Patent ID: 7948138
Filing Date: 2011-05-24
Classification: H02K

Abstract:
1. A rotor comprising: a rotor core fixed to a rotary shaft and having an axially extending hole; a magnet inserted into said hole; and a filling portion arranged in a space between said rotor core and said magnet, wherein on an axial cross section of said rotor core, the space is formed between said rotor core and a radially outer side surface of said magnet in a widthwise central portion of said magnet, and said space in a widthwise end portion of said magnet has a portion wider than said space in the widthwise central portion of said magnet with increased width on the radially outer side, wherein the axially extending hole has two direction defining portions formed at two widthwise radially inner end corners of the hole to uniquely define a direction for the magnet to be inserted into the hole, wherein a pair of said magnets are arranged such that an opposing distance between radially outer side surfaces of said magnets increases as the position moves radially outward in said rotor core, such that said pair of said magnets forms a substantially V-shaped arrangement, wherein said portion wider than said space in the widthwise central portion of said magnet is formed in a valley of said V-shaped arrangement of said pair of said magnets, the rotor further comprising a flux barrier, which is a portion of the space between the rotor core and the magnet, the flux barrier being formed and opposed to the widthwise end surface of the magnet and suppressing rounding of the magnetic flux from the radially outer side surface of the magnet toward the radially inner side surface of the magnet, and wherein the side surface of a hole defining the outer periphery of the flux barrier is continuously connected to an escaping portion in which the side surface of said axially extending hole is largely spaced from the radially outer side surface of said magnet to form a rounded portion relieving the stress concentration in the rotor core.