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(11) | EP 0 161 729 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Bogie for a rail vehicle |
| (57) 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. |
[0001] The invention relates to a railway truck comprising a frame and at least two wheel sets yawlingly mounted thereto and journalled in axle bearings, said wheel sets being relatively coupled by means of a coupling mechanism for steering their yawling movements in opposite senses.
[0002] 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 rotary spindle of a railway truck. This coupling mechanism is practically not supported by springs.
[0003] 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 rotary spindle or one or more traction motors said mechanism being supported by springs for a substantial extent.
[0004] The railway truck according to the invention is characterized in that each of the two wheel sets is connected by means of linear 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.
[0005] The coupling means can now extend above the level of the level of the 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.
[0006] 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.
[0007] A coupling mechanism controlling with additionally high accuracy is obtained, when the coupling pivots are intercoupled by means of a coupling rod.
[0008] 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 pivotable connected to the frame about upwardly extending axes.
[0009] In the following description of the figures the invention will be illucidated, by way of example, with reference to a drawing.
[0010] 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.
[0011] 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 baering 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 linear 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.
[0012] As shown in Fig. 1 the coupling means consist of two cross rods 17 which cross one another and which intercouple levers 10 standing diagonally opposite one another and thus form a so-called cross anchor. Therefore in a rail bow 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 pivotal movement of the wheel sets 3 are steered in an opposite sense. In this way a stable bow setting of the wheel sets 3 is obtained.
[0013] A shown in fig. 1 the cross 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 truck spindle 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 couch work can bear through spring means 20 on the frame 2. One of the axles 10 is connected with the frame 2 by means of the rod 27 spherically pivotable at both ends, so that the breaking and tracting forces of the wheel sets 3 can be transferred onto the frame 2.
[0014] 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 lying poles 22 intercoupled by means of a coupling pivot 23 and having each, apart from said coupling pivot 23 formed by a linear pivot, two spherical lever pivots 17, by which they are secured to the levers 10.
[0015] 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.
[0016] Only one of the poles 22 is coupled by means of a pivotal rod 26 disposed in the perpendicular central plane 37 with the frame 2.
[0017] A railway truck 31 is distinguishe from the railway truck 21 particularly since a couple rod 29 extending transversely of the travelling direction X connects asymmetrical poles 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 of more readily adjusting without wringing, whilst the poles 22 cannot move with respect to the frame 2 in the direction X.
[0018] The length of the rod 29 is adjustable by means of a cap nmut 25 having right and left screwed ends in order to render the wheel rods 3 parallel to one another in their starting positions. The poles 22 are suspended from the frame 2 by means of hangers 29.
[0019] 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 via a hollow driving gear 33 the axle 19 extending through a hollow driving gear 33 via a coupling 34. The axles 19 are furthermore provided with disc breaks 35.
[0020] The rotary truck 31 can be connected to two downwardly directed supports 36 of a coach work by means of pivot rods 38 disposed symmetrically with respect to the central longitudinal plane 37 of the railway truck 31 in the direction X and engaging transverse arms 39 of pivotal levers 42 forming shafts 41 coupled by means of a transverse rod 40 on the frame 2.
[0021] 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.
[0022] 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.
[0023] The above-mentioned coupling means formed by rods 17 and poled 22 can be termed a cross anchor.
[0024] 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 (longitudinal) 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 poles 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 (perpendicular). 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 non-yieldably supported 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 jawl Q of one wheel set 3 signifies a practically equeal negative yawl S of the other wheel set 3. In a bow both wheels 5 found on the outer side of the bow 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 bearing guide, 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 bow. 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.
[0025] 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 yawl 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.