| 摘要 |
PROBLEM TO BE SOLVED: To obtain an electric power steering device which prevents a liquid from intruding thereinto through an attachment part mating surface and causing the deterioration of the electrical insulation properties of electrical components therein.SOLUTION: An electric power steering device 1 according to the invention includes: a gear box having a gear housing 3; and a driving control part 4 which is coaxially connected with the gear box through an attachment mating surface 7 that is an end surface and controls the driving of a motor part 5 that is a source of a steering assist force. An outer diameter gradual increase surface 11, which is connected with the gear box with its outer diameter on the attachment mating surface 7 matched with an outer diameter of the gear box and gradually expands along an axis line direction, is formed at one end part of the driving control part 4. |
