Non-eccentric single multi-tooth differential double meshing planetary gear reducer with flexible cylindrical road wheels

Abstract

The application discloses a non-excentric single-multiple-tooth-difference double-meshing planetary wheel reducer with flexible cylindrical followers, and belongs to the technical field of reducers. The reducer is composed of a casing, a fixed internal gear, a movable internal gear, a planetary carrier assembly, a power shaft and an output shaft. The fixed internal gear is fixed in the casing, and the movable internal gear and the planetary carrier can rotate around the same center. The output shaft rotates around the center of the bearing of the casing and is concentric with the internal gear, and is fixed. A power shaft is installed on the other side of the casing, and one end of the power shaft extends into the center of the planetary carrier assembly. The planetary carrier assembly comprises left and right clamping plates, and a plurality of planetary columns are distributed between the left and right clamping plates. A planetary gear is sleeved on one or more of the planetary columns, and a follower is sleeved on the rest of the planetary columns. The application adopts the followers to replace the planetary gears, compensates the tooth gap by using the elastic deformation of the followers, realizes the transmission of the single-tooth-difference or few-tooth-difference planetary reduction structure, and avoids the complex design and processing of the traditional excentric structure and harmonic structure.

Description

Technical Field

[0001] This invention belongs to the field of speed reducer technology, specifically a non-eccentric single-multi-tooth differential double-meshing planetary gear reducer with a flexible cylindrical follower wheel. Background Technology

[0002] Planetary gear reducers are widely used in mechanical transmission due to their compact structure and large transmission ratio. Traditional planetary gear reducers mostly adopt an all-metal planetary gear structure. In single-tooth or multi-tooth differential (two-tooth or more) reducer transmissions, eccentric mechanisms and harmonic meshing reduction of the planetary internal gears are often required, resulting in complex structures, high assembly precision requirements, and susceptibility to metal fatigue, vibration, and noise during operation. Furthermore, conventional single-tooth or multi-tooth differential (two-tooth or more) reducers typically lack self-locking functionality, requiring additional braking devices, which increases equipment size and cost.

[0003] In existing technologies, single-tooth-difference or multi-tooth-difference (two-tooth-difference or more) reducers, such as harmonic reducers, experience frequent deformation of the flexure, making them prone to metal fatigue. They are also difficult to manufacture, have a relatively short service life compared to internal gears, and are difficult to self-lock through their own structure. Self-locking requires the addition of a braking device, especially in single-tooth-difference dual-meshing scenarios, where the eccentric design further limits the realization of self-locking performance. Therefore, based on these problems, a new gear structure concept of "replacing some planetary gears with flexible cylindrical follower gears" was proposed, realizing the invention of a non-eccentric single / multi-tooth-difference dual-meshing planetary gear reducer with flexible cylindrical follower gears. Summary of the Invention

[0004] In dual-meshing planetary gear reducers with single or multiple tooth differences, although self-locking capability is possible, the tooth difference is generally greater than or equal to 3. If the tooth difference is too small (e.g., 2), the planetary carrier structure will be asymmetrical, leading to uneven meshing forces between the planetary gears and the fixed internal gear. This, in turn, causes the planetary gears to wobble in the 90° direction along their axis, resulting in noise and vibration. Furthermore, because the tooth difference is 3, the reduction ratio constant of the reducer is... (1: If the tooth difference is equal to 1, the reduction ratio constant is... It is 3 times that of a reducer with a tooth difference of 3. Thus, for the same number of teeth and module, the reduction ratio constant will be several times larger. This is a reduction ratio constant that a harmonic reducer gearbox of the same volume cannot achieve (the harmonic reduction ratio constant is the number of teeth of the harmonic flexure / the tooth difference between the fixed gear and the flexure, with a minimum tooth difference of 2). In this way, the harmonic reducer can only mesh with one planetary gear. The force on the planetary gear and the fixed and moving internal gears is uneven and asymmetrical, which will produce noise and vibration problems.

[0005] Therefore, this invention aims to achieve a minimum tooth difference of 1 (or 2) and a number of planetary gears (including follower gears) of 3 or more, ensuring that the planetary gears and the fixed and moving internal gears are subjected to symmetrical and uniform forces. Such a double-meshing, low-tooth-difference (tooth difference of 1) reduction ratio constant will be very large, resulting in a simple, reliable, and long-lasting reducer structure.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a non-eccentric single- or multi-tooth differential double-meshing planetary gear reducer with a flexible cylindrical follower gear, comprising a housing, a fixed internal gear, a moving internal gear, a planetary carrier assembly, a drive shaft, and an output shaft; the planetary carrier assembly is disposed within the housing, one side of the housing is rotatably connected to the output shaft via a bearing, and the other side of the housing is fitted with the drive shaft, one end of which extends into and is connected to the planetary carrier assembly, and its end is rotatably connected to the output shaft via a bearing; the reducer is rotatably mounted within the housing on the side closest to the output shaft. The assembly includes a movable internal gear fixed to the output shaft, and a fixed internal gear fixed inside the housing near the power shaft. The planetary carrier assembly includes a left and right clamping plates arranged in parallel. The right clamping plate is rotatably connected to an end cover on the housing near the power shaft via a bearing. Multiple planetary gears are distributed between the left and right clamping plates, one or more of which are fitted with planetary gears, and the remaining planetary gears are fitted with follower gears. The planetary gears mesh with the inner sides of both the movable and fixed internal gears.

[0007] Furthermore, the follower wheel is configured as a flexible structure, and the follower wheel makes simultaneous rolling contact with the tip circles of the moving internal gear and the fixed internal gear.

[0008] Furthermore, the planetary gear meshes simultaneously with the fixed internal gear and the moving internal gear to form a double meshing transmission, and the tooth difference of the double meshing transmission is a single tooth difference or two or more tooth differences.

[0009] Furthermore, the power shaft is fixedly connected to the left and right clamping plates in the planetary carrier assembly by a key.

[0010] Furthermore, the power shaft is rotatably connected to the left clamping plate in the planetary carrier assembly, and a bearing three is assembled in the left clamping plate. The power shaft is fixed to the inner ring of the bearing three. A sun gear is machined or installed on the power shaft, and the planetary gear meshes externally with the sun gear.

[0011] Furthermore, the sun gear, planetary gears, fixed internal gears, and moving internal gears are all made of high-strength alloy steel.

[0012] Furthermore, the follower wheel includes a first flexible column and a second flexible column arranged at the same center, and the first flexible column and the second flexible column are fixed together by a bushing; the first flexible column is in rolling contact with the moving internal gear, and the second flexible column is in rolling contact with the fixed internal gear.

[0013] Furthermore, the addendum circles of the fixed internal gear and the moving internal gear are set to be equal or unequal circles; when the addendum circles of the two gears are equal circles, the flexible post one and flexible post two of the follower gear are of equal diameter and are adapted to mesh with the fixed internal gear and the moving internal gear; when the addendum circles of the two gears are unequal circles, the flexible post one and flexible post two of the follower gear are of two concentric elastic rims of unequal diameter and are adapted to mesh with the corresponding fixed internal gear and the moving internal gear respectively.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention uses rigid or elastic follower gears instead of traditional metal planetary gears, which can achieve dual meshing with the sun gear, fixed internal gear, and moving internal gear together with the planetary gears, and the transmission process does not require an eccentric mechanism; the tooth difference can be at least 1. When the tooth difference is 1 or 2, the follower gears need to be evenly or specifically distributed in the planetary carrier assembly to ensure uniform force distribution during the operation of the reducer, and at the same time, the reduction ratio constant can be greatly increased, which cannot be achieved by other reducers of the same volume; the structure of the present invention does not require eccentric or elliptical flexible gears, elliptical harmonic generator mechanisms, etc., simplifying the structure; the elastic meshing of the follower gears can also reduce vibration and noise to a certain extent and improve the smoothness of operation; and it is suitable for single tooth difference or multiple tooth difference (2 tooth difference or more) transmission, and is compatible with fixed internal gears and moving internal gears in scenarios of equal / unequal circles, with strong versatility. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure in this invention in which the power shaft and the left and right clamping plates of the planetary carrier are connected by a key to form a single unit;

[0016] Figure 2 This is a schematic diagram of the structure in this invention in which a sun gear is mounted on the power shaft and rotates to be connected to the left and right clamping plates of the planet carrier;

[0017] Figure 3 This is a schematic diagram of the overall structure of the present invention;

[0018] Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure of BB;

[0019] Figure 5 for Figure 3 A schematic diagram of the cross-sectional structure of AA.

[0020] Figure 6 This is a schematic diagram of the meshing transmission structure of the planetary gear, follower gear, sun gear, fixed internal gear, and moving internal gear in this invention;

[0021] Figure 7 This is a schematic diagram of the internal structure of the present invention;

[0022] Figure 8 This is a schematic diagram of the force-locking structure of the present invention;

[0023] In the diagram: 1. Housing; 11. Power shaft; 12. Output shaft; 13. Moving internal gear; 14. Stable internal gear; 15. Bearing 1; 2. Planetary carrier assembly; 21. Left clamping plate; 22. Right clamping plate; 23. Planetary column; 24. Planetary gear; 25. Sun gear; 3. Follower gear; 31. Flexible column 1; 32. Flexible column 2; 33. Bushing. Detailed Implementation

[0024] Please see Figures 1-8 In this embodiment of the invention, a non-eccentric single-multi-tooth differential double-meshing planetary gear reducer with a flexible cylindrical follower wheel includes a housing 1, a fixed internal gear 14, a moving internal gear 13, a planetary carrier assembly 2, a power shaft 11, and an output shaft 12. The planetary carrier assembly 2 is disposed inside the housing 1. The output shaft 12 is rotatably connected to one side of the housing 1 via a bearing 15, and the power shaft 11 is installed on the other side of the housing 1. One end of the power shaft 11 extends into and is connected to the planetary carrier assembly 2, and its end is rotatably connected to the output shaft 12 via a bearing 4.

[0025] A movable internal gear 13 is rotatably mounted inside the housing 1 near the output shaft 12. The movable internal gear 13 is fixed to the output shaft 12. A fixed internal gear 14 is fixed inside the housing 1 near the power shaft 11. The rotation direction of the power shaft 11 is the same as the rotation direction of the output shaft 12.

[0026] The planetary carrier assembly 2 includes a left clamping plate 21 and a right clamping plate 22 arranged in parallel. The right clamping plate 22 is rotatably connected to the end cover on the side of the housing 1 near the power shaft 11 via a bearing 2. The left clamping plate 21 and the output shaft 12 have an assembly gap, and multiple planetary columns 23 are distributed between the left clamping plate 21 and the right clamping plate 22. One or more of the planetary columns 23 are fitted with planetary gears 24, and the remaining planetary columns 23 are fitted with follower gears 3. The planetary gears 24 mesh with the inner sides of the moving internal gear 13 and the fixed internal gear 14. The elastic deformation of the follower gears 3 can compensate for the gap between the teeth. Single tooth difference (or few tooth difference) transmission can be realized without setting an eccentric mechanism, avoiding the complex design and processing of traditional eccentric structure and harmonic structure.

[0027] It should be noted that in single-to-multi-tooth differential transmissions, three or more planetary structures are used, with one or more planetary pinions 23 mounting planetary gears 24, and the rest mounting follower gears 3.

[0028] In this embodiment, the follower wheel 3 is configured as a flexible structure, and the follower wheel 3 rolls in contact with the tip circles of the moving internal gear 13 and the fixed internal gear 14 simultaneously without frictional sliding; and the outer circle of the follower wheel 3 is tangent to the tip circles of the moving internal gear 13 and the fixed internal gear 14.

[0029] In this device, the self-locking function of the reducer is achieved by setting a moving internal gear 13 and a fixed internal gear 14. When a torque T1 is applied to the output shaft 12 and transmitted to the moving internal gear 13 to the right, the moving internal gear 13 rotates to the right. The moving internal gear 13 transmits the applied torque to the meshing teeth of the planetary gears. This torque is then transmitted to the teeth of the fixed internal gear 14 through the gears of the planetary gear 24. Since the fixed internal gear 14 is fixed to the housing 1, it remains stationary. At this time, the moving internal gear 13, in conjunction with the fixed internal gear 14, clamps the planetary gear 24, preventing it from rotating on the fixed internal gear 14 and the planetary carrier. This achieves the self-locking function of the reducer, and vice versa. This self-locking function is reliable in strength, and the maximum load that the meshing teeth between the gears can withstand is the maximum self-locking force of the planetary reducer.

[0030] In a preferred embodiment, the planetary gear 24 meshes simultaneously with the fixed internal gear 14 and the moving internal gear 13 to form a double meshing transmission, wherein the tooth difference of the double meshing transmission is a single tooth difference or two or more tooth differences.

[0031] The minimum tooth difference of the reducer in this device can reach 1, so the reduction ratio is larger compared with reducers of the same size; and the power shaft 11 has two structures, which can be equipped with sun gear 25 or not, depending on the requirements.

[0032] In the first embodiment, the power shaft 11 is fixedly connected to the left clamping plate 21 and the right clamping plate 22 in the planetary carrier assembly 2 by a key. In this structure, the power shaft 11 does not need to be equipped with the sun gear 25.

[0033] Its reducer has a speed ratio constant. Calculation formula:

[0034] ;

[0035] For example: Sun Gear Planetary gears: Internal gear: Internal gear: ;

[0036] .

[0037] In the second embodiment, the power shaft 11 is rotatably connected to the left clamping plate 21 in the planetary carrier assembly 2, and the left clamping plate 21 is equipped with a bearing 3, and the power shaft 11 is fixed to the inner ring of the bearing 3.

[0038] A sun gear 25 is machined or installed on the power shaft 11. The planetary gear 24 meshes externally with the sun gear 25, while the planetary gear 24 meshes internally with the moving internal gear 13 and the fixed internal gear 14. It should be noted that the outer circle of the follower gear 3 is tangent to the tip circle of the moving internal gear 13 and the fixed internal gear 14, and is spaced from the tip circle of the sun gear 25 without interfering with it.

[0039] Its reducer has a speed ratio constant. Calculation formula:

[0040] .

[0041] For example: Sun Gear Planetary gears: Internal gear: Internal gear: ;

[0042] .

[0043] In summary, the two embodiments achieve a first-stage reduction ratio of 37 or 148, which are both quite large reduction ratio constants. Theoretically, as long as the base number of teeth of the moving internal gear 13 and the fixed internal gear 14 is large enough, the reduction ratio constant can be made even larger.

[0044] In this embodiment, the sun gear 25, planetary gear 24, fixed internal gear 14, and moving internal gear 13 are all made of high-strength alloy steel (such as 20CrMnTi) and are carburized and quenched to improve wear resistance.

[0045] In this embodiment, the follower wheel 3 includes a first flexible column 31 and a second flexible column 32 arranged at the same center. The first flexible column 31 and the second flexible column 32 are fixed together by a bushing 33, so that the bushing 33 can be assembled and fixed with the planetary column 23.

[0046] The first flexible column 31 rolls in contact with the moving internal gear 13, and the second flexible column 32 rolls in contact with the fixed internal gear 14. Both the first flexible column 31 and the second flexible column 32 are made of polyurethane elastomer material (or reinforced rubber, polytetrafluoroethylene, etc.), which has high elastic recovery and tear resistance, ensuring that it can produce moderate deformation and fatigue resistance during transmission.

[0047] The bushing 33 is made of rigid metal, which, together with the flexible column 1 31 and the flexible column 2 32, forms a composite structure of "hard core and soft surface", ensuring the overall support strength and positioning accuracy of the planetary carrier.

[0048] In this embodiment, the addendum circles of the fixed internal gear 14 and the moving internal gear 13 are set to be equal or unequal circles. When the addendum circles of the two are equal circles, the flexible column 31 and the flexible column 32 of the follower gear 3 are of equal diameter and are adapted to mesh with the fixed internal gear 14 and the moving internal gear 13. When the addendum circles of the two are unequal circles, the flexible column 31 and the flexible column 32 of the follower gear 3 are of two concentric elastic rims of unequal diameter and are adapted to mesh with the corresponding fixed internal gear 14 and the moving internal gear 13, respectively.

[0049] In the second embodiment of this device, during assembly, the sun gear 25 is fixed to the power shaft 11, and the planetary carrier assembly 2 is fitted onto the outside of the sun gear 25. Planetary gears 24 and follower gears 3 are assembled on the planetary column 23 of the planetary carrier assembly 2 according to design requirements, ensuring that the axes of planetary gears 24 and follower gears 3 are parallel to the axis of the sun gear 25. The fixed internal gear 14 (fixed to the housing 1) and the moving internal gear 13 (connected to the output shaft 12) are installed, so that the planetary gear 24 meshes with both the fixed internal gear 14 and the moving internal gear 13, and the follower gear 3 rolls in contact with both the fixed internal gear 14 and the moving internal gear 13, thus completing the assembly.

[0050] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A non-eccentric single- or multi-tooth differential double-meshing planetary gear reducer with a flexible cylindrical follower gear, comprising a housing (1), a fixed internal gear (14), a moving internal gear (13), a planetary carrier assembly (2), a drive shaft (11), and an output shaft (12); characterized in that: The planetary carrier assembly (2) is installed inside the housing (1). One side of the housing (1) is rotatably connected to the output shaft (12) through the center of bearing one (15), and the other side of the housing (1) is equipped with a power shaft (11). One end of the power shaft (11) extends into and is connected to the planetary carrier assembly (2), and its end is rotatably connected to the output shaft (12) through bearing four. A movable internal gear (13) is rotatably mounted inside the housing (1) on the side near the output shaft (12), and the movable internal gear (13) is fixed to the output shaft (12). A fixed internal gear (14) is fixed inside the housing (1) on the side near the power shaft (11). The planetary carrier assembly (2) includes a left clamping plate (21) and a right clamping plate (22) arranged in parallel. The right clamping plate (22) is rotatably connected to the end cover on the side of the housing (1) near the power shaft (11) via a bearing 2. A plurality of planetary columns (23) are distributed between the left clamping plate (21) and the right clamping plate (22). One or more of the planetary columns (23) are fitted with planetary gears (24), and the remaining planetary columns (23) are fitted with follower gears (3). The planetary gears (24) mesh with the inner sides of the moving internal gear (13) and the fixed internal gear (14). The follower wheel (3) is configured as a flexible structure, and the follower wheel (3) rolls in contact with the tooth tip circles of the moving internal gear (13) and the fixed internal gear (14) simultaneously. The power shaft (11) is fixed to the left clamping plate (21) and the right clamping plate (22) in the planetary carrier assembly (2) by a key; The planetary gear (24) meshes with the fixed internal gear (14) and the moving internal gear (13) simultaneously to form a double meshing transmission. The tooth difference of the double meshing transmission is a single tooth difference or two or more tooth differences.

2. The non-eccentric single / multi-tooth difference double-meshing planetary gear reducer with a flexible cylindrical follower wheel according to claim 1, characterized in that: The power shaft (11) is rotatably connected to the left clamping plate (21) in the planetary carrier assembly (2), and the left clamping plate (21) is equipped with a bearing three, and the power shaft (11) is fixed to the inner ring of the bearing three; A sun gear (25) is machined or installed on the power shaft (11), and the planetary gear (24) meshes with the sun gear (25).

3. The non-eccentric single / multi-tooth difference double-meshing planetary gear reducer with a flexible cylindrical follower wheel according to claim 2, characterized in that: The sun gear (25), planetary gear (24), fixed internal gear (14), and moving internal gear (13) are all made of high-strength alloy steel.

4. The non-eccentric single- or multi-tooth differential double-meshing planetary gear reducer with a flexible cylindrical follower wheel according to claim 1, characterized in that: The follower wheel (3) includes a first flexible column (31) and a second flexible column (32) arranged at the same center. The first flexible column (31) and the second flexible column (32) are fixed together by a bushing (33). The first flexible column (31) rolls in contact with the moving internal gear (13), and the second flexible column (32) rolls in contact with the fixed internal gear (14).

5. The non-eccentric single- or multi-tooth differential double-meshing planetary gear reducer with a flexible cylindrical follower wheel according to claim 4, characterized in that: The fixed internal gear (14) and the moving internal gear (13) have equal or unequal tooth tip circles. When the tooth tip circles of the two gears are equal, the flexible column one (31) and flexible column two (32) of the follower wheel (3) are of equal diameter and are adapted to mesh with the fixed internal gear (14) and the moving internal gear (13). When the tooth tip circles of the two gears are unequal, the flexible column one (31) and flexible column two (32) of the follower wheel (3) are of two concentric elastic rims of unequal diameter and are adapted to mesh with the corresponding fixed internal gear (14) and the moving internal gear (13) respectively.

Images