DRIVE DEVICE FOR A MANIPULATOR

Description

[0001] The present invention relates to a drive device for a joint between two axle members of a manipulator of a robot system.

[0002] Drive units used in manipulators of robot systems or robot arms serve to position one axis element of the typically multi-axis robot arm so that it is movable, preferably rotatable, relative to an adjacent axis element. The resulting mobility between two adjacent axis elements, determined by the number of axis elements in the manipulator, gives the robot system its corresponding degrees of freedom.

[0003] Industrial robots utilize drive units that allow an axle member to rotate around an axis perpendicular to its longitudinal axis. Other drive devices are designed to allow rotation around the longitudinal axis of the axle member. These typically employ appropriately sized electric motors, which may interact with a suitable reduction gearbox.

[0004] In lightweight robots, the drive devices are installed in the self-contained housing of the axis elements, since the housings of the manipulators of such robot types are basically designed like an exoskeleton.

[0005] In drive devices known from the prior art, at least one sensor device is generally provided on the output side to detect the position, torque, and / or speed of a driven element that rotates one axle member relative to the other axle member. Furthermore, an additional sensor device is provided on the motor side or drive side to detect the drive speed, drive torque, and / or position of a drive shaft driven by a motor.

[0006] In order to enable a particularly compact design, a drive device, especially for use in lightweight robots, has been proposed in German Patent No. 10 2016 004 810, in which both sensor devices are arranged on a single circuit board.

[0007] This drive device for a joint arranged between two axis members of a manipulator of a robot system for the rotary drive of one axis member relative to the other axis member comprises a motor that drives a drive shaft and an output element that is connected to one axis member and is set in rotation directly or indirectly by the drive shaft, wherein a printed circuit board (PCB) is provided on which a sensor device for the drive provided by the drive shaft and a sensor device for the output provided by the output element are arranged, wherein the sensor device for the drive and the sensor device for the output are arranged on opposite sides of the printed circuit board.

[0008] Furthermore, a sensor shaft is provided to which the output element is rotationally fixed. The sensor shaft extends through an opening in the circuit board to the side of the circuit board opposite the motor. A position or sensor ring is provided above the circuit board in the region of the axial end of the sensor shaft, which interacts with the sensor device for the output. The sensor ring is rotatably mounted in a bearing seat and rotationally fixed to the sensor shaft.

[0009] In such a design of the drive device from the prior art, as exemplified in the Fig. 1 As shown, all electronic components for controlling the drive system (both the output and the input), sensor devices, and other control and power components are therefore densely packed on a single circuit board. Consequently, the heat generated by the individual electronic components on the circuit board is considerable, particularly during relatively long, continuous operation of the robot.

[0010] In principle, excessive heat generation in the area of ​​the circuit board must be avoided to prevent unnecessary compromise of the functional reliability of the electronic components and thus the robot's control system through malfunctions and failures. Furthermore, the problem arises that with exoskeleton-like housing structures of manipulators, heat is dissipated very poorly, or at least not quickly enough, from the circuit board area. Fluid-based cooling systems are generally unsuitable for this purpose due to the manipulators' mobility.

[0011] Heat sinks in the area of ​​drive units, especially for robot arms, are known, for example, from WO 2015 / 131904 A1 and DE 10 2015 225 750 A1.

[0012] Based on this, an object of the present invention is to provide a drive device for a manipulator of a robot system, particularly, but not exclusively, of lightweight design, located between two axis members, which eliminates the aforementioned disadvantages known from the prior art, and in particular provides a means of effectively dissipating the heat generated in the area of ​​electronic components. Specifically, the invention aims to further develop the drive device known from the aforementioned DE 10 2016 004 810 accordingly.

[0013] This problem is solved with a drive device according to claim 1 and with a robot according to claim 5.

[0014] The invention therefore relates to a drive device for a joint arranged between two axis members of a manipulator of a robot system for the rotary drive of one axis member relative to the other axis member, comprising a motor that drives a drive shaft, an output element that is connected to one axis member and is set in rotation directly or indirectly by the drive shaft, a circuit board on which a sensor device for the drive provided by the drive shaft, a sensor device for the output provided by the output element and control electronics for controlling the drive device are arranged, wherein at least one heat sink is provided that thermally connects the circuit board to a housing or housing section of the motor.

[0015] According to the invention, the heat sink is arranged in relation to the circuit board such that it attacks a point on the circuit board that is opposite the electronic components of the control electronics arranged on the circuit board, from which the heat to be dissipated is generated.

[0016] To avoid damaging the circuit board, it is recommended that at least one thermally conductive gap filler, for example made of silicone or another suitable plastic, be provided between the circuit board and the heat sink.

[0017] Furthermore, in order to avoid damaging the circuit board or its surface or the electronic components located on it during the assembly of the drive device, the thermally conductive gap filler is provided in a recess of the heat sink in such a way that it cannot slip during the assembly and disassembly of the drive device as well as during the operation of the manipulator.

[0018] According to the invention, the heat sink is formed integrally with the housing or housing section of the motor, for example by being milled from a common metal body.

[0019] The heat sink can be fixed and precisely positioned relative to the circuit board by screwing the circuit board to the motor housing.

[0020] To ensure effective heat dissipation from the circuit board, the heat sink has a shape and design that, in the area of ​​contact with the circuit board, is aligned with the geometric distribution of the electronic components of the control electronics. In other words, the contour or cross-section of the heat sink in the radial direction of the drive device follows the arrangement of the heat-generating control electronics.

[0021] In order to enable even further heat dissipation, it may also be provided that the heat sink is in a thermally conductive connection with the housing of an arm link of the manipulator, which is usually also made of metal, e.g. via appropriately designed thermally conductive struts in the radial direction.

[0022] Providing a heat sink, whose shape, dimensions, and material can be adapted in advance to the thermal properties of the printed circuit board and the geometric arrangement of the electronic components, ensures that the heat generated in the area of ​​the circuit board can be dissipated. This prevents heat build-up that could impair or even damage the operational reliability of the control electronics and sensor devices. Integrating the heat sink preferably as a component of the motor housing allows for simple and cost-effective manufacturing and also enables easy assembly.

[0023] In this context, the invention therefore also relates to a robot with a manipulator comprising several axis members and a drive device according to the embodiments described above in at least one joint arranged between axis members of the manipulator.

[0024] Further advantages and features will become apparent from the description of the exemplary embodiment illustrated with the accompanying drawings. These show: Fig. 1 shows an axial longitudinal section through a drive device according to the prior art; Fig. 2 shows a perspective view of a housing section of the motor; Fig. 3 shows a perspective view of a housing section of the motor with a gap filler; and Fig. 4 shows a schematic of the assembly of a housing section with a circuit board of the drive device.

[0025] In the Fig. 1 For the purpose of understanding, an exemplary drive device from the prior art is shown in a cross-sectional view along the axis of rotation, i.e., longitudinal extent of the drive device, as is known, for example, from German Patent No. 10 2016 004 810.

[0026] As can be seen, the drive device is essentially composed of rotationally symmetrical components and parts, employing a modular design in which several modules functionally interact and interlock in an axial orientation. The modules are individually replaceable and can be connected to each other using appropriately designed and implemented connection techniques.

[0027] The in Fig. 1 The drive device shown essentially consists of four functionally different drive modules.

[0028] A first drive module M1 includes a gearbox 1, for example a wave gear, which is housed in a casing 2. The output element of the gearbox 1 is connected via an output shaft 3 to a casing 4 of a second drive module M2 in a rotationally fixed, i.e., torque-transmitting, manner. The second drive module M2 serves as the output and is, for this purpose, rotationally fixed to an axle element (not shown) of a manipulator or robot arm, while the casing 2 of the first drive module M1 is connected to another axle element (not shown) of this manipulator. The casing 4 of the second drive module M2 is rotatably mounted relative to the casing 2 of the first drive module M1 by means of a radial bearing 5.

[0029] A third drive module M3 is attached axially opposite the second drive module M2 to the first drive module M1, which has a housing 6 in which a motor 7 is arranged that drives a motor or drive shaft 8.

[0030] The drive shaft 8 is rotatable by means of a first radial bearing 9 near the gearbox 1 and by means of a second radial bearing 10 in a cover 11 for the housing 6 and is thus centrally mounted in the drive device.

[0031] A fourth drive module M4, which has a circuit board 13 or PCB for sensor and control electronics, is attached to the housing 6 of the third drive module M3 or to the cover 11 associated with it via connecting or spacer 12.

[0032] The drive shaft 8 of the motor 7, which is designed as a hollow shaft, extends through the cover 11 to the side of the circuit board 13 that faces the cover 11.

[0033] The housing 4 of the second drive module M2 is screwed to a flange 15 of a sensor shaft 16 at its end face via a flange 14 in a rotationally fixed manner.

[0034] As in the Fig. 1 As can be seen, the sensor shaft 16 passes through the output shaft 3 and the drive shaft 8 of the motor 7 at a radial distance and extends through an opening in the circuit board 13 to the side of the circuit board 13 that is opposite the third drive module M3.

[0035] The axial end of the drive shaft 8, facing the circuit board 13, has a sensor ring 17, while a sensor chip 18 corresponding to this sensor ring 17 is arranged on the circuit board 13. The sensor ring 17 is mounted on a retaining ring 19, so that the sensor ring 17 rotates with the drive shaft 8.

[0036] The sensor shaft 16 also has a sensor ring 20 at its axial end, which is also attached in a corresponding retaining ring 21 and thus rotates on the circuit board 13 via a sensor chip 22 assigned to this sensor ring 20.

[0037] In order to guide the sensor ring 20 of the sensor shaft 16 exactly concentrically and parallel to the sensor chip 22, a radial sliding guide 23 is arranged on the circuit board 13 in this state of the art, which is screwed to the spacers 12.

[0038] In order to guide the sensor ring 17 of the drive shaft 8 exactly concentrically and parallel to the sensor chip 18, the second radial bearing 10 of the third drive module M3 is arranged as close as possible to the circuit board 13.

[0039] The present invention relates in the broadest sense to the design of modules M3 and M4 and their connection, and is therefore, in principle, independent of the actual design of the further modules M1 to M4 and their components. However, the structure of these modules can, in principle, be implemented analogously to the prior art.

[0040] In the Fig. 2 An upper housing section or housing cover 11 of the motor 7 is shown.

[0041] In addition to the spacers 12, which also have an internal thread for receiving screws with which the circuit board 13 is connected to the housing cover 11, this has a heat sink 24 at a corresponding location, which is formed integrally with the housing cover 11.

[0042] A recess 25 is provided on the surface of the heat sink 24, which serves to receive a thermally conductive pad or gap filler 26, as shown in the Fig. 3 shows.

[0043] With the gap filler 26, the heat sink 24, in its assembled state, contacts the underside of the circuit board 13, where corresponding electronic components may be located on both sides of the circuit board 13, and whose heat is to be dissipated, as shown in the Fig. 4 shown.

[0044] Due to the material properties and the larger mass of the housing cover 11 with the integral heat sink 24, the heat generated in the area of ​​the circuit board 13 can be effectively dissipated from it according to the invention, so that excessive heat development that impairs functional reliability can be effectively avoided there.

Claims

1. Drive device for a joint arranged between two axle members of a manipulator of a robot system for rotary drive of one axle member relative to the other axle member, - with a motor (7) which drives a drive shaft (8), with an output element (3, 4) which is connected to the one axle member and is set into rotation directly or indirectly by the drive shaft (8), - with a printed circuit board (13) on which a sensor device (18) for the drive provided by the drive shaft (8), a sensor device (22) for the drive provided by the output element (3, 4), and a control electronics for controlling the drive device are arranged, - wherein the motor (7) has a housing with a cover (11) on which a spacer (12) is provided for fastening the printed circuit board (13) extending in the radial direction of the drive shaft, - wherein at least one heat sink (24) is arranged integrally with the cover (11) of the housing (6) which extends in the axial direction to below the printed circuit board (13) while maintaining a distance - wherein at least one thermally conductive gap filler (26) is arranged between the printed circuit board (13) and the heat sink (24), and - wherein the heat sink (24) in the assembled state is in thermally conductive contact with the side of the printed circuit board facing the cover via the gap filler (26).

2. Drive device according to claim 1, wherein the thermally conductive gap filler (26) is arranged wihin a recess (25) of the heat sink (24).

3. Drive device according to one of the preceding claims, wherein the heat sink (24) has a shape and design which, in the area of contact with the printed circuit board (13), is aligned with the geometric distribution of the electronic components of the control electronics.

4. Drive device according to one of the preceding claims, wherein the heat sink (24) is in a thermally conductive connection with the housing of an arm member of the manipulator.

5. Robot with a manipulator comprising several axle members, having a drive device according to claims 1 to 4 in at least one joint arranged between axle members of the manipulator.