Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H19/00—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion
  • F16H19/02—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion for interconverting rotary or oscillating motion and reciprocating motion
  • F16H19/04—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion for interconverting rotary or oscillating motion and reciprocating motion comprising a rack
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B64—AIRCRAFT; AVIATION; COSMONAUTICS
  • B64C—AEROPLANES; HELICOPTERS
  • B64C25/00—Alighting gear
  • B64C25/32—Alighting gear characterised by elements which contact the ground or similar surface 
  • B64C25/50—Steerable undercarriages; Shimmy-damping
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J1/00—Pistons; Trunk pistons; Plungers
  • F16J1/005—Pistons; Trunk pistons; Plungers obtained by assembling several pieces
  • F16J1/006—Pistons; Trunk pistons; Plungers obtained by assembling several pieces of different materials
  • F16J1/008—Pistons; Trunk pistons; Plungers obtained by assembling several pieces of different materials with sealing lips
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J1/00—Pistons; Trunk pistons; Plungers
  • F16J1/10—Connection to driving members
  • F16J1/14—Connection to driving members with connecting-rods, i.e. pivotal connections
  • F16J1/16—Connection to driving members with connecting-rods, i.e. pivotal connections with gudgeon-pin; Gudgeon-pins
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J7/00—Piston-rods
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T74/00—Machine element or mechanism
  • Y10T74/18—Mechanical movements
  • Y10T74/18056—Rotary to or from reciprocating or oscillating
  • Y10T74/18088—Rack and pinion type
  • Y10T74/18096—Shifting rack

Definitions

• the invention relates to an orientation actuator piston for an aircraft landing gear.
• landing gear comprising a steerable lower part.
• This lower part generally comprises a rod slidably mounted in a box 1 landing gear against a suspension force, the rod carrying at its lower end an axle which receives one or more wheels.
• Some of these undercarriages bear a collar or a sleeve rotatably mounted on the box of the undercarriage being connected to the bottom portion which can be steered by a compass.
• the collar or the sleeve is provided with a ring gear which cooperates with the rack of an orientation actuator to control a pivoting of the orientable lower part.
• mention may be made of the auxiliary undercarriage of the AIRBUS A320 which is provided with such a rack-and-pinion actuation.
• the rack is coupled at both ends to pistons which are mounted sliding sealing in cylinders extending on either side of the landing gear to define two chambers of a hydraulic actuator.
• pistons are made entirely of bronze, for reasons of simplicity. However, such an embodiment proves to be cumbersome. In addition, if in production the outer diameter of the piston is not in accordance with specifications, it is the entire piston that is discarded. Similarly, if in use, the piston wears to the point of no longer enter the size specifications, the entire piston must be discarded to be replaced by a new piston.
• the object of the invention is to provide a piston for a lighter rack steering actuator.
• a rack-and-pinion actuator piston for aircraft landing gear having a light-alloy body having an externally threaded running portion terminated on one side by a shoulder and extended on the other side by a skirt, the body receiving a screw threaded bronze bushing having on its outer wall at least one groove for receiving a seal, the sleeve extending between the shoulder and a pin that passes through the skirt to secure the piston to the rack.
• Bronze means any type of alloy containing mainly copper and tin. Preferably, however, we will retain the alloy defined by the AMS4690 standard.
• light alloy any type of alloy containing mainly aluminum, including light alloys commonly used in aeronautics, such as 2024, or Zinc alloys of the 7000 series.
• Figure 1 is a partial sectional view of a landing gear leg provided with a rack orientation actuator equipped with pistons 1 according to the invention
• FIG. 1 is an enlarged sectional view of the piston of Figure 1.
• the invention applies to the control of orientation of a landing gear 1, of which we can see the caisson 2 in section.
• a rod 3 having at its lower end an axle for carrying one or more wheels is slidably mounted inside the casing 2.
• the rod is connected by a compass (not visible here) to a sleeve 4 which extends here inside the box 2, around the rod 3.
• the sleeve 4 comprises a ring gear 5 which cooperates with a rack 6.
• the displacement of the rack 6 in one direction or the other causes the rotation of the sleeve 4, which causes the rotation of the rod 3, which thus causes the orientation of the wheel or wheels carried by the rod 3, the assembly constituting an orientable portion of the landing gear.
• the ends of the rack 6 are each coupled to a piston 7 which is slidably mounted in a cylinder 8 to define a hydraulic chamber 9.
• a hydraulic port 10 can be injected into the chamber 9 or recover in from this chamber a flow of hydraulic fluid.
• FIG. 1 only one of the cylinders 8 carried by the casing 2 can be seen. It is obvious that the casing 2 carries another identical cylinder, to receive another peg 7 which is coupled to the other end of the rack. .
• the two hydraulic chambers 9 thus formed define a double hydraulic actuator effect to move the rack in one direction or the other.
• the piston 7 comprises a body 10 of light alloy having a cylindrical and externally threaded portion 11.
• the current portion 11 is terminated on one side by a shoulder 12 and on the other side by a skirt 13 which extends the current portion 11.
• a bronze bushing 14 is screwed onto the current portion 11.
• the outer diameter of the bronze bushing 14 is adjusted with a slight clearance to the inside diameter of the cylinder 8.
• the bronze bush 14 has a groove 16 to receive a seal Sealing 17 which seals the chamber 9.
• the bronze bushing 14 is stopped axially between the shoulder 12 and a pin 15 engaged in a transverse bore of the skirt and which passes through the skirt 13 for coupling one of the ends. from the rack 6 to the piston 7.
• the end 20 of the rack 6 is configured as a half-sphere which bears on a shoe 21 conform, which is itself supported on a bottom 18 of the body 10 via a bearing 19.
• a seal 22 is housed in a groove made in the raised face of the shoulder 12 to bear against the bronze bushing 14, to prevent any passage of fluid through the thread of the current part 11.
• the piston thus produced is much lighter than a piston entirely made of bronze.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Aviation & Aerospace Engineering (AREA)
• Pistons, Piston Rings, And Cylinders (AREA)
• Actuator (AREA)
• Transmission Devices (AREA)
• Vehicle Body Suspensions (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (7)

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Citations (5)

Family Cites Families (9)

• 2012
  • 2012-02-08 FR FR1251190A patent/FR2986597B1/fr active Active
• 2013
  • 2013-02-06 CA CA2863762A patent/CA2863762C/fr active Active
  • 2013-02-06 EP EP13703054.0A patent/EP2812244B1/fr active Active
  • 2013-02-06 US US14/377,038 patent/US9574645B2/en active Active
  • 2013-02-06 WO PCT/EP2013/052357 patent/WO2013117607A1/fr not_active Ceased
  • 2013-02-06 BR BR112014019616A patent/BR112014019616A8/pt not_active IP Right Cessation
  • 2013-02-06 CN CN201380008407.2A patent/CN104105639B/zh active Active

Patent Citations (5)

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