Steering bogie for railway cars

Abstract

 Steering bogie for railway cars in which the axle-­wheels units (12) connected with the bogie by means of primary suspensions (14), are shifted in such a way as to form with their axes angles different from 90° to the longitudinal axis of the bogie when it runs along a track bend.

Description

[0001] The present invention relates to a steering bogie for railway cars.

[0002] Steering railway car bogies are known, which are equipped with complex lever systems, which lever systems are generally fastened either to the axle boxes or to the axles, and result to be cumbersome inside the interior or the bogie. 0wing to their great complexity, this type of steering bogies require a lot of servicing and in the overall are subject to high wear rates, which jeopardize very soon the efficiency of the system.

[0003] The purpose of the present invention is of obviating the drawbacks which affect said prior art.

[0004] In view of such a purpose, a steering bogie for railway cars is provided, which is constituted by a chassis defining a longitudinal axis thereof, and equipped with at least two axle-wheels units defining a longitudinal axis of their own, each one of said axle-­wheels units being provided with two axle boxes, each one of said axle-wheels units being connected with said chassis of said bogie by means of primary suspensions positioned laterally to said axle boxes, said longitudinal axis of said railway car bogie being in an orthogonal position relatively to said longitudinal axes of said axle-wheels units under resting operating conditions or when the railway car runs along a straight track portion, characterized in that between said chassis of the bogie and each axle box of said axle-wheels units a jack is interposed, which is capable of generating a plurality of forces concurring to position said longitudinal axes of said axle-wheels units in an angular position different from said orthogonal position.

[0005] Characteristics and further advantages of the present invention will be clearer from the following disclosure as referred to the hereto attached drawing tables in which:

Figure 1 shows a side view of a bogie according to the present invention;

Figures 2 and 3 show schematic plan views of two different operating positions of a bogie according to Figure 1.

[0006] Referring to the figures, a bogie according to the present invention is generally indicated by the reference numeral 10. Such a bogie 10 is essentially constituted by a chassis 11 onto which two axle-wheels units 12 are fastened by means of axle boxes 13 connected with primary suspensions 14. In their turn, the primary suspensions 14 are connected with the chassis 11 of the bogie. Furthermore, for each axle box 13 a jack 15 is provided, which is fastened to the chassis 11 at a higher level than the level at which the axle box 13 is fastened.

[0007] The jacks 15 are furthermore connected with a control system, which is schematically indicated by the reference numeral 16 in Figures 2 and 3.

[0008] The primary suspensions of this type of bogies preferably are large-rubber-volume suspensions, or rolling-rubber-ring suspensions, or steel spring suspensions, with helical springs of cylindrical or conical shape.

[0009] For the sake of a better interpretation of the figures, of the text and of the appended claims, a longitudinal axis of the bogie 10, indicated by the reference numeral 20, and longitudinal axes of the axle-­wheels units, indicated by the reference numeral 21, are schematically shown in the figures.

[0010] During the normal traveling along a straight track portion, the bogie 10 will be in the schematic configuration shown in Figure 2. Figure 3 shows the configuration assumed by the bogie 10 while traveling along a track bend.

[0011] In the hypothesis of Figure 3, the jacks 15 of the internal side of the bend are retracted, and the jacks of the external side of the bend are in their extended position. In this way, the axle boxes 13 compress the elastic element of the suspensions which, as said, can be rubber, or can be a steel spring, thus enabling the axle-­wheels units 12 to modify the position of their axis 21 relatively to the axis 20 of the bogie.

[0012] In Figure 3 the angle α is visible, by which the axles 21 have been shifted relatively to their initial position, as shown in simple dashed line.

[0013] The axles 21, from their position perpendicular to the axis 20 will therefore come to coincide with the radius of curvature of the bend along which the bogie runs.

[0014] Another advantage of the present invention is that the jacks 15, by being in an oblique position, generate a vertical force component directed downwards, which considerably contributes to increase the stability of the railway car when traveling along bends, by favouring the adherence of the bogie to the track. Furthermore, it is forecast that a type of bogie like the one herein diclosed can be used both for railway cars or vehicles of the variable-trim type, and of conventional type.

[0015] The present invention is disclosed herein for merely illustrative, non-limitative purposes, and it should be intended that modifications and changes may be supplied by those skilled in the art without departing from the scope of protection of the present exclusive privilege.

Claims

1. Steering bogie for railway cars, constituted by a chassis defining a longitudinal axis thereof, and equipped with at least two axle-wheels units defining a longitudinal axis of their own, each one of said axle-­wheels units being provided with two axle boxes, each one of said axle-wheels units being connected with said chassis of the bogie by means of primary suspensions positioned laterally to said axle boxes, said longitudinal axis of said railway car bogie being in an orthogonal position relatively to said longitudinal axes of said axle-wheels units under resting operating conditions or when the railway car runs along a straight track portion, caracterized in that between said chassis of the bogie and each axle box of said axle-wheels units a jack is interposed, which is capable of generating a plurality of forces concurring to position said longitudinal axes of said axle-wheels units in an angular position different from said orthogonal position.

2. Steering bogie for railway cars according to claim 1, characterized in that said jack is fastened to said chassis at a level higher than the level at which the axle box is fastened, so as to result inclined.

3. Steering bogie for railway cars according to claim 1, characterized in that said jacks are simultaneously actuated by a control system.

4. Steering bogie for railway cars according to claim 1, characterized in that the jacks positioned on a same side of said chassis act in agreement either performing a thrust action, or performing a traction action.

5. Steering bogie for railway cars according to claim 1, characterized in that said jacks cause steering forces, and forces stabilizing the motion of said bogie along bent track portions.

Drawing