WO1992013213A1

WO1992013213A1 - Adjustable control gear for changing the transmission ratio in mechanical linear, pivoting and planetary systems

Info

Publication number: WO1992013213A1
Application number: PCT/EP1992/000100
Authority: WO
Inventors: Peter Graf Von Ingelheim
Original assignee: Peter Graf Von Ingelheim
Priority date: 1991-01-21
Filing date: 1992-01-20
Publication date: 1992-08-06
Also published as: DE4101562A1

Abstract

The invention concerns an adjustable control gear for changing the transmission ratio in mechanical linear, pivoting and planetary transmission systems, in particular for applications in pneumatic control units and vehicule steering systems. The transmission systems operate without toothed wheels or racks. The control gear (6...8) rotates about a spindle (9) fixed to the housing, thus changing continuously the transmission ratio in linear and pivoting transmission systems. In planetary transmission systems, a ratio-changing arrangement of this kind gives a transmission with two ratios 1:1 and 1:2. Connecting such two-stage planetary transmisson systems in series and in parallel enables multi-stage transmissions with very finely stepped transmission ratios to be designed.

Description

Adjustable guide gear for changing gear ratios in mechanical linear, part-turn and epicyclic gearboxes

The invention relates to an adjustable guide gear for changing gear ratios in mechanical linear, swivel and epicyclic gearboxes, in particular for applications in pneumatic controls and vehicle steering systems. DE 39 05 979 AI shows an adjustable guide gear for changing the transmission ratio, in which the adjusting element has to be moved with the target gear. This makes the entire adjustment gear a complicated and expensive lever mechanism, in which a movably arranged hydraulic cylinder appears necessary.

The invention seeks to remedy this. The invention makes it possible to change the translation of the target gear by rotating a guide element about an axis fixed to the housing and perpendicular to the movement path of the target gear such that either a changed constant gear ratio or a changed gear ratio dependent on the gear position is achieved. The adjustment can be done mechanically, electrically (e.g. with a stepper motor with self-locking worm gear, which prevents an unintentional adjustment of the gear ratio) or magnetically, hydraulically or pneumatically or depending on the current gear position.

With the transmission according to the invention, e.g. a linear guide is possible which has only mechanical elements and guides and which, at constant input speed and input force, initially produces high output speed and low output force and towards the end low output speed and high output force.

Guide gears should convert an initial movement into a second movement. Such gears are generally used in machines for generating an unchangeable second movement for a given first movement. With pneumatic cylinders or swivel motors, usually only two positions (stop control) can be approached. This severely limits the controllability of the pneumatics. For pneumatic applications, it would be expedient to be able to change the displacement length or the swivel angle of the output member with the aid of an adjusting gear, for example, for a given first movement, for example a linear displacement of constant length by means of a pneumatic cylinder or when pivoting by a constant angle by means of a swivel motor. In the case of pneumatic cylinders, however, it would also be expedient to increase the relatively low displacement forces of a pneumatic cylinder with the aid of a transmission or to convert the cylinder force and speed as a function of the respective cylinder position. In the case of vehicle steering systems, there is generally a constant assignment of changes in the steering wheel angle and the adjustment angle of the wheels. Steering systems are already known in which a turning of the steering wheel by an angle μ produces a different adjustment angle of the wheels when the steering wheel is turned sharply than when the steering wheel is turned slightly; for a given steering wheel angle, however, the translation is constant. However, direct steering is sought for higher speeds, for which purpose it makes sense to change the steering ratio as a function of the driving speed. In the case of four-wheel steering, it is also necessary to change the relative steering angle of the front and rear wheels. In the case of a forced coupling of the rear wheel steering to the front wheel steering and straight travel, an adjustment of the gear ratio of the transmission must not lead to a change in the position of the rear wheels. The invention serves this purpose. The invention makes it possible, by rotating a guide element which can be rotated about an axis which is immovable relative to the housing:

(1) continuously changing the transmission factor a / b of an initial linear movement of a length a into a second linear movement b,

(2) the transmission factor ul / μ.2 of an initial swiveling motion stepless change of the swivel angle μl into a second swivel movement of the swivel angle μ2, (3) to produce a multi-stage transmission between two shafts of an epicyclic gearbox without the use of gearwheels.

In all applications, roller-bearing guides and roller bearings can enable smooth, smooth-running and low-backlash or "backlash-free" gears.

The basic principle and exemplary embodiments of the transmission according to the invention and its use are explained in more detail with reference to the drawings; serve in it

Figures 1 and 2 of the explanation of the basic principle based on a linear feed, and Figures 3 to 6 of the explanation of a swivel or epicyclic gear.

Figure 1 shows a linear feed in perspective view as an "exploded view", Figure 2 shows various gear positions as a top view through "glass" elements.

A machine with a linear movement of constant length, e.g. a pneumatic cylinder, is connected to a drive slide 1, which has an oblique slot 2. An Abtriebs¬ slide 3 with a slot 3, which has a different slope than the slot 2, is parallel to the drive slide 1. Via a first sliding body 5, which is displaceable in the slots 2, 4, the drive slide 1 and Abtriebs¬ slide 3 connected together.

A guide element 8 is rotated with a pin 9 in the housing (not shown) about an axis perpendicular to the movement paths of the input and output slide. A second sliding body 6 is displaceable on the guide element 8, which is inserted with a sliding body pin 7 in the first sliding body 5 and can be rotated relative to the latter.

Figure 2 is used to explain the transmission function. FIG. 2a shows the position for one end stop of the drive slide 1 or of the pneumatic cylinder. This position is given for the one end stop with every gear setting. FIGS. 2b to 2d show different positions for the other end stop of the drive slide 1.

In Figure 2b, the guide element 8 is rotated upwards. The sliding body 5 slides backward in the slot 2 of the drive slide 1 and forward in the slot 4 of the driven slide 3. The output slide 3 is only shifted by a small length.

In FIG. 2c, the sliding body remains relatively stationary in both slots. The drawer length of the output slide is equal to the drawer length of the drive slide.

In Figure 2d, the guide element is rotated downwards. The sliding body slides forward in the slot of the drive slide and backward in the slot of the driven slide. The driven slide is shifted by a large length. FIG. 3 shows the basic principle in a perspective view, FIG. 3b showing the transmission according to FIG. 3a with the drive shaft 22 rotated by 180 °.

The structure will be explained with reference to FIG. 3a. A first roller bearing 20 can be rotated in the housing with a pair of pins 21. The pins 21 are on the axis of rotation of the drive shaft

22 and the output shaft 25 perpendicular. On the drive shaft 22, a second roller bearing 23 is fixed obliquely. In the cutting axis of the two rolling bearing planes, the outer ring of the second rolling bearing 23 is positively connected to the inner ring of the first rolling bearing, but is rotatable relative to it about the cutting axis.

On the output shaft 25 there is a fork with slots 26 parallel to the axis of rotation, through which the connecting element of the two roller bearings 20, 23 leads. It can be seen from FIG. 3b that in this position of the first roller bearing, a rotation of the drive shaft by 180 ° leads to a rotation of the output shaft by 90 °.

Figure 4 shows a section through Figure 3b along the slots in the fork of the output shaft. It can be seen that the inner ring 30 of the first roller bearing 20 is inserted with a pin 34 in a hollow pin 33 which is on the outer ring 31 of the second.

Rolling bearing 23 is fixed. The hollow pin 33 is in one Sliding body 32 rotatable, which can slide in the slot 26 of the output shaft 25 parallel to its axis of rotation.

FIG. 5 shows various settings of the transmission according to the invention, FIGS. 5a and 5b showing positions that are possible for swivel and rotating gears, while FIG. 5c shows a position that is only possible for swivel transmissions, the drive shaft being at most 180 ° may be rotated (in position 5c by 90 ° forwards or backwards). In FIG. 5a one has the setting of FIG. 3, in which a rotation of the drive shaft 22 leads to half a rotation of the output shaft 25.

In FIG. 5b, the plane of rotation of the first roller bearing 20 is perpendicular to the axes of rotation of the input and output shafts 22, 25. The two axes are thus coupled and have the same speed.

In Figure 5c you have different inclinations of the planes of rotation of the two bearings to the axes of rotation of the two shafts; you have a ratio between 1 and 2.

FIG. 6 shows the arrangement for a six-stage transmission according to the invention. Four gears of FIGS. 3 and 4 are arranged in series or in parallel. The drive shaft An drives the shaft D. By pivoting the bearing I, a 1: 1 or a 1: 2 ratio between shaft An and shaft d can be achieved. Shaft d drives shaft C. By pivoting bearing II, a 1: 1 or a 1: 2 ratio between shaft d and shaft C is possible. So these waves are arranged in series. However, shaft c drives shaft B and shaft A in parallel. With the help of bearing III, a 1: 1 and a 1: 2 ratio is possible between shaft c and shaft B. The gear ratios possible with the aid of this gear arrangement are briefly derived. The following applies: _ab = (n _b + n _c ) / 2

It applies depending on the setting of I: It applies depending on the setting of II: It applies depending on the setting of III:

Then the following applies for the eight possible setting variants:

Settings I Settings II Settings III Translate, na, b / nan

1 1 1 1: 1 2 1 1 1: 2

1 2 1 1: 2

2 2 1 1: 4

1 1 2 1: 1,333 2 1 2 1: 2,666 1 2 2 1: 2,666

2 2 2 1: 5,333

Claims

1. Gear with a mechanical target gear for positive, gear and rack-free motion conversion and a guide gear for determining the translation of the target gear (22 ... 26) with conversion of a rotating into a rotating movement or for defining the translation of the target gear (1 ... 5) with conversion of a linear into a linear movement, characterized in that the guide gear (6 ... 8; 20, 21) around an axis (9; 21) can be rotated and the transmission ratio of the target gear can be changed by this rotation.

2. Transmission according to claim 1, wherein the target gear converts a rotating pivot (rotation under 360 °) into a rotating pivot, characterized in that the ratio of the target gear is continuously variable by twisting the guide gear (20, 21) .

3. Transmission according to claim 1, in which the target transmission converts a finite linear movement into a finite linear movement, characterized in that the translation of the target transmission is infinitely variable by rotating the guide gear (6 ... 9).

4. Use of the transmission according to one of claims 1 to 3, for converting an output movement of a given constant length or given constant angle of rotation, in particular on pneumatic cylinders or pneumatic swivel motors, in target movements of different lengths or different swivel angles.

5. Transmission according to claim 4, characterized in that the one end point of the target movement is the same for all settings of the Füh¬ transmission.

6. Use of the transmission according to one of claims 1 to 3, for changing the steering ratio of vehicle steering on shafts rotatable by finite angles (steering shaft, steering spindle, etc.) or on parts displaceable by finite lengths (rack, etc.).

7. Transmission according to claim 1 with rotating orbital output and target movements, characterized in that two different ratios with the transmission ratio 1: 1 and 1: 2 of the target gear can be realized by rotating the guide gear (20, 21) .

8. Gear with rotating, rotating output and Zielbe¬ movements using at least two gears according to claim 7, characterized in that the two gears one behind the other (in series) or for switching the two input shafts of a three-shaft epicyclic gearbox with two input shafts and one output shaft (parallel) are used.

9. Gear according to one of claims 1 to 8, characterized gekenn¬ characterized in that the movements along the guide gear are fixed by roller bearings or linear roller guides.