GB2029785A

GB2029785A - Rail Vehicles With Power Bogies

Info

Publication number: GB2029785A
Application number: GB7929250A
Authority: GB
Original assignee: Fried Krupp AG
Current assignee: Fried Krupp AG
Priority date: 1978-08-26
Filing date: 1979-08-22
Publication date: 1980-03-26
Also published as: AT365524B; FR2434067A1; CH639328A5; DE2837302A1; DE2837302C2; JPS5531691A; IT7925190A0; GB2029785B; FR2434067B1; ATA559079A; SE7906787L; IT1122804B; SE445632B

Abstract

For increased stability at high speed, the driving unit (e.g. motor 14) of each bogie is so supported on the bogie frame 1 by springs and damping elements that it is movable linearly in a transverse direction and rotatable about a vertical axis with respect to the bogie frame to the same extent as the latter is movable with respect to the track. <IMAGE>

Description

SPECIFICATION Rail Vehicle with Bogies This invention relates to a rail vehicle equipped with bogies and having at least one driving unit.

In travel of a driven rail vehicle horizontal oscillations become disturbing as the speed increases, these generally being composed of a generally translatory oscillation in a direction transverse to the rails and a rotational oscillation about a vertical axis superposed to produce a hunting motion, the so-called sinusoidal bogie movement. There is accordingly a risk of the amplitudes of these movements becoming excessive.

To avoid this, attempts have been made in known driven rail vehicles, to attune to one another the stiffness and damping characteristics of the springs and damping elements, which connect the wheel sets, the bogie and the frame of the vehicle, in optimum fashion having regard to the masses of these parts of the vehicle. Thus vehicles of the above kind are known in which damping devices are provided between the bogie frame and the vehicle frame to limit the rotational oscillations of the bogie frame.

These measures do not however provide satisfactory stability in travel in the speed range well above 200 km/h. The driving unit, for example a motor, on the frame and the associated transmission gearing, are so supported by springs in the known rail vehicles that only vertical impacts from the bogie frame upon the driving unit are diminished. In the transverse direction these spring elements are almost rigid so that the mass of the driving unit or units is directly coupled to the bogie frame for oscillation in the transverse direction.

To obviate this, the driving motors are transferred in other known rail vehicles from the bogie frame into the frame of the vehicle. With this arrangement the mass ratio in the bogie is improved from the viewpoint of oscillation but, since travelling in a curve involves large movements of the vehicle frame in relation to the wheel sets, the mechanism for the wheel sets becomes complicated and massive, and is liable to disturbance. Also this construction often involves additional heavy elements because space for the driving unit in or under the vehicle frame can only be provided by increasing the length of the vehicle frame. In addition, with these known rail vehicles part of the driving unit, namely the axle drive, must necessarily remain in the bogie frame.

The object of the invention is to provide a rail vehicle of the above kind which provides high stability in travel and in which the critical speed, which is characterised by periodic movement of the treads of the wheel sets at about 1 to 5 Hz during straight travel, can be increased substantially above 200 km/h. In addition the above disadvantages of the known rail vehicles are to be avoided.

This problem is solved in accordance with the invention in that each driving unit is mounted in the bogie frame for translational movement in the transverse direction to substantially the same extent and for rotational movement about a vertical axis to substantially the same extent as the bogie frame is movable with respect to the rails, each driving unit being connected to the bogie frame by at least one spring and at least one damping element.It is desirable to arrange that the stiffness of the spring or springs is such that the oscillations transversely to the direction of travel of each driving unit with respect to the bogie frame and the corresponding rotational oscillations about the vertical axis have a frequency up to a maximum of about 5 Hz, and that the damping characteristics of the damping element or elements are so attuned to the frequency and amplitude of the oscillations of each driving unit that the whole system of the bogie is stable in oscillation up to a prescribed maximum speed. The feature of claim 5 provides an advantageous suspension of the driving unit.

The feature of claim 6 simplifies the driving problem while the features of claims 4 to 8 enable the spring stiffness for the translational movement of a driving unit in the transverse direction and for the rotational movement about a vertical axis to be determined independently of one another.

A number of embodiments of the invention will now be further described with reference to the drawings, in which: Fig. 1 shows a bogie for a rail vehicle according to the invention with two axles and a driving unit for both axles; Fig. 2 shows a bogie with two axles driven by separate driving units; Fig. 3 shows a bogie with two driving units providing separate drives mounted on a commom frame; Fig. 4 shows a bogie with a driving unit supported by a pendulum formed by a pair of torsion bars and driving two axles; and Fig. 4a shows a damping unit between the driving unit and the frame of the bogie shown in Fig. 4.

Figs. 1-4 are perspective views and Fig. 4a is a plan. The drawings are schematic and show essential features only.

The bogie frame 1 consists of two side members 2 and two end members 3. The bogie frame has two axles 4, each carrying two wheels 5 which run on the rails 6.

As shown in Fig. 1. the bearings 7 of the axles 4 are connected individually to the bogie frame 1 by a spring 8 in the longitudinal direction, i.e. the direction of travel, by a spring 9 and a damping element 10 in the vertical direction and by a spring 11 and a damping element 12 in the transverse direction, i.e. at right angles to the direction of travel. For simplicity, the springs 8 and the pairs of springs and damping elements 9,10 and 11,12 are shown in chain-dotted lines only in Figs. 2-4. To take the vertical forces each bearing 7 is provided with a mounting 13 on the side members 2.

In the embodiment shown in Fig. 1, both axles 4 are driven by a single driving unit 14. The driving unit 14 is substantially symmetrical with respect to a vertical axis 1 5. The driving unit 14 is connected at both sides to the side members 2 of the bogie frame 1 by a spring 1 6 and a damping element 17, each forming a pair spaced by a distance 1from the vertical axis 1 5 so that the spacing of the pairs is 21 as shown in Fig. 1.

Power and torque can be transmitted from the driving unit 14 to the axles 4 by any known mechanism suitable for optimal realization of the necessary spring and damping characteristics. In the embodiments shown in Figs. 1 to 4 a hollow shaft 18 of known construction is provided, which is connected by cardan joints to the driving unit 14 or to gears 22 or 30 at one end and to a shaft 4 or wheel 5 at the other end. The axially effective spring and damping characteristics of the cardan coupiing of the hollow shaft are indicated in Fig. 1 by a substituted system controlled in each case by a spring 19 and a damping element 20.

The driving unit 14 is supported by the described arrangement of springs and damping elements 16,17 and 18,19 for respective transverse translatory movement and rotation about the vertical axis 1 5 in relation to the bogie frame 1.

The driving unit 14 is supported in the bogie frame 1 in the longitudinal direction and in relation to its longitudinal axis by known elastic rubber elements which afford little opportunity for movement of the driving unit 14 in respect to the bogie frame 1 in said directions. The vertical connection between the driving unit 14 and the bogie frame can be effected in known fashion by two pendulum links, as shown in Figs. 2 and 3, so that the above-described movements in the horizontal plane are possible.

In the embodiment shown in Fig. 2, each wheel set 4,5 has a separate drive constituted by a motor 21, gearing 22 and the hollow shaft 18.

The motors 21 are suspended by pendulum links 23 from members 24 of the bridge-like cross member 25 of the bogie frame 1 and connected longitudinally to the end members 3 of the bogie frame 1 by pins 22 and torque supports 26. The pendulum suspension permits movement of the motors in the transverse direction and the pins 27 permit each driving unit 21,22 to move about a vertical axis. Each of the units illustrated as a cylinder consists of a spring 16 and a damping element 17, these units being disposed at both sides between the motors 21 and the side member 2 of the bogie frame 1.

In the embodiment shown in Fig. 3 there are two independent drives, each consisting of a motor 21, gearing 22 and a hollow shaft 18.

These drives are combined by a frame 28 to form a commom unit from the viewpoint of oscillation.

The frame 25 is suspended in the manner already described by pendulum links 23 from the bogie frame 1 and supported on the bogie frame in the transverse direction by the units shown as cylinders and each constituted by a spring 1 6 and a damping unit 17. The driving assembly mounted on the frame 28 is therefore capable of translation in the transverse direction and also of rotation about the vertical axis 1 5 through the centre of the frame 28.

In the embodiment shown in Figs. 4 and 4a there is again a single driving unit, consisting of a motor 29 and two axle driving gear sets 30. The motor 29 is again suspended from the bogie frame 1 by pendulum links 31, but in contrast to the previous embodiment the upper ends of the pendulum links 31 are connected by torsionally stiff connectors 32 to torsion bars 33, which are rotatable in bearings in the cross bridge 25. The units, shown as cylinders and each consisting of a spring 16 and a damping unit 17, extend transversely between the axles 4 and are in alignment.

This arrangement has the advantage that the springs and damping elements for the translatory movement of the driving units 29,30, in the cross direction and for the rotary movement about the vertical axis 1 5 can be separately dimensioned.

During the translational movement the torsion bars are rotated by the links 31 in their bearings 34. The spring and damping characteristics are given by the units formed of the springs 1 6 and damping elements 1 7. During the rotational movement the links 31 on each side move in opposite directions so that the torsion bars 33 are twisted and exert a restoring force on the driving unit 29,30. The damping for the rotational movement of the driving unit is provided by at least one damping element 35 as shown in Fig.

4a. During rotational movement of the driving unit the units formed by the springs 1 6 and damping elements 1 7 remain practically inactive and during the translational movement the torsion bars 33 and the damping element or elements 35 are inactive.

Calculations based on a model of the embodiment shown in Fig. 1 have, after optimisation of the spring and damping characteristics for prescribed masses, established critical speeds far in excess of those for rail vehicles having bogies of known construction.

Claims

1. A rail vehicle equipped with bogies and having at least one driving unit, characterised in that each driving unit is mounted in the bogie frame for translational movement in the transverse direction to substantially the same extent and for rotational movement about a vertical axis to substantially the same extent as the bogie frame is movable with respect to the rails, each driving unit being connected to the bogie frame by at least one spring and at least one damping element.

2. A rail vehicle according to claim 1.

characterised in that the stiffness of the spring or springs is such that the oscillations transversely to the direction of travel of each driving unit with respect to the bogie frame and the corresponding rotational oscillations about the vertical axis have a frequency up to a maximum of about 5 Hz.

3. A rail vehicle according to claim 1 or claim 2, characterised in that the damping characteristics of the damping element or elements are so attuned to the frequency and amplitude of the oscillations of each driving unit that the whole system of the bogie is stable in oscillation up to a prescribed maximum speed.

4. A rail vehicle according to one of claims 1 to 3, characterised in that separate spring and damping element systems are provided for the translatory and rotational movements of each driving unit.

5. A rail vehicle according to one of claims 1 to 4, characterised in that each driving unit is suspended as a pendulum from the bogie frame.

6. A rail vehicle according to one of claims 1 to 5, characterised in that each bogie has a single driving unit.

7. A rail vehicle according to claim 6, characterised in that the transversely disposed springs and damping units are connected between the driving unit and the bogie frame at points spaced in the longitudinal direction and symmetrical with respect to the vertical axis of rotation.

8. A rail vehicle according to claims 4 to 6, characterised in that the pendulum support for the driving unit is connected by torsionally stiff connections to torsion bars journalled in the bogie frame and the units extending in the transverse direction between the driving unit and the bogie frame, and each consisting of a spring and a damping unit, are disposed in alignment centrally of the driving unit.