초록 ▼

A vacuum cleaner having a suction nozzle and a dust bag (12) which is connected to the nozzle, for instance, by a tube connection, and a turbo-fan unit (27) driven by an electric motor and placed after the dust bag seen in the flow direction. The impeller (29) of the turbo-fan unit is driven at a sp

A vacuum cleaner having a suction nozzle and a dust bag (12) which is connected to the nozzle, for instance, by a tube connection, and a turbo-fan unit (27) driven by an electric motor and placed after the dust bag seen in the flow direction. The impeller (29) of the turbo-fan unit is driven at a speed above 50,000 rpm. A primary air stream created by the turbo-fan unit (27) leaves the unit via an outlet (30) to atmosphere. The vacuum cleaner also creates a secondary air stream which at least partially cools the electric motor (32) and which flows into the electric motor via one or several cooling air inlets (44) which are separated from the primary air stream. The secondary air stream can be created by a cooling fan which is separate or integral with the impeller, by a venturi-type nozzle, or by suction created by the impeller. The primary air stream flows in one direction through a channel surrounding a motor shell and the secondary air stream flows in a second, opposite direction through the motor shell and is thereafter redirected and mixed with the primary air stream.

대표청구항 ▼

[ What is claimed is:] [1.] A device for cooling an electric motor for a turbo-fan unit, the motor having a shaft supporting a turbo-fan impeller which is rotatable so as to create a primary air stream which escapes from the turbo-fan unit via an outlet, said device comprising a motor shell having f

[ What is claimed is:] [1.] A device for cooling an electric motor for a turbo-fan unit, the motor having a shaft supporting a turbo-fan impeller which is rotatable so as to create a primary air stream which escapes from the turbo-fan unit via an outlet, said device comprising a motor shell having first and second end walls each having a hub part in which the shaft is supported, and means for creating a secondary air stream which at least partially cools the electric motor and flows into the motor shell through at least one cooling air inlet, said at least one cooling air inlet being separated from the primary air stream and being formed in the second end wall so as to permit the secondary air stream to flow adjacent to the hub part in the second end wall, thereby helping to provide cooling to the hub part in the second end wall.