BALANCING MECHANISM FOR INDUSTRIAL ROBOT

摘要

PCT No. PCT/JP85/00366 Sec. 371 Date Feb. 20, 1986 Sec. 102(e) Date Feb. 20, 1986 PCT Filed Jun. 28, 1985 PCT Pub. No. WO86/00255 PCT Pub. Date Jan. 16, 1986.The industrial robot comprises a lower arm (13) provided on a robot body (12) pivotably about a first horizontal axis (C1). The lower arm (13) has provided thereon a forearm (14) pivotably about a second horizontal axis (C2). The forearm (14) is rotationally driven by a drive such as a motor (16). The robot body (12) has provided thereon a rotating disk (17) interlocked with the pivoting of the forearm (14) about the second axis (C2) and rotatable about the first axis (C1). Also the rotating disk (17) has secured thereon a first wheel (18) and coaxial therewith, the diameter of which is smaller than that of the disk. There is further provided a tension spring assembly (19) having one end thereof connected to the robot body (12) and which has rotatably mounted at the other end thereof a second wheel (21) having nearly the same diameter as that of the first wheel. Also provided is a chain (22) having one end thereof connected to the rotating disk (17) and the other end engaged on the first wheel (18). This chain (22) is engaged on the outer circumference of the second wheel (21) while pulling the tension spring assembly (19). The one end of the chain (22) is so disposed on the rotating disk (17) that when the upper end of the forearm (14) is directed normally downward, the chain portion (22b) between the rotating disk (17) and the second wheel (21) is substantially parallel to the chain portion (22c) between the first and second wheels (18) and (21).