초록 ▼

An electrically actuated hydraulic power cylinder for use in a vehicle braking system. The power cylinder includes an electric motor, a rotary-to-linear actuator for converting rotary motion of the electric motor to a linear motion, and a hydraulic cylinder. In a preferred embodiment, the rotary-to-

An electrically actuated hydraulic power cylinder for use in a vehicle braking system. The power cylinder includes an electric motor, a rotary-to-linear actuator for converting rotary motion of the electric motor to a linear motion, and a hydraulic cylinder. In a preferred embodiment, the rotary-to-linear actuator is a roller screw assembly. The roller screw assembly converts rotational motion generated by the motor into axial movement of a piston which is disposed within the hydraulic cylinder. The movement of the piston pressurizes a volume of fluid. The pressurized fluid flows through an outlet port connected to either a single wheel brake cylinder or a plurality of wheel brake cylinders, thereby actuating the associated wheel cylinder. In a specific embodiment of the invention, the roller screw assembly is incorporated into the internal structure of the motor for compactness and weight reduction. Also, the hydraulic cylinder may be integrated into a wheel brake assembly for compactness and weight reduction.

대표청구항 ▼

[ What is claimed is:] [1.]1. A power cylinder, comprising:a motor;a roller screw assembly including:an outer screw which rotates about an axis and is operatively connected to said motor, said outer screw having an internal threaded portion;a shaft oriented along said axis, said shaft having an oute

[ What is claimed is:] [1.]1. A power cylinder, comprising:a motor;a roller screw assembly including:an outer screw which rotates about an axis and is operatively connected to said motor, said outer screw having an internal threaded portion;a shaft oriented along said axis, said shaft having an outer threaded portion; anda plurality of rollers threadably engaging said threaded portion of said shaft and said internal threaded portion of said outer screw, wherein said roller screw assembly converts rotary motion of said outer screw into axial motion of said threaded shaft in a direction along said axis; anda hydraulic cylinder including a housing having a bore therein and oriented along said axis, said hydraulic cylinder further including a piston disposed within said bore and operatively connected to said shaft of said roller screw assembly, said bore and said piston defining a fluid chamber, wherein axial motion of said shaft moves said piston within said bore causing expansion or contraction of said fluid chamber depending on the direction of movement of said piston.