求翻译：3、电机。开发初期，基本采用单电机双风道结构，电机采用含油轴承的也较多。后来又发展为双电机双风道，并占据了吸油机市场的大部分份额。但单电机单风道深箱型从开发初期就始终占有一定比例，到目前，这种机型已占有相当大的比例。因为含油轴承的使用寿命较短，于是一端为含油轴承、另一端为滚珠轴承的风行了较长时期，目前基本为滚珠轴承结构，重点厂家均采用了日本的滚珠轴承，其噪音均控制在较低的范围，达到了低噪音的要求。是什么意思？

3, the motor. Early development, the basic single-motor dual-duct structure, the use of oil-bearing motor is greater. Later developed for the dual-motor dual-duct, and occupied the lion's share of oil machine market. However, single-motor single duct box from deep on the early development occupies a

3, electric motor. early stages of development, the basic use of single-electric double-windpath structure used motor oil bearings, the more. Subsequently, development in the double-electric double-totalling 28.35 suction machine, and occupied the lion's share of the market. But single electric sing

3rd, electrical machinery.The development initial period, uses the single electrical machinery double air flue structure basically, the electrical machinery uses the oil-retaining bearing to be also many.Afterwards developed for the double electrical machinery double air flue, and occupied has attra

3 motor. The initial stage, the basic structure of single motor dual-ducts, using more oil-impregnated bearings. Later development of dual motor dual-ducts, and accounted for the lion's share of the oil market. Single motor single channel deep box-from the initial stage has always possessed a certai

3, the motor. Early development, the basic single-motor dual-duct structure, the use of oil-bearing motor is greater. Later developed for the dual-motor dual-duct, and occupied the lion's share of oil machine market. However, single-motor single duct box from deep on the early development occupies a