JPH048492A - Wrist mechanism in robot - Google Patents

Abstract

PURPOSE:To house wiring and piping for a handle or the like in a frame inner part, get rid of redundant cables attendant upon wrist motion, and make disconnection and looseness at each connection, covering breakdown, etc., hard to occur by forming a wrist turning shaft, a wrist bending shaft and a rotary frame into a hollow structure each. CONSTITUTION:A mechanism 3 rotating a rotated body 13 is composed of a hollow structural drive transmission shaft being directly connected to a reduction gear 8 to which this rotated body is directly connected. Wiring and piping are all installed in the hollow part. With this constitution, redundant cables 24 attendant upon, motion of a wrist 2 are brought to nothing, and disconnection and looseness at each connection covering breakdown, etc., are all hard to occur and, what is more, the task range of a robot becomes widened.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a wrist mechanism for a robot.

[Summary of the Invention] The present invention relates to a wrist mechanism of a robot, which can be used in a wrist layer, etc., and can be used in a clean room, etc. to reduce the work area.
In order to eliminate the problem of reduced cleanliness due to wiring and piping being exposed to the outside of the robot arm, the wrist rotation shaft, wrist bending shaft, and rotation frame are made of hollow structure, so that the wiring and piping can be easily removed from the frame. It is designed to be stored inside.

[Prior Art] Conventionally, in the wrist mechanism of a robot, the wiring and piping of signal lines for driving various hands, sensors, etc. attached to the wrist rotation flange are connected to the wrist 30 of the robot, as shown in Fig. 3. 0, which is externally connected to the hand 31, etc., in a manner that allows the robot's wrist to move smoothly and not to adversely affect the surrounding environment such as the robot's work area and the workpiece.
For example, when such a robot arm is used in a clean room, the connection parts of cables such as the wiring 32 and piping 33 are provided with a sealing structure commensurate with the cleanliness level.

[Problems to be Solved by the Invention] In the conventional robot wrist mechanism, the wiring and piping connected from the outside of the robot arm to various hands attached to the wrist rotation flange move in accordance with the movement of the wrist. It needs to be long enough to allow movement. Furthermore, redundant cables are difficult to maintain in a fixed position, significantly narrowing the working range, easily getting caught on other objects, breaking wires, and coming loose at connections, and in dust-proof rooms such as clean rooms. When using robots, internal and external connections, such as double-type connections, require a special seal structure to maintain airtightness of the robot. As described above, it has been desired to attach cables in a manner that does not adversely affect the surrounding area.

[Means for Solving the Problems 1] In order to solve these problems, the present invention provides a wrist mechanism for a robot having at least a rotational degree of freedom and a bending degree of freedom, in which a mechanism for rotating a rotated object is configured such that the rotational object is Consists of a hollow drive transmission shaft that is directly connected to a reduction gear.
This is a robot wrist mechanism that is characterized by the fact that wiring and piping can be installed in the hollow part.

[Function] Wiring and piping connected to various hands etc. attached to the wrist rotation flange by the above-mentioned wrist mechanism,
Since it can be installed inside the hollow rotating frame and the drive transmission shaft for each movement, redundant cables associated with wrist movement are eliminated, and the robot's work area is less prone to disconnections, loose connections, and tearing of the coating. It becomes wider. Furthermore, when used in a robot arm or in a lean room, etc., the airtightness is increased compared to a robot arm in which wiring and piping are exposed outside, resulting in excellent dust resistance and improved cleanliness.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the present invention.

In FIG. 1, the wrist 2 is fixedly attached to the robot arm l. The wrist bending timing belt 17 connected to the wrist bending drive source includes a wrist bending pulley 6,
The rotary frame 3 is configured to be rotationally driven through a wave generator 7 which is a wrist bending shaft that rotates integrally with the pulley 6, and a harmonic speed reduction device 8 that includes a circular spline S18 and a circular spline D19. The wave generator 7, which is a shaft for bending the wrist, is an 8-rotation frame 3 that is supported via a ball bearing 9 so as to be rotatable around the wrist bending axis 4 inside the rotation frame 3, circular spline S18, and circular spline D19. The wrist rotation unit 16, which is supported so as to be rotatable around the wrist bending axis 4 inside the wrist 2 via the roller bearing 10 and the ball bearing 20, is the wrist rotation axis! ! 5, and is rotatable about a wrist bending axis 4 together with the rotating frame 3. Regarding this rotating part 16, the second
This will be explained using figures.

FIG. 2 is a cross-sectional view of the same embodiment as in FIG. 1, viewed from the direction of the wrist bending axis 4 in FIG. In FIG. 2, a motor 11 as a drive source for wrist rotation rotates a flange 14 fixed to the wrist rotation shaft 13 via a wrist rotation shaft 13 that meshes with a harmonic reduction gear 12 and a wrist rotation gear 21. The six wrist rotation gears 21 that are configured to be driven are connected to the rotating frame 3 via roller bearings 22.
It is supported so as to be rotatable around the wrist rotation driving force mechanism axis 23 inside the wrist. The wrist rotation shaft 13 is connected to a gear 8Il in order to transmit the driving force from the wrist rotation gear 21.
ts, 5 rotation frame 3 via roller bearing 15
A motor 11 of a drive source for wrist rotation, which is supported so as to be rotatable around a wrist rotation axis 5 inside the rotation frame 3, is fixed to the rotation frame 3.

Further, the wave generator 7, which is a wrist bending shaft, the wrist rotation shaft 13PI, and the rotating frame 3 have a hollow structure to reduce weight and allow wiring and piping inside. In FIG. 1, the cable 24a is guided through the robot arm l, passes through the hollow part A of the rotating frame 3 through the cable entrance 25 of the rotating frame 3, and further passes through the hollow part A of the wrist rotating shaft 13 and the wrist rotating flange 14. Through the cable inlet/outlet 26, it is connected to various hands 28 etc. attached to the wrist rotating flange. Also, a cable 24 to various sensors 29 etc. attached to the wrist 2
b passes from inside the robot arm l through the hollow part A of the rotating frame 3 and the hollow part C of the wave generator 7, which is a shaft for bending the wrist, and is connected to various sensors 29 and the like through the cable entrance 27.

[Effects of the Invention] As explained above, according to the present invention, the wrist rotation shaft,
The wrist bending shaft and rotating frame have a hollow structure, and the wiring and piping to the hand etc. can be stored inside the frame, eliminating the need for redundant cables associated with wrist movement, reducing the risk of disconnections and connections. It is less likely to loosen or tear the coating, allowing the robot to use a wider working area.

Additionally, compared to models with exposed wiring and piping, there are fewer parts that require sealing, making the robot more airtight and dust-proof. In other words, there are benefits and divination that enable people to handle more complex work and a wide variety of work without having a negative impact on the surrounding environment. Furthermore, the hollow structure reduces the weight of the rotation mechanism, reduces the inertia of the robot tip, and improves positioning accuracy.

[Brief explanation of drawings]

FIG. 1 is a front view of an embodiment according to the present invention viewed from the h side, and FIG. 2 is a sectional view of the same embodiment as FIG. 1 viewed from the side. FIG. 3 is a front view of the conventional example. Robot arm wrist rotation frame Wrist bending axis Wrist rotation axis Wrist bending pulley Wave generator Harmonic reduction gear Ball bearing l O・ ・ 11 ・ 12 ・ ・ 13 ・ ・ 14 ・ ・ 15 ・ ・ l 6 ・ ・ l 7 ・ 18 ・・ 19 ・ 21 ・ 22 ・ ・ 23 ・ ・ 24 ・ ・ 25 ・ ・ 26 ・ 27 ・ ・ 28 ・ 29 ・ ・ ・Roller bearing・Wrist rotation drive source motor Harmonic reduction gear device・Wrist rotation shaft・Flanged roller bearing Wrist rotation part Timing belt for wrist bending Circular spline S Circular spline D Ball bearing is for wrist rotation Gear roller bearing is for wrist rotation Driving force mechanism Axis / Cable Cable entrance / Cable entrance / Cable entrance / Hand / Sensor / Wrist / Hand / Wiring/Piping/Cables and more Applicant: Seiko Electronic Industries Co., Ltd. Agent Patent Attorney: Keisuke Hayashi M

Claims (1)

[Claims] In the wrist mechanism of a robot having at least a rotational degree of freedom and a bending degree of freedom, the mechanism for rotating the rotated object is comprised of a hollow drive transmission shaft directly connected to a reduction gear to which the rotated object is directly connected. The robot's wrist mechanism.