WRIST APPPARATUS FOR INDUSTRIAL ROBOT

摘要

An industrial robot includes a concentrical triple shaft which consists of a first driving shaft (28), a second tubular driving shaft (27) which concentrically surrounds the first driving shaft (28), a third tubular driving shaft (26) which concentrically surrounds the second driving shaft (27). The robot is further provided with first and second casings (65 and 66). The first casing (65) is pivotal in concentrical relation to the third driving shaft (26). The second casing (66) is pivotally supported by the first casing (65) in such a manner that the axis of rotation of the second casing (66) orthogonally or obliquely crosses the axis of rotation of the first casing (65). Output members (80b, 100, 105) are provided which are pivotally supported by the second casing (66) in such a manner that the axis of rotation of each of the output members orthogonally or obliquely crosses the axis of rotation of the second casing (66). The output members (80b, 100, 105) are driven by the first driving shaft (28). Further, speed governors (73, 80, 106) are disposed on at least one of the power transmission systems in relation to the first and second casings and the output members. Furthermore, bearing boxes (126, 137) are provided which are disposed on the respective outer peripheries of gears (58a, 59) of a gear train constituting each of the power transmission systems in relation to the first and second casings and the output members and which are received in an opening (66d) formed in the casing (66). The opening (66d) in the casing (66) is formed such as to have a diameter larger than that of the outer peripheral portion of each of the gears (58a, 59).