Patent ID: 8534153

Claim:
A robot arm assembly, comprising: a first arm; a second arm connected to the first arm; a third arm extending through the second arm; a first transmission assembly received within the first and the second arms; a second transmission assembly received within the first and the second arms; the first transmission assembly comprising: a first rotation shaft comprising a first bevel gear portion; a second rotation shaft comprising a second bevel gear portion engaging with the first bevel gear portion, the second rotation shaft being substantially perpendicular to the first rotation shaft; a third rotation shaft non-rotatably connected to the second rotation shaft coaxially, the third rotation shaft comprising a third bevel gear portion distal from the second rotation shaft; and a bevel gear non-rotatably sleeved on the third arm and engaging with the third bevel gear portion; the second transmission assembly comprising a forth rotation shaft and a fifth rotation shaft, wherein the forth rotation shaft is rotatably sleeved on the first rotation shaft and comprises a forth bevel gear potion, the fifth rotation shaft is rotatably sleeved on the second rotation shaft and comprises a fifth bevel gear portion engaging with the forth bevel gear portion, an end of the fifth rotation shaft opposite to the fifth bevel gear portion connected to the second arm fittingly; and a cover detachably covering a part of the second arm where the third bevel gear portion is engaged with the bevel gear.