초록 ▼

A low speed alternating current motor having motor shaft speeds of about 300 is provided, and such motor has application in numerous industries and devices, such as, for example, in top drive drilling systems. Because of the low shaft speed, mechanical speed reduction equipment may not be necessary.

A low speed alternating current motor having motor shaft speeds of about 300 is provided, and such motor has application in numerous industries and devices, such as, for example, in top drive drilling systems. Because of the low shaft speed, mechanical speed reduction equipment may not be necessary. In addition, the motor shaft may be hollow to facilitate the flow of fluid, such as, for example, drilling mud.

대표청구항 ▼

What is claimed is: 1. A top drive drilling system, comprising:an electric motor capable of producing sufficient torque to rotate a drill string and a drill bit during drilling operations, wherein the electric motor includes a hollow shaft;a stator assembly comprising a plurality of stator laminates

What is claimed is: 1. A top drive drilling system, comprising:an electric motor capable of producing sufficient torque to rotate a drill string and a drill bit during drilling operations, wherein the electric motor includes a hollow shaft;a stator assembly comprising a plurality of stator laminates compressed into a plurality of stator packs, the stator packs being longitudinally spaced to form radially directed channels for the movement of cooling air or fluid;a rotor assembly comprising a plurality of rotor laminates compressed into a plurality of rotor packs, the rotor packs being longitudinally spaced to form radially directed channels for the movement of cooling air or fluid;a pulse width modulated variable speed drive for generating a signal to drive the electric motor at the desired speed of the drill bit, thereby avoiding speed reduction equipment; anda cooling system of one or more cooling fans with output directed to supply cooling air, said cooling air is passed through the said radially directed channels in said stator and rotor assemblies.