Patent ID: 11937412
Assignee: BOMBARDIER TRANSPORTATION GMBH
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An arrangement for cooling power semiconductor devices (2) of a converter (1) arranged in a closed casing (3) with said semiconductor devices in a bottom (4) of the casing on top of a heat sink (5) having members (6), such as fins, for heat exchange extending externally of the casing out from the bottom, the arrangement comprising:
a channel (8) for conducting a flow of air to pass said members (6) for cooling thereof, in which a first portion (7) of said channel has the casing bottom (4) as a ceiling and receiving said members,
a fan (9) located with a suction side connected to said first channel portion (7) to create a flow of air from an inlet (16) from the exterior (19) into said channel while passing the heat sink members (6), and
a filter (18) covering said inlet (16) to the channel for removal of dust and debris from air entering the channel from the exterior,
wherein the channel comprises a second portion (14) connected to the first portion (7) in the direction of the air flow through the channel upstream of the first portion,
the second channel portion (14) extends along a delimiting lateral wall (15) of said casing (3) connecting to said bottom (4) to conduct air downwards along this lateral casing wall to enter the first channel portion (7),
the channel inlet (16) is located in the second channel portion (14) opposite to said lateral casing wall (15) and has a longitudinal extension in the direction of the extension of this channel portion to the region of the start (17) of the first channel portion (7),
the channel inlet (16) is designed to form resistance to flow of air therethrough through the filter (18) and into the second channel portion (14) increasing in the direction towards said first channel portion (7) to in this direction increase the air pressure difference between the exterior and the inner of the second channel portion and by that reduce the air flow into the second channel portion (14),
the channel inlet (16) comprises an air-impermeable channel wall member (21) having the filter (18) internally thereof and provided with through-holes (22) for air to pass, and
the total area of the through-holes (22) in subsequent sections of the second channel portion (14) decreases the closer the section is to the start (17) of the first channel portion (7).