JPS6322290A - Wrist mechanism of robot for clean room - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an improved structure of a wrist mechanism of an industrial robot.
In particular, the present invention relates to a structure that prevents dust and oil components from leaking out from a wrist mechanism of a clean room robot suitable for use in a clean room maintained in a clean atmosphere.

[Prior art]

As an industrial robot used in a clean room that maintains a clean atmosphere, it prevents the generation of dust from movable parts of the robot, such as the robot body, robot arm, and robot wrist. Clean room robots are available in a variety of structures. These clean room robots are precision products. For example, since it is used for V-building and assembly of integrated circuit components, it is necessary to avoid not only dust but also leakage of oil components of lubricants and greases used in the internal operating mechanism from inside the robot body. In particular, wrist mechanisms and robot hands and other work tools attached to the wrist mechanisms often come close to the precision products they are working on, so they must have reliable dust-repellent structures and oil leakage prevention structures. .

[Problems to be solved]

However, in conventional clean room robots, the robot body is communicated and connected to a negative pressure source consisting of an air suction line to maintain a negative pressure state inside the movable parts. Even if there is a structure that sucks dust into the air suction line and prevents it from leaking into the clean room, this is especially true when the robot wrist has a structure that incorporates actuating means such as a drive source and a speed reducer. Nothing has yet been proposed that can completely prevent the lubricant sealed in the reducer from leaking out through minute gaps in the wrist. Therefore, the present invention aims to solve the above-mentioned problems in the wrist mechanism of a clean room robot in which a reducer containing lubricant is built into the robot wrist.

[Solution]

According to the present invention, in a wrist mechanism attached to the tip of a robot arm of a clean room robot used in a clean atmosphere, the wrist housing is communicatively connected to a negative pressure source, and the wrist operating section is provided at one end of the wrist housing. , comprising a motor provided in the wrist housing to operate the wrist operating section, and wrist operating means having a speed reducer, and a labyrinth seal is provided at the boundary between the wrist housing and the wrist operating section. There is provided a wrist mechanism for a clean room robot characterized by having a structure in which the output end of the reducer of the wrist actuating means is sealed with a grease seal.

[Function] As mentioned above, since a labyrinth seal is provided between the wrist housing that maintains a negative pressure state and the wrist operating part, it is possible to prevent fine dust from flowing from the inside of the wrist to the outside. Since this prevents the oil component from leaking inside the wrist, it also prevents the lubricant component from leaking to the outside. Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

〔Example〕

Now, FIG. 1 is a sectional view of the wrist mechanism of a clean room robot according to the first embodiment of the present invention, FIG. 2 is a side view of the wrist mechanism as seen from the arrow n-n line in FIG. The figure is a front view showing the overall structure of a clean room robot to which this wrist mechanism is attached.

Referring to FIGS. 1 and 2, the wrist machine 118 of the clean room robot has a wrist housing 10, which includes a support 10a, lids 10b and 10C that are tightly fitted to the support 10a. A wrist operating section 20 is provided at one end of the support body 10a, that is, on the front end side.
is held movable, and the other end, that is, the rear end side, is formed as a connection end to a robot arm (not shown in FIG. An opening is formed to communicate with a suction source to obtain a negative pressure state. Reference numeral 14 indicates one of the bolts connecting the robot arm. Further, an electric motor 16 (generally composed of a DC servo motor), which serves as one operation source of the wrist operating section 20, is held on the support 10a, and an electric motor 16 attached to an output shaft 16a of the electric motor 16 is held. Pulley 18
The rotational force is transmitted from a to a pulley 18c via a belt 18b. Drive shaft 22 to which this pulley 18c is attached
forms an input axis for the upward and downward movements of the wrist operating section 20,
A configuration is adopted in which the rotational force transmitted to the drive shaft 22 is transmitted to the internal machine frame 26 of the wrist operating section 2o via the reducer 24. At this time, the internal machine frame 26 rotates relative to the support body 10a around the axis of the drive shaft 22 at a desired deceleration rate. The internal machine frame 26 itself is rotatably held on the support 10a by a bearing 28.3°, the bearing 28 being formed by a well-known cross roller bearing, while the bearing 3o is formed by a grease lubricated ball bearing. Therefore, the grease seal 32 prevents lubricant from leaking.

On the other hand, the bearing 24a of the reducer 24 and the bearing 22 of the drive shaft 22
Although a is also lubricated with grease, leakage is prevented by a grease seal 36 provided at the sliding portion between the outer end of the reducer holder 34 and the pulley 18C. In other words, reducer 2
4. The structure is such that the lubricating grease sealed in the other rotating elements does not leak even inside the wrist mechanism 8, and each of the grease seals 32 and 36 is coated with a resin (tetrafluoroethylene). The grease seal 32 is formed as a sealing member.
and 36 do not generate fine dust due to wear and tear.

Now, in the wrist operating section 20, an internal machine frame 26 forms a first wrist operating section, and a rotation output member 40 that forms a second operating section provided at the tip of the internal machine frame 26 is attached to the drive shaft 22.
The rotation output member 40 is rotatably provided around an axis perpendicular to the axis of the engine, and this rotation output member 40 is driven by an electric motor 42 housed in the internal machine frame 26 to reduce the speed at a desired deceleration rate via a speed reducer 44. The speed reducer 44 is configured to be rotationally driven, and has a bearing 46 lubricated with grease. Further, the rotation output member 40 is rotatably held by a bearing 48. Therefore, grease seals 50 and 52 are arranged on the outside of the bearing 46 and the outside of the bearing 48 to prevent grease from leaking. In addition, a labyrinth 54 is formed in the mutual sliding part of the internal machine frame 26 of the wrist operating unit 20 and the support body 10a during the upward and upward movement, so that a labyrinth 54 is formed from the outside of the wrist toward the inside of the wrist mechanism 8 which is held in a negative pressure state. Since the structure is such that only clean air flows in minute amounts at a time, fine dust and oil components do not leak out from inside the wrist mechanism 8 to the outside. Although not clearly shown in the figure, a labyrinth is similarly formed at the sliding portion between the outer end of the internal machine frame 26 and the inner surface of the rotational output member 40, so that the wrist operating section 20 also has a labyrinth. A fine air flow accompanying a negative pressure effect is formed from the outside of the output member 40 toward the inside of the internal machine frame 26 through the labyrinth, and conversely, fine dust and oil components do not leak from the inside to the outside. It looks like this.

As mentioned above, the present invention basically adopts a structure that fundamentally eliminates the cause of leakage of contaminant dust and oil components from the inside of the wrist mechanism into the outside clean room maintained in a clean atmosphere. It is. Therefore, in addition to eliminating the cause of contamination from inside the wrist mechanism, we also installed wiring from the outer periphery of the robot body, similar to conventional clean room robots.
A configuration that eliminates piping is also adopted. That is, in the present invention, the wiring for the electric motors 16 and 42 is connected to the lid part 10b,
10c is configured to be stored inside the sealed wrist mechanism 8, and as shown in the figure, for example, wiring 60a, 60b for the motor 42 is formed to be connected via a connector 62, and the wiring 60a is connected to the robot 42. The wiring 60b extends through the arm to the robot body and is fixedly wired to the motor 42. Therefore, when mechanically coupling the wrist mechanism 8 to the robot arm, the connector 62 connects the wiring 60a.
and 60b, and the wiring 60a, 6
0b are stored within the wrist mechanism 8. In addition, when coupling or removing the wrist mechanism 8 and the robot arm, the lid parts 10b and 10c are removed from the support body 10a and the mechanical coupling is performed during sushi.
The interlocking connection between 10C and support 10a is suitably sealed with sealing means. In addition, 64 is connected to the rotation output member 40 of the wrist mechanism 8. For example, when connecting an air suction system to create a negative pressure state in a robot hand, etc., the suction line is connected from inside the wrist mechanism 8 to the robot hand. This is a joining frame that allows you to reach. Reference numeral 66 designates a signal connection connector for sending electrical signals to the robot hand and receiving electrical detection signals.

Figure 2 shows the wrist operating section 2 in the wrist mechanism shown in Figure 1.
0 shows a state in which the wrist housing 10 is tilted up and down, and the rear section is a sectional view showing the electric motor 16 for driving the tilting motion.

Further, FIG. 3 shows the wrist mechanism 8 according to the first embodiment described above.
FIG. 2 is a front view showing the overall shape of the clean room robot to which the robot is attached. In FIG. 3, the wrist mechanism 8 is attached to the tip of a robot arm (the tip is slightly shown) that is telescopically housed inside the robot arm 6. It is attached to the upper end of a vertical shaft (the tip is slightly shown) housed inside the robot main body 4. The above-mentioned vertical axis is configured to be able to move up and down as well as to be able to rotate around the vertical axis. Note that the robot main body 4 is fixedly fixed to the floor surface inside the clean runnim. Appropriate robot working means, such as a robot hand, is attached to the rotation output member 40 of the wrist operating section 20 of the rotation output member 8 of the wrist mechanism 8 to accomplish desired robot work in a three-dimensional space.

FIG. 4 is a sectional view showing another embodiment of the wrist mechanism for a clean room robot according to the present invention, and in this embodiment, a single wrist operating section is provided.

This wrist mechanism 8a has a wrist housing 90 of a sealed structure similar to the previous embodiment, and this wrist housing 90 is formed from a support body 92 and a lid body 94, and the support body 92 is used for driving the wrist operating section 100. An electric motor 96 is held. As in the previous embodiment, the wrist operating section 100 is provided at the front end of the wrist housing 90, and the rear end is formed at the end connected to the robot arm. The rotational output of the motor 96 is transmitted to the input bevel gear 102 at a desired deceleration rate via the reducer 98.
The Hergear 104 converts the rotational direction from the output of the wrist operating section 100 to the output of the wrist operating section 100, which is then transmitted to the rotational output member 106 of the wrist operating section 100. Here, 108 is a grease-lubricated bearing provided in the reducer 98, 110 is a bearing of the input beher gear 102, and 11
Reference numeral 2 denotes a bearing for supporting rotation of the rotation output member 106. and a grease seal 114 on each bearing 100.11.
0.112, and is designed to prevent lubricating grease from leaking. Further, a retainer ring 118 is attached to the support body 92 in a sealed manner via an O-ring 116, and is provided to hold the grease seal 114 and the bearing 112. 106
A labyrinth structure is provided in the sliding portion 120 between the two and forms a sealing structure. Therefore, when the inside of the wrist mechanism 8a is maintained in a negative pressure state, the outside of the wrist passes through the labyrinth structure, the small hole 122 formed in the rotation output member 106, and the center hole 124 of the rotation output member 106. A clean air flow is formed toward the inside of the wrist housing 90,
Leakage of fine dust and lubricating grease from the inside of the wrist housing 90 to the outside is prevented. Note that when the wrist mechanism 8a is actually used, a working tool such as a robot hand is attached to the outer end of the rotational output member 106, so the rotational output member 10
The central hole 124 of No. 6 receives a flow of clean air from the outside through only the small hole 122.

FIG. 5 shows the external appearance of a clean room robot to which the wrist mechanism 8a of the second embodiment of the invention described above is attached, and since it has the same configuration as the case of FIG. 3 described above, it will not be described in detail here. omitted.

〔Effect of the invention〕

As is clear from the above description, the present invention employs a structure in which a grease seal is skillfully used in the wrist mechanism of a clean room robot to prevent fine dust and lubricating grease components from leaking from inside the wrist mechanism to the outside. In addition, a labyrinth structure is used to create a slight flow of clean air from the outside toward the inside of the wrist mechanism, which maintains a negative pressure state as in the past, and this also prevents leakage to the outside. Since we provide a robot wrist mechanism that is configured to prevent the above-mentioned problems and has a structure in which wiring and piping are housed inside, it is possible to obtain a wrist mechanism that is extremely suitable for use in a clean room maintained in a clean atmosphere. be. It should be noted that the first and second embodiments described above both employ the well-known harmonic drive device (trade name) as the reducer used in the wrist mechanism according to the present invention, which is connected to the motor. This is because it is suitable for being installed in a narrow space and obtaining a relatively high deceleration rate.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a first embodiment of the wrist mechanism of a clean room robot according to the present invention, FIG. 2 is a side view of the wrist mechanism as seen from the arrow n-n line in FIG. 1, and FIG. FIG. 4 is a sectional view of the second embodiment of the wrist mechanism of the clean room robot of the present invention, and FIG. 5 is a front view showing the overall structure of a clean room robot to which this wrist mechanism is attached. Clean room robot. FIG. 8.8a... Wrist mechanism, IO... Wrist housing, 20... Wrist operating section, 24... Reduction mechanism, 26... Internal machine frame, 40... Rotation output member, 44...・Reducer, 32.36.50.52... Grease seal, 54.
...Labyrinth, 98...Reducer, 114...Grease seal. Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. In a wrist mechanism attached to the tip of a robot arm of a clean room robot used in a clean atmosphere, a wrist housing is communicatively connected to a negative pressure source, and a wrist movement provided at one end of the wrist housing. and a wrist operating means having a motor and a speed reducer provided in the wrist housing to operate the wrist operating section, and a labyrinth is provided at the boundary between the wrist housing and the wrist operating section. A wrist mechanism for a clean room robot, characterized in that the wrist mechanism is sealed with a seal, and the output end of the reducer of the wrist actuating means is sealed with a grease seal. 2. The wrist operating section is connected to the wrist housing in a first direction.
a first operating section that rotates about an axis; and a second operating section that rotates about a second axis with respect to the first operating section, and a boundary between the first and second operating sections. The wrist mechanism for a clean room robot according to claim 1, wherein the wrist mechanism is sealed with a labyrinth seal. 3. According to claim 2, wherein the first operating section is provided with a rotation operating means for the second operating section, and an output end of a reduction gear of the rotation operating means is sealed with a grease seal. wrist mechanism for clean room robots. 4. The wrist mechanism for a clean room robot according to claim 3, wherein the reducer of the wrist actuating means and the reducer of the rotary operation section each include a harmonic drive device.