ROBOT ARM

• US 20110036188A1
• Filed: 01/21/2009
• Published: 02/17/2011
• Est. Priority Date: 01/22/2008
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Matsukawa, Yoshihiko, Mizuno, Osamu, Okuda, Akinobu, Takahashi, Rie, Tojo, Tsuyoshi, Fujioka, Soichiro, Nakamura, Tohru
• Granted Patent: US 8,286,528 B2
• Time in Patent Office: Days
• US Class Current: 74/405
• CPC Class Codes: B25J 19/0091 Shock absorbers in general F16F
• CPC Class Codes: B25J 19/06 Safety devices
• CPC Class Codes: B25J 9/102 Gears specially adapted therefor, e.g. reduction gears gearings in general F16H
• CPC Class Codes: F16H 35/10 Arrangements or devices for absorbing overload or preventing damage by overload for screw mechanisms F16H25/2021
• CPC Class Codes: Y10T 74/19614 Disconnecting means
• CPC Class Codes: Y10T 74/20305 Robotic arm
• CPC Class Codes: Y10T 74/20329 Joint between elements

Abstract

A robot arm has: a drive gear that has a shaft; a gear frame being capable of turning about the shaft of the drive gear; a first follower gear being capable of turning, in synchronization with the drive gear, about a shaft fixed to the gear frame, in a direction opposite to the turning direction of the drive gear; a transmission control mechanism that is capable of locking the first follower gear to the drive gear; an arm that moves in synchronization with the first follower gear; and a collision detection unit that is capable of detecting a collision between the arm and an obstacle. The transmission control mechanism unlocks the follower gear from the drive gear in response to detection, by the collision detection unit, of collision between the arm and the obstacle.

Claims

1. A robot arm, comprising:

a drive gear that has a shaft;

a gear frame being capable of turning about the shaft of the drive gear;

a first follower gear being capable of turning, in synchronization with the drive gear, about a shaft fixed to the gear frame, in a direction opposite to the turning direction of the drive gear;

a transmission control mechanism being capable of locking the first follower gear to the drive gear;

an arm that moves in synchronization with the first follower gear; and

a collision detection unit that is capable of detecting a collision between the arm and an obstacle, wherein

the transmission control mechanism unlocks the first follower gear from the drive gear in response to the detection, by the collision detection unit, of collision between the arm and the obstacle.

2. The robot arm according to claim 1, wherein the transmission control mechanism has a second follower gear that can assume a lock position of locking or an unlock position of unlocking the first follower gear to/from the drive gear.

3. The robot arm according to claim 2, wherein at the lock position, the second follower gear meshes with both the drive gear and the first follower gear, and at the unlock position, the second follower gear meshes with either the drive gear or the first follower gear.

4. The robot arm according to claim 3, wherein in the transmission control mechanism, the second follower gear can move between the lock position and the unlock position while meshing with at least the drive gear or the first follower gear.

5. The robot arm according to claim 1, wherein when the first follower gear is locked to the drive gear by the transmission control mechanism, the gear frame is set to be able to turn about the shaft of the drive gear, and when the unlocking is effected, the gear frame is locked so as not to turn about the shaft of the drive gear.

6. The robot arm according to claim 1, wherein the first follower gear meshes with the drive gear.

7. The robot arm according to claim 6, further comprising an outer ring gear having inner teeth and being fixed to the arm, wherein

the first follower gear is a planetary gear that can revolve around the drive gear while meshing with the inner teeth of the outer ring gear, and

the outer ring gear can turn in phase with the first follower gear.

8. The robot arm according to claim 7, wherein the transmission control mechanism comprises a clutch section having a movable section fixed to the first follower gear, and a fixed section fixed to the gear frame,

the transmission control mechanism locking the first follower gear to the drive gear by coupling the movable section with the fixed section, and when the collision detection unit detects a collision of the arm the transmission control mechanism unlocking the first follower gear from the drive gear by separating the movable section from the fixed section.

9. A robot arm, comprising:

a drive gear that has a shaft;

a gear frame being capable of turning about the shaft of the drive gear;

a first follower gear being capable of turning, in synchronization with the drive gear, in a direction opposite to the turning direction of the drive gear;

a transmission control mechanism that is capable of locking the first follower gear to the drive gear;

an arm that moves in synchronization with the first follower gear; and

a collision monitoring unit that monitors a collision between the arm and an obstacle, wherein

the transmission control mechanism unlocks the first follower gear from the drive gear when the collision monitoring unit detects a possibility of collision between the arm and the obstacle that stands in a movement direction of the arm.