CN120288235A - Helicopter landing gear retracting and extending system and helicopter landing gear - Google Patents
Helicopter landing gear retracting and extending system and helicopter landing gear Download PDFInfo
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- CN120288235A CN120288235A CN202510615666.6A CN202510615666A CN120288235A CN 120288235 A CN120288235 A CN 120288235A CN 202510615666 A CN202510615666 A CN 202510615666A CN 120288235 A CN120288235 A CN 120288235A
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- way valve
- buffer
- landing gear
- hydraulically controlled
- pressure
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Abstract
The invention provides a helicopter landing gear retraction system and a helicopter landing gear, which comprise a buffer (9) and a retraction cylinder (3), wherein a retraction piston (10) and a piston rod (8) are arranged in the buffer (9), the retraction piston (10) is used for dividing the buffer (9) into a left cavity (12) and a right cavity (11), the piston rod (8) is connected with a wheel or a rocker arm, the right cavity (11) is used for receiving oil of a hydraulic system, the retraction piston (10) is driven by the oil of the hydraulic system to move so as to drive the piston rod (8) to move, the retraction cylinder (3) is internally provided with the piston (2) so as to form an upper cavity (1) and a lower cavity (4), the upper cavity (1) is communicated with the left cavity (12) of the buffer (9) and is used for storing the oil transferred when the buffer (9) is retracted, and the cross section of the lower cavity (4) is smaller than that of the upper cavity (1).
Description
Technical Field
The invention relates to the field of helicopter landing gears, in particular to a helicopter landing gear retraction system and a helicopter landing gear.
Background
In order to reduce air resistance in flight, increase voyage and improve economy of civil medium-and-large-sized transport helicopters, retractable landing gear is often adopted.
Usually, when flying in the air, the landing gear can be retracted and hidden in the fuselage, and before landing, the landing gear can be put down, so that the helicopter can safely land. For helicopters that employ hydraulic energy for the secondary energy source, hydraulically driven landing gear retraction and deployment is typically used.
For the strut type undercarriage, a retractable actuator cylinder can be additionally arranged for retraction, one end of the retractable actuator cylinder is arranged on the machine body structure, and the other end of the retractable actuator cylinder is connected to the buffer. The rams typically require a large retraction space and add additional weight. For a helicopter with a compact structure, enough retraction space is not available, and a landing gear with a retraction actuator cannot be arranged;
for the rocker-arm landing gear, the retraction and the extension of the retraction jack are difficult to be carried out in a mode of additionally installing the retraction jack due to structural limitation;
in summary, the helicopter landing gear retraction system needs to solve the following two problems:
1. The landing gear is retracted and released in a small space;
2. landing gear suitable for rocker arm is provided.
Disclosure of Invention
The invention provides a helicopter undercarriage retraction system and a helicopter undercarriage, which solve the problem that the existing undercarriage retraction system cannot be applied to an aircraft with structural limitation.
A first aspect of the invention provides a helicopter landing gear retraction system comprising a buffer 9 and a retraction cylinder 3, wherein,
A retractable piston 10 and a piston rod 8 are arranged in the buffer 9, the retractable piston 10 divides the buffer 9 into a left cavity 12 and a right cavity 11, and the piston rod 8 is connected with a machine wheel or a rocker arm;
The right cavity 11 is used for receiving oil of the hydraulic system, and the retractable piston 10 is driven by the oil of the hydraulic system to move so as to drive the piston rod 8 to move;
a piston 2 is arranged in the retraction cylinder 3 to form an upper cavity 1 and a lower cavity 4, the upper cavity 1 is communicated with a left cavity 12 of the buffer 9 and is used for storing oil transferred when the buffer 9 is retracted, and the lower cavity 4 is used for receiving oil of a hydraulic system;
the cross section area of the lower cavity 4 is small the cross-sectional area of the upper chamber 1.
Alternatively, the cross-sectional area of the lower chamber 4 is half the cross-sectional area of the upper chamber 1.
Optionally, the helicopter landing gear retraction system further comprises a first hydraulic control one-way valve 15, a second hydraulic control one-way valve 14 and a third hydraulic control one-way valve 7;
the control end of the first hydraulic control check valve 15, the control end of the second hydraulic control check valve 14 and the connection end of the third hydraulic control check valve 7 are connected with the retraction pressure supply port 6 of the hydraulic system;
the control end of the third hydraulic control one-way valve 7 and the lower cavity 4 of the retraction cylinder 3 are connected with a retraction pressure supply port 5 of the hydraulic system;
The connection end of the first hydraulic control one-way valve 15 is connected with the upper cavity 1 of the receiving oil discharging cylinder 3, the cut-off end of the first hydraulic control one-way valve 15 is connected with the connection end of the second hydraulic control one-way valve 14, and the cut-off end of the second hydraulic control one-way valve 14 is connected with the left cavity 12 of the buffer 9;
The cut-off end of the third hydraulic control one-way valve 7 is connected with the right cavity 11 of the buffer 9.
Optionally, the helicopter landing gear retraction system further comprises a pressure sensor 13;
a pressure sensor 13 for monitoring the oil pressure P in the left chamber 12 of the damper 9.
Optionally, when P is more than or equal to a first preset pressure P1, generating a first indication signal, wherein the first indication signal is used for indicating that landing gear can be normally landed, and the landing gear does not need to be checked after landing;
When P1> P is more than or equal to a second preset pressure P2, generating a second indication signal, wherein the second indication signal is used for indicating that the landing sinking speed is required to be smaller than the preset speed, and checking the landing gear after landing;
when P < P2, generating a third indication signal, wherein the third indication signal is used for indicating that landing is completed by means of an external facility, and checking the landing gear after landing;
Wherein the first preset pressure P1 is greater than the second preset pressure P2.
A second aspect of the invention provides a helicopter landing gear employing a helicopter landing gear retraction system as claimed in any of the first aspects.
The invention provides a helicopter landing gear retraction system and a helicopter landing gear, which enable a helicopter to retract and retract the landing gear more safely and are suitable for helicopters with limited structures.
1) The volume of oil required by the landing gear to be put down is half of the volume of oil required by the landing gear to be folded;
2) According to the invention, the oil in the landing gear is isolated from the oil in the retraction system;
3) The invention adopts a hydraulic control one-way valve as an upper lock and a lower lock;
4) The invention performs double redundancy design on the lower lock;
5) The pressure sensor is used for monitoring the pressure of the inner cavity of the undercarriage;
6) The invention generates an indication signal to prompt landing risk.
Drawings
FIG. 1 is a schematic diagram of the components and principles of a helicopter landing gear retraction system provided by the present invention;
reference numerals illustrate:
1. The hydraulic control device comprises an upper cavity 2 of a retraction cylinder, a piston 3 of the retraction cylinder, a retraction cylinder 4, a lower cavity 5 of the retraction cylinder, a lowering pressure supply port 6, a retraction pressure supply port, a third hydraulic control check valve 8, a buffer piston rod 9, a buffer 10, a retraction piston 11, a right buffer cavity 12, a left buffer cavity 13, a pressure sensor 14, a second hydraulic control check valve 15 and a first hydraulic control check valve.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without making any inventive effort are intended to fall within the scope of the present invention.
Features and exemplary embodiments of various aspects of the invention are described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by showing examples of the invention. The present invention is in no way limited to any particular arrangement and method set forth below, but rather covers any adaptations, alternatives, and modifications of structure, method, and device without departing from the spirit of the invention. In the drawings and the following description, well-known structures and techniques have not been shown in detail in order not to unnecessarily obscure the present invention.
It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other, and the embodiments may be referred to and cited with each other. The invention will be described in detail below with reference to the drawings in connection with embodiments.
The present invention will be described in further detail with reference to examples and drawings, but embodiments of the present invention are not limited thereto.
As shown in fig. 1, the present invention provides a helicopter landing gear retraction system, comprising a buffer 9 and a retraction cylinder 3, wherein,
A retractable piston 10 and a piston rod 8 are arranged in the buffer 9, the retractable piston 10 divides the buffer 9 into a left cavity 12 and a right cavity 11, and the piston rod 8 is connected with a machine wheel or a rocker arm;
The right cavity 11 is used for receiving oil of the hydraulic system, and the retractable piston 10 is driven by the oil of the hydraulic system to move so as to drive the piston rod 8 to move;
a piston 2 is arranged in the retraction cylinder 3 to form an upper cavity 1 and a lower cavity 4, the upper cavity 1 is communicated with a left cavity 12 of the buffer 9 and is used for storing oil transferred when the buffer 9 is retracted, and the lower cavity 4 is used for receiving oil of a hydraulic system;
the cross section area of the lower cavity 4 is small the cross-sectional area of the upper chamber 1.
Alternatively, the cross-sectional area of the lower chamber 4 is half the cross-sectional area of the upper chamber 1.
Optionally, the helicopter landing gear retraction system further comprises a first hydraulic control one-way valve 15, a second hydraulic control one-way valve 14 and a third hydraulic control one-way valve 7;
the control end of the first hydraulic control check valve 15, the control end of the second hydraulic control check valve 14 and the connection end of the third hydraulic control check valve 7 are connected with the retraction pressure supply port 6 of the hydraulic system;
the control end of the third hydraulic control one-way valve 7 and the lower cavity 4 of the retraction cylinder 3 are connected with a retraction pressure supply port 5 of the hydraulic system;
The connection end of the first hydraulic control one-way valve 15 is connected with the upper cavity 1 of the receiving oil discharging cylinder 3, the cut-off end of the first hydraulic control one-way valve 15 is connected with the connection end of the second hydraulic control one-way valve 14, and the cut-off end of the second hydraulic control one-way valve 14 is connected with the left cavity 12 of the buffer 9;
The cut-off end of the third hydraulic control one-way valve 7 is connected with the right cavity 11 of the buffer 9.
Optionally, the helicopter landing gear retraction system further comprises a pressure sensor 13;
a pressure sensor 13 for monitoring the oil pressure P in the left chamber 12 of the damper 9.
Optionally, when P is more than or equal to a first preset pressure P1, generating a first indication signal, wherein the first indication signal is used for indicating that landing gear can be normally landed, and the landing gear does not need to be checked after landing;
When P1> P is more than or equal to a second preset pressure P2, generating a second indicating signal, wherein the second indicating signal is used for indicating that the landing sinking speed is less than the preset speed, and checking the landing gear after landing;
when P < P2, generating a third indication signal, wherein the third indication signal is used for indicating that landing is completed by means of an external facility, and checking the landing gear after landing;
Wherein the first preset pressure P1 is greater than the second preset pressure P2.
Illustratively, the present invention proposes a helicopter landing gear retraction system. The system comprises a buffer 9, a retraction cylinder 3, a pressure sensor 13, a first hydraulic control one-way valve 15, a second hydraulic control one-way valve 14 and a third hydraulic control one-way valve 7, wherein the retraction system is shown in figure 1.
For example, the buffer 9 may be a buffer as in patent ZL 201711256532.1.
The landing gear retraction principle is as shown in fig. 1:
After receiving a retraction instruction, the hydraulic system supplies pressure to the retraction pressure supply port 6, hydraulic pressure supplies pressure to the buffer 9 and the right cavity 11 through the third hydraulic control one-way valve 7 to push the piston rod 8 of the buffer 9 to retract upwards, meanwhile, the hydraulic pressure is connected with the first hydraulic control one-way valve 15 and the second hydraulic control one-way valve 14 through the hydraulic control end, compressed oil in the left cavity 12 of the buffer 9 flows into the upper cavity 1 of the retraction cylinder 3 through the first hydraulic control one-way valve 15 and the second hydraulic control one-way valve 14 and pushes the piston 2 of the retraction cylinder 3 to move downwards, and oil in the lower cavity 4 of the retraction cylinder 3 flows back to the hydraulic system through the retraction pressure supply port 5;
After receiving the lowering instruction, the hydraulic system supplies pressure to the lowering pressure supply port 5, hydraulic pressure flows into the lower cavity 4 of the retraction cylinder 3 to push the piston 2 of the retraction cylinder 3 to move upwards, compressed oil in the upper cavity 1 of the retraction cylinder 3 flows into the left cavity 12 of the buffer 9 through the first hydraulic control check valve 15 and the second hydraulic control check valve 14, meanwhile, the hydraulic pressure is connected with the third hydraulic control check valve 7 through the hydraulic control end, compressed oil in the left cavity 12 of the buffer 9 pushes the piston rod 8 of the buffer 9 to move downwards, and oil in the right cavity 11 of the buffer 9 flows back into the hydraulic system through the third hydraulic control check valve 7 and the retraction pressure supply port 6.
The buffer 9 adopts a buffer such as the one in patent ZL201711256532.1, and comprises a low-pressure air cavity, a high-pressure air cavity and an oil cavity, so that two-stage energy absorption can be realized, and various landing speed requirements can be met, meanwhile, the buffer 9 comprises a retraction and lowering oil inlet port and a retraction and lowering piston 10, and when external pressure is supplied, the retraction or lowering of the piston rod 8 of the buffer 9 can be realized, so that the retraction or lowering of the landing gear can be realized.
The upper cavity 1 of the retraction cylinder 3 is used for storing the oil transferred when the buffer 9 is retracted, the lower cavity 4 is used for receiving the oil of a hydraulic system, the upper cavity 1 and the lower cavity 4 are isolated by the piston 2, and the oil in the buffer 9 can be prevented from being mixed with the oil of the hydraulic system, so that the two sides are not affected by each other. Meanwhile, the sectional area of the lower cavity 4 is smaller than that of the upper cavity 1, and the landing gear can be put down by using less oil liquid by the hydraulic system under the same actuating stroke. When oil leakage exists in the hydraulic system, the lower the oil needed for landing gear to be put down, the higher the safety of the landing gear to be put down.
After the landing gear is retracted, an upper lock is required to lock the landing gear in the retracted position, and after the landing gear is lowered, a lower lock is required to lock the landing gear in the lowered position. From the viewpoint of functional safety, the reliability requirement for the lower lock is higher. The upper lock and the lower lock are both hydraulic locks, and are different from common mechanical locks. The upper lock adopts a third hydraulic control one-way valve 7, and the lower lock adopts a first hydraulic control one-way valve 15 and a second hydraulic control one-way valve 14 which are connected in series to improve the reliability. When the landing gear is in the retracted position, the oil in the right cavity 11 of the buffer 9 cannot flow back to the hydraulic system due to the blocking effect of the third hydraulic check valve 7, so that the landing gear piston rod 8 is kept in the retracted position under the action of the oil pressure in the right cavity 11 of the buffer 9, and when the landing gear is in the lowered position, the oil in the left cavity 12 of the buffer 9 cannot flow back to the hydraulic system due to the blocking effect of the first hydraulic check valve 15 and the second hydraulic check valve 14, so that the left cavity 12 forms a closed oil cavity. The landing gear piston rod 8 is held in the lowered position under the pressure of the left chamber 12 of the damper 9.
When the landing gear is retracted, part of oil in the left cavity 12 of the buffer 9 is transferred to the upper cavity 1 of the retraction cylinder 3, and when the landing gear is lowered, the part of oil is transferred back to the left cavity 12 of the buffer 9 from the upper cavity 1 of the retraction cylinder 3. The oil path between the left cavity 12 of the buffer 9 and the upper cavity 1 of the retraction cylinder 3 is complex, and more leakage points are caused, so that the oil transferred back to the left cavity 12 of the buffer 9 when the retraction cylinder is put down is possibly reduced. In addition, if the piston 2 of the retraction cylinder 3 has a clamping failure, the oil transferred back to the left cavity 12 of the buffer 9 is reduced. This condition will result in a reduced pressure in the landing gear cavity, which will have a reduced ability to absorb landing energy and will not support the helicopter in severe cases. In view of the characteristics, the invention adds the pressure sensor 13 in the oil way for monitoring the oil pressure of the left cavity 12 of the buffer 9, as shown in fig. 1. Based on the monitored pressure values, the state of the landing gear is divided into three and three different indication signals are generated.
When P is more than or equal to a first preset pressure P1, generating a first indication signal, wherein the first indication signal is used for indicating that landing gear can be normally landed, and the landing gear does not need to be checked after landing;
When P1> P is more than or equal to a second preset pressure P2, generating a second indication signal, wherein the second indication signal is used for indicating that the landing sinking speed is required to be smaller than the preset speed, and checking the landing gear after landing;
When P < P2, a third indication signal is generated, the third indication signal is used for indicating that landing is required to be completed by means of external facilities, and the landing gear is inspected after landing.
The above description is merely a further embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art will be able to apply equivalents and modifications according to the technical solution and the concept of the present invention within the scope of the present invention disclosed in the present invention.
Claims (9)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202510615666.6A CN120288235A (en) | 2025-05-14 | 2025-05-14 | Helicopter landing gear retracting and extending system and helicopter landing gear |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202510615666.6A CN120288235A (en) | 2025-05-14 | 2025-05-14 | Helicopter landing gear retracting and extending system and helicopter landing gear |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN120288235A true CN120288235A (en) | 2025-07-11 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202510615666.6A Pending CN120288235A (en) | 2025-05-14 | 2025-05-14 | Helicopter landing gear retracting and extending system and helicopter landing gear |
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| CN (1) | CN120288235A (en) |
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- 2025-05-14 CN CN202510615666.6A patent/CN120288235A/en active Pending
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