Vehicle steering system and manufacturing method for vehicle steering system
First Claim
1. A steer-by-wire vehicle steering system that converts rotative power of an electric motor into a movement of a steered shaft in an axial direction via a ball screw mechanism, the vehicle steering system comprising:
- a threaded shaft provided at an intermediate part of the steered shaft;
a ball nut screwed to the threaded shaft via balls and rotatable together with a rotor of the electric motor;
a tubular housing that houses the electric motor and the ball nut and through which the steered shaft is passed; and
first and second stoppers arranged at first and second end portions of the housing, respectively,wherein the steered shaft has first and second contact portions located respectively at first and second end portions of the threaded shaft,radial gaps are formed between outer peripheries of the respective contact portions and an inner periphery of the rotor so that the each of the contact portions is allowed to be inserted into the rotor, andwhen the steered shaft moves in the axial direction, one of an end face of the contact portions, which is on a moving direction side and passed through the rotor, contacts an end face of a corresponding one of the stoppers, so that a travel amount of the steered shaft in the axial direction is restricted.
1 Assignment
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Accused Products
Abstract
Provided is a vehicle steering system that is able to restrict a travel amount of a steered shaft in a housing, that is small and that has an excellent strength. The vehicle steering system is a steer-by-wire vehicle steering system that converts rotative power of electric motors into a movement of a steered shaft in an axial direction via a ball screw mechanism. One of contact portions at respective ends of a screw shaft at an intermediate part of the steered shaft passes through a rotor based on a moving direction of the steered shaft so as to contact a corresponding one of the corresponding stoppers thereby restricting a travel amount of the steered shaft. The stoppers are made of a material different from that of the housing and having a high strength.
10 Citations
9 Claims
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1. A steer-by-wire vehicle steering system that converts rotative power of an electric motor into a movement of a steered shaft in an axial direction via a ball screw mechanism, the vehicle steering system comprising:
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a threaded shaft provided at an intermediate part of the steered shaft; a ball nut screwed to the threaded shaft via balls and rotatable together with a rotor of the electric motor; a tubular housing that houses the electric motor and the ball nut and through which the steered shaft is passed; and first and second stoppers arranged at first and second end portions of the housing, respectively, wherein the steered shaft has first and second contact portions located respectively at first and second end portions of the threaded shaft, radial gaps are formed between outer peripheries of the respective contact portions and an inner periphery of the rotor so that the each of the contact portions is allowed to be inserted into the rotor, and when the steered shaft moves in the axial direction, one of an end face of the contact portions, which is on a moving direction side and passed through the rotor, contacts an end face of a corresponding one of the stoppers, so that a travel amount of the steered shaft in the axial direction is restricted. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A steer-by-wire vehicle steering system that converts rotative power of an electric motor into a movement of a steered shaft in an axial direction via a ball screw mechanism, the vehicle steering system comprising:
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a threaded shaft provided at an intermediate part of the steered shaft; a ball nut screwed to the threaded shaft via balls and rotatable together with a rotor of the electric motor; a tubular housing that houses the electric motor and the ball nut and through which the steered shaft is passed; and first and second stoppers arranged at first and second end portions of the housing, respectively, wherein the steered shaft has first and second contact portions located respectively at first and second end portions of the threaded shaft, radial gaps are formed between outer peripheries of the respective contact portions and an inner periphery of the rotor so that the each of the contact portions is allowed to be inserted into the rotor, and when the steered shaft moves in the axial direction, one of the contact portions, which is on a moving direction side and passed through the rotor, contacts a corresponding one of the stoppers, so that a travel amount of the steered shaft in the axial direction is restricted, wherein; each of the stoppers has an annular shape; and each of the first and second end portions of the housing has an annular fitting surface to which an outer periphery of a corresponding one of the stoppers is fitted, and a receiving portion that receives the corresponding stopper axially.
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Specification