Description The invention relates to a railway bogie assembly comprising at least two suspensions on an axlebox and having an adapter being required for mounting the said suspension to a bogie frame.

Railway bogie assembly generally comprises:

- a wheelset comprising a rotatable axle, wheels mounted on the axle and at least one axlebox wherein at least one rolling bearing is mounted for supporting the rotatable axle ;

at least one suspension mounted on an axlebox link arm, the said suspensions being of any type such that helical springs from UIC standards or hydraulic suspensions such that disclosed in US2002-0089102;

a bogie frame; and

an adapter able to make the wheelset supporting the said bogie frame.

Adapters are basically welded to the lower surface of the bogie frame and fixed via assembling means to the axlebox. In case of freight rail vehicles, the adapter can be directly fast with the axlebox suspensions.

However, the standard adapters currently in the market are not designed for improving the railway bogie performances and manufacturing process.

Indeed, they are usually full metal cast parts or welded metal part but without any weight optimization. Weight reduction is a constant worry of optimization in trains and freight rail vehicles for consuming less energy for a given overall load or for having an increased load for a given energy consumption. Moreover, the manufacturing process of the complete railway bogie is not optimised for easier and more efficient steps in particular the mounting process of the bogie frame on the wheelset

One object of the present invention is to overcome these drawbacks by providing a railway bogie assembly comprising at least one axlebox with at least one suspension, so that the railway bogie has an improved adapter for facilitating the mounting process and having reduced weight.

According to the invention, such an adapter is characterized in that it comprises at least one bracket fast with the bogie frame and mounted upon the at least one suspension, the said at least one bracket comprising an opening on its upper surface wherein assembling means can fit.

An assembling plate is fast with the bottom surface of the said at least one bracket. This assembling plate is dedicated to be mounted on an assembling surface defined on the top of the suspension. The assembling plate also comprises an assembling opening in which assembling means can engage. It permits the assembly of the adapter fast with the bogie frame to the at least one axlebox. The assembling means can be on any type such that bolts, rivets, mounting lugs or others without being a limitation for the present invention.

The at least one bracket comprises a surrounding wall which defines an inner empty volume between the assembling plate on the underside and the bogie frame on the top.

The inner empty volume of the bracket is defined by the bracket walls, the assembling plate on the underside and the bogie frame on the top. The assembling means fits in this inner empty volume. According to further aspects of the invention, which are advantageous but not compulsory, such an adapter may incorporate one or several of the following features as long there is no contradiction:

The at least one bracket is placed under an inclined section of the bogie frame.

- The at least one bracket is covered by a metal plate. The upper opening is provided through this metal plate and the upper part of assembling means fits in the thickness of this metal plate.

- The adapter fast with the bogie frame cooperates with an adapter fast with the suspension in order to have the wheelset able to support the bogie frame.

- The at least one axlebox comprises at least two suspensions.

The adapter comprises a first bracket and a second bracket at each end. The said first and second brackets are linked together by an elongated part. Any additional bracket is optionally placed between the said first and second brackets and fast with the elongated part. These additional brackets can be of any type (cylindrical or other) without being a limitation for the invention. Such an elongated part permits a facilitated assembling and a better adjustment of the adapter positioning on the bogie frame compared to the use of separated and distinct brackets. Moreover, the elongated part enables a better distribution of forces and avoids having too important stress on the brackets alone .

- The first bracket is positioned under a horizontal section of the frame bogie. It comprises a lateral wall such that it is perpendicular to the bogie frame section on which the adapter is fast, and has a U-shape on cross-section defined with a horizontal plane .

- The first bracket comprises at least one side wall fast with the lateral wall . The said side wall forms an obtuse angle β with an upper surface Si and an acute angle a with a lower surface S ₂ .The side wall may be a plane surface or a curved shape surface.

- The first bracket comprises a lateral wall with a U-shape and a recess.

- The second bracket is positioned under an inclined section of the frame bogie.

- The second bracket is covered by an inclined end of the elongated part. The upper opening is provided through this inclined end and the upper part of assembling means fits in the thickness of the elongated part.

The second bracket is such that the elongated part is directly attached to the surrounding wall, forming a wide upper opening on the upper inclined surface of the said bracket.

- The at least one bracket comprises lateral and side walls having a thickness comprised between 10 and 20 mm.

Brackets are rigidly maintained to the elongated part and/or the bogie frame by rigidity means.

- All the parts of the adapter are welded together.

- The complete adapter is molded.

- The adapter is directly welded to the bogie frame or is welded to the bogie frame via the elongated part.

The advantage of such a bracket design compared to a standard cylindrical bracket is that the necessary available space is optimized. Indeed, the upper part of the assembling means is as close as possible of the bogie frame, eventually in the elongated part thickness and/or metal plate. Then it requires less material and enables a weight reduction, but without decreasing the bracket rigidity .

Moreover, the upper opening of the at least one bracket allows a passage for eventually the insertion of assembling means and/or tools by an operator during manufacturing. According to another aspect of the invention, a railway coach is mounted upon the railway bogie and directly supported by the bogie frame for permitting the railway coach displacement on rail tracks. Moreover, one can mount two railway bogies at each end of the railway coach for supporting it.

Further advantages, features and details of the invention will be described with reference to the appended and non-limiting drawings wherein:

- Figure 1 is a side view of the railway bogie;

Figure 2 is a perspective view of the left part of the railway bogie assembly according to the first embodiment;

Figure 3 is a longitudinal cross section of the adapter according to the first embodiment mounted on the axlebox;

Figures 4 a to 4 e are face, top, bottom, right and left side views respectively of the adapter according to one embodiment; and

Figure 5 is a perspective view of the left part of the railway bogie assembly according to another embodiment.

Figure 1 and 2 show views of the railway bogie assembly 1 of the so-called Y 25 type. The railway bogie 1 comprises two axleboxes 2 whereby their housings 3 enclose at least one rolling bearing (not shown) for supporting each one end of rotatable axles (not shown) having a rotation axis X-X' . Each pair of wheels 4 is fixed to one rotatable axle. Since the left and the right axlebox assemblies are identical, the following drawing description will only describe the left railway bogie side.

Each axlebox 2 is extended to the left and the right side by two link arms 5 on which suspensions 6 are mounted on each of said link arms 5 . The link arms 5 and their associated suspensions 6 are symmetrical about a substantially vertical axis Χχ-Χι ' through the middle of the axlebox 2. The vertical axis Χχ-Χι' is perpendicular to the substantially horizontal axis X-X' .

The railway bogie assembly 1 also comprises a bogie frame 7 which is mounted on the axleboxes 2 via the suspensions 6 and an adapter 100.

The adapter 100 comprises a first bracket 101 and a second bracket 102 at each end, linked together by an elongated part 105. An assembling plate 103, 104 is fast with the bottom surface of the first bracket 101 and the second bracket 102 respectively.

The first bracket 101 is dedicated to be positioned under the horizontal section 115 of the bogie frame 7.

The first bracket 101 comprises a lateral wall 106 which is parallel with the vertical axis Χχ-Χι' . The cross-section along a horizontal plane X ₂ -X ₂ ' of the lateral wall 106 has a U-shape. According to the Figures 2, 3 and 4a to 4e, a side wall 107 which is a plane surface is fast with the lateral wall 106. An inner empty volume 116 defined by the walls 106, 107 defines a lower surface S ₂ and an upper surface Si. The lower surface S ₂ is covered by the assembling plate 103 on the underside and the upper surface Si is covered on the top by the elongated part 105

The inner empty volume 116 is such that the lower surface S ₂ is strictly greater than the upper surface Si. The side wall 107 is then inclined forming an obtuse angle β with the elongated part 105, and an acute angle a with the mounting plate 103.

The second end bracket 102 of the frame adapter 100 is placed under the inclined section 109 of the bogie frame 7. An inner empty volume 117 is defined by a surrounding wall 110, the elongated part 105 on the top, and the assembling plate 104 on the underside. The said surrounding wall 110 is parallel to the vertical axis Χχ-Χι' .

The elongated part 105 is provided with an inclined end 118 which is located under the inclined section 109 of bogie frame. This inclined end 118 is provided with an upper opening 112 above the second bracket 102. Therefore tools can be inserted during manufacturing and/or upper part of assembling means 8 can fit in the elongated part thickness.

Each assembling plate 103, 104 is mounted upon an assembling surface 9, 10 respectively defined on the top of each suspension 6 The assembling plates 103, 104 are provided with an assembling opening 108, 111 respectively in which assembling means 8 are inserted for attaching the adapter 100 to each suspension 6 of the axlebox 2.

Both brackets 101 and 102 are rigidly maintained to the elongated part 105 by rigidity means 113, 114.

In the embodiment illustrated in Figure 5, on which similar parts bear the same references, an adapter 300 comprises a first bracket 301 and a second bracket 302 at each end, linked together by an elongated part 305.

In this embodiment, the first bracket 301 comprises a lateral wall 106 having a U-shape and the extreme end surface of the bracket 301 is a recess 307. The inner empty volume 116 defined by the lateral wall 106 and the recess 307 is covered on the top by the end of the elongated part 305 and on the underside by the assembling plate 103. This inner empty volume 116 is such that the lower surface covered by the assembling plate 103 is strictly greater than the upper surface covered by the end of the elongated plate 305. The recess 307 has an inclined plane shape and forms an obtuse angle with the elongated part 305, and an acute angle with the assembling plate 103.

The second end bracket 302 is such that the elongated part 305 is directly attached to the surrounding wall 110 and does not cover the second bracket empty volume 117. The upper inclined surface 309 is then provided with a wide upper opening 312 in which tools can be inserted during manufacturing and/or upper part of assembling means 8 engaged in opening 111 can fit.

According to another aspect of the invention, a railway coach (not shown) is mounted upon the railway bogie 1 and directly supported by the bogie frame 7 for permitting the railway coach displacement on rail tracks. Moreover, one can mounts two railway bogies 1 at each end of the railway coach for supporting it.