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US 5,099,161 AGranted
Compact electric linear actuator with tubular rotor
AssigneeSavair Inc.
InventorMichael H. Wolfbauer, III
Life of this patent
Estimating the term…
Abstract
A compact electrically driven linear actuator having an electric motor in a housing. The electric motor has a cylindrically-shaped rotor assembly which is attached to and circumscribes a threaded spindle. A portion of the threaded spindle is received in an axial bore of a non-rotatable extendable arm. A nut attached to one end of the non-rotatable extendable arm is threadably received on the threaded spindle. Rotation of the threaded spindle by the electric motor linearly displaces the nut and the non-rotatable extendable arm along the length of the threaded spindle. In the preferred embodiment, the threaded spindle has a helical ball groove and the nut is a mating ball nut.
Claims19
A compact linear actuator comprising:
- a housing having two opposing end plates, one of said two opposing end plates having an axially disposed aperture provided therethrough;
- a non-rotatable extendable arm slidably extending into said housing through said aperture, said non-rotatable extendable arm having an internal end disposed within said housing, an external end, and a non-threaded axial bore extending from said internal end towards said external end, said non-threaded axial bore extending along a substantial portion of the length of said non-rotatable extendable arm;
- a threaded nut attached to said internal end of said non-rotatable extendable, arm said threaded nut having a helical thread concentric with said non-threaded axial bore;
- an axially disposed threaded spindle rotatably supported within said housing and mounted to said helical thread of said threaded nut, said threaded spindle further extending into said non-threaded axial bore of said non-rotatable extendable arm;
- and
- a bi-directional electrical motor disposed in said housing, said bi-directional electrical motor having a rotor assembly circumscribing and directly connected to said non-rotatable extendable arm, one end of said rotor assembly being directly connected to said threaded spindle to rotate said threaded spindle therewith upon energization of said electrical motor, the rotation of said threaded spindle linearly displacing said threaded nut and said non-rotatable extendable arm relative to said housing.
3 more elements
A linear actuator comprising:
- a housing having a central axis, said housing being enclosed by a pair of end plates attached to opposing ends thereof, one end plate of said pair of end plates having a non-circular aperture provided therethrough;
- a bi-directional motor disposed in said housing, said bi-directional motor having a stator assembly and a rotor assembly substantially concentric with said central axis of said housing;
- a ball screw spindle extending through said rotor assembly, said ball screw spindle having one end attached directly to said rotor assembly and rotatable therewith about said central axis;
- an extendable arm slidably mounted in said housing through said non-circular aperture of said one end plate, said extendable arm having a cross section corresponding to the shape of said non-circular aperture to prevent the rotation of said extendable arm relative to said one end plate, said extendable arm further having a non-threaded axial bore substantially concentric with said central axis, said non-threaded axial bore extending from an internal end of said extendable arm towards an external end, said ball screw spindle being axially and non-rotatably translatable in said non-threaded axial bore of said extendable arm;
- and
- a ball nut attached adjacent to said internal end of said extendable arm, said ball nut threadably received on said ball screw spindle and linearly displaceable along said ball screw spindle in response to the rotation of said ball screw spindle by said bi-directional motor.
3 more elements
A linear actuator comprising:
- an arm guide having an actuator sleeve portion and a radial flange portion provided at one end of said actuator sleeve portion, said actuator sleeve portion having a longitudinally extending internal guideway passing therethrough, said longitudinally extending internal guideway having non-circular side walls;
- a bi-directional electric motor having a stator assembly and a cylindrically-shaped rotor assembly circumscribing said actuator sleeve portion of said arm guide;
- a housing member enclosing said bi-directional electric motor, said housing member having one end attached to said radial flange portion and an opposite end;
- an end plate attached to said opposite end of said housing member, said end plate having an axially disposed aperture provided therethrough generally aligned with said one end of said arm guide;
- an extendable arm slidably disposed in said longitudinally extending internal guideway of said arm guide, said extendable arm having non-circular sides mating with said non-circular side walls of said longitudinally extending internal guideway to prevent said extendable arm from rotating relative to said arm guide, said extendable arm further having segment portions of a helical ball groove provided thereon;
- a ball nut mounted on said segment portions of said helical ball groove at the end of said actuator sleeve portion opposite said radial flange portion, said ball nut being attached to said radial flange portion of said cylindrically-shaped rotor assembly through said axially disposed aperture provided in said end plate;
- and
- means for restraining the axial displacement of said cylindrically-shaped rotor assembly relative to said stator assembly and the axial displacement of said ball nut relative to the end of said actuator sleeve portion.
5 more elements
Dependencies are inferred from the claim text.