Blower unit

A blower unit having a housing (2), an impeller (1) accommodated in an impeller chamber (3) in the housing (2), and a motor (12) having a substantially cylindrical body, connected to the impeller (1) via a shaft (15), wherein said motor (12) is disposed in a motor chamber (13) in the housing (2), characterized in that the motor (12) is fixed between walls (14, 18) of the motor chamber (13) by means of one or more buffers, wherein the one or more buffers comprise two sealing rings (16, 17), said two sealing rings (16,17) disposed between respective end faces (20, 19) of the cylindrical body of said motor (12) and, respectively, said walls (14, 18) of the motor chamber (13), and wherein the two sealing rings (16, 17) separate the motor (12) and the shaft (15) from an annular passage for cooling air (33), said annular passage for cooling air (33) formed between an outer circumferential surface (22) of the motor (12) and a wall (23) of a motor housing bottom part (11), wherein said annular passage for cooling air (33) extends annularly substantially completely around said outer circumferential surface (22) of the motor (12), wherein said one or more buffers are configured for preventing cooling air from the annular passage for cooling air (33) from entering an interior region of said motor (12), wherein the annular passage for cooling air (33) extending annularly substantially completely around said outer circumferential surface (22) of the motor (12) is interrupted at only one point by a dividing wall (43) extending in a radial direction from said wall (23) of the motor housing bottom part (11) to said outer circumferential surface (22) of the motor (12), and wherein an air inlet (42) and an air outlet (44) from the annular passage for cooling air (33) are arranged adjacent the dividing wall (43) on different sides thereof and configured for providing cooling air from said annular passage for cooling air (33) around an exterior region of said motor (12), and wherein the annular passage for cooling air (33) is bounded by the two sealing rings (16, 17), by the outer circumferential surface (22) of the motor which extends between the two sealing rings (16, 17), and by the wall (23) of the motor housing bottom part (11) of the housing (2) which extends between the two sealing rings (16, 17).