Hydromechanical wheelset control system for a rail vehicle

Abstract

A hydromechanical wheelset control system for a rail vehicle that comprises a leading wheelset and a trailing wheelset that is arranged behind the leading wheelset in the direction of locomotion, with the trailing wheelset having the property of adopting a favorable position in an arc of an undercarriage frame interacting with it and of a rail pair. The wheelset control system is characterized in that a wheelset control is provided that is connected to the leading wheelset control system and to the trailing wheelset control system and that is adapted to hydraulically deflect the leading wheelset in dependence on a deflection of the trailing wheelset, preferably by the same amount as the trailing wheelset, but in the opposite direction.

Claims

1. A hydromechanical wheelset control system for a rail vehicle, comprising: a leading wheelset; a trailing wheelset that is arranged in a direction of locomotion behind the leading wheelset; and a pump for providing energy for hydraulic deflection of the leading wheelset, with the pump being flanged to an end of a wheelset shaft of the leading wheelset or of the trailing wheelset and being coupled to this wheelset shaft at a drive side, wherein the leading wheelset is adapted to vary its position in an arc of a rail pair interacting with it, and wherein a wheelset control is provided that is connected to the leading wheelset and to the trailing wheelset and that is adapted to hydraulically deflect the leading wheelset in dependence on a deflection of the trailing wheelset, and the leading wheelset and the trailing wheelset are arranged in an undercarriage frame and a position of the leading wheelset or of the trailing wheelset in the arc of the rail pair interacting with the respective wheelset is defined by a longitudinal movement between the undercarriage frame and a respective wheelset bearing.

2. The wheelset control system in accordance with claim 1, wherein the trailing wheelset is guided practically freely or elastically with a specific stiffness in the undercarriage frame to adopt a desired radial and/or overradial position in the arc of the rail pair under all wheel/rail conditions.

3. The wheelset control system in accordance with claim 1, further comprising at least one control valve, wherein the control valve: is mechanically or electromechanically actuable by the deflection of the trailing wheelset to bring the control valve into a deflection position that has a result of hydraulically deflecting the leading wheelset in an opposition direction to the trailing wheelset; and is mechanically or electromechanically actuable by the deflection of the leading wheelset to bring the control valve into a blocking position that stops a further hydraulic deflection of the leading wheelset on reaching a desired deflection; wherein the pump is switched into an idling state in the blocking position so that no power loss occurs.

4. The wheelset control system in accordance with claim 3, wherein a mechanical actuation of the control valve for moving into the deflection position takes place via a first push-pull cable and for moving into the blocking position takes place via a second push-pull cable, wherein the first push-pull cable reproduces a displacement angle of the trailing wheelset with respect to the undercarriage frame and the second push-pull cable reproduces the displacement angle of the leading wheelset with respect to the undercarriage frame.

5. The wheelset control system in accordance with claim 4, wherein the mechanical actuation of the control valves takes place by means of the push-pull cables that are arranged between the undercarriage frame and a railcar body so that a displacement angle of the undercarriage frame with respect to the railcar body is used as a control value for the railcar body.

6. The wheelset control system in accordance with claim 4, further comprising at least one travel direction valve per wheelset, for switching over the wheelsets from leading to trailing and vice versa, that is switchable by a differential pressure characterizing a direction of rotation between a suction side and a pressure side of the pump coupled to the wheelset shaft.

7. The wheelset control system in accordance with claim 1, wherein the wheelset control is provided with a dead travel to avoid unwanted control effects at higher speeds on straights and at large arcs.

8. The wheelset control system in accordance with claim 6, wherein both the trailing wheelset and the leading wheelset can be deflected via a respective actuation cylinder, with two chambers of the respective actuation cylinders being connected via a small restrictor plate so that the associated wheelset can move independently into a center position on the straight and tolerances can thus be compensated.

9. The wheelset control system in accordance with claim 8, wherein the chambers of the actuation cylinder of the trailing wheelset are short circuited via the travel direction valve that has an integrated restrictor plate.

10. The wheelset control system in accordance with claim 6, wherein an installation of the control valve and of the travel direction valve is provided pairwise at a respective wheelset mounting so that two control valves and two travel direction valves are present in leading and trailing wheelsets.

11. The wheelset control system in accordance with claim 10, wherein the travel direction valves reveal their adopted positions by different colorings of a respective valve plunger.

12. The wheelset control system in accordance with claim 6, wherein two actuation cylinders are present per wheelset that engage at different sides of the wheelset in a width direction perpendicular to the travel direction.

13. An undercarriage of a rail vehicle having a hydromechanical wheelset control system in accordance with claim 1.

14. A rail vehicle comprising an undercarriage in accordance with claim 13.

15. The hydromechanical wheelset control system for a rail vehicle according to claim 1, wherein a control wheelset is dependent on the deflection of the trailing wheelset by a same amount as the trailing wheelset, but in an opposite direction.

16. The wheelset control system according to claim 4, wherein the respective push-pull cable is coupled to an actuation cylinder of the associated wheelset.

17. The wheelset control system in accordance with claim 8, wherein a diameter of the restrictor plate differs in the leading wheelset and the trailing wheelset, such that the leading wheelset has a higher damping than the trailing wheelset.

18. The wheelset control system in accordance with claim 11, wherein a valve pin can also be recognized from outside through an inspection window.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Further features, details and advantages will become visible with reference to the following description of the Figures. There are shown:

(2) FIG. 1: a schematic representation of the present invention,

(3) FIG. 2: a schematic representation of the hydraulic circuit diagram of the present invention that achieves the advantages in accordance with the invention independently of the travel direction; and

(4) FIG. 3: a schematic plan view of an undercarriage of a railcar body frame having the wheelset control system in accordance with the invention.

DETAILED DESCRIPTION

(5) FIG. 1 shows the basic principle in accordance with the invention of a greatly simplified schematic representation.

(6) The hydromechanical wheelset control system 1 has a leading wheelset 2 and a trailing wheelset 3 (not explicitly shown) whose position in the track can be varied by an actuation cylinder 12 associated with the wheelset 2, 3. It can be recognized that the two actuation cylinders 12 are deflected by a relatively large amount in opposite directions to one another, which indicates a track curve having a relatively small radius. A change of the actuation cylinder 12 here also always results in a change of the wheelset 2, 3. connected thereto.

(7) It is now the idea of the invention to hydraulically adapt the leading wheelset 2 with reference to a deflection of the trailing wheelset 3 taking place automatically.

(8) To obtain a free or elastic or adaptable trailing wheelset 3, the two chambers of the actuation cylinder 12 belonging to the trailing wheelset are short circuited via a restrictor 16. It is accordingly possible that the trailing wheelset adjusts itself in the track on the basis of an external force effect so that in a track curve the trailing wheelset previously aligned as straight adopts a desired radial position or even an overradial position.

(9) If, however, the position of the trailing wheelset 3 or the position of the associated actuation cylinder 12 changes, this has effects on a control valve by means of a first push-pull cable 9.

(10) This control valve, that is implemented by a 4/3 valve in FIG. 1, adopts its center position when both actuation cylinders are deflected in equal but opposite amounts.

(11) If in contrast a change in the position of the trailing wheelset is determined via the push-pull cable 9, it is set into one of its two deflection positions. The actuation cylinder 12 of the leading wheelset therein is brought into connection with a pressurized hydraulic fluid so that the leading actuation cylinder is moved in the opposite direction to the trailing cylinder 12.

(12) If, for example, the piston of the trailing cylinder moves to the right, the first push-pull cable has the result that the high pressure side of the hydraulic pump 6 is connected to the right chamber of the leading actuation cylinder, which brings about a position change of the leading wheelset. If the actuation cylinder is located on the oppositely disposed undercarriage side, the high pressure side of the hydraulic pump 6 is logically connected to the left chamber of the leading wheel actuation cylinder.

(13) Only when the deflection that is equal but opposite in amount has been reached does the second push-pull cable 10 have the result that the deflection position of the control vale 8 is displaced toward the blocking position or center position of the control valve 9. In this center position of the control valve 8, the high pressure side and the lower pressure side are short circuited so that the pump 6 works in an idling state.

(14) So that the leading actuation cylinder 12 can also carry out smaller corrections in the center position of the control valve 8, the two chambers of the actuation cylinder 12 can be connected via a restrictor 15 (not shown in FIG. 1) that permits a very much smaller throughflow than the restrictor 16.

(15) FIG. 2 now shows a hydraulic scheme of the hydromechanical wheelset control 1, whose basic idea corresponds to the scheme of FIG. 1, for a structure independent of the travel direction that has a control valve and a travel direction valve per actuation cylinder 12.

(16) In this respect, travel direction valves that deliver the high pressure of the pump 6 running in different directions depending on the travel direction to the leading wheelset 2 or to the associated leading actuation cylinder 12 are now present to detect the trailing and the leading wheelset. A separate control valve 8 is furthermore also present for each actuation cylinder 12, with that one of the trailing wheelset 3 being decoupled from the high pressure side of the pump 6 with the aid of the travel direction valve 11 so that any switching position changes of the trailing control valve 8 do not develop any effect.

(17) The representation of FIG. 2 applies to an undercarriage 5 having one respective actuation cylinder 12 per wheelset 2, 3. The function here substantially corresponds to the procedure already explained with reference to FIG. 1. A pull-push cable 10 is fastened to the wheelset mounting at the respective trailing wheelset 3 and transfers the longitudinal movement between the undercarriage frame 5 and the wheelset bearing to the control valve 8, here a 4/3 way valve at the leading wheelset 2. On an actuation of the control valve 8, the actuation cylinder 12 of the leading wheelset 2 is pressurized so that it moves in the opposite direction to the trailing wheelset 3 until it reaches the same setting as that of the trailing wheelset 2. The control valve 8 is then again automatically moved into its center position in which the cylinder 8 practically hydraulically blocks and the pressure and return line is short circuited by the pump 6 so that the pump 6 no longer has to produce any pressure and practically does not generate any power loss.

(18) The energy or the pressure for the setting is generated by a pump 6 that can be a gear pump that is fanged to the wheelset shaft end and is driven by the rotational movement of the wheelset 2, 3. The volume flow is then aligned via four check valves 19 depending on the travel direction and is forwarded to the valves 8, 11 of the cylinders 12. A relief valve 26 and a hydraulic store 21 complete the pressure supply. A closed system is produced by the use of a hydraulic store 21 that is operated in the return and at low pressure and practically no idle power is produced while idling. The check valves 19 and the hydraulic store 21 can be directly integrated at the pump 6 or also in one of the optionally present valve blocks 23. Alternatively, an open system without a pressure store, but with a simple oil sump is also conceivable.

(19) In addition, an installation of an additional pressure store on the pressure side can be provided for a brief power increase so that suddenly occurring tight track curves such as typically occur at switches can preferably be traveled through on using the advantages of the invention due to an additionally accelerated actuation that is possible due to the additional pressure store. It is, however, naturally also possible to dimension the already present pressure store as sufficiently powerful.

(20) The chambers of the actuation cylinder 12 of the trailing wheelset 3 are short circuited via a restrictor plate 16 via a hydraulic servo control dependent on the direction of rotation, embodied by the travel direction valve 11, here a 6/2 way valve, so that the trailing wheelset 3 can adopt its radial or overradial position in the track practically freely and without delay, but damped. In addition, the trailing wheelset 3 is decoupled from the pressure and suction side (or tank side) via the travel direction valve 11. The chambers of the actuation cylinder 12 at the trailing wheelset 2 are released by the travel direction valve 11 to the control valve 8 so that a control via the control valve 8 connected to the leading wheelset 2 is made possible. The travel direction valves 11 are actuated, for example, by the changing pressure difference at a dual-action gear pump 6 on a forward or rearward travel (direction of rotation reversal) via hydraulic control lines 17. In addition, the travel direction valves 11 are brought into a base position via springs so that no undefined positions can occur. This is specifically of advantage in a standstill of the rail vehicle when no effective pressure difference is present at the pump 6.

(21) The wheelset control 4 can furthermore have a dead travel so that no dynamic control of the leading actuation cylinder 12 that would negatively influence the handling of the vehicle occurs at higher speeds and in large arcs of the track. This dead travel is implemented via a positive covering of the valves 8. In addition, the two chambers of each actuation cylinder 12 are connected to one another via a small restrictor plate 15 so that a very high damping of the movement is produced. This enables the wheelset 2, 3 to align itself independently in the center position on the straight and thus to compensate tolerances and errors in the settings.

(22) As shown in FIG. 3, one respective valve block 23, comprising a control valve 8 and a travel direction valve 11, is preferably fastened to a wheelset mounting (e.g. rocker arm, wheelset bearing housing, axle guide, etc.) and is connected to the oppositely disposed wheelset mounting via two push-pull cables 9, 10. The cables 9, 10 are each fastened at alternate sides at the valve body or at the valve actuation rod. The two cables 9, 10 can be combined together with the three or our hydraulic lines 17, 18 (pressure, return, and control line(s)) in a protective tube 22 or protective pipe and are correspondingly laid in the bogie. A control system 4, comprising two valve blocks 23, two push-pull cables 9, 10, the three or four hydraulic lines 17, 18, and the pump 6, can be preassembled in this form on manufacture so that laborious setting work is no longer required on the installation at the undercarriage 5. The system 4 is thus installation and maintenance friendly.

(23) The pump 6 and the hydraulic lines 18 starting from it are as a rule dimensioned such that high stroke speeds are achieved to reach the full deflection when traveling through switches even before the critical locations such as the frog.

(24) Provision can be made here that the cross-sectional apertures of the valves 8 have a progressive form so that the positioning accuracy with small apertures is improved.

(25) FIG. 3 further shows that the pump 6 can preferably be directly attached to the wheelset shaft end. There is thus no additional space requirement within the undercarriage 5 since this is anyway very tight in most cases. The check valves 19 and the hydraulic store 21 are preferably directly integrated in the valve block 23.

(26) An approximately 6-8 times faster response time than with classical arc recognition systems—such as via the displacement angle of the undercarriage or an arc recognition sensor system (gyroscopes, accelerations, etc.)—can be achieved by the use of the trailing wheelset 3 as the control or regulation value so that the control in accordance with the invention can also produce the required high performance when traveling through switches. The power or the conveying volume of the pump 6 can be dimensioned such that the setting speed at 40 kph is sufficient to achieve the total stroke before reaching the frog of a switch.

(27) In accordance with the invention, a state display in the form of a pressure monitoring can furthermore also be provided that either generates a display purely mechanically or takes place electronically via an LED display. The power supply of this monitoring takes place, for example, via a capacitor that is charged by the system itself via conversion of pressure changes into voltage.

(28) In addition, an inspection window can be installed at the valve block that permits the visual monitoring of the position of the travel direction valve 11 for the travel direction change. If one of these valves should be blocked, different positions would be able to be recognized in both valves. A display pin is alternatively also possible that is raised or lowered via the valve plunger.

REFERENCE NUMERAL LIST

(29) 1 hydromechanical wheelset control system 2 leading wheelset 3 trailing wheelset 4 wheelset control 5 undercarriage/undercarriage frame 6 pump 7 wheelset shaft 8 control valve 9 first push-pull cable 10 second push-pull cable 11 travel direction valve 12 actuation cylinder 13 chamber, actuation cylinder 14 chamber, actuation cylinder 15 restrictor plate 16 restrictor plate integrated in the travel direction valve 17 differential pressure control line 18 hydraulic line 19 check valve 21 hydraulic store 22 protective tube 23 valve block 24 fastening 25 fixed point for push-pull cable 26 relief valve