Abstract: A method of manufacturing a bearing device for a wheel, the method including forming an inner shaft so that an outside diameter of the inner shaft at a first portion is smaller than an outside diameter of the inner shaft at a second portion which is adjacent to the first portion, the peripheral surface of the inner shaft at the first portion is to be heat-treated, and the peripheral surface of the inner shaft at the second portion is not to be heat-treated, and the first portion has a predetermined length in an axial direction, and heat-treating the peripheral surface of the inner shaft at the first portion, and finishing a peripheral surface of the inner shaft by lathe turning whereby a step is not formed at a border between the first portion and the second portion.

Abstract: A cage includes a radially inward-side annular plate, a radially outward-side annular wall, a plurality of pillar portions, and pockets formed in the pillar portions. Rollers are rotatably retained in the pockets. An inner peripheral surface of the radially outward-side annular wall is formed so as to be oblique toward a radially outward direction. A radially outward-side end surface of each of the rollers has a spherical surface shape.

Abstract: An angle computing section determines an angle of a rotor, and an angular velocity computing section determines angular velocity of the rotor. A command current computing section determines, from a steering torque and vehicle velocity, command currents and taken along d-q axes. An open loop control section determines, from command currents and angular velocity, command voltages taken along the d-q axes in accordance with motor circuit equations. A d-q axis/three-phase conversion section converts the command voltages into command voltages of three phases. A ? computing section determines the number of armature winding flux linkages included in a motor circuit equation from a q-axis command voltage, the current value detected by a current sensor, and the angular velocity. Circuit resistance including armature winding resistance R included in the motor circuit equation may also be determined by means of the same configuration.