JP2008286379A - Non-interactive joint mechanism by planetary differential gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-interactive joint which is small, has a wide movable range, and in which one operation amount does not affect other operation amount. <P>SOLUTION: A joint is formed by meshing a pair of spur gears 1a, 1b and a pair of spur gears 2a, 2b which differentially rotate coaxially through a gear for reversing. One of the pairs revolves around the other pair of the spur gears to change an angle of the joint. Thereby, even when the angle of the joint is changed, rotation of the gears is not affected, and the joint, which is not affected by the angle of the joint even when the gear is rotated, can be provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a joint mechanism that transmits power at an arbitrary angle.

  In recent years, an increase in the degree of freedom of operation in a machine such as a robot has demanded a joint mechanism that is small, has a wide range of motion, and is easy to control.

As shown in FIG. 6, the conventional joint mechanism has a multistage connection between a motor and a frame on which the joint is mounted, and each motor drives the joint to move the frame ahead and determine the operation and posture. In this method, since a motor is mounted on each frame, it is difficult to reduce the size, and the closer the motor is, the more the load becomes larger.
In order to solve this, a joint with two degrees of freedom by two motors and a differential mechanism was also made, but since the movement of one motor affects both degrees of freedom, it reproduces the independent movement of each degree of freedom. To do this, the two motors need to be coordinated, making control difficult.

In the present invention, a small-sized joint mechanism that can independently control movements of two degrees of freedom is realized by combining two sets of gears that perform differential rotation.
FIG. 1 shows the configuration of the present invention. Both the power input side 1 and the output side 2 are constituted by differential gears for differential rotation with the spur gears 1a, 1b, 2a, 2b. The input side 1 and the output side 2 are connected by a coupling frame 3 to form a joint. The bevel gear in contact with the spur gear is fixed to the spur gear, and the shaft passing through the spur gear is fixed to the coupling frame 3. The spur gear and the shaft are not fixed.
FIG. 2A illustrates the operation when inputting and outputting from the reversing gear.
When the input shaft 1c is rotated, the spur gears 1a and 1b are reversed to each other, and the spur gears 2a and 2b meshed with the spur gears 1a and 1b are also reversed to take the differential from the output shaft 2c. This operation is performed regardless of the angle of the joint.
FIG. 2B shows an operation for changing the angle of the joint. For example, if the position of the input side 1 is fixed, the output side 2 revolves around the spur gear of the input side 1, and if the size of the spur gear is the same, the coupling frame 3 is half the bending angle of the joint. Rotate at an angle. At this time, since the spur gear is not differentially rotated, the input shaft 1c and the output shaft 2c are not affected by revolution.

As described above, it is possible to realize a non-interfering joint having two degrees of freedom in which power is transmitted from the input shaft to the output shaft and the angle of the joint can be freely changed. Further, by interposing a spur gear in meshing of spur gears, the output shaft can be changed to a joint that is displaced parallel to the input shaft.
Of course, the differential portion may be constituted by only a spur gear, and power may be applied to any gear on the input side or taken out from any gear on the output side.

  The present invention is easy to control because the movement of one degree of freedom does not affect the movement of the other degree of freedom. In addition, it is small and has a wide range of movement, and the arrangement angle of the mechanism and motor can be determined arbitrarily, so the degree of freedom in design is high.

  Since the present invention is easy to be unitized and highly versatile, it can be applied as a joint of various devices. The application example will be described below.

Fig. 3 shows the application to play equipment. When a person on the gondola turns the pedal, power is transmitted to the support through the joint of the present invention. This makes it possible to turn the gondola without using power other than the person on board. Although the angle of the joint changes due to the centrifugal force, the present invention operates without changing the load.
Fig. 4 shows an application to a vehicle leg. By transmitting the power in the body of the vehicle to the wheels through the joints, the unsprung mass can be reduced and the impact absorption effect from the road surface can be enhanced. Further, the power machine is not affected by the displacement due to the impact.
FIG. 5A shows an application to a humanoid robot. It can be used for neck, shoulder, crotch, and ankle joints, which are parts that require movement of two or more degrees of freedom, and can provide two operations: drive of the coupling frame and transmission of power.
FIG. 5B shows a configuration when the present invention is used for a hip joint. The operation of opening the foot sideways and the operation of moving the foot back and forth are performed according to the present invention, and the operation of changing the direction of the toes is performed by a motor mounted on the foot. As shown in the AA ′ cross-sectional view for securing the strength, the output shaft is formed to penetrate, and the shaft passing through the spur gear is not fixed to the coupling frame. In this configuration, the motor can be disposed in a portion close to the trunk, so that the mass of the foot is lightened and a fast operation is possible. Moreover, the movable range is wide, and the deformation of the proportion as a human figure can be reduced.

    It is a block diagram of the present invention.     It is an operation | movement diagram of this invention.     It is a block diagram of the Example of this invention.     It is a block diagram of the Example of this invention.     It is a block diagram of the Example of this invention.     It is a block diagram of the conventional system.

Explanation of symbols

1. Input side 1a, 1b. Spur gear 1c. Input shaft Output side 2a, 2b. Spur gear 2c. Output shaft Combined frame

Claims (1)

  Prepare two sets of two spur gears that rotate differentially on the same axis via a reversing gear, mesh the two sets of spur gears, and one set around the other set of spur gears. The rotation of one set of gears is transmitted to the other set of gears without being affected by the change in the joint angle by changing the angle of the joint by relatively revolving. Interference joint mechanism.

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