| 摘要 |
491,923. Motors. SIEMENS-SCHUCKERTWERKE AKT.-GES. March 9, 1937, Nos. 6915 and 6916. Convention dates, March 9, 1936 and Oct. 14, 1936. [Class 35] Cores ; cooling.-In a motor to be run for considerable periods at a substantially constant load the ratio of the output coefficient to the rotor diameter is given by curves according to Figs. 1 and 2 (not shown), the effective rotor length is between 1À3D and 2À7D, where D is the rotor diameter, and preferably between 1À6D and 2À3D: furthermore other dimensions are as follows; for a four-pole machine the stator outer diameter is between 1À5D and 1À8D, preferably between 1À65D and 1À75D and the slot depth is between À17D and À22D; for a six-pole machine the stator outer diameter is between 1À4D and 1À7D, preferably between 1À52D and 1À6D, and the stator slot depth is between À15D and À2D; for an eight-pole machine the stator outer diameter is between 1À3D and 1À5D, preferably between 1À4D and 1À45D, and the stator slot depth is between À12D and À16D; in all cases the product of the number of stator slots and the slot width is between 2D and 2À3D. The diameter of the rotor shaft, is between À56D and À43D for four-pole machines, between À5D and À4D for six-pole machines, and between À45D and À36D for eight-pole machines. The product of the rotor slot width and the number of rotor slots is between 1À45D and 1À55D for four-pole machines, between 1À48D and 1À58D for six-pole machines, and between 1À5D and 1À6D for eight-pole machines, the rotor slot depth being between À125D and À132D. The theoretical basis of these ratios is discussed in the Specification. The Figure shows an enclosed motor constructed according to the invention, and more particularly the cooling- . arrangements therefor. External air is forced by a fan 9 between cooling-channels 8 through which the internal air is forced by a fan 10 returning through the rotor slots and behind the stator. At the back of the stator are arranged guide plates 14 so that the velocity of the air increases gradually to a maximum at the middle of the stator and eddy currents are diminished.
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