Gear pitch changing mechanism suitable for double-blade propeller

Abstract

The gear pitch changing mechanism comprises a propeller hub, a propeller blade assembly is arranged on the propeller hub, a pitch changing assembly is arranged in the propeller hub, and the propeller blade assembly comprises propeller blades, a propeller blade clamp, a pitch changing shaft, a tapered roller bearing, a sleeve, a propeller blade bolt, a screw, a bearing end cover and a sealing ring. The variable pitch assembly comprises a flat key, a driven bevel gear, a center screw, a shaft end check ring, a driving bevel gear, a bolt spherical shell, a deep groove ball bearing, a shaft sleeve, a short shaft, a metal rod piece and a steering engine, and large-range variable pitch can be achieved through multi-stage rotation transmission among the driving bevel gear, the driven bevel gear, the variable pitch shaft, the paddle clamps and the paddles.

Description

Technical Field

[0001] The utility model relates to the technical field of gear pitch change, in particular to a gear pitch change mechanism suitable for a double-blade propeller. Background Art

[0002] For two-blade propellers, they are mainly used on light helicopters, and most of them adopt the articulated variable pitch method. The main disadvantages include the following points:

[0003] Large gap in connecting rod installation: Most connecting rods are ball-jointed, which results in a large gap between connecting rods, making it difficult to accurately change the pitch.

[0004] High maintenance cost: Due to its complex mechanical structure, maintenance and repair are usually more expensive and difficult.

[0005] Reliability issues: The complexity of the connecting rod pitch change mechanism increases potential failure points and may cause reliability problems during flight. Utility Model Content

[0006] The utility model aims to solve the technical problems existing in the prior art and provide a gear pitch changing mechanism suitable for a double-blade propeller.

[0007] To achieve the above-mentioned purpose, the technical solution provided by the utility model is: a gear pitch-changing mechanism suitable for a double-blade propeller, comprising a propeller hub, a propeller blade assembly is arranged on the propeller hub, and a pitch-changing assembly is arranged inside the propeller hub;

[0008] The propeller hub includes a propeller hub shell, a main shaft, and a spherical shell bolt. The propeller hub is composed of a left and a right hemispherical shell. The two hemispherical shells are connected by spherical shell bolts. The main shaft is a hollow part and is installed on the propeller hub shell by bolts.

[0009] The blade assembly includes blades, blade clamps, pitch shafts, tapered roller bearings, sleeves, blade bolts, screws, bearing end covers, and sealing rings;

[0010] The root of the blade is in a cubic shape, and a threaded hole is provided at the root of the blade. The blade is connected to the right side of the blade clamp through a blade bolt; the left side of the blade clamp is cylindrical, and the cylindrical part of the left side of the blade clamp is provided with an assembly hole, and the pitch-changing shaft is installed in the assembly hole through bolts; a pair of tapered roller bearings are installed on the pitch-changing shaft, and the inner side of the tapered roller bearing is positioned by a sleeve and a shoulder, and the outer side bearing of the tapered roller bearing is positioned by a shoulder and a bearing end cover, and the bearing end cover is installed on the hub shell through screws;

[0011] The pitch changing assembly includes a flat key, a driven bevel gear, a center screw, a shaft end retaining ring, a driving bevel gear, a bolt ball shell, a deep groove ball bearing, a shaft sleeve, and a short shaft;

[0012] The driven bevel gear is installed on the pitch-changing shaft. The shaft end of the driven bevel gear is fixed and axially positioned by the bearing retaining ring and the center screw. The driven bevel gear completes the circumferential positioning and transmits the torque with the pitch-changing shaft through the flat key.

[0013] The driving bevel gear is installed on the short shaft, the shaft end of the driving bevel gear is fixed and axially positioned by the bearing retaining ring, the circumferential positioning of the driving bevel gear is completed by a flat key, and the driving bevel gear is meshed with the driven bevel gear; the deep groove ball bearing is installed on the short shaft, and the sleeve is installed on the short shaft to separate the driving bevel gear and the deep groove ball bearing, and to axially position the deep groove ball bearing.

[0014] Preferably, a sealing ring is provided on the bearing end cover.

[0015] Preferably, the pitch change assembly also includes a metal rod and a servo, the servo is mounted on the inner bottom of the hub shell, one end of the metal rod is mounted on the servo, and the other end of the metal rod is mounted on the active bevel gear for transmitting the torque of the servo.

[0016] Preferably, a through hole is drilled on the vertical surface of the active bevel gear to facilitate connection with the steering gear using a metal rod.

[0017] Preferably, the sleeve is mounted on the stub shaft and is simultaneously mounted and positioned on the hub shell by means of hexagon socket bolts.

[0018] Preferably, the cylindrical surface on the left side of the blade clamp is milled flat to facilitate installation and tightening of bolts and nuts.

[0019] Beneficial effects of the utility model:

[0020] In the utility model, the blade is connected to the hub through a blade clamp, the blade assembly is connected to the pitch variable assembly through a pitch variable shaft, the pitch variable assembly is installed on the hub, the rotation of the steering gear will drive the active bevel gear to rotate, the active bevel gear and the driven bevel gear are meshed with each other, the active bevel gear transmits the rotation transmitted by the steering gear to the driven bevel gear and changes the rotation plane, so that the rotation plane is changed to the same rotation plane as the blade pitch change, the driven bevel gear and the pitch variable shaft are connected through a flat key, driving the pitch variable shaft to rotate, the pitch variable shaft is connected to the blade clamp through a bolt, thereby transmitting the rotation to the blade clamp, the blade clamp and the blade are connected through the blade bolt, the rotation is transmitted to the blade, thereby realizing the pitch change movement of the blade, and the meshing of the active bevel gear and the driven bevel gear can ensure the pitch change accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0022] Figure 1It is a half-section view of the main view of the utility model;

[0023] Figure 2 It is a side view cross-sectional view of the utility model;

[0024] Figure 3 It is an isometric cross-sectional view of the utility model;

[0025] Figure 4 This is a steering gear connection diagram of the utility model;

[0026] Figure 5 It is the front view of the utility model;

[0027] Figure 6 It is a top view of the utility model;

[0028] Figure 7 It is the front view isometric drawing of the model of the utility model;

[0029] Figure 8 It is the rear view isometric drawing of the model of the utility model;

[0030] Fig. 9 It is the front view of the utility model model;

[0031] Fig.10 It is a side view of the utility model model;

[0032] Fig.11 It is a top view of the model of the utility model;

[0033] Fig.12 It is a rear view of the utility model model;

[0034] Fig.13 It is a bottom view of the model of the utility model;

[0035] Fig.14 It is a front view internal structure diagram of the utility model model;

[0036] Fig.15 It is the rear view internal structure diagram of the utility model model;

[0037] Fig.16 It is a cross-sectional view of the internal structure of the model of the utility model.

[0038] Figure annotation:

[0039] 1-blade, 2-blade clamp, 3-blade bolt, 4-pitch shaft, 5-tapered roller bearing, 6-sleeve, 7-bearing end cover, 8-hub housing, 9-screw, 10-hexagon socket bolt, 11-sealing ring, 12-flat key, 13-driven bevel gear, 14-center screw, 15-shaft end retaining ring, 16-driving bevel gear, 17-ball shell bolt, 18-deep groove ball bearing, 19-sleeve, 20-short shaft, 21-metal rod, 22-servo, 23-spindle. DETAILED DESCRIPTION

[0040] This section will describe in detail the specific embodiments of the utility model. The preferred embodiments of the utility model are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the utility model, but it cannot be understood as a limitation on the protection scope of the utility model.

[0041] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0042] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0043] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0044] The utility model provides a gear pitch changing mechanism suitable for a double-blade propeller, wherein the advantages of the gear pitch changing mechanism include:

[0045] 1. Precise pitch change: The gear installation gap is very small, which can achieve precise pitch change;

[0046] 2. Strong safety: The gear has strong load-bearing capacity, which is beneficial to improving the operating stability of the propeller;

[0047] 3. Easy maintenance: The gears are installed inside the hub, which is easy to lubricate, has little contact with the outside world, and is not prone to corrosion and other damage.

[0048] Example 1

[0049] Reference Figure 1-Figure 16 The preferred embodiment of the utility model is a gear pitch-changing mechanism suitable for a double-blade propeller, comprising a hub, a blade assembly is arranged on the hub, and a pitch-changing assembly is arranged inside the hub; the whole device is axially symmetrically distributed.

[0050] The propeller hub includes a propeller hub shell 8, a main shaft 23, and a ball shell bolt 17. The propeller hub is composed of a left and a right hemispherical shell. The two hemispherical shells are connected by the ball shell bolt 17. The main shaft 23 is used to transmit the engine torque to drive the entire device to rotate. The main shaft 23 is a hollow part, which is convenient for the steering gear 22 to lead outward. The main shaft 22 is installed on the propeller hub shell 8 by bolts;

[0051] Since the device is small in size and the center of gravity of the hub shell 8 is far from the rotation center of gravity, the circumferential force it bears is not large, and the hovering pull of the helicopter is much greater than the centrifugal force. In addition, the main shaft 23 is connected to the hub, which further enhances the centrifugal stability. Therefore, the hub is installed to rotate left and right.

[0052] The advantage of installing the hub left and right is that at the installation point of the blade 1 and the hub shell 8, the hub shell 8 is an integral structure, and is not separated as when the hub shell 8 is installed up and down. It has a supporting effect on the stability of the blade assembly, and eliminating the blade root fastening ring, cone ring and other parts can also ensure that the blade assembly is firmly installed.

[0053] The blade assembly includes a blade 1, a blade clamp 2, a pitch shaft 4, a tapered roller bearing 5, a sleeve 6, a blade bolt 3, a screw 9, a bearing end cover 7, and a sealing ring 11; the root of the blade 1 is in a cubic shape, and a threaded hole is provided at the root of the blade 1. The blade 1 is connected to the right side of the blade clamp 2 through the blade bolt 3; the left side of the blade clamp 2 is cylindrical, and the cylindrical part on the left side of the blade clamp 2 is provided with an assembly hole, and the pitch shaft 4 is installed in the assembly hole through bolts; a pair of tapered roller bearings 5 ​​are installed on the pitch shaft 4, which can transmit axial loads and support rotation. The inner side of the tapered roller bearing 5 is positioned by the sleeve 6 and the shaft shoulder, and the outer bearing of the tapered roller bearing 5 is positioned by the shaft shoulder and the bearing end cover 7, and the bearing end cover 7 is installed on the hub shell 8 through screws 9;

[0054] The pitch changing assembly includes a flat key 12, a driven bevel gear 13, a center screw 14, a shaft end retaining ring 15, a driving bevel gear 16, a deep groove ball bearing 18, a shaft sleeve 19, and a short shaft 20; the driven bevel gear 13 is installed on the pitch changing shaft 4, the shaft end of the driven bevel gear 13 is fixed and axially positioned by the bearing retaining ring 15 and the center screw 14, and the driven bevel gear 13 completes circumferential positioning and transmits torque with the pitch changing shaft 4 through the flat key 12;

[0055] The driving bevel gear 16 is mounted on the short shaft 20, the shaft end of the driving bevel gear 16 is fixed and axially positioned by the bearing retaining ring 15, the circumferential positioning of the driving bevel gear 16 is completed by the flat key 12, and the driving bevel gear 16 is meshed with the driven bevel gear 13; the deep groove ball bearing 18 is mounted on the short shaft 20, which can withstand axial loads and reduce friction resistance, and the shaft sleeve 19 is mounted on the short shaft 20 to separate the driving bevel gear 16 and the deep groove ball bearing 18, and to axially position the deep groove ball bearing 18.

[0056] Furthermore, a sealing ring 11 is provided on the bearing end cover 7 to reduce the rotational friction between the pitch-changing shaft 4 and the bearing end cover 7 and prevent the intrusion of dust, moisture and other impurities from the outside.

[0057] The pitch-changing assembly further includes a metal rod 21 and a steering gear 22 . The steering gear 22 is mounted on the inner bottom of the hub housing 8 . One end of the metal rod 21 is mounted on the steering gear 22 , and the other end of the metal rod 21 is mounted on the active bevel gear 16 for transmitting the torque of the steering gear 22 .

[0058] A through hole is drilled on the vertical surface of the active bevel gear 16 to facilitate connection with the steering gear 22 using a metal rod 21 .

[0059] The shaft sleeve 19 is installed on the short shaft 20 and is installed and positioned on the hub shell 8 through the hexagon socket bolt 10, thereby fixing the blade assembly and increasing the installation reliability of the blade assembly.

[0060] The cylindrical surface on the left side of the blade clamp 2 is milled flat to facilitate the installation and tightening of bolts and nuts.

[0061] Working principle of the utility model: In the utility model, the blade 1 is connected to the hub through the blade clamp 2, the blade assembly is connected to the pitch assembly through the pitch shaft 4, the pitch assembly is installed on the hub, the steering gear 22 is connected to the active bevel gear 16 through the metal rod 21, the rotation of the steering gear 22 will drive the active bevel gear 16 to rotate, the active bevel gear 16 and the driven bevel gear 13 are meshed with each other, the active bevel gear 16 transmits the rotation transmitted by the steering gear 22 to the driven bevel gear 13 and changes the rotation plane, so that the rotation plane is changed to the same rotation plane as the pitch change of the blade 1, the driven bevel gear 13 is connected to the pitch shaft 4 through the flat key 12, driving the pitch shaft 4 to rotate, the pitch shaft 4 is connected to the blade clamp 2 through bolts, thereby transmitting the rotation to the blade clamp 2, the blade clamp 2 is connected to the blade 1 through the blade bolt 3, and the rotation is transmitted to the blade 1, thereby realizing the pitch change movement of the blade 1, and the meshing of the active bevel gear 16 and the driven bevel gear 13 can ensure the pitch change accuracy.

[0062] The utility model can realize a wide range of pitch change through multi-stage rotation transmission among the driving bevel gear 16, the driven bevel gear 13, the pitch change shaft 4, the blade clamp 2 and the blade 1.

[0063] Under the premise that no conflict occurs, those skilled in the art may freely combine and superimpose the above-mentioned additional technical features.

[0064] The above description is only a preferred implementation mode of the present utility model. Any technical solution that achieves the purpose of the present utility model by basically the same means belongs to the protection scope of the present utility model.

Claims

1. A gear pitch changing mechanism suitable for a twin-blade propeller, characterized in that: It includes a propeller hub, a propeller blade assembly is arranged on the propeller hub, and a pitch-changing assembly is arranged inside the propeller hub; The propeller hub includes a propeller hub shell, a main shaft, and a spherical shell bolt. The propeller hub is composed of a left and a right hemispherical shell. The two hemispherical shells are connected by spherical shell bolts. The main shaft is a hollow part and is installed on the propeller hub shell by bolts. The blade assembly includes a blade, a blade clamp, a pitch-changing shaft, a tapered roller bearing, a sleeve, a blade bolt, a screw, a bearing end cover, and a sealing ring; the root of the blade is in a cubic shape, and a threaded hole is provided at the root of the blade. The blade is connected to the right side of the blade clamp through a blade bolt; the left side of the blade clamp is cylindrical, and the cylindrical part of the left side of the blade clamp is provided with an assembly hole, and the pitch-changing shaft is installed in the assembly hole through bolts; a pair of tapered roller bearings are installed on the pitch-changing shaft, and the inner side of the tapered roller bearing is positioned by a sleeve and a shaft shoulder, and the outer side bearing of the tapered roller bearing is positioned by a shaft shoulder and a bearing end cover, and the bearing end cover is installed on the hub shell through screws; The pitch-changing assembly includes a flat key, a driven bevel gear, a center screw, a shaft end retaining ring, a driving bevel gear, a bolt ball shell, a deep groove ball bearing, a shaft sleeve, and a short shaft; the driven bevel gear is installed on the pitch-changing shaft, and the shaft end of the driven bevel gear is fixed and axially positioned by the bearing retaining ring and the center screw. The driven bevel gear completes circumferential positioning and transmits torque with the pitch-changing shaft through the flat key; The driving bevel gear is installed on the short shaft, the shaft end of the driving bevel gear is fixed and axially positioned by the bearing retaining ring, the circumferential positioning of the driving bevel gear is completed by a flat key, and the driving bevel gear is meshed with the driven bevel gear; the deep groove ball bearing is installed on the short shaft, and the sleeve is installed on the short shaft to separate the driving bevel gear and the deep groove ball bearing, and to axially position the deep groove ball bearing.

2. A gear pitch changing mechanism suitable for a twin-blade propeller according to claim 1, characterized in that: A sealing ring is arranged on the bearing end cover.

3. The gear pitch changing mechanism suitable for a twin-blade propeller according to claim 1, characterized in that: The variable pitch assembly also includes a metal rod and a servo. The servo is installed at the inner bottom of the hub shell. One end of the metal rod is installed on the servo, and the other end of the metal rod is installed on the active bevel gear for transmitting the torque of the servo.

4. The gear pitch changing mechanism suitable for a twin-blade propeller according to claim 3, characterized in that: A through hole is drilled on the vertical surface of the active bevel gear to facilitate connection with the steering gear using a metal rod.

5. The gear pitch changing mechanism suitable for a twin-blade propeller according to claim 1, characterized in that: The sleeve is installed on the short shaft and is installed and positioned on the hub shell by means of hexagon socket bolts.

6. The gear pitch changing mechanism suitable for a twin-blade propeller according to claim 1, characterized in that: The cylindrical surface on the left side of the blade clamp is milled flat to facilitate the installation and tightening of bolts and nuts.

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