초록 ▼

An improved robotic arm which is capable of accurately manipulating a testing device beneath the tube sheet of the steam generator and accurately and consistently return to a selected tube location is provided. The robotic arm includes a base which is adapted to be fixedly secured to a support beam

An improved robotic arm which is capable of accurately manipulating a testing device beneath the tube sheet of the steam generator and accurately and consistently return to a selected tube location is provided. The robotic arm includes a base which is adapted to be fixedly secured to a support beam which initially positions the robotic arm within the steam generator, a first extension arm which is rotatably mounted on the base forming a primary rotation joint and which extends essentially parallel to the tube sheet. A second extension arm is rotatably mounted at the end of the first extension arm forming a secondary rotation joint and further extends therefrom. The testing device such as an eddy current inspection tool is positioned at a distal end of the second extension arm. The improvement includes a direct drive high-torque DC motor and a harmonic drive coupling being provided at each of the joints for providing a significant reduction ratio between the output of the high-torque DC motor and the rotational joint. Further, these components are of a light weight construction so as to limit the load carried by the robotic arm. A control device is provided for simultaneously independently controlling the high-torque DC motors such that the testing device can be both accurately and reliably positioned relative to the tube sheet. The robotic arm is also capable of being readily adjusted to be used in servicing various models of steam generators.

대표청구항 ▼

A robotic positioning arm for accurately positioning a tool relative to a tube sheet in a nuclear steam generator comprising; a base adapted to be fixedly secured to an initial positioning means; a first extension arm rotatably mounted at a first end thereof on said base and extending therefrom; a f

A robotic positioning arm for accurately positioning a tool relative to a tube sheet in a nuclear steam generator comprising; a base adapted to be fixedly secured to an initial positioning means; a first extension arm rotatably mounted at a first end thereof on said base and extending therefrom; a first drive means for rotating said first extension arm relative to said base including a first high-torque DC motor coupled with a first harmonic drive for reducing the rotation output of said first DC motor by a first predetermined reduction ration and effecting rotation of said first extension arm; a second extension arm rotatably mounted at a first end thereof on a second end of said first extension arm and extending therefrom and having the tool mounted at a second end thereof; a second drive means for rotating said second extension arm relative to said first extension arm including a second high-torque DC motor coupled with a second harmonic drive for reducing a rotational output of said second DC motor by a second predetermined reduction ratio and effecting rotation of said second extension arm; a lifting linkage pivotally mounted on said second extension arm including a mounting bracket secured to a distal end of said linkage for supporting the tool, and a drive means for accurately moving said linkage including an electric motor, a follower connected to said linkage and a leadscrew connected to the output of the motor and threadedly engaged to said follower, and a control means for independently controlling said first and second drive means for accurately positioning the tool relative to the tube sheet in the nuclear steam generator, including first and second positioning sensors for determining a rotational position of said first and second joints, respectively, wherein both said first and second extension arms are disposed horizontally, and each of said joints includes a clutch means disposed between the output of the harmonic drive and its respective extension arm to minimize damage to the joint in the event that its respective arm should meet an obstruction during the operation of the drive means.