EP0392414B1 - Axle with primary suspension and variable orientation - Google Patents

Abstract

Railway vehicle axle with primary suspension and variable orientation, rotating between two axle boxes and mounted on a frame, possessing a primary suspension comprising, for each of the axle boxes, two resilient blocks arranged on either side of the axle box, characterised in that the said blocks (5A, 5B) have an internal cavity connected, via a distribution system, to a source of fluid of adjustable pressure. <IMAGE>

Description

The present invention relates to a rail vehicle chassis comprising at least one axle mounted between two axle boxes connected to the body or bogie chassis by means of a primary suspension.

This primary suspension is often produced by two elastomer blocks with metal frames, arranged on either side of the axle box and bearing on the chassis.

Under certain operating conditions, and especially in curves, it is useful for the axles to be steerable so that they fit correctly in the curve, thus avoiding excessive wear of the wheels.

Are known, in particular from document FR-A-2 530 567, entirely mechanical orientation devices making it possible to orient the axles. These devices include spreaders and connecting rods directly actuating the axle boxes.

Axle orientation is therefore possible, due to the flexibility of the primary suspension.

However, these devices are complex and of uncertain reliability. Furthermore, these devices are bulky and difficult to accommodate inside an already well congested bogie.

Document CH-A-390 980 discloses a chassis of a railway vehicle comprising at least one steerable axle by means of two bellows supplied by a source of pressurized fluid. Each bellows rests on the one hand against the vehicle and on the other hand against an axle frame.

Document DE-A-3 123 858 discloses a running gear for a rail vehicle, with axles which can be oriented under the control of hydraulic cylinders. Each axle is mounted on two boxes connected to the chassis of the undercarriage by springs serving as primary suspension.

An object of the invention is to provide a chassis for a rail vehicle comprising at least one axle having a primary suspension and provided with reliable, simple and space-saving orientation means.

The subject of the invention is a chassis for a railway vehicle comprising at least one axle with variable orientation and rotating between two axle boxes, the chassis being provided with a primary suspension constituted, by axle box, of two elastic blocks supporting the load of the chassis and arranged on either side of the axle box, characterized in that said blocks have an internal cavity connected, by a distribution system, to a source of fluid at adjustable pressure.

• la figure 1 est une vue partielle schématique d'un châssis de véhicule ferroviaire selon l'art connu,
• la figure 2 est un schéma de principe qui montre l'orientation possible d'un essieu par rapport à un châssis quelconque,
• la figure 3 est une vue de dessus d'une partie de châssis selon l'invention,
• la figure 4 est une vue selon la ligne IV-IV de la figure 3, l'essieu étant en position d'orientation nulle,
• la figure 5 est une vue analogue, l'essieu étant orienté d'un angle + a.

An example of a chassis according to the invention is described below, with reference to the appended drawing in which:

• FIG. 1 is a partial schematic view of a chassis of a rail vehicle according to known art,
• FIG. 2 is a block diagram which shows the possible orientation of an axle with respect to any chassis,
• FIG. 3 is a top view of a chassis part according to the invention,
• FIG. 4 is a view along the line IV-IV of FIG. 3, the axle being in the zero orientation position,
• Figure 5 is a similar view, the axle being oriented at an angle + a.

Figure 1 shows schematically and in accordance with known art a bogie chassis 1 and an axle box 4 connected to the chassis by a primary suspension formed of two blocks 5A, and 5B, formed of an elastomer such as rubber 50 reinforced with metallic reinforcements 51.

In FIG. 2 are shown only a chassis 1 and a single axle 2 provided with its two wheels 3. The axle 2 can therefore be oriented by turning around a vertical axis Z of a value + a or - a by relative to a rest position corresponding to an axis Y perpendicular to the longitudinal axis X of the chassis.

Of course, in a curve, the other axle of a bogie or of a vehicle must be oriented by a value - a when the axle 2 is oriented by a value + a, and vice versa.

In Figure 3 are shown the frame 1, the axle 2 and its two wheels 3, but also two axle boxes 4 in which the axle rotates, four elastic blocks 5A, 5B, carrying the two boxes. According to the main characteristic of the invention, the blocks 5A, 5B constituting the primary suspension of the axle are each provided with a cavity 6, and with a distribution system 7 ensuring the supply of fluid to the cavities 6 by lines 8 and 9.

The two pipes 8 supply the cavities 6 of the two blocks 5B and the two pipes 9 supply the cavities 6 of the two blocks 5A.

Figure 4 shows in partially cut elevation, an axle box 4, two elastic elements 5A, 5B and their cavity 6, the element 5A being connected to a frame element 1A and the element 5B being connected to a chassis 1B. In this figure, the orientation of the axle is zero.

Figure 5 is a view similar to that of Figure 4, but in which the axle is inclined at an angle + a (see Figure 3) which corresponds to a displacement d of the axle box.

The axle is tilted as follows:
The railway comprises, at the entrance of a curve, a transmitter which sends a signal giving the radius of curvature. The vehicle includes a sensor which records this signal and processing means which transforms it into information i.

The distribution system 7 is connected to a hydraulic source delivering a fluid under pressure P and it is controlled by information i to supply either the pipes 8 or the pipes 9.

If the pipes 8 are supplied, the cavities 6 of the blocks 5A are then under pressure and they deform the blocks 5A in extension, while the blocks 5B are compressed (see FIG. 5).

The axle then inclines at an angle a varying between 0 and + a which represents a maximum inclination, and this as a function of the pressure delivered by the distribution system 7, this pressure being a function of the radius of curvature of the track . It is therefore possible to modulate the orientation angle of the axle as a function of the radius of curvature of the track.

Of course the signal can come from external signals other than the radius of curvature of the railway.

The invention makes it possible to produce an easily and securely orientable axle, remaining reliable over time, without significantly encumbering the usual environment of the axle.

Claims (2)

1. A rail vehicle frame including at least one steerable axle (2) that rotates between two axle boxes (4), the frame (1) being provided with a primary suspension constituted for each axle box by two resilient blocks (5A, 5B) supporting the load of the frame and disposed on either side of the axle box, characterized in that each of said blocks (5A, 5B) possesses an internal cavity (6) connected via a distribution system (7) to an adjustable pressure fluid source.
2. A rail vehicle frame according to claim 1, characterized in that the distribution system (7) is driven on the basis of information (i) given by means for processing a signal delivered by a sensor secured to the rail vehicle, the sensor being suitable for detecting signals transmitted by a transmitter disposed at the entrance to a curve of the railway track.

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