A composite harmonic gear transmission

Abstract

The application discloses a composite harmonic gear transmission device, belongs to the technical field of mechanical transmission, and can solve the problems of small transmission ratio, high machining difficulty and high machining cost of the existing harmonic gear transmission device. The device comprises a driving motor, a steel wheel, a flexible gear, a sun gear wave generator and a planetary gear wave generator. The driving motor comprises a motor body and a power shaft arranged on the motor body. One end of the steel wheel is fixed with the motor body, and the steel wheel is provided with a first inner gear ring. The flexible gear is arranged on the inner side of the steel wheel and is provided with a second inner gear ring. The power shaft extends into the inner side of the flexible gear and is coincident with the central shafts of the steel wheel and the flexible gear. The sun gear wave generator is located on the inner side of the flexible gear and is sleeved on the power shaft. The power shaft can drive the sun gear wave generator to rotate. The planetary gear wave generator is arranged between the sun gear wave generator and the flexible gear and is engaged with the sun gear wave generator, the first inner gear ring and the second inner gear ring. The application is used for a harmonic reducer.

Description

Technical Field

[0001] This invention relates to a composite harmonic gear transmission device, belonging to the field of mechanical transmission technology. Background Technology

[0002] Harmonic gear transmission technology is a new transmission technology that emerged in the 1950s with the development of space science and aerospace technology. Harmonic gear transmission devices are characterized by simple structure, small size, light weight, low noise, high load-bearing capacity, and high transmission accuracy, and are widely used in robotics, space technology, energy, radar communication, machine tools, automobiles and other fields.

[0003] Harmonic gear transmission devices mainly consist of three components: a wave generator, a flexible gear, and a rigid gear. Since harmonic transmission relies on a wave generator with an elliptical axis to force the flexible gear to undergo elastic deformation, which then meshes with the rigid gear, the flexible gear, due to its thin-walled structure, small module, and large number of teeth, is highly susceptible to breakage at the teeth and thin-walled sections during transmission. This directly affects the reducer's load-bearing capacity and service life. When a harmonic gear transmission device of the same volume requires a large transmission ratio, traditional harmonic gear transmission devices can only achieve this by increasing the number of teeth on both the rigid and flexible gears. This results in even smaller meshing teeth between the rigid and flexible gears, increasing design complexity and manufacturing costs. Summary of the Invention

[0004] This invention provides a composite harmonic gear transmission device that can solve the problems of small transmission ratio, high processing difficulty and high processing cost of existing harmonic gear transmission devices.

[0005] This invention provides a composite harmonic gear transmission device, the device comprising:

[0006] A drive motor, including a motor body and a power shaft disposed on the motor body;

[0007] A steel wheel, one end of which is fixed to the motor body, the steel wheel having a first internal gear ring;

[0008] A flexible wheel is disposed inside the steel wheel, and the flexible wheel has a second internal gear ring; the power shaft extends into the inner side of the flexible wheel and coincides with the central axis of both the steel wheel and the flexible wheel;

[0009] A solar wave generator is located inside the flexible wheel and is sleeved on the power shaft; the power shaft can drive the solar wave generator to rotate.

[0010] A planetary gear wave generator is disposed between the solar gear wave generator and the flexible gear, and meshes with the solar gear wave generator, the first internal gear ring, and the second internal gear ring.

[0011] Optionally, the flexible wheel is provided with multiple elastic telescopic structures, one end of which is connected to the inner wall of the flexible wheel and the other end is connected to the outer wall of the second internal gear ring.

[0012] Optionally, multiple elastic telescopic structures are evenly distributed around the inner wall of the flexible wheel.

[0013] Optionally, the elastic telescopic structure includes a first bending section, an arc-shaped connecting section, and a second bending section;

[0014] One end of the first bent section is connected to the inner wall of the flexible wheel, and the other end is connected to one end of the arc-shaped connecting section. The other end of the arc-shaped connecting section is connected to one end of the second bent section, and the other end of the second bent section is connected to the outer wall of the second internal gear ring.

[0015] The bending directions of the first bending segment and the second bending segment are opposite.

[0016] Optionally, a ball bearing is provided between the flexible wheel and the steel wheel, and the flexible wheel is slidably connected to the steel wheel through the ball bearing.

[0017] Optionally, there are multiple balls, and the multiple balls are arranged around the outer wall of the flexible wheel.

[0018] Optionally, the device further includes:

[0019] A front cover is mounted on the flexible wheel and is detachably connected to the flexible wheel; the flexible wheel outputs power through the front cover.

[0020] Optionally, the outer end of the front cover is provided with an output shaft mounting position for mounting an external output shaft for shaft drive.

[0021] The side wall of the front cover is provided with a pulley structure for cooperating with an external conveyor belt to perform synchronous belt drive.

[0022] Optionally, the steel wheel includes a chassis, and the steel wheel is fixed to the motor body via the chassis; the power shaft passes through the chassis and extends into the sun gear wave generator, and the power shaft and the chassis are spaced apart.

[0023] Optionally, the device further includes:

[0024] The connecting plate is used to fix the chassis of the steel wheel to the motor body.

[0025] The beneficial effects that this invention can produce include:

[0026] (1) The composite harmonic gear transmission device provided by this invention creatively combines a single-stage planetary gear train and a harmonic gear train within a single-stage platform. Compared with harmonic gear transmission devices of the same size, the transmission device of this invention has a compact and small structure, and its transmission ratio increases exponentially. Furthermore, since this invention designs the planetary flexible gear as an internal gear ring, it avoids the difficulties in machining the thin-shell external gear of the flexible gear, and also avoids the stringent requirements on the material of the flexible gear.

[0027] (2) The composite harmonic gear transmission device provided by the present invention uses a planetary gear wave generator as the transmission medium to enable differential meshing transmission between the flexible wheel and the steel wheel. Compared with the prior art, which uses the rotation of a conventional wave generator to force the flexible wheel to deform, and uses the change of the deformed part of the flexible wheel controlled by the wave generator to enable differential meshing transmission between the external teeth of the flexible wheel and the internal teeth of the steel wheel, the transmission device of the present invention avoids mechanical fatigue and damage caused by continuous deformation of the flexible wheel, making the transmission more reliable and achieving a repeatability accuracy of 10μm.

[0028] (3) The composite harmonic gear transmission device provided by the present invention adopts a circumferential elastic deformation design in the structure of the flexible wheel, that is, multiple elastic expansion and contraction structures are evenly distributed around the inner wall of the flexible wheel. This method based on the circumferentially distributed elastic expansion and contraction structure avoids the stress concentration phenomenon in the cylinder caused by the torsional deformation of the conventional flexible wheel during meshing.

[0029] (4) The composite harmonic gear transmission device provided by the present invention is designed with a separate indirect connection structure between the flexible wheel and the output end of the front cover. Under the condition of large load at the output end of the device, the front cover bears the larger load, thereby reducing the load on the flexible wheel, making the flexible wheel body less prone to deformation and damage, and thus extending the service life of the flexible wheel. At the same time, the present invention is designed to connect and fix the flexible wheel to the separate front cover, which can be directly connected to the transmission or indirectly connected to the synchronous belt.

[0030] (5) The composite harmonic gear transmission device provided by the present invention has fewer parts and a simple structure, making it suitable for mass production of metal or plastic molds, thereby reducing production costs. Attached Figure Description

[0031] Figure 1 An exploded view of the composite harmonic gear transmission device provided in an embodiment of the present invention;

[0032] Figure 2 This is a modular assembly diagram of a composite harmonic gear transmission device provided in an embodiment of the present invention;

[0033] Figure 3 A cross-sectional view of the composite harmonic gear transmission device provided in an embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the flexible wheel structure provided in an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the structure of the flexible wheel, steel wheel, and wave generator provided in an embodiment of the present invention.

[0036] List of components and reference numerals:

[0037] 11. Drive motor; 12. Steel wheel; 13. Flexible wheel; 131. Elastic telescopic structure; 14. Sun gear wave generator; 15. Planetary gear wave generator; 16. Ball bearing; 17. Front cover; 171. Output shaft mounting position; 172. Pulley structure; 18. Connecting plate. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the embodiments, but the present invention is not limited to these embodiments.

[0039] This invention provides a composite harmonic gear transmission device, such as... Figures 1 to 5 As shown, the device includes:

[0040] The drive motor 11 includes a motor body and a power shaft mounted on the motor body. The drive motor 11 can be a stepper motor.

[0041] The steel wheel 12 is fixed at one end to the motor body, and the steel wheel 12 has a first internal gear ring. This steel wheel 12 can be referred to as a gear ring steel wheel.

[0042] A flexible gear 13 is disposed inside the steel wheel 12, and the flexible gear 13 has a second internal gear ring; the drive shaft extends into the inside of the flexible gear 13 and coincides with the central axis of both the steel wheel 12 and the flexible gear 13. This flexible gear 13 can be called a planetary flexible gear.

[0043] The solar wave generator 14 is located inside the flexible gear 13 and is sleeved on the power shaft; the power shaft can drive the solar wave generator 14 to rotate; the planetary wave generator 15 is located between the solar wave generator 14 and the flexible gear 13, and meshes with the solar wave generator 14, the first internal gear ring and the second internal gear ring.

[0044] In this embodiment of the invention, the steel wheel 12 may include a chassis, and the steel wheel 12 is fixed to the motor body through the chassis; the power shaft passes through the chassis and extends into the sun gear wave generator 14, and the power shaft and the chassis are spaced apart.

[0045] The drive motor 11 is connected to the sun gear wave generator 14 as the power input terminal. The sun gear wave generator 14 engages with the gear ring steel wheel 12 through the planetary gear wave generator 15 to form a single-stage planetary gear transmission. Then, the planetary flexible gear 13 engages with the gear ring steel wheel 12 through the planetary gear wave generator 15 for differential gear transmission.

[0046] This invention creatively combines a single-stage planetary gear train and a harmonic gear train within a single platform. Compared to harmonic gear transmission devices of the same size, the transmission device of this invention has a compact and small structure, and its transmission ratio increases exponentially. Specifically, the transmission ratio of the transmission device of this invention can be calculated using the following formula:

[0047]

[0048] Among them, i 复 For compound harmonic gear transmission, the reduction ratio is i. 行 For the planetary gear transmission subtraction ratio; i 谐 Zg is the reduction ratio of the harmonic gear transmission; Zs is the number of teeth on the steel wheel (12 teeth); Zr is the number of teeth on the sun gear wave generator (14 teeth); Zr is the number of teeth on the flexible wheel (13 teeth).

[0049] This invention uses a planetary wave generator 15 as the transmission medium to enable differential gear meshing between the flexible wheel 13 and the steel wheel 12. Compared to the prior art, which uses the rotation of a conventional wave generator to force deformation of the flexible wheel 13, and utilizes the change in the deformed part of the flexible wheel 13 controlled by the wave generator to achieve differential gear meshing between the external teeth of the flexible wheel 13 and the internal teeth of the steel wheel 12, the transmission device of this invention avoids mechanical fatigue and damage caused by the continuous deformation of the flexible wheel 13, making the transmission more reliable and achieving a repeatability accuracy of 10μm. Furthermore, because this invention designs the planetary flexible wheel 13 as an internal gear ring, it avoids the difficulties in machining the thin-shell external teeth of the flexible wheel 13, and also avoids stringent requirements on the material of the flexible wheel 13.

[0050] Furthermore, the device also includes a connecting plate 18, through which the chassis of the steel wheel 12 is fixed to the motor body. In practical applications, the chassis of the steel wheel 12, the connecting plate 18, and the motor body can be fixed by screw connection.

[0051] refer to Figure 1 and Figure 3 As shown, a ball bearing 16 is provided between the flexible wheel 13 and the steel wheel 12, and the flexible wheel 13 is slidably connected to the steel wheel 12 through the ball bearing 16. In practical applications, multiple ball bearings 16 can be provided, and multiple ball bearings 16 are arranged around the outer wall of the flexible wheel 13.

[0052] refer to Figure 4 As shown, the flexible wheel 13 is provided with multiple elastic telescopic structures 131. One end of the elastic telescopic structure 131 is connected to the inner wall of the flexible wheel 13, and the other end is connected to the outer wall of the second internal gear ring. Furthermore, the multiple elastic telescopic structures 131 are evenly distributed around the inner wall of the flexible wheel 13.

[0053] The embodiments of the present invention do not limit the specific number and shape of the elastic telescopic structure 131, and those skilled in the art can set it according to specific circumstances. In practical applications, the elastic telescopic structure 131 can be provided as a first bending segment, an arc-shaped connecting segment, and a second bending segment; one end of the first bending segment is connected to the inner wall of the flexible wheel 13, and the other end is connected to one end of the arc-shaped connecting segment, the other end of the arc-shaped connecting segment is connected to one end of the second bending segment, and the other end of the second bending segment is connected to the outer wall of the second internal gear ring; the bending directions of the first bending segment and the second bending segment are opposite.

[0054] The flexible wheel 13 provided by this invention adopts a circumferential elastic deformation design, that is, multiple elastic telescopic structures 131 are evenly distributed around the inner wall of the flexible wheel 13. This method based on the circumferentially distributed elastic telescopic structures 131 avoids the stress concentration phenomenon in the cylinder caused by torsional deformation during meshing of conventional flexible wheels 13.

[0055] refer to Figure 1 and Figure 2 As shown, the device further includes:

[0056] The front cover 17 is mounted on the flexible wheel 13 and is detachably connected to the flexible wheel 13; the flexible wheel 13 outputs power through the front cover 17.

[0057] Furthermore, the outer end of the front cover 17 is provided with an output shaft mounting position 171 for mounting an external output shaft for shaft drive; the side wall of the front cover 17 is provided with a pulley structure 172 for cooperating with an external conveyor belt for synchronous belt drive.

[0058] This invention designs a separate, indirect connection structure between the flexible wheel 13 and the output end of the front cover 17. This allows the front cover 17 to bear a larger load under heavy load conditions at the device's output end, thereby reducing the load on the flexible wheel 13, making it less prone to deformation and damage, and extending its service life. Simultaneously, the flexible wheel 13 is fixedly connected to the separate front cover 17, which can be directly connected to the transmission or indirectly connected to a synchronous belt. Furthermore, the transmission device of this invention has fewer parts, a simple structure, and is easy to assemble, making it suitable for mass production using metal or plastic molds, thus reducing production costs.

[0059] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A composite harmonic gear transmission device, characterized in that, The device includes: A drive motor, including a motor body and a power shaft disposed on the motor body; A steel wheel, one end of which is fixed to the motor body, the steel wheel having a first internal gear ring; A flexible wheel is disposed inside the steel wheel, and the flexible wheel has a second internal gear ring; the power shaft extends into the inner side of the flexible wheel and coincides with the central axis of both the steel wheel and the flexible wheel; A solar wave generator is located inside the flexible wheel and is sleeved on the power shaft; the power shaft can drive the solar wave generator to rotate. A planetary gear wave generator is disposed between the solar gear wave generator and the flexible gear, and meshes with the solar gear wave generator, the first internal gear ring, and the second internal gear ring; The flexible wheel is provided with multiple elastic telescopic structures. One end of each elastic telescopic structure is connected to the inner wall of the flexible wheel, and the other end is connected to the outer wall of the second internal gear ring. The elastic telescopic structure includes a first bending section, an arc-shaped connecting section, and a second bending section; One end of the first bent section is connected to the inner wall of the flexible wheel, and the other end is connected to one end of the arc-shaped connecting section. The other end of the arc-shaped connecting section is connected to one end of the second bent section, and the other end of the second bent section is connected to the outer wall of the second internal gear ring. The bending directions of the first bending segment and the second bending segment are opposite; The device further includes: A front cover is mounted on the flexible wheel and is detachably connected to the flexible wheel; the flexible wheel outputs power through the front cover. The outer end of the front cover is provided with an output shaft mounting position for mounting an external output shaft for shaft drive. The side wall of the front cover is provided with a pulley structure for cooperating with an external conveyor belt to perform synchronous belt drive.

2. The apparatus according to claim 1, characterized in that, Multiple elastic telescopic structures are evenly distributed around the inner wall of the flexible wheel.

3. The apparatus according to claim 1, characterized in that, A ball bearing is provided between the flexible wheel and the steel wheel, and the flexible wheel is slidably connected to the steel wheel through the ball bearing.

4. The apparatus according to claim 3, characterized in that, There are multiple balls, and the multiple balls are arranged around the outer wall of the flexible wheel.

5. The apparatus according to claim 1, characterized in that, The steel wheel includes a chassis, and the steel wheel is fixed to the motor body through the chassis; the power shaft passes through the chassis and extends into the sun gear wave generator, and the power shaft and the chassis are spaced apart.

6. The apparatus according to claim 5, characterized in that, The device further includes: The connecting plate is used to fix the chassis of the steel wheel to the motor body.

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