Electric rear wheel steering actuator
First Claim
1. An electrically powered actuator for moving an object along a linear path comprising:
- a generally tubular housing;
an electric motor enclosed in said housing and having a rotatable output shaft, said output shaft having first and second ends;
a first planetary gear set enclosed in said housing and having an input attached to said first end of said output shaft and an output;
a first ball screw assembly enclosed in said housing and having a rotatable nut attached to said first planetary gear set output and a screw driven along a linear path of movement by said nut and adapted to be attached to an object to be moved, said output shaft, said first planetary gear set and said first ball screw assembly sharing a common longitudinal axis with said housing;
a second planetary gear set enclosed in said housing and having an input attached to said second end of said output shaft and an output;
a second ball screw assembly enclosed in said housing and having a rotatable nut attached to said second planetary gear set output and a screw driven along a linear path of movement by said nut and adapted to be attached to an object to be moved, said output shaft, said second planetary gear set and said second ball screw assembly sharing a common longitudinal axis with said housing; and
brake means attached to said output shaft whereby when said electric motor is actuated, said output shaft rotates said planetary gear sets and said nuts to move said screws along said path of movement and when said first ball screw assembly screw reaches a predetermined position along said path, said brake means is actuated to stop the rotation of said output shaft.
1 Assignment
0 Petitions
Accused Products
Abstract
An apparatus for moving an object along a linear path, such as a tie rod end in a vehicle steering system, includes a generally tubular housing, an electric motor having a rotatable output shaft, a planetary gear set having an input attached to the output shaft and an output and a ball screw assembly having a rotatable nut attached to the planetary gear set output and a screw driven along a linear path of movement by the nut and adapted to be attached to an object to be moved, the output shaft, the planetary gear set and the ball screw assembly sharing a common longitudinal axis with the housing. The apparatus also includes a position sensor mounted on the housing for sensing the position of the screw along the path of movement and generating a sensor signal representing the position and a brake means attached to the output shaft whereby when the electric motor is actuated, the output shaft rotates the planetary gear set and the nut to move the screw along the path and when the screw reaches a predetermined position along the path, the brake is actuated to stop the rotation of the output shaft.
42 Citations
8 Claims
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1. An electrically powered actuator for moving an object along a linear path comprising:
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a generally tubular housing; an electric motor enclosed in said housing and having a rotatable output shaft, said output shaft having first and second ends; a first planetary gear set enclosed in said housing and having an input attached to said first end of said output shaft and an output; a first ball screw assembly enclosed in said housing and having a rotatable nut attached to said first planetary gear set output and a screw driven along a linear path of movement by said nut and adapted to be attached to an object to be moved, said output shaft, said first planetary gear set and said first ball screw assembly sharing a common longitudinal axis with said housing; a second planetary gear set enclosed in said housing and having an input attached to said second end of said output shaft and an output; a second ball screw assembly enclosed in said housing and having a rotatable nut attached to said second planetary gear set output and a screw driven along a linear path of movement by said nut and adapted to be attached to an object to be moved, said output shaft, said second planetary gear set and said second ball screw assembly sharing a common longitudinal axis with said housing; and brake means attached to said output shaft whereby when said electric motor is actuated, said output shaft rotates said planetary gear sets and said nuts to move said screws along said path of movement and when said first ball screw assembly screw reaches a predetermined position along said path, said brake means is actuated to stop the rotation of said output shaft. - View Dependent Claims (2, 3)
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4. An electrically powered actuator for moving an object along a linear path comprising:
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a housing; an electric motor enclosed in said housing and having a rotatable output shaft; a planetary gear set enclosed in said housing and having an input attached to said output shaft and an output; a ball screw assembly enclosed in said housing and having a rotatable nut attached to said planetary gear set output and a screw adapted to be attached to an object to be moved; a position sensor mounted on said housing for sensing the position of said screw along a path of movement and generating a sensor signal representing said position, said position sensor including a pair of spaced apart Hall effect transducers mounted on said housing and a pair of spaced apart magnets connected to said shaft, each of said transducers being responsive to at least one of said magnets for generating said sensor signal as an output signal representing movement of said screw in an associated direction of travel along said path of movement; and brake means attached to said output shaft whereby when said electric motor is actuated, said output shaft rotates said planetary gear set and said nut to move said screw along said path of movement and when said screw reaches a predetermined position along said path, said brake means is actuated to stop the rotation of said output shaft. - View Dependent Claims (5, 6)
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7. A steering actuator for a wheeled vehicle comprising:
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a generally tubular housing; an electric motor enclosed in said housing and having a rotatable output shaft; a ball screw assembly enclosed in said housing and having a rotatable nut attached to said electric motor output shaft and a screw adapted to be attached to a tie rod end of a vehicle steering system, said electric motor including a field portion mounted in said housing adjacent said nut and an armature portion mounted on said nut for rotation therewith; a position sensor mounted on said housing for sensing the position of said screw along a path of movement and generating a sensor signal representing said position; and brake means attached to said output shaft whereby when said electric motor is actuated, said electric motor rotates said nut to move said screw along said path of movement and when said screw reached a predetermined position along said path, said brake means is actuated to stop the rotation of said output shaft of said electric motor.
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8. A steering actuator for a wheeled vehicle steering system for moving a tie rod end a predetermined linear distance comprising:
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a generally tubular housing; an electric motor enclosed in said housing and having a rotatable output shaft; a planetary gear set enclosed in said housing and having an input attached to said output shaft and an output; a ball screw assembly enclosed in said housing and having a rotatable nut attached to said planetary gear set output and a screw adapted to be attached to a tie rod end to be moved; a position sensor including a pair of spaced apart Hall effect transducers mounted on said housing and a pair of spaced apart magnets connected to said output shaft and positioned between said transducers, each of said magnets being associated with at least one of said transducers for generating an output signal from said associated transducer representing the position of said screw in at least one direction of movement along a path of movement; and brake means attached to said output shaft whereby when said electric motor is actuated, said output shaft rotates said planetary gear set and said nut to move said screw along said path of movement and when said screw reaches a predetermined position along said path, said brake means is actuated to stop the rotation of said output shaft.
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Specification