Patent ID: 9687863
Date: 2017-06-27
CPC Classifications: B05B,F16C

Claim:
1. A rotary atomizing head type coating machine comprising: a tubular housing in an inner peripheral side of which a motor accommodating section is formed; an air motor that is accommodated in said motor accommodating section of said housing and rotates a hollow rotational shaft a rotary atomizing head that is positioned on the front side of said housing and is mounted to the front end of said rotational shaft in said air motor to spray paint supplied while rotating together with said rotational shaft; a feed tube that is provided inside said rotational shaft to axially extend with a radial gap to said rotational shaft and supplies the paint to said rotary atomizing head; and a shaping air ring that is provided on the front side of said housing to eject shaping air for arranging a spraying pattern of the paint sprayed from said rotary atomizing head, wherein said air motor includes: a motor case that is formed of a tubular body axially extending and is accommodated in said motor accommodating section of said housing; said rotational shaft that is provided in said motor case to axially extend therein; a turbine that is provided at a base end side of said rotational shaft and rotates said rotational shaft by supply of turbine air thereto; a radial air bearing that is positioned on an outer peripheral side of said rotational shaft and is provided in said motor case to radially support said rotational shaft by supply of bearing air thereto; a front thrust air bearing and a rear thrust air bearing that are provided in said motor case to interpose said turbine therebetween in the front-rear direction to support said rotational shaft in a thrust direction by supply of the bearing air thereto; a turbine air passage that includes an air supply passage for supplying the turbine air to said turbine and an air discharge passage for discharging exhaust air after rotating said turbine; and a bearing air passage that supplies the bearing air to said radial air bearing and said front and rear thrust air bearings, wherein further including: an annular gap space, into which a part of said turbine air and exhaust air discharged from said rear thrust air bearing flow out, is provided between said rotational shaft and said feed tube, and an air outflow hole is provided in said rotational shaft to be positioned between said radial air bearing and said rotary atomizing head and to be radially bored through said rotational shaft, wherein said air outflow hole causes said exhaust air flowing in said annular gap space to flow out outside of said rotational shaft in a position behind said rotary atomizing head.