Abstract: In a motor-driven power steering apparatus, in an intermediate assembled state in which an input shaft, an output shaft, a torsion bar, a worm gear, a worm wheel, a torque detecting apparatus and a spiral cable are assembled in a gear housing, and an electric motor is not assembled yet, a rotation preventing arm which prevents the worm gear from rotating is loaded with respect to the gear housing.

Abstract: In a motor-driven power steering apparatus, in an intermediate assembled state in which an input shaft, an output shaft, a torsion bar, a worm gear, a worm wheel, a torque detecting apparatus and a spiral cable are assembled in a gear housing, and an electric motor is not assembled yet, a rotation preventing arm which prevents the worm gear from rotating is loaded with respect to the gear housing.

Abstract: A hydraulic power steering apparatus is provided with a check valve regulating a back flow of a working fluid from a power cylinder mechanism to a hydraulic pump side. A valve element slidably accommodated within a valve body of the check valve has three guide portions protruding to an outer side in a diametrical direction. A valve internal oil path in which the working fluid circulates by a pair of guide portions adjacent in a peripheral direction is formed in the valve element. The guide portion is constituted by a slidable contact portion having a sidable contact surface surface contacted with an inner peripheral surface of the valve body, and a coupling portion coupling a base body portion and the sidable contact portion. A width (W1) in a peripheral direction of the sidable contact surface is larger than a width in the peripheral direction of the coupling portion.

Abstract: A hydraulic power steering apparatus is provided with a check valve regulating a back flow of a working fluid from a power cylinder mechanism to a hydraulic pump side. A valve element slidably accommodated within a valve body of the check valve has three guide portions protruding to an outer side in a diametrical direction. A valve internal oil path in which the working fluid circulates by a pair of guide portions adjacent in a peripheral direction is formed in the valve element. The guide portion is constituted by a slidable contact portion having a slidable contact surface surface contacted with an inner peripheral surface of the valve body, and a coupling portion coupling a base body portion and the sidable contact portion. A width (W1) in a peripheral direction of the sidable contact surface is larger than a width in the peripheral direction of the coupling portion.

Abstract: In a power steering apparatus provided with a damper valve, a second valve apparatus of the damper valve is provided with a valve plate in contact with and apart from a partition member so as to open and close a through flow passage provided in the partition member, and a fluid storing recess portion is provided in a contact area between the partition member and the valve plate.

Abstract: In a power steering apparatus provided with a damper valve, the damper valve holds a partition member between a cap and the housing.

Abstract: A damper valve for a hydraulic power steering device is disposed in a hydraulic oil circuit connecting an oil passage changing-over valve in a gear box and left and right oil chambers of a power cylinder. It is provided with a piston valve which is opened by through-flow of hydraulic oil returned back to the oil passage changing-over valve from either one of the left and right chambers of the power cylinder, and a check valve which is disposed in a valve body of the piston valve and which allows only hydraulic oil supplied from the oil passage changing-over valve to either one of the left and right chambers of the power cylinder to flow through the check valve. The piston valve is structured such that a throttle oil passage is formed by through flow of the returned hydraulic oil having an oil pressure of a predetermined value or less, and a fully opened oil passage is formed by through flow of the returned hydraulic oil having an oil pressure of more than the predetermined value.