A dust collector is provided, which includes a housing, a filter screen, and a spiral air director. The housing is provided with an air inlet, an air inlet channel, an air outlet channel, an air outlet, and a dust collection chamber. The dust collection chamber is in communication with the air inlet and the air outlet through the air inlet channel and the air outlet channel, respectively. The filter screen is disposed in the air outlet channel. The spiral air director is disposed in the air outlet channel and located on at least one side of an air inlet side and an air outlet side of the filter screen. Air flow flowing through the air outlet channel is directed by the spiral air director to form a swirling air flow.

A power supply arrangement for a suction device is provided, which is optionally operable using direct current or alternating current, including a first connection connectible to a direct current source, a second connection connectible to an alternating current source, a third connection connectible to a consuming unit of the suction device, an electrically isolated converter connected on the input side to the first connection, and a switchover device connected to an output of the converter, the second connection and to the consuming unit, wherein the switchover device allows selection of whether the consuming unit is actively connected to the converter or the second connection for power supply, and wherein the switchover device has one or more components each with an electrical safety clearance that is at least 4 mm in respect of the creepage distance and the total of the creepage distances of the components is at least 8 mm.

A power supply arrangement for a suction device is provided, which is optionally operable using direct current or alternating current, including a first connection connectible to a direct current source, a second connection connectible to an alternating current source, a third connection connectible to a consuming unit of the suction device, an electrically isolated converter connected on the input side to the first connection, and a switchover device connected to an output of the converter, the second connection and to the consuming unit, wherein the switchover device allows selection of whether the consuming unit is actively connected to the converter or the second connection for power supply, and wherein the switchover device has one or more components each with an electrical safety clearance that is at least 4 mm in respect of the creepage distance and the total of the creepage distances of the components is at least 8 mm.

A robot cleaner is provided that may include a suction motor installed within a main body to generate a suction force, at least two conductive plates spaced apart from each other to form a flow path for external air introduced by the suction force, and a calculator to measure a capacitance value between the at least two conductive plates. Further, provided is a robot cleaner that may include a suction motor installed within a main body to generate a suction force, a porous structure having at least one through hole, through which external air introduced by the suction force may flow, at least one filter disposed on a surface of the porous structure to filter dust contained in the air, and a power supply configured to apply alternating current (AC) power to at least a portion of the surface of the porous structure.

A robot cleaner is provided that may include a suction motor installed within a main body to generate a suction force, at least two conductive plates spaced apart from each other to form a flow path for external air introduced by the suction force, and a calculator to measure a capacitance value between the at least two conductive plates. Further, provided is a robot cleaner that may include a suction motor installed within a main body to generate a suction force, a porous structure having at least one through hole, through which external air introduced by the suction force may flow, at least one filter disposed on a surface of the porous structure to filter dust contained in the air, and a power supply configured to apply alternating current (AC) power to at least a portion of the surface of the porous structure.

A surface cleaning apparatus comprises an air treatment member having a first end, a longitudinally spaced apart second end, an air inlet and an air outlet comprising an outlet conduit; an air flow path extending from a dirty air inlet to a clean air outlet and including a suction motor and the air treatment member; a pre-motor filter positioned in the air flow path downstream from the outlet conduit; and, an agitation member operatively engageable with the pre-motor filter.

A vacuum cleaner, including a cleaner body; and a dust collector provided in the cleaner body, wherein the dust collector includes a first cyclone provided within an outer case to filter foreign matter and dust from air introduced into the dust collector; a second cyclone accommodated within the first cyclone to separate fine dust from the air introduced into the first cyclone; and a screw surrounding part of the first cyclone, and configured to be rotatable in at least one direction with respect to the first cyclone, wherein the screw includes a pillar that spans a height of the mesh filter; and a scraper provided on an inner surface of the pillar facing an outer surface of the mesh filter, and configured to sweep off dust and foreign matter accumulated on the mesh filter during the rotation of the screw.

A vacuum cleaner, including a cleaner body; and a dust collector provided in the cleaner body, wherein the dust collector includes a first cyclone provided within an outer case to filter foreign matter and dust from air introduced into the dust collector; a second cyclone accommodated within the first cyclone to separate fine dust from the air introduced into the first cyclone; and a screw surrounding part of the first cyclone, and configured to be rotatable in at least one direction with respect to the first cyclone, wherein the screw includes a pillar that spans a height of the mesh filter; and a scraper provided on an inner surface of the pillar facing an outer surface of the mesh filter, and configured to sweep off dust and foreign matter accumulated on the mesh filter during the rotation of the screw.

A vacuum cleaner filtration system having a primary separation system and a filter downstream of the primary separation system. The filter has an upstream side to receive an airflow exiting the primary separation system, and a downstream side fluidly opposite the upstream side. The system has a vacuum fan, a primary suction path between the filter's downstream side and the vacuum fan, a valve in the primary suction path and configured to selectively position to block the primary suction path and create a closed passage at the filter's downstream side, and a secondary suction path between the filter's upstream side and the vacuum fan. A secondary filtration system is in the secondary suction path to separate dirt from an airflow passing therethrough, to thereby clean dirt from the filter's upstream side. A nozzle may be provided to concentrate the air flow as it enters the secondary suction path.

A vacuum cleaner filtration system having a primary separation system and a filter downstream of the primary separation system. The filter has an upstream side to receive an airflow exiting the primary separation system, and a downstream side fluidly opposite the upstream side. The system has a vacuum fan, a primary suction path between the filter's downstream side and the vacuum fan, a valve in the primary suction path and configured to selectively position to block the primary suction path and create a closed passage at the filter's downstream side, and a secondary suction path between the filter's upstream side and the vacuum fan. A secondary filtration system is in the secondary suction path to separate dirt from an airflow passing therethrough, to thereby clean dirt from the filter's upstream side. A nozzle may be provided to concentrate the air flow as it enters the secondary suction path.