JP2014233817A - Concentric biaxial robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple and compact drive transmission mechanism in a robot manipulator that dispenses with rotary positioning at an angle of 360 degrees or more and the output axes of which are two or more concentric axes.SOLUTION: In a robot manipulator, the output axes of which are two or more concentric axes, an output rotary shaft of a rotary driving source is serially arrayed coaxially with the output axis, and power of the rotary driving source in a position far from the output axis is transmitted by an arm assuming a crank shape avoiding the rotary driving source on the side close to the output axis.

Description

  The present invention is applied to a horizontal articulated robot manipulator that performs substrate transfer and assembly operations.

  In the industry, a transfer robot having two degrees of freedom in the same plane is widely used. These robots are classified and called horizontal articulated robots or the like according to the arm structure.

For example, among semiconductor manufacturing apparatuses, what is called a cluster type is widely used for the transfer of a substrate such as a silicon wafer.
In these apparatuses, the transfer robot is installed in the center of the apparatus, and a plurality of transfer target positions are arranged radially on the horizontal plane as viewed from the transfer robot. When the robot transports the board, the arm is extended, the board is loaded on the hand part at the tip of the arm, the arm is contracted, turned, the arm is extended and positioned toward the next transport destination, and the board is installed at the transport destination. It is carried out. The substrate is loaded or installed on the hand unit by the robot body moving up and down, or by lifting and lowering the lifter mechanism at the transfer destination.

  A method for realizing this is described in the following document, for example.

No. 2563403 Patent No. 3863671 (P38663671) JP-A-2-292153

Hiroshi Makino "Robot Mechanism", Nikkan Kogyo Shimbun, 1988

The above-described horizontal articulated transfer robot is usually designed so that the degree of freedom in the turning direction is as close as possible to 360 degrees or more, or 360 degrees, in order to improve versatility.
However, the turning operation angle is not necessarily required to be 360 degrees or more. For example, even in a cluster type semiconductor manufacturing apparatus, there may be a case where only two points at both ends of which the turning angle during conveyance is within 180 degrees are required. In some cases, the turning angle at the time of conveyance may be only 2 points at both ends within 180 degrees and a total of 3 intermediate points.
The present invention is intended to realize a reasonable and high-performance transfer robot by narrowing down the target to an application that does not necessarily require a turning operation close to or more than 360 degrees.

    Further, as a robot for positioning in a horizontal plane, there is a robot that realizes a concentric biaxial mechanism for horizontal positioning by arranging horizontal positioning actuators as shown in Japanese Patent Application Laid-Open No. 2004-228561 in a vertically opposed manner. For example, in a transfer robot in a vacuum environment as shown in Patent Document 2, a magnetic fluid seal is installed between a vacuum chamber in which a robot arm is housed and an actuator. In this case, two rotary seal units for introducing vacuum into the upper and lower wall surfaces of the vacuum chamber are required in two places, which causes complexity and maintenance of the vacuum chamber, which is often not preferable.

  The present invention relates to a robot manipulator in which a horizontal multi-joint type robot arm is attached with a concentric arm attachment output shaft, and the two rotational drive sources and the output shaft thereof are the same as the arm attachment output shaft described above. The most important feature is that it is arranged in series on the shaft and the rotational power of one rotary actuator is transmitted by a crank-shaped arm to avoid interference with the rotary drive source installed on the side close to the output shaft And

  The present invention is characterized in that a turning operation range is limited to less than 360 degrees, and a concentric two-axis output shaft mechanism is configured without using a hollow actuator.

As a method of disposing the rotation drive source on the same rotation axis without using the rotation drive source as a hollow structure, there is a method of installing one rotation drive source in a series on a movable part of the other rotation drive source. However, this method requires separate wiring for the movable cable for simultaneously operating the electric cables of the rotational drive source installed in the movable part, which causes a decrease in reliability.

Therefore, if the rotational drive source can be installed and fixed on the non-movable part of the transport robot, the electric cables connected to the rotational drive source can be made non-movable, and reliability is improved.

  Conventionally, a method has been adopted in which one actuator has a hollow structure and the rotational force of the other actuator is transmitted through the hollow portion. However, generally, actuators having a hollow structure are relatively expensive, and variations are not abundant.

Therefore, in the present invention, the turning angle is limited to less than 360 degrees, two rotational drive sources and their output shafts are arranged in series on the same axis as the aforementioned arm mounting output shaft, and the rotational power of one rotational actuator is provided. Is transmitted by a crank-shaped arm for avoiding interference with a rotational drive source installed on the side close to the output shaft.

This method eliminates the need for the rotary drive source to have a hollow structure. In addition, since transmission of rotational power by a highly rigid member can be realized, drive transmission by a belt having relatively low transmission rigidity is also unnecessary. Further, it is not necessary to transmit a drive by a gear that is a concern about backlash.

FIG. 1 is an explanatory view showing an embodiment (arm extended state) of the present invention. Example 1 FIG. 2 is an explanatory view showing an embodiment (arm contracted state) of the present invention. Example 1 FIG. 3 is an explanatory view showing an embodiment of the present invention (the state in which FIG. 2 is turned). Example 1 FIG. 4 is an explanatory view showing an outline of the arm mounting output shaft portion of the first embodiment and the second embodiment of the present invention. (Example 1 and Example 2) FIG. 5 is an explanatory diagram simply showing the structure of the first embodiment. Example 1 6 shows the robot arm It is explanatory drawing which showed simply what provided the function similar to Example 1 using the mechanism shown by FIG.

  In a robot manipulator in which a horizontal articulated type two-degree-of-freedom robot arm is mounted and two arm mounting output shafts are concentric, the two rotational drive sources and their output shafts are the same as the arm mounting output shafts described above. The structure is arranged in series on the shaft, and the rotational power of one rotary actuator is transmitted by a crank-shaped arm for avoiding interference with a rotary drive source installed on the side close to the output shaft.

  1 to 5 show Embodiment 1 of the device of the present invention. 1 to 3 show the difference in state when the configuration of the same embodiment operates. Reference numeral 11 denotes a circular thin object to be conveyed by operating a robot arm having a horizontal articulated structure. In this embodiment, the robot main body does not have an elevating mechanism that moves up and down, and 11 transfer objects are delivered by a lifter mechanism installed at the transfer destination.

    The robot arm of the present embodiment has a general horizontal articulated arm configuration. Although detailed description of the mechanism is omitted, when the arm connecting output shaft 1 and the arm connecting output shaft 2 are operated at the same angular velocity, the turning operation is performed, and the arm connecting output 3 is output. When the shaft 1 is not operated and the 4 arm connecting output shaft 2 is operated, the robot arm performs an expansion / contraction operation.

FIG. 1 shows a posture state in which the robot arm is extended. FIG. 2 shows a state in which the position of the end effector of 12 robots is contracted by fixing the output shaft 1 for connecting 3 arms and operating the output shaft 2 for connecting 4 arms from the state of FIG. Is shown.

In FIG. 3, the arm connecting output shaft 1 and the arm connecting output shaft 2 are operated at the same angular velocity from the state shown in FIG. 2, so that the arm is not expanded and contracted. Is shown.

    As shown in FIG. 1 to FIG. 3, two rotational drive sources (electric servomotors) 1 and 7 and 8 electric servomotors 1 and fixing frames 1 and 2 are 5 Thus, the robot arm can be expanded and contracted and swiveled without interfering with the detour crank-shaped arm.

    Further, according to the present embodiment, the three arm connection output shafts 1 and the four arm connection output shafts 2 can realize concentric coaxial. In FIG. 1 to FIG. 3, for easy explanation, the turning angle is described as approximately 90 degrees. However, in the case of the shape of the present embodiment, the turning angle can be realized as 180 degrees or more. If optimized, a 270 degree turn is also possible.

  FIG. 4 simply shows the bearing units 52 and 53 for supporting the arm on the arm connecting output shaft shown in FIGS.

In the first embodiment described above, the environment in which the robot is used is not referred to. However, as shown in FIG. 4, if the rotary seal mechanisms 104 and 105 are used in combination, a pressure difference or airtight environment such as a vacuum environment or an airtight isolation environment can be used. It is possible to separate the installation locations of the robot arm and the actuator in environments with different sections.

In this embodiment, it is assumed that the upper part of FIG. 4 is a vacuum environment and the lower part is an atmospheric pressure environment, and the robot arm part is installed in a vacuum environment and the actuator part is installed in an atmospheric pressure environment.
The rotary seal mechanism can be used not only for the purpose of blocking spaces with different pressure atmospheres such as vacuum and atmospheric pressure, but also for the purpose of blocking and isolating a clean atmosphere and a less clean atmosphere. .

  An actuator unit that drives a robot arm capable of extending and retracting in a horizontal plane and turning can be provided, and can be used as a robot for handling semiconductor manufacturing equipment, biotechnology, pharmaceuticals, and the like.

1 Rotation drive source (electric servo motor) 1
2 Rotation drive source (electric servo motor) 2
3 Arm connection output shaft 1
4 Arm connection output shaft 2
5 Electric Servo Motor No. 1 Detour Crank-Shaped Arm 6 Mounting Fixing Flange 7 Electric Servo Motor No. 1 Fixing Frame No. 1
8 Electric servo motor part 1 Fixing frame part 2
9 Arm 2
10 Arm 1
DESCRIPTION OF SYMBOLS 11 Conveyance object 12 End effector 20 Arm attachment output shaft part 51 Power transmission coupling 52 Ball bearing 53 Ball bearing 101 Arm connection output shaft 2
102 Output shaft for arm connection 1
104 Magnetic fluid seal 2
105 Magnetic fluid seal 1
106 O-ring 107 Bearing case 108 Center axis of rotation

Claims (5)

In a robot manipulator drive unit having two degrees of freedom in the same plane, an arm connection output shaft having two concentric rotation shafts for mounting a robot arm, and output rotation shafts of two rotation drive sources for driving them Are arranged on the same axis, the arm connection output shaft 1 for attaching the robot arm is a hollow shaft, connected to the shaft passing through the hollow portion, and the other arm connection output shaft 2 is arranged. Both of the two rotational drive sources are installed in the non-movable part of the transfer robot, and the rotational drive source 2 for driving the arm connection output shaft 2 for attaching the robot arm is the other rotational drive source. The rotary drive source 1 that is installed closer to the arm connection output shafts 1 and 2 than the first and drives the arm connection output shaft 1 is an arm connection output shaft. For driving and characterized in that it is transmitted by the bypass transmission member bypassing the rotary drive source part 2, the robot manipulator having a concentric biaxial drive mechanism. The frame on which the rotary drive source 1 is installed and fixed has a position and shape encompassing the outer shape of the rotary drive source 2 and this frame is appropriately cut so as not to interfere with the operation of the bypass transmission member. The robot manipulator according to claim 1, wherein a notch release portion is provided. 3. The robot manipulator according to claim 1, wherein an electric motor having a positioning function is used for the rotation drive source 1 and the rotation drive source 2 described above. During rotation operation for use in an environment where the pressure is different at both ends of the arm connection shaft 1 and the arm connection shaft 2 described above, or in an environment where one is at atmospheric pressure and the other is in a vacuum environment. However, the robot manipulator according to any one of claims 1, 2, and 3, which incorporates a rotary seal member for maintaining airtightness. Both ends of the arm connection shaft 1 and the arm connection shaft 2 described above are used under operating conditions where the cleanliness of the atmosphere is different, and therefore a rotation sealing member for maintaining airtightness even during rotation operation. The robot manipulator according to claim 1, 2, or 3.

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