DE10030321A1 - Adjustment mechanism to set one component against another has two toothed cogwheels and an input shaft with toothed splines and splined planet wheels for a simple adjustment action with precise positioning - Google Patents

Abstract

The mechanism for an adjustment setting between two components has at least one adjustment cogwheel (1) with a toothed zone (5) and a further cogwheel (2) with a toothed area (6). An input shaft (3) is toothed with splines (14), and at least two planetary cogwheels (10a-10d) have toothed splines (15,16). The teeth (1) of the first cogwheel (1) mesh with one set of planetary splines (15) and the other cogwheel teeth (6) mesh with the other set of planetary splines (16). The splines (14) of the input shaft (3) mesh either with the planetary splines (16) of each planet wheel (10a-1d) or the teeth of the first and second cogwheels. The tooth count at the teeth (5,6) of the two cogwheels (1,2) differ from each other and/or the planetary tooth splines (15,16) have different tooth counts.

Description

The invention relates to an adjusting device for adjusting a second part les compared to a first part, especially for adjusting articulated parts such as z. B. robot joint parts.

When adjusting a joint part compared to another joint part, esp special of joint parts on a robot arm, is in particular a good position Renewability and torque-resistant movement of the joint parts to one another are required. For this, u. a. Stepper motors are used that have an exact adjustability ensure the joint parts to each other, or z. B. Electric motors with a high Reduction.

When using motors such. B. electric motors, with higher speeds can achieve the required high gear reduction, for example through gearboxes with elasti schematic gear rim (harmonic drive gear) can be realized. With these ver positions or gearboxes are two internally toothed gears with different gears Number of teeth and an external ver provided in the internally toothed gears toothed, elastic gear provided which has an elliptical shape and  is deformed when turning so that its outer teeth successively into the tooth gap ken of the internally toothed gears are pressed in, creating a relative win angle adjustment is achieved in which the teeth of the externally toothed elastic Gear are constantly engaged with the internal gears. The difference in The number of teeth on the internally toothed gears is greater than or equal to 2.

To achieve large reductions, large numbers of teeth are necessary, for what highly elastic, expensive and friction materials are needed.

The invention is based, compared to the prior art Ver to create improvement and in particular to create an adjustment device that with relatively little effort, preferably small dimensions and less Dimensions, ensuring an accurate and permanent positionability. Here should preferably a firm clamping or self-blocking of the parts at a high Reduction and as little friction as possible can be guaranteed. The fiction moderate adjustment device should preferably with simple materials and with a simple and inexpensive manufacture can be realized.

This task is accomplished by an adjusting device for adjusting a first part solved against a second part, with two adjusting gears, each on egg Nem part are attachable and each have an internal toothing, an drive shaft, which is arranged concentrically to the adjusting gears and a Has external shaft teeth, and at least two, preferably four or more planet gears, each with at least two external gear areas, d. H. at least a first external tooth area and one in the axial direction device to this offset second external tooth area. in this connection the first external toothing areas are in engagement with the first internal toothing tion of the first adjusting gear and the second external toothing areas in Engagement with the second internal toothing of the second adjusting gear, and the External shaft toothing of the drive shaft is in engagement with one of the at least two external toothing areas. A relative adjustment of the adjustment gears to each other is ensured by the first internal toothing and the  second internal teeth have different numbers of teeth and / or he most external tooth areas of the planetary gears and the second external ver toothed areas of the planetary gears have different numbers of teeth.

According to the invention, a relative adjustment of the adjusting gears with internal ver serrations achieved by connecting them via common planet gears are driven by a drive shaft. The planet gears have areas axially separated from each other, one area of which each one of the two adjusting gears with internal teeth are engaged. By doing now the number of teeth of the internal toothing and / or the number of teeth of the axial separate external toothing or external toothing areas each of the planetary gear are different from each other, show that from the first inside toothing and the first outer toothing region formed first inside wheel pair system and that of the second internal toothing and the second outer toothing area formed second internal gear system different translations towards. Since on each of the planet gears a first external gear area and second external tooth area are rigidly coupled to each other, the Ver adjusting gears with internal toothing forced to rotate relative.

By the difference in the number of teeth of the internal gears or the outer toothing is selected to be relatively small in relation to the number of teeth with a larger rotational movement of the shaft due to the relatively small teeth difference in number a very small rotation of the internal gears to each other can be achieved, which leads to a high reduction. So can run fast de Low torque motors are used, due to the ho hen reduction a small, precisely positionable twist with a relatively high Torque can be achieved.

Thus, with few, inexpensive parts that can be manufactured (essentially teeth wheels with internal teeth or external teeth) a smooth, small ver Adjustment device can be realized with low mass, which is still robust, large Can transmit torques and ensure precise position adjustment,  clamps firmly in any position and has low friction. The adjustment device device is easy to assemble and easy to use.

Since according to the invention motors, in particular electric motors, with high speeds can also be used, an inexpensive robot joint can be realized be light, in which advantageously the motors and / or adjusting devices can be accommodated in the joint parts or robot arm parts. by virtue of the small mass of the adjustment device according to the invention and the small Mass of the usable, high-speed motors can robot joints with ge low mass, can be produced, which can carry larger loads with smaller robots can.

In that the first and second external toothing areas have the same number of teeth sen, can be high due to a difference in the number of teeth of the internal gears Reduction of the adjustment torque can be achieved. So the first and second External teeth of the planet gears in each case in the first or second In meshing, is at least one of the planet gears Angular misalignment between the two external toothing areas advantageous. To the To further increase position accuracy, it is advantageous to use a slant or something to use tapered teeth.

According to the invention, planetary gears can advantageously have three or more External gear areas are used. In this case, the first and second external toothing area respectively in engagement with the first and second in internal toothing of the corresponding adjusting gears, and a third external toothing range is in engagement with the external shaft gear acting as a sun gear. In this case too, the at least three external toothing areas are each Orbiting gear rigidly coupled together. They are preferably made up of three or more juxtaposed, joined together on axial surfaces gear wheels made. By using a third external gear range can be a desired gear ratio between the shaft and the planet gears are made because of this gear ratio  the number of teeth of the external shaft teeth and the third external toothing rich can be set without the number of teeth of the first and second external tooth areas. Thus, a ge Desired difference in the number of teeth of the internal gears or the first and second external tooth areas regardless of the setting of the over setting ratio between the shaft and planet gears.

The third external toothing area can advantageously be in the middle between the first and second external tooth areas. alternative For this purpose, at least two third external toothing areas can be provided the one that has the first external tooth area and the second external tooth range between them, so that a uniform absorption of the Drive torque from the drive shaft is possible. When using two third external gear areas are each with the external shaft gear engaged. For this purpose, the external shaft toothing can be placed in several offset be richly divided.

For the formation of a desired number of teeth ratio between the third External tooth area and the outer shaft toothing can be the third outer tooth area with a larger or smaller radius than the first and second external tooth areas are formed. Thus, another Be rich of desired reduction ratios of the Ver Actuator almost continuously by adjusting the number of teeth ratio se between external shaft gearing and third external gearing area, as well the number of teeth differences between the first internal toothing and the second In internal toothing and / or the first external toothing and second external toothing can be adjusted.

Due to the uneven load on the various external gears Torques arise perpendicular to the axes of the planet gears, which act in the direction of a tilt of the planet gears. Continue to work with high speeds of centrifugal force on the planet gears that these in the  Can press adjustment gears. To reduce these torques and centrifugal forces catch, it is advantageous to have the planet gears in a fixed cage or several to store solid cages. The cages capture the planet gears z. B. to the Axial surfaces.

Instead of cages, however, separate treads on the ar pitch diameters on the axial side areas of the planet gears and the adjusting gears are provided. These treads allow one radial support of the planet gears on the adjusting gears, whereby Ver tilts due to the uneven load and the radial centrifugal forces to be caught. The running surfaces roll against each other.

The planet gears can axially ver from two or three or more with each other bound single wheels are manufactured. The individual wheels can ver wedges, welded, glued or connected using screws. The Ver Setting gears can be designed as stamped sheet metal parts or pressed sheet metal parts.

By one of the internal gears is fixed to the housing and the other inside gear is connected to an output shaft, a gear with a high base be realized. When using planetary gears with the same teeth numbers and internal gears with different numbers of teeth can be a gear be realized without reversing the direction of rotation by using the adjusting gear the internal toothing is attached to the housing with a lower number of teeth, so that due to the relative rotation of the drive shaft to the housing of the second adjusting gear in relation to the housing with the same direction of rotation is effected.  

The invention will hereinafter be elucidated with reference to the accompanying drawings Forms of training explained. Show it:

Figure 1 is an exploded view of a Verstellvorrich device according to a first embodiment of the invention.

FIG. 2 shows the adjustment device from FIG. 1 in axial section and radial section;

Fig. 3 is an exploded view of an adjustment device according to a second embodiment of the invention;

FIG. 4a, b show a views of the second embodiment in an axial section respectively a perspective representation;

Fig. 5 is a radial section through the embodiment of Fig. 3;

Figure 6 is a schematic representation of an axial section of a Verstellvor direction according to a third embodiment of the invention.

Fig. 7 is a radial section and a perspective view of a joint part with an inventive device and an electric motor;

Fig. 8 is a block diagram of the embodiments of Figs. 3 to 6;

Fig. 9 shows another, modified from Fig. 3 embodiment.

According to Fig. 1 comprises an adjusting device according to voltage 6 to a first embodiment of a first shift gear 1 with a first inner toothing 5 and for this purpose offset in the axial direction of the second shift gear 2 with a second Innenverzah.

A drive shaft 3 with a len outer toothing 14 is arranged concentrically with the adjusting gears 1 , 2 . Around the axis turnaround gear wheels 10 a, 10b, 10c and 10d are arranged distributed. Each planetary gear 10 a to 10 d is each made of two individual gears 17 , 18 , which are connected to one another at their axial end faces, for. B. are glued, welded, screwed or wedged. They can also be connected to one another as injection molded parts. Thus, each assembled planetary gear 10 a to 10 d has two axially offset, in this embodiment, directly adjacent outer toothed areas. Here, the planet gears are arranged in such a way in the adjusting gears 1 , 2 that a first external tooth area 15 of each planet gear is in a grip with the first internal teeth 5 and thus an inner wheel pair is formed. Second outer toothing areas 16 of each planetary gear are in engagement with the second inner toothing 6 and thus form a second pair of inner wheels. The external shaft toothing 14 can be in engagement with either the first external toothing regions 15 or the second external toothing regions 16 .

According to the invention, either the number of teeth of the first external toothing regions 15 and the second external toothing regions 16 differ, and / or the number of teeth of the first internal toothing 5 and the second internal toothing 6 differ.

The individual gears 17 and 18 , which are each assembled to form a planetary gear 10 a to 10 d, have the same division of labor diameter. Thus, a coupling of the two pairs of inner wheels on the composite planet gears 10 a to 10 d is achieved, while the adjusting gears 1 , 2 are rotatable relative to each other bar.

In the embodiment shown in FIG. 1, the number of teeth of the first external toothing areas 15 and the second external toothing areas 16 differ. The outer shaft toothing 14 - which acts as a sun gear in the epicyclic gear, is in engagement with the second outer toothing regions 16 , which in turn are in engagement with the second inner toothing 6 .

Here, for. B. the outer shaft teeth 16 teeth, the first outer toothing areas 18 teeth and the second outer teeth areas each have 20 teeth. The internal teeth can have the same number of teeth, for. B. Z = 51. Furthermore, it is possible that the number of teeth of the first inner teeth 5 , 6 are unequal. Here, for. B. the number of teeth of the internal teeth 51 and the number of teeth of the second internal teeth 56 .

When the shaft 3 is actuated, the planet gears 10 a to d perform a movement in Umlaufbe in both adjusting gears, whereby a relative rotation of the adjusting gears is forced relative to one another due to the different number of teeth of the external toothing areas.

FIG. 2 shows the use of the adjusting device of the first embodiment in a housing 100 , the first adjusting gear 1 being formed as an output hollow shaft which extends to the left in FIG. 2. The second outer toothing areas 16 of the planet gears, which are in engagement with the shaft outer toothing 14 , are fixedly attached to the housing 100 via the second inner toothing 6 of the second adjusting gear 2 . Thus, the second adjusting gear acts as a housing-side fixation of the rotating operation, so that the Verstellvor device according to the invention acts as a reduction gear of the shaft 3 to the output shaft 1 .

The embodiment of FIGS. 1, 2 with two axially adjacent external toothing areas already enables a large number of possible reduction ratios by setting different numbers of teeth of the external toothing and / or internal toothing. In order to be able to set a reduction ratio even more precisely, third external toothing areas 60 are provided in the individual planetary gears according to the embodiment of FIG. 3. Thus, each revolving gear has three axially adjacent individual gears 17 a to 17 d, 61 a to 61 d and 18 a to 18 d. In Fig. 3, the planet gears are pulled apart for visualization in the axial direction, but in this embodiment as well as the embodiment of FIG. 1, they are actually rigidly coupled to one another, e.g. B. welded, glued, riveted, screwed or wedged or the planetary gears are made as one piece from injection molded parts.

In this embodiment, the shaft outer toothing 14 of the drive shaft 3 is in engagement with third outer toothing areas 60 , while the first outer toothing areas 15 are in turn in engagement with the first inner toothing 5 of the first adjusting gear 1 , and the second outer toothing areas 16 are again in engagement with the second inner toothing 6 of the second adjusting gear 2 .

As a result, a desired reduction ratio between the shaft 3 and the planetary gears can already be achieved, which is fixed by the number of teeth of the shafts external teeth 14 and the number of teeth of the external toothing areas 60 Festge. Due to the rigid coupling of the individual gears 17 , 61 and 18 , the rotary movement is transmitted to the entire orbital gears. Also in this embodiment, there is a relative adjustment of the adjusting gears 1 and 2 to one another by differences in the number of teeth of the first outer toothing regions 15 and second outer toothing regions 16 , and / or differences in the number of teeth of the first inner toothing 5 and second inner toothing 6 . Egg of the two adjusting gears, e.g. B. in turn the second adjusting gear 2 , z. B. be fixed to the housing, so that there is a reduction of the Drehbe movement of the drive shaft 3 to the first adjusting gear 1 . In this case, the reduction ratio achieved can be designed relatively freely, since the number of teeth of the third external toothing regions 60 can be selected independently of the number of teeth of the first external toothing regions 15 and second external toothing regions 16 .

As can be seen from FIG. 5, in the embodiments of FIGS. 3 to 5 shown here, the number of teeth of the first external toothing areas 15 and second external toothing areas 16 is again different, as already explained with reference to the first embodiment of FIGS. 1, 2. Alternatively or in addition, differences in the number of teeth of the internal gears 5 , 6 can be set.

In the embodiment of FIG. 3, a large number of teeth of the third outer been achieved toothed portions by the individual gears 61 a to 61 d has a size ren radius than the individual gears 17 a to 17 d and 16 a having d to 16. This can be seen in particular from FIG. 4. Alternatively, the Radi, according to Fig. 6 us of the third individual gears 161a to 61d also a formed smaller than the radius of the first individual gears 17-17 d and second individual gears 18 a to 18 d bisa, as shown in Fig. 6 can be seen. A variation of the radius of the third individual gears 161 a to 161 d thus enables a large number of adjustable tooth numbers of the third external toothing areas 60 . Referring to FIG. 6, a compact construction 18 can be achieved in the radial direction, since the external teeth 14 of the drive shaft 3 in the radial direction overlaps partially with the individual gears 17 a, a.

Fig. 7 shows an arrangement of an adjusting device according to the invention in a housing 100 , in which a small, fast-running electric motor 200 is arranged. By the second adjustment gear wheel 2 is rigidly coupled to the housing 100, a reduction of the high-speed drive shaft 3 to the drive shaft as Ab-acting first shift gear 1 can be effected. Accordingly, as an alternative to this embodiment, the first adjusting gear 1 can be fixed to the housing and the second adjusting gear 2 can be designed as an output shaft.

Fig. 8 shows a block diagram in which
z1 = number of teeth of the external shaft toothing (or the sun gear),
z2 = number of teeth of the third external tooth area,
z3 = number of teeth of the second external tooth area,
z4 = number of teeth of the second internal toothing,
z5 = number of teeth of the first external tooth area,
z6 = number of teeth of the first internal toothing.

Here, the second adjustment gear serves as a housing-fixed attachment, the first Adjusting gear as output Ab and the drive shaft as drive On. (From the pla netenrad can also be tapped off.) It results a Ratio i = (z6 × (1 + (z2 × z4) / (z1 × z3))) / (z6 - z5 × z4 / z3).  

In the embodiment without a third external toothing area, z2 = z3 or z2 = z5.
With Z1 = 54, z2 = z3 = z5 = 15, z4 = 84, Z6 = 86, i = 109.889.
With z1 = 15, z2 = z3 = z5 = 10, Z4 = 35, Z6 = 36, i = 120,
with z1 = 15, z2 = z3 = 10, Z4 = 35, z5 = 9, Z6 = 31, i = -206.667,
with z1 = 16, Z2 = Z3 = 20, Z4 = 56, z5 = 18, Z6 = 51, i = 382.5
with z1 = 16, z2 = Z3 = 18, Z4 = 52, z5 = 16, Z6 = 47, i = 256.821
with z1 = 14, z2 = 22, z3 = 20, z4 = 56, Z5 = 18, Z6 = 51, i = 459

In the embodiment of FIG. 9, compared to the embodiment of FIG. 3, treads 150 , 151 , 152 , 153 for a rolling movement of the planetary gears are axially to the side of the first and second external teeth 15 , 16 and axially to the side of the first and second internal teeth 5 , 6 trained in the adjustment gears. The treads 150 , 151 , 152 , 153 run in the individual gears each at ra dialer height of the division of labor diameter, so that they also roll on each other during the rolling motion of the planet gears. As a result, radial support of the planetary gears to the outside for intercepting centrifugal forces can be achieved in order to avoid excessive pressing of the first and second external gears into the first and second internal gears. Furthermore, the individual planet gears can be supported on the adjusting gears at axially offset locations, so that the planet gears are secured against tilting movements. In this way, in particular torques that arise on the planet gears due to the different loads of the first, second and third external toothings perpendicular to the axis can be absorbed or reduced. As an alternative to these treads, the planet gears can also be held in fixed cages and z. B. are supported on their axial end faces.

According to the invention, it is also possible to have more than three different external teeth areas to be placed side by side. In principle, more can be done here  be used as two adjusting gears, the z. B. optionally as output ge can be chosen.

The drive shaft can, as shown in the figures, as a rod shaft or as Be hollow shaft. In the last field there is a motor in the hollow shaft to be ordered.

Claims (23)

1. Adjustment device for adjusting a second part with respect to a first part, in particular a second joint part with respect to a first joint part
a z. B. on the first part attachable first adjusting gear ( 1 ) with a first internal toothing ( 5 ),
a z. B. attachable to the second part second adjusting gear ( 2 ) with egg ner second internal toothing ( 6 ),
a drive shaft ( 3 ) which is arranged concentrically with the first adjusting gear and the second adjusting gear and has a shaft outer toothing ( 14 ), and
at least two planetary gears ( 10 a-d), each having at least two axially offset external toothing areas ( 15 , 16 , 60 ),
wherein the first internal toothing ( 5 ) is in engagement with a first external toothing region ( 15 ) of each planetary gear and the second internal toothing ( 6 ) is in engagement with a second external toothing region ( 16 ) of each planetary gear, and the shaft external toothing is in engagement with one of the external toothing regions ( 16 , 60 ) of each planet gear,
wherein the first internal teeth ( 5 ) and the second internal teeth ( 6 ) have different numbers of teeth (n, nx) and / or the first external teeth ( 15 a-d) and the second external teeth ( 16 a-d) have different numbers of teeth (m). 2. Adjusting device according to claim 1, characterized in that the first internal teeth ( 5 ) and the second internal teeth ( 6 ) have different numbers of teeth (n, nx) and the first external teeth ( 15 a-d) and the second external teeth ( 16 ad) have the same number of teeth (m) have, at least in one planetary gear ( 10 b, c, d) the first external teeth ( 15 b, c, d) and the second external teeth ( 16 b, c, d) have an angular offset to one another. 3. Adjusting device according to claim 1 or 2, characterized in that one of the adjusting gears ( 1 ) is fixed to the housing and the other adjusting gear ( 2 ) is connected to an output shaft. 4. Adjusting device according to claim 2 and 3, characterized in that the adjusting gear with the lower number of teeth is fixed to the housing and the adjusting gear with the larger number of teeth on the output shaft brought. 5. Adjusting device according to one of claims 1 to 4, characterized in that the planet gears ( 10 a, b, c, d) each have at least three, preferably exactly three, axially offset outer toothing areas ( 15 , 16 , 60 ), wherein the external shaft gear ( 14 ) is in engagement with a third external gear region ( 60 ) of each planet gear. 6. Adjusting device according to claim 5, characterized in that the third external tooth area ( 60 ) has a larger or smaller number of teeth than the first external tooth area ( 15 ) and / or the second external tooth area ( 16 ). 7. Adjusting device according to claim 5 or 6, characterized in that the third external toothing area ( 60 ) between the first external toothing area ( 15 ) and the second external toothing area ( 16 ) of the order gears is arranged. 8. Adjusting device according to claim 5 or 5, characterized in that at least on a few orbital gears a plurality of third external gear teeth rich are provided. 9. Adjusting device according to claim 8, characterized in that the first and second external toothing areas ( 15 , 16 ) of the planetary gears are each provided between two third external toothing areas. 10. Adjusting device according to one of claims 1 to 9, characterized in that the planet gears ( 10 a-d) each consist of at least two or three axially connected, preferably keyed, welded or screwed, individual gears ( 17 , 18 , 61 ). 11. Adjusting device according to one of claims 1 to 10, characterized in that a drive gear ( 4 ) with the outer shaft teeth ( 14 ) is mounted concentrically on the drive shaft ( 13 ). 12. Adjusting device according to one of claims 1 to 11, characterized in that the number of teeth (n, n-1) of the internal toothing ( 5 , 6 ) and the number of teeth (m) of the first and second external toothing areas (15a-d, 16a d) stand in a ratio of 3: 1 to 12: 1, preferably 5: 1 to 8: 1. 13. Adjusting device according to one of claims 1 to 12, characterized in that the first internal toothing ( 5 ) and the second internal toothing ( 6 ) have the same working pitch diameter and the first toothing ( 15 a-d) and the second external toothing ( 16 ad) have the same working division diameter. 14. Adjusting device according to one of claims 1 to 13, characterized in that the drive shaft ( 3 ) is designed as a rod shaft or hollow shaft. 15. Adjusting device according to one of claims 1 to 14, characterized in that treads ( 150 , 151 , 152 , 153 ) are provided for a rolling movement on the planet gears and the first and / or second adjusting gear. 16. joint, in particular robot joint, with at least three joint parts, wherein a second hinge part via a first adjustment device according to one of the An say ver 1 to 15 compared to a first hinge part about a first axis is rotatable and a third joint part relative to the second joint part a second adjustment device according to any one of claims 1 to 15 second axis different from the first axis can be rotated. 17. Joint according to claim 16, characterized in that the second axis is rotated with respect to the first axis, preferably perpendicular to this runs.   18. Joint according to claim 16 or 17, characterized in that the first Articulated part and the second articulated part each with an adjustment gear which he Most adjustment device is connected and / or the second joint part and the third joint part each with an adjustment gear of the second adjustment direction is connected. 19. Joint according to one of claims 16 to 18, characterized in that in the first joint, a first drive motor for rotating the second Joint part is arranged opposite the first joint part. 20. Joint according to one of claims 16 to 19, characterized in that in the second joint part, a second drive motor for rotating the third th joint part is arranged opposite the second joint part. 21. Joint according to one of claims 16 to 20, characterized in that the second hinge part and the third hinge part via the second adjustment device device and a third adjusting device according to one of claims 1 to 7 are rotatably connected. 22. Joint according to one of claims 16 to 21, characterized in that the first adjusting device in the first joint part and / or the second ver adjusting device and possibly the third adjusting device in the two th joint part are arranged. 23. Joint according to one of claims 16 to 22, characterized in that the adjustment gears are connected via a four-point bearing.