上海机床厂生产的M7475B型立轴圆台平面磨床的磨头是采用装入式电机直接驱动砂轮的结构形式。电机采用风冷形式,磨头运转时装在电机上部的风扇从磨头顶部的吸风罩口吸入空气后,将空气鼓入电枢及磨头下部进行冷却,然后从磨头后侧的出风口排出。经长期实践证明,此种风冷形式是降低电机及磨头轴承温升的有效方法之一。但由于M7475B型磨床在磨削时采用砂轮 Shanghai Machine Tool Plant M7475B vertical shaft circular table grinding machine grinding head is driven by a built-in motor directly to the wheel structure. The motor adopts the form of air cooling. When the grinding head is running, the fan mounted on the upper part of the motor sucks in the air from the suction hood at the top of the grinding head, then blows the air into the armature and the lower part of the grinding head for cooling, discharge. After long-term practice has proved that this air-cooled form is to reduce the motor and grinding head bearing an effective method of temperature rise. However, because M7475B type grinder grinding wheel