A flexible transmission device with reverse drive and backstop

Abstract

The present invention relates to a flexible transmission device with reverse drive and backstop, belonging to the field of mechanical transmission; it includes an electric screwdriver, a torque limiter, an orthogonal transmission device, a flexible shaft, a backstop, an actuator and an aircraft cargo door; among them, the electric screwdriver is horizontally placed axially; the input shaft of the torque limiter is coaxially docked with the output shaft of the electric screwdriver; the input shaft of the orthogonal transmission device is coaxially docked with the output shaft of the torque limiter; one end of the flexible shaft is docked with the output shaft of the orthogonal transmission device, and the other end of the flexible shaft is docked with the backstop; the backstop is connected to the actuator; the actuator is connected to the aircraft cargo door; the present invention can achieve long-distance forward drive control, and the reverse drive is always in a backstop state.

Description

Technical Field

[0001] The present invention belongs to the field of mechanical transmission and relates to a flexible transmission device with reverse drive and anti-backstop function. Background Art

[0002] The actuation system of the aircraft cargo door adopts a differential scheme, which is divided into two modes: electric and manual. In both modes, a backstop is required. When in the electric mode, when the motor stops rotating, the ball screw rotates due to inertia. To ensure that the cargo door does not rotate, the output end of the backstop is subjected to a moment to perform frictional locking, thereby preventing the cargo door from descending and causing harm to personnel. When in the manual mode, the transmission flexible shaft transmits force and torque to the input end of the backstop in both clockwise and counterclockwise directions, and then reaches the manual adjustment of the opening and closing of the cargo door through the differential and the ball screw. Since the roller type backstop is prone to jamming and the single wedge type backstop has a slipping phenomenon. Summary of the Invention

[0003] The technical problem solved by the present invention is: overcoming the deficiencies of the prior art, and providing a flexible transmission device with reverse drive and anti-backstop function, which can realize long-distance forward drive control, and the reverse drive is always in the anti-backstop state.

[0004] The technical solution adopted by the present invention to solve the problem is:

[0005] A flexible transmission device with reverse drive and anti-backstop function includes an electric screwdriver, a torque limiter, an orthogonal transmission device, a flexible shaft, a backstop, an actuator and an aircraft cargo door. Among them, the electric screwdriver is horizontally placed axially; the input shaft of the torque limiter is coaxially docked with the output shaft of the electric screwdriver; the input shaft of the orthogonal transmission device is coaxially docked with the output shaft of the torque limiter; one end of the flexible shaft is docked with the output shaft of the orthogonal transmission device, and the other end of the flexible shaft is docked with the backstop; the backstop is connected to the actuator; the actuator is connected to the aircraft cargo door.

[0006] In the above-mentioned flexible transmission device with reverse drive and anti-backstop function, the rotation of the electric screwdriver drives the rotation of the torque limiter; the orthogonal transmission device converts the axial horizontal rotation motion of the torque limiter into axial vertical rotation motion, the flexible shaft rotates under the drive of the orthogonal transmission device, and the flexible shaft drives the backstop to perform rotational motion; the rotational motion of the backstop is converted into the axial horizontal movement of the actuator, so as to realize the opening or closing of the aircraft cargo door.

[0007] In the above-mentioned flexible transmission device with reverse drive and anti-backstop function, a speed adjustment knob is provided on the electric screwdriver, and the rotation speed of the output shaft of the electric screwdriver is adjusted through the speed adjustment knob.

[0008] In the above-mentioned flexible transmission device with reverse drive and anti-backstop function, the rotation speed adjustment range of the speed adjustment knob is 0 - 1900 rpm.

[0009] In the above flexible transmission device with reverse drive and backstop, a torque adjustment structure is provided on the torque limiter to adjust the transmitted torque of the torque limiter.

[0010] In the above flexible transmission device with reverse drive and backstop, the orthogonal transmission device includes an input end interface assembly and an output end interface assembly; the input end of the input end interface assembly is docked with the output end of the torque limiter; the input end of the output end interface assembly is axially orthogonally docked with the output end of the input end interface assembly; the output end of the output end interface assembly is docked with the flexible shaft.

[0011] In the above flexible transmission device with reverse drive and backstop, the backstop mainly includes an input shaft, an output shaft, a locking structure and a housing; wherein, the housing is a hollow columnar structure; the input shaft, the locking structure and the output shaft are coaxially arranged in the inner cavity of the housing in sequence; the input shaft is coaxially docked with the flexible shaft; the output shaft is docked with the actuator.

[0012] In the above flexible transmission device with reverse drive and backstop, the backstop realizes bidirectional rotational transmission of the input shaft and bidirectional rotational locking of the output shaft.

[0013] The beneficial effects of the present invention compared with the prior art are as follows:

[0014] (1) The present invention can achieve bidirectional long-distance transmission.

[0015] (2) The present invention realizes redundant setting of reverse drive and bidirectional backstop.

[0016] (3) The present invention realizes adjustable force and torque magnitude in forward transmission.

[0017] (4) The present invention adopts a matching connection of rigid and flexible devices, saving space. Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the overall docking of the flexible transmission device of the present invention;

[0019] Figure 2 It is a schematic diagram of the structure of the flexible transmission device of the present invention;

[0020] Figure 3 It is a schematic diagram of the electric screwdriver of the present invention;

[0021] Figure 4 It is a schematic diagram of the overall orthogonal transmission device of the present invention;

[0022] Figure 5 It is a schematic diagram of the input end interface assembly of the present invention;

[0023] Figure 6 It is a schematic diagram of the output end interface assembly of the present invention;

[0024] Figure 7 This is the structural diagram of the backstop of the present invention;

[0025] Figure 8 This is the schematic diagram of the reverse locking principle of the backstop of the present invention. Detailed implementation manners

[0026] The present invention will be further described below in conjunction with embodiments.

[0027] The present invention provides a flexible transmission device for reverse drive backstop, which can realize forward drive control over a long distance, and the reverse drive is always in a backstop state.

[0028] The flexible transmission device for reverse drive backstop, as Figure 1 shown, includes an electric screwdriver 1, a torque limiter 2, an orthogonal transmission device 3, a flexible shaft 4, a backstop 5, an actuator 6 and an aircraft cargo door 7; wherein, the electric screwdriver 1 is horizontally placed axially; the input shaft of the torque limiter 2 is coaxially docked with the output shaft of the electric screwdriver 1; the input shaft of the orthogonal transmission device 3 is coaxially docked with the output shaft of the torque limiter 2; one end of the flexible shaft 4 is docked with the output shaft of the orthogonal transmission device 3, and the other end of the flexible shaft 4 is docked with the backstop 5; the backstop 5 is connected with the actuator 6; the actuator 6 is connected with the aircraft cargo door 7.

[0029] Working process: As Figure 2 shown, the rotation of the electric screwdriver 1 drives the rotation of the torque limiter 2; the orthogonal transmission device 3 converts the axially horizontal rotational motion of the torque limiter 2 into an axially vertical rotational motion, the flexible shaft 4 rotates driven by the orthogonal transmission device 3, and the flexible shaft 4 drives the backstop 5 to perform a rotational motion; the rotational motion of the backstop 5 is converted into the axially horizontal movement of the actuator 6, so as to realize the opening or closing of the aircraft cargo door 7.

[0030] When the transmission device is in forward drive, first start the electric screwdriver 1 to transmit force and torque to the torque limiter 2, then to the manual tool interface component end of the input end of the orthogonal transmission device 3, and then drive the flexible shaft 4 through the orthogonal transmission device 3, and the input end of the backstop 5 controls the forward movement of the actuator 6.

[0031] When the transmission device is in reverse drive, on the one hand, since the output end of the backstop 5 is always in a reverse drive locking state, the force and torque cannot be reversely transmitted through the flexible shaft 4 to the output end of the orthogonal transmission device 3; on the other hand, the output end of the orthogonal transmission device 3 has the function of reverse drive backstop and cannot further transmit the force and torque to the input end of the orthogonal transmission device 3. Therefore, the double backstop function of the reverse drive of the device is realized.

[0032] The electric screwdriver has two speed gears. The speed range of the first gear is 0 - 500 rpm, and the speed range of the second gear is 0 - 1900 rpm. The electric screwdriver is an auxiliary tool. As Figure 3 shown, a speed adjustment knob 1-1 is provided on the electric screwdriver 1, and the rotation speed of the output shaft of the electric screwdriver 1 is adjusted through the speed adjustment knob 1-1.

[0033] A torque adjustment structure is provided on the torque limiter 2 to adjust the transmitted torque of the torque limiter 2. When the torque value transmitted by the electric screwdriver 1 is less than the set torque value, the steel balls of the torque limiter 2 are in a normal meshing state; when the torque value transmitted by the electric screwdriver is greater than the set torque value, at this time the steel balls of the torque limiter 2 slide out of the groove. After eliminating the overload, under the residual acting force of the spring, the steel balls automatically reset at the next position, thereby realizing the limitation of the torque value. The torque limiter 2 is an auxiliary tool for providing a safe working condition.

[0034] As Figure 4 shown, the orthogonal transmission device 3 includes an input end interface assembly 3-1 and an output end interface assembly 3-2; the input end of the input end interface assembly 3-1 is docked with the output end of the torque limiter 2; the input end of the output end interface assembly 3-2 is axially orthogonally docked with the output end of the input end interface assembly 3-1; the output end of the output end interface assembly 3-2 is docked with the flexible shaft 4.

[0035] As Figure 5 shown, the input end interface assembly 3-1 mainly includes an input bevel gear shaft 3-1-1, an input end bevel gear 3-1-2, a slider 3-1-3, an input bearing cover plate 3-1-4, a transition piece 3-1-5, a spring 3-1-6, a deep groove ball bearing 3-1-7, a flat key 3-1-8 and an O-ring 3-1-9.

[0036] The prerequisite for the forward transmission of the input end interface assembly 3-1 of the orthogonal transmission device is that the electric screwdriver pushes the slider 3-1-3 to disengage from the input bearing cover plate 3-1-4, and then pushes the spring 3-1-6 to the compressed state and contacts the transition piece 3-1-5. At this time, the electric screwdriver can transmit the force and torque to the input end interface assembly 3-1 of the orthogonal transmission device, and further transmit the force and torque to the output end interface assembly 3-2 of the orthogonal transmission device. The outer shapes of the output bearing cover plate 3-1-4 and the slider 3-1-3 are hexagonal, and the outer shape structure is not limited to hexagonal.

[0037] As Figure 6 shown, the output end interface assembly 3-2 mainly includes an output bevel gear shaft 3-2-1, an output end bevel gear 3-2-2, a connecting plate 3-2-3, an output bearing cover plate 3-2-4, a flat key 3-2-5, a deep groove ball bearing 3-2-6 and an O-ring 3-2-7;

[0038] The principle of reverse locking of the output end interface component 3-2 of the orthogonal transmission device is as follows: When the output end of the orthogonal transmission device is subjected to torque, the output bevel gear shaft 3-2-1 drives the output bevel gear 3-2-2 to rotate through the flat key 3-2-5, and the input bevel gear 3-2-2 of the orthogonal transmission device rotates accordingly. At this time, the rotation of the input bevel gear shaft drives its compression spring 3-1-6 to recover to its original length, and pushes the slider 3-1-3 to contact the input bearing cover 3-1-4, and always maintains the contact until the slider 3-1-3 and the input bearing cover 3-1-4 are in a locked state. Therefore, when the output end of the orthogonal transmission device rotates, the input end of the orthogonal transmission device is in a locked state.

[0039] As Figure 7 shown, the backstop 5 mainly includes an input shaft 5-1, an output shaft 5-2, a locking structure 5-3, a housing 5-4, a deep groove ball bearing 5-5 and a gasket 5-6; wherein, the housing 5-4 is a hollow cylindrical structure; the input shaft 5-1, the locking structure 5-3 and the output shaft 5-2 are coaxially arranged in the inner cavity of the housing 5-4 in sequence; the input shaft 5-1 is coaxially butted with the flexible shaft 4; the output shaft 5-2 is butted with the actuator 6. The backstop 5 realizes the bidirectional rotational transmission of the input shaft 5-1 and the bidirectional rotational locking of the output shaft 5-2.

[0040] Figure 8 is the schematic diagram of the reverse locking principle of the backstop 5. The contact points of the roller with the housing and the output shaft are two points A and B. The supporting forces of the contact points A and B are N1 and N2 respectively, and the frictional forces are f1N1 and f2N2 respectively. By establishing the equilibrium equation, the self-locking condition of the roller is obtained as: α ≤ 2ρ c . Where α is the wedge angle of the roller and ρ c is the friction angle.

[0041] Although the present invention has been disclosed above with preferred embodiments, it is not used to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and decorations made to the above embodiments according to the technical essence of the present invention without departing from the technical solution of the present invention all fall within the protection scope of the technical solution of the present invention.

Claims

1. A flexible transmission device with reverse drive and backstop, characterized in that: It includes an electric screwdriver (1), a torque limiter (2), an orthogonal transmission device (3), a flexible shaft (4), a backstop (5), an actuator (6) and an aircraft cargo door (7); among them, the electric screwdriver (1) is horizontally placed axially; the input shaft of the torque limiter (2) is coaxially butted with the output shaft of the electric screwdriver (1); the input shaft of the orthogonal transmission device (3) is coaxially butted with the output shaft of the torque limiter (2); one end of the flexible shaft (4) is butted with the output shaft of the orthogonal transmission device (3), and the other end of the flexible shaft (4) is butted with the backstop (5); the backstop (5) is connected to the actuator (6); the actuator (6) is connected to the aircraft cargo door (7).

2. The flexible transmission device with reverse drive and backstop according to claim 1, characterized in that: The rotation of the electric screwdriver (1) drives the rotation of the torque limiter (2); the orthogonal transmission device (3) converts the axially horizontal rotational motion of the torque limiter (2) into an axially vertical rotational motion, the flexible shaft (4) rotates under the drive of the orthogonal transmission device (3), and the flexible shaft (4) drives the backstop (5) to perform a rotational motion; the rotational motion of the backstop (5) is converted into the axially horizontal movement of the actuator (6), realizing the opening or closing of the aircraft cargo door (7).

3. The flexible transmission device with reverse drive and backstop according to claim 1, characterized in that: A speed adjustment knob (1-1) is provided on the electric screwdriver (1), and the rotation speed of the output shaft of the electric screwdriver (1) is adjusted through the speed adjustment knob (1-1).

4. The flexible transmission device with reverse drive and backstop according to claim 3, characterized in that: The rotation speed adjustment range of the speed adjustment knob (1-1) is 0-1900 rpm.

5. The flexible transmission device with reverse drive and backstop according to claim 1, characterized in that: A torque adjustment structure is provided on the torque limiter (2) to realize the adjustment of the transmitted torque of the torque limiter (2).

6. The flexible transmission device with reverse drive and backstop according to claim 1, characterized in that: The orthogonal transmission device (3) includes an input end interface component (3-1) and an output end interface component (3-2); the input end of the input end interface component (3-1) is butted with the output end of the torque limiter (2); the input end of the output end interface component (3-2) is axially orthogonally butted with the output end of the input end interface component (3-1); the output end of the output end interface component (3-2) is butted with the flexible shaft (4).

7. The flexible transmission device with reverse drive and backstop according to claim 1, characterized in that: The backstop (5) mainly includes an input shaft (5-1), an output shaft (5-2), a locking structure (5-3) and a housing (5-4); among them, the housing (5-4) is a hollow columnar structure; the input shaft (5-1), the locking structure (5-3) and the output shaft (5-2) are coaxially arranged in the inner cavity of the housing (5-4) in sequence; the input shaft (5-1) is coaxially butted with the flexible shaft (4); the output shaft (5-2) is butted with the actuator (6).

8. The flexible transmission device with reverse drive and backstop according to claim 1, characterized in that: The backstop (5) realizes the two-way rotational transmission of the input shaft (5-1) and the two-way rotational locking of the output shaft (5-2).

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