BOGIE CONSTRUCTION FOR A RAILWAY CAR

Abstract: A bogie for a railway vehicle comprising of at least two articulated, pivotable and rotatable wheel body parts (2, 3) including wheels or a set of wheels (4, 5) mounted in bearings and the supporting body (6) of the bogie being connected to the parts by a suspension (9a, 9b) of the railway vehicle. In the bogie, two wheel body parts (2, 3) have been resiliently interconnected from their side con­ structions by two stabilizer constructions (16) both of which have been articulated to the supporting body (6).

Description: The invention relates to a bogie for a railway vehicle comprising at least two with a coupling joint interconnected pivotable and rotatable parts of the wheel body each with wheels or a set of wheels mounted in bearings and with the supporting body of the bogie being connected to them by spring suspension of the railway vehicle. Bogie constructions currently used in railway vehicles such as engines and cars or other similar vehicles are usually such that the body construction of the bogie is stiff and that the wheel sets have been suspended to it. A stiff bogie body includes many drawbacks, one of the most essential of which shows up when moving through curves. The bogie body being stiff, the wheel sets of the bogie are not able to move radially in the curve, but the wheels of the set wedge against the rails which brings about extreme wearing of the wheels and rails. Such a wedging makes e.g. a part of the engine's pull force to "vanish" in the curve resistance. Riding through curves with such a railway vehicle with a stiff body is possible only by using an axial clearance between the bearing housing and the bogie body (construction type Y25). When driving straight, this kind of bogie construction behaves well but in curves it will "push" as described above. The construction can be modified by making the wheel sets clearly self-steering with each axle adapting to the direction of the rails regardless of the other axles (construction 65sd). Said, construction functions well with small speeds both in curves and when riding straight but when the speed increases, a vibration, so called hunting will occur around the vertical line against the centre line of the axle. This makes the use of such bogies unstable and even dangerous when riding with high speeds. Various solutions have been tried in order to avoid the drawbacks described above. For example, in the publications FR-A-76296, US-A-4 478 153, EP-A-165752, EP-A-161729 and US-3 528 374, different bogie constructions have been described where the bogie body has been divided into two parts and articulated in the middle so that the wheel sets are able to rotate with respect to each other and thus follow the curves according to the curve radius, i.e. radially. Typical to all radially controlled bogie constructions is that they are explicitly steered on the basis of the curve radius when the steering is based e.g. on the mechanical observation of the angle difference between the bogie and the car body and on the conversion of the angle difference to an angle difference of the two bogie parts equivalent to the curve radius. Generally it is a question of a mathematical problem of changing a known quantity into another prescribed quantity. Only the mechanisms, with which this is carried out in the said publications, differ from each other. These constructions have a drawback of making the constructions complicated, expensive and heavy, as can be seen in the said publications. E.g. in the publication FR-A-76296 a rod connecting the bogies prevents the efficient use of the space between the bogies for loading. When using a fluid coupling of the publication US-3 528 374 between the bogies, the said space can be exploited but the construction will be expensive to service and it will damage easily. When using e.g. the construction of US-A-4 478 153 or GB-A-316 317 where the sets of wheels are not mechanically controlled, but they are allowed to be steered by elastic elements in the vicinity of sides of the wheel body parts of the bogie, the characteristics lie somewhere between the mechanically controlled bogies and freely controlled sets of wheels. By extending the axial distance of the bogie, a better riding stability can be achieved, but the bigger bogie size will take otherwise usable space between bogies. If e.g. the loading space of a freight car is wanted to make as big as possible, the bogies must be built as short as possible which means that the riding characteristics will get worse or that the steering of the bogie parts will be more complicated. When it is wanted to maximize the transport space, also the supporting constructions of the car must be made as small as possible, which would require e.g. extending the side frames to the point of the bogie. This again means that, deviating from the traditional way, the bearing and cushioning of the bogies must be made inside the wheels. Even if the side frames were not drawn to the sides of the bogie, in question of articulated two-part bogies, at least the cushioning must be placed inside the wheels because loading through the springs must be brought in vertical plane through the axial line of the wheels in order to avoid moment in the bogie joint or to avoid an extremely complicated construction. As a result of this, the car itself will lean considerably in the curves because also the bearing distance of the springs will narrow in the lateral direction of the car. The above-mentioned problems will still become emphasized in situations occurring frequently in railways, i.e. in situations where, becuase of the roughness of the railway e.g. one of the bogie wheels rises higher or falls lower than the other wheels; this can happen e.g. on railway yards at gearings or when approaching a curve (when the outer rail of the curve will rise with respect to the other) or when leaving a curve (when the outer rail will fall with respect to the other rail). The two parts of the bogie will then twine with respect to each other about the longitudinal axis of the car. Adding to this the turning by the curve and the tendency to incline caused by the centrifugal force, it must be stated that no known solution provides a satisfactory riding result. It can of course be imagined that the technical knowledge of the various publications, e.g. the inclination suppressor of DE-A-2 422 825, be connected to the said bogie constructions. In principle, it should then be possible to achieve a functional construction, but it would be so complicated, heavy, demanding a lot of service and expensive that it would not be realistic. The object of the invention is thus to provide a bogie for a railway vehicle comprising radially controlled interconnected sets of wheels, i.e. the wheel sets being self-steerable and not mechanically controlled and which will be suited for fast speeds without inconvenient phenomena. The object of the invention is further to provide a bogie construction where the part supporting the car body is cushioned with respect to the bogie body and which is movable to the bogie body also in horizontal directions but with which the inclination of the car body by lateral acceleration or eccentric load can be limited as small as necessary in each case. The object of the invention is in particular to provide a bogie construction where the inclination forces are divided equally on successive bogie wheels regardless of the fact whether all the wheels are at the same level or if all of them are situated in different heights. The object of the invention is further to provide a construction where aot. the brake gears and other similar controlling elements are right off mountable in such a way that they stay stable with respect to the wheels irrespective of the riding situation. Another object of the invention is also to provide a bogie construction with which it is possible to carry out the above-mentioned objectives with a simple, reliable and cost-effective construction. With the bogie construction according to the invention, it is possible to achieve a crucial improvement in the above-mentioned drawbacks and to realize the objectives described above. In order to achieve this, the device of the invention is characterized with the distinctive features of claim 1. The most important advantage of the invention can be seen in that it is possible to provide a bogie construction operating well even in fast speeds without the difficulties of curve drive of a stiff bogie and without the complicated construction of a mechanically controlled bogie. An advantageous feature is also that it enables the use of a bogie with a small axle distance and an inner body bearing and cushioning at the same time as the car inclination is made as small as desired and the wheel loads can be kept even. Another advantage of the invention is that the bogie construction can be made small in size, light, constructionally simple and reliable and that the useful capacity of the car can be extended due to the decrease in the bogie size and to the side construction possibly of another kind. The invention will next be described in more detail referring to enclosed drawings where Fig. 1 is a perspective diagrammatical side-view of a bogie construction according to the invention; Fig. 2 is a diagrammatical perspective view of the construction of Fig. 1 seen from above; Fig 3. shows the construction of the Fig. 2 from the same direction but partly opened; Fig. 4 shows an application of the stabilizer construction of the invention in more detail and partially in section and in side view; Fig. 5 shows another application of the stabilizer construction of the invention in diagrammatical side view; and Fig. 6 shows still another application of the stabilizer construction of the invention in diagrammatical side view. Fig. 1 shows in general view the bogie 1 of the invention comprising two wheel body members 2 and 3 both equipped with a set of wheels 4 and 5. Supporting body 6 comprises a cross member 7 and side frames 8a and 8b. The side frames 8 and the cross member 7 are stiffly connected to each other and rest on springs or spring bulks 9a, 9b on the wheel bodies 2 and 3 so that the load force of the car is directed through the springs to the members of the wheel body at least approximately in vertical plane through the axle line of the sets of wheels allowing thus the movement of the wheel body in horizontal plane with respect to the springs. The car body, which is not shown in the figures, is connected to the bogie centre 10 on the cross member 7, the centre being of a standard type construction. When the car inclines, it meets the side supports 11a, 11b. Figure 3 shows the wheel bodies 2 and 3 both of which are formed mainly e.g. by a horizontal U-form body element with side members 14a, 14b and 15a, 15b, respectively, and a lateral base member 12a and 12b, respectively. The body elements have been interconnected by a link 13 from their base members 12a and 12b through the middle line of the car. The said connecting link 13 has been constructed so that it lets the wheel body members 2 and 3 turn with respect to each other both horizontally and vertically; further, it allows the rotation of the wheel body parts 2 and 3 with respect to each other about the longitudinal axis of the car. Such link constructions are numerous, and they can also consist of links and bars; some of these constructions have been described in the said reference publications so here they will not be explained in more detail. The wheel sets 4 and 5 or respectively the wheels have been stiffly mounted in bearings to the branches 14a, 14b, 15a, 15b of each of the U-form body bars so that the rolling direction will follow the direction of the branches. Thus the wheel body parts 2 and 3 form a bogie construction with connected, radially controlled wheel sets. According to the invention the wheel body parts 2 and 3 have been connected in the vicinity of the other side pair 14a, 15a of the U-form body elements and in the vicinity of the other side pair 14b, 15b resiliently with each other by two essentially similar stabilizer constructions which have generally been described with the reference number 16. The said two stabilizer constructions 16 have further been articulated to the side frames 8a and 8b of the supporting body 6. Each of the stabilizer constructions has been constructed so that, examining the movement of the wheel set parts 2 and 3 with respect to each other, it enables the movement of said side edges 14a and 15a or 14b, 15b respectively at least somewhat with respect to each other both vertically and in the direction of motion of the bogie. Each of the stabilizer constructions has been articulated to the side frames 8a, 8b of the supporting body 6 so that the supporting body 6 and the wheel body 2, 3 can move laterally with respect to each other. The said construction combination enables the connecting link 13 to be sensitive and without stiffening constructions. The construction operates in the following way: When a railway vehicle drives to a curve, the centrifugal force tends to turn the car body about the bogie centre 10, when the car body supports against the side support 11a or 11b. Without any stabilizer construction, the spring on the outer side of the curve would then sink and the spring on the inner side of the curve would rise, thus causing the inclination of the car body towards the outer edge of the curve. However, the stabilizer construction according to the invention prevents this by transferring e.g. the force applied downwards to the side frame from the support 11a or 11b from the side frame 8a or 8b equally to the wheel members 2 and 3 through the stabilizer construction and through the said base members 12a and 12b into the width of the body element. Because the base members 12a and 12b are, due to the stabilizer constructions 16, stiff with respect to the cross-directional moment and because of the stiffly fastened construction the support body side on the side of the outer curve is not able to sink nor can the support body side on the side of the inner curve rise, t.e. the stabilizer constructions 16 build a suppressor for the inclination. Because the wheel body parts 2 and 3 are able to turn horizontally with respect to each other, the said radial self-steerability of the wheel set can be maintained. Because the wheel set parts 2 and 3 can turn with respect to each other about the horizontal axis via the connecting joint 13, a flexible movement being independent of the inclination or its suppression is possible when the side pair 14a, 15a and 14b and 15b, respectively, always yields the same amount because of the stabilizer constructions 16. Because the connecting joint 13 allows the wheel body parts 2 and 3 to twist longitudinally with respect to each other, which also the stabilizer constructions 16 allow because of their elasticity and links, the wheel sets 4 and 5 can adjust to the roughness and winding of the rails. By providing the stabilizer construction 16 with proper resilience or other suppression, it is possible to control the steerability, and the operation of the bogie can be made in a desired way, i.e. fulfilling all the demands in practice. Because it is thus possible to control the inclination and motion precisely in the desired way, dimensions of the bogie can be reduced, and the springs and bearings can be placed inside the wheels which makes the whole bogie construction small and the space thus saved can be utilized in the car body. As an additional advantage e.g. the brake mechanisms can be fastened to the wheel body parts so that they keep their exact position with respect to the wheels irrespective of the riding conditions. As a summary of the operation of the stabilizer constructions 15 it can still be said that they lead to the equal division of the loading caused by the weight of the car body on both parts 2, 3 of the bogie body; also the centrifugal force caused by the curve is divided equally on two successive wheels in the bogie thus preventing the inclination of the car body. The above-mentioned characteristics stay the same irrespective of the roughness of the railway i.e. irrespective of the fact whether the wheel body parts 2 and 3 are twisted with respect to each other or not. One construction of the stabilizer 16 of the invention is next described in more detail. The stabilizer construction has been presented in more detail in figure 4 and it corresponds to the stabilizer construction which has been presented diagrammatically in the figures 1 - 3. As described above, each bogie includes two stabilizer constructions 16, one on each side of the bogie. In this form of realization, the stabilizer construction 16 is principally formed by a vertical reaction bar 17 which has been fastened with a link 18 to the outer edge or lower part of the longitudinal beams 8a or 8b of the support body. One end of the reaction bar 17 is in this case connected with another link 19 mainly to a horizontal, rod-like or sheet-like compensator 20, more exactly in the middle of the compensator. The compensator 20 extends on both sides of the wheel bodies inside or by the branches 14a and 15a and 14b and 15b, respectively, so that the bar 17 is situated in the middle of these and longitudinally approximately in the middle of a gap 23 when the wheel sets are at rest and parallel. Elastic constructions 25a, 25b formed by two spring units 21a, 21b have been placed inside the side members 14a, 15a, 14b, 15b or to a respective point so that the compensator 20 extends between the spring units 21a, 21b and is pressed by them. The spring units 21a, 21b have been fixedly mounted by elements 22 to the said side member of the wheel body. Side members 14a, 15a, 14b, 15b of the wheel bodies comprise holes 31 or similar members opening towards the gap 23 between the wheel bodies 2 and 3 with the said spring units 21a, 21b being placed to said gaps so that they press the compensator 20 between them approximately in longitudinal direction of the reaction bar 17. This enables the movement of the compensator 20 in all horizontal directions VT by sliding between the faces 24a, 24b of the units pointing towards each other, and makes it thus possible for the compensator to incline around the apparent pivoted axles lying in the same horizontal plane. Thus the wheel body sides 14a and 15a and 14b and 15b, respectively, can draw away from and approach each other and move a litte with respect to each other up or down when the force extends from the parts of the wheel body as the bogie is steered according to the railway. The links 18 and 19 are responsible for maintaining the connection transmitting force on the reaction bar 17 to the longitudinal beams 8a and 8b which are stable with respect to the wheel body sides, whereas forces from the reaction bar 17, i.e. load and inclination forces are divided by the compensator 20 equally to both parts 2, 3 of the wheel body. So the stabilizer construction transmits the forces from different directions forward in different ways. Figure 5 shows diagrammatically another application of the stabilizer construction where the same reference numbers indicate the same parts as above. In this application, the longitudinal beam 8a and 8b has been connected by a link 18 approximately to the middle of the reaction bar 26, and the ends of the bar 26 have been connected to the side members 14a, 15a and 14b, 15b of the wheel body by elastic constructions 25a, 25b. The elastic construction 25a, 25b is here formed by a link 27 fastened to the reaction bar 26 by an arm 28 extending to the bar 26 in an angle, advantageously approximately in right angle, and by links 29 connecting the arm 28 and the side members 14a, 15a, 14b and 15b. Also this construction makes the same motions and operations possible as the stabilizer construction of figure 4. Figure 6 presents a modification of the application of figure 4 the same reference numbers indicating similar parts. In the application of figure 6, the links 18 and 19, the reaction bar 17 and the stabilizer 20 correspond with the parts of figure 4. Elastic constructions 25a, 25b have here been changed to a construction where the compensator 20 projects e.g. inside the side members 14a, 15a, 14b and 15b and where the compensator end comprises a link construction allowing the turning to all directions such as a ball joint 30. As the ball joint has further been arranged horizontally slidably with respect to the side members 14a, 14b, 15a, 15b, it is possible to provide the same operations as with the constructions of figures 4 and 5. The difference between the application of figure 4 and those of figures 5 and 6 is that the latter ones act as inclination stabilizers completely stiffly, i.e. they do not allow any kind of inclination caused by the centrifugal force. The application of figure 4, on the other hand, allows a small inclination because the respective lower spring units 21b of the elastic constructions 25a and 25b in the adjacent side elements can simultaneously press together due to the force which is equally divided by the compensator at the same time as the upper spring elements 21a get longer or vice versa. It is obvious that the elements enabling the resilience corresponding to the construction of figure 4 can easily be connected to the construction principles of figures 5 and 6; these elements, which are not described more closely, can be fastened either to the links 27, 29, 30 or to the arms 28. Also the supporting link 18 and the connecting link 19 of the compensator can be suspended as well as the reaction bar 17, 26 and the compensator 20. Also other suppressive elements can be used. The link 19 is not necessary for the operation of the device, but it can be replaced by either a stiff connection, i.e. the reaction bar 17 and the compensator 20 can be made of one piece which, however, results in considerably increased forces leading to a too heavy and otherwise unadvantageous consctruction. Also other combinations of rods and links besides the one being described can be developed. It is essential that they can bring about the operations mentioned in the claims. Breaking devices are fastened to the wheel body 2, 3, and a limiter construction between the wheel body parts 12a, 12 b the cross beam 7 transferring the decleration forces from the supporting body to the wheel body. These constructions have not been described in the figures.

Claims: A bogie for a railway vehicle comprising at least two articulated, pivotable and rotatable wheel body part (2,3) of the bogie, wheels or a set of wheels (4,5) being mounted in bearings to the both of these supporting body (6) of the bogie being connected to these by suspension (9,9a) of the railway vehicle and the said two parts (2,3) of the wheel body being resiliently interconnected from their side constructions (14a,15a; 14b,15b) or in their vicinity characterised in that said interconnection is provided by two corresponding stabilizer constructions (16) both of which have been articulated to the supportin body (6) and that the stabilizer construction is formed by a reaction bar (17;27) fastened to the side elements (8a;8b) of the supporting body (6) by a supporting link (18); the said reaction bar is connected to both side constructions (14a and 15a; 14b and 15b) of the wheel body parts by elastic constructions (15a,25b) enabling the movement of the reaction bar (17;26) or its extension at least in all horizontal (VT) directions and the twisting with respect to all side elements (14a,14b,15a,15b). A bogie according to claim 1, characterised in that the suspensions (9a,9b) of the railway vehicle are supported to the wheels body parts (2,3) in vertical plane or in the vivinity through the axle lines so that the two parts of the wheel body pivot with respect to each other by one (13) or more connecting links. A bogie according to claim 2, characterised in that the elastic construction (25a, 25b) are built by two spring units (21a,21b) fixedly situated in the side constructions (14a,15a,14b,15b), and that the compensator (20) being placed approximately perpendicularly against the reaction bar (17) and fastened to it has a part of its area pressed between the spring units (21a, 21b). A bogie according to claim 2, characterized in that each of the elastic consctructions (25a, 25b) is formed by a ball joint (30) or a similar element with a compensator (20) being connected to the reaction bar (17) with respect to which it lies approximately perpendicularly, and that each of the links (30) or similar elements has been arranged so that they slide approximately horizontally in each of the side constructions (14a, 14b, 15a, 15b). A bogie according to claims 3 or 4, characterized in that the reaction bar (17) has been connected to the compensator (20) by a link (19). A bogie according to claims 4 or 5, characterized in that the ball joints (30) or similar elements have been arranged resiliently and principally vertically with respect to the side constructions (14a, 14b, 15a, 15b), and that means to suppress the horizontal movement have been arranged to the connection of the ball joint (30) or similar elements. A bogie according to one of the claims 3 - 6, characterized in that the spring units (21a, 21b) and/or other similar suspensions have been produced by using rubber springs. A bogie according to claim 2, characterized in that the elastic constructions (25a, 25b) consist of an arm (28) the other end of which has been fastened to the end of the reaction bar (17) by a link (27), the other end being connected to one of the side constructions (14a, 14b, 15a, 15b), and that the joint of the reaction bar (17) to the supporting link (18) has been made essentially in the middle of the reaction bar (17). A bogie according to claim 8, characterized in that elastic elements have been arranged to the connecting links (27, 29) of the arm (28) or to the arm itself. A bogie according to one of the claims 2 - 9, characterized in that the supporting link (18) and/or the connecting link (19) of the compensator is an elastic link and/or a reaction bar (17) and/or that elastic elements and/or suppressive elements have been arranged to the compensator (20).

Inventors: KAHRA, OSSI, KAUHANEN, AKI, KEMPPAINEN, MARKKU
Applicants: RAUTARUUKKI OY
Application year: 1990
Main classification: B61F5
IPC codes: B61F5