Speed reducer and aircraft

Abstract

The utility model provides a speed reducer which comprises an output shaft, an output gear and an overload protector. The overload protector comprises a shell which is arranged on the output shaft in a sleeving mode, the shell is in tooth connection with the output shaft through a spline, and an annular containing cavity is further formed in the shell; the multiple outer friction plates are arranged in the containing cavity at intervals in the axial direction of the output shaft and fixedly connected with the shell. Each inner friction plate is arranged between two adjacent outer friction plates, and the inner friction plates are in toothed connection with the output gear through splines; the elastic piece is suitable for applying pressure for extruding the inner friction plates to the outer friction plates on the outermost side, so that the outer friction plates and the inner friction plates are in a mutual pressing state, and the torque of the output gear is transmitted to the output shaft; the multiple outer friction plates and the multiple inner friction plates further respond to the situation that the output bearing is subjected to torsion larger than the preset torque, so that the multiple outer friction plates and the multiple inner friction plates are in a mutual slipping state, and torque transmission between the output gear and the output shaft is cut off.

Description

Technical Field

[0001] The utility model relates to the field of mechanical engineering, in particular to a speed reducer and an aircraft. Background Art

[0002] During the flight of an aircraft, the reducer may be overloaded due to sudden acceleration or deceleration of the propeller, or accidental contact with foreign objects. This may cause the internal components of the reducer to break or be damaged, resulting in damage to the aircraft's power system, increased maintenance costs and flight risks, which makes the overload protection function in the reducer particularly important.

[0003] Currently, overload protection in reducers is achieved by using a shaft lock pin. For example, Chinese utility model patent publication number CN209212837U discloses a reducer with overload protection. This uses a lock pin to secure the motor shaft. When the speed is too high, the lock pin pops out, cutting off the power transmission between the motor and the reducer, thus achieving overload protection. This method has drawbacks. Since the lock pin pops out when overload occurs, it is uncontrollable and may damage other components or endanger personal safety. In addition, it requires a large installation space and is heavy, which does not meet the requirements of lightweight design. Utility Model Content

[0004] In view of this, the present invention provides a speed reducer and an aircraft.

[0005] One aspect of the present invention provides a speed reducer comprising an output shaft, an output gear, and an overload protector; the output gear is sleeved on the output shaft; the overload protector comprises a housing, a plurality of outer friction plates, a plurality of inner friction plates, and an elastic member. The housing is sleeved on the output shaft and is splined to the output shaft. The housing further defines an annular accommodating cavity; the plurality of outer friction plates are spaced apart in the accommodating cavity along the axial direction of the output shaft and fixedly connected to the housing; each inner friction plate is disposed between two adjacent outer friction plates and splined to the output gear; the elastic member is adapted to apply pressure to the outermost outer friction plate to compress the inner friction plates, causing the plurality of outer friction plates and the plurality of inner friction plates to be in a mutually compressed state, thereby transmitting the torque of the output gear to the output shaft; wherein, in response to a torque greater than a preset torque being applied to the output bearing, the plurality of outer friction plates and the plurality of inner friction plates are caused to slip relative to each other, thereby cutting off the torque transmission between the output gear and the output shaft.

[0006] According to an embodiment of the present disclosure, the shell includes an inner shell and an outer shell, the inner shell includes a connecting portion and a shoulder, the connecting portion is provided with an internal spline and is sleeved on the outer side of the output shaft; the shoulder is formed on the outer wall of the connecting portion and extends along the radial direction of the output shaft; the space between the outer shell and the inner shell forms an accommodating cavity, wherein the first end of the outer shell is fixedly connected to the shoulder.

[0007] According to an embodiment of the present disclosure, the overload protector further includes a pressing portion, which is arranged between the second end of the outer shell away from the first end and the facing outer friction plates, and abuts against the outer friction plates.

[0008] According to an embodiment of the present disclosure, the overload protector also includes a cover body, which is arranged on the second end of the outer shell and the pressing part, and forms a limiting groove for accommodating the elastic member with the outer shell and the pressing part; one end of the elastic member abuts on the cover body, and the other end of the elastic member abuts on the pressing part.

[0009] According to an embodiment of the present disclosure, the elastic member includes a disc spring.

[0010] According to an embodiment of the present disclosure, a gap is provided between the inner housing and the inner friction plate along the radial direction of the inner housing to accommodate the output gear extending from the second end of the outer housing into the accommodating cavity; the inner friction plate is provided with an internal spline to enable the output gear to be meshed with the inner friction plate.

[0011] According to an embodiment of the present disclosure, it also includes a snap ring seat, which is installed at one end of the output shaft close to the output gear; and a snap ring, which is installed in a preset groove of the output shaft and is cooperatively connected with the snap ring seat.

[0012] According to an embodiment of the present disclosure, it also includes: a flange, which is arranged at one end of the output shaft away from the output gear and is fixedly connected to the output gear to output torque to the outside; a butterfly spring seat, which is arranged between the flange and the overload protector and is sleeved on the output shaft; a butterfly spring, which is sleeved on the output shaft, with one end of the butterfly spring abutting against the shoulder and the other end of the butterfly spring abutting against the butterfly spring seat.

[0013] According to an embodiment of the present disclosure, a gap is provided between the output shaft and the output gear along the radial direction of the output shaft.

[0014] Another aspect of the present invention provides an aircraft equipped with the above-mentioned speed reducer.

[0015] The reducer provided herein employs an overload protector disposed on the output shaft. An inner friction plate is engaged with the output gear, an outer friction plate is fixedly connected to the housing, and the housing is engaged with the output shaft. An elastic member compresses the inner and outer friction plates. When the output gear rotates, the friction torque of the inner and outer friction plates drives the overload protector, which in turn drives the output shaft, thereby transmitting torque. When the output shaft is subjected to a torque greater than a preset torque, the friction torque is overcome, causing the outer and inner friction plates to slip relative to each other, thereby interrupting torque transmission between the output gear and the output shaft, effectively preventing damage to the equipment due to overload. Furthermore, the overload protector is disposed between the output shaft and the output gear, making the overall structure compact and improving space utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0017] Figure 1 A cross-sectional view of a reducer according to an embodiment of the present invention is schematically shown;

[0018] Figure 2 The cross-sectional view of the overload protector according to the embodiment of the present utility model is schematically shown.

[0019] Reference numerals

[0020] 1. Output shaft;

[0021] 2. Output gear;

[0022] 3. Overload protector;

[0023] 31. Outer shell;

[0024] 32. Inner shell;

[0025] 321, connecting part;

[0026] 322, shoulder;

[0027] 33. External friction plate;

[0028] 34. Internal friction plate;

[0029] 35. Elastic parts;

[0030] 36. Pressing part;

[0031] 37. Cover;

[0032] 4. Snap ring;

[0033] 5. Snap ring seat;

[0034] 6.Butterfly spring;

[0035] 7. Butterfly spring seat;

[0036] 8. Input shaft;

[0037] 9. Input gear;

[0038] 10. Intermediate gear shaft;

[0039] 11. Flange;

[0040] 12. Nut;

[0041] 13. Vent cap;

[0042] 14. Oil blockage. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0044] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the presence of features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0045] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0046] When expressions such as “at least one of A, B, and C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art. For example, “a system having at least one of A, B, and C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc. When expressions such as “at least one of A, B, or C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art. For example, “a system having at least one of A, B, or C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.

[0047] It should also be noted that directional terms such as "upper," "lower," "front," "back," "left," and "right" mentioned in the embodiments are merely references to the drawings and are not intended to limit the scope of protection of the present invention. Throughout the drawings, identical elements are represented by identical or similar reference numerals. Conventional structures or configurations will be omitted where they may cause confusion in understanding the present invention.

[0048] Figure 1 The cross-sectional view of the reducer according to the embodiment of the present utility model is schematically shown.

[0049] According to a reducer provided by the utility model, Figure 1 As shown, it includes an output shaft 1, an output gear 2 and an overload protector 3. The output gear 2 is sleeved on the output shaft 1. The overload protector 3 includes a housing, a plurality of outer friction plates 33, a plurality of inner friction plates 34 and an elastic member 35. The housing is sleeved on the output shaft 1, and the housing is splined to the output shaft 1. The housing also forms an annular accommodating cavity. The plurality of outer friction plates 33 are arranged in the accommodating cavity at intervals along the axial direction of the output shaft 1 and are fixedly connected to the housing. Each inner friction plate 34 is arranged between two adjacent outer friction plates 33, and the inner friction plates 34 are splined to the output gear 2. The elastic member 35 is suitable for applying pressure to the outermost outer friction plate 33 to squeeze the inner friction plate 34, so that the plurality of outer friction plates 33 and the plurality of inner friction plates 34 are in a mutually compressed state to transmit the torque of the output gear 2 to the output shaft 1. In response to the output shaft 1 being subjected to a torque greater than a preset torque, the multiple outer friction plates 33 and the multiple inner friction plates 34 are in a slipping state with each other, thereby cutting off the torque transmission between the output gear 2 and the output shaft 1.

[0050] In this embodiment, an overload protector 3 is installed on the output shaft 1. The inner friction plates 34 are gear-engaged with the output gear 2, while the outer friction plates 33 are fixedly connected to the housing. The housing is gear-engaged with the output shaft 1. An elastic member 35 maintains a tight compression between the inner and outer friction plates 34, 33. When the output gear 2 rotates, the friction torque between the inner and outer friction plates 34, 33 drives the overload protector 3, which in turn drives the output shaft 1, ensuring proper torque transmission. When the output shaft 1 is subjected to a torque greater than a preset torque, the friction torque is overcome, causing the outer and inner friction plates 33, 34 to slip against each other. This interrupts torque transmission between the output gear 2 and the output shaft 1, effectively preventing equipment damage caused by overload. Furthermore, the overload protector 3 is integrated between the output shaft 1 and the output gear 2, making the overall structure more compact and improving space utilization.

[0051] In an illustrative embodiment, Figure 1As shown, the reducer further includes a reducer housing, a sealed cavity is defined in the reducer housing, and the sealed cavity has a power input side and a power output side.

[0052] An input shaft 8 is mounted on the power input side of the sealed chamber, and the input shaft 8 can be supported by input bearings on both sides of the input shaft 8. An input gear 9 is meshedly connected to the input shaft 8, and the input shaft 8 can be connected to an external engine to receive the torque transmitted by the engine. An output shaft 1 can be mounted on the power output side, and the output shaft 1 can be supported by output bearings on both sides of the output shaft 1. An intermediate gear shaft 10 can also be provided between the input shaft 8 and the output shaft 1, and the intermediate gear shaft 10 can be supported by intermediate bearings on both sides of the intermediate gear shaft 10. The intermediate gear shaft 10 is meshedly connected to the input gear 9 and the output gear 2, respectively, thereby transmitting the torque from the input shaft 8 to the output gear 2.

[0053] In an illustrative embodiment, oil seals may be provided on both the power input side and the power output side of the reducer to ensure the sealing of the reducer during operation and prevent oil leakage.

[0054] According to the embodiments of the present disclosure, Figure 1 As shown, the reducer further includes a snap ring seat 5 and a snap ring 4. The snap ring seat 5 is mounted on one end of the output shaft 1 close to the output gear 2. The snap ring 4 is mounted in a groove preset in the output shaft 1 and is mated with the snap ring seat 5.

[0055] In this embodiment, the connection between the output shaft 1 and the output gear 2 is stabilized by the mating connection between the snap ring 4 and the snap ring seat 5. The snap ring 4 can effectively prevent the output gear 2 from falling off or loosening from the output shaft 1 when transmitting high torque or being subjected to impact loads.

[0056] According to the embodiments of the present disclosure, Figure 1 As shown, the reducer also includes a flange 11, a butterfly spring seat 7, and a butterfly spring 6. The flange 11 is disposed at the end of the output shaft 1 away from the output gear 2 and is fixedly connected to the output gear 2 to output torque externally. The butterfly spring seat 7 is disposed between the flange 11 and the overload protector 3 and is sleeved onto the output shaft 1. The butterfly spring is sleeved onto the output shaft 1, with one end of the butterfly spring abutting the shoulder 322 of the overload protector 3, and the other end of the butterfly spring 6 abutting the butterfly spring seat 7.

[0057] In such an embodiment, the butterfly spring 6 is squeezed by the butterfly spring seat 7 and the overload protector 3, thereby providing a preload force along the axial direction of the output shaft 1, and transmitting the preload force to the output gear 2 and the retaining ring 4, thereby achieving axial positioning of various components on the output shaft 1.

[0058] In an illustrative embodiment, Figure 1As shown, a nut 12 is provided between the rear end of the output shaft 1 and the flange 11 for locking the various components on the output shaft 1 .

[0059] In an illustrative embodiment, a vent cap 13 may be provided on the upper portion of the reducer housing for balancing the air pressure inside and outside the reducer and injecting lubricating oil; an oil plug 14 may be provided on the lower portion of the reducer housing for draining the lubricating oil when replacing the lubricating oil.

[0060] In an exemplary embodiment, an observation window may be provided on the reducer housing for observing the amount of lubricating oil. The reducer lubrication method adopts splash lubrication, which relies on the intermediate gear shaft 10 to stir the oil and throw the lubricating oil into the bearings and meshing gear surfaces that need lubrication.

[0061] Figure 2 The cross-sectional view of the overload protector 3 according to the embodiment of the present utility model is schematically shown.

[0062] According to the embodiments of the present disclosure, Figure 2 As shown, the housing of the overload protector 3 includes an inner housing 32 and an outer housing 31. The inner housing 32 includes a connecting portion 321 and a shoulder 322. The connecting portion 321 is provided with an internal spline and is sleeved onto the outer side of the output shaft 1. The shoulder 322 is formed on the outer wall of the connecting portion 321 and extends in the radial direction of the output shaft 1. The space between the outer housing 31 and the inner housing 32 forms a receiving chamber, wherein the first end of the outer housing 31 is fixedly connected to the shoulder 322.

[0063] Specifically, such as Figure 2 As shown, the connecting portion 321 is configured as a cylindrical structure, sleeved onto the output shaft 1. The inner wall of the connecting portion 321 is provided with internal splines to mesh with the output shaft 1, driving the output shaft 1 to rotate via the connecting portion 321. A shoulder 322 is provided on the outer wall of one side of the connecting portion 321 and is connected to the outer housing 31. The shoulder 322 and the connecting portion 321 can be configured as an integral structure. The housing can rotate together with the output shaft 1.

[0064] According to the embodiments of the present disclosure, Figure 2 As shown, the overload protector 3 further includes a pressing portion 36 , which is disposed between the second end of the outer shell 31 away from the first end and the facing outer friction plate 33 , and abuts against the outer friction plate 33 .

[0065] Specifically, such as Figure 2 As shown, the pressing portion 36 includes a bottom plate and a side wall. The side wall is sleeved between the outer shell and the inner shell, and the bottom plate is pressed against the outer friction plate 33.

[0066] According to the embodiments of the present disclosure, Figure 2As shown, the overload protector 3 also includes a cover body 37, which is covered on the second end of the outer shell 31 and the pressing portion 36, and forms a limiting groove for accommodating the elastic member 35 with the outer shell 31 and the pressing portion 36; one end of the elastic member 35 abuts on the cover body 37, and the other end of the elastic member 35 abuts on the pressing portion 36.

[0067] Specifically, such as Figure 2 As shown, the covering portion can be engaged with the outer wall of the outer shell 31, so that the covering portion and the shell are stably connected. At the same time, the covering portion can squeeze the elastic member 35, so that the elastic member 35 squeezes the pressing portion 36 and the inner friction plate 34 and the outer friction plate 33, so that the inner friction plate 34 and the outer friction plate 33 are in a compressed state. Therefore, the rotation of the inner friction plate 34 can drive the outer friction plate 33, the shell and the output shaft 1 to rotate.

[0068] According to an embodiment of the present disclosure, the elastic member 35 may be a disc spring, but the present disclosure is not limited thereto, and the elastic member 35 may also be a coil spring, an annular spring, etc.

[0069] According to an embodiment of the present disclosure, a gap is provided between the inner housing 32 and the inner friction plate 34 along the radial direction of the inner housing 32 to accommodate the output gear 2 extending from the second end of the outer housing 31 into the accommodating cavity; the inner friction plate 34 is provided with an internal spline to enable the output gear 2 to be meshed with the inner friction plate 34.

[0070] In this embodiment, the inner friction plate 34 is held in place solely by the compression of the outer friction plate 33. When the reducer experiences a torque overload, the friction torque exerted by the disc spring pressure on the inner and outer friction plates 34, 33 is overcome, causing the inner and outer friction plates 34, 33 to slip against each other. At this point, the output gear 2 rotates solely with the inner friction plate 34, while the outer friction plate 33 and the housing continue to rotate with the output shaft 1. This effectively cuts off torque transmission between the output gear 2 and the output shaft 1, protecting other transmission components connected to the output shaft 1 from damage. When the overload is removed, the inner and outer friction plates 34, 33 stop slipping, and the reducer resumes torque transmission between the output gear 2 and the output shaft 1.

[0071] According to an embodiment of the present disclosure, a gap is provided between the output shaft 1 and the output gear 2 along the radial direction of the output shaft 1 .

[0072] In such an embodiment, due to the clearance fit between the output gear 2 and the output shaft 1 , the output shaft 1 and the output gear 2 can rotate relative to each other when overloaded, thereby avoiding excessive friction and wear.

[0073] Another aspect of the present invention provides an aircraft equipped with the above-mentioned speed reducer.

[0074] Specifically, the input shaft 8 of the reducer can be connected to the engine of the aircraft, and the output shaft 1 of the reducer can be connected to the propeller of the aircraft. When the propeller is overloaded, such as sudden acceleration or deceleration, or the propeller collides with other objects, the inner friction plate 34 and the outer friction plate 33 in the reducer slip, cutting off the power transmission to the propeller, thereby ensuring that the propeller will not be damaged.

[0075] The above describes embodiments of the present invention. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be used in combination to advantage. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A reducer, characterized in that: include: Output shaft (1); An output gear (2) sleeved on the output shaft (1); as well as Overload protector (3), comprising: A housing, sleeved on the output shaft (1), the housing being gear-connected to the output shaft (1) via a spline, and the housing also forming an annular accommodating cavity; A plurality of outer friction plates (33) are arranged in the accommodating cavity at intervals along the axial direction of the output shaft (1) and are fixedly connected to the housing; a plurality of inner friction plates (34), each inner friction plate (34) being arranged between two adjacent outer friction plates (33), and the inner friction plates (34) being gear-connected with the output gear (2) via splines; and an elastic member (35) adapted to apply pressure to the outermost outer friction plate (33) to squeeze the inner friction plate (34), so that the plurality of outer friction plates (33) and the plurality of inner friction plates (34) are in a mutually compressed state, thereby transmitting the torque of the output gear (2) to the output shaft (1); The plurality of outer friction plates (33) and the plurality of inner friction plates (34) are in a mutually slipping state in response to the output shaft (1) being subjected to a torque greater than a preset torque, so as to cut off the torque transmission between the output gear (2) and the output shaft (1).

2. The reducer according to claim 1, characterized in that The housing comprises: The inner shell (32) comprises: The connecting portion (321) is provided with an internal spline and is sleeved on the outside of the output shaft (1); a shoulder (322) formed on the outer wall of the connecting portion (321) and extending in the radial direction of the output shaft (1); The space between the outer shell (31) and the inner shell (32) forms the accommodating cavity, wherein the first end of the outer shell (31) is fixedly connected to the shoulder (322).

3. The reducer according to claim 2, characterized in that: The overload protector (3) further comprises: The pressing portion (36) is provided between the second end of the outer shell (31) away from the first end and the outer friction plate (33) facing each other, and abuts against the outer friction plate (33).

4. The reducer according to claim 3, characterized in that The overload protector (3) further comprises: a cover body (37) which is arranged on the second end of the outer shell (31) and the pressing portion (36), and forms a limiting groove for accommodating the elastic member (35) together with the outer shell (31) and the pressing portion (36); One end of the elastic member (35) abuts against the cover body (37), and the other end of the elastic member (35) abuts against the pressing portion (36).

5. The reducer according to claim 4, characterized in that: The elastic member (35) includes a disc spring.

6. The reducer according to claim 4, characterized in that A gap is provided between the inner housing (32) and the inner friction plate (34) along the radial direction of the inner housing (32) to accommodate the output gear (2) extending from the second end of the outer housing (31) into the accommodating cavity; The inner friction plate (34) is provided with an internal spline so that the output gear (2) is meshedly connected with the inner friction plate (34).

7. The reducer according to claim 2, characterized in that: Also includes: A snap ring seat (5) is mounted on one end of the output shaft (1) close to the output gear (2); as well as A snap ring (4) is installed in a preset groove of the output shaft (1) and is cooperatively connected with the snap ring seat (5).

8. The reducer according to claim 7, characterized in that: Also includes: A flange (11) is provided at an end of the output shaft (1) away from the output gear (2) and is fixedly connected to the output gear (2) to output torque to the outside; A butterfly spring seat (7) is provided between the flange (11) and the overload protector (3), and is sleeved on the output shaft (1); A butterfly spring (6) is sleeved on the output shaft (1), one end of the butterfly spring (6) abuts against the shoulder (322), and the other end of the butterfly spring (6) abuts against the butterfly spring seat (7).

9. The reducer according to claim 1, characterized in that: A gap is provided between the output shaft (1) and the output gear (2) along the radial direction of the output shaft (1).

10. An aircraft, characterized in that: include: The invention is provided with a reducer as described in any one of claims 1 to 9.

Images