie yaw and the force steering linkage in the neutral position to control the wheelset steering angle; Figure 4 is a diagrammatic view of a generic two axle bogie showing steering and yaw angles when negotiating a curved track; Figure 5 is a diagrammatic view of a three axle bogie of the second preferred 20 embodiment where the bogie is in the straight position and using actuated bogie yaw and variable force steering permitting active control of both the bogie yaw angle and wheelset steering angle; Figure 6 is a diagrammatic view of a three axle bogie of the second preferred embodiment where the bogie is in a transition curve position and using actuation to -7 control bogie yaw and actuation of the force steering linkage to control the wheelset steering angle; and Figure 7 is a diagrammatic view of a three axle bogie of the second preferred embodiment where the bogie is in a constant curve position and using actuation to 5 control bogie yaw and the force steering linkage in the neutral position to control the wheelset steering angle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to figures 1, 2 and 3, there is shown a first preferred 10 embodiment of a two axle bogie 10 having a frame 11 with a front wheelset 12 and rear wheelset 13. The bogie 10 also has a vehicle body (not shown) attached to the frame 11. The front wheelset 12 and rear wheelset 13 have an axle 15 and tapered wheels 16. The front wheelset 12 has a first linkage arm 21 attached adjacent each end 15 of the axle 15. The first linkage arm 21 is pivotally connected by pivot 24 to a second linkage arm 25. The second linkage arm 25 is substantially rectangular and is also pivotally connected to a third linkage arm 26 at pivot 27. The third linkage arm 26 is attached adjacent each end of axle 15 of rear wheelset 13. The second linkage arm 25 is connected to the body linkage 28. The body linkage 28 is pivoted 20 to the steering ram 31 at the pivot 32, with the steering ram 31 fixed to the vehicle body and acting by rotating. In this way the front and rear wheelsets 12, 13 are coupled so that the orientation of the front wheelset 12 affects the orientation of the rear wheelset 13 in a manner that they cooperate to allow the bogie 10 to travel around a bend. With body linkage 28 the front and rear wheelsets 12, 13 and frame 25 11 are coupled to the steering ram 31, so the position of the vehicle body to the frame position adjusts by force the wheelset orientations to a steering angle (see figure 4) alignment that is adjustable with the steering ram 31. When the bogie 10 moves around a bend, the wheelsets 12, 13 follow the track so that the wheels 16 of the wheelsets 12, 13 contacts the rails at substantially 5 the same position on each wheel 16. As the front wheelset 12 follows the track the first linkage 21 causes the second linkage arm 25 to pivot which in turn causes the third linkage arm 26 to pivot and orientate the rear wheelset 13 in a position that is substantially opposite to the orientation of the first wheelset 12 with respect to the longitudinal axis of the frame 11. The second linkage arm 25 deflects transversely 10 because of the connection to body linkage 28 when the front wheelset 12 follows the track around a bend. The bogie 10 also has alignment rams 30 pivotally attached to the frame 11 and a steering ram 31 pivotally attached to the body linkage 28. The alignment rams 30 are positioned longitudinally on opposing sides of the frame 11. The alignment 15 rams 30 are also attached to the vehicle body at a position partway up an upright wall on either side of the vehicle body. Actuation of the alignment rams gives adjustment to the yaw angle (see figure 4) of the bogie. The steering ram 31 rotates the position of the pivot 32 changing positions of the linkages 21, 25, 26, 28 adjusting the steering angle between the wheelsets 12, 13. The steering ram 31 is 20 fixed to the vehicle body. The alignment rams 30 and the steering ram 31 are pneumatically, hydraulically or electrically operated in response to processed input. The alignment rams 30 provide bogie yaw displacement inputs to the processor. When the bogie 10 travels along the track a processor which processes the input, including bogie yaw displacement inputs from the alignment rams 30, in 25 accordance with its programming and actuates the alignment rams 30 so that the opposing alignment rams 30 cooperate to reduce misalignment of the bogie yaw displacement and to reduce instability in the bogie yaw displacement. When the bogie 10 moves around a bend, the inner alignment ram 30 shortens and the outer alignment ram 30 lengthens where inner and outer are with respect to the radial 5 centre of the bend. In a curve transition where the radius of curvature is changing the steering ram 31 adjusts the position of the pivot 32 changing the position of the linkages 21, 25, 26, 28 and the steering angle between wheelsets 12 and 13 to match the radial centre of the bend where the curve radius is changing. In constant radius curves the steering ram 31 places the pivots 32 in a neutral position that with 10 the linkages 21, 25, 26 and 28 set the steering angle between wheelsets 12 and 13 to match the radial centre of a constant radius bend. With actuation of the alignment rams 30, the vehicle body is positioned to be more in line with the frame 11 as it moves around the bend thereby minimizing lateral misalignment of the wheelset 12 and 13 to each other. Actuation of the 15 steering ram 31 positions the steering angle of the wheelsets 12 and 13. Together the actuation of alignment rams 30 and the steering ram 31 act such that the wheels 16 yaw misalignment to the rail is minimized, and wheels 16 lateral alignment is equalized, equalizing lateral track shifting forces and reducing the creepage of the wheels 16 on the rail maximising the available traction adhesion thereby reducing 20 wheel wear, rolling contact fatigue, flange contact and wheel slip. The alignment rams 30 and steering ram 31 may be actuated from input of train position using track transponder and velocity inputs or GPS input processed with a track database of curvature and change in curvature. The alignment rams 30 and steering ram 31 react to the calculated misalignment of the bogie 10 to the known rail curvature. This mode of operation is a full active control method and can be used to control anticipated bogie 10 behavior moving around a bond. Alternatively, the alignment rams 30 and steering ram 31 of a bogie 10 can be actuated in response to estimates of the track curvature and estimates of the change 5 in curvature where the yaw velocity and yaw acceleration together with track speed of the vehicle body is monitored to estimate curvature and change in curvature. This is the semi-active control method. The steering ram 31 is fixed to the vehicle body. The alignment rams 30 and the steering ram 31 are pneumatically, hydraulically or electrically operated in 10 response to processed input. With reference to Figures 5, 6 and 7, there is shown a second embodiment of the invention being a three axle bogie 50. Bogie 50 has front wheelset 52, intermediate wheelset 53 and rear wheelset 54. Bogie 50 also has a frame 51 and a vehicle body (not shown). 15 The wheelsets 52, 53, 64 have axles 56, tapered wheels 57. The front wheelset 52 has a first linkage arm 61 connected by pivot 62 to a second linkage arm 63. The second linkage arm 63 is attached to the intermediate wheelset 53. The second linkage arm 63 is connected by pivot 64 with the third linkage arm 65. The third linkage arm 65 is attached to rear wheelset 54. 20 When the first wheelset 52 follows the track the linkage arms 61, 63, 65 orientate the intermediate wheelset 53 and rear wheelset 54 to cooperate with the first wheelset 52 to move around the bend. The intermediate wheelset 53 can move transversely with respect to the longitudinal axis of the frame 51. The intermediate wheelset 53 is held with bushes to the frame 51 allowing the intermediate wheelset 25 53 to move transversely and in line with its axle 56, Where the bogie 50 is moving around the bend, the intermediate wheelset 53 is repositioned transversely outwards with respect to the radial centre of the bend, The rear wheelset 54 is orientated in the substantially opposite position to the front wheelset 52 as the bogie 50 moves around the bend. The second linkage arm 63 is connected by body linkage 67 to the 5 steering ram 71. The body linkage 67 Is pivoted to the steering ram 71 at the pivot 72, with the steering ram 71 fixed to the vehicle body and acting by rotating. The bogie 50 also has alignment rams 70 on opposing longitudinal sides of the frame 51. The alignment rams 70 are connected to the frame 51 and to the vehicle body, The alignment rams 70 provide bogie yaw displacement inputs to a 10 processor. The steering ram 71 rotates the position of the pivot 72 changing positions of the linkages 61, 63, 65, 67 adjusting the steering angle (see figure 4) between the wheelsets 52, 53 and 54 and radial lateral alignment of wheelset 53 to wheelset 52 and 54. The alignment rams 70 and steering ram 71 operate in substantially the same manner as described for the two axle bogie 10. 15 VARIATIONS It will of course be realised that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within 20 the broad scope and ambit of this invention as is herein set forth.

Claims

1. A railway bogie with a mounted vehicle body including a frame; a plurality of wheelsets mounted to the frame, each of the wheelsets has an axle with two spaced apart wheels; steering linkage means linking the wheelsets so that the wheelsets can cooperate to be in steering alignment; alignment means for positioning the body relative to the frame; variable steering means connecting the steering linkage means and the body; sensor means including sensors for monitoring yaw angle and yaw velocity; and processor means for processing sensor means input and actuating the variable steering means to control the steering of the wheelsets.

2. A railway bogie as claimed in claim 1, wherein sensor means inputs include bogie yaw displacement inputs from the alignment means, track transponder and velocity inputs.

3. A railway bogie as claimed in claim 1 or 2, wherein said sensor means inputs are processed with GPS input and track database of curvature and change in curvature.

4. A railway bogie as claimed in any one of the preceding claims, wherein the variable steering means includes a ram actuated by the processor means in .13 response to the processed input, said ram is connected to and moves a linkage support that is attached to the steering linkage means.

5. A railway bogie as claimed in any one of the preceding claims, wherein the 5 steering linkage means includes one or more linkage arms associated with each wheelset, the linkage arms are pivotally attached to each other so that the wheelsets can adopt a radial steering alignment when negotiating a curved track,

6. A railway bogie as claimed in any one of the preceding claims, wherein the 10 alignment means includes one or more rams, each of which are attached to the frame and the body.

7. A railway bogie as claimed in any one of the preceding claims, wherein the alignment means includes two rams attached to opposing longitudinal sides of the 15 frame and body and operatively cooperate to position the body with respect to the frame with actuation from the processor means.

8. A railway bogie as claimed in any one of the preceding claims, wherein the alignment means includes two rams attached to opposing longitudinal sides of the 20 frame and body and operatively cooperate to position the body with respect to the frame with abtuation from the processor means, when the bogie travels a bend the inner ram is shortened while the outer ram is lengthened to align the body with the frame to negotiate the bend with minimal yaw moment. - 14

9. A railway bogie as claimed in any one of the preceding claims, wherein the front and rear wheelsets pivot about a vertical axis.

10. A railway bogie as claimed in any one of the preceding claims, wherein the 5 front and rear wheelsets pivot about a vertical axis via coupled linkage arms so that the orientation of one wheelset is substantially opposite to the orientation of the other wheelset with respect to a longitudinal axis of the frame when the bogie is traveling around a bend. 10

11. A railway bogie as claimed in any one of the preceding claims, wherein a third intermediate wheelset moves transversely with respect to a longitudinal axis of the frame and in line with the longitudinal axis of the wheelset.

12. A railway bogie as claimed in any one of the preceding claims, wherein a third 15 intermediate wheelset moves transversely with respect to a longitudinal axis of the frame and in line with the longitudinal axis of the wheelset, the intermediate wheelset moves via two linkage arms attached to either side of the wheelset, each of the intermediate wheelset linkage arms are pivotally connected to adjacent linkage arms that are respectively attached to the front and rear wheelsets. 20

13. A railway bogie as claimed in any one of the preceding claims, wherein a third intermediate wheelset moves transversely with respect to a longitudinal axis of the frame and in line with the longitudinal axis of the wheelset, the intermediate wheelset moves via two linkage arms attached to either side of the wheelset, each of the 25 intermediate wheelset linkage arms are pivotally connected to adjacent linkage arms - 15 that are respectively attached to the front and rear wheelsets, said intermediate wheelset moves transversely outwards from the radial centre of the bend that the bogie is traveling around. 5

14. A railway bogie as claimed in any one of the preceding claims, wherein the processor means includes a processor that processes the input in accordance with programming relevant to the bogie type.

15. A railway bogie as claimed in any one of the preceding claims, wherein the 10 processor means includes a processor that processes the input in accordance with programming relevant to the bogie type, the programming includes information about the track.

16. A railway bogie as claimed in any one of the preceding claims, wherein the 15 processor means includes a processor that processes the input in accordance with programming relevant to the bogie type, the processor actuates the steering linkage means and the alignment means in a programmed coordinated manner.

17, A railway bogie as claimed in any one of the preceding claims, wherein the 20 processor either monitors the track position to control the steering based on known track curvature or estimates track curvature from yaw velocities, yaw accelerations and train speed to control the steering.

18. A railway bogie as substantially described herein with reference to and as 25 illustrated by the accompanying drawings.