WO2001007279A1

WO2001007279A1 - Device for improving the steerability of driven axles

Info

Publication number: WO2001007279A1
Application number: PCT/EP2000/006033
Authority: WO
Inventors: Otto Becker
Original assignee: Grove U.S. Llc
Priority date: 1999-07-27
Filing date: 2000-06-28
Publication date: 2001-02-01
Also published as: CN1373717A; EP1200282A1; CA2380247A1; JP2003505290A; KR20020019585A; DE19935160A1

Abstract

The invention relates to a device for improving the steerability of driven axles. A central transmission transfers driving torque to steered wheels via drive shafts. The central transmission is mounted in such a way that it can rotate around a vertical axis.

Description

Grove U.S. LLC

1565 Buchanan Trail East

Shady Grove, Pennsylvania 17256, U S A

Device for increasing the steering ability of driven axles

The present invention relates to a device for increasing the steering ability of driven axles, in which a central torque transmits the torque via drive shafts to steered wheels. In particular, the present invention can be used in multi-axle vehicles that have individually suspended and attached wheels on steered axles, for example, traveling cranes

In the case of such traveling cranes, the currently attainable maximum wheelbase on driven axles in two- and three-axle vehicles is approximately 38.5 °. The cardan shafts, which connect the central gearbox with the wheel axles, were designed with a maximum steering angle of 42 ° in the case of independent wheel suspensions, the steering movements with the deflection and rebound movements of the shock absorbers, so that a total of only a steering angle of approximately 37.5 ° at a deflection angle of 42 ° with maximum deflection and deflection are achievable. In order to increase the maneuverability of such vehicles, however, the aim should be to achieve the highest possible steering angle.

From DE 36 02 400 AI an arrangement of an axle shaft in a wheel suspension is known. It is proposed to arrange the center gear horizontally displaced from the center of the axle in order to optimize the resulting steering angle. These measures can increase the maximum steering angle to approximately 39 °. However, this somewhat higher steering angle still needs to be improved.

It is therefore the object of the present invention to provide a device by means of which the maneuverability of vehicles with driven axles can be increased significantly. In particular, the ability to steer should be significantly increased by enabling very large steering angles.

This object is achieved in that the center gear of the respective driven axis is rotatably supported about a vertical axis. Advantageously, a rotation of the center gear around this axis can then improve the position of the elements of the drive relative to one another to the extent that very large resulting steering angles can be achieved. This more than compensates for the loss in the maximum steering angle caused by the compression and rebound of the struts. In other words, the center gear is enabled to take a twisted position that allows drive elements such as the propeller shafts (which are attached to the center gear and wheel drive with universal joints) to take positions that allow an optimally increased steering angle. The additionally created degree of freedom of the rotary movement of the central transmission therefore allows an optimization of the resulting steering angle, which can reach 45 °, for example, even when using conventional drive components. With that the Maneuverability of appropriately equipped vehicles is significantly increased.

In one embodiment of the device according to the invention, the center gear is mounted under the frame on a rotary bearing fixedly attached to the frame. The center gear can be mounted so that it can rotate at least by an angle of about 10 ° in both directions about the vertical axis.

In a preferred embodiment of the invention, the center gear is connected to the steering in such a way that it can rotate proportionally according to the axle steering in the opposite direction to the wheel lock, or can be deflected in this way. This deflection opposite to the wheel lock creates the necessary freedom of arrangement for the drive cardan shafts in order to generate the resulting high steering angle. It is conceivable within the scope of the invention to connect the central transmission to and disconnectable from the steering in order to be able to use the steering mechanism according to the invention in a controlled manner. For example, the deflection of the center gear can be switched off when driving straight ahead and switched on off-road or when cornering tightly.

In one embodiment of the device according to the invention, the central transmission can be deflected via a coupling rod articulated on the steering lever of a wheel and a deflection lever articulated thereon. Specifically, the steering lever connected to the coupling rod can be the steering lever of an axle to which the steering movement is transmitted from the opposite wheel steering lever via a track clip.

In order to be able to increase the resulting steering angle even further, according to the invention there is also the possibility of firmly arranging the central transmission horizontally offset from the center of the axle line, in particular offset forward in the vehicle longitudinal direction in order to further optimize the steering angle. Furthermore, it is it is also possible to arrange the center gear offset upwards or downwards in order to optimize the joint angles when the wheels are deflected and rebounded. With the help of this additional measure, steering angles of approximately 48 ° can then be achieved, which cannot be achieved with conventional axles.

The invention is explained in more detail below using exemplary embodiments with reference to the accompanying drawings. Show it.

Figure 1 is a view of a driven axis with an inventive

Arrangement of the Mitteng etπebes; Figure 2 an upper view of an axis in the original state;

Figure 3 eme view according to Figure 2 when cornering with a fixed

Center gear at 38 ° wheel lock; FIG. 4 shows a view of an axis designed according to the invention according to FIG

4 for cornering with a deflected center gear and max.

Rademschlag; Figure 5 eme embodiment of the invention, in which the center gear is fixed forward, but rotatably arranged, with max. Turn with the center gear deflected, (wheel turning 48 °), and Figure 6 shows a detailed positional representation of the steering and drive parts

Straight ahead and more direct at maximum impact

Confrontation

FIG. 1 shows a view of a steered driven axle between the two wheels 4 of a vehicle, here a mobile crane. The two suspension struts 7 are attached to the frame 18 and fix the wheels 4, which thus have an individual suspension and have a wheel drive 3 with planetary gears. The wheels are steered over the downwardly projecting parts of the Federbeme 7, namely via a steering mechanism, of which m a steering lever 10 and a tie rod 14 to m Figure 1 are seen. The function of the steering will be described in detail with reference to Figure 6.

The two wheels 4 are driven via the cardan shafts 2, which are provided on both sides with universal joints. The drive torque comes from the central gear 1, which is supplied in a conventional manner with the torque of the engine.

The center gear 1 is fixed to the frame 18 via the attachment 5, which has the rotary connection 6 at its lower end. This rotary connection 6 thus rotatably couples the center gear to the mounting 5, in such a way that it can be deflected about the vertical axis 20 in both directions of rotation.

This interpretation takes place in the steering via a coupling rod 8, which is connected to the steering lever of the right wheel 4 and is also articulated on the deflection lever 9, which in turn is firmly seated on the central transmission 1 at its other end.

With this construction, the central transmission 1 can be rotated about the axis 20 according to the invention in the event of a steering lock by the deflection lever 9, in order to achieve the desired high steering locks. The later description of FIG. 6 will provide more detailed information about the steering kinematics used.

The principle of operation of the device according to the invention will now be described with reference to FIGS. 2 to 5. The figures are top views of an axle with two individually suspended, driven wheels. In simple terms, according to FIGS. 2 to 5, the steering movement is transmitted via a steering rod 13 on an arm of the steering lever 10 of the lower wheel 4, as can be seen most clearly in FIGS. 3 to 5. On the other arm of the steering lever 10, the tie rod 14 engages, which the steering force on the steering lever of the upper Transmits the wheel and steers it. In general, it applies to the representations of FIGS. 4 and 5 that the central transmission 1 is coupled to the steering. The coupling is shown in detail for an embodiment of the invention in FIG. 6 and will be explained in detail later. However, the basic principle of the invention can be explained in an understandable manner in the following on the basis of FIGS. 2 to 5, without going too much into the details.

FIG. 2 shows a state which shows the axle without being influenced by a particular driving state and which could be called the "original state". If the connecting line of the two projected wheel steering axles is referred to as the axle line, the vertical axis 20 of the central transmission, which appears point-like in this view, lies 1 in this "original state" on the axle line, and the steering rod 13, the steering lever 10, the tie rod 14 and the cardan shafts 2 are arranged with the central gear 1 not rotated so that the wheels 4 are not steered. This is the state of this axis when driving straight ahead.

An axis with a wheel lock for a right turn is shown in FIG. 3. This right-hand curve is also still driven without the maximum possible steering lock supported by rotation of the center gear 1, and it becomes clear that with such a conventional "steering lock" only a steering angle of 38 ° can be achieved. The steering angle here is the angle between the axis of rotation of the steered wheel and the line connecting the two points around which the wheel steering rotation takes place, which are always on the respective longitudinal axis of the struts.

In FIGS. 4 and 5 it is now clear how the resulting steering angle can be increased according to the invention by means of a rotatably mounted central gear 1. FIG. 4 shows a state in which the vertical axis 20 of the center gear 1 lies on the line which in this projection is the longitudinal axes of the Suspension struts 7, i.e. the wheel steering axles connects. The state of a full turn on a right-hand bend is also shown here, but a resulting steering angle of 45 ° is achieved here. This is because the center gear 1 is deflected according to the invention in its rotatable mounting, in a direction of rotation opposite to the wheel lock. Thus, if the wheels in FIG. 4 turn counterclockwise, the center gear is rotated clockwise around the vertical axis 20, in the present embodiment approximately 10 °. Here, those universal joints of the cardan shafts 2, which are attached directly to the central gear 1, are moved in their longitudinal position; the above connection point between center gear 1 and cardan shaft 2 slides further to the right (rear) in FIG. 4, while the lower connection point between cardan shaft 2 and center gear 1 moves somewhat to the left (front). This shift in position and the associated rotation of the cardan shafts create a certain clearance angle at the respective point of connection of the cardan shafts with the wheel drive, which can be used for a further turning of the wheels. The universal joints on the wheel drives thus receive additional freedom of movement for turning the wheels 4 more strongly by rotating the central transmission 1.

This enables the resulting high steering angle of 45 ° to be achieved.

The steering angle can be optimized even further in a construction as shown in FIG. In this axis, the center gear is fixed so that the vertical axis 20 is slightly in front of the connecting line of the projected wheel steering axles 7. This results in a further shift in the kinematics, which results in the lower wheel 4 being able to be deflected up to a resulting steering angle of 48 °. This also takes place when the center gear 1 is deflected by only 10 °. With the help of Figure 6 is now shown in detail how a steering according to the invention takes place in detail. FIG. 6 shows two states, namely the deflected state in solid lines and the state for driving straight ahead in broken lines in order to make the changes in position of the components visible. Starting from the hydraulic steering system 17, the force is transmitted via the steering rod 13 to the lower steering lever 10 on its left arm. The steering cylinder is also on this left arm of the steering lever 10

11 articulated, which is hinged at its other end to a fixed location in the vehicle.

About the right arm of the steering lever 10, the steering activity is transmitted to the steering lever 10 'shown above of the other wheel by means of the tie rod 14. As a result, the two wheels 4 are steered in the same direction.

The steering lever 10 'also has an articulated attachment point for the coupling rod

12, which in turn is articulated at the other end to the deflection lever 16. This deflection lever 16 is then firmly connected at its other end to the central transmission 1, so that rotation of the rotatably mounted central transmission 1 takes place via the rotation of the steering lever 10 ', the coupling rod 12 and the deflection lever 16, in the direction of rotation always opposite to the direction of impact of the wheels. By turning the center gear, the increased and optimized maximum wheel lock angle is achieved according to the invention, in the manner as described above with reference to FIG. 5. With this increased steering angle of the wheels, a corresponding improvement in the maneuverability of the vehicle is achieved.

Claims

claims

1. Device for increasing the steering ability of driven axles, in which a central gear (1) transmits the drive torque via drive shafts (2) to steered wheels (4), characterized in that the central gear (1) is rotatably supported about a vertical axis (20) is.

2. Apparatus according to claim 1, characterized in that the central gear (1) is mounted under the frame (18) on a fixed to the frame (18) attached pivot bearing (6)

3. Apparatus according to claim 1 or 2, characterized in that the central gear (20) is mounted so that it can rotate at least by an angle of about 10 ° m in both directions about the vertical axis (20).

4 Device according to one of claims 1 to 3, characterized in that the central transmission (1) is connected to the steering, in particular connected and disconnected, and can be deflected in proportion to the axle steering in the opposite direction to the wheel beat.

5 Device according to one of claims 1 to 4, characterized in that the Mittengetπebe (1) via eme on the steering lever (10, 10 ') of a wheel (4) articulated coupling rod (12) and a articulated to this lever (16) can be deflected

6 Apparatus according to claim 5, characterized in that the steering lever (10 ') connected to the coupling rod (12) is the steering lever of an axle on which the steering movement via a tie rod (14) is from that opposite wheel control lever (10) is transmitted.

7. Device according to one of claims 1 to 6, characterized in that the center gear (1) is fixed horizontally or vertically offset from the center of the axle line, in particular in the vehicle longitudinal direction forward to further optimize the steering angle.

8. Device according to one of claims 1 to 7, characterized in that the central gear (1) can be deflected such that a steering angle of the wheels (4) of 45 °, and with an optimized arrangement of the central gear (1) according to claim 7, a steering angle of 48 ° compared to the axis line.