Aviation propeller pitch changing mechanism and aircraft

Abstract

The utility model provides an aviation propeller pitch changing mechanism which comprises a propeller hub, a shifting sleeve assembly capable of moving up and down and a plurality of propeller shafts arranged around the circumference of the shifting sleeve assembly in an array mode are arranged in the propeller hub, an eccentric pin shaft is arranged at the end of each propeller shaft, and a sliding block assembly is fixedly connected to the eccentric pin shaft. The shifting sleeve assembly is provided with a sliding groove allowing the sliding block assembly to horizontally move, the sliding groove comprises two end faces arranged in a spaced mode, the end faces can move in a lifting mode so that the width of the sliding groove can be adjusted, the sliding groove can be matched with the height of the sliding block assembly, and by adjusting the distance between the two end faces, the sliding groove can be matched with the height of the sliding block assembly. The sliding block assembly and the sliding groove are in zero clearance fit, it is guaranteed that all the blades are located at the same pitch angle, and the situation that the working stability and safety of the propeller are affected due to the fact that the blades shake in the rotating process is avoided.

Description

Technical Field

[0001] This utility model relates to the field of aircraft technology, specifically to an aircraft propeller pitch control mechanism and an aircraft. Background Technology

[0002] Aircraft need to adjust the angle of their propeller blades to operate at the optimal blade angle under different flight conditions, thereby improving propulsion efficiency. For example, during takeoff, to obtain maximum thrust, the blade angle is adjusted to a larger angle to provide sufficient thrust for the aircraft to quickly leave the ground. During cruise or landing, the blade angle is adjusted to a smaller angle to reduce drag or improve maneuverability. This change in blade angle is called propeller pitch control.

[0003] When the propeller operates with variable pitch, the blade angle is adjusted by the up-and-down movement of the shift sleeve assembly. The eccentric pin of the propeller shaft is connected to the shift sleeve assembly via a slider assembly, allowing the slider assembly to move horizontally, thereby rotating the propeller shaft and thus changing the blade pitch. The gap between the slider assembly and the groove has a significant impact on the propeller's operational stability. If there is a gap between the slider assembly and the groove, the slider assembly will have free space to move in the vertical direction, which may cause the blades to have a free rotation angle even when the pitch is not changed. Therefore, it is difficult to ensure that all blades are at the same pitch angle when the propeller is rotating. This not only reduces the propeller's efficiency but may also cause the blades to wobble during rotation, affecting stability and safety. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to propose an aviation propeller pitch-changing mechanism and aircraft to solve the problems mentioned in the background section above.

[0005] This utility model is achieved through the following technical solution:

[0006] An aircraft propeller pitch control mechanism includes a propeller hub, inside which is a movable shift sleeve assembly, and several propeller shafts arranged in a circumferential array around the shift sleeve assembly. Each propeller shaft has an eccentric pin at its end, and a slider assembly is fixedly connected to the eccentric pin. The shift sleeve assembly has a groove for horizontal movement of the slider assembly. The groove includes two spaced-apart end faces, which are movable up and down to adjust the width of the groove so that it adapts to the height of the slider assembly.

[0007] Furthermore, the shift sleeve assembly includes a shift sleeve body, a first washer, a screw, and a first self-locking nut. The shift sleeve body is provided with a mounting groove, the first washer is disposed in the mounting groove, the screw passes through the shift sleeve body and abuts the first washer, the first self-locking nut is sleeved on the screw and abuts the shift sleeve body, and the surface of the first washer that abuts against the slider assembly constitutes one of the end faces.

[0008] Furthermore, the lever assembly also includes a second washer, which is fixed in the mounting groove and detachably connected to the lever body. The surface of the second washer that abuts against the slider assembly forms one of the end faces.

[0009] Furthermore, the sleeve body is provided with a plurality of blind holes, and the first gasket is provided with a positioning pin that is embedded in the blind holes.

[0010] Furthermore, the second washer is provided with a countersunk hole, and the shift sleeve assembly also includes a second countersunk bolt inserted into the countersunk hole, and a second self-locking nut. The second countersunk bolt passes through the second washer and the shift sleeve body and is connected to the second self-locking nut.

[0011] Furthermore, the slider assembly includes a slider body and a plurality of balls. The upper and lower surfaces of the slider body are provided with a plurality of elongated grooves, and the balls are disposed in the elongated grooves and abut against the end face.

[0012] Furthermore, the long groove penetrates the slider body and forms an opening, the ball is inserted into the long groove through the opening, and the slider assembly also includes a baffle for sealing the opening, the baffle being fixedly connected to the slider body.

[0013] Furthermore, the slider assembly also includes a first countersunk bolt, which passes through the baffle and is connected to the slider body.

[0014] Furthermore, the eccentric pin is connected to the slider assembly via a flat-head bolt or a resilient retaining ring.

[0015] On the other hand, this utility model provides an aircraft including an aviation propeller pitch control mechanism as described in any of the preceding claims.

[0016] The beneficial effects of this utility model are as follows: A variable pitch mechanism for an aircraft propeller includes a hub, inside which is a movable shift sleeve assembly. Several propeller shafts are arranged in a circumferential array around the shift sleeve assembly. An eccentric pin is provided at the end of each propeller shaft, and a slider assembly is fixedly connected to the eccentric pin. The shift sleeve assembly has a groove for the horizontal movement of the slider assembly. The groove includes two spaced end faces, which can be raised and lowered to adjust the width of the groove so that the groove matches the height of the slider assembly. By adjusting the distance between the two end faces, the groove matches the height of the slider assembly. The slider assembly and the groove have a zero-clearance fit, ensuring that all blades are at the same pitch angle, preventing the blades from wobbling during rotation, which would affect the stability and safety of the propeller operation. Attached Figure Description

[0017] Figure 1 A three-dimensional view of a partial assembly of an aircraft propeller pitch control mechanism.

[0018] Figure 2 A perspective view of the assembly of the gear sleeve assembly, propeller shaft, and slider assembly.

[0019] Figure 3 This is a three-dimensional view of the dial sleeve body.

[0020] Figure 4 This is a three-dimensional view of the first gasket.

[0021] Figure 5 This is a three-dimensional view of the second gasket.

[0022] Figure 6 A 3D view of the propeller shaft and slider assembly.

[0023] Figure 7 This is a 3D view of the slider body and the ball bearing assembly.

[0024] The above figures include the following reference numerals:

[0025] 1. Propeller hub; 2. Gear assembly; 21. Gear body; 211. Mounting groove; 212. Blind hole; 213. Threaded through hole; 22. First washer; 221. Locating pin; 23. Screw; 24. First self-locking nut; 25. Second washer; 251. Countersunk hole; 26. Second countersunk bolt; 27. Second self-locking nut; 28. Slide groove; 3. Propeller shaft; 31. Eccentric pin; 4. Slider assembly; 41. Slider body; 411. Long groove; 412. Threaded hole; 42. Ball bearing; 43. Baffle; 44. First countersunk bolt; 5. Variable pitch motor; 6. Lead screw; 7. Flat head bolt. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is intended to aid in understanding this utility model, but does not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0027] Reference Figures 1 to 7 As shown, an aircraft propeller pitch control mechanism includes a hub 1, a movable shift sleeve assembly 2 inside the hub 1, and several propeller shafts 3 arranged in a circumferential array around the shift sleeve assembly 2. One end of the propeller shaft 3 is connected to the propeller blade, and the other end of the propeller shaft 3 is provided with an eccentric pin 31. The eccentric pin 31 is fixedly connected to a slider assembly 4. The shift sleeve assembly 2 is provided with a groove 28 for the slider assembly 4 to move horizontally. The groove 28 includes two spaced end faces that can be raised and lowered to adjust the width of the groove 28 so that the groove 28 can be adapted to the height of the slider assembly 4.

[0028] This invention adjusts the distance between the two end faces to make the slide groove 28 fit the height of the slider assembly 4. The slider assembly 4 and the slide groove 28 are in a zero-clearance fit, ensuring that all blades are at the same pitch angle, thus avoiding the blades from shaking during rotation, which would affect the stability and safety of the propeller operation.

[0029] There are various structures for driving the shift sleeve assembly 2 to move up and down. In this utility model, it also includes a variable pitch motor 5 and a lead screw 6. The variable pitch motor 5 drives the lead screw 6 to rotate, and the shift sleeve assembly 2 is sleeved on the lead screw 6. The rotation of the lead screw 6 drives the shift sleeve assembly 2 to move up and down. As an alternative embodiment, the shift sleeve assembly 2 can be driven to move up and down by a cylinder or the like.

[0030] Specifically, this utility model achieves adjustable height and movement of the end face through the following structure:

[0031] Reference Figures 2 to 5 As shown, the shift sleeve assembly 2 includes a shift sleeve body 21, a first washer 22, a screw 23, and a first self-locking nut 24. The shift sleeve body 21 is provided with a mounting groove 211. The first washer 22 is disposed in the mounting groove 211. The screw 23 passes through the shift sleeve body 21 and supports the first washer 22. The first self-locking nut 24 is sleeved on the screw 23 and supports the shift sleeve body 21. The surface of the first washer 22 that abuts against the slider assembly 4 forms one of its end faces.

[0032] Therefore, by adjusting the screw 23 into the sleeve body 21, the screw 23 pushes the upper surface of the first washer 22, causing the lower surface of the first washer 22 to abut against the slider assembly 4, achieving a zero-clearance fit between the slider assembly 4 and the slide groove 28. This greatly reduces the processing difficulty, improves the ease of assembly, and ensures the stability and safety of the propeller during operation.

[0033] The sleeve body 21 is provided with several blind holes 212, and the first gasket 22 is provided with a positioning pin 221 that is embedded in the blind holes 212. The blind holes 212 and the positioning pin 221 cooperate to pre-install and position the first gasket 22 and guide it during up and down movement adjustment.

[0034] The shift sleeve body 21 has four threaded through holes 213 symmetrically arranged on both sides of the blind hole 212. The number of threaded through holes 213 can also be set to multiple. The threaded through holes 213 cooperate with the screw 23. The first washer 22 is inserted into the mounting groove 211 and the positioning pin 221 is embedded into the blind hole 212 to complete the pre-assembly. The propeller shaft 3 and the slider assembly 4 are pre-assembled. Then the slider assembly 4 is inserted into the slide groove 28 and the screw 23 is tightened. At this time, the bottom of the screw 23 contacts the upper surface of the first washer 22. The gap between the slider assembly 4 and the slide groove 28 is adjusted by adjusting the screw 23. When the slider assembly 4 can slide smoothly horizontally left and right in the slide groove 28 without any gap, the screw 23 and the shift sleeve body 21 are locked with the first self-locking nut 24.

[0035] To prevent wear caused by direct contact between the slider assembly 4 and the shift sleeve body 21, and for maintenance cost considerations, the shift sleeve assembly 2 also includes a second washer 25. The second washer 25 is fixed in the mounting groove 211 and is detachably connected to the shift sleeve body 21. The surface of the second washer 25 that abuts against the slider assembly 4 forms one end face. The first washer 22 and the second washer 25 can be made of high-hardness, high-wear-resistant materials, such as bearing steel or ceramic materials, to ensure durability.

[0036] Specifically, the second washer 25 has a countersunk hole 251, and the shift sleeve assembly 2 also includes a second countersunk bolt 26 inserted into the countersunk hole 251, and a second self-locking nut 27. The second countersunk bolt 26 passes through the second washer 25 and the shift sleeve body 21 and is connected to the second self-locking nut 27. The above structure achieves a fixed connection between the second washer 25 and the shift sleeve body 21. The assembly structure is simple and facilitates the replacement of various components in case of damage.

[0037] Reference Figure 6 and Figure 7As shown, the slider assembly 4 includes a slider body 41 and a plurality of balls 42. The upper and lower surfaces of the slider body 41 are provided with a plurality of elongated grooves 411, and the balls 42 are disposed in the elongated grooves 411, abutting against the surfaces of the first pad 22 and the second pad 25. The balls 42 transform the sliding friction generated by the surface contact between the upper and lower surfaces of the slider body 41 and the first pad 22 and the second pad 25 into rolling friction between the balls 42 and the first pad 22 and the second pad 25, thereby improving the service life of the slider body 41, the first pad 22, and the second pad 25, and reducing maintenance costs.

[0038] Preferably, the slider body 41 has two spaced-apart elongated grooves 411 on the same side surface to ensure that the slider body 41 maintains its balance during movement. Of course, there can also be multiple elongated grooves 411 on the same side surface.

[0039] The long groove 411 penetrates the slider body 41 and forms an opening. The ball 42 is inserted into the long groove 411 through the opening. The slider assembly 4 also includes a baffle 43 for sealing the opening. The baffle 43 is fixedly connected to the slider body 41.

[0040] The slider assembly 4 also includes a first countersunk bolt 44, which passes through the baffle 43 and is connected to the slider body 41. The slider body 41 and the baffle 43 are fixedly connected through the above structure, and the assembly structure is simple.

[0041] Specifically, while the ball bearing 42 protrudes from the upper and lower surfaces of the slider body 41, the slider body 41 has a threaded hole 412 on the side with the long groove 411. After all the long grooves 411 are filled with the same number of ball bearings 42, the baffle 43 is covered and fixed to the baffle 43 by the first countersunk bolt 44 engaging with the threaded hole 412 on the side of the slider body 41, ensuring that the ball bearing 42 will not fall out.

[0042] The ball bearings 42 can be made of high-hardness, high-wear-resistant materials, such as bearing steel or ceramic materials, to ensure durability.

[0043] The eccentric pin 31 is connected to the slider assembly 4 by a flat-head bolt 7 or a flexible retaining ring. The eccentric pin 31 passes through the end of the slider body 41, and a flat-head bolt 7 or a flexible retaining ring is connected at this end. The flat-head bolt 7 or the flexible retaining ring is used to prevent the eccentric pin 31 from disengaging from the slider body 41, so as to ensure the fixed connection between the propeller shaft 3 and the slider assembly 4.

[0044] On the other hand, this utility model provides an aircraft including the aforementioned aircraft propeller pitch-changing mechanism. Through the zero-clearance fit between the slider assembly 4 and the slide groove 28 provided by this utility model, all blades are ensured to be at the same pitch angle, preventing blade wobbling during rotation and thus affecting the stability and safety of the propeller operation. Simultaneously, the assembly structure is simple, greatly reducing the processing difficulty and improving assembly convenience, while ensuring the stability and safety of the propeller during operation.

[0045] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0046] In the description of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0047] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A variable pitch mechanism for an aircraft propeller, characterized in that: The device includes a propeller hub (1), inside which is a movable paddle assembly (2), and several propeller shafts (3) arranged in a circumferential array around the paddle assembly (2). The ends of the propeller shafts (3) are provided with eccentric pins (31), and the eccentric pins (31) are fixedly connected to slider assemblies (4). The paddle assembly (2) is provided with a groove (28) for the slider assembly (4) to move horizontally. The groove (28) includes two spaced end faces, which can be raised and lowered to adjust the width of the groove (28) so that the groove (28) is adapted to the height of the slider assembly (4).

2. The aircraft propeller pitch-changing mechanism according to claim 1, characterized in that: The shift sleeve assembly (2) includes a shift sleeve body (21), a first washer (22), a screw (23), and a first self-locking nut (24). The shift sleeve body (21) is provided with a mounting groove (211). The first washer (22) is disposed in the mounting groove (211). The screw (23) passes through the shift sleeve body (21) and abuts against the first washer (22). The first self-locking nut (24) is sleeved on the screw (23) and abuts against the shift sleeve body (21). The surface of the first washer (22) that abuts against the slider assembly (4) constitutes one of the end faces.

3. The aircraft propeller pitch-changing mechanism according to claim 2, characterized in that: The lever assembly (2) further includes a second gasket (25), which is fixed in the mounting groove (211). The second gasket (25) is detachably connected to the lever body (21), and the surface of the second gasket (25) that abuts against the slider assembly (4) constitutes one of the end faces.

4. The aircraft propeller pitch-changing mechanism according to claim 2, characterized in that: The dial sleeve body (21) is provided with a plurality of blind holes (212), and the first gasket (22) is provided with a positioning pin (221) that is embedded in the blind holes (212).

5. The aircraft propeller pitch-changing mechanism according to claim 3, characterized in that: The second washer (25) is provided with a countersunk hole (251), and the shift sleeve assembly (2) further includes a second countersunk bolt (26) inserted into the countersunk hole (251) and a second self-locking nut (27). The second countersunk bolt (26) passes through the second washer (25) and the shift sleeve body (21) and is connected to the second self-locking nut (27).

6. An aircraft propeller pitch-changing mechanism according to any one of claims 1 to 5, characterized in that: The slider assembly (4) includes a slider body (41) and a plurality of balls (42). The upper and lower surfaces of the slider body (41) are provided with a plurality of long grooves (411). The balls (42) are disposed in the long grooves (411) and abut against the end face.

7. The aircraft propeller pitch-changing mechanism according to claim 6, characterized in that: The long groove (411) penetrates the slider body (41) and forms an opening. The ball (42) is inserted into the long groove (411) through the opening. The slider assembly (4) also includes a baffle (43) for sealing the opening. The baffle (43) is fixedly connected to the slider body (41).

8. The aircraft propeller pitch-changing mechanism according to claim 7, characterized in that: The slider assembly (4) further includes a first countersunk bolt (44), which passes through the baffle (43) and is connected to the slider body (41).

9. An aircraft propeller pitch-changing mechanism according to any one of claims 1 to 5, characterized in that: The eccentric pin (31) is connected to the slider assembly (4) by a flat-head bolt (7) or an elastic retaining ring.

10. An aircraft, characterized in that: Including an aircraft propeller pitch control mechanism as described in any one of claims 1 to 9.

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