Provided is a robot pivot shaft structure that includes a revolving drum rotatably supported at an upper portion of a base and that has a hollow portion, a drive motor rotating the revolving drum, and a speed reduction mechanism reducing the rotational speed of the drive motor. The speed reduction mechanism has a small gear fixed to a shaft of the drive motor, a large gear meshed with the small gear, an input hypoid gear fixed to the large gear, and an output hypoid gear meshed with the input hypoid gear. The output hypoid gear is fixed to the revolving drum and is disposed in the base. The input hypoid gear and the large gear are rotatably supported at the base. The drive motor is fixed to the base and disposed below the revolving drum, the position being horizontally shifted from vertically below the hollow portion.

A robot arm comprising a joint mechanism for articulating one limb relative to another limb about two non-parallel rotation axes, the mechanism comprising: an intermediate carrier attached to a first one of the limbs by a first revolute joint having a first rotation axis and to a second one of the limbs by a second revolute joint having a second rotation axis; a first drive gear disposed about the first rotation axis and fast with the carrier, whereby rotation of the carrier relative to the first limb about the first rotation axis can be driven; a second drive gear disposed about the second rotation axis and fast with the second one of the limbs, whereby rotation of the second one of the limbs about the second rotation axis relative to the carrier can be driven; at least one of the first and second drive gears being a sector gear.

A robot arm comprising a joint mechanism for articulating one limb relative to another limb about two non-parallel rotation axes, the mechanism comprising: an intermediate carrier attached to a first one of the limbs by a first revolute joint having a first rotation axis and to a second one of the limbs by a second revolute joint having a second rotation axis; a first drive gear disposed about the first rotation axis and fast with the carrier, whereby rotation of the carrier relative to the first limb about the first rotation axis can be driven; a second drive gear disposed about the second rotation axis and fast with the second one of the limbs, whereby rotation of the second one of the limbs about the second rotation axis relative to the carrier can be driven; at least one of the first and second drive gears being a sector gear.

Provided is a robot arm including an upper arm, a forearm installed at the distal end of the upper arm, a wrist element installed at the distal end of the forearm to be rotatable around an axis line and having a hollow part through which the axis line penetrates, a motor installed in the forearm and rotating the element around the axis line, and a mechanism transmitting rotation of the motor to the element while reducing speed of rotation. The motor includes a rotation center axis extending obliquely downward on the opposite side of the upper arm. The mechanism includes a hypoid gear set including an output hypoid gear fixed to the element coaxially with the axis line and an input hypoid gear, and a gear set including a gear wheel fixed to the input hypoid gear and a pinion fixed to the motor.

A robot arm comprising a joint mechanism for articulating one limb (310) of the arm relative to another limb (311) of the arm about two non-parallel rotation axes (20, 21), the mechanism comprising: an intermediate carrier (28) attached to a first one of the limbs by a first revolute joint having a first rotation axis and to a second one of the limbs by a second revolute joint having a second rotation axis; a first drive gear (33) disposed about the first rotation axis and fast with the carrier, whereby rotation of the carrier relative to the first limb about the first rotation axis can be driven; a second drive gear (37) disposed about the second rotation axis and fast with the second one of the limbs, whereby rotation of the second one of the limbs about the second rotation axis relative to the carrier can be driven; at least one of the first and second drive gears being a sector gear.

A robot arm according to the present invention includes: a shoulder joint assembly which is connected to an upper arm portion, and includes a drive unit for generating driving power; an elbow joint assembly which is provided between the upper arm portion and a forearm portion, and operates by being supplied with driving power from the drive unit; and a wrist joint assembly which is provided between the forearm portion and a hand portion, and operates by being supplied with driving power from the drive unit.

A robot arm comprising a joint mechanism for articulating one limb of the arm relative to another limb of the arm about two non-parallel rotation axes, the mechanism comprising: an intermediate carrier attached to a first one of the limbs by a first revolute joint having a pitch rotation axis and to a second one of the limbs by a second revolute joint having a yaw rotation axis; a first drive gear disposed about the pitch rotation axis, the first drive gear being fast with the carrier; a second drive gear disposed about the yaw rotation axis, the second drive gear being fast with the second one of the limbs; a first drive shaft for driving the first drive gear to rotate about the pitch rotation axis, the first drive shaft extending along the first one of the limbs and having a first shaft gear thereon, the first shaft gear being arranged to engage the first drive gear; a second drive shaft for driving the second drive gear to rotate about the yaw rotation axis, the second drive shaft extending along the first one of the limbs and having a second shaft gear thereon; and an intermediate gear train borne by the carrier and coupling the second shaft gear to the second drive gear.

A robot arm comprising a joint mechanism for articulating one limb of the arm relative to another limb of the arm about two non-parallel rotation axes, the mechanism comprising: an intermediate carrier attached to a first one of the limbs by a first revolute joint having a first rotation axis and to a second one of the limbs by a second revolute joint having a second rotation axis; a first drive gear disposed about the first rotation axis, the first drive gear being fast with the carrier; a second drive gear disposed about the second rotation axis, the second drive gear being fast with the second one of the limbs; a first drive shaft for driving the first drive gear to rotate about the first rotation axis, the first drive shaft extending along the first one of the limbs and having a first shaft gear thereon, the first shaft gear being arranged to engage the first drive gear; a second drive shaft for driving the second drive gear to rotate about the second rotation axis, the second drive shaft extending along the first one of the limbs on a first side of a plane containing the second rotation axis and extending through that plane to the second side of that plane; and an intermediate linkage that meshes with the second drive shaft on the second side of the plane and that couples the second shaft gear to the second drive gear.

A robot arm comprising a joint mechanism for articulating one limb of the arm relative to another limb of the arm about two non-parallel rotation axes, the mechanism comprising: an intermediate carrier attached to a first one of the limbs by a first revolute joint having a first rotation axis and to a second one of the limbs by a second revolute joint having a second rotation axis; a first drive gear disposed about the first rotation axis, the first drive gear being fast with the carrier; a second drive gear disposed about the second rotation axis, the second drive gear being fast with the second one of the limbs; a first drive shaft for driving the first drive gear to rotate about the first rotation axis, the first drive shaft extending along the first one of the limbs and having a first shaft gear thereon, the first shaft gear being arranged to engage the first drive gear; a second drive shaft for driving the second drive gear to rotate about the second rotation axis, the second drive shaft extending along the first one of the limbs and having a second shaft gear thereon, the second shaft gear being arranged to engage the second drive gear; the second drive shaft comprising a prismatic joint whereby the length of the shaft can vary in response to motion of the carrier about the first axis.

A robot arm comprising a joint mechanism for articulating one limb relative to another limb about two non-parallel rotation axes, the mechanism comprising: an intermediate carrier attached to a first one of the limbs by a first revolute joint having a first rotation axis and to a second one of the limbs by a second revolute joint having a second rotation axis; a first drive gear disposed about the first rotation axis and fast with the carrier, whereby rotation of the carrier relative to the first limb about the first rotation axis can be driven; a second drive gear disposed about the second rotation axis and fast with the second one of the limbs, whereby rotation of the second one of the limbs about the second rotation axis relative to the carrier can be driven; at least one of the first and second drive gears being a sector gear.