JOINT UNIT, JOINT SYSTEM, ROBOT FOR MANIPULATION AND/OR TRANSPORTATION, ROBOTIC EXOSKELETON SYSTEM AND METHOD FOR MANIPULATION AND/OR TRANSPORTATION

Abstract

A joint unit, in particular a joint unit of a robot, a joint system, a robot for manipulation and/or transportation, in particular for transportation of an object, a robotic exoskeleton system and a method for manipulation and/or transportation, in particular for transportation of an object, in particular for moving a body. The joint unit has a rotary drive, a gear, at least one spring element and a joint output. The gear has a gear input and a gear output, wherein the gear input is mechanically coupled to the rotary drive and suitable for transformation of the torque provided by the rotary drive. The spring element is mechanically coupled to the gear output and suitable for at least partial storing of the torque provided by the gear output and/or of the torque provided by an external load applied to the joint unit.

Claims

1. Joint unit, in particular joint unit of a robot, comprising in series connection: a rotary drive, a gear for transformation of the torque provided by the rotary drive, wherein the gear comprises a gear input and a gear output, wherein the gear input is mechanically coupled to the rotary drive, at least one spring element for at least partial storing of the torque provided by the gear output and/or of the torque provided by an external load applied to the joint unit, wherein the spring element is mechanically coupled to the gear output, and a joint output which is mechanically coupled to the spring element for transmitting the torque realized by the rotary drive and/or stored by the spring element.

2. Joint unit according to claim 1, wherein the gear is a strain wave gear.

3. Joint unit according to claim 1, wherein the joint output is realized as an axle, preferably a hollow axle.

4. Joint unit according to claim 1, wherein the rotary drive comprises a stator and the joint unit comprises a connecting member provided on the stator.

5. Joint unit according to claim 1, wherein the spring element is a spiral spring.

6. Joint unit according to claim 5, wherein the spiral spring comprises at least two wound strips, particularly concentrically, each comprising three sections along the longitudinal direction of the respective strip, wherein a middle section provided between a center section arranged in the center part and a distal section arranged at a distal end has a cross section which is bigger than the cross sections of the center section and the distal section.

7. Joint unit according to claim 1, comprising a joint output angle sensing device.

8. Joint unit according to claim 1, wherein the rotary drive comprises a rotor and a position sensing device adapted to sense the angular position of the rotor.

9. Joint unit according to claim 1, comprising a gear output angle sensing device.

10. Joint unit according to claim 1, comprising a slip ring for the transmission of electrical signals and/or power between members of the joint unit that are movable with respect to each other.

11. Joint system, comprising at least two joint units as claimed in claim 1, wherein the joint units are mechanically connected in series.

12. Robot for manipulation and/or transportation, in particular for transportation of an object, comprising at least one joint unit as claimed in claim 1.

13. Robot for manipulation and/or transportation according to claim 12, wherein the robot is a driving robot and comprises at least one wheel, and at least one joint unit or at least one joint system is connected or connectable to the wheel in order to drive the wheel.

14. Robotic exoskeleton system, comprising a joint unit as claimed in claim 1 and two fixing devices for the fixation on body parts of mammals, particularly humans, wherein the first fixing device is mechanically connected or connectable to the stator of the rotary drive and the second fixing device is mechanically connected or connectable to the rotor of the rotary drive.

15. Method for manipulation and/or transportation, in particular for transportation of an object, in particular for moving a body, wherein a joint unit as claimed in claim 1 is provided, energy is supplied to the rotary drive, torque provided by the rotary drive is transformed by the gear, the spring element is loaded by the torque provided by the gear, torque provided by the spring element is transmitted to the joint output, torque provided by the joint output is applied to the object such that the object is manipulated and/or transported.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0095] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0096] FIG. 1 shows a cross section of a joint unit according to the invention,

[0097] FIG. 2 shows a schematic section of a part of a joint unit according to the invention,

[0098] FIG. 3 shows a top view and a perspective view of a spiral spring according to the invention,

[0099] FIG. 4 shows a top view, a cross section and two perspective views of the back of the housing of the joint unit according to the invention,

[0100] FIG. 5 shows two perspective views of a joint unit according to the invention,

[0101] FIG. 6 shows a side view of a joint unit according to the invention with the housing displayed transparently.

DETAILED DESCRIPTION

[0102] FIG. 1 shows a cross section of a joint unit 40 according to the invention. The joint output 8 is realized as a lightweight hollow axle on which the rotary drive 2, realized as brushless electric motor with high power density and low inertia, the gear 5, realized as strain wave gear, e.g. harmonic drive gear, and the spring element 7, realized as spiral spring, are arranged. The stator 50 of the rotary drive 2, namely of the motor, is mounted directly to the back of the housing 1 which employs cooling fins for increased convective heat dissipation (not shown here). Its rotor 51 is connected to the motor-gear transmission shaft 4 which drives the gear 5. The motor-gear transmission shaft 4 is a pivoted axle being supported on the joint output 8 by a bearing 21 and supported on the housing 1 by another bearing 22. The housing 1 surrounds and encapsulates all functional units.

[0103] The control unit 3, comprising a motor output position sensing device, is arranged close to the rotary drive 2 and positioned and functionally included in its stator 50. The gear 5 transforms the torque with a ratio >1, so the speed is significantly reduced while the torque is significantly increased. The gear-spring transmission shaft 6, a hollow shaft, is supported with a bearing 24 from the joint output 8 and transmits the transformed rotational movement to the spring element 7, which drives the joint output 8. The joint output 8 is supported on the housing 1 with bearings 20 and 25 and sealed with sealing rings 30 and 34. The housing 1 is subdivided onto a rear part, shown on the left hand side, a central part which is essentially cylindrical and a front part, shown on the right hand side, referred to as connection element 9. The central part of the housing 1 is sealed with sealing rings 31 and 33 from the rear and front parts.

[0104] The gear output angle sensing device 100 (shown by its components as follows) comprises a reading head 10, attached to the housing 1, and a magnetic ring 11, attached to the rotating gear-spring transmission shaft 6. Similarly, the joint output angle sensing device 110 comprises a reading head 12, attached to the housing 1, and a magnetic ring 13, attached to the joint output 8.

[0105] FIG. 2 shows a schematic section of bisected joint unit 40 according to the invention in a simplified representation. The rotary drive 2 comprises a stator 50 and a rotor 51. It is controlled by the control unit 3 and drives the gear 5 which transforms the movement. The gear output is connected to the spring element 7 which protects the gear 5 by decoupling it from peak loads exerted via the joint output 8, realized as hollow axle. All described elements are arranged around the hollow axle.

[0106] A gear output angle sensing device 100 and a joint output angle sensing device 110 sense the positions of said elements and act as data input for the control unit 3.

[0107] FIG. 3 shows a top view and a perspective view of a spring element 7, namely a spiral spring, according to the invention. It comprises a first strip 70 and a second strip 71, which are concentrically wound in form of spirals, respectively, around a central axis. The strips are interconnected forming an inner connection area 72 for a pivoted element to be connected, realized as holes. The inner connection area 72 of the spring particularly leaves sufficient space around the central winding axis for the hollow axle. Besides, each strip 70, 71 comprises an outer connection area 73, realized as holes.

[0108] Each strip 70, 71 has a cross section with an expansion and a subsequent reduction with the length of the strip 70, 71. In other words, the strips 70, 71 each have a maximum cross section between two sections with a smaller cross section in front of and behind the described maximum. The cross sections near the inner connection area 72 and near the outer connection area 73 is smaller than the cross section in between said areas. While the width remains constant, the thickness of the strips 71, 72 varies with length.

[0109] In this specific embodiment, the thickness of the spring varies from approximately 3.3 mm near the inner connection area 72 to approximately 6.5 mm at the peak to approximately 2.7 mm near the outer connection area 73. The width is constant at 10 mm. The spring constant is approximately 160 Nm/rad. The two strips 70, 71 are wound by approximately 450.

[0110] FIG. 4 shows a top view, a cross section and two perspective views of a part of the joint unit 40 according to the invention: The part shown is the back of the housing 1, comprising the stator 50 of the rotary drive 2, namely of the motor, and the control unit 3. As already mentioned, the back of the housing 1 employs cooling fins for increased convective heat dissipation, visible in the right hand side figures. The control unit 3 is smoothly integrated into the stator.

[0111] FIG. 5 shows two perspective views of a joint unit 40 according to the invention. The compact and integrated design of the joint unit 40 becomes visible in this representation. All functional units are encapsulated in the housing 1. The joint output 8 is realized as hollow axle. On the front of the housing 1, the connection element 9 is arranged. It comprises holes 60 for a connection to a linking member or a separate functional unit. The back of the housing 1, comprising the stator 50 of the rotary drive 2, is equipped with cooling fins, as described.

[0112] FIG. 6 shows a side view of a joint unit 40 according to the invention. The housing 1 is displayed transparently for a better visibility of the functional units. The rotary drive 2 is mechanically coupled to the gear 5, which comprises a gear output angle sensing device 100, of which the reading head 10 is shown. The gear 5 is further mechanically coupled to the spring element 7, which is connected to the joint output 8. The joint output 8 comprises a joint output angle sensing device 110, of which, similarly, the reading head 12 is shown.

[0113] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.