Abstract: The present invention provides an electric compressor in which the centering operation between a container and a main bearing member can be carried out precisely, and the compressor can easily be assembled. A main bearing member is provided at its peripheral edge with an inserting portion and an abutting portion, an outer diameter of the inserting portion is set smaller than that of the abutting portion. The outer diameter of the inserting portion is set slightly smaller than an inner diameter of an opening end of the container. With this structure, a centering operation can be carried out precisely and easily, and the reliability and performance of the compressor are enhanced, and costs thereof can be reduced.

Abstract: A drive transmission apparatus includes a first coupling portion having a polygonal shape; a second coupling portion having a hole portion which has a cross-sectional configuration larger than the first coupling portion, the hole portion being engageable with the first coupling portion; and a center shaft provided on the first coupling or the second coupling, the center shaft penetrating the other one of the first and second coupling.

Abstract: A drive transmission apparatus includes a first coupling portion having a polygonal shape; a second coupling portion having a hole portion which has a cross-sectional configuration larger than the first coupling portion, the hole portion being engageable with the first coupling portion; and a center shaft provided on the first coupling or the second coupling, the center shaft penetrating the other one of the first and second coupling.

Abstract: A refrigerant go-around passage is provided in a housing of a compressor. The passage takes in refrigerant discharged from a compression mechanism into the housing, makes the refrigerant go around an axial line of the compressor and finally returns the refrigerant to the discharge-port side of the housing while separating liquid contained in the refrigerant from the refrigerant by centrifugation or by centrifugation and collision. In the mid portion of the refrigerant go-around passage, a liquid returning port is provided for returning the separated liquid to the housing in such a manner that the liquid returning port has an orientation that has a component in a direction of gravity and that is deviated from a traveling direction of the refrigerant.

Abstract: In an electric compressor, an inverter case of an inverter is externally attached to an end wall of a housing in an axial direction on the side of a suction port to a compression mechanism. An intake passage for leading fluid returned from the outside into the suction port is provided in the inverter case. The intake passage has a thermal binding portion for thermally binding the intake passage to the inverter. According to the above structure, an exclusive part in the housing is eliminated even though the inverter is installed in the electric compressor, and the inverter is cooled efficiently.

Abstract: Lubricating liquid fed from a reservoir to a compression mechanism is collected by a circumferential wall that surrounds the drive shaft of the compression mechanism and rotates synchronously with it immediately after liquid is discharged into the space inside the housing with or without compressed fluid. Liquid is then urged outward under centrifugal force from an outlet formed at a preset axial location of the circumferential wall. Exiting liquid is received by a fixed liquid return cover that surrounds the circumferential wall near its outlet and led back to the reservoir.

Abstract: A drive transmission apparatus includes a first coupling portion having a polygonal shape; a second coupling portion having a hole portion which has a cross-sectional configuration larger than the first coupling portion, the hole portion being engageable with the first coupling portion; and a center shaft provided on the first coupling or the second coupling, the center shaft penetrating the other one of the first and second coupling.

Abstract: In a method for controlling a rear wheel steering device of a front and rear wheel steering vehicle, the target computed rear wheel steering angle is defined as a value smaller than the normal computed target rear wheel steering angle when the load of the steering actuator is greater than a prescribed threshold value, and which is otherwise equal to the normal computed target rear wheel steering angle, and the steering actuator is actuated according to a deviation of the actual rear wheel steering angle from the modified computed target rear wheel steering angle, typically with a duty ratio control. Thus, the rear wheel steering device can be operated in a satisfactory manner even when the output capacity of the actuator for the rear wheel steering device is limited, and the steering load is high. A high load condition typically occurs when the vehicle is stationary and when the steering wheel is turned sharply while the vehicle is traveling over a road surface having a high frictional coefficient.

Abstract: The road friction is determined from the deviation of the estimated yaw rate under a standard condition from the actually measured yaw rate. The system for determining the road friction includes a parameter identification unit which determines a parameter of a variation term defined in the transfer function of the model for the vehicle response. The variation term may consist of a zero-th order or a first-order transfer function which would not cause any large computation load, and may not depend on the vehicle speed. The determined road friction may be used for controlling the rear wheel steering angle of a four wheel steering vehicle.

Abstract: An actuator for effecting a steering action is controlled by a feed-forward variable based on a target steering angle, a state feedback control variable based on an actual steering angle, and an integral control variable given as a sum of an integrated value of a deviation between the target steering angle and the actual steering angle, and an integrated value cancelling variable based on the target steering angle. The integral control variable is disregarded when the detected load is greater than the threshold value. Typically, the integrated value cancelling variable consists of a feedback state variable based on the actual steering angle. Thus, by disregarding the integral control variable in a low speed condition that involves a high load condition but does not require a high tracking capability, the need for the output capacity of the actuator can be substantially reduced without creating substantially any ill effect.

Abstract: An electric motor control system has a motor driver comprising a bridge of switching elements, a pair of failure detectors, and a microcomputer. The motor driver is connected between a battery and an electric motor that is connected between the switching elements. The switching elements are turned on and off according to drive pulse signals supplied from the microcomputer for supplying a pulsed current to the electric motor. The failure detectors monitor the electric energy supplied to the electric motor to detect a period of time in which the supplied electric energy is free of pulses, and supply a signal indicative of the detected period of time to the microcomputer. Based on the signal from the failure detectors, the microcomputer detects a failure when the detected period of time exceeds a predetermined period of time.

Abstract: A four-wheel steering system on an automobile has front road wheels steerable by a steering wheel and rear road wheels steerable by an electric motor and normally biased to a neutral steering position by a spring. The electric motor is energized by a motor driver to steer the rear road wheels through an angle depending on running conditions of the automobile. The electric motor has a winding and two sets of brushes or connecting terminals connected to opposite terminals of the winding. One of the two sets of connecting terminals is connected to the motor driver. The other of the two sets of connecting terminals is connected to a short-circuiting circuit parallel to the motor driver. In the event of a failure, a controller controls the short-circuiting circuit to short-circuit the winding of the motor through the other set of connecting terminals. The short-circuiting circuit comprises a plurality of relays having respective contacts connected in series between the connecting terminals of the other set.