Drive module for a cycloid drive, and directly driven cycloid disc

Abstract

The invention relates to a drive module (1) for a cycloid drive, having: a cycloid disc (10) which can wobble eccentrically about a central axis and has a cycloid profile (25) on the edge of the cycloid disc, said profile being in engagement with an outer support (40) at a location; a central opening (6); at least three bearing holes (5); an inner support comprising at least three webs (8), wherein the bearing holes (5) receive the at least three webs (8) and couple the cycloid disc (10) to the inner support; and a direct drive which is designed to act magnetically on the cycloid disc (10) such that the cycloid disc (10) interacts with a magnetic field of the direct drive and is brought into a wobbling motion in a translational manner via the magnetic field. The output process of the drive module (1) is carried out via the outer or inner support.

Description

[0001] Description

[0002] Drive module for a cycloid drive and directly driven cycloid disk

[0003] The present invention relates to a drive module for a cycloid drive and a cycloid drive, in particular for a multi-axis machine and / or a robot.

[0004] Cycloidal drives, also known as cycloidal gears or eccentric gears, typically have an eccentric disc or eccentric with which a cycloidal disc is moved. The eccentric disc is usually rotated via a shaft by an external motor or drive. Cycloidal drives are typically used to achieve lower speeds than the drive in order to provide high torques at the output and are therefore used where low speeds but high torques are to be transmitted. The advantage of cycloidal drives is that they can be subjected to a shock load many times the nominal torque, and their smaller installation space can be advantageous compared to other types of gears.

[0005] Conventional cycloidal drives comprise a cycloidal disk or wobble disk that can wobble eccentrically around a central axis, but is not freely rotatable. A point on the disk executes a small circular path compared to its diameter without any rotation of its own. This wobble disk, with its external toothing, for example with a wave-shaped profile, engages with an internal toothing of an outer ring, which is designed to fit exactly inversely. The cycloidal disk usually has fewer teeth, in particular wave crests, than there are teeth, in particular rounded pins, on the outer ring. In order to prevent the cycloidal disk from self-rotating, which is inevitable due to the engagement with the external toothing, it is provided with N bores on a radius within the disk, into which pins or webs of smaller diameter project. These pins or webs are installed on a support ring, i.e.that the cycloid disc is mounted relative to the support ring in their common plane around these pins or webs, whereby the support ring remains in the central axis.

[0006] The object of the present invention is to improve a drive module for a cycloidal drive, in particular a cycloidal drive, in particular to make this drive module more compact, and in particular without a rotating shaft which has to rotate faster than the output with the transmission ratio of the drive module.

[0007] This object is achieved by a drive module having the features of claim 1. Claim 11 protects a method, and claims 12 and 13 protect a system, computer program, or computer program product for implementing a method described herein. The subclaims relate to advantageous developments.

[0008] According to one embodiment of the invention, a drive module, in particular for a cycloid drive, has a cycloid disk, also known as a cam disk or swash plate. In one embodiment, the cycloid disk has a cycloid profile that meshes with an external support. Furthermore, in one embodiment, the cycloid disk has a central opening, in particular an opening that is formed concentrically with the cycloid disk. In one embodiment, the cycloid disk has at least two bearing holes, in particular bearing holes, which are arranged on a circular path concentric with the cycloid disk, in particular a circle concentric with the cycloid disk. In one embodiment, the bearing holes are distributed evenly, in particular over the circle, or are at least substantially equally spaced from one another.

[0009] According to one embodiment of the present invention, the drive module has an inner support with at least three webs, wherein the webs are designed such that they are or can be received by the bearing holes and allow a rotational movement required for the cycloidal movement of the cycloid disk. In particular, the bearing holes and the webs are designed such that the cycloid disk, with the bearing holes and the webs, can or does execute a cycloidal or wobbling movement. In one embodiment with the bearing holes, the cycloid disk is coupled to the inner support via the webs or can be coupled to it via the webs.

[0010] According to one embodiment of the invention, the drive module has a direct drive, wherein the direct drive is configured to act magnetically on the cycloidal disk. In one embodiment, the cycloidal disk interacts with the magnetic field of the direct drive and is deflected or rotated, in particular eccentrically, by this interaction. In one embodiment, at least one part of the cycloidal disk, in particular the (primarily) inner part permeated by the magnetic flux, consists of a, preferably particularly, suitable magnetic material.

[0011] Advantageously, the drive module, in particular the combination of drive and cycloidal gear, can thereby be constructed significantly more compactly, in particular the required installation space can be reduced or made smaller, wherein in one embodiment the masses and / or mass inertias are advantageously reduced.

[0012] According to one embodiment, the direct drive has a pole shoe ring with pole shoes, wherein the pole shoe ring is arranged in the opening of the cycloidal disc, in particular on a central axis of the drive module. In one embodiment, the pole shoe ring forms an air gap with the opening of the cycloidal disc, so that, in particular, an eccentric movement of the cycloidal disc about the central axis is enabled or possible. According to one embodiment, the pole shoes are oriented radially outward toward the cycloidal disc. "Radial" is preferably understood here as perpendicular to the central axis.

[0013] According to one embodiment, the direct drive comprises a pole shoe ring with pole shoe pairs that form a north pole and a south pole, particularly in the axial direction. This can, in one embodiment, enable the effect of the direct drive to be enhanced.

[0014] According to one embodiment, the direct drive comprises a pole shoe ring with pole shoes, wherein the pole shoe ring is arranged outside the cycloidal disc, in particular (radially) outside the outer support. In a further development, the direct drive comprises a pole shoe ring in (inside) the opening of the cycloidal disc and a pole shoe ring (radially) outside the cycloidal disc, in particular (radially) outside the outer support. In one embodiment, the pole shoe ring comprises at least 6, in particular at least 10 or at least 20, and / or at most 200 pole shoes, in particular at most 120 or at most 60.

[0015] According to one embodiment, the pole shoe ring has a central opening, in particular a passage, in particular a rigid central opening or passage. In one embodiment, this can be designed as a hollow shaft that extends through the assembly of the drive module, in particular through the entire assembly, in particular without impairing the function of the drive module. In one embodiment, the central opening is arranged coaxially with the pole shoe ring; in one embodiment, the center of the opening lies on the central axis.

[0016] In one embodiment, this advantageously makes it possible for cabling to be or is laid through the drive module, in particular through the central opening or feedthrough. Furthermore, in one embodiment, this makes it possible to achieve a design with fewer disruptive contours and / or a more aesthetic design, in particular because components and / or cabling do not have to be relocated outwards through the opening or feedthrough, in particular in the case of multi-axis machines and / or robots with sequential axes in particular, but can be accommodated in the opening or feedthrough in a more aesthetic way and / or passed through it. In one embodiment, relocating masses “inwards” advantageously makes it possible to achieve lower moments of inertia. Especially in the field of collaborative robots, which are also known as cobots, a more aesthetic appearance orDesign advantageous for a more direct interaction between a user and the robot. In one embodiment, this can make it possible for the surfaces of the robot, which is equipped with or comprises a drive module described herein, to be designed to be smoother, in particular without bulges, in particular if the drive module is used in a cobot. "Robot" and examples with robots are to be understood herein without restriction of generality. According to one embodiment, the drive module does not comprise an eccentric, in particular the cycloid disk of the drive module is not moved via an eccentric or an eccentric disk. Advantageously, this allows the drive module to be constructed in a simpler, in particular more compact, embodiment.

[0017] According to one embodiment, the drive module has no permanent magnets; in particular, the actuation has no permanent magnets, so that it is based in particular on reluctance. In one embodiment, this allows a more cost-effective^, in particular material-saving drive module to be built, in particular without the use of rare earth magnets. Furthermore, in one embodiment, weight can be saved, in particular by eliminating the (relatively heavy) permanent magnets. By eliminating the need for permanent magnets, in one embodiment, no back EMF (electromotive force) is advantageously generated, which would in particular result in a maximum speed dependent on the operating voltage. In one embodiment, the direct drive is (thus) a synchronous reluctance motor.

[0018] Furthermore, according to one embodiment, the electromagnets of the direct drive are fixed, in particular with respect to a housing of the drive module. Advantageously, according to one embodiment, the moment of inertia is small(er), in particular, it is determined (only) by the center of mass of the cycloidal disk orbiting the wobble radius (as a pure translational amount of its mass, in particular not as a moment of inertia during rotation) and a load on the output. In one embodiment, this makes it possible for the drive module to have a lower moment of inertia, in particular a much lower one, compared to a drive module that is actuated by an electric motor via an eccentric.

[0019] According to one embodiment, the drive module has means for determining a position, in particular at least one sensor, in particular at least one sensor for determining a position of the cycloidal disk and / or the output. In one embodiment, the at least one sensor is a Hall sensor, two xy sensors, a rotatable web with a position or rotation sensor, and / or the like. This advantageously allows, in particular in combination with a controller or means for controlling the electromagnets, a more accurate, in particular more precise, positioning of the drive module to be achieved, in particular carried out. In one embodiment, a drive module can thereby advantageously be used in a preferably shock-resistant actuator for a multi-axis machine, in particular a robot.

[0020] According to one embodiment, the cycloidal disk has an extension, in particular a projection, which is ring-shaped on the radially inner side of the cycloidal disk. In one embodiment, the extension can be designed as a single piece with the cycloidal disk or in another embodiment as two or more parts, in particular connected to the cycloidal disk by a positive, non-positive and / or materially bonded connection. Furthermore, in a further development, the extension is designed as a single piece or in multiple pieces, in particular as a ring-shaped portion, furthermore in particular as a ring-segment portion. In one embodiment, the pole shoes of the pole shoe ring are bipolar and in particular have a magnetic north pole and a magnetic south pole, in particular when the electromagnets are activated.In one embodiment, a pole shoe is split in two, in particular configured such that it forms a north pole and a south pole at a radial end in the direction of the central axis. In particular, the pole shoe ring has pole shoe pairs that are arranged in pairs such that a first pole shoe and a second pole shoe of the pole shoe pair are arranged next to one another in the axial direction (in the direction of the central axis). In one embodiment, the extension is configured such that it fits into an existing space between the pole shoe pairs or the plurality of pole shoes, in particular in a design with pole shoe pairs or a plurality of pole shoes arranged in the axial direction. In one embodiment, this advantageously makes it possible for the effect of the electromagnets, in particular that of reluctance minimization, to be greater than in particular without the extension.

[0021] According to one embodiment, the cycloidal disk has more than one extension, in particular at least two extensions. Accordingly, in one embodiment, the pole shoe ring has a plurality of pole shoes in the axial direction, which are arranged alternately with the at least two extensions or in pairs between the at least two extensions. Advantageously, this makes it possible in one embodiment for the effect on the cycloidal disk to be increased by the extension(s), in particular compared to a cycloidal disk that has only one extension, or only one (radially) inner or only one (radially) outer pole shoe ring.

[0022] In one embodiment, the extension of the cycloidal disk can enclose the pole piece at least substantially on both sides. In other words, the extension can be designed in one embodiment such that the pole piece is enclosed at least substantially on both sides. Advantageously, in one embodiment, this can enable the effect of the interaction between the cycloidal disk and the magnetic field to be enhanced, or even greater, than would be the case without the extension.

[0023] In one embodiment, the drive module has at least one, in particular at least two or at least three, and / or at most five cycloid disks. In one embodiment, each of the cycloid disks provided has a direct drive, in particular a pole shoe ring. In a further development, the cycloid disks are arranged such that an overall center of gravity of the cycloid disks provided is or remains stationary during a wobbling movement. In one embodiment, the phase of the cycloid disks is shifted from one another by 180°, in particular with two cycloid disks, or by 120°, in particular with three cycloid disks. In one embodiment, the phase shift is 3607N, where N is the number of cycloid disks provided.Advantageously, in one embodiment, this makes it possible for the drive module to be low-vibration / less vibration-prone than, in particular, one or more cycloid disks which have a center of mass of the cycloid disks which moves during the wobbling movement of the cycloid disk(s), in particular a center of mass which is not stationary.

[0024] In one embodiment, the existing, in particular the at least two or at least three, and / or at most five, cycloid disks have different thicknesses in the axial direction (in the direction of the central axis), in particular such that an overall center of mass of the cycloid disks lies on the central axis. Advantageously, in one embodiment, this can enable the drive module to be less subject to vibration. According to one embodiment of the invention, a cycloid drive comprises at least one drive module as described herein. In one embodiment, as already described herein, this can reduce a moment of inertia of the drive, in particular enable powerful or more powerful robots, and preferably contribute to improving the aesthetics and / or reducing the interfering contours of a robot. Advantageously, according to one embodiment, the cycloid drive is(are) smaller, in particular designed with fewer mechanically stressed parts or assemblies.

[0025] According to one embodiment of the invention, a method is provided for controlling a drive module for a cycloidal drive, in particular a drive module described herein. In one embodiment, the method comprises determining a position of the cycloidal disk. Alternatively or additionally, the method comprises determining the position of an output of the drive module. Furthermore, in one embodiment, the method comprises controlling, in particular commutating, the at least one electromagnet of at least one of the pole shoes, in particular controlling at least three electromagnets of at least three pole shoes, in particular such that the cycloidal disk of the drive module is positioned and / or moved, based on the determined position of the cycloidal disk and / or the determined position of the output. The controlling of the electromagnets, ortheir commutation, is in one embodiment in particular only carried out on the basis of a position if this has been determined, otherwise the control is carried out on the basis of the position that has been determined, "determined" as used herein is preferably to be understood as "if determined". In one embodiment, the control causes the cycloid disk to adjust an air gap in such a way that a "wobbling" or "tumbling" movement of the cycloid disk about the central axis is induced, in particular by the control. Advantageously, this can in one embodiment enable the cycloid disk to be precisely positioned and / or moved or is moved. In one embodiment, this can enable a(n) more precise control of the drive module, in particular in comparison with an eccentric-controlled drive module.

[0026] Furthermore, in one embodiment of the invention, a system is provided for operating and / or monitoring a drive module for a cycloid drive, in particular a cycloid drive for a multi-axis machine, which is configured to carry out a method as described in particular herein. In one embodiment, the system is configured to operate and / or monitor a plurality of drive modules. In one embodiment, the system comprises means for determining a position, in particular of the cycloid disk and / or the output of the drive module. Furthermore, in one embodiment, the system comprises means for controlling the at least one electromagnet, in particular means for controlling at least three electromagnets, in particular for deflecting the cycloid disk, further in particular for inducing a wobbling movement of the cycloid disk about the central axis.

[0027] Advantageously, in one embodiment, this makes it possible for the system to be controlled more accurately and / or precisely, in particular to be moved, in particular by means of the drive module.

[0028] A system and / or means within the meaning of the present invention can be designed in hardware and / or software, in particular at least one, in particular digital, processing unit, in particular a microprocessor unit (CPU), graphics card (GPU) or the like, preferably connected to a memory and / or bus system for data or signals, and / or one or more programs or program modules. The processing unit can be designed to execute instructions implemented as a program stored in a memory system, to detect input signals from a data bus, and / or to output signals to a data bus. A memory system can have one or more, in particular different, storage media, in particular optical, magnetic, solid-state, and / or other non-volatile media. The program can be designed in such a way that it embodies the methods described here orcapable of carrying out such a method, so that the processing unit can carry out the steps of such methods and thus in particular operate or monitor the machine.

[0029] In one embodiment, a computer program product can comprise, in particular be, a storage medium, in particular a computer-readable and / or non-volatile one, for storing a program or instructions or with a program or instructions stored thereon. In one embodiment, execution of this program or these instructions by a system or a controller, in particular a computer or an arrangement of multiple computers, causes the system or the controller, in particular the computer(s), to carry out a method described here or one or more of its steps, or the program or the instructions are configured to do so.

[0030] In one embodiment, one or more, in particular all, steps of the method are carried out completely or partially automatically, in particular by the controller or its means.

[0031] In one embodiment, the system comprises a multi-axis machine, in particular a robot.

[0032] Embodiments of the invention described herein may be combined (according to the invention) wherever this is technically reasonable and feasible.

[0033] Further advantages and features emerge from the subclaims and the exemplary embodiments. The following shows, partly schematically:

[0034] Fig. 1: a drive module in a plan view with a cycloidal disk with internal electromagnets for its direct drive according to the synchronous reluctance motor principle according to an embodiment of the present invention;

[0035] Fig. 2a and 2b: an extension of the cycloid disk according to

[0036] Embodiments of the present invention;

[0037] Fig. 3 shows a section of a drive module in a sectional view according to embodiments of the present invention; and

[0038] Fig. 4 shows a method for controlling a drive module for a cycloid drive. Figure 1 shows a drive module 1 for a cycloid drive in a plan view with a cycloid disk 10. The cycloid disk 10 comprises bearing holes 5 that are evenly distributed on a circular path concentric with the opening 6 of the cycloid disk 10. Furthermore, Fig. 1 shows an inner support with webs 8, wherein the webs 8 are received in the bearing holes 5 such that the cycloid disk 10 can execute a wobbling movement around the central axis or executes it upon activation of the electromagnets 20 (shown here only with reference to the pole shoes 12). The pole shoes 12 are designed as a pole shoe ring 13. Furthermore, Fig. 1 schematically shows an output 40 via the outer support with output teeth 45.The wobbling motion T of the cycloidal disk 10, which is triggered by (targeted) activation of the electromagnets and thereby forms a moving air gap 21 between the cycloidal disk 10 and the pole shoe ring 13, leads to a rotation of the output 40, shown here as an example. The opening 6 offers the possibility of routing cables, in particular data cables and / or electrical supply lines, through the drive module 1. These then do not have to be routed via an outer side of the machine or robot. The drive module, with its wobbling motion T of the cycloidal disk 10, can alternatively be designed for an output via the internal support provided by the webs. This alternative is not shown in Fig. 1.

[0039] Figure 2a schematically shows a radial section through a portion of the cycloidal disk 10 with an extension 11. The extension 11 of the cycloidal disk 10 points radially inward from the cycloidal disk 10, toward the pole shoe ring 13. The pole shoe ring 13 has a pair of pole shoes with pole shoes 12, which are shown here as an example with a north and a south pole. The extension 11 also sets an air gap 21 when an electromagnet 20 is activated. The air gap 21 shifts according to the wobbling motion T of the cycloidal disk 10. The center of the opening 6 is shown schematically and not to scale with a dashed line (central axis).

[0040] In contrast to Figure 2a, Figure 2b schematically shows a cycloidal disk 10 of a drive module 1 with two extensions 11 that frame the pole shoes 12 of the pole shoe ring 13 in the axial direction. One of the extensions 11 is designed as a separate component and is connected to the cycloidal disk 10. An air gap 21 changes, as described herein, depending on the activation of the electromagnets 20. The pole shoes 12 in Figure 2b preferably have a north pole and a south pole. The electromagnets can also be configured differently, in particular according to an embodiment described herein.

[0041] Figure 3 schematically shows a sectional view through a section of the drive module 1. In the embodiment of Figure 3, the drive module 1 has several cycloid disks 10a, 10b, 10c, which have different thicknesses d1, d2, d3 in the axial direction. The cycloid disks 10a, 10b, 10c are arranged offset from one another such that an overall center of gravity of the cycloid disks 10a, 10b, 10c is (at least essentially) stationary during a wobbling movement of the cycloid disks 10a, 10b, 10c. The center of the opening 6 is shown schematically and not to scale with a dashed line.

[0042] Figure 4 schematically shows a method 100 which, in a first step S10, represents a determination of a position of the cycloid disk, in a second alternative or supplementary step S20, a determination of a position of the output of the drive module 1, and in a third step S30, a control of an electromagnet based on a position after steps S10 and / or S20, if these have been determined.

[0043] Although exemplary embodiments have been explained in the preceding description, it should be noted that a multitude of modifications are possible. Furthermore, it should be noted that the exemplary embodiments are merely examples and are not intended to limit the scope of protection, applications, or structure in any way. Rather, the preceding description provides the skilled person with a guide for implementing at least one exemplary embodiment, whereby various changes, particularly with regard to the function and arrangement of the described components, can be made without departing from the scope of protection as it results from the claims and equivalent combinations of features.

[0044] 1 drive module

[0045] 5 bearing hole

[0046] 6 Opening

[0047] 8 bridge

[0048] 10 Cycloid disc

[0049] 10a, 10b, 10c Cycloid disks

[0050] 11 Expansion

[0051] 12 Pole piece

[0052] 13 Pole shoe ring

[0053] 20 electromagnet

[0054] 21 Air gap

[0055] 25 Cycloid profile

[0056] 30 rotating magnetic field

[0057] 40 external support

[0058] 45 output teeth

[0059] 100 procedures

[0060] T Wobbling movement of the cycloid disk around the webs

[0061] S10 Determining a position of the cycloid disk

[0062] S20 Determining a position of the output

[0063] S30 Controlling an electromagnet

Claims

Patent claims 1. Drive module (1) for a cycloidal drive, comprising: - a cycloidal disk (10), wherein the cycloidal disk (10) is eccentrically wobbleable about a central axis and has a cycloidal profile (25) at its edge which engages at one point with an external support (40); a central opening (6); and has at least three bearing holes (5), - an inner support with at least three webs (8), wherein the bearing holes (5) accommodate the at least three webs (8) and couple the cycloidal disk (10) to the inner support; and - a direct drive which is configured to act magnetically on the cycloidal disk (10) so that the cycloidal disk (10) interacts with a magnetic field of the direct drive and is brought into a wobbling motion translationally via this, wherein an output of the drive module (1) is provided via the outer or the inner support.

2. Drive module (1) according to the preceding claim, characterized in that the direct drive has a pole shoe ring (13) with pole shoes (12) or pairs of pole shoes, wherein the pole shoe ring (13) is arranged in the opening (6) of the cycloidal disk on the central axis and forms an eccentric, rotating air gap to this axis, and wherein the pole shoes (12) are oriented radially outwards in the direction of the cycloidal disk (10).

3. Drive module (1) according to one of the preceding claims, characterized in that the pole shoe ring (13) has the central opening (6), in particular a rigid central opening (6).

4. Drive module (1) according to one of the preceding claims, characterized in that the drive module (1), in particular the cycloidal disk (10), is not actuated by means of an eccentric.

5. Drive module (1) according to one of the preceding claims, characterized in that the drive module (1) does not have permanent magnets. Drive module (1) according to any one of the preceding claims, characterized in that the drive module (1) further comprises at least one sensor. Drive module (1) according to any one of the preceding claims, characterized in that the cycloidal disk (10) has an extension (11) which is formed in an annular manner on the radially inner side of the cycloidal ring (10). Drive module (1) according to any one of the preceding claims, characterized in that the drive module (1) has at least two cycloidal disks (10), wherein the cycloidal disks (10) are arranged such that the overall center of mass of the at least two cycloidal disks (10) lies on the central axis. Drive module (1) according to the preceding claim, characterized in that the at least two cycloidal disks (10) have different thicknesses. Cycloidal drive comprising a drive module (1) according to any one of the preceding claims.Method for controlling a drive module (1) for a cycloidal drive, in particular a cycloidal drive, according to one of the preceding claims, wherein the method comprises:. - Determining (S10) a position of the cycloidal disk (10); and / or - Determining (S20) the position of an output of the drive module (1); - Controlling (S30) the at least one electromagnet (20) of at least one pole shoe (12) such that the cycloidal disk (10) of the drive module (10) is positioned and / or moved, based on the determined position of the cycloidal disk (10) and / or the determined position of the output. System for operating and / or monitoring a drive module (1), in particular a drive module (1) for a multi-axis machine, which is used for A computer program or computer program product, wherein the computer program or computer program product, in particular stored on a computer-readable and / or non-volatile storage medium, contains instructions which, when executed by one or more computers or a system according to claim 12, cause the computer(s) or system to perform a method according to claim 11.

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