CN112572781A

CN112572781A - Front wheel turning speed reduction output mechanism

Info

Publication number: CN112572781A
Application number: CN202011397443.0A
Authority: CN
Inventors: 雷驰; 刘远平; 谷云峰; 张恒; 黄方略; 许杰
Original assignee: AVIC Chengdu Aircraft Design and Research Institute
Current assignee: AVIC Chengdu Aircraft Design and Research Institute
Priority date: 2020-12-04
Filing date: 2020-12-04
Publication date: 2021-03-30
Anticipated expiration: 2040-12-04
Also published as: CN112572781B

Abstract

The invention discloses a nose wheel steering deceleration output mechanism, wherein an input gear (3) sleeved on an undercarriage strut outer cylinder (1) is provided with a straight gear and a bevel gear, the straight gear is meshed with an output gear (4) of a nose wheel steering actuator (2), planetary bevel gears (5) are arranged on a rotary drum (6) and are uniformly distributed along the circumference of the undercarriage strut outer cylinder (1), the rotary drum (6) is sleeved on the undercarriage strut outer cylinder (1) and is hinged with a torsion arm (8) to output deflection torque of the nose wheel to a front tire, a lower bevel gear (7) is sleeved with the undercarriage strut outer cylinder (1) and is fixed with the undercarriage strut outer cylinder (1) along the circumference, and the planetary bevel gears (5) are respectively meshed with the lower bevel gear (7) and the bevel gear on the input gear (3). According to the invention, the front wheel steering speed reducing mechanism is integrated on the landing gear strut of the airplane, so that the output torque is amplified, and the output load requirement of the front wheel steering actuator is reduced. And meanwhile, a plurality of planet gears are adopted to bear load, so that load distribution is optimized.

Description

Front wheel turning speed reduction output mechanism

Technical Field

The invention belongs to the technical field of design of an aircraft landing gear, and particularly relates to a front wheel turning and speed reducing output mechanism.

Background

The moment required by the turning operation of the front wheel of the airplane is usually large, the gear size is usually large when the gear is adopted as a front wheel turning moment output component, only 2-3 teeth of a single pair of gears are usually meshed, the load transfer efficiency is low, and the gear size is further increased. Therefore, the weight of the airplane front wheel steering actuator and the speed reducing mechanism is large at present, and the service life of the speed reducing mechanism is short.

Disclosure of Invention

In view of the above problems of the prior art, it is an object of the present invention to provide a front wheel turning deceleration output mechanism that significantly reduces the weight of a front wheel turning actuator and a deceleration mechanism and improves the mechanism life.

The above object of the present invention is achieved by the following technical solutions:

a front wheel turning speed-reducing output mechanism is composed of a front wheel turning actuator, a rotary drum with two rings of gears on its input gear, two bevel gears on its output gear, a torque arm for outputting the deflection torque of front wheel to front tyre, a lower bevel gear on its outer cylinder and fixed to it, and a planetary bevel gear engaged with the bevel gears on lower bevel gear and input gear.

According to the invention, the nose wheel steering speed reducing mechanism is integrated on the landing gear strut of the airplane to form the speed reducing mechanism integrated with the landing gear strut, so that the output torque amplification is realized, and the output load requirement of the nose wheel steering actuator is reduced. Meanwhile, a plurality of planetary gears are adopted to bear load, and load distribution is optimized, so that the weights of a front wheel steering actuator and a speed reducing mechanism can be obviously reduced, and the service life of the mechanism is prolonged.

Drawings

FIG. 1 is a schematic structural view of a front wheel turning deceleration output mechanism of the invention;

FIG. 2 is a cross-sectional view of the front wheel turning deceleration output mechanism of the present invention;

fig. 3 is an operation principle diagram of the front wheel turning deceleration output mechanism of the invention.

Detailed Description

The invention is described in further detail below with reference to specific embodiments with reference to the attached drawings.

Fig. 1 schematically shows the structure of a front wheel turning deceleration output mechanism of the invention, and fig. 2 is a sectional view of the structure. As shown in the figure, the whole mechanism is arranged on the strut outer cylinder 1. Specifically, an input gear 3 is sleeved on the landing gear strut outer cylinder 1, the input gear 3 is provided with two circles of gears which respectively form a straight gear and a bevel gear, wherein the straight gear is meshed with an output gear 4 of the front wheel bending actuator 2, and the bevel gear is meshed with a planetary bevel gear 5. The planetary bevel gears 5 are arranged on the rotating drum 6 and are uniformly distributed along the circumference of the landing gear strut outer cylinder 1. The rotating cylinder 6 is an undercarriage strut rotating cylinder 6, is also used as a planet carrier, is sleeved on the undercarriage strut outer cylinder 1 to form a revolute pair, and is hinged with a torsion arm 8, and the torsion arm 8 outputs the deflection torque of the front wheel to a front tire. The rotary drum 6 is provided with a plurality of mounting joints along the circumference of the landing gear strut outer cylinder 1 for mounting a plurality of planet gears 5, and the number of the planet gears 5 is generally 2-4, in this example 3, but is not limited to this, and may be more. The lower part of the front wheel steering deceleration output mechanism is provided with a lower bevel gear 7, the lower bevel gear 7 is sleeved with the landing gear support outer cylinder 1 and is fixed with the landing gear support outer cylinder 1 along the circumferential direction by a key groove, and the planetary bevel gears 5 are respectively meshed with the lower bevel gear 7 and the bevel gears on the input gear 3 to form a planetary gear structure.

Fig. 3 is an operation principle diagram of the front wheel turning deceleration output mechanism of the invention. As shown in the figure, the front wheel steering actuator 2 outputs the front wheel steering torque to the output gear 4, the output gear 4 transmits the torque to the input gear 3 through gear engagement, and the first speed reduction is realized, at this time, a speed reduction ratio Z1 is formed, the size of the speed reduction ratio Z1 is related to the gear ratio of the spur gear of the input gear 3 and the output gear 4, and in this case, Z1 is equal to 3. The input gear 3 rotates under the action of torque, so that the lower bevel gear drives the planetary bevel gear 5 to rotate, the planetary bevel gear 5 is meshed with the fixed lower bevel gear 7 from the lower part, and the planetary bevel gear 5 drives the rotary drum 6 serving as a retainer to rotate, thereby realizing the effects of second-stage speed reduction and load balancing. The drum 6 is a torque output member, which is hinged to the torsion arm 8, so as to transmit torque to the torsion arm 8, and the torsion arm 8 is driven to deflect, so as to transmit front wheel turning torque to a front wheel-mounted piston rod 9 (see fig. 1), and thus, a front wheel turning function is realized. The planetary bevel gear reduction ratio is Z2, which is of a size related to the number of teeth of the bevel gear of the input gear 3 and the lower bevel gear 7, and if the number of teeth of the bevel gear of the input gear 3 and the lower bevel gear 7 is equal, Z2 is 2.

The total reduction ratio of the mechanism is Z1 XZ 2; thus, in this example, the total reduction gear ratio of the mechanism is Z3 × 2 6.

The input gear, the rotating drum (planet carrier) and the lower bevel gear are sequentially sleeved on the outer cylinder of the landing gear strut along the axial direction, the rotating drum is used as the planet carrier of the planet gear, and the plurality of bevel gears of the planet are arranged on the rotating drum and are respectively meshed with the upper bevel gear and the lower bevel gear, so that the effects of moment amplification and load balancing are realized, the load born by a single pair of teeth is reduced, the weights of a front wheel steering actuator and a speed reducing mechanism can be obviously reduced, and the service life of the mechanism is prolonged.

Claims

1. A nose wheel steering deceleration output mechanism, wherein the input gear (3) that is fitted on the landing gear strut outer cylinder (1) is equipped with two rings of gears, form straight gear and bevel gear respectively, wherein the straight gear engages with output gear (4) of the nose wheel steering actuator (2), the planetary bevel gear (5) is installed on the tumbler (6) and is distributed evenly along the circumference of the landing gear strut outer cylinder (1), the tumbler (6) is fitted on the landing gear strut outer cylinder (1) and is hinged with the torque arm (8), the torque arm (8) outputs the front wheel deflection torque to the front tyre, the lower bevel gear (7) is fitted on the landing gear strut outer cylinder (1) and is fixed with the landing gear strut outer cylinder (1) along the circumference, the planetary bevel gear (5) engages with the bevel gear on the lower bevel gear (7) and input gear (3) respectively, form the planetary gear structure.

2. The front wheel turning reduction output mechanism according to claim 1, wherein the number of the planetary bevel gears (5) is 2 to 4.

3. The front wheel turning reduction output mechanism according to claim 2, wherein the number of the planetary bevel gears (5) is 3.

4. The nose wheel steering reduction output mechanism according to claim 1, wherein the rotary drum (6) is provided with a plurality of mounting nodes for mounting the planetary gears (5) along the circumference of the landing gear strut outer cylinder (1).

5. The nose wheel steering reduction take-off mechanism according to claim 1, wherein the lower bevel gear (7) is fixed to the landing gear strut outer tube (1) by a spline fit.

6. The front wheel turning reduction output mechanism according to claim 1, wherein the gear ratio of the spur gear of the input gear (3) and the output gear (4) is 3: 1.

7. The front wheel turning reduction output mechanism according to claim 6, wherein the number of teeth of the bevel gear of the input gear (3) is equal to that of the lower bevel gear (7).