Tractor bogie with incorporated gauge-change system

Abstract: Tractor bogie with incorporated gauge-change system. It comprises two frames (2) which support sets of running gear (1,1') and carry sliding and centring blocks (3) to support the bogie and unweight the wheels as they pass through a gauge changer; a toothed extendible axle (4) arranged between each pair of sets of running gear (1,1'); and a pinion/ring-gear transmission set (14,15) fitted on the frame of the bogie to transmit the traction moment to the extendible axle (4). The invention is applicable to rolling stock adapted to run on two gauges.

Description: FIELD OF THE INVENTION The present invention relates to a tractor bogie which incorporates a gauge-change system, specifically the Talgo system. The bogie includes wheel sets which, as is customary in the Talgo gauge-change system, are each equipped with a wheel fixed by wedges to a short axle, in whose journals individual roller bearings are fixed by wedges and whose bearing-axle-boxes have, incorporated externally, lugs by means of which, interacting with the rods of point locking bars, these wheel sets are positioned on each of the two gauges. BACKGROUND OF THE INVENTION In patent ES-A-2,078,137, details are given of a system for locking the wheel sets of a bogie and of the system which allows translation of said sets when the wheels are unweighted as they pass through a gauge changer. However, said Spanish patent applies solely to the case of hauled bogies and does not cover a gauge change in connection with tractor bogies. In the case of axles far hauled stock, the wheels may be independent, which offers the fundamental advantage of the tendency of the wheel set to undergo a loop movement being eliminated, although, to prevent wear, it is necessary for the axles or the bogies where the latter are fitted to be equipped with the corresponding guiding system. With guiding, it is also possible to reduce and even eliminate the positive striking angle of the wheels when curves are taken. A guiding system of this type is described in patent ES-A-2,084,551. SUMMARY OF THE INVENTION On the basis of the Talgo gauge-change system, the invention has created a novel tractor bogie whose wheel sets may be displaced so that they can be adapted to the corresponding gauge. To this end, the bogie comprises two or more frames which each support two of said wheel sets and are joined to the actual frame of the bogie via elastic elements constituting the primary suspension of the bogie, each support frame of the wheel sets being equipped with sliding and centring blocks intended to support the bogie and unweight the wheels as they pass through the gauge changer. The support frames of the wheel sets guarantee the invariability of the gap between both wheels of the wheel sets and that the said wheels are parallel when they are positioned on each of the two gauges. For their part, the sliding and centring blocks guarantee transverse immobility of the frame on the gauge changer, which is necessary to achieve unlocking and subsequent locking of the locks of the wheel sets and also the correct translation of the latter. In order to achieve the characteristic inherent in a railway wheel set to automatically centre itself on the track, which considerably reduces wear of the flanges of its wheels and also improves its holding on the track, a grooved extendible axle has been incorporated between the wheel sets, allowing axial displacement of these sets with respect to one another but preventing relative rotation between the wheels, which also offers the advantage - in this case in which traction is also applied to the wheels - of said traction being applied to both wheels with the consequent advantage of fully exploiting the adhesion weight. According to one embodiment of the invention, the said grooved extendible axle consists of a joining piece at each end, secured to the extension of the journal of the respective wheel axle, which transmits the rotation of said journal to a protective tube and to an externally grooved tube secured to the previous tube. Between said joining piece and the protective tube, at each end of the extendible axle, there is a flexible disc which secures, in rotation, the wheel to said axle and also has the function of absorbing the small misalignments which may exist between the axles of both wheels, thereby acting as a universal joint. The extendible axle is supplemented with an internally grooved tube which prevents the relative rotation between said joining piece and said protective tube of both wheels, this internally grooved tube being the tube which ultimately makes both wheels secure in rotation. In a second alternative embodiment, the said grooved extendible axle also includes joining pieces and flexible discs identical to those of the first embodiment and there is also a protective tube secured to an externally grooved tube. In this second embodiment, a second internally grooved protective tube is also present. The difference between both embodiments lies in the fact that, in the first one, there are two externally grooved tubes secured to the protective tubes whilst, in the first one, use is made of a single externally grooved tube. In both embodiments, the frame of the bogie has pinion/ring-gear transmission sets fitted, one for each carrying frame of the wheel sets. In the first embodiment of the invention, the ring gear of each transmission set transmits the traction moment to the internally grooved tube via a hollow-axle transmission mechanism which will allow both pieces to be shifted off-centre with respect to each other, this shift originating from the deformation of the primary suspension. In the second embodiment of the invention, the ring gear of said transmission set transmits the traction moment to the internally grooved tube also via a hollow-axle mechanism. When the gap between the wheels varies, when this axle is displaced over a distance equal to half the difference between the gauges, the entire assembly of the pinion/ring-gear set will also be displaced even when said set could be positioned so that it is symmetrically off-centre on both gauges. Principal Claim 1 sets forth the essential characteristics of the invention whilst the subordinate claims contain improvements thereto. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more readily understood with the aid of the following description which refers to the attached drawings, in which: Figures 1 and 2 show an overall view of the first and second embodiments of the invention, respectively; Figures 3 and 4 illustrate the embodiment of Figure 1 in greater detail; and Figure 5 is a detailed view of the embodiment of Figure 2. DETAILED DESCRIPTION OF THE INVENTION As shown in Figures 1 and 2, two wheel sets 1 and 1' are integrated into a frame 2. For reasons of simplification, the drawings show a frame 2 of the type which is an underframe with cross members, but the requirements of the invention could also be fulfilled by integrating the wheel sets into a bracing system which is different from the frame 2 illustrated. The bogie illustrated incorporates two frames 2, each of which is joined to the actual frame of the bogie via elastic elements constituting the primary suspension of the bogie. In addition, each of said frames 2 is equipped with sliding and centring blocks 3 designed to allow unweighting of the wheels as they pass through a gauge changer, this situation being necessary to allow translation of the wheels from one gauge to the other. To prevent relative rotation between the wheels of both wheel sets 1, 1' of each frame (2), a grooved extendible axle system 4 is incorporated between said sets. According to Figures 3 and 4, said axle 4 consists, at each end, of a joining piece 5 which is secured to the extension of the journal of the respective wheel axle and which transmits the rotation of said journal to a protective tube 6 and to an externally grooved tube 7 secured to the tube 6. Between each joining piece 5 and the corresponding protective tube 6 there is a flexible disc 8 which secures, in rotation, the wheel to the extendible axle 4 and which also has the function of absorbing the small misalignments which may exist between the axles of both wheels, said disc 8 thereby acting as a universal joint. The grooved extendible axle 4 also includes an internally grooved tube 10 which prevents the relative rotation between the joining piece 5 and the protective tube 6 of both wheels. Therefore it is the tube 10 which ultimately makes both wheels secure in rotation. According to Figure 5, the grooved extendible axle 4 includes, at each end, a joining piece 5 which is identical to that illustrated in Figures 3 and 4, as well as a flexible disc 8 which is also identical to the discs 8 of Figures 3 and 4. In Figure 5, in addition to a protective tube 11 secured to an externally grooved tube 12, it is possible to see a second protective tube 11' which has grooving on its inside. An internally grooved tube 13 is interposed between both tubes 11, 11'. As may be observed, in Figure 5 there is a single externally grooved tube 12, whilst in Figures 3 and 4 use is made of two externally grooved tubes 7. The extendible axle system 4 incorporates a pinion/ring-gear transmission set 14, 15 which enables a variable-width railway axle to be additionally converted to a tractor axle. This set is fitted on the frame of the bogie. As may be observed in Figure 3, the ring gear 15 transmits the traction moment to the internally grooved tube 10 via a hollow-axle transmission mechanism which will allow both pieces to be shifted off-centre with respect to each other, this shift originating from the deformation of the primary suspension. Moreover, as may be seen in Figure 5, the ring gear 15 transmits the traction moment to the internally grooved tube 13 also via a hollow-axle mechanism. When, in this case, the gap between the wheels varies, when the extendible axle 4 is displaced over a distance equal to half the difference between the gauges, the entire assembly of the pinion/ring-gear set 14, 15 will also be displaced, although said set could be positioned so that it is symmetrically off-centre on both gauges. As a consequence of the development of the invention, it will now be possible for the gauge change to affect not only the hauled rolling stock but also the tractor or locomotive front sections. This will avoid having to have recourse to external locomotives to push and/or haul a train whilst gauge-change operations are being carried out. Although the above description referred to two-axle bogies, the invention could obviously be applied also to tractor stock with bogies with more than two axles. For this reason, the scope of the invention is claimed to be limited solely by the content of the attached claims.

Claims: Tractor bogie with a main frame and with incorporated gauge-change system which includes wheel sets (1,1') each consisting of a wheel fixed by wedges to a short axle, whose journals carry individual roller bearings and whose bearing-axle-boxes incorporate on their outside lugs which, interacting with rods of point locking bars, position each wheel set (1, 1') on each of two gauges, characterized in that it comprises frames (2) which each support two of said wheel sets (1,1') and are joined to the main frame of the bogie via elastic elements constituting the primary suspension of the bogie, each frame (2) being equipped with sliding and centring blocks (3) intended to support the bogie and unweight the wheels as they pass through a gauge changer, whereby in each frame (2) a grooved extendible axle (4) is arranged between both wheel sets (1,1') of said frame and consists of two end joining pieces (5) secured to the extension of the journal of the respective wheel axles, two protective tubes (6;11,11') to which the rotation of the journal of the axles of the wheels is transmitted via said end joining pieces (5), at least one externally grooved tube (7;12) secured to said protective tubes (6;11,11'), two flexible end discs (8) which are each fitted between an end joining piece (5) and the corresponding protective tube (6;11,11') and which secure, in rotation, the wheels to the extendible axle (4), and an internally grooved tube (10;13) which prevents the relative rotation of the joining pieces (5) and the protective tubes (6;11,11') of both wheels of said wheel sets (1,1'); and, whereby for each frame (2), a pinion/ring-gear transmission set (14,15) is fitted on the frame of the bogie to transmit the traction moment to the internally grooved tube (10;13) via a hollow-axle transmission mechanism. Tractor bogie according to Claim 1, characterized in that it incorporates two frames (2). Tractor bogie according to Claim 2, characterized in that each frame (2) has a configuration in the form of an underframe with cross members. Tractor bogie according to any one of Claims 1 to 3, characterized in that the extendible axle (4) incorporates two externally grooved tubes (7). Tractor bogie according to any one of Claims 1 to 3, characterized in that the extendible axle (4) incorporates a single externally grooved tube (12) and the tube (11') has internal grooving.

Inventors: FERNANDEZ BENITEZ MANUEL, GARVIA HIERRO ANTONIO, LOPEZ GOMEZ JOSE LUIS, FERNANDEZ BENITEZ, MANUEL, GARVIA HIERRO, ANTONIO, LOPEZ GOMEZ, JOSE LUIS, Lopez Gomez, José Luis 
Applicants: TALGO PATENTES, PATENTES TALGO, S.A.
Application year: 1997
Main classification: B61F7
IPC codes: B61C9, B61F7