Eccentric tool

An adjustment tool is disclosed herein. For example, an adjustment tool is provided comprising an input gear having gear teeth and an output gear having gear teeth, wherein the input gear and the output gear are in meshed engagement, an input shaft centrally coupled to the input gear, wherein the input gear is configured to rotate about the input shaft, and a housing supporting the input shaft for rotation and supporting a fastener, wherein a tooth of the output gear protrudes from the housing.

FIELD

The present disclosure relates to landing gear, and more particularly, to adjustment tools for use in landing gear.

BACKGROUND

Landing gear supports an aircraft while the aircraft is on the ground. Landing gear may comprise a variety of links coupled together at various joints. Relative distances between two points may benefit from adjustment during installation of the landing gear into an aircraft. For example, in dual side stay landing gear, the aft stay length may benefit from adjustment during installation into the aircraft.

SUMMARY

An adjustment tool is disclosed comprising an input gear having gear teeth and an output gear having gear teeth, wherein the input gear and the output gear are in meshed engagement, an input shaft centrally coupled to the input gear, wherein the input gear is configured to rotate about the input shaft, a housing supporting the input shaft for rotation and supporting a fastener, wherein a tooth of the output gear protrudes from the housing.

Further, an apparatus is disclosed comprising, an eccentric bushing having a plurality of circumferentially disposed gear teeth, a secondary bushing disposed within the eccentric bushing, and an aperture disposed within the secondary bushing, an input gear having input gear teeth and an output gear having output gear teeth, wherein the input gear teeth and the output gear teeth are in meshed engagement, wherein the output gear teeth are configured to be placed into meshed engagement with the plurality of circumferentially disposed gear teeth, wherein rotation of the eccentric bushing causes rotation of the secondary bushing, wherein rotation of the secondary bushing causes the aperture to be displaced along a diameter of the eccentric bushing.

DETAILED DESCRIPTION

As used herein, the term “meshed engagement” may refer to the engagement of two or more sets of gear teeth. In that regard, while in meshed engagement, two sets of gear teeth may exert rotational force on one another. Stated another way, while in meshed engagement, a first set of gear teeth may drive a second set of gear teeth to rotate.

With reference toFIG. 1, a portion of a landing gear100is shown. Upper stay108is coupled to lower stay110at pivot joint112. Stay length102is shown representing the distance between aperture104and aperture106when upper stay108is positioned 180 degrees from lower stay110and pivot joint112is fixed to prevent pivoting. Line150passes through aperture104, pivot joint112and aperture106. During installation of the landing gear into the aircraft, it may be desirable to adjust stay length102. In that regard, eccentric bushing assemblies116and114are configured such that rotation of an eccentric bushing of the eccentric bushing assembly displaces aperture104and/or aperture106along a diameter of the eccentric bushing (e.g., along line150). In that regard, the displacement of aperture104and/or aperture106will change stay length102by either increasing or decreasing the distance of stay length102. It is desirable to easily and accurately effect rotation of the eccentric bushing during adjustment, but also to prevent rotation of an eccentric bushing when adjustment is not desired. For example, during typical aircraft operation, it would be desirable to constrain the eccentric bushing from rotation.

With reference toFIG. 2, eccentric bushing assembly114is illustrated. Aperture106is shown within secondary bushing208. Secondary bushing208is shown within eccentric bushing212. Eccentric bushing212may comprise any suitable eccentric bushing. Eccentric bushing212has a non-zero eccentricity. In that regard, the eccentricity may range from infinitesimally above zero to 1. Eccentric bushing212comprises an eccentric annular structure. In that regard, the radial width of eccentric bushing212may vary about the circumference of eccentric bushing212. As shown, for example, radial width220at a first portion of the circumference of eccentric bushing212is larger than radial width222at a second portion of the circumference of eccentric bushing212. Eccentric bushing212may comprise a plurality of circumferentially disposed gear teeth210. Any number of gear teeth is contemplated herein. Eccentric bushing212may comprise any suitable material, for example, titanium, aluminum, steel, stainless steel such as 300 M stainless steel and/or chromium-nickel-tungsten martensitic alloy (also known as Greek Ascoloy).

Secondary bushing208may comprise an annular structure. In that regard, secondary bushing208may have a circular profile, for example, taking a cylindrical geometry. Secondary bushing208may comprise any suitable material, for example, titanium, aluminum, steel, stainless steel such as 300 M stainless steel and/or chromium-nickel-tungsten martensitic alloy (also known as Greek Ascoloy). Secondary bushing208may be mounted or otherwise disposed within eccentric bushing212. In that regard, rotation of eccentric bushing212will effect rotation of secondary bushing208. Due to the eccentricity of eccentric bushing212, rotation of eccentric bushing212will displace aperture106along a diameter of eccentric bushing212.

Support ring224may comprise a structure having aperture106. Support ring224may be disposed within secondary bushing208and may be configured to rotate with secondary bushing208.

Locking key202may be mounted on joint housing lugs226and secured thereto with bolts or other fasteners through apertures214and216. Locking key202has a plurality of gear teeth206. Plurality of gear teeth206of locking key202is shown in meshed engagement with plurality of circumferentially disposed gear teeth210of eccentric bushing212. In that regard, locking key202constrains plurality of circumferentially disposed gear teeth210of eccentric bushing212from rotation. Locking key202may comprise any suitable material, for example, titanium, aluminum, steel, stainless steel such as 300 M stainless steel and/or chromium-nickel-tungsten martensitic alloy (also known as Greek Ascoloy).

With reference toFIG. 3A, when adjustment of stay length102is desired, adjustment tool300may be used to drive rotation of eccentric bushing212. Adjustment tool300comprises input shaft306, output shaft310, input gear302, housing312, and output gear304.

Input shaft306may comprise head314. Head314may be configured to engage with any suitable wrench or tool to drive rotation of input shaft306. In various embodiments, and as shown, head314is hexagonal. In various embodiments, head314may comprise a slotted screw head, a Philips screw head, a star shaped screw head such as available under the TORX trademark, a square head, or any other suitable geometry to couple to a tool to drive rotation of input shaft306.

Input shaft306supports input gear302for rotation. Input shaft306thus comprises an axis of rotation of input gear302. Input gear302comprises plurality of gear teeth316.

Output shaft310supports output gear304for rotation. Output shaft310thus comprises an axis of rotation of output gear304. Output gear304comprises plurality of gear teeth318.

Housing312comprises generally parallel plates that support input shaft306and output shaft310. Housing312also comprises aperture320. Aperture320may accept a bolt308for securing housing312to joint housing lugs226. It is contemplated that any suitable fastener may be used with aperture320to secure housing312to joint housing lugs226. Output gear304and/or plurality of gear teeth318of output gear304may protrude from housing312, for example, as in protrusion322. Protrusion322may allow plurality of gear teeth318of output gear304to be disposed in meshed engagement with eccentric bushing212.

With reference toFIG. 3B, a portion of housing312is shown transparently for clarity. Plurality of gear teeth318of output gear304is shown in meshed engagement350with plurality of gear teeth316of input gear302. In that regard, input shaft306may rotate input gear302in direction352. Through meshed engagement350, input gear302may drive rotation of output gear304in direction354. Of course, rotation of input shaft306in a direction opposite direction352would cause output gear304to rotate in a direction opposite direction354. In that regard, output gear304may be rotated clockwise or counter-clockwise in response to rotation of input gear302, though output gear304and input gear302will rotate in opposite directions. The ratio of the number of gear teeth in plurality of gear teeth316of input gear302to the number of gear teeth in plurality of gear teeth318of output gear304(which may be referred to as a gear ratio) may be any suitable ratio. For example, in various embodiments, the gear ratio input gear302to output gear304is between 1.2:1 to 2:1

With reference toFIG. 4, cross sectional view400illustrates adjustment tool300interacting with eccentric bushing assembly114. In operation, rotation of input shaft306may drive input gear302to rotate in a first direction. Housing312may be coupled to joint housing lugs226via a fastener disposed through aperture320.

Through meshed engagement350, input gear302will drive rotation of output gear304. Output gear304is in meshed engagement with eccentric bushing212. The rotation of output gear304will thus drive rotation of eccentric bushing212and secondary bushing208. In that regard, aperture106will be displaced along a diameter of eccentric bushing212, here shown as displacement402. In that regard, rotation of input gear302in a first direction will effect displacement of aperture106in a first direction and rotation of input gear302in a second direction will effect displacement of aperture106in a second direction. Displacement402may be along line150. Thus, stay length102may be increased or decreased by displacement along line150.

With reference toFIG. 5, an exterior view500is shown of adjustment tool300. Bolt308passes through aperture506of joint housing lugs226and aperture320of securing adjustment tool300to secure adjustment tool300to joint housing lugs226. Nut502is used to secure bolt308.

After adjustment, locking key202may be take the place of adjustment tool300, such as the in the configuration shown inFIG. 2. Locking key202may thus constrain the eccentric bushing212from rotation until adjustment is desired.