The present invention relates to the railway sector, providing a displaceable rolling bogie for railway vehicles capable of adapting to the gauge of the track automatically.

The rolling bogies of railway vehicles incorporate the corresponding axles on which the wheels which move on the two rails forming the railway track are mounted. These wheels are separated from one another by a distance defined by the distance between the rails of the tracks along which it will move.

Since there are different configurations of railway tracks in which the distance between their two rails is different, such as the case within Spain with the so called "Renfe" track gauge and the so called "UIC" track gauge, variable gauge rolling bogies in which the change of track gauge is done automatically have been developed, this being the field to which the present invention is limited.

In this field of railway vehicles in which the distance between their wheels is automatically adapted to the distance between the two rails of the track along which they move, a distinction is made, for example, between those rolling bogies in which the axle body on which the wheels are mounted is fixed, and the wheels rotate on it, and those in which said axle body is rotary and rotates together with the wheels. For the case of railway vehicles with fixed axle, the solution disclosed by the Spanish Patent ES 2204483 of the same applicant as the present invention is known, for example.

In the case of railway vehicles with rolling bogie incorporating a rotary axle body, solutions as disclosed by the Spanish Patent ES 2184538 also belonging to the applicant of this invention, or the solution disclosed by document WO 2009/133227 of "Patentes Talgo", are known.

Likewise, another classification can be made depending on the system used for unlocking the wheels of the bogie during automatic change, there being fundamentally two types of solutions. On one hand, a solution is known in which the axial unlocking of the wheels with respect to the axle body is done by means of an actuation on latches travelling with the wheels. This actuation is established through locking/unlocking guides which form part of a fixed installation arranged on the ground close to the rails; so that when the railway vehicle reaches, in its path, the point in which the locking/unlocking guides are located, these guides will act on said latches, displacing them against retaining means to thus release the wheels, allowing the axial displacement of the wheels along the axle body to its new position. Such is the case of the solution proposed in the aforementioned document WO 2009/133227 and in the Japanese Patent JP2007314134 of "RTRI".

On the other hand, there are those solutions in which said unlocking is done as a result of a vertical movement of the axle body of the bogie, this movement being caused by gravity so that when the axle body is displaced by gravity, the automatic release of the locking means fixing the position of the wheels is produced, this is the case of the systems disclosed in French patent application publication FR 2383810 as well as in the aforementioned patent ES 2204483, and it is to what relates the present invention that proposes a variable gauge and automatic change bogie with a rotary axle body which, upon reaching the point of automatic change of the track gauge, said axle body falls by gravity, releasing the locking means of the wheels to allow the axial and automatic displacement of these along the axle body to the new position, in which they also automatically lock as the axle body returns to its initial position.

The solution proposed by the present invention has been designed to achieve an automatic change of track gauge in bogies of railway vehicles, including both electric and diesel self-driven as well as towed vehicles which may reach service speeds up to 300 km/h and axle loads up to 22.5 Tm., these values are given as the indication of the high performance required but not in a limiting sense.

The present invention relates to displaceable rolling bogie for railway vehicles according to claim 1.

As indicated in the claim, the locking system is by gravity, taking advantage of the vehicle weight itself to ensure that the locking pins fixing the position of the wheels are maintained in their sockets in the end support boxes.

When changing track gauge, there is a downwardly inclined track sector with the current gauge, reaching two additional rails on to which sheaves that are incorporated in the end support boxes take support and roll. When the end support boxes take support, the axle body starts dropping by gravity, the two locking pins coming out of each wheel, out of one of the two pairs of sockets of the end support boxes, which allows the displacement of the wheels along the axle body until reaching the position corresponding to the new track gauge, at which time the process is reversed; so that the locking pins now penetrate the other pair of sockets, which fixes the wheels in the new position of track gauge.

• Figure 1 is a view of a rotating axle body (1) with its wheels (4) arranged in a position corresponding to a track gauge.
• Figure 2 is a view such as Figure 1 but with the wheels (4) arranged in the position corresponding to the other track gauge.
• Figure 3 shows one end of the axle body (1) cut out at the locking pins (11 and 12) when the wheels (4) occupy the position corresponding to one of the two possible track gauges.
• Figure 4 shows one end of the axle body (1) in the same position as Figure 3 but now cut out at a longitudinal middle plane to see the components (5a, 5b and 5c) of the transmission (5).
• Figures 5 and 6 are respective views such as Figures 3 and 4, respectively, but in the position corresponding to the lowered axle body (1) and the unlocked pins (11 and 12).
• Figures 7 and 8 are respective views such as Figures 3 and 4, respectively, but now with the wheels (4) arranged in the position corresponding to the other track gauge.
• Figure 9 is a perspective view of one of the ends of the axle body (1) which allows seeing the pins (11 and 12) and their sockets (16 and 17).
• Figure 10 is also a perspective view such as Figure 9, but now with the sockets (16 and 17) already closed by their covers (22 and 23).
• Figure 11 is also a perspective view such as Figure 10, but now seen from the lower part to enable seeing the sheave (14) and the skid (25).
• Figure 12 shows the fundamental components of each safety latch in perspective.
• Figure 13 is a top and schematic plan view showing the installation fixed on the ground in the point where the track gauge changes.

The object of the present invention is a variable gauge rolling bogie, which, as seen in Figures 1 and 2, has a rotating axle body (1). On this rotating axle body (1) is mounted, on one hand, the corresponding transmission (2), in the case of driving bogies, the braking discs (3) and the rolling members formed by the wheels (4). On the other hand, the corresponding bogie frame is assembled through the end support boxes (10) and the primary suspension (13) made from a pack of helical springs located on the upper part of the support box (10) and responsible for transmitting the vertical loads. The transmission (2) directly drives the axle body (1), providing it with torque and rotation speed necessary for its movement.

The wheels (4) are mounted on to the axle body (1) with the radial clearance necessary to allow the transverse movement thereof on said axle body (1), this enabling the positioning of such wheels (4), according to the distance required by the separation between the rails (15) of the track along which it will drive.

Both wheels (4) are driven by the axle body (1) through respective couplings (5) which transmit the torque and the rotation to the wheels (4) for the different possible relative axial positions of said wheels (4) along the axle body (1).

Each coupling (5), as seen in Figures 4, 6 and 8, has three parts identified with the references (5a, 5b and 5c) which interact with one another by means of two conjugated gearing pairs formed therein. The inner most part (5a) is locked onto the axle body (1), being solid with it, and has an outer gearing through which it meshes with an intermediate spacer which is the part (5b), which part in turn meshes with an outer bushing which is the part (5c) that is flanged at the wheel (4).

Thus, the rotating axle body (1) drives the wheels (4) in rotation, for any relative axial position between the latter and the former. The two gearing pairs are curved cogs, to be able to absorb the possible misalignments between the axle body (1) and the axles of the wheels (4). As seen in Figure 1, the couplings (5) are assembled on the outer side of the wheels (4), identified as the grips side, leaving the central part of the axle body (1) free for assembling the demultiplier of the transmission (2) and the braking discs (3).

The fixing of the transverse position of each wheel (4) on the axle body (1) is established by means of mounting axial bearings (6), arranged on the outer part (5c) of the coupling (5). Each bearing (6) is housed in a locking bushing (7), which is a non-rotating piece. These bearings (6) support the wheel (4) - rail (15) transverse forces, these forces being finally absorbed in the support boxes (10).

Each locking bushing (7), as seen in Figure 9, determines respective symmetrical arm-like cantilever expansions (7a) escorting the axle body (1) in diametric opposite position. In the free end of each expansion (7a) is arranged a locking pin (11). In correspondence with the two locking pins (11) of each locking bushing (7), there are two pairs of sockets (16) solid with the end support box (10).

With the penetration of the two locking pins (11) of each locking bushing (7) into one or the other of the two pairs of sockets (16) of the end support box (10), the two possible transverse positions of each wheel (4) along the axle body (1) are fixed to be able to thus condition the distance between the wheels (4) to the two different track gauges.

As seen in Figures 3, 5 and 7, the locking pins (11) determine lower expansions (11a) establishing both a guiding action and stopping action in the transverse movements of the wheels (4) when the lower expansions (11a) are displaced along openings existing in the end support box (10).

In the ends of the rotary axle body (1) known as grips are assembled bearings (8) on which the support boxes (10) rest, transmitting the vertical load of the vehicle towards the track. These bearings (8) are axially immobilized with respect to the axle body (1) and on each of them is mounted a sleeve (9) which allows fixing the axle body (1) to the support box (10), maintaining the relative distance between both support boxes (10) and, therefore, between the two wheels (4), see Figures 1 and 2.

For fixing the axle body (1) to the support boxes (10), each sleeve (9) determines respective arms (9a) which, as seen in Figure 9, are extended symmetrically in diametric opposite position with respect to the axle body (1). In each of these arms (9a) is assembled a locking pin (12); such that, in correspondence with each locking pin (12), there is a socket (17) solid with the support box (10).

On the other hand, each end support box (10) comprises, as seen in Figure 1, a sheave (14) in correspondence with an additional rail (18), see Figure 2.

Figure 13 depicts the fixed installation on the ground, for changing the track gauge. This installation comprises: a downwardly inclined track sector (15a) with the current track gauge (15); the additional rail (18); two deflector guides (19) which are responsible for bringing each wheel (4) to its position for the new track gauge once they have been unlocked, and an upwardly inclined track sector (15b) with the new track gauge (15c).

The operation for changing track gauge is the following: the unit goes through the installation for changing track gauge at low speed driven by its own traction equipment. The wheels (4) move over the rolling rail (15) which starts a progressive downward inclination in the sector identified with the reference (15a); so that it will reach a time where the end support boxes (10) are supported throught the sheave (14), by the additional rail (18). When the end support boxes (10) are supported, the axle body (1) starts dropping until the separation existing between the support box (10) and the sleeve (9) is consumed, the axle body (1) thus being completely unloaded, at which time the rail of the downwardly inclined track (15a) disappears.

As the axle body (1) drops, the anchoring pins (11) come out of one of the two pairs of sockets (16) in the body of the support box (10); so that the wheels (4) are unlocked and, therefore, with freedom for transverse movement along the axle body (1).

With the wheels (4) unlocked, the deflector guides (19) bring the wheels (4) to their position for the new track gauge and, when the wheels (4) are duly positioned, the rail (15b) with the new track gauge and with an upwardly inclined ramp path appears, forcing the axle body (1) to rise vertically until reaching a point in which the locking pins (11) have already penetrated into the other pair of sockets (16), fixing the wheels (4) in this new position of track gauge, as seen in Figures 3, 5 and 7.

At that time, the wheels (4) are already supported by the rail (15c) with the new track gauge and the support of the sheave (14) on the additional rail (18) has ended, the automatic change of the track gauge being completed, at which time the load is again supported by the new track through the wheels (4).

It must be mentioned that, as seen in Figures 3, 5 and 7, the locking pins (12) have, on their lower part, a threaded shank (12b) with a bushing (12a); such that when the body of the axle (1) drops by gravity, it lowers the sleeve (9) with its arms (9a) and the set of locking pin (12), threaded shank (12b) and bushing (12a), with a guided movement with respect to the end support box (10), such that during the entire process of automatic change of track gauge, the position between the axle body (1) and the support boxes (10) is thus fixed and therefore the position of the support boxes to one another (10) is fixed.

Figures 3, 5 and 7 show how the sockets (16 and 17) are determined by bushing-like parts identified with the references (16a and 17a), respectively. The sockets (16) are closed top-wise by covers (22); so that between these covers (22) and each bushing (16a) extend springs (20). In the same manner, the sockets (17) are closed top-wise by covers (23), between which covers and the bushings (17a) extend springs identified with the reference (21), see Figure 9.

With this embodiment, both the bushings (16a) and (17a) are mounted according to a floating arrangement, which allows compensating different degrees of penetration of the pins (11 and 12) into said bushings (16a and 17a).

On the other hand, each end support box (10) incorporates, in its lower part, a safety latch. As seen in Figures 11 and 12, each safety latch is formed by a pivoting lever (24) provided with a skid (25) intended to slide, either on the additional rail (18) itself or on a rail attached thereto. Upon sliding the skid (25) a rotation of the lever (24) is established against the action of a torsion spring which maintains it in a stable position, in which a bolt (26) prevents the lowering movement of the bushing (9) with respect to the support box (10). The rotation of the lever (24) against the action of the torsion spring also causes the rotation of the bolt (26) which is thus brought to an unlocking position.

Thus, during the operation for changing track gauge, the bolt (26) is removed from its normal position by the change installation itself, upon sliding the skid (25) on the corresponding rail and it is brought to the unlocking position, thus only then allowing the drop of the axle body (1). Thus, the bolt (26) prevents the drop of the axle body (1) in driving conditions and in case a wheel accidentally loses all the vertical load of the vehicle gravitating thereon. A proximity sensor which will verify the opening and closing sequence of the bolt (26) has been foreseen for the purpose of ensuring that the throught the bolt (26) is adequately locked after its passage through the installation for changing the track gauge.