Articulated arm

Abstract

The invention relates to an articulated arm having two hollow arm parts (1) which are connected to each other in an articulated manner by means of a pivot drive (2) which has a ring gear (4) arranged in one hollow arm part (1) and a motor (7) arranged in the other hollow arm part (1), the pinion (9) of which meshes with the ring gear (4).

Description

Technical Field

[0001] The present invention relates to an articulated arm, in particular as a structural element of a robot for painting motor vehicles, for example, used in a painting line. Background Art

[0002] A painting line for painting motor vehicles is known from EP1263535 A1. The articulated arm of the robot carries, for example, a spraying tool at its free end for spraying the vehicle. The articulated arm has at least two arm members, which are hingedly connected to each other by means of pivot hinges. The arm members can move relative to each other in different angular positions. For this purpose, a motor is provided, and when the motor is actuated, the arm members pivot relative to each other. In such a painting line, it is expedient for the articulated arm to be movably and elongately designed. Summary of the Invention

[0003] The object of the present invention is to provide an articulated arm that enables a simple and elongate structure.

[0004] According to the present invention, the object has been achieved by the articulated arm according to claim 1. Expedient improvements are given in dependent claims 2 to 8.

[0005] The articulated arm is provided with at least two arm members, which are hingedly connected to each other by means of a pivot drive. The arm members are preferably implemented as elongate hollow members, which accommodate members such as control elements, cables, and also motors.

[0006] The pivot drive can have a unique pivot plane, which is inclined with respect to the longitudinal axes of the pivotably movable arm members. In this case, the motor is arranged in one hollow arm member, and the toothed ring is arranged in the other hollow arm member. The pinion of the motor meshes with the toothed ring. When the motor is actuated, the two arm members twist relative to each other about a pivot axis perpendicular to the pivot plane. The pivot plane and the plane of the toothed ring are arranged parallel to each other.

[0007] Preferably, an intermediate hollow arm member of the articulated arm is provided, and adjacent hollow arm members are respectively supported at both ends of the intermediate hollow arm member. In this case, the pivot drive has two pivot planes: one pivot plane is located between one adjacent arm member and the intermediate arm member. The other pivot plane is located between the other adjacent arm member and the intermediate arm member. These two pivot planes are inclined with respect to the longitudinal axis of the arm member.

[0008] In this case, two motors are advantageous:

[0009] Two motors can be accommodated in the middle hollow arm member, and two ring gears are respectively accommodated in one of the adjacent arm members.

[0010] The two motors can be respectively accommodated in one of the adjacent hollow arm members, and the two ring gears are accommodated in the middle arm member.

[0011] One motor and one ring gear can be accommodated in the middle arm member, while the other motor can be accommodated in one of the adjacent hollow arm members, and the other ring gear can be accommodated in the other adjacent hollow arm member.

[0012] In any case, the pinion of the motor meshes with the ring gear. The motor can be configured as a variable-speed motor. In any case, the pinion of the motor or the variable-speed motor meshes with the respective ring gear.

[0013] In the above-described manner, very good movability of the arm members relative to each other can be configured, and the adjustment speed of the two arm members relative to each other can be increased. For example, when the rotational directions of the moving arm members are opposite, the speeds of the oppositely moving arm members can be at least partially added.

[0014] In a very simple structural form, the arm members can be configured tubularly such that an elongated and cost-effective articulated arm can be provided, which can accommodate not only the motors but also the ring gears and electrical circuits. In this arrangement, reliable protection of the accommodated components from the unwanted intrusion of foreign objects, such as paint mist, can be ensured.

[0015] The pivot drive can be sealed by means of common seals to prevent the intrusion of paint mist or other foreign objects into the hollow arm member.

[0016] For very good spatial movability, it can be proposed that the two ring gear axes of the ring gears are inclined relative to each other in the middle arm member at an inclination angle greater than 90 degrees and less than 180 degrees. At this inclination angle, the two adjacent arm members are respectively pivotally movably supported relative to each other at the middle arm member.

[0017] The two pivot planes on both sides of the middle arm member are parallel to the plane in which the respective ring gear is located. The pivoting of one or two adjacent arm members relative to the middle arm member changes the angular position of the two adjacent arm members relative to each other.

[0018] Preferably, the arm members arranged adjacent to each other are rotatably movably supported on each other by means of pivot bearings, and the pivot axis of the pivot bearings coincides with the axis of the ring gear. These axes are perpendicular to the pivot plane. The pivot bearings can be implemented as sliding bearings or can also be implemented as rolling bearings. The pivot bearings transmit the forces and torques acting between the mutually supported arm members.

[0019] Preferably, the ring gear is embodied as a hollow wheel having an internal tooth section, and the pinion of the motor or the variable speed motor meshes with the hollow wheel.

[0020] Preferably, the tubular arm member has a hollow cylindrical bearing seat at its inner circumference for receiving the cylindrical hollow wheel. The bearing seat can be stepped, such that a shoulder is formed having axial and radial support surfaces for supporting the hollow wheel. The hollow wheel can be inserted with its cylindrical side surface into the hollow cylindrical bearing seat, wherein the end face of the hollow wheel abuts against the axial support surface of the stepped bearing seat.

[0021] The articulated arm according to the invention is particularly suitable for a robot, which can perform work in space by means of such an articulated arm. A favorable application according to the invention is a robot for a painting line, which is equipped with such an articulated arm. By fitting the complete pivot drive into the hollow arm member, a highly movable and slender articulated arm is provided, the drive and the electrical connections of which are protected against the paint mist generated during the operation of the robot. Description of the Drawings

[0022] The invention will be explained in detail below on the basis of the embodiments depicted in two drawings. The drawings show:

[0023] Figure 1 A painting robot with an articulated arm is schematically shown, and

[0024] Figure 2 A partial schematic view of the articulated arm according to the invention is shown. Detailed Description of the Invention

[0025] Figure 1 A painting robot with an articulated arm is shown in section. Each articulated arm has two arm members 1, which are articulated to each other by means of a pivot drive 2. For example, the free end of the articulated arm carries a spraying tool for spraying the body of a vehicle. Here, only the pivot drive 2 is outlined and will be explained in detail with the aid of Figure 2 a partial enlarged view in.

[0026] The intermediate hollow arm member 3 is chamfered at its ends facing away from each other. The chamfered ends form pivot planes, which are inclined relative to each other. The intermediate arm member 3 carries ring gears 4 at both ends, which are embodied as hollow wheels 5 having an internal tooth section 6. The ring gears 4 are located in two hollow wheel planes inclined relative to each other, which are parallel to the chamfered ends.

[0027] Two hollow arm members 1 each carry a motor 7 at their ends facing the intermediate arm member 3 and cut at an inclined plane, and the motors are fastened on the inner circumferences of the corresponding hollow arm members 1. The motor shafts 8 carry pinions 9, and the pinions mesh with the adjacent hollow wheels 5.

[0028] Pivot bearings 10 are respectively fitted between the inclined ends of the intermediate arm member 3 and the two adjacent arm members 1, and the pivot bearings enable relative rotation between the intermediate arm member 3 and the two connected adjacent arm members 1 about a pivot axis perpendicular to the plane of the pivot bearings 10. The plane of the pivot bearings 10 is parallel to the plane of the hollow wheels 5 of the hollow wheels.

[0029] The motors 7 and the hollow wheels 5 including the required electrical wiring not depicted are arranged in a protected manner within the hollow pivot hinge 2 and the hollow arm members.

[0030] The hollow wheel axes of the hollow wheels 5 are arranged to be inclined with respect to each other at an inclination angle greater than 90 degrees and less than 180 degrees. The hollow wheel axes are perpendicular to the plane of the toothed ring and perpendicular to the plane of the corresponding pivot bearings 10. The hollow wheel axes and the pivot bearing axes coincide.

[0031] List of reference numerals

[0032] 1 Arm member

[0033] 2 Pivot drive

[0034] 3 Intermediate arm member

[0035] 4 Toothed ring

[0036] 5 Hollow wheel

[0037] 6 Inner toothed portion

[0038] 7 Motor

[0039] 8 Motor shaft

[0040] 9 Pinion

[0041] 10 Pivot bearing.

Claims

1. An articulated arm having two hollow arm members (1), the two hollow arm members being hingedly connected to each other by means of a pivot drive (2), the pivot drive having a toothed ring (4) provided in one hollow arm member (1) and a motor (7) provided in the other hollow arm member (1), the pinion (9) of the motor meshing with the toothed ring (4).

2. The articulated arm according to claim 1, wherein the pivot drive (2) of the articulated arm has an intermediate hollow arm member (3), and adjacent arm members (1) are pivotally supported at both ends of the intermediate hollow arm member respectively.

3. The articulated arm according to claim 2, wherein the intermediate hollow arm member (3) of the articulated arm carries a toothed ring (4) at both of its opposite ends, and each pinion (9) of two motors (7) received in two adjacent hollow arm members (1) meshes with the toothed ring.

4. The articulated arm according to claim 1 or 2, wherein the intermediate hollow arm member (3) of the articulated arm houses two motors (7), and toothed rings (4) are respectively fastened in the adjacent arm members (1) of the articulated arm, and the pinions (9) of the motors (7) respectively mesh with one of the toothed rings (4).

5. The articulated arm according to claim 3 or 4, wherein the two toothed ring axes of the toothed rings (4) of the articulated arm are arranged inclined with respect to each other at an inclination angle greater than 90 degrees and less than 180 degrees.

6. The articulated arm according to any one of claims 3 or 4, wherein the toothed ring (4) of the articulated arm is implemented as a hollow wheel (5) having an internal tooth portion (6).

7. The articulated arm according to any one of claims 1 to 4, wherein the arm members (1, 3) of the articulated arm are rotatably supported on each other by means of pivot bearings (10), and the pivot axis of the pivot bearing coincides with the axis of the toothed ring.

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