JPS6119397B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a play-free swivel drive for swivelingly mounted components of machines, devices, manipulators and the like, which comprises a torsionally resilient drive shaft; Two drive pinions at a distance from one another are arranged preloaded with respect to each other, each drive pinion being assigned a reduction gear, each reduction gear being connected to the drive shaft. The invention relates to a type having a driven wheel coaxially supported thereon and connected to said component.

In known types of manipulators, so-called mechanical hands operate as precisely as possible in three dimensions within a large spatial area to carry out a predetermined task at a preprogrammed spatial point. is important. In this case, the basic frame is equipped with a turntable that can be rotated around a vertical axis.
A drive arm pivotable about a horizontal axis is supported on this rotary table, and this drive arm itself carries a jib, which is also supported about a horizontal axis; A mechanical hand is also provided which can rotate or pivot in multiple dimensions. With a structure as described above, any spatial point within the maximum swivel range of the swivel axis can be automatically controlled.

In the above-mentioned prior art, each of the pivot shafts of the manipulator is provided with its own drive device. In order to make use of the optimal torque of the drive motor, it is then necessary to significantly reduce the drive speed using a suitable transmission.

In this case, it has proven advantageous to connect the individual drive wheels of the reduction gear to the part to be driven coaxially with respect to the pivot axis of this part.

However, manipulators are only effective in practical use if they can be manipulated with great precision towards a defined target point. In known manipulators, the play provided in the transmission used is significantly increased due to the large length range of the jib, so that the mechanical hand cannot cope with this transmission ratio. Since the target object is reached within the specified variation range, the above conditions cannot be completely satisfied. In particular, if the driven part has to move rotationally and vibrably, possibly even beyond the dead center of its swiveling position,
The operational inaccuracy described above becomes significant.

It is therefore an object of the present invention to improve the construction of a swivel drive, for example in a manipulator, in such a way that the play normally provided in the reduction gear does not influence the accuracy of the operation of the mechanical hand. It is. Moreover, there is a need for more precise targeting of mechanical hands without significantly increasing construction costs. This problem is not limited only to the movement of the mechanical parts of the manipulator, but it is also important to target and precisely manipulate the activated mechanical parts, as is the case, for example, in hoists or weapons technology. This also applies to other machines. However, the gist of the present invention can be particularly clearly explained using a manipulator as an example.

Departing from the prior art mentioned at the outset, it is a feature of the invention that, in the drive of the pivotable or rotary-oscillatory movable component, the two driven vehicles are arranged in such a way as to eliminate overall transmission play. It is possible to tension the drive shaft until the desired torsionally elastic prestress is created, and in the tensioned position it is fixed or supported on the component to be driven.

According to the invention, the bifurcation of the transmission system and the play within it are taken into account, both transmission systems being provided with a torsionally elastic prestress relative to and opposite the driven machine part. By virtue of the suspension, this play is eliminated and a more precise movement of the individual machine parts is therefore possible. Due to the fixed connection between the driven vehicle and the actuated machine part, the torsionally elastic prestress of this transmission system can be maintained in the actuated machine part. On the other hand, this prestress in the deformation of the drive shaft causes the two drive pinions of the drive shaft to rest without play on the transmission elements associated with the drive shaft in either direction of rotation.

It is already known to eliminate transmission play in rotary drives by means of torsionally elastic deformations of the shaft in the transmission or driven range (Magazine "Metall" 23/1969, 12, 1289-- 1295 and Austrian Patent No. 189-469) However, this known construction does not solve the above-mentioned problem, since only a small part of the total transmission play (Austrian Patent No. 189-469) or 2
This is because the play in the two transmission systems is only compensated for differently (see "Metall"). It is impossible to apply the above-mentioned known structure to the swing drive device of the present invention, since neither the necessary deceleration amount nor the coaxiality of the driving and driven shafts can be obtained.

Advantageous embodiments of the invention are defined in the second patent claim.
As described in items 7 to 7.

The invention will now be explained with reference to the illustrated embodiment.

In FIG. 1, a manipulator is illustrated in order to specify the number and position of the axes of the individual driven members to which the arrangement of the invention can be advantageously applied.

A so-called rotary table 2 is supported on a base frame 1 fixed to the floor so as to be pivotable about a vertical pivot axis 3. This rotary table 2 is rotated about a pivot axis 3 by a drive motor 4, and the direction of rotation can be changed. A drive arm 5 is mounted on the rotary table 2 in such a way that it can pivot in a rotary oscillatory manner on a pivot axis 6 , the pivoting movement of the drive arm 5 being produced by a motor 7 . The pivot axis 6 is horizontal. The weight of the drive arm 5 and the weight of the components arranged thereon are balanced out by a schematically illustrated balance weight 8.

A jib 9 is supported at the free end of the drive arm 5 about a pivot axis 10 . The pivoting movement of the jib 9 is produced by a drive motor 11.
This pivoting arm 9 projects significantly laterally and holds at its free end a so-called magic hand 13, which can be equipped with a tool of any desired shape. For example, this hand 13 is the jib axis 12
It is provided so that it can rotate reciprocally around the center. In the embodiment shown in FIG. 1, this hand 13 is the corner member 1.
5 and a holding arm 17 connected to the corner member.
and a connecting member 18, by means of which rotational movement about the jib axis 12 and the pivot axes 16 and 19 takes place.

As is most clearly illustrated in the case of the pivot axis 10, the transmission play provided in this part to enable the movement of the jib 9 is transmitted to the area of the hand 13 in a significantly increased manner, thereby This leads to mechanical inaccuracies in known manipulators.

If the above transmission play can be eliminated, the accuracy of operation of the hand 13 will gradually improve.
This problem is the same not only in the jib 9 but also in many other pivot axes. Furthermore, this problem is not limited to manipulators. For example, as is known, there are rack and pinion drives in which the rack is pressed against the teeth of a pinion by a hydraulic cylinder, in which case the magnitude of the speed change is naturally limited. Subsequently, embodiments of the present invention for eliminating the above-mentioned transmission play and enabling more accurate operation of the actuated parts are shown in the drawings.

The example in FIG. 2 shows a sectional view through the pivot axis 10, on which the jib 9 is supported. By means of the drive motor 11, via a play-free transmission 23, for example a toothed V-belt arrangement,
A drive shaft 24 made of a material having torsional elasticity is driven. Drive pinions 25 and 26 are provided at both ends of the drive shaft 24.
5 and 26 branch the rotational moment of the drive shaft 24 and transmit it to the driven wheels 29 and 30 via the reduction gears 27 and 28 (schematically shown), and the driven wheels 29 and 30 are connected to the jib 9. is fixedly coupled to. The reduction gears 27, 28 may be of any type, such as a planetary gear or a cyclo transmission (rolling gear). If the driven wheels 29, 30 are rigidly and immovably connected to the jib 9, the transmission play becomes completely effective. However, in the exemplary embodiment shown, at least one of the driven wheels 29, 30 is torsionally tensioned against the jib 9. For this purpose, the corresponding driven wheels 29, 30 are rotatably arranged in the jib 9 and provided with a rotation stop, by means of which play in the transmission can be eliminated. It is advantageous to do so. In the example of FIG. 2, a clamping member 31 is shown schematically which serves to produce the tensioning effect described above. This clamping element 31 can be of different types.

An example of a variation of the above-mentioned tightening member is shown in FIG.
A lateral groove 33 is provided on the end surface of the bosses 32 of 9 and 30, a locking member 34 is engaged in the lateral groove 33, and both ends of the locking member protrude from the boss 32. A clamping screw 36 is positioned against the projecting end of this locking member 34, which clamping screw 36 is inserted into the jib 9 through a threaded sleeve 35.
and is held in a predetermined adjusted position by a mating nut 37. By appropriately tightening the tightening screws 36, the individual driven wheels 29,
30 can be rotated about its axis until the play in the transmission system of FIG. 2 is removed. As the boss 32 rotates, a torsional elastic load is applied to the drive shaft 24 shown in FIG. 2. As a result of this, both drive pinions 25, 26 arranged on the drive shaft 24 are brought into contact to the same degree with the associated parts of the reduction gears 27, 28, so that the jib 9 is aligned with the axis. It becomes possible to turn around 10 without any play.

It is clear that the clamping elements described above may also be designed differently, so that the invention is not limited to the illustrated embodiment.

The above-mentioned bearing and transmission types are applicable to all axes of the manipulator according to the invention, and also to the mechanical hand 13 having its parts driven by drive motors 20, 21, 22 of FIG. It can also be applied to small axes.

Regarding the type of support, the driven wheels 29, 30 are guided on the one hand by their tensioning action into the bore of the jib 9, and on the other hand are supported on the drive arm 5 via suitable bearing elements, so that Driven vehicle 2
It is significant that 9,30 performs dual functions at a very low cost. There is therefore no need for the jib 9 to be guided directly by an expensive bearing on the drive arm 5 which actually holds it.

It is clear that the arrangement according to FIGS. 2 and 3 with respect to the pivot axis 10 of FIG. 1 cannot be directly applied to the support of the pivot axis 3 of FIG. For this purpose, FIG. 4 shows a modified embodiment which corresponds essentially to the lower part of FIG. In this example, the vertical axis 3 of the turntable 2 is guided in the base frame 1 so as to be pivotable in both directions. The rotary table 2 is driven by the drive motor 2 via a play-free transmission 40, which can also be constructed as a toothed V-belt arrangement.

The part supported in the basic frame 1 is, for example, a flange 39 that is rotatably guided in a bearing 38 . The turntable 2 or other machine parts are fixedly connected to this flange 39. The flange 39 is of fork-like construction in the example of FIG. 4, thereby forming a bent web 44;
The driven vehicles 43, 43a are tensioned relative to each other via this web 44. Reduction transmissions 42, 42a and driven wheels 43, 43a attached thereto are installed on the sides of the bent web 44 and flange 39. The torsionally resilient clamping member is shown as locking member 34. The important point is that one transmission system is torsionally elastically tensioned with respect to the other transmission system, and this tensioning element is supported on the flange 39, so that the drive system 4, 40, 41
This is because it is guaranteed that no play will occur between the drive system 43 and the drive system 43, 39.

Based on this variant, it is ensured that a certain reduction gear has no play with respect to the driven part,
In addition, various constructional embodiments are possible with the aim of making its operation sufficiently precise, even if the position of its driven part is unstable or neutral, for example.

FIG. 5 shows a variant of the example in FIG.
7 and the transmission system 26, 28, so that the transmission 23 drives a neutral section of the drive shaft 24. Advantageously, the torsional action of the drive shaft 24 is not impaired at all, but only slightly. However, in this case as well, the spring-elastic length of the drive shaft 24 remains the same. The geometrical central part in this case means the point where one torsional preload transitions into the other torsional preload directed in the opposite direction. Due to the different set dimensions, the geometrical center defined in the invention may not correspond to the center shown between the two transmission systems in the drawing.

In one direction of rotation, a drive moment is superimposed on the preload of one half of the drive shaft 24 . The other half, which does not take part in the transmission of this rotational moment, is, on the contrary, partially relaxed, retaining a residual preload sufficient to prevent play;
This reduces friction. When the rotational direction is changed, the preloaded drive shaft 24 first returns to its initial preloaded state while maintaining the play compensation function, and then the superimposition of preload in the opposite direction due to the rotational direction change begins. . The method described above provides the same torsional stress or superimposed effect in both directions of rotation. As a result, various differences in individual vibrations and vibration characteristics do not occur when changing the direction of rotation.

FIG. 6 shows an example in which the drive device (transmission device 40) can act on the geometrical center of the torsionally elastic drive shaft device 41 even if it is located outside the transmission systems 42, 42a. has been done. In this case, the drive shaft arrangement 41 is formed from several parts. That is, one side of this drive shaft 41 is designed as a hollow shaft 45 through which a drive shaft 46 is connected to the hollow shaft 45 via a spline connection 47 in the geometrical central region. is engaged. The end of the further extending shaft section 51 of the drive shaft 46 is likewise connected via a spline connection 52 to a drive pinion 53 of the transmission system 42 . The hollow shaft 45 and the drive pinion 54 may also form one component. What is important in this configuration is the hollow shaft 45
The purpose is to make the torsional elasticity of the shaft portion 51 and the shaft portion 51 approximately the same, which is easily possible by forming a calculable cross section. The bearing 55 mainly functions while being supported on the drive shaft 46, allowing the hollow shaft 45 to undergo torsional elastic deformation relative to the drive shaft 46.

FIG. 7 shows yet another modification of the example shown in FIG.
Or located outside 26, 28. Drive shaft 2
4 is divided into two hollow shafts 56 and 57 of approximately the same length. A drive shaft 58 extends on one side and reaches the geometrical center of the transmission systems 25, 27 and 26, 28, where it connects via a spline connection 59 to the two inner ends of the hollow shafts 56, 57. The parts are combined. Bearing 60 has the same function as bearing 55 in FIG. Drive pinion 25, 26
together with the hollow shafts 56, 57 associated therewith may form a component. In this case as well, the important point is to make the torsional elasticity of the hollow shafts 56 and 57 the same.

Of course, the configuration possibilities according to the present invention are not limited to the above-mentioned embodiments. For example, the variants can be combined with each other by using drive units suitable for the respective design for the individual pivot axes.

[Brief explanation of the drawing]

The drawings show a plurality of embodiments of the present invention, in which Fig. 1 is a side view of the manipulator, Fig. 2 is a sectional view of the hinge portion of the manipulator seen in the direction of arrow A in Fig. 1, and Fig. 3 is a side view of the manipulator. 2 is a cross-sectional view along the line - -, FIG. 4 is a vertical sectional view of the basic frame of a manipulator with a variant embodiment of the swivel drive according to the invention, and FIG. 5 is according to FIG. Embodiment of variation of the drive device, FIG. 6 is a sectional view of a torsionally elastic drive shaft in a variation from FIG. 4, and FIG.
FIG. 3 is a sectional view of a torsionally elastic drive shaft in a variant of the figure; 1... Foundation frame, 2... Rotating table, 3... Vertical rotation axis, 4, 7, 11, 20, 21, 22
... Drive motor, 5 ... Drive arm, 6, 10,
16, 19... Rotating axis line, 8... Balance weight, 9... Jib, 12... Jib axis line, 13... Hand, 15... Corner member, 17... Holding arm, 18... Connection member, 23, 40... Transmission device, 24, 46, 58... Drive shaft, 25, 26,
53, 54... Drive pinion, 27, 28, 4
2, 42a... Reduction transmission device, 29, 30, 4
3, 43a... Driven vehicle, 31... Tightening member,
32... Boss, 33... Horizontal groove, 34... Locking member, 35... Threaded sleeve, 36... Tightening screw, 37... Compatible nut, 38, 55, 60...
... bearing, 39 ... flange, 41 ... drive shaft device, 44 ... bending web, 45, 56, 57 ...
Hollow shaft, 47, 52, 59... Spline joint portion, 51... Shaft portion.

Claims (1)

Claims: 1. A swiveling drive without play for swivelingly mounted components of machines, devices, manipulators and the like, on a torsionally elastic drive shaft 24, 41; distanced from each other 2
Two drive pinions 25, 26 are arranged prestressed with respect to each other, each drive pinion 25, 26 having one reduction gear 2 in each case.
7, 28 are assigned, each reduction gear 27, 28 having a driven wheel 29, 30 coaxially supported on the drive shaft 24, 41 and connected to the component. In the drive of the pivotable or rotary-oscillatory movable component, the two driven wheels 29, 30 are provided with the desired drive shaft 24 in order to eliminate overall transmission play. For a pivotably mounted machine part, characterized in that it can be tensioned until a torsionally elastic prestress is created, and in the tensioned position it is fixed or supported on the component 9 to be driven. swing drive device. 2. The individual driven wheels 29, 30 are rotatably arranged in the machine part 9 to be driven and the clamping member 31 is supported on the machine part 9.
2. A swing drive according to claim 1, wherein said part 9 can be non-rotatably loaded by a swivel drive. 3. A groove 33 is provided in the boss 32 of the driven wheels 29, 30, which extends perpendicularly and at a distance from the axis 10 of the driven wheels 29, 30, and in this groove 33, grooves 33 are provided on both sides. A protruding locking member 34 is engaged, and 2
3. A swing drive according to claim 2, in which two tightening adjustment screws act. 4. Claims in which the drive element acts directly or via the transmission 23 on the geometric center of the torsionally elastic drive shaft 24 between the two transmission systems 25, 27 or 26, 28 The swing drive device according to item 1. 5. The driving shafts 24, 41 are formed by being divided within a geometric center range, and the divided parts are connected to each other in a non-rotatable manner within this range. swing drive device. 6. At least one side of the drive shaft 41 is formed as a hollow shaft 45, and a drive shaft 46, which is unrotatably coupled to the hollow shaft 45 within the geometric center area, passes through the hollow shaft 45. A swing drive device according to claim 5, which comprises: 7 Both parts 45, 51 of drive shaft 24, 41,
6. The swing drive device according to claim 5, wherein the swing drive device 56 and 57 have cross-sectional shapes defined so as to form the same torsional elasticity.