Linear actuator

Patent metadata

Field	Value
Publication number	US-9021903-B2
Application number	US-201113012165-A
Country	US
Kind code	B2
Filing date	Jan 24, 2011
Priority date	Jan 26, 2010
Publication date	May 5, 2015
Grant date	May 5, 2015

Abstract

A linear actuator has a housing, a piston slideable within the housing along a slide axis, a first shaft rotatable about a first axis substantially perpendicular to the slide axis, a second shaft rotatable about a second axis parallel to the slide axis, in which the second shaft and the piston are engaged to convert rotational motion of the second shaft into linear motion of the piston, and in which the first shaft and the second shaft are engaged by a ball-worm gear.

First claim

The invention claimed is:

1. An extensible linear actuator, comprising:
a subassembly of a first shaft rotatable about a first axis and at least one electric motor driving the first shaft,
a housing having an outer wall,
a rod slideable along a slide axis within the housing,
a second shaft in the housing, the second shaft rotatable about a second axis transverse to the first axis,
the second shaft and the rod being engaged via a screw joint to convert rotational motion of the second shaft into linear motion of the rod along the slide axis, wherein the rod is telescopic within the housing so as to change the length of the linear actuator, and
the linear actuator further comprising a ball-worm gear comprising a first mechanical engagement formation on the first shaft, a second mechanical engagement formation on the second shaft, and a plurality of balls engaging the first and second mechanical engagement formations wherein the subassembly is mounted to the outer wall of the housing, and the housing defines an aperture in the outer wall exposing the mechanical engagement formation on the second shaft, and the first mechanical engagement formation engages the second mechanical engagement formation through the aperture via the ball-worm gear.

2. The linear actuator according to claim 1 in which the first axis is substantially perpendicular to the second axis.

3. The linear actuator according to claim 1 in which the second axis and the slide axis are parallel.

4. The linear actuator according to claim 3 in which the second axis and the slide axis are coincident.

5. The linear actuator according to claim 1 in which the screw joint is a ball-screw joint.

6. The linear actuator according to claim 5 in which the second shaft is connected to a shaft of the ball screw joint and the rod is connected to a nut of the ball screw joint.

7. The linear actuator according to claim 6 in which the rod at least partially surrounds the shaft of the ball screw joint.

8. The linear actuator according to claim 1 comprising a first motor and a second motor mounted at a first end and a second end of the first shaft respectively, on either side of the housing.

9. An aircraft actuation subassembly comprising the linear actuator according to claim 1 .

10. An aircraft landing gear assembly comprising the aircraft actuation subassembly according to claim 9 .

11. The linear actuator according to claim 1 , wherein the mechanical engagement formation on the first shaft defines a concave outer profile to receive part of the mechanical engagement formation of the second shaft.

12. The linear actuator according to claim 11 , wherein the concave outer profile has substantially the same radius as the second shaft.

Assignees

• Elliott Nicholas
• Didey Arnaud
• Airbus Operations Ltd

Inventors

• Elliott Nicholas
• Didey Arnaud

Classifications

• F16H25/20

  Screw mechanisms (with automatic reversal F16H25/12) · CPC title

• F16H2025/209

  using worm gears · CPC title

• B64C13/28 Primary

  mechanical · CPC title

• F16H1/163

  with balls between the co-operating parts · CPC title

• Y02T50/44

  Cross-Sectional Technologies · mapped topic