EP0161729B1

EP0161729B1 - Bogie for a rail vehicle

Info

Publication number: EP0161729B1
Application number: EP85200769A
Authority: EP
Inventors: Wolfram De Steur
Original assignee: RMO-Werkspoor Services BV
Current assignee: RMO-Werkspoor Services BV
Priority date: 1984-05-14
Filing date: 1985-05-14
Publication date: 1987-07-22
Also published as: ATE28429T1; EP0161729A1; DE3560355D1; NL8401551A

Abstract

In order to steer yawling movements of wheel sets (3) of a railway truck (1) in opposite senses, the wheel sets (3) are intercoupled through two relatively spaced pivotal arms (7) each of which being coupled with an intercoupling mechanism.

Description

The invention relates to a railway truck comprising a frame and at least two wheel sets yawingly mounted thereto and journalled in axle bearings, said wheel sets being relatively coupled by means of a coupling mechanism for steering their yawing movements in opposite senses.
Such a railway truck is known from the British Patent specification 1.179.723. Therein the coupling mechanism is formed by two cross rods extending at the level of the wheel sets centrally across the railway truck, that is to say, they are located at the place where it is conventional to arrange the king pin of a railway truck. This coupling mechanism is practically unsprung.
The invention has for its object to provide a railway truck of the kind set forth comprising a coupling mechanism leaving in the centre of the railway truck space for a king pin or one or more traction motors said mechanism being suspended to a substantial extent.
The railway truck according to the invention is characterized in that each of the two wheel sets is connected by means of cylindrical pivots with two relatively spaced pivotal arms, each of which being pivotally connected through a spherical pivot with a middle part of an upwardly directed, associated lever, one end of which being pivotally connected by means of a spherical pivot with the frame and the other end being pivotally connected by means of a spherical pivot with coupling means of the coupling mechanism, said coupling means substantially extending on the same level as the other ends and coupling at least the diagonally opposed levers.
The coupling means can now extend above the level of axles of the wheel sets so that a traction motor can be arranged in the centre of the railway truck. Preferably, however, the top ends of the four levers are pivotally suspended to the frame and the coupling means extend below the level of the axles of the wheel sets.
A rigid coupling mechanism is obtained when the coupling means comprise two lying coupling elements relatively coupled by at least one coupling pivot, each element having besides said coupling pivot, furthermore at least two lever pivots for securing these coupling elements to the levers.
A coupling mechanism control with additionally high accuracy is obtained, when the coupling pivots are intercoupled by means of a coupling rod.
In order to create supplementary space for the traction motor in the centre of the railway truck and to build on low level, the railway truck embodying the invention is preferably characterized by two longitudinal rods arranged on both sides of the central, longitudinal plane for connecting the railway truck with a coach work, said longitudinal rods engaging transverse arms of pivotal levers intercoupled by means of a transverse rod and being pivotably connected to the frame about upwardly extending axes.
In the following description of the figures the invention will be illucidated, by way of example, with reference to a drawing.
The drawing schematically shows in:

Figs. 1, 2 and 6 each a perspective view partly broken away of a railway truck embodying the invention,
Fig. 3 a plan view of a preferred embodiment of a railway truck acoording to the invention in different wheel set positions,
Fig. 4 a schematical representation of the railway truck of Fig. 3 in a rail bow, and
Fig. 5 a side view of the railway truck of Fig. 3.

The railway truck 1 according to the invention comprises a frame 2 and two wheel sets, which are rotatably journalled in bearings 4. Rail wheels 5 of the wheel sets 3 run on rails 6. Each bearing 4 has a pivotal arm 7, which by means of a spherical pivot 8 is pivotally connected with a middle piece 9 of a standing lever 10, the top end 11 of which is pivotally suspended to a swan- neck 13 of the frame 2 by means of a spherical pivot 12, said neck supports through a spring packet 14 on the bearing 4. The bearings 4 of a wheel set 3 constitute cylindrical pivots, by means of which two relatively spaced pivotal arms 7 are connected with this wheel set. The lower end 15 of each lever 10 is connected by means of a spherical pivot 16 with coupling means.
As shown in Fig. 1 the coupling means consist of two rods 17 which cross one another and which intercouple levers 10 standing diagonally opposite one another and thus furm a so-called cross anchor. Therefore in a rail curve spherical pivots 16 can displace compulsorily one another with respect to the frame 2 in the direction of the arrows 18 or all of them just opposite to the indicated arrows 18, so that the yawing movement of the wheel sets 3 are in opposite senses. In this way a stable curve setting of the wheel sets 3 is obtained.
A shown in fig. 1 the rods 17 are located on a low level at least on a considerably lower level than the level of the axles 19 of the wheel sets 3, so that in the centre of the railway truck 1 space is available for a king pin not shown in fig. 1 for securing a coach work to a truck 1 and/or one or more traction motors not shown in fig. 1. The coach work can bear through spring means 20 on the frame 2. One of the axles 3 is connected with the frame 2 by means of the rod 26 spherically pivotable at both ends, so that the breaking and tracting forces of the wheel sets 3 can be transferred onto the frame 2.
The railway truck 21 of fig. 2 is identical to the railway truck 1 in a sense such that the coupling means now consist of two horisontal arms 22 intercoupled by means of a coupling pivot 23 and having each, apart from said coupling pivot 23 formed by a cylindrical pivot, two spherical lever pivots 17, by which they are secured to the levers 10.
During the displacement of the spherical pivots 16 in the direction of the arrows 18 the coupling pivot 23 moves in the direction of the arrow 24.
Only one of the arms 22 is coupled by means of a pivotal rod 26 disposed in the longitudinal central vertical plane 37 with the frame 2.
The railway truck 31 of fig.3 is distinguished from the railway truck 21 by a coupling rod 29 extending transversely of the travelling direction X and connecting asymmetrical arms 22, whilst the middle of the base 27 of each pole 22 is coupled with the frame 2 by means of a pivot rod 26. In this manner the coupling means 10 and 22 permit a more readily adjusting without torsion, since the arms 22 cannot move with respect to the frame 2 in the direction X.
The length of the rod 29 is adjustable by means of a cap nut 25 having right and left screwed ends in order to render the wheel sets 3 parallel to one another in their starting positions. The arms 22 are suspended from the frame 2 by means of hangers 291
Fig. 3 illustrates that owing to the invention a traction motor 32 can be arranged in the centre of the railway truck 21 at the level of the axles 19. This traction motor 32 drives the axle 19 by means of a quill drive 33 via a coupling 34. The axles 19 are furthermore provided with disc breaks 35.
The railway truck 31 can be connected to two downwardly directed supports 36 of a coach work by means of pivot rods 33 disposed symmetrically with respect to the central longitudinal vertical plane 37 of the railway truck 31 in the direction X and engaging transverse arms 39 of pivotal bell crank levers coupled 42 by means of a transverse rod 40, and pivatably connected onto the frame 2 about shafts 41.
Fig. 4 illustrates the swing movement of the wheel sets 3 in the displacement of the pivotal levers 16 and 23 in the direction of the arrows 18 and 24 respectively. The resulted relative displacement between the bearings 4 and the frame 2 is elastically absorbed by the springs 14.
Fig. 6 shows a railway truck 43, in which lower ends 44 of levers 10 are pivotally connected by means of pivots 12 with the frame 2, whilst their upper ends 45 are coupled by means of spherical pivots 16 with cross rods 17 which are located considerably above the level of the axles 19 and above a traction motor 32. The middle of the levers 10 is connected by means of pivots 8 to arms 7 of bearings 4.
The above-mentioned coupling means formed by rods 17 and arms 22 can be termed a cross anchor.
Hereinafter the six movements of the wheel sets 3 with respect to the frame 2 of the railway truck 31 will be discussed:

- The movement in X-direction (Iongitudiral) owing to the breaking and tracting forces. These forces are rigidly transferred by components 7, 8, 10, 12 and 16, 27 and 26 onto the frame 2. Consequently there is hardly movability in this X-direction.
- The movement in Y-direction (transverse). This relates to the guiding forces of the rail after deduction of the transverse driving forces of the wheel set 3 (axle 19 with the pair of wheels 5) in its supporting points on the rails 6 and the inertia forces at a transverse shock. In the railway truck 31 they are elastically resisted by the transverse rigidity of the spring packets 14 of helical springs and via the levers 10, by the arms 22 having a small mass, but ensuring a steering effect to the two wheel sets 3 owing to the intercoupling in pivot 23 with an initiating force in the Y-direction. A force originating from the moving coach work in the Y-direction does not affect the steering of the wheel sets 3, since this force does not have influence on the cross anchor.
- The movement in the Z-direction (vertical). This relates to the weight force via spring packet 15 onto the bearing 4. The cross anchor is not affected by this spring action. The unsprung mass is not increased by the cross anchor.
- The pivotal movement about the X-axis, the so-called rolling, can be attributed to movements in the Z-direction and is undetached from the action of the cross anchor.
- The pivotal movement about the Y-axis is the normal rotation of the wheel set 3 about its own axial line. The wheels are fixed to the axle 19.
- The pivotal movement about the Z-axis. At this yawling the cross anchor becomes active. Owing to the rigid coupling via the components 7,8,10,12 16,22 and 23, for example, a positive yaw Q of one wheel set 3 signifies a practically equeal negative yaw S of the other wheel set 3. In a curve both wheels 5 found on the outer side of the curve will stay back, whereas the two other wheels tend to move forwardly owing to the fixation of the wheels 5 to their axles 19 and owing to the difference in the path to be covered. In the conventional railway trucks the reaction against it mainly in X-direction of a wheel flange for example, a pivotal arm, comes then directly journalled in the frame of the railway truck, so that the wheels 5 are rubbed about the curve. In railway trucks according to the invention the cross anchor ensures the necessary reaction. The swinging tendencies of the two wheel sets 3 operate contrarily to one another and neutralize one another so that a slight outward effect is sufficient to give a so-called radial adjustment to the two wheel sets 3, that is to say that the wheel sets 3 are not longer rubbed in Y-direction along the rails 6, which results in lower wheel and rail wear. This necessary low effect can originate, for example, from hollow wheel surface profiles so that before the flange makes contact the wheel of the preceding wheel set will run on a larger running circle and thus tends both to swing from the rail away and to slide therefrom.

Moreover on a straight rail a cross anchor has a quieter run so that the railway truck can remain in operation about twice as long, before the wheels have to be trimmed. According to the invention the reaction against the wheel set yaw due to the balancing effect of levers 10 is divided among cross anchor and frame 2. Owing to the leverage of the levers 10 the cross anchor effect, however, remains complete.

Claims

1. A railway truck (1) comprising a frame (2) and two wheel sets (3) yawingly mounted thereto and journalled in axle bearings (4), said wheel sets (3) being relatively coupled by means of a coupling mechanism for steering their yawing movements in opposite senses, characterized in that each of the two wheel sets (3) is connected by means of the axle bearings (4) forming cylindrical pivots with two relatively spaced pivotal arms (7), each of which being pivotally connected through a spherical pivot (8) with a middle part (9) of an upwardly directed lever (10), one first end (11) of which being pivotally connected by means of a spherical pivot (12) with the frame (2) and the second end (15) being pivotally connected by means of a spherical pivot (16) with coupling means (17) of the coupling mechanism, said coupling means (17) substantially extending on the same level as said second ends (15) of the levers (10) and coupling at least the diagonally opposed levers (10).

2. A railway truck (1) as claimed in claim 1, characterized in that the top ends (11) of the four levers (10) are deflectably suspended to the frame (2) and the coupling means (17, 22) extend below the level of the axles (19) of the wheel sets (3).

3. A railway truck (1) as claimed in claim 1 or 2, characterized in that the coupling means comprise two horizontal coupling elements (22) intercoupled by means of at least one coupling pivot (23), each coupling element having, apart from said coupling pivot (23), at least two other lever pivots (16) for securing these coupling elements (22) to the second ends of said levers (10).

4. A railway truck (31) as claimed in claim 3, characterized in that the coupling pivots (23) are intercoupled by means of a coupling rod (29).

5. A railway truck (31) as claimed in anyone of the preceding claims, characterized in that the wheel sets (3) are coupled with the frame (2) by means of at least one coupling rod (26), which extends mainly in the longitudinal central, vertical plane (37).

6. A railway truck (31) as claimed in anyone of the preceding claims, characterized by two longitudinal rods (38) arranged one on each side of the longitudinal central vertical plane of the railway truck (31) for connecting the railway truck (31) with a coach work, said longitudinal rods (38) engaging transverse arms (39) of horizontal bell crank levers (42) intercoupled by means of a transverse rod (40) and being pivotably connected to the frame (2) about upwardly extending shafts (41).