JPH0751268Y2 - Wrist mechanism of industrial robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a wrist mechanism of an industrial robot having a coaxial wrist mechanism that can be easily converted into an offset wrist mechanism.

[Prior Art] Conventionally, as a wrist mechanism provided at the tip of an arm of an industrial robot, there is a coaxial wrist mechanism in which the center line of the arm and the center line of the output shaft of the wrist mechanism coincide with each other. A wrist mechanism has been proposed in which a bending shaft speed reducer is provided on the side surface and a torsion shaft speed reducer is provided on the front surface so as to have at least two degrees of freedom (for example, JP-A-62-213987).
No. 63-185595).

However, the coaxial wrist mechanism is inconvenient depending on the type of the end effector provided on the wrist of the robot, and thus an offset wrist mechanism in which the center line of the arm and the center line of the output shaft of the wrist mechanism are deviated from each other may be required.

[Problems to be Solved by the Invention] In the configuration of the proposed coaxial wrist mechanism, it is difficult to simply replace only the wrist mechanism with the offset wrist mechanism. Therefore, in order to meet such a demand, it is necessary to separately prepare and place the assembly parts for the coaxial wrist mechanism and the offset wrist mechanism, which increases the number of parts and complicates the work management of the manufacturing process. There was a problem such as high cost.

It is an object of the present invention to reduce the number of parts required for exchanging a coaxial wrist mechanism and an offset wrist mechanism so as to facilitate the exchange of both mechanisms.

[Means for Solving the Problem] The present invention is provided with a wrist portion 5 at the tip of the arm 1 which is rotatable about a rotation axis perpendicular to the longitudinal direction of the hollow arm 1, The bending shaft reducer 4 is provided on a side surface mounting portion of the portion 5 which is perpendicular to the rotation axis, and the wrist portion 5 is provided.
In a wrist mechanism of an industrial robot in which a torsion shaft speed reducer 8 is provided in a front mounting portion parallel to the rotation axis of the robot, the wrist mechanism of the industrial robot is supported inside the arm 1. The wrist 5 is provided with an inlay portion 53 provided on the front attachment portion offset from the center of the bending drive shaft 2 for rotating the wrist portion 5, and a stepped portion 72 fitted to the inlay portion 53. A gear shaft driven by the torsion drive shaft 6 concentrically with the stepped portion 72
The reduction gear housing 7 supporting the 68 and having the spigot 74 concentric with the bending drive shaft 2 and fixing the reduction gear 8 for the torsion shaft, the gear shaft 68 and the reduction gear 8 for the torsion shaft. And a transmission device to be connected.

[Operation] A spigot portion is provided at a position offset from the center of a bending drive shaft that rotates a wrist portion provided at the tip of a robot arm, and twists concentrically with a stepped portion that fits into the spigot portion of the wrist portion. Since the gear shaft driven by the drive shaft is supported, and the spigot housing concentric with the bending drive shaft is provided and the reducer housing to which the reducer for the torsion shaft is fixed is provided, the input shaft of the reducer for the torsion shaft is provided. The coaxial wrist mechanism can be easily switched to the offset wrist mechanism simply by replacing the transmission device such as the fixed pulley and the reduction gear housing and replacing the torsion shaft reduction gear.

[Embodiment] An embodiment of the present invention shown in the drawings will be described.

FIG. 1 is a side sectional view showing an embodiment of a coaxial wrist mechanism of the present invention, in which a gear housing 3 is fixed to the tip of a hollow arm 1 and a hollow bending drive shaft 2 is bearing inside the arm 1.
A bevel gear 22 is fixed to the tip of the bending drive shaft 2 by being supported via 21. Input shaft of bevel gear 23 that meshes with bevel gear 22
The fixed portion 42 of the bending shaft reduction gear 4 fixed to 41 is fixed to the gear housing 3. A side mounting portion 51 of the wrist portion 5 is fixed to the output shaft 43 of the bending shaft reduction gear 4 so that it can rotate with respect to the gear housing 3. A torsion drive shaft 6 is provided inside the hollow bending drive shaft 2 and the gear housing 3.
Are supported via bearings 61 and 62, and a bevel gear 63 is fixed. Bearing housing 31 fixed to the gear housing 3
A bevel gear 64 meshing with the bevel gear 63 is fixed at one end, and a gear shaft 66 having a bevel gear 65 fixed at the other end is supported via a bearing 32. A spigot portion 53, which is orthogonal to the gear shaft 66 and is offset from the center of the bending drive shaft 2, is provided on the front attachment portion 52 of the wrist portion 5. The reducer housing 7 provided with the bearing housing 71 and the stepped portion 72 concentric with the inlay portion 53 is fitted into the inlay portion 53, and is fixed to the wrist portion 5. The bearing housing 71 supports a gear shaft 68 having a bevel gear 67 meshing with the bevel gear 65 fixed at one end and concentric with the spigot portion 53 via a bearing 69. Further, on the side opposite to the stepped portion 72 of the speed reducer housing 7, an inlay portion 73 is provided concentrically with the inlay portion 53, and an inlay portion 74 is provided at a position concentric with the bending drive shaft 2 for reducing the speed of the torsion shaft. The fixed portion 81 of the machine 8 is fixed to the spigot portion 74. The input shaft 82 of the torsion shaft reducer 8 includes a gear shaft 68, a pulley 83 fixed to the other end of the gear shaft 68, a timing belt 84, and an input shaft.
They are connected to each other via a pulley 85 fixed to 82. A torsion shaft 87 is fixed to the output shaft 86 of the torsion shaft speed reducer 8. Reference numeral 75 is a cover of the reduction gear housing 7, and 9 is a tension pulley for adjusting the tension of the timing belt 84.

When the coaxial wrist mechanism of FIG. 1 is changed to the offset wrist mechanism, as shown in FIG. 2, the cover 75 is removed and the fixing portion 81 of the torsion shaft reducer 8 is fitted and fixed to the spigot portion 73. Then, the input shaft 82 is connected to the gear shaft 68, or the bevel gear 67 is fixed directly to the input shaft 82.

Further, as shown in FIG. 3, the speed reducer housing 7 is replaced with a speed reducer housing 7 ′ having a simple structure dedicated to an offset wrist mechanism, and the fitting portion of the fixed portion 81 has a different diameter at the fitting portion. May be applicable to.

Further, as shown in FIG. 4, the fixing portion 81 of the torsion shaft reducer 8 may be directly fitted to the spigot portion 53 of the wrist portion 5.

[Advantages of the Invention] As described above, according to the present invention, the step of engaging the spigot part of the wrist with the spigot part at a position offset from the center of the bending drive shaft of the wrist part of the robot arm. A gear shaft driven by a torsion drive shaft is supported concentrically with the attachment part, and a spigot portion concentric with the bending drive shaft is provided to provide a speed reducer housing to which the torsion shaft speed reducer is fixed. Therefore, the gear housing and bevel gear are common, and the coaxial wrist mechanism can be easily switched to the offset wrist mechanism simply by replacing the parts of the input shaft and the reducer housing of the torsion shaft reducer. This has the effect of reducing the number of parts and simplifying production control on the robot production line.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 and FIG.
4 and 5 are side sectional views when switching to the offset wrist mechanism. 1 ... Arm, 2 ... Bending drive shaft, 3 ... Gear housing, 4 ... Bending shaft reducer, 5 ... Wrist part, 51 ... Side mounting part, 52 ... Front mounting part, 53 ... Inlay part, 6
...... Torsion drive shaft, 68 ...... Gear shaft, 7 ...... Reducer housing, 72 …… Stepped part, 73, 74 …… Inlay part, 8 …… Torsion shaft reducer

Claims (1)

[Scope of utility model registration request] 1. A wrist portion (5) capable of rotating about a rotation axis perpendicular to the longitudinal direction of a hollow arm (1) is provided at the tip of the arm (1), and the wrist portion (5) is provided. 5) A bending shaft reducer (4) is provided on a side surface mounting portion perpendicular to the rotating shaft, and a twist shaft is installed on a front surface mounting portion of the wrist portion (5) parallel to the rotating shaft. A wrist mechanism of an industrial robot provided with a speed reducer (8) so as to have at least two degrees of freedom. A bending drive shaft supported inside the arm (1) for rotating the wrist (5). (2) A wrist part (5) provided with a spigot part (53) provided on the front mounting part offset from the center of (2), and a step part (72) fitted to the spigot part (53). ,
The torsion shaft is supported by a gear shaft (68) driven by a torsion drive shaft (6) concentrically with the stepped portion (72) and provided with an inlay portion (74) concentric with the bending drive shaft (2). An industry characterized in that a reduction gear housing (7) to which a shaft reduction gear (8) is fixed, and a transmission device that connects the gear shaft (68) and the torsion shaft reduction gear (8) are provided. Robot wrist mechanism