Abstract: The commencement of a developing period of slip is detected by the fact that a time-differential value v.sub.s of a creep velocity v.sub.s (a relative velocity between a peripheral velocity v.sub.m of a driving wheel and a vehicle velocity v.sub.t) exceeds a predetermined reference .delta..sub.1. The termination of the developing period is detected by the fact that a time-differential value v.sub.m of the peripheral velocity v.sub.m becomes equal to zero. During the developing period, a torque command Tp to a main motor controller is decreased by a re-adhesion control signal Tfa which is formed by the combination of a time-dependent component e.sub.1 and a slip-dependent component e.sub.2. After termination of the developing period, the torque command Tp is decreased with time at an appropriate time constant. According to the present invention, the arithmetic logic operation for control can be much simplified without any deterioration of a adhesion performance of an electric vehicle.

Abstract: In a truck for a railway vehicle having a plurality of wheels-and-axles, an arrangement is provided for permitting each wheel-and-axle an optimal steering operation when the truck runs on a curved track, and to simplify the construction of journal box locator. Each journal box is located and fitted to a truck frame by the journal box locator for locating and fitting the journal box to the truck frame in such a fashion that the orbit of movement of the journal box expands upward with respect to the center axis of the truck, and permits the relative displacement between the journal box and the truck frame by elastic deformation of elastic members.

Abstract: From the peripheral velocity v.sub.M of a driving wheel and vehicle velocity v, the changing rate .DELTA.v.sub.s /.DELTA.t of the relative velocity v.sub.s therebetween with respect to time is obtained. The changing rate .DELTA.f/.DELTA.t of the traction force f produced in the driving wheel at that time is obtained from a detected armature current of a motor driving the driving wheel. A driving torque produced by the motor is so controlled as to be decreased when polarities of the changing rate in the relative velocity and that in the traction force are different from each other.