METHOD OF AIR COOLING SECTIONED INVERTER-FED INDUCTION MOTOR AND SECTIONED INVERTER-FED INDUCTION MOTOR EQUIPPED WITH AIR COOLING SYSTEM

摘要

FIELD: electricity.;SUBSTANCE: invention relates to the field of electrical engineering immediately dealing with design of high-capacity sectioned inverter-fed induction motors equipped with closed-circuit forced air cooling systems. In accordance with the invention concept sections (7, 8) of the proposed inverter-fed induction motor are successively cooled with air supplied from the air-cooler (22) by means of a blower (21) with the heated air returned to the air-cooler. Each section is cooled with three air fluxes delivered through the stator and rotor pack slots, stator pack internal cooling ducts and section external cooling ducts. Cooling of all the sections except the last one over, the above air fluxes become mixed in the intersectional chamber (26). Inside the motor housing (1) there is a shaft (6) bearing-mounted. The closed-circuit forced air cooling system is structurally associated with the housing accommodating the motor sections. Each section contains the following components: rotor tooth packs (15, 16) mounted onto the shaft, a framework (9) that has a ring excitation winding (14) fitted inside its bore and stator tooth packs (10, 11) with phase windings (12) laid in their slots. The cooling system comprises the following components: external cooling ducts (25) formed by the housing inside and the outside of each section's framework, finned in the axial direction; internal cooling ducts (29) that communicate via the intersectional chamber (27, 28) and arranged in pairs, axially oriented, under the slots of each section's stator packs; an intersectional mixing chamber (26) and a housing-circuited air duct (20) accommodating a blower and an air-cooler. The external cooling duct is formed with the help of distance pieces (19). The air-cooler is mounted onto the housing. The blower may either be kinematically connected to the motor shaft or have an independent drive.;EFFECT: enhanced efficiency of heat removal from the most thermally-loaded elements of the inverter-fed induction motors, the said elements' operational temperature minimisation and respective improvement of the motor reliability.;6 cl, 2 dwg