| 摘要 |
PURPOSE:To perform cooling efficiently by making air lead-in holes radially through a cylindrical rotary shaft inserted with a ball screw shaft screwed to a ball screw and supplying air between the rotary shaft and the ball screw shaft through an air lead-in hole of housing. CONSTITUTION:A rotary shaft 20 secured with a rotor 18 is formed of a hollow cylinder, then a ball screw shaft 24 is inserted into the hollow section thus forming a penetration motor. The cylindrical shaft 20 is born rotatably by means of front and rear bearings 16, 42, and secured to a ball nut 22 at one end of the motor. The ball screw shaft 24 advances/retracts as shown by an arrow A through rotation of the rotor 18 and the cylindrical shaft, thus moving a driven body. Stator 10 is provided with a winding 26 and supported by means of front and rear housings 12, 14, where a hole 28 for leading air from a compression air source (not shown) is made through the front housing 12. A plurality of air lead-in holes 30 are made radially through the front housing 12. Since the air flows as shown on the drawing upon rotation of the motor and discharged from the opposite end of the motor, the motor is cooled efficiently. |
